Variation in prefrontal cortex development I have read everywhere that the prefrontal cortex is not fully developed until about the mid twenties, but everyone's brain develops differently. Is it possible for a teens prefrontal cortex to be significantly more developed than it should be at this age?

In the last 20 years or so, a growing amount of neuroimaging research has demonstrated that adolescence is a period of continued brain growth and change, challenging longstanding assumptions that the brain was largely finished maturing by puberty (Giedd, et al. 1999; Sowell, et al. 1999; Sowell, et al. 2001; Johnson, et al. 2009).

Several major morphological and functional changes occur in the human brain during adolescence (Giedd, et al. 1999), and the maturation of the adolescent brain is influenced by (among other things) heredity, environment, nutritional status, sleep patterns, and sex hormones (estrogen, progesterone, and testosterone), which play a crucial role in myelination (Arain, et al. 2013).  Full development and maturation of the prefrontal cortex is generally believed to occur at roughly 25 years old, however, Sowell, et al. (2003) found a subtle increase in grey matter density until age 30, which remained stable until a steep decline in later decades.

  A detailed study is required in order to determine the exact biomarkers involved, as well as the intricate influence of diet, drugs, sex, and sleep on the maturation of the adolescent brain as discussed briefly in this report (Arain, et al. 2013).

Despite the fact that brain development may be done by our 30s, it doesn’t mean that someone with a fully developed brain cannot change it. There is considerable evidence to suggest that we can still change our own brains with a process called neuroplasticity. Our brains are constantly adapting to our environment, experiences, and other inputs to which it is exposed.

References

Arain, M., Haque, M., Johal, L., Mathur, P., Nel, W., Rais, A., ... & Sharma, S. (2013). Maturation of the adolescent brain. Neuropsychiatric disease and treatment, 9, 449.DOI: 10.2147/NDT.S39776 PMCID: PMC3621648 PMID: 23579318PDF: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3621648/pdf/ndt-9-449.pdf

Giedd, J. N., Blumenthal, J., Jeffries, N. O., Castellanos, F. X., Liu, H., Zijdenbos, A., ... & Rapoport, J. L. (1999). Brain development during childhood and adolescence: a longitudinal MRI study. Nature neuroscience, 2(10), 861.DOI: 10.1038/13158 PMID: 10491603PDF: https://web.stanford.edu/class/cs379c/archive/2013/suggested_reading_list/supplements/documents/GieddetalNN-99.pdf

Johnson, S. B., Blum, R. W., & Giedd, J. N. (2009). Adolescent maturity and the brain: the promise and pitfalls of neuroscience research in adolescent health policy. Journal of Adolescent Health, 45(3), 216-221.DOI: 10.1016/j.jadohealth.2009.05.016 PMCID: PMC2892678 PMID: 19699416PDF: https://www.jahonline.org/article/S1054-139X(09)00251-1/pdf

Sowell, E. R., Thompson, P. M., Holmes, C. J., Jernigan, T. L., & Toga, A. W. (1999). In vivo evidence for post-adolescent brain maturation in frontal and striatal regions. Nature neuroscience, 2(10), 859.DOI: 10.1038/13154 PMID: 10491602PDF: https://cloudfront.escholarship.org/dist/prd/content/qt1d34r7w2/qt1d34r7w2.pdf

Sowell, E. R., Thompson, P. M., Tessner, K. D., & Toga, A. W. (2001). Mapping continued brain growth and gray matter density reduction in dorsal frontal cortex: Inverse relationships during postadolescent brain maturation. Journal of Neuroscience, 21(22), 8819-8829.DOI: 10.1523/JNEUROSCI.21-22-08819.2001 PMID: 11698594 PDF: http://www.jneurosci.org/content/jneuro/21/22/8819.full.pdf

Sowell, E. R., Peterson, B. S., Thompson, P. M., Welcome, S. E., Henkenius, A. L., & Toga, A. W. (2003). Mapping cortical change across the human life span. Nature neuroscience, 6(3), 309-315.DOI: 10.1038/nn1008 PDF: https://www.researchgate.net/profile/Paul_Thompson13/publication/10933611_Mapping_cortical_change_across_the_lifespan/links/564f004408aeafc2aab33ed0.pdf


Is it possible to bridge implicit and explicit memory? It is self evident, from the various studies of Skinner and Pavlov, that a traumatic - or one of a similar nature - experience possesses the tendency to reside within certain schemas through the processes of classical conditioning; exmpli gratia, one may experience unpleasant stings from a wasp ,and thusly bestow fear ( based on that of the pain derived from stings) upon all creatures with similar characteristics through generalisation. And, hence these conditions based upon the creatures may last for prolonged durations, depending upon the frequency and "intensity" of the exposure.

However, my question is: could there possibly be a way to bridge implicit memory with declarative in such a process similar to conditioning? So that, as one, for instance, endeavours to memorise a speech, a certain experience associated , despite the fact that the speech may have never encountered the memoriser, could massively boost one's ability to do so.

I acknowledge the fact this question may not only seem far-fetched and implausible but perhaps spawned from ignorance, yet, I am invariably pondering upon ways to increase one's memory a part from the traditional mnemonics and other strategies.

Is it possible to 'bridge' implicit and explicit memory?

Short answer: It does not make sense to talk about 'bridging' implicit and explicit memory.

Longer answer: Explicitness and implicitness of memory is most appropriately considered a property of the memory test, not the memory being tested. Memories, physically speaking, have both explicit and implicit properties. They are 'bridged' by default.

The difference between explicit (and more specifically declarative) memory and implicit memory is more definitional and epistemic, i.e., related to our ability to measure and analyze, than anything empirical. Memory is declarative, by definition, when it can be tested by way of an articulated participant response. Memory is implicit, by definition, when it can be tested by way of behavioral performance.

