Why do men have greater variance than women in mental test scores? Hedges and Nowell (1995) write that

  Sex differences in central tendency, variability, and numbers of high
  scores on mental tests have been extensively studied. Research has not
  always seemed to yield consistent results, partly because most studies
  have not used representative samples of national populations. An
  analysis of mental test scores from six studies that used national
  probability samples provided evidence that although average sex
  differences have been generally small and stable over time, the test
  scores of males consistently have larger variance. Except in tests of
  reading comprehension, perceptual speed, and associative memory, males
  typically outnumber females substantially among high-scoring
  individuals.

However, they don't really say anything about the reason for this aside from that "Our results shed little light on the origins of sex differences in [...] variability" (p45).

What theories are there of the reasons for this sex difference in variability on mental tests, and how strong is the evidence to support these theories?

I've heard two theories related to genetics. Mental traits are massively polygenic (many genes with tiny effects). Men (XY) do not have a duplicate X chromosome like women (XX), which means that mutations to an X chromosome that disrupt typical gene expression can affect men more than women, driving variance in mental scores. The second theory is related to the fact that individual men are less likely to pass on their genes than individual women. Counter-intuitively, most of our ancestors are women. Men may have evolved a riskier genetic strategy that produces more high and low cognitive scores in phenotypes. Consider that men also take more risks. This is a behavioral outcome that may have emerged from the same selection pressure.

See also:

https://en.wikipedia.org/wiki/The_Bell_Curve

https://www.amazon.com/Intelligence-That-Matters-Stuart-Ritchie/dp/1444791877


Neuronal differences of linguistic statements Assuming that the brain (structure) is only constructed using neurons and synapses, then what is the difference between the following linguistic statements from a 'mechanical point of view'?

Bob is a builder.
Bob should be a builder.
Bob must be a builder.

In each statement, there are the same "neurons" involved: "Bob" and "builder". I am trying to understand how both neurons could be connected/modelled in each statement in order to differentiate between the semantics.

Your question reduces to "what are the neural mechanisms behind language?", which is very much a work in progress.

The only neural model of language that I currently know of is the Semantic Pointer Architecture (SPA), which is largely theoretical and only has some super basic examples.

Basically, the SPA represents language as vector manipulation. The vectors are represented in neurons using the Neural Engineering Framework.

For more details on how this is done, check out "How to Build a Brain" by Chris Eliasmith and the work by Peter Blouw who is trying to solve part of this problem with his PhD thesis.


How to detect which memory is being used when answering a yes or no question? I am asking participants some questions on a form. I have to know which kind of memory they are using when answering these questions. I am having difficulty deciding this. Is there any special technique to determine this?

For example, consider these questions :

Is your name Majid?
Is the memory used semantic or episodic? I know that most probably everyone would say semantic because there is no event being recalled, but I am not sure if remembering own's name is possible without recalling an event.
Is your hair black?
This one is only available while thinking of a memory, but like the last one it could be semantic too.
Do you know how to ride a bike?
This one could be semantic or episodic because I might recall an event of riding a bike and then answer.  Or it could even be procedural memory as I might simulate riding a bike and then say, "Yes".

I am trying to figure out how do I assign each question one or more of the memory types?

I am using the memory types introduced by Squire in 2004.
The picture is from Fundamentals of Cognitive Neuroscience by Bernard Baars.

It depends whether the answers are well known facts. If I know well my name, the color of my hair and whether I can ride a bike then semantic memory is used to answer these questions. If I have a doubt whether I can ride a bike, then I may use other types of memory like episodic or even procedural to come up with an answer.

Also, I may use episodic memory to answer a specific question today, but if I have to answer the same question tomorrow I will probably use semantic memory because it has become a general fact that is stored in semantic memory.

  Semantic memory reflects our knowledge of the world around us, hence
  the term 'general knowledge' is often used. It holds generic
  information that is more than likely acquired across various contexts
  and is used across different situations.


Which are the specifics of a memory that are lost first? Background:
In the last few days, I came across an experience that made me wonder how our brain manages "memory resources".

As time progresses further from an experience I've had in my life, I realize that I have begun to forgot details that are important and supposed to be "kept", not lost since I was able to recall them in the first days following the event.

I remember what happened, who was present, and why it happened, but I'm beginning to lose track of "when" the event happened.

This may be a filtering process or a defense mechanism, but in any case, I'm not focusing on the reason behind that, rather I'm interested in avoiding such "holes" in memory in the future.

In a generalized way, given the facts that we can obtain by answering the questions "what", "why", "who" and "when", which of these are the first facts to be forgotten?

I was taught that recall and forgetting are somewhat worse for episodic memories as compared to semantic memories. I'm having trouble finding a supportive reference now, but that may be due to how basic the concept is (or it may just be wrong). The example I recall was the difference between remembering how to ride a bike vs. remembering the experience of learning to ride a bike – one expects more people to remember how to ride a bike than to remember learning how. This isn't the cleanest example of two different kinds of memories, because knowing how to ride a bike is also more likely an implicit, procedural memory.

In any case, forgetting "when" seems likely if this entails the circumstantial aspects of the event. If it's not especially important that the event in memory happened at a particular time or in a particular situation, those elements of the episodic memory could be forgotten quite readily. I don't think "when" information is categorically forgettable though, as I can imagine some memories being tied very closely to that info – e.g., memories about parties on holidays or birthdays.


The psychology of disproportioned people in artwork Hitler was an artist, unbeknownst to  some people. He painted and sketched. In his work, the people were disproportionately large within any given scene. Given his extreme personality, I have often pondered about this. Perhaps an over exaggeration of people in his artwork reflected his own grandiosity about his position in the world.

Is there some connection between the psychology of consistently mistaking the proportional  size of people in art work and mental health?

I have been drawing for more than twenty years and have observed many people learn how to draw. Getting human (or any) proportions right is the one most difficult part for most people, and that Hitler, who made a living as an artist for years and produced two to three thousand drawings, sketches, watercolors, and oil paintings (Price, 1983), maybe drew people too large in some of them does, it would seem, not reflect anything but his level of artistry – or the expressionistic and new objectivist styles popular at the time: other expressionistic and post-expressionistic artists didn't paint very realistic, either.

Deducing psychopathology from artistic output is at least difficult. "The primary assumptions of art psychopathology theories are unreliable since, as Prinzhorn shows, emotionally troubled people are capable of producing wondrous artworks which compare favorably with the creations of artists and children." (Betts, 2006) Hans Prinzhorn, a German psychiatrist and art historian, was entrusted with caring for the collection of art by mental patients begun by Emil Kraepelin in 1919 and expanded it to more than 5000 works in the following years. He published a book, Artistry of the Mentally Ill (1922), in which he analysed the paintings from his collection and found no differences to "normal" art.

Prinzhorn attempted to discern the differences between art by healthy individuals and "outsider art", as the artistic output by mentally ill people came to be called, in a more subjective manner. But first experimental results were contradictory as well. In an experiment, art teachers, mental health professionals, and laypeople, were all unable to discriminate drawings by schizophrenic or healthy children (Rubin & Schachter, 1972). The same group of researchers again found that judges discriminated at levels of chance when they were presented with art by schizophrenic and healthy mothers (Rubin, Ragins, Schachter & Wimberly, 1979). But in other experiments by another research group (Ulman & Levy, 1968, 1984; Levy & Ulman, 1974), judges were able to identify art by mentally ill adults and could even be trained to increase discriminative accuracy.

Discriminative ability seems to depend on what aspect of the artwork the judges look at. In a meta-analysis, Susanne Hacking and David Foreman (2001) identify a number of scales (thematic, quality, shape, color, reality, energy, complexity, composition etc.) and found that two of them (content and body detail, with effect sizes of 0.88 and 0.84 respetively) were able to discriminate patients and healthy controls. Using her own instrument, Hacking (1999) was able to correctly identify psychopathology from artwork with 80-90% accuracy by looking at use of color, line quality, and use of the drawing space.

Even in successful experiments, proportion does not seem to be a distinguishing characteristic of psychopathological art. And it is unlikely that other aspects of Hitler's art would show aspects of psychopathology, because, as he himself stated, as a professional artist his works were dictated by this customers: "I paint that which the people want to buy." (Price, 1983)

Sources:

Betts, D. J. (2006). Art therapy assessments and rating instruments: do they measure up? The Arts in Psychotherapy, 33, 422-434.
Hacking, S. (1999). The Psychopathology of Everyday Art: A Quantitative Study (doctoral dissertation), University of Keele. Available online at http://www.wfmt.info/Musictherapyworld/modules/archive/stuff/papers/Hacking.pdf
Hacking, S., & Foreman, D. (2001). Psychopathology in paintings: A meta‐analysis of studies using paintings by psychiatric patients. British Journal of Medical Psychology, 74, 35-45.
Levy, B. I., & Ulman, E. (1974). The effect of training on judging psychopathology from paintings. American Journal of Art Therapy, 14, 24-25.
Levy, B. I., & Ulman, E. (1984). An experimental approach to the judgment of psychopathology from paintings. American Journal of Art Therapy, 23, 47-52.
Price, B. F. (1983). Adolf Hitler als Maler und Zeichner: Ein Werkkatalog der Ölgemälde, Aquarelle, Zeichnungen und Architekturskizzen. Zug: Gallant.
Prinzhorn, H. (1922). Bildnerei der Geisteskranken: Ein Beitrag zur Psychologie und Psychopathologie der Gestaltung. Berlin: Springer.
Rubin, J. A., Ragins, N., Schachter, J., & Wimberly, F. (1979). Drawings by schizophrenic and non-schizophrenic mothers and their children. Art Psychotherapy, 6, 163–175. doi:10.1016/0090-9092(79)90040-1
Rubin, J. A., & Schachter, J. (1972). Judgments of psychopathology from art productions of children. Confinia Psychiatrica, 15(3-4), 237-250.
Ulman, E., & Levy, B. I. (1968). An experimental approach to the judgment of psychopathology from paintings. Bulletin of Art Therapy, 8, 3-12.