For example, consider something basic like transporting yourself from point A (say, your house) to point B (say, the train station). You have implicit memory of this route, which we can see by observing you move from A to B. You also have explicit memory of this route, which we can see by having you describe the path from A to B. It is fundamentally no more complex than that.


How does the brain physically get tired? When engaging in physical work-outs, people often research how regular muscles store energy, how to eat and exercise cleverly so that the exercises actually make them stronger and more healthy instead of making them constantly tired or even sick.

Where can I find similar explanations, but for brain, that would explain and describe how brain, as an organ, gets exhausted and what is the proper/recommended discipline for using brain as an organ the most effectively? (e.g. how should study sessions get scheduled, what should be included into the diet, what activities should be possibly avoided,etc)

The first rule of Neuroscience Club is to check your Kandel.

The second rule of Neuroscience Club is to check your Kandel.

Joking aside, the gold standard of neuroscience is Kandel et al.'s Principles of Neural Science, currently in its fifth edition. It's an extremely (and in the cognitive sciences, I would say uniquely) comprehensive and authoritative work, and you can certainly use it to find an explanation for your questions about how the brain stores and uses energy, or virtually anything else. It's that rare kind of book which successfully distills a massive subject down to something as simple as possible, and no simpler than that.

  Kandel, E. R., Schwartz, J. H., & Jessell, T. M., Siegelbaum, S. A., Hudspeth, A. J. (Eds.). (2013). Principles of neural science (Vol. 5). New York: McGraw-Hill.

It does not really make sense to talk about "how to use the brain as an organ most effectively." The brain is only metaphorically similar to muscles, and only in certain respects. One of the relevant differences is that neurons do many things and often exhibit nonlinear behavior, whereas muscles more or less only stretch and contract. This currently makes it very difficult to scientifically define what optimizing brain function means, exactly, compared to defining what optimizing muscle function means.

I will not deconstruct the question further since it is primarily a reference request, and this will all be more than clear from Principles of Neural Science.


What practical dysfunctionality characterizes severe autism? I have only known one autistic person and as far as I could see he was perfectly functional except that he could not relate to other people. It seemed as though most of the stuff his parents and others were trying to get him to do were not things that he actually needed to do, but were various forms of human ceremony, like looking people in the eyes and other things like that which have no practical necessity, but are just societal norms.
The main practical failure I saw in him was an inability to convey complex plans or ideas to other people.
So, I am curious what genuine functional disabilities severely autistic people have, as opposed to social misbehaviors. As far as I could tell, by reading complaints of parents of autistic children, the only true dysfunctionality I could detect were the following:

Ignoring traffic, walking into moving traffic without looking
Failure to discriminate between potentially dangerous strangers and friends
Failure to recognize dangerous objects like knives
Increased propensity to enter bodies of water and drown

Now, of course, all children suffer from the above dysfunctions, and it appears that autistic children simply are more likely to endanger themselves. Does this tendency to be unaware of these dangers continue into adulthood, or do adults with autism learn to respect water and other dangers the same way non-autistic adults do?

Autism is an extremely broad and multidimensional set of difficulties. 2 severely autistic person does not necessarily have the exactly same set of difficulties. There are various psychometric tests and questionnaries (Related link: How do we measure autism severity) for measuring severety of autism, but you may call it a total or overall measurement of difficulty. The exact set of difficulties vary from one autistic individual to another.
If you’ve met one person with autism, you’ve met one person with autism.
If 2 person shows symptoms of autism severely that does not mean the 2 person will show the each symptom with same severety. Their areas of strengths, deficits, sensitivities etc. can be entirely different.
The functioning labels  indicate how much support an autistic person needs, with level 1 meaning relatively little support is required and level 3 indicating the need for a great deal of support.
Update:

So, I am curious what genuine functional disabilities severely
autistic people have, as opposed to social misbehaviors

I am afraid why social dysfunctions are "not genuine" one. The social misbehaviours come from some cognitive problems, such as context blindness, prosopagnosia, etc.

Ignoring traffic, walking into moving traffic without looking Failure
to discriminate between potentially dangerous strangers and friends
Failure to recognize dangerous objects like knives Increased
propensity to enter bodies of water and drown

Sounds like severe intellectual disability, an often overlapping condition with autism. Severe autism certainly means severe impairment in some aspects of cognition, but not necessarily all aspects of cognition and intellect, and may have advance or even gigantic ( Autistic savants ) intellect in specific areas of cognition.

The main practical failure I saw in him was an inability to convey
complex plans or ideas to other people.

Similar other failures the autistics may experience, are prosopagnosia, dyscalculia, dyslexia, dyspraxia, issues with sensory processing (including meltdowns and shutdowns), problems with processing multiple sensory inputs, working memory problems, and many other. Autistics also may face anxiety and confusion with unpredictability or sudden changes in a plan or routine, These problems are very practical, serious and debilitating.


How to compute Chi-square value and degrees of freedom in Excel? I am trying to understand the statistical test of the chi-square in Excel. I already made the test but I still don't know how to compute the χ² value and what it means, how to compute the degrees of freedom and how to write a propper APA approved result section. Can anyone help me and explain this in a simple way?

I have a population of n=76. 'Left' = 25 and 'Right' = 51. The hypothesis is you would expect a normal distribution ('Left' =38 and 'Right' = 38). So the question is 'is this distribution a coincidence?' The p < .029. By seeing this outcome I thought there is that is no coincidence that there isn't a normal distribution and it must be due to a variable.

Is it true in this case the degress of freedom is just n-1?