How to calculate the confidence interval for $d^\prime$ (d prime)? I have an experiment with $N$ signal trials and $M$ no signal trials and I have measure the number of hits $nHit$ and the number of false alarms $nFA$. From this I can compute the probability of a hit $p(Hit)$, the probability of a false alarm $p(FA)$, and the index of sensitivity $d^\prime$. Specifically, I define $d^\prime=z(p(Hit))-z(p(FA))$ where $z(.)$ is the inverse of the normal distribution cumulative density function.

I can also find the confidence intervals of $p(Hit)$ and $p(FA)$ with the inverse of the binomial distribution cumulative density function. Is there a similar way of calculating the confidence interval of $d^\prime$ that doesn't involve resampling the data (e.g., bootstrapping).

I haven't done much d-prime stuff for a long time, but perhaps check out the discrim function in the sensR package in R.

http://www.inside-r.org/packages/cran/sensR/docs/discrim

For example, if I understand correctly you could pass arguments like the following: a person had 60 items correct out of 100 and null hypothesis d-prime is 0 (you can specify either a null d-prime or a null probability of correct).

library(sensR)
discrim(correct = 60, total = 100, d.prime0=0)

This produces the  following output:

Estimates for the duotrio discrimination protocol with 60 correct
answers in 100 trials. One-sided p-value and 95 % two-sided confidence
intervals are based on the 'exact' binomial test.

        Estimate Std. Error Lower  Upper
pc         0.600    0.04899   0.5 0.6967
pd         0.200    0.09798   0.0 0.3934
d-prime    1.115    0.31360   0.0 1.6958

Result of difference test:
'exact' binomial test:  p-value = 0.02844
Alternative hypothesis: d-prime is greater than 0

I.e., you appear to get a lower and upper confidence interval on d-prime (e.g., 0 to 1.6958). The confidence interval can be specified with the conf.level argument but defaults to 0.95. There's more details in Christensen (2015).

Christensen, R. H. B. (2015). Statistical methodology for sensory discrimination tests and its implementation in sensR. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.192.6348&rep=rep1&type=pdf


Family happiness Vs Career happiness Common knowledge accepts that there are two conflicting types of happiness, one attained through a good family and a second one attained through a successful career. These paths of happiness, since they require the same resources, are conflicting and somebody must choose the one over the other. This point is best illustrated through the movie The Family Man. Of course there are exceptions where both types of happiness are combined very well.

Please can you provide research or theories that can facilitate the clarification of the following questions:

Do we really have two different types of happiness?

Are the two happiness qualitatively different from each other?

And the most important question, is one of them much more superior than the other type?

I've looked into some papers about life happiness , and how work hapiness and familly hapiness can affect it.

A quick google search lead me to 2 articles :
Work, family, and happiness

Job Satisfaction and Family Happiness:
The Part-time Work Puzzle

I don't have the time to read them all , but from what I saw "work hapiness" and "family hapiness" are both parts of "life hapiness" but it seems like you could include as much hapiness sources as you want like "sport hapiness" , etc... (the last part is a personnal thought)

One important point seems to be that they're both different for men and women and are not exclusives.

For more details I'll invite you to reader the papers I linked you.

From what I've read I can tell that :

  Do we really have two different types of happiness?
  No , we don't. Hapiness is hapiness as a whole , but it comes piece by piece from everything you enjoy in your life.

  Are the two happiness qualitatively different from each other? Hapiness is formed from everything you enjoy in your life , so the quality of everything forming your hapiness is realy personnal. Though , the studies points that men and women react differently to the work/familly hapiness balance but here again everyone builds his hapiness his own way.

  Is one of them much more superior than the other type ? One could argue that familly , having kids , etc is the beautifulest thing in life , and so the best source of hapiness but as I said , it's a realy personal thing and I have no trouble imagining housewifes can be as happy as women working a lot and loving their work.


What are good examples of applying dynamical systems in cognitive science? I'm a mathematics and physics student very much interested in cognitive science. Recently I've been hearing about "a new approach" in cognitive science via dynamical system theory.

What are some good examples of using differential equations to model cognitive phenomena?
What papers would you recommend?

Given your background and interest in modeling, I would highly recommend The Cambridge Handbook of Computational Psychology. The book provides an overview for several of the prominent modeling paradigms in cogsci, including dynamical systems, as well as many concrete examples--albeit most using other computational paradigms.

Dynamical systems, to my knowledge, are most used in the field of motor control. Though to be honest, dyn systems is not 'my' paradigm, and most of my knowledge comes from the aforementioned book.

In particular, the chapter "Dynamical Systems Approaches to Cognition" by
G. Schoner gives this example that has always stuck in my mind:

  A highly illustrative example comes from the orientation behaviors of
  the common house ﬂy (Reichardt & Poggio, 1976; Poggio & Reichardt,
  1976). Flies orient toward moving objects, which they chase as part of
  their mating behavior. Detailed analysis revealed that the circuitry
  underlying this behavior forms a simple controller: a motion detection
  system fed by luminance changes on the ﬂy’s facet eye drives the ﬂight
  motor, generating an amount of torque that is a function of where on
  the sensory surface motion was detected. If the speck of motion is
  detected on the right, a torque to the right is generated. If the
  speck is detected on the left, a torque to the left is generated. The
  level of torque passes through zero when the speck is right ahead. The
  torque changes the ﬂight direction of the ﬂy, which in turn changes
  the location on the facet eye at which the moving stimulus is
  detected. Given the aerodynamics of ﬂies, the torque and its on-line
  updating generate an orientation behavior, in which the insect orients
  its ﬂight into the direction in which a moving stimulus is detected.


Why does cathodal tDCS (negative) produce sensation, while anodal tDCS (positive) does not? If neurons fire due to an intracellular influx of positive ions, why are the negative electrodes in tDCS felt more strongly than the others? For example, see "Reducing Procedural Pain and Discomfort Associated with Transcranial Direct Current Stimulation" by McFadden et al.

Short answer
The underlying mechanism(s) causing the differences between the effectiveness of anodic and cathodic neural stimulation are largely unknown.

Background
As far as I know, the exact difference between the effectiveness of cathodic versus anodic stimulation are largely unknown. For instance, in animals and humans, both anodic and cathodic pulses can evoke neural responses. In human cochlear implant users, the anodic phase is more effective than the cathodic phase. In contrast, in animals (guinea pigs, cats and ferrets) exactly the opposite is observed. The reason for this discrepancy is unclear (Machery & Cazals, 2016).

The authors in your linked article state (McFadden, 2011):

  We hypothesize that the mechanism behind this may be associated with a concentrated exiting of current from the scalp at the cathode.

This, honestly, makes little sense as that same current was injected at the anode, barred the electrode sizes were not different.

Reference
- Machery & Cazals, Adv Exp Med Biol (2016); 894:133-42
- McFadden et al., Brain Stimul (2011); 4(1): 38–42


How can we scientifically measure love? I want to understand the psychology of love, and I found the Triangular Theory of Love on Wikipedia from this question, which I think is very believable. However, there is a big section on mixed support where it only says a little bit about THAT love was measured, not HOW:

"Sternberg measured his theory on couples who were roughly the same age (mean age of 28) and whose relationship duration was roughly the same (4 to 5 years)."
"The two other most obvious problems with Sternberg's theory of love are as follows. The first is a question of the separate nature of the levels of love. The second is a question of the measures that have previously been used to assess the three levels of love."

Can we scientifically measure love (without just asking the lovers)? How?

One way to measure love is to look at behaviors that people engage in to express love.

Chapman (1995) theorized that there were five broad classes of behaviors that people would engage in to express love: (1) words of affirmation, (2) spending quality time, (3) giving gifts, (4) acts of service, and (5) physical touch.

Goff, Goddard, Pointer, and Jackson (2007) developed a survey instrument to measure expressions of love. They created a series of questions that were designed to measure one (and only one) of the different behaviors that Chapman laid out. These involved asking questions about how a lover does things like: "giving presents," "offers encouragement," "spends time with me," "holds my hand," and "does yard work."

The goal of this work was mainly to see if the Chapman classes of expressions of love matched the kinds of behaviors that people wanted in a lover. The researchers administered the survey to a few hundred people, and in general found that the Chapman classes were a good set of high-level descriptions. People who tended to want one kind of behavior in a lover, e.g., receiving words of affirmation, also wanted other kinds of behavior from that class, e.g., receiving compliments.

References

Chapman, G.D. (1995). The five love languages: how to express heartfelt commitment to your mate. Chicago, IL: Northfield Publ.

Goff, B. G., Goddard, H. W., Pointer, L., & Jackson, G. B. (2007). Measures of expressions of love. Psychological Reports, 101, 357-360.


How do the brains of savants such as Orlando Serrell and Temple Grandin compare to a standard brain? There are the examples of Orlando Serrell and Temple Grandin, who remember quite a lot, due to autism.

How do their brains compare to a standard brain?

See also: Partitions and Volume:

I believe the answer lies in minicolumnar morphology in the neocortex. It's been shown that the minicolumns of autsitics and gifted individuals have narrower minicolumns, with greater spacing between each minicolumn. It's speculated that this creates an increased ability to distinguish percepts. Here is a paper on the topic:

Casanova MF, Switala AE, Trippe J, & Fitzgerald M. (2007) Comparative minicolumnar morphometry of three distinguished scientists. Autism 11(6):557-69.

I recommend reading through more of Casanova's work on the topic if you're interested.


Where is knowledge of how the brain works stored? If we are our brains, and our brains know how they work, this means that this information is stored somewhere in the brain, like the inferior temporal cortex is the part of the brain that recognizes numbers.
Where is knowledge of how the brain works stored?