This is really more of a statistical question (except perhaps the bit about APA style). As such it probably belongs on stats.stackexchange.com .

A binary variable does not have a "normal distribution". A normal distribution is bell shaped and is relevant to continuous data.

Your null hypothesis is that the population proportions for left and right handers are equal. Thus, if your chi-square value is sufficiently large, then you might reject the null hypothesis and conclude that the population proportions are unequal.

If $k$ is the number of categories (you have two categories), then
degrees of freedom for the one sample chi-square test is $k-1$ (i.e., $2-1 = 1$).

To calculate chi-square check out the example here.

The following formula in Excel should give you a p-value. For example if your chi-square value was 22, and your degrees of freedom was 3:

 =1-CHISQ.DIST(22, 3,TRUE)

the first argument is the chi-square value
The second argument is the degrees of freedom
The third argument indicates that a cumulative distribution (CDF) is desired
Thus by taking 1 minus the value of the CDF you get the probability of getting a chi-square value as large or larger than the observed value.

You can check your formula by looking at existing calculated tables.
http://home.comcast.net/~sharov/PopEcol/tables/chisq.html


Simultaneous extracellular recording from different distant sites (in rodents) I wonder whether it is technically possible today to have simultaneous extracellular recording in awake rodents (e.g., mice) from different non-proximate sites (e.g., V1 and frontal cortex). I mean to have two or more different electrode penetrations at the same time. Using multi-array / grid / tetrode  it is possible record from many locations, but they are spatially proximate. Any references are appreciated.

I wouldn't know why multi-site cortical extracellular recordings would not be feasible? What would the practical experimental or technical limitation be in your opinion?

As long as you have a multichannel amplifier suitable for extracellular recording and you consider the choice between using a common reference, i.e., monopolar recordings (Ludwig et al., 2009), or using paired recording-reference electrodes for bipolar measurements (Boatman-Reich et al., 2010) you should be fine.

References
- Boatman-Reich et al., Front Comput Neurosci (2010)
- Ludwig et al., J Neurophysiol (2009); 101(3): 1679–89


Paper showing that completing most psychological studies is less distressing than daily life I once read a study that compared the level of distress of completing a psychological study to other activities in daily life (e.g., commuting to work; interacting with colleagues; watching tv; or something like that).

The paper is a good reference when you are applying for ethics approval.

Does anyone know the reference?
Or perhaps there are a few such articles?

The article could be

How distressing is it to participate in medical research? A calibration study using an everyday events questionnaire.

Petrie, K. J., Faasse, K., Notman, T. A., & O'Carroll, R. (2013).
JRSM short reports, 4, 1-7.

PDF available


What is the psychological explanation for the phenomena that a person sees the solution to a problem as “simple” once it has been found? Is there in psychology an explanation and/or term that describes the phenomena that exists where people perceive a solution to a problem as “simple” after the solution has been found?
I have noticed in my many years of working with people that there are some who claim the solution to a problem was “simple” - and take great pride in this - but only after the solution has been found.
Of course, many things seem “simple” or “obvious” after they are known.

Example:  Fixing a car.

A mechanic needs to fix a car the problem area of which he does not know “specifically” but “generally” and he has to test each part he removes.  The parts are A, B, C, D and E. He has to remove parts B, C, D and E just to get to part A, all of which are time-consuming to remove (except part A).  Part A turns out to be the faulty part and it’s easy to replace - just two screws.
The boss (who is a mechanic himself but with higher rank within the company) says that the repair was “simple” - just had to change part A.

(Think an electrical system issue - battery, alternator, starter, starter relay).

Is that “oversimplification bias”?  I don’t know if such a bias exists.

As @Arnon suggested in the comments, this looks to be a case of the hindsight bias, especially given the reference to "hindsight is 20/20" in a comment.

Via Wikipedia:

  Hindsight bias, also known as the knew-it-all-along phenomenon[1] or creeping determinism,[2] refers to the common tendency for people to perceive events that have already occurred as having been more predictable than they actually were before the events took place.[3][4] As a result, people often believe, after an event has occurred, that they would have predicted, or perhaps even would have known with a high degree of certainty, what the outcome of the event would have been, before the event occurred.


Have IQ-type measures been tried for other animals? Despite the obvious difficulties pertaining to definition and measurement, and the various controversies surrounding the use of IQ-type scores in human beings, it seems unquestionable that there are significant intraspecies individual differences in some general component of learning ability.
Have any such measures in fact been defined and investigated for any non-human species?