This type of knowledge is known as "semantic memory"; a type of "declarative memory". We don't yet know where semantic memory is stored in the brain, although there is evidence that hippocampal and/or parahippocampal structures are required to store semantic memory.

The fine details of exactly what a "memory" is in terms of neurobiology, where and how it is stored, and how it is retrieved is an area of neuroscience that is currently under very active research. However, our knowledge is very rudimentary at present.


To what degree does environment govern the severity of symptoms in schizophrenia? From what I understand about the physiology of schizophrenia it is thought to be caused by chemical imbalances resulting from genetic factors, fueled by environmental factors. I've garnered that environmental factors can play a large role in how a person reacts to the disease.

As an example: a person with a genetic predisposition towards schizophrenia is raised in an abusive household with his parents yelling everyday, they will definitely become angry and more stressed out, which one might assume would lead to their eventual psychotic break. Is this 100% correct? Another person who might be less stressed out, probably raised in a normal family, could potentially experience troubling symptoms before a complete psychotic break. Is this a valid assumption or observed pattern in those who suffer from the disease?

So, if environmental factors can contribute to the onset of schizophrenia, could the removal of these factors lessen the symptoms? Take for example Jared Loughner, he will be spending life in prison. With time away from society, with the stresses of life removed, and (given the correct medication), could incarcerated schizophrenia patients' symptoms be ameliorated by this change in social situation?

Any info on this?

I think reading about the genain quadruplets should give you a clear idea of the effect of environment on schizophrenia. Basically, the quadruplets had a genetic disposition to this disorder and all 4 siblings were admitted at some point or another to the National Institute of Mental Health as schizophrenic. However, there were differences in the severity of the disorder in all 4 siblings due to the way they were treated by their parents, showing that despite genetic dispositions to a disorder, environmental factors do affect the severity of it.


What brain wave states are associated with hypnosis? What brain wave states are most correlated with deep hypnosis?

Hypnotic states are associated with increased theta wave activity. Hypnotically susceptible participants also exhibit hemispheric beta wave asymmetry, but non-susceptible participants do not (Sabourin, Cutcomb, Crawford and Pribram, 1990).

References

Sabourin, M. E., Cutcomb, S. D., Crawford, H. J., & Pribram, K. (1990). EEG correlates of hypnotic susceptibility and hypnotic trance: Spectral analysis and coherence. International Journal of Psychophysiology, 10(2), 125-142.


Can SSRI make things worse in the long term or cause delayed depression? I found two articles that mention that taking SSRI for depression can actually make the depression worse.

"Now Antidepressant-Induced Chronic Depression Has a Name: Tardive Dysphoria" on Psychology Today.
"Antidepressants Make Things Worse in the Long Term" on the Behaviorism and Mental Health blog.

Is this true? Can Tardive Dysphoria (delayed depression) be caused by SSRI?

They seem pretty convincing and I can't find anything against it but if it's true, it basically means that depression treatment is going back to the 60's before SSRI were invented.

Contrary to another post here, in my opinion and also that of an increasing majority of researchers studying this field, SSRIs and the so called 'antidepressant' drugs cause great harm.

Firstly here is a list of common side effects: Insomnia (which is common in depression anyway), increased anxiousness, feeling sick, indigestion, diarrhea or constipation, loss of appetite, fluctuations in weight, dizziness, blurred vision, dry mouth, excessive sweating, headaches, reduced sex drive, difficulty achieving orgasm, erectile dysfunction.

None of these are good effects which is why we don't give them to people who are 'healthy'. More importantly the devastating effect these side effects can have on a patients life could potentially be far more harmful than before the drug was taken, for example increased marital problems. According to Joanna Moncrieff these effects compound depression, and more importantly disturb the chemical balance in the the brain, and as a result compound or cause the very symptoms they are meant to cure. Central to this notion and the question presented here, the long-term use of SSRIs may causes what we call 'serotonin induced apathy', in other words, after initial positive effect of SSRIs (quiet possibly short-term placebo effect), patients become indifferent to their environments. Furthermore Long-term use of SSRIs leads to abnormal brain neurogenesis not seen in non-depressed samples, this is often taken to as proof of how SSRIs exert there action, or rather it was before 2008 (see below meta analysis). However it seems that this neurogenesis is less likely to be positive considering the negative effects and lack of efficacy SSRIs display.

The long-term use of SSRIs often leads to the development of apathy, which utimatley will lead many patients back into depression. The rate of relapse in people taking 'anti-depressants' is >40% while patients with placebo is roughly 24%. If that isn't bad enough at a 12 month follow up only <5% of patients are in remission for their depression. Why might this be? Well a 2008 meta-analysis by Kirsch et al found that all 'anti-depressants' are below clinical levels of acceptance, in other words no more effective than placebo. However it should be noted that in severe depression SSRIs are useful only!

The reason anti-depressants such as SSRIs are ineffective is because of the simplistic approach taken  to treatment with these drugs. The brain is not some 'big bag of chemicals', neurons  are not purely serotonergic in fact they often release multiple NTs. And crucially serotonin NT is used throughout the central nervous system, for more than mood regulation. The fact that SSRIs do not work over the long-term tells us the serotonin theory of depression is wrong. Perhaps more importantly roughly 10% of people in the UK are on 'anti-depressants', we can talk about over medicalisation of mental health, but the reality is large amounts of people are taking these drugs for large amounts of time (9-12 months recommend). This is not helped by the fact that governments are more interested in investing in cheap medical 'cures' than long-term methods with greater efficacy that cost more.

Sorry its so long, and I'm sorry its so short there is so much to say about how SSRIs don't work and how bad they are regarding people thinking they are getting effective cures, along with the neuroscience and discussions on publication bias. Its a fascinating topic, thanks for the question.


Do school teachers demand more from their children than other students? Lets assume that there is a group of students and one teacher (typical school situation).

Child of the teacher is in that group.

Is there any evidence, that school teachers demand more from their children than other children?

Is there any evidence, that children who are taught by parent-teacher achieve better/worse results than other students in same group?

From Personal Experience, teachers will demand more from their child if their child is in that class for a couple of reasons: To show the rest of the class that there is no favoritism towards the child, as well as to ensure that the child performs exceptionally in the class.

Whether they achieve better/worse results is dependent on the level that this "extra demand" is taken to. For example a child may feel like he's being treated unfairly, and act out as a result, or become overwhelmed by the amount of work. But if it is a reasonable increase in demand, then the student will surely benefit.


Can our brain do trigonometry? I was sitting in college today today doodling around as I was bored, when I drew an arrow onto my paper, Looking at the arrow, I predicted that the arrow would move in the direction it was facing. Then, I thought "How did I know it would move in that direction?". Being a programmer/game developer I know that to make an object move in a direction, you need to do trigonometry math, and I highly doubt that I can find the cosine and sine of a number in my head.

How did I know in which direction the object was going to travel?

Here is a diagram:

The brain doesn't do trig at all for this problem. It uses a lot of tricks to estimate the solution.

First we should be careful, though. Your example isn't an example of calculating the trig, it's an example of assuming or completing an image. This is in line with gestalt psychology, where the brain takes less information than necessary to truly know an answer and guesses the best solution based on several rules.

Now if our example is an actual moving object, such as a ball, we come to the aforementioned tricks.

One trick is constant re-estimation. Imagine you had a computer with a very naive way to calculate the movement of our ball - it looks at where the ball has come from and assumes a linear path. This path is probably wrong, but let's say we do this ~50 times a second. Each path is wrong, but they will be increasingly accurate, and each one may be sufficient to have a general idea of where the ball is headed, until it is accurate enough that we can catch the ball. Our brain probably does a lot better than a linear estimation, but it still takes some form of this shortcut, trading accuracy for a less difficult computation because we can redo and correct our calculations as we go.

Another trick is our short term knowledge of the path an object has taken and the fact that most objects take very simple paths. If I gave you a graph of the ball's movement from 0-10 seconds, chances are you can draw 10-20 seconds pretty accurately. This helps us with objects that are moving slowly or are far away, where we get to see them for long enough time to see an overall pattern.

These first two aren't so successful for predicting living organisms, which often move too fast and complexly for them. In this case, we largely rely on previous knowledge. We know few things leave the ground, and if they do they usually come down again very soon (often in an arc). We know most things accelerate downhill, decelerate uphill, and follow the curves of the surface they are on. For the things that are even less predictable, we learn to see the subtle preparatory movements involved: we see the slight turn of the leg before a runner changes direction, the crouch before a jump, the raising of wings before flying. Indeed when things don't follow these rules, or optical illusions make things appear to not follow these rules (rooms that look normal but are weirdly shaped), it amuses or confuses us.

Depending on the type of programming you do/your formal education, you may be very aware that when the optimal solution takes more resources to find than it is actually worth, programmers opt for estimations of near-optimal solutions. In a living creature, the priority is coming up with a solution that is near-optimal in enough time to react to potential danger (something flying towards you). In this way, the brain's sensory problem is an extreme version of the programming problem of coming 'close enough' in the time allotted. Specifically this is most similar to online problems where solutions must be optimal for an unknown amount of inputs as each input comes in.


How repeatable are cognitive science findings within the same individual? Thanks to this website, I've seen a number of papers and scholarly articles that deal with cognition. I'm interested in how repeatable the findings are that are discovered as a result of experiments.

For example, when a mechanical system is tested, it is tested to work the same way every single time:

A lock opens and closes when a key is turned.
A car door opens up to the maximum degree allowed by design.

How much is a cognitive system like a mechanical system? Will it work the same way every time?

For example, I'm thinking about the design of an experiment I've been reading about: The Ikea Effect Experiment. Volunteers are asked to assemble Ikea boxes and bid on the box after assembly. The experiment shows that people value things they built themselves more than things that are just offered to them.

Now if the machine-like definition of repeatability is applied to this experiment: Would test subjects value boxes they built themselves next time they do an experiment? How about next month? What about in 3 years? Would people in the 1940's have the same response?

Have there been any studies that deal with this "repeatability" question? For example, studies that used the same test subjects doing the same experiment multiple times?

Humans are, as you would expect, much noisier than physical systems. As such, replication of experiments in psychology is very important. Replication provides evidence that the original results were not spurious.

As pointed out in the comments, replication with the same subject pool is not always the way to go. Many tasks have learning effects, and so you would not expect to achieve the same results by re-administering the experiment.

There is a vast statistical literature on reliability testing. A good place to start would be at the Wikipedia article for Reliability (psychometrics)


How can depression and fear be effectively managed in people who know they will die soon? Are there any efficient ways to overcome the fear and depression before death  (supposing you know you are going to die soon) ?

I'm no expert on imminent death handling but I have some concepts to share. My suggestions are general suggestions that don't only apply for this scenario but that can be applied more generally, including that scenario.

Overcoming fear of death already is not easy, having to do it in an expedited fashion is even more challenging.

Fear of death comes from resistance to it, there are a lot of books that teach how to surrender to it to drop all resistance and the fear of death with it.

I would recommend reading about "impermanence" in Buddhism, the "dying before you die" concept, "the power of now", "spiritual enlightenment".

Those family of books on "spiritual enlightenment" and "power of now" teach you how to surrender and not resist to things you can't control.


When did the old term experimental reagent become experimental subject? I've read a paper on an experiment called "The Feeling of Being Stared at", which investigates a concept which on Wikipedia is called the psychic staring effect. It was first investigated by psychologist Edward B. Titchener in 1898.

The paper consistently refers to the experimental subjects as "reagents".

  "In some of the experiments, the distance between the experimenter and
  reagent was varied for the purpose of..."
  Page 3 of 6

I'm unfamiliar with this term to refer to subjects, and I assume it's because this is an old paper from 1913. My guess would be that the word means something or something that reacts, and subjects are subjected to stimuli. Is anyone familiar with this term being used generally in experiments around this time period or even today? And if so, when it fell out of fashion and replaced with what we use now: "subject".

Psychological theory has often metaphorically used terminology from the technology or science of its time.

Freud explains certain aspects of the psyche in terms of the steam engine, and psychologists of the late 20th century think of the brain in terms of computer science.

In your case Titchener and other psychologists of his time tried to grasp psychology in terms of chemistry: "a reagent is a substance which, because it has a capacity for certain reactions, is used to detect, examine, or measure other substances" (Schultz, 2013, p. 88). Historians of psychology assess this term as evidence for the mechanistic view inherent in the structuralist approach to psychology. For Titchener, the human proband is a recording instrument (Schultz, 2013, p. 88).

As psychology as a science has shifted to a new paradigm in the early 20th century, the term reagent slowly fell out of use. The latest use in a psychological context that I'm aware of is in the late 1920s.

Sources:

Schultz, D. (2013). A History of Modern Psychology (2nd ed). New York: Academic Press.


Double blindedness in a fully remote trial We are planning to do a fully remote clinical trial to test an online intervention for depression. We will be using a self-rated PHQ-9 at base-line, post intervention, and 90 days follow-up to test the efficacy of the intervention.

The participants wouldn't know if they are assigned to the experimental or the control group (so it is definitely single-blind). Since there is no investigator who will be assessing the depression severity, there is no source of any human bias there (since double-blind trials are designed to eliminate investigator bias).

I was wondering if this can be called a double-blind study. I have seen other fully remote trials with a similar design but they haven't mentioned the term double-blind anywhere. Considering the fact that it is the gold standard, I am surprised that investigators did not mention it in their paper. That is the source of my confusion.

Any thoughts are welcome. Thanks in advance.

Double blind basically consists when the patient does not know to which condition it belongs (control, treatment A, treatment B) and the professional does not know to which group he/she is administering the treatment (control, treatment A, treatment B).

The double-blind designation is not based on the fact that the initial level of depression is not assessed. (I guess you know it and it has been erroneously specified in the question).

In online studies this denomination is not usually used although of course it is not incompatible. (The issue is that this denomination is not usually used because the trial is not common either).

In short I do not see problem with the double blind designation.

On the other hand, it would be necessary to pay close attention to the clinical level and the characteristics of the intervention (you do not specify, is the intervention also remote?).

In any case sounds very interesting.


For an average adult, in general, if one knows they will wake up in the middle of a cycle--is it better to go to bed later? Let us say that one consistently goes to sleep at the same time every day, and sets an alarm for the same duration of sleep 7 hours and 45 minutes (e.g., 10:45pm to 6:30am).

One day, they get caught up in something, and are 30 minutes late to "bedtime." Is it better to wait 45-60 minutes to wake up at the same time (at the end of a cycle), refreshed, and not in the middle of a cycle, groggy?

I know there are some odd assumptions here, but if you could please either help edit or have better questions (or advice) to strike more at the heart of the matter--please do so. I think the largest assumption is the roughly 90 minutes sleep phase cycles at the end at least:

As a precursor, even if a stringent sleep schedule is absolutely followed, one still needs to practice other good sleep hygiene habits: avoiding blue light (or using a filter for screens), exercising regularly, eating healthy and attaining an overall equanimous mood (lack of distress). That, among other non-ideal factors, such as sleep disturbances could also result in a poor nights sleep. But the question was stated as if in a 'perfect vacuum.' Non-idealities are overlooked.

That being said, I am going off the aforementioned assumptions about religiously going to bed at 10:45 and waking at 6:30 every day--including weekends. Let's say this person could sleep for nine hours (9:15 TIB), and we can safely assume that an adequate nights sleep is 7:45 TIB. In other words, this person can be high-functioning on 7.5 hours of sleep (five phases).

→ Is it better to wait until 12:15? (Either way, 6:30 wakeup for work stays constant.) One deviant day--does it matter? When will the sleep debt be relinquished? Honestly, I didn't find any research remotely about it.

Let's go out on a limb, and say it doesn't matter given the ideal-vacuum conditions. Then how many deviations, say, twice a week--do matter? How many will lead to partial sleep deprivation? Still, the answer is unknown.

So I emailed sleep researchers from U.W. Madison and Stanford:

Going to sleep in the middle of a phase versus "catching" the next phase (with less sleep) for one night (subject)

  Hello Professor _______,

  I have question for you about making a bedtime choice, a deviation,
  from a consistent sleep schedule: For an average adult, in general, if
  one knows they will wake up in the middle of a cycle--is it better to
  go to bed later?

  Scenario1

  Get home late, and ready to be in bed at 11:15 PM. Must wake at 6:30
  for work.

  Scenario2

  Get home late, later, and ready to be in bed at 11:45 PM. Must wake at
  6:30 for work.

  The first is 30 minutes late. The second is 60. Let's say for this
  person that we can safely assume that an adequate nights sleep is 7:45
  TIB. In other words, this person can be high-functioning on exactly
  7.5 hours of sleep (while following a consistent sleep/wake routine).

  → Is it better to wait until 12:15?

  [...] I ask this question because I follow the routine above. I
  deviate 1-2 times a month, and either way usually take a nap before
  3PM to follow, but persistently wonder which is the ideal choice.

Prof. Responses

  Hi Adam,

  There is not easy answer, I do not know of direct evidence
  for one schedule over the other;  you are the best judge;  try the
  different schedules and  decide which one works for you (i.e. you feel
  better and you are “ready” to go)

  It may be that they are very
  similar; in any case, it is dangerous to assume 7 or 8 hours is what
  YOU  need

  Inter individual variability is huge, this is why each
  person is the best judge

~ C.C.

  Adam,

  Unfortunately, there is no good answer. The data for waking up in the
  middle of a cycle is sparse and doesn't offer good conclusions (the
  only reasonable one is that if it makes you feel better to wake up at
  the end of a cycle, that's probably a good thing). There are some
  circadian consequences of bouncing around a sleep onset time too much,
  with greater variability in onset time leading to more difficulty
  initiating sleep (and probably some other changes as well, though less
  well documented). Me, I'd stick with the earlier bed time that is
  closer to standard bedtime and get the extra sleep...

~ J.Z.

Going Further

Assess your ideal amount of sleep by taking a 'sleep vacation.' Over a two-week period, keep your consistent bedtime, but don't wake up with an alarm clock. Log. (See healthysleep.med.harvard.edu/need-sleep/what-can-you-do/assess-needs.)

How do you objectively analyze your sleep?

  There are two commonly used methods to assess sleep, Actigraphy
  and Polysomnography. Actigraphy is a non-invasive method of
  monitoring sleep and involves wearing wrist activity monitors, which
  are devices worn like a wristwatch that continuously record body
  movement (usually stored in 1-min epochs). [...] Actigraphy is useful for
  understanding sleep patterns as it is non-invasive and relatively
  easy to collect data over significant periods of time (commonly two
  weeks of monitoring).

  The second method is Polysomnography (PSG) which is a sleep
  study in which body functions such as EEG, eye movements,
  muscle activity and cardiac activity are measured. PSG provides
  information on sleep staging and is considered the “gold standard”
  for assessing sleep quality and quantity.

~ Sports Science Exchange (2013) Vol. 26, No. 113, page 2

→ DIY: https://sleepjunkies.com/features/the-ultimate-guide-to-sleep-tracking

Additional Resources

Phase Relationships between Sleep-Wake Cycle and Underlying Circadian Rhythms in Morningness-Eveningness
Modeling the Effects of Sleep Debt: On the Relevance of Inter-Individual Differences

Extra

https://faculty.ist.psu.edu/vhonavar/Papers/BIBM2017_YE.pdf


Do Big 5 or BIS/BAS personality theories propose that combinations of personality traits are meaningful? Personality traits tend to correlate. That is, the factors 'reward seeking', 'fun seeking' and 'drive' of the BIS/BAS scales are inter-correlated and similary in the Big 5 theory, the factor Neuroticism negatively correlates with Extraversion and Conscientiousness. (In the general population.)