Like any simple-seeming cognitive sciences question, it is important to start with a series of disclaimers. It might seem like human intelligence or intelligence more generally is an intuitive concept, but once you start to explore your intuition or look at historic definitions of intelligence, you see that intelligence is a very ill-defined and slippery concept. You could, of course, take the behaviorist view, and define intelligence as performance on IQ-tests, and then your question has a simple answer: no, we can't measure that in most animals.
Alternatively, you might try to look at general behaviors that you usually associate with intelligence, then you can often come up with tests for animals. However, this might challenge some of your preconceptions. I want to provide two example tests (but many many more exist) to illustrate my point.
When we usually think of 'intelligence' we are eager to associate things like behavioral flexibility and innovation with it. Both of these can be tested.
Serial discrimination reversal learning
Serial discrimination reversal learning is a relatively standard procedure for studying animal cognition. The first reference I can find to this specific methodology is from 1966 in the sea lion (Schusterman, 1966), but the basic ideas of using similar tests in animals was already common practice before WW2 (Spence, 1936).
The task is usually given in the form of a choice between two actions (say pushing a button). At first whenever the animal clicks the left button, it is given a treat, and nothing for the right button. This training phase is continued until the animal learns that left button gives food. At this point, the reversal phase is enacted, and suddenly the left button stops giving food, and the right button does, and the animal is trained to associate the right button with food.
These learning, reversal, learning cycles are repeated several times and the rate of change from one button to the other after reversal, and consistency of picking the correct button during learning are tracked to give a measure of the animals behavioral flexibility. There is great inter-species variation on this, but also a lot of intra-species variation.
Innovation tasks
Innovation tasks are popular in the context of social learning, where the animal (and the species) has to balance between innovating and copying behavior (Reader & Laland, 2003). The classic example of this is English greats tits learning to break the foil caps of home-delivered milk bottles to eat the cream at the top (Hawkins, 1950).
An example I want to highlight is from Griffin et al. (2013), where myna birds where tested with a novel extractive foraging task. In this task, birds faced difficult foraging tasks like having to pull out a piece of paper from a champagne flute before getting food, or by having to open a dish with a lid that could only be lifted by a hook in the middle and not from the side. Birds show great interspecies and intraspecies diversity on these sort of innovation tasks.
Challenging preconceptions
Naively, one might expect both reversal learning and innovation to be important components of intelligence, and 'smarter' animals to do better on both. This intuition would be well supported if you looked at the inter-species level, you would find an increase in innovation and behavioral flexibility with relative brain size. However, at the intra-species level, Griffin et al. (2013) show that this is not necessarily the case. Among myna birds, those that do better on the innovation task, tend to perform worse on the reversal learning, and those that do worse on the innovation task, tend to perform better on the reversal learning. This means that if you are looking for variation within a species, then you have to be careful with your tests. Two tests that both correspond to an intuitive notion of "intelligence" in humans, might in fact correspond to opposite ends of the spectrum in the non-human animal.
References
Griffin, A. S., Guez, D., Lermite, F., & Patience, M. (2013). Tracking Changing Environments: Innovators Are Fast, but Not Flexible Learners. PloS One, 8(12), e84907.
Hawkins, T. (1950). Opening of Milk Bottles By Birds. Nature 165(4194): 435–436.
Lefebvre, L. (2011). Taxonomic counts of cognition in the wild. Biol. Lett. 7: 631–633.
Reader, S.M. & Laland, K.N. (2003). Animal Innovation. Oxford: Oxford University Press.
Schusterman, R.J. (1966) Serial discrimination-reversal learning with and without errors by the California sea lion. J. Exp. Anal. Behav. 9: 593–600.
Spence, K. W. (1936). The nature of discrimination learning in animals. Psych. Rev,, 43(5): 427.


Study on likability, weakness, and competence? I heard a podcast about a study (I think it was Radiolab or similar) that found that people are viewed as more likable after they reveal a weakness or a shortcoming, but the effect only occurs if they have established that they are competent.

What is that study? The podcast said it is influential and well known.

In the podcast, a professor told a story about how when he was a graduate student made a fool of himself in front of his PhD advisor and he joked that he did it on purpose to improve his likebility and she retorted that he hadn't yet established himself as competent. I remember hearing it in late 2014. Any help enormously appreciated!

Thank you all for your responses. I found the answer independently - I was looking for the Pratfall Effect described in Elliot Aronson's 1966 paper "The effect of a pratfall on increasing interpersonal attractiveness" in Psychonomic Science.

The paper's abstract reads:

  An experiment was performed which demonstrated that the attractiveness
  of a superior person is enhanced if he commits a clumsy blunder; the
  same blunder tends to decrease the the attractiveness of a mediocre
  person. We predicted these results by conjecturing that a superior
  person may be viewed as superhuman and, therefore, distant; a blunder
  tends to humanize him and, consequently, increases his attractiveness.

More information on the Pratfall Effect can be found here: Wikipedia, Psychology Archive

Aronson, E., Willerman, B., & Floyd, J. (1966). The effect of a pratfall on increasing interpersonal attractiveness. Psychonomic Science, 4(6), 227-228.


Do social classes hang more with the same social class? Do social classes hang more with the same social class?

Further, how "reasonable" phenomenon this is?

If we take "social class" to mean income/wealth as it's most commonly the case in the West today, then there's even an academic term for the uncommon friendships across such classes, namely "income-bridging". As for their occurence, let me quote you from a paper by Léna Pellandini-Simányi (which happens to survey Hungarian society, but I think it easily generalizable across the Western world):

  Many of the income-bridging friendships are between former classmates whose class position diverged, yet who kept
  their old friendship alive.

Let me tell you from personal experience that this is 100% the case for me, if we take the "income-bridging" to mean a tenfold difference in income.

Also from the same paper on Hungary, this interesting bit regarding the socialist past:

  During socialism, status-bridging friendships were not more frequent in
  Hungary than in capitalist societies, contrary to the image of an egalitarian and open society promoted by political public discourse. [... However] It is important to note that these [socialist-era] studies measured class by education and working position, omitting income.

The last part kinda reminds me of joke/advice along the lines of: don't get a PhD to impress your friends, once you get a PhD most of your friends will have one.


Do beavers make dams purely by instinct? Do beavers use cognitive moves, learning, memory or skill acquisition in their life to build better? Or do they simply repeat instinctive gestures and end up with stereotyped architecture always?

It seems that running water triggers some sort of instinct:
http://juneauempire.com/stories/050408/out_275269543.shtml


What is the difference between Symbolism and Abstract thinking in Piaget's Theory? I'm having trouble understanding the difference between symbols and abstract thinking in Piaget's Cognitive Development Theory. Piaget says that in the preoperational stage, children 2-7 years old can think of things in terms of symbols, and that abstract thinking forms in the formal operational stage. I thought symbols are a part of abstract thinking, perhaps because symbols, to me, seem abstract. So, what does the theory mean when it refers to "abstract thinking?" Can someone give me a concrete example delineating the difference between the abstract thinking and symbolism parts in their respective stages? Much thanks!

Symbolism uses a symbol to represent an existing object, while abstract thinking can be thought of as considering things that don't actually exist.

For a rough example of each, consider representation as symbolism (this paper is the plane I'm on) and consider generalization as abstraction (what it means to be "on" something). For another, consider something (this blue line on a paper) that represents something else (this river), contrasted with considering the concepts of "blue" or "line".


Why do we long for freedom? Psychological reactance is the effect of irrational choice for freedom - we choose to go for a greater loss just because we like to make the bad decision for ourselves. What is the advantage behind that?

Too lazy to paraphrase right now, so quoting from a newsletter

  Brehm [the guy how introduced the notion Psychological Reactance--my note] has made but one remark about why people seem to behave as his theory describes. He wrote that the reactance-emotion may have “survival-value” (Brehm 1966, p. 1-2). This explanation seems quite plausible. People and other organisms who are frequently in situations in which they can choose between different behavior alternatives are likely to have evolved a capacity for choosing what is most often best for their fitness. Moreover, creating, defending and restoring situations in which the individual is free to make a choice may in itself enhance fitness. Therefore, natural selection probably favored individuals who not only perceive when their freedom is threatened, but also act so as to defend that freedom. Brehm has described the psychological mechanism by which people (and probably many other species) are motivated to defend their freedom. That is, the attractiveness of behaviors varies with the freedom an individual perceives to possess.

As with most evolutionary hypotheses of behavior, it's probably hard to test.

I tried to find papers on animal models of reactance, but (unlike say for learned helplessness) there don't seem to be any. A recent review doesn't mention any such models either. It does however say some things that contradict your assumption that's just a negative outcome:

  reactance can produce both undesirable and desirable outcomes. It has been found, for example, that the experience of reactance can elicit heightened achievement motivation (Steindl & Jonas, 2014). Recent studies have also shown that the experience of reactance can be associated not just with negative feelings, such as anger, but also with activating positive affect, such as feeling strong and determined (Steindl, Jonas, et al., 2015). We invite future research to investigate the desirable motivational side of reactance in order to make use of its energizing probabilities.


When was statistics used in psychology research first? I am wondering about the origin of statistics' usage in psychology. Psychology was rooted in philosophy. At that time there were no experiments and analysing the data, but I guess that there must be the very first time when someone came up with the idea to use statistics in the analysis. (and that's my question).

This paper suggests it was a psychophysics experiment by Fencher in 1860.


Binary classification as a cognitive strategy? Is there any research investigating whether the human cognitive system has a tendency to reduce complex systems or spectra of data in terms of binary contrast?

There are many common-sense dual taxonomical sets. Some of these have a basis in objective reality (the binary male/female has proved an especially effective evolutionary strategy), others may be argued to be more in the eye of the beholder. Day and night could be said to be extremes in a cycle; left and right, conservative and liberal are ranges on a spectrum (cf. friend and foe; "there are only two kinds of people"). A lot has been written about gender identity and sexual orientation in the framework of a Hegelian master/slave dialectic, but I am not interested in the relationship between the members in an oppositional set. Structuralist theorists and anthropologists have claimed and then disclaimed that societies organize themselves in binary sets, but more interesting to me than factual organization is how reality is perceived. Also, when an anthropologist or theorist says most concepts are defined by contrast with their opposites, I can't help but wonder whether we have quantifiable data along these lines.

I am hoping to find out whether these common-sense binary taxonomies correlate with cognitive/perceptive processes. Especially interesting to me is the question whether there are certain low-level cognitive strategies, though I am also interested in high-level processes (e.g. formal logic is mostly organized along binary lines, true/false). Since the cognitive sciences are not my field, I would be very grateful for references to both foundational studies and "raw" field work. General works on the reduction of reality to accommodate limited processing power are also welcome. Visual processes are not my primary interest, but if you can point to a single "best primer" on the filter that allows us to "see" an entire bookcase but not all book titles in a single glance, that would be a helpful bonus. I know nothing about the workings of biological neural networks, but if there is a binary selection at any point in their operation, I would be very grateful to see that explained in an accessible but peer-reviewed text. Finally, keywords to help me find more on this in scholarship search engines would be most helpful.

I think there is a misperception at work in your question. There is a wide variety of objects that we never perceive in such a binary manner: colors, fruit (apples, oranges, plums, ...), weather, and basically every other concrete objects. The only things we perceive in a binary fashion are abstract ideas! Good versus evil. Liberal versus conservative. And here we can ask about the reality (which is more complex) and the function of this simplification. The answer is: speed of decision making.

The basic binary classification is negation: x versus not x. The usefulness of this distinction becomes apparent when you put it in context: Is this berry edible or not? Do I want to trust this person or not? All binary opposites have a negation at their basis and divide the world into things you want to avoid and things you want to interact with.

And since human beings have to decide about one million things every day, they make life easier by using heuristics to make most of these decisions: simple rules based on experience, so you don't have to think before you vote for your next president.

The few binaries that are more or less objective, are categories of measurement: long/short, hot/cold, bright/dark, etc. That the physical reality underlying these measurements is maybe more complex (e.g. coldness depends not only on temperature, but also on the humidity of the air and the speed of the wind), is not relevant to the one-dimensionality of our sensation.

Night and day is not binary, since we have dawn and dusk and late afternoon and early morning and the dead of night as well to differentiate subjective time, relative visibility, quality of light, restedness/tiredness etc., that all make up the meaning of "night", "day" and other daytime names. The phrase "day and night" is binary only in certain phrases where they have symbolic meaning (e.g. "day" = good, "night" = evil, or "working night and day" = working all the time, without resting).