I was wondering, does either of the personality theories (or any other personality theory) propose that there exists a balance between personality traits? Or that certain combinations of traits are meaningful. For example would high Neuroticism and high Extraversion describe some subgroup and be predictive in any way?

Here are a few ways of thinking about this:

Regression modelling - Main effects: When we predict an outcome of interest from multiple traits (e.g., the Big 5), we often get multiple significant parameters. For example, when predicting life satisfaction, low neuroticism and high extraversion tend to provide the strongest predictors, but there are also typically positive coefficients for the other factors. Thus, the coefficients imply a way of forming a personality composite to maximise prediction of an outcome.
Regression modelling - Interaction effects: You can examine interaction effects of multiple traits (e.g., is there a neuroticism by extraversion interaction in predicting life satisfaction). This is typically examined by including both the raw variables and the product of the two interacting variables. The significance of the product is used test for an interaction effect. That said, my general sense is that these kinds of interactions tend to be very small in comparison to the size of the main effects.
Type-based research: There are various conceptions of personality such as Type A and Type D personality. They often define a categorically distinct personality in terms of status on a number of traits. For example, Type D is defined as high negative affect and high social inhibition. Such type based approaches implicitly assume that it is useful and ideally meaningful to talk about such clusters of traits.
Higher level traits: Another way of thinking about correlated traits is in terms of an underlying higher level trait. This is proposed explicitly in hierarchical measures of personality such as the NEO-PI where there are 6 facets for each of the Big 5. Thus, the six conscientiousness facets are in some sense combined to form the overall conscientiousness factor (see facet versus factor prediction). In a less explicit, we can also see discussion of the Big 1 (a proposed higher level factor explaining some shared variance in the Big 5) as an implicit way of combining the Big 5.


What are existing theories on competing wills in the mind? To clarify a little further, I've read in different places that our brain could be composed of mini minds, that preform all sorts of actions.  Assuming this is valid I'd think that of these minds, some result in a composite or layering that results in our personality and an ultimate will that wins out to complete some action or decision, insomuch as a set of minds are inter-related in relation to some function.

I'm really just assuming from reading various articles and papers and some personal self reflection... but I'd imagine there is something to read in relation to this idea in some shape or form.... In other words I'm looking for more solid reading material, I'm not sure what I should be searching for.

Instead of pointing you to existing theories, which is (1) too advanced for you to understand at the current level of knowledge, and (2) too focused so that you don't have a big picture, why don't we just suggest you to read a textbook about cognition? It will solve both problems at the same time.

I recommend the book Cognitive Psychology, written by Strenberg, as the starting point. Cognition: Exploring the Science (author: Reisberg) is also a good one. If you are like me, you will realize how to make the question clearer just after some first few pages of reading.


If sleeping is related to 'saving information' you've experience, is forgetting related to more energy? So I was watching this youtube video (Only check 1:05 - 1:25) where it suggested we sleep because the brain needs rest to save/process all information we perceived throughout the day. I directly made the connection to my own body with the following thought:

  I can stay up for extended periods without the need of sleep. However, I easily and very quickly forget anything, almost like dementia, but if I try hard, I can remember it.

If the necessity of sleeping is related to the amount of information received, does forgetting information reduces that necessity? And does forgetting result in longer days without being tired?

Keep the jargon and technical details to a human level, please.

Short answer: No.

Long answer: The need for sleep is not a function of information received in any meaningful sense. Memory consolidation and forgetting processes are not thought of in terms of energy expense and conservation by any current cognitive science models, and lack of sleep will not necessarily cause you to go mad or die as such. Both are active processes; there's nothing inherently more energy-conserving about forgetting a memory than consolidating one, or vice versa.

Memory consolidation and forgetting processes in the brain are both, ultimately, physical changes like any other, which implies that energy must be spent in some sense. This energy is simply a thermodynamic quantity that has virtually nothing to do with how tired we feel or mental energy, however. Cognitively speaking, energy isn't a well-defined or scientifically meaningful term, so it's not particularly surprising that it ended up on a list of "five simple questions that science can't answer."

For an example of an active inhibitory forgetting mechanism with references, see my question about retrieval-induced forgetting. If you want to know about memory and the study of memory, I recommend reading Baddeley, Eysenck and Anderson's comprehensive Memory (2009). While it does not directly deal with sleep in depth, it will equip you to ask the right questions about how sleep relates to memory and learning.


What is actually happening with neuron during refractory period? Sorry for a very rookie question. I've got an interest in spiking neural networks and therefore I started learning about different neuron models like Leaky integrate-and-fire, Izhikevich, etc. But then I became interested in the biological nature of all the processes happening "under the hood".

What I really don't get at this point in time, is what is happening with the neuron while it is in its refractory state? Most of the sources say something like during the refractory period, a neuron is unable to produce new spikes. Yes, I get it. But what happens internally? I.e. how the incoming impulses are handled during this time?

I mean, a neuron is constantly receiving impulses (spikes) from other neurons it's bound with via synapses. So hundreds (or even thousands) of presynaptic neurons will keep sending impulses to our post-synaptic neuron, while it's refracted. What will happen to all these impulses? Will they just become "discarded" somehow? Or will they be still somehow accumulated within the post-synaptic neuron and their influence will be considered later, after neuron comes back to the resting state, in order to produce an action potential?

Because, if the incoming signals are discarded, then we are losing the "data" in some sense, which I don't believe is happening in reality. If these signals are accumulated somewhere, what's the maximum capacity of this "somewhere"? What happens in case of overflow? And anyway it would mean that the transfer of the signal within the network gets delayed, and that's quite confusing...

Here you are confounding the function of a neuron with its implementation (you might want to read about David Marr's 3 levels of analysis). Functionally you can describe neurons and neural networks using information theory, bayesian modelling, causal networks or any other framework makes sense in what you are studying. However keep in mind that a neuron is a biological object.

There are 2 kinds of refractory periods caused by 2 separate mechanisms (see image from physiologyweb.com). Firstly because the potassium channels are slower than the sodium channels, there is a time after the spike where the cell is hyperpolarized. The electrical potential of the neuron is lower than its resting potential. This is the relative refractory period where it is harder to make a neuron spike (because you need a higher depolarization to reach spiking threshold). This is well describe by the Hodgkin-Huxley model. On top of that the sodium channels themselves have a refractory period. After being activated they remain inactive until the cell become hyperpolarized. This is the absolute refractory period.

To go back to this idea of level of analysis, a model is always a simplification of the world. If you wanted to have an exact model of a neuron you would need to model the ions themselves. Instead if you are interested in the flow of ions you can simply model the gates and their dynamics. If you are interested in the electrical potential you can ignore the gates and use the Hodgkin-Huxley model. If you are interested in the spikes you can simplify it even further and use an intergrate-and-fire model. You can even model only the mean firing rate and so on and so forth. From the point of view of the neuron, or the ions being pumped in and out the neuron, there is no "data" to be processed. All you can say is that it functionally behaves as if it was implementing whatever function you are studying. But keep in mind it will always be imperfect as it is a biological object.


Is it possible to improve interoceptive awareness/accuracy? If so, how? For those unfamiliar, interoceptive awareness/accuracy involves awareness of, and sensitivity to, internal physiological sensations ("My heart is beating fast").  Interoceptive information is fundamental to how we conceptualize our affective experiences. For instance, people with high interoceptive sensitivity may be more likely to emphasize information about high/low arousal in their emotional self-reports (Barrett, Quigley, Bliss-Moreau, & Aronson, 2004).  Sensitivity and awareness of interoceptive information is fundamental to many other forms of cognition as well.

My question is whether we can improve people's interceptive awareness/accuracy with some sort of intervention (e.g., biofeedback) and whether this improvement might predict other adaptive outcomes.

Interoceptive awareness and accuracy
Interoceptive awareness and accuracy are sometimes used interchangeably, but can also refer to two different things: awareness to the tendency to attend to interoception measured by self-report, and accuracy to the actual accuracy with which one does so (Chentsova-Dutton and Dzokoto, 2014). For example, a cross-cultural study involving West African and European-American found that "West Africans showed higher levels of interoceptive awareness, but lower levels of interoceptive accuracy than European Americans" (Ceunen, Van Diest and Vlaeyen, 2013).
Heartbeat perception training
There have been some recent attempts to produce improvements in interoceptive awareness and accuracy. Schaefer, Egloff, Gerlach and Witthöft (2014) gave 29 patients with somatoform disorders heartbeat perception training, and reported that the training selectively improved interoceptive accuracy in patients with low health anxiety, as well as improvements in symptoms.
Mindfulness
Silverstein, Brown, Roth and Britton (2011) also found that mindfulness training produced a statistically significant benefit in speed of interoceptive awareness, and that this improvement was associated with improvements in attentional, self-judgmental, and clinical factors of female sexual dysfunction. They reported the following about increased interoceptive awareness:

Women who participated in the meditation training became significantly faster at registering their physiological responses (interoceptive awareness) to sexual stimuli compared with active controls (F(1,28) = 5.45, p = .03, $η_{p}^2$ = 0.15).

Another recent study of experienced meditation practitioners did not report a benefit of meditation on either interoceptive awareness or accuracy, however (Khalsa et al., 2008). Additionally, I am generally skeptical of the benefits of mindfulness on cognitive ability. See Jeromy's answer about the general effect of mindfulness on cognition.
References

Ceunen, E., Van Diest, I., & Vlaeyen, J. (2013). Accuracy and awareness of perception: related, yet distinct (commentary on Herbert et al., 2012). Biological psychology, 92(2), 423-427.
Chentsova-Dutton, Y. E., & Dzokoto, V. (2014). Listen to your heart: The cultural shaping of interoceptive awareness and accuracy. Emotion, 14(4), 666.
Khalsa, S. S., Rudrauf, D., Damasio, A. R., Davidson, R. J., Lutz, A., & Tranel, D. (2008). Interoceptive awareness in experienced meditators. Psychophysiology, 45(4), 671-677.
Schaefer, M., Egloff, B., Gerlach, A. L., & Witthöft, M. (2014). Improving heartbeat perception in patients with medically unexplained symptoms reduces symptom distress. Biological psychology, 101, 69-76.
Silverstein, R. G., Brown, A. C. H., Roth, H. D., & Britton, W. B. (2011). Effects of mindfulness training on body awareness to sexual stimuli: implications for female sexual dysfunction. Psychosomatic medicine, 73(9), 817.