Studying the development of thinking styles in college students, Perry (1970) found that as they grow their thinking advances from a dualistic black-and-white perspective to a multiplicity of truths that allows for uncertainty. They also grow from a purely intellectual to an ethical perspective. In the course of this development, dualistic thinking can serve as an alternative to forward progression, and persons that already have developed to a higher level of thinking can use dualistic thinking as a "retreat" (Zang, 2002): "a student returns to a dualistic orientation to find security and the strength to cope with an overchallenging environment".

Binary thinking is related to personality disorders such as borderline personality and narcissism (Oshio, 2012): "The results indicated that thinking dichotomously may lead to
wide-ranging personality disorders."

Sources:

Oshio, A. (2012). An all‐or‐nothing thinking turns into darkness: Relations between dichotomous thinking and personality disorders. Japanese Psychological Research, 54(4), 424-429. doi:10.1111/j.1468-5884.2012.00515.x
Perry, W. G. (1970). Forms of intellectual and ethical development in the college years: A scheme. New York: Holt, Rinehart and Winston.
Zhang, L. F. (2002). Thinking styles and cognitive development. The Journal of Genetic Psychology, 163(2), 179-195.


What's the difference between the neuroendocrine system vs endocrine system? No one in the Biology site seems to be answering this, so I thought I'd post it here as a last resort. I would really appreciate if you guys can take a look at it.

This is what I have understood so far:
Neuroendocrine system involves neuroendocrine cells (also known as neurosecretory cells) that receive nerve impulses by a sensory neuron to release neurohormones into the blood stream. Meanwhile, the endocrine system endocrine cells that release your 'classic' hormones into the blood stream when a receptor protein senses a stimulus.

Here are my questions. You don't have to answer them in order, you can just provide an summary explanation:

When it comes to the brain, are the neurosecretory cells located in
the hypothalamus or the posterior pituitary gland or both?
Is the hypothalamus and the posterior pituitary gland classified as
    neuroendocrine glands and is the anterior pituitary classified as an
    endocrine gland?
If the posterior pituitary gland is indeed a neuroendocrine gland,
    is ADH and Oxytocin, which are both released by the posterior
    pituitary gland, classified as "neurohormones", not just the classic
    hormones?

Neuroendocrine systems can be defined as the sets of neurons, glands and non-endocrine tissues, and the neurochemicals, hormones, and humoral signals they produce and receive, that function in an integrated manner to collectively regulate a physiological or behavioral state.
The neuroendocrine system is the mechanism by which the hypothalamus maintains homeostasis, regulating reproduction, metabolism, eating and drinking behaviour, energy utilization, osmolarity and blood pressure. (Source)

The central neuroendocrine systems serve as an interface between the brain and many of the peripheral endocrine systems. This chapter discusses the hypothalamic control of anterior pituitary systems regulating stress, basal metabolism, growth, reproduction, and lactation. Each of these systems involves one or more hypothalamic releasing or inhibiting hormones, released from hypothalamic neurons that terminate in the portal capillary vasculature that projects from the median eminence at the base of the hypothalamus to the anterior pituitary gland. There, the hypothalamic hormones act upon subsets of anterior pituitary cells to regulate pituitary hormone release and downstream physiological functions. Other hypothalamic neuroendocrine cells control water/salt balance, and lactation/parturition, through the release of vasopressin and oxytocin from nerve terminals that arise in hypothalamus and project to the posterior pituitary gland. Together, these hypothalamic neuroendocrine functions enable the central nervous system to respond rapidly to internal or external environmental change, and to maintain a response through endocrine hormonal transducers. (Gore, 2013).

The endocrine system is a group of glands and other structures that release internal secretions called hormones into the circulatory system.

Endocrine organs are richly vascularized ductless organs that produce hormones. The epithelial cells of the organ secrete their hormone product directly into the bloodstream where, upon binding with specific receptors in target organs, cellular functions are affected. The endocrine systemincludes not only the endocrine glands (pineal, pituitary, thyroid, parathyroid, and adrenal) but also single cells and small clusters of cells in the thorax and abdomen known as paraganglia. This chapter addresses the thyroid, parathyroid, adrenal, pituitary and pineal glands, and paraganglia. In addition to size differences, several features of endocrine tissues differ between rodents and humans, and often between rodents. (La Perle & Dintzis, 2018).

Question 1

When it comes to the brain, are the neurosecretory cells located in the hypothalamus or the posterior pituitary gland or both?

Neurosecretory cells are found in the hypothalamus. (Source)

There are two types of neurosecretory cells: magnocellular cells and parvocellular cells. Magnocellular cellsare large cells, having long axons that terminate in the neurohypophysis (also known as the posterior pituitary). Magnocellular cells release the hormones vasopressin and oxytocin to the general circulation; we will talk about the physiology of these hormones in Conjoint 403.  The parvocellular cells are small cells, with shorter axons that terminate at a capillary-rich bulge at the base of the hypothalamus known as the median eminence.

Question 2

Is the hypothalamus and the posterior pituitary gland classified as neuroendocrine glands...

No

...and is the anterior pituitary classified as an endocrine gland?

Yes.
The following is from: https://courses.lumenlearning.com/boundless-ap/chapter/the-pituitary-gland
(emphasis mine)

The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system. Despite its name, the posterior pituitary gland is not a true gland; rather, it is largely a collection of axonal projections from the hypothalamus that terminate behind the anterior pituitary gland.

The pituitary gland is an endocrine gland, about the size of a pea, that sits in a small, bony cavity at the base of the brain whose secretions control the other endocrine glands and influence growth, metabolism, and maturation.
While the pituitary gland is known as the master endocrine gland, both of its lobes are under the control of the hypothalamus: the anterior pituitary receives its signals from the parvocellular neurons, and the posterior pituitary receives its signals from the magnocellular neurons.
The anterior pituitary, also called the adenohypophysis, is a major organ of the endocrine system, and is the glandular, anterior lobe of the pituitary gland.
The anterior pituitary gland secretes 7 hormones: follicle stimulating hormone, luteinizing horomone, adrenocorticotropic horomone, thyroid stimulating horomone, prolactin, endorphins, and growth hormone.
The posterior pituitary gland does not synthesize any hormones.  Hormones known as posterior pituitary hormones are synthesized by the hypothalamus, and include oxytocin and antidiuretic hormone (ADH), also called arginine vasopressin or vasopressin (Liu, 2007). The hormones are then stored in neurosecretory vesicles (Herring bodies) before being secreted by the posterior pituitary into the bloodstream.
With regard to neurohormones mentioned in question 3, neurohormones are hormones that are produced by neurosecretory cells and released by nerve impulses (e.g., norepinephrine, oxytocin, vasopressin).
This is the part which can be confusing. Whilst ADH and oxytocin are released from the posterior pituitary gland, which is an endocrine gland, the hormones are produced by neurosecretory cells within the hypothalamus and they are stored in and released from neurosecretory vesicles within the posterior pituitary gland. Therefore they are classed as neurohormones.
References
Gore, A. C. (2013). Neuroendocrine systems. In Fundamental Neuroscience (Fourth Edition) (pp. 799-817). doi: 10.1016/B978-0-12-385870-2.00038-X
La Perle, K. M. D., & Dintzis, S. M. (2018). Endocrine system. In Comparative Anatomy and Histology (pp. 251-273). Academic Press. doi: 10.1016/B978-0-12-415759-0.00058-3
Liu, K. D. (2007). Hyponatremia and Hypernatremia. In Critical Care Secrets (Fourth Edition) (pp. 285-290). doi: 10.1016/B978-1-4160-3206-9.10044-8


Which R packages have good collections of psychology datasets? The open source statistical software R has a range of contributed packages. Some of them include datasets.

I teach research methods in psychology and I'm looking for interesting real-world dataset to use as the basis for tutorials. I've found a few in contributed R packages (e.g., AER, psych), but I'm not aware of a general resource listing R packages that supply multiple interesting, real-world, psychological datasets. In particular, some textbooks have an aligned R package containing many interesting datasets.

What R packages include multiple interesting, real-world, psychological datasets?
For any package identified, it would be good to have a sense of the kinds of datasets contained

Some extremely large personality data sets can be downloaded at http://personality-testing.info/_rawdata/ in CSV format.

They are not packaged in R, but I post the link because you indicate in your reply to USER:what that you are having trouble finding any data sets what so ever.


Terror management theory: Is this a valid conclusion based on the conducted experiment? I am currently reading the book ‘The Worm at the Core: On the Role of Death in Life’. I have to say that I am a bit skeptical about many of the statements posed, and I’m trying to identify why that is, so I decided to dive into some of the articles they reference.

One of the things I encountered was a reference to a paper by Schimel et al. (2007): "Is Death Really the Worm at the Core? Converging Evidence That Worldview Threat Increases Death-Thought Accessibility." In Study 5, they state:

  The results of Study 5 demonstrate, once again, that exposure to
  worldview-threatening information causes thoughts of death to become
  more accessible

They base this on an experiment in which they compare the DTA (death-thought accesibility) in three groups:

creationist/anti-creation, creationists who read anti-creation material (n=20, M=2.75)
evolutionist/anti-creation, evolutionists who read anti-creation material (n=20, M=1.95)
creationist/control, creationists who read neutral material (n=20, M=1.90)

I have trouble to see the validity of the conclusion based on the experiment. Might it not also just be the case that creationists in general think more about death? And that reading a passage about the theory of evolution (which is inherently about life and death), makes everyone, regardless of their point of view on evolution, think more about death? I think the problem with this experiment is that there is a group missing in the experiment; the evolutionist/control group. It might be very well possible that this group has a DTA of 0.95 and a low SD. If that were the case, reading the passage has increased the DTA of both the creationists and the evolutionists and thus nothing can be said about the effect of worldview-threatening information. All we would then conclude, is that reading about evolution increases DTA.

I am not a researcher myself, nor am I very familiar with social sciences. I hope someone with more experience in these fields could explain to me if my train of thought is correct, or if not, where the fallacy in this train of thought is.

I would also be interested to find references to articles that contain experiments that substantiate the statement cited above.

Solomon, S., Greenberg, J., & Pyszczynski, T. (2015). The worm at the core: On the role of death in life. Random House.
Schimel, J., Hayes, J., Williams, T., & Jahrig, J. (2007). Is death really the worm at the core? Converging evidence that worldview threat increases death-thought accessibility. Journal of personality and social psychology, 92(5), 789. (Free PDF)

Interestingly, the authors appear to have been aware of your concern:

  Given that the only difference between these groups involved a subject
  variable for which there could be preexisting differences in DTA, we
  included a third group of creationists who read a nonthreatening
  essay.

Since the evolutionist/anti-creation and creationist/control groups had very similar scores, there was seemingly no reason to suspect different baselines.  However, I agree with you that adding this third group may not have been sufficient to eliminate the potential for preexisting differences in DTA.