Using CBT for a justified fear? I am a speech language pathologist. I have a 19 year old patient who grew up with a number of different speech impediments (not a stutter). He was bullied a lot, and because of this he is very sensitive about how he speaks.

Recently, he has become so anxious about it he has developed a stutter. Note that stuttering was not one of the impediments he grew up with. He only developed it a couple of months ago because of his anxiety. He is not in a financial position to afford a psychologist, so I decided to help him with his anxiety. I know I'm not in a position to get rid of his anxiety; thats outside my scope of practice - I'm only trying to help with the manifestation of his anxiety in his speech, which is within my scope.

He blocks completely - in other words, when trying to pronounce certain words, he becomes completely silent for a couple of seconds as he tries to "push" the word out. Rather than the usual case of repeating the same sound over and over again, he simply becomes silent while he waits for the word to come out.

His main fear is not being able to get the word out and just being completely silent while the other person is waiting for him to complete his sentence. This fear is quite justified unfortunately - most of us would be confused if a person just stopped talking and would ask him to continue. I've used CBT for a stutter before, but that was to show the patient that some of their fears (i.e. being laughed at) were irrational.

How do I address the anxiety that stems from a fear that is relatively justified and logical?

The first option is to investigate exactly what his worries are and to put them in perspective. Often, people catastrophize their fears, imagining the worst possible scenario for a given situation. While that outcome may be a realistic possibility, often is not the only or even the most likely possibility.
For instance, is he afraid that people will think he lacks intelligence? Or that people will laugh and make fun of him? You might examine his thought this way:

What is the worst possible outcome if he stutters or freezes in
front of another person?

What is the best possible outcome in the same situation?

What does he think is the most likely outcome? (Usually this is
somewhere in between the two extremes).

Second, you can caution him against mind-reading (i.e., assuming he knows what others will say, do or think). If he is concerned that when he freezes, "people will think I'm stupid," encourage him to think of other possibilities. They might think that, or they might just be confused, or they might recognize he's socially uncomfortable and have compassion.
Third, while the thought or fear itself may be true (e.g. "She made fun of me") the meaning he attaches to it might not be completely valid.
What does it say about him? For instance, if he thinks "She's right, I'm stupid, I'm a loser" you can explore all of his strengths and things he does well. Often people maximize painful experiences or don't give themselves credit for other accomplishments. Other thoughts, such as "This is something I struggle with, but I'm good at other things," might be more adaptive.
What does it say about that other person? You could work with him to reframe his thoughts (e.g. "She just doesn't understand and isn't sure how to react," or "That person has to be mean to others to make himself feel good; what he says isn't really true.")
What does it mean if someone reacts poorly when he freezes? If his thought is akin to "They'll think I'm stupid" figure out what it would mean in his life if they thought that way. How would that impact him? Is it "If I freeze, they'll think I'm stupid, and then I won't....get the job, make a friend, etc."? If you can figure out what consequences he is concerned about, then you can go back to option 1 and think through how likely those scenarios are.
Often fears and anxieties have some kernel of realistic risk to them. Some spiders or snakes can be dangerous, some people can judge us and be cruel, etc. However, if the fear is paralyzing, there is often a distortion to the thoughts that can be discussed and possibly adapted to reduce anxiety.
This book may provide additional ideas:
Beck, J. S. (2011). Cognitive behavior therapy: Basics and beyond. Guilford Press. (pgs. 1801-84 discuss some of the points mentioned above).


Is there a formal name for the "love" of arguing? Most of people drop discussion easily. Some others don't. As if they would like to argue.
They feel that they have to demonstrate something.

Is there a formal trait to describe people who enjoy arguing and the behavior of enjoying an argument?

I can't think of any clinical term for it, but a contentious individual is one who is eager to fight. Another term, pugnacious, is a little less derogatory than contentious.


Is there a psychometric tool for measuring the difficulty of mental activities? It is often stated that Alzheimer's disease can be prevented to some extent when a person engages more often in challenging mental activities (http://www.mayoclinic.org/diseases-conditions/alzheimers-disease/basics/risk-factors/con-20023871)

Although I can imagine that solving mathematical problems is more difficult than watching reality shows on TV, the criteria for this classification are vague to me (Ok not so vague because mathematics requires more cognitive load, but this may not be the only factor). I am interested in how could a psychometric scale that quantifies level of difficulty in a broad range of activities be constructed as it would be useful in research on prevention and rehabilitation of certain neurocognitive disorders.

Has such a scale been developed?

There is a workload measure called the NASA-TLX (Task Load Index), one component of which measures mental workload.  It is self-reported workload, however, and also requires interrupting most tasks, so it has some theoretical as well as practical weaknesses.

There is also decently good data that working memory load can be extracted from theta-band activity in the frontal regions, possibly due to the parieto-frontal circuits between the anterior cingulate, inferior frontal, and posterior parietal cortices.

(All of this, however, assumes that working memory load and "difficulty" are the same thing.)

Nasa-Task Load Index (NASA-TLX); 20 Years Later. Hart, S. (2006). Proceedings of the Human Factors and Ergonomics Society Annual Meeting October 2006 vol. 50 no. 9 904-908 doi: 10.1177/154193120605000909

Evidence for effects of task difficulty but not learning on neurophysiological variables associated with effort. Brouwer, A. & al. (2014). International Journal of Psychophysiology Volume 93, Issue 2, August 2014, Pages 242–252.
doi: 10.1016/j.ijpsycho.2014.05.004

Working memory load modulation of parieto-frontal connections: Evidence from dynamic causal modeling. Ma, L.; Steinberg, J.; Hasan, K.; Narayana, P.; Kramer, L.; et al. Human Brain Mapping 33.8 (Aug 2012): 1850-1867.
doi: 10.1002/hbm.21329


What are the effects of implanting electrodes into the brains of monkeys? If one implants electrodes into a monkey's brain in order to allow the monkey to control a mechanical arm, then is the monkeys able to move both it's natural and it's mechanical arms at once?

What happens if, say, the same signal might tell the mechanical arm to move up, and the natural arm to move down?

The interface between the brain and the hand is not like a USB computer port, and we don't unplug the biological arm and plug in a mechanical one instead. We implant electrodes to just a tiny fraction of the neurons in M1 (about a hundred, out of millions), and use their signals to control the mechanical arm.

So the answer is yes. The monkeys don't lose any dexterity in their biological arm because of the Brain-machine interface (BMI). Actually, during the BMI experiments, they usually move their biological arms all over the place. There is no reason why, after enough training, they couldn't control the mechanical arm almost completely independently of the biological arm and at the same time, like you control your digits (almost) independently.


Why do teenagers take the internet and cyberbullying so seriously? Background: I saw this post on the daily Mirror: A girl committed suicide because some users bullied her on ask.fm. I signed up to see what that site is, and it was some Q&A site. So she committed suicide just because someone bullied her, someone she doesn't know, maybe a bot!
That article said that many other teens did the same.

I'm broadly interested in why do teens in particular take the internet so seriously.
As Sherry Turkle said, we're connected but alone. And she said that the internet is all about sex, lies and avatars.

Questions

Why do teenagers take the Internet so seriously?
Is it because they are attached too much to the internet?
Are they trying to escape real life by building virtual worlds?
Is there any study research on this?

I would like to begin by saying this answer is based on my opinion. All the statements I make are conclusions I have drawn and may or may not have merit.

Firstly, it is unlikely the cyber bullying would be the main cause of someone to suicide. The underlying reasons for suicide run deeper than this.  I believe their problems ran far deeper than recent external events. Of course, bullying will not help a person in deep depression, and could assist in pushing someone close to the edge, however, I think the whole process behind someone committing suicide takes more thought and a deep level of depression (endogenous or otherwise).

It seems social networking and certainly the internet, has involved many people, of a varying age range.  From the conflicts that ensue all over the internet, it is not limited to teenagers.

  The fastest growing segment of social media users is now adults aged 45-54%.

The problem with teenagers, is they have less experience at handling their emotions and reactions (just by the mere fact of years of experience due to age alone), coupled with soaring hormone changes. Most would agree puberty and the ensuing years of a person's development are challenging for both the person and those around them.

This leaves the teenager as likely to be:
More impulsive.
More affected by others behaviour.

People who are "content" and occupied in their "real lives" do not seek to "build" and find solace in a "virtual" life.

I think cyber relationships serve many purposes and the dynamic of human interaction has developed, so that the group mentality is magnified. The anonymity and perceived (and in many ways real) freedom of consequence of user expression online has enabled a level of what (at least was until recently) socially unacceptable behaviour. A bravado and propensity for abuse that may not be present when two people are face to face in a local car park or shopping centre.

Having said that, the school playground can be a tough one, for ostracising children and bullying. I believe that face to face confrontations have a greater impact than those online.

I believe much of our emotional reactions to our online experience are charged with the emotion of our "real life" experience. Let's face it, we are communicating with faceless people. Psychologically this would be a less powerful experience. Another way of saying "Art imitating life".

Having said that,   a young person at higher risk of suicide, may well turn to the internet to find friends and support.

  Factors that increase the risk of suicide among teens include:

  lack of a support network, poor relationships with parents or peers, and feelings of social isolation

So, in conclusion:
 I don't believe teenagers are destroying their lives, whilst building virtual lives. (this was the title of the question when I posted my answer)

I believe that :

with real life trials
with the propensity within a young person for depression and
potential suicide
with the mitigating factors that may increase the likelihood for a person
to commit suicide
and the loosened boundaries found over the internet.

Our teenagers are in danger of being badly affected by their virtual lives.


Reference request: the necessity of constraints in learning I've read theoretical papers on why constraints are a necessary part of any learning system. The papers were aimed at human learning. I'm having trouble finding relevant references now.

What papers deal with the theoretical issue of whether or not learning must be constrained?

If that suffices, I can give you the classical article from the domain of language learning: Gold 1967.

The basic intuition is that an infinite number of grammars could explain any given set of strings. Analogously, you can probably consider fitting a polynomial to a set of points, or instances of the inverse problem (reconstructing a source from observations). In language acquisition, without some prior constraint on the to be acquired grammar, therefore, no unique convergence will happen. This has led to the Poverty of the Stimulus class of arguments, and the wide range of responses to it. There is a wide range of responses to the Gold paper - if you want more, it really depends on what specifically you're looking for.

In practice, I don't think anyone can imagine a learner in the real world that is without constraints, first and foremost those of storage and computational power.


What can be inferred about the strength of the synapse from an electron microscope image? In the following EM image (1um scale), there are several synapses:

Image or HD Version

What information about the synaptic strengths can be extracted from this image?

Does vesicle count contain information?
What about the cross sectional "length" of the synaptic cleft?
If serial sections were used to reconstruct a 3D version of a synapse, would the surface area of the synapse reflect the strength of the synapse?

Vesicle count and spine morphology are two of the better-known predictors of synaptic strength.  But they are not the whole story.

Glia, like astrocytes can also modulate synaptic strength by releasing their own neurotransmitter or co-agonist, but you need more than just images to detect that process.  There is also the matter of receptor distribution in the postsynaptic cell inside the synapse.  Even if you make more vesicles, it won't matter if there's not enough receptors.  It also depends on how much agonist, co-agonist, and antagonist are present, which could be the result of any particular molecular signaling cascade.  There are also modulators which can increase or decrease the effectiveness of a particular receptor.


Are cognitive biases hardwired in the brain or they are acquired during lifetime? The Kahneman–Tversky interpretation of biases as deviation from rationality was challenged by Gigerenzer on the basis that heuristics help making decisions and, thus, rational from the evolutionary point of view.

But are individuals born with significantly biased judgment as part of their genetic heritage or biases come mainly from early education and later experience?

Given a wide variety of issues implied in this question, maybe you can answer about some biases?

Addressing your first question (like @Josh, I would advice moving the other point to a new question), Morsanya & Handley (2008) (I can't find an open-access copy, sorry) have recently argued that heuristics have to be learned and acquired over time.
They presented a group of children aged 5 - 11 with several multiple-choice reasoning tasks, consisting of conjunction fallacy tasks, if-only fallacy tasks (concerning counterfactual reasoning), sunk cost fallacy tasks, and syllogistic reasoning, and found that as children got older, or scored more highly on an IQ test, they tended to provide more "heuristic" responses, and less "correct" ones.

They interpret this result as indicating that younger/less intelligent children aren't sophisticated enough to figure out the correct response, but haven't developed the heuristics either, so respond as random. As children become older/more intelligent, heuristics develop, but the children still haven't developed enough to produce the correct responses (bear in mind that with adults, more intelligent individuals produce more correct and less heuristic responses, so the trend reverses once people are advanced enough to figure out the correct response).

Reference

Kinga Morsanyi, Simon J. Handley, How smart do you need to be to get it wrong? The role of cognitive capacity in the development of heuristic-based judgment, Journal of Experimental Child Psychology, Volume 99, Issue 1, January 2008, Pages 18-36, ISSN 0022-0965,


Does limiting one's trivial decisions free more energy for bigger decisions? I've read a number of times that "successful" people limit the number of trivial decisions they make on a day-to-day basis in order to have more energy for bigger decisions. A common example cited (e.g., here) is Mark Zuckerberg wearing the same shirt every day, which saves some creative energy for the business decisions he needs to make.

Is there any scientific evidence for this?

Evidence on this question stems from research on ego depletion and the "Strength Model of Self Control" (Baumeister, Vohs, & Tice, 2007). The theory posits that successful self-control relies on a limited resource that is depleted by tasks requiring self control.

In series of experiments, Vohs and colleagues (2008) have investigated the hypothesis that, because making choices is mentally taxing, subsequent attempts to engage in self-regulation are more likely to fail.

Citing from their abstract:

  The current research tested the hypothesis that making many choices impairs subsequent self-control. Drawing from a limited-resource model of self-regulation and executive function, the authors hypothesized that decision making depletes the same resource used for self-control and active responding. In 4 laboratory studies, some participants made choices among consumer goods or college course options, whereas others thought about the same options without making choices. Making choices led to reduced self-control (i.e., less physical stamina, reduced persistence in the face of failure, more procrastination, and less quality and quantity of arithmetic calculations). A field study then found that reduced self-control was predicted by shoppers’ self-reported degree of previous active decision making. Further studies suggested that choosing is more depleting than merely deliberating and forming preferences about options and more depleting than implementing choices made by someone else and that anticipating the choice task as enjoyable can reduce the depleting effect for the first choices but not for many choices.

So judging from this research, if you stand in front of your wardrobe every morning and experience the decision between the black and the grey t-shirt as an arduous and mentally taxing choice exercise, it might indeed be better to always wear grey, as Mark Zuckerberg does.

It has to be said, however, that some people have doubted whether self-control can really be understood as a finite resource that can be depleted and favor a motivational account of the effects (e.g., Inzlicht, Schmeichel, & Macrae, 2014; Job, Dweck, & Walton, 2010).

Furthermore, the specific data about making decisions is only the result of one paper (I am not aware of independent replications, but they might exist) and, more generally, there are some doubts about how strong and reliable ego depletion effects are (see this earlier question).

In conclusion, it doesn't hurt to avoid complicated but trivial choices. Nevertheless, I would still hold on to those black shirts (my heuristic is to take the one that lies on top, by the way).

References

Baumeister, R. F., Vohs, K. D., & Tice, D. M. (2007). The strength model of self-control. Current Directions in Psychological Science, 16(6), 351–355. http://doi.org/10.1111/j.1467-8721.2007.00534.x

Inzlicht, M., Schmeichel, B. J., & Macrae, C. N. (2014). Why self-control seems (but may not be) limited. Trends in Cognitive Sciences, 18(3), 127–133. http://doi.org/10.1016/j.tics.2013.12.009

Job, V., Dweck, C. S., & Walton, G. M. (2010). Ego depletion--Is it all in your head?: implicit theories about willpower affect self-regulation. Psychological Science, 21(11), 1686–1693. http://doi.org/10.1177/0956797610384745

Vohs, K. D., Baumeister, R. F., Schmeichel, B. J., Twenge, J. M., Nelson, N. M., & Tice, D. M. (2008). Making choices impairs subsequent self-control: A limited-resource account of decision making, self-regulation, and active initiative. Journal of Personality and Social Psychology, 94(5), 883–898. http://doi.org/10.1037/0022-3514.94.5.883


Are neural adaptation and drug tolerance to psychoactive drugs related? Neural adaptation is "...a change over time in the responsiveness of the sensory system to a constant stimulus". The example given is placing your hand on the surface of a table. Eventually, you no longer sense your hand touching the table because your neurons have adapted to the stimulus.

Drug tolerance is "...reduced reaction to a drug following its repeated use". This means that increased dosages are required to produce the same effect. I've been careful to state that the drugs I'm considering are psychoactive drugs, so their mechanism of action of is mostly within the brain.

The missing link between these two concepts seems to be acclimatization. Acclimatization is "the process by which the nervous system fails to respond to a stimulus, as a result of the repeated stimulation of a transmission across a synapse".  The article on neural adaptation states that acclimatization is the process by which neural adaptation is usually believed to occur.

So is drug tolerance a form of neural adaption with the stimulus being whatever substance a subject repeatedly consumes? It's worth noticing that adaptation does not specify a direction of change in responsiveness. Therefore, assuming drug tolerance is a form of neural adaption, and if the effects of exposure to drugs become amplified rather than diminished, it too would be a form of neural adaptation.

Links to sources in order of appearance:

Neural adaptation

Drug tolerance

Acclimatization

Drug tolerance can be generally defined as

  A condition that occurs when the body gets used to a medicine so that either more medicine is needed or different medicine is needed.

Tolerance to drugs can be produced by several different mechanisms.

In the case of morphine or heroin, tolerance develops at the level of the cellular targets. Activation of opiate receptors triggers the inhibition of the enzyme adenylate cyclase. After repeated receptor activation, adenylate cyclase adapts so that the morphine can no longer cause changes in cell firing (source: NIH).

However, stating that a single target is involved is definitely an oversimplification.

Another NIH report on ethanol dependence gives an awesome comprehensive overview of the bewildering complexity behind this phenomenon, and I will only shortly sum up the different mechanisms stated there:

Functional Tolerance develops due to brain adaptations that compensate for the alcohol. Chronic heavy drinkers show few obvious signs of intoxication even at blood alcohol concentrations (BAC's) that would otherwise be considered fatal. Examples of functional tolerance are the following:
Acute tolerance can be observed within a single drinking session. Alcohol-induced impairment is greater when measured soon after beginning alcohol consumption than when measured later in the drinking session.
Environment-dependent tolerance develops over several drinking sessions and is accelerated if alcohol administration is always in the same environment, for instance in the local pub.
Learned tolerance develops by practicing a task while under the influence of alcohol. Rats develop tolerance faster in the context of maze walking when they have been when walking in a maze under influence for instance that practiced the task while under the influence of alcohol than rats practicing without prior alcohol administration. Likewise, people develop tolerance more rapidly if they practice a task while under influence, for instance on an eye-hand coordination task. w
Environment-independent tolerance needs larger doses.
Metabolic tolerance results from a more rapid elimination of alcohol from the body and is caused by the upregulation of liver enzymes that metabolize alcohol. Enzyme activation increases alcohol degradation and reduces the time during which alcohol is active in the body, thereby reducing the duration of alcohol's intoxicating effects.

The metabolic tolerance is the easiest to comprehend, but the environmentally-dependent tolerance and learned tolerance, for instance, are definitely centrally mediated, but not just by one simple molecular mechanism, but by the interplay of complex neural networks governing complete and complex associations and tasks.

Source
- National Institute on Alcohol Abuse and Alcoholism


Why are websites constantly updated even when the change seemingly reduces functionality? Examples:

Imagine coming to SE tomorrow and instead of seeing "1 2 3 4 5 ... 77 next" at the bottom of the "questions" page, you see a giant circle with a triangle inside pointing to the right and you no longer have the option of going from page 1 to page 5 in one click, but you must now click the big circle incrementally instead.
Or imagine your favorite weather website having a 10-day forecast horizontally across the screen like a calendar would have, then one day it changes to a vertical alignment because someone decided it was time for a change.

Questions:

Why do people do this?  And is it normal to feel extremely frustrated by this?  I mean, when something works well and makes sense, leave it alone?.  Why change stuff just to change stuff?  And especially when the change is less functional or intuitive.

1)  Split testing designs in marketing (this is partially related to Jeromy's first point):  You don't know which type of layout or content will accomplish the ultimate goal you want your potential customers or users to attain for you.  Thus, you test several different varieties, measure the difference in them, factor in statistical validity, and get a better site/page for your goals.  These litte improvements can mean the difference betwee, campaign (lets say for example a paid one) making you a negative return on your investment(s) or could cause it to make you a million dollars this year.  When there are so many people online, the margins are thin and any little advantage you have will, essentially, be your profit most of the time.

2)  They hired someone who is "specialist at UI design" and are paying them on salary.  The UI is already complete, so they have all this free time on their hands to do nothing.  So instead of looking completely useless to their boss/company they start making arbitrary and unnecessary updates to the website/webpage many of which may seem pointless and skewed within actual testing that is going on.  They do this so they can keep their UI design jobs, that is, unless they're legitimately trying to test things and know how to go about doing this in the correct way (most have no clue what they're doing besides making something that is aesthetically pleasing and which could be obtained by simply looking at the UI's of other popular softare).

3)  Different theories of search engine optimization for your website:  A large theory out there is that Google likes sites with freshly updated content and that it is usually a positive variable towards increasing your rankings.  Part of the thing about SEO is is looking natural as possible, if you were to update too much content too frequently there's a possibility that their algorithm may sense a red flag.  Noone really knows how this works though. Thus some people may even prewrite content updates and then just release them as time goes on.


Looking for references discussing aspect of human/animal adaptivity and its pertaining computational objectives Does anyone know some references (e.g. papers or book chapters) that discuss aspects of the adaptivity of human/animal based on studying the behavior and ideally, what computational objectives pertaining to the adaptivity of human/animal have been or can be suggested based on them?
An example: Animals should adapt to their environment to survive, they should develop whatever [computation] needed to detect the hunter and escape timely. They should update their internal model (whatever we define the internal model), with changes in their environment.

Dynamic systems analysis has recently made inroads into psychology.  Quirin et al.(2020) consider adaptive processes and may be a place for you to start.
Quirin, M., Robinson, M. D., Rauthmann, J. F., Kuhl, J., & Deyoung, C. G. (2020). The Dynamics of Personality Approach (DPA): Twenty Tenets for Uncovering the Causal Mechanisms of Personality. European Journal of Personality. https://doi.org/10.1002/per.2295


Have there been any studies into language development in the blind? The title pretty much says it all.  I'm looking for any studies or experiments into language development in those born blind.

I'm interested as part of my investigations into AI on how language is developed without visual cues and if language is impaired in anyway because of this and I've yet to come across any.  Has anyone heard of such an endeavor?

Yes, there have been a number of studies on language development in children with congenital profound visual impairment (PVI) over the years. Selma Fraiberg first described differences in early development, specifically later emergence of personal pronouns compared to typically sighted children [1].
More recent studies found that the vocabulary development of children with PVI follows a different trajectory. Vocabulary sizes is initially smaller compared to typically-sighted children, then develops rapidly and may surpass the vocabulary size of typically-sighted children of the same age [2]. Differences in the way that language is acquired in the early years, e.g. through shared gaze interaction with the caregiver, may part of the reason for the different developmental trajectories.

This is only a very superficial treatment of this question. There are entire books on this topic that offer a detailed discussion of the research:

Perez-Pereira, M., & Conti-Ramsden, G. (1999): Language development and social interaction in blind children. Hove, UK: Psychology Press/Taylor and Francis.

Pring (2004): Autism and blindness. Research and reflections. London: John Wiley & Sons.

[1] Fraiberg (1968): "Parallel and divergent patterns in blind and sighted infants" The Psychoanalytic Study of the Child, Vol 23, 1968, 264-300.
[2] McConachie & Moore (1994). "Early expressive language of severely visually impaired children" Developmental Medicine and Child Neurology, 36(3), 230–240.


Are there any definitions of the perception & JND of the colour of light approximately like how the Weber Law defines it for the brightness of light? As I understand it, the greater light levels are the more we require in order to detect a difference. I've also read this holds true for colour saturation. However, I can't seem to find any information that accounts for hue or the wavelength of light.

It depends how you define colors. Color-spaces are always 3D. The most obvious colorspace is based on the 3 types of cones you have (LMS) however it is not very sensible as you have no idea what your cones are. A slightly more sensible one is the CIE 1931 XYZ colorspace, which is a linear transformation of the LMS colorspace. One axis of this space was specifically chosen to match brightness perception. So if you take a plane orthogonal to this luminance axis you can define a point by 2 coordinates which can be (or not, again depending of what coordinate system you use) saturation (how far you are from neutral gray) and hue (the angle from neutral gray). You can measure thresholds, or Just Noticeable Differences (JNDs) around different points of this plane. Those are called McAdams ellipses (after the scientist who first performed this experiment). They look like this:

As you can see the size and orientation of these ellipses vary widely depending on where you are in this space. So it is not really true that Weber's law applies to color perception. Not to saturation and certainly not hue. At least not when you measure chromaticity in terms of physical units.

In facts in color perception the reasoning is somewhat inverted. What colorspace should you use, considering a physics-based colorspace, such as CIE XYZ, accounts so poorly for what we subjectively perceive? More recently different colorspaces have been designed that distort the XYZ colorspace non linearly such that these ellipses become more circular (e.g. the CIE Luv color-space). In that case whether Weber's law applies or not totally depends on how you defined you colorspace. But we know that Weber's law is a general law in perception and applies to all percepts such as motion, depth, you name it, and also more abstract percepts such as numbers. So it is sensible to design a color-space where saturation respects Weber's law. However for hue Weber's law is not meaningful, as it is an angle.

MacAdam, D. L. (1942). Visual sensitivities to color differences in daylight. Josa, 32(5), 247-274.

https://en.wikipedia.org/wiki/MacAdam_ellipse


Understanding neuronal firing in the context of Spike Timing Dependent Plasticity When discussing Spike Timing Dependent Plasticity in neurons, when we say that a neuron fires do we mean it fires only one spike? Or do we still say "the neuron has fired" when a train of n spikes was actually fired?

I find this detail a little confusing when we learn spike timing dependent plasticity (STDP), for example. If the neuron fires only one spike, then the time of firing is precise enough for relative timing between input and output signals to be well defined, and then the theory makes sense. Otherwise, one should give an approximation of the duration of the firing train of spikes and compare it with the duration of depolarization process in the dendrite that triggered this firing. But I can't find any of these anywhere.

Not sure I understand your question correctly.  What is it you can't find anywhere?  I would comment and ask for clarification, but that requires 50 rep which I don't have in this community.  Just tell me if my reply doesn't answer your question and I'll update.

There are two basic ways to describe neurons' firing.  One is rate-based and the other is spiking.
In rate-based neural networks, we look at the intensity, as it were, of a neuron's response to a certain input.
Within the framework of rate-based neural networks, we usually assign numbers to firing rates without attaching any units.
That is, in the model of a neural network, we may say that the response of a neuron has a firing rate of 0.8, but we don't specify 0.8 of what this is (spikes per second, per 10 seconds, per minute...), and it usually doesn't matter either, because all that is important is that it is more or less than the response of another neuron or to a different stimulus.
Note that this presumes that the rate is constant after the stimulus is presented.

In spiking neural networks, we model neurons' responses in much greater detail, designing differential equations which describe the time course of polarization and depolarization, such that a given depolarization can lead to explosive behavior which we call a 'spike'.

Now, many instances of neural information processing can be described very adequately using rate-based abstractions.
This is convenient, because rate-based ANN tend to be much more stable and computationally more efficient.
Also, biological neural firing can be measured much more easily in terms of intensity than in terms of spiking---especially for whole populations.
Therefore, we know more about many of the phenomena we try to model in terms of firing rates than in terms of timing, so rate-based neural networks actually capture our knowledge better.

Only in those cases where we have information about the precise timing of responses, and where we believe it to be important for the phenomena we try to model, does it make sense to accept the much more specific and difficult ontological commitments of spiking neural networks.
Otherwise, we understand what is happening in terms of intensity, not timing, and therefore the actual number of spikes per second do not matter.

The point is, 'firing' refers to related but very different concepts in the two abstractions of biological neurons, and they can't really be compared.
Either you talk about individual spikes in a spiking model, or you talk about rates of spiking over some non-descript unit of time in a rate-based ANN, but trying too hard to compare the two concepts will lead to confusing and nonsensical situations.