Dispositional DTA:

The study of preexisting differences in DTA baselines is relatively recent, and is called dispositional DTA.  This line of research is indeed showing significant variation in DTA between different groups in control conditions, variation in reaction to primes, and even variation in reaction to delay - see Mikulincer & Florian (2000) for examples of all 3.  So in light of this, I would not take it for granted that evolutionists and creationists should necessarily have the same dispositions.

Curiously, a study by Friedman and Rholes (2009) found religious fundamentalism to be negatively correlated with dispositional DTA (ie, greater fundamentalism = reduced effects on DTA).  Although fundamentalism is not the same measure as creationism, it does suggest that evolutionists may even have higher dispositional DTAs.

Ultimately however, a (not independent) partial replication of Study 5 is reported in Hayes (2011) Study 4, in which pro-evolution participants are subjected to an anti-evolution prime or the same control material used in Study 5, and the same DTA measure is used immediately thereafter.  While not having the creationist contrast, this experiment measures the evolutionists/control baseline missing from Study 5, as well as the effect of anti-evolution material on evolutionists.  I do note that the criteria for selecting participants was slightly different than Study 5, but not substantially different (n=93).

  DTA was higher in the Threat condition (M = 2.26, SD = 0.98) than in
  the Control condition (M = 1.68, SD = 0.96).

The results seem to indicate that the authors' assumptions about evolutionists' preexisting DTA may be valid.

Implicit primes:

The alternative explanation that reading about evolution might raise DTA in all participants due to the nature of the topic does not fit well within the context of existing DTA research.  Explicit primes increase DTA only after a delay or distraction.  For the immediate effects on DTA found in Study 5, an implicit prime must be used - ie, one that does not directly elicit thoughts of death.  This is presumably what Studies 1-4 establish.  Also see Steinman & Updegraff (2015) for a comprehensive review on the effects of explicit vs implicit primes on the need for delay.

In that context, had Study 5 not included evolutionists at all, the data gathered would have still been sufficient to conclude that reading about evolution increases DTA in creationists, substantiating the statement cited in your question.  The study's novel inclusion of a group with an opposing worldview adds some valuable information from which to consider additional conclusions.  That said, it would not be prudent in any case to make strong conclusions from a single, small, poorly controlled, unreplicated experiment.  In my view, this study has many flaws that I won't rant about here.  All I will say is:

Good on you for checking references, that is rare and commendable.
Good on you for applying critical thinking and questioning conclusions.

Re further references, the DTA hypothesis Wikipedia article contains many references to literature both supporting the cited statement and questioning the evidence for it.  Lots more on Google of course.


What article reported variability in supporting hypotheses across disciplines? I recently read a blog post talking about a journal article that compared the degree to which journal articles support their hypothesis. A comparison was done across disciplines, and if I recall, psychology had a higher level of acceptance than many other disciplines.

Does anyone know the reference to this article about variability in supporting hypotheses in journal articles across disciplines?

Fanelli D (2010) “Positive” Results Increase Down the Hierarchy of the Sciences. PLoS ONE 5(4): e10068. doi:10.1371/journal.pone.0010068

http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0010068


Is there any reason why chunking the digit span test would not help Is there any reason why chunking the digit span test would not help, and what is the average score without chunking? By chunking I mean any rehearsal besides saying the numbers one time as they appear.

I asked a similar question already:

Does the digit span test draw on any executive functions besides working memory, if "chunking" is not used?

Just intrigued why chunking might not work as well (and it's trivial that it won't always work as well), or not at all.

As far as I know the effectiveness of chunking depends on (1) test speed and (2) amount of practice.

At low speed simple techniquest benefit almost everyone a little, even with virtually no practice. Quoting from Dempster and Zinkgraf

  Recently, in fact, evidence has been found that questions the validity of the assumption
  that chunking plays a role in digit-span variance. In one experiment,
  Lyon (1977) presented 12-item digit sequences to adult subjects for whom conventional
  digit-span estimates were available, and instructed them to think of each
  successive group of three digits as a three-digit number. The important result was
  that subjects with high spans (average = 8.3) benefited just as much from the chunking
  instructions as those with low spans (average = 6.1). Thus, prompting all subjects to
  impose a common structure on the lists did not produce the convergence of the two
  groups that would be expected if chunking was the source of differences between
  subjects in the high- and low-span groups.

On the other hand

  However, it does seem plausible that the temporal characteristics of
  the digit-span task (rapid presentation rate and single trial) simply allow little opportunity
  for chunking, unless the individual is exceptionally adept at creating
  chunks (Hunt & Love, 1972, pp. 248-250), or has received an extended period of
  practice (Ericsson, Chase, & Faloon, 1980; Gates & Taylor, 1925; Martin &
  Fernberger, 1929). For such an individual, chunking can be a highly successful
  strategy.

The "extended practice" mentioned there involves associative techniques not merely chunking.


How does Kohlberg's moral reasoning work, can I measure it myself? Is there any way I can work out what stage Kohlberg would claim I was operating at?

I do refer, when thinking about what is best, permissible, etc., to laws and other people's opinions, punishment etc., but not as conclusive judgments on what is right or wrong etc., only as one aspect of how to try to make that judgment myself. And while my actual judgments I would claim apply to anyone, not just myself, they are also provisional, and subject to revision, reappraisal.

With some exceptions:

My happiness is often more valuable than other's, maybe just because I'm especially well set to work on that. Likewise I wouldn't be obliged to martyr myself for any reason, e.g. to save a million lives, though I would say the same of anyone. And certain actions are always and unequivocally wrong, for anyone, they are that heinous.

I think enough and loosely enough about morality to say that I'm probably post conventional, and perhaps that's all that really does matter. But I wondered if I could learn more!

That can't be answered with one particular stage because:

  Another criticism of Kohlberg’s theory is that people frequently demonstrate significant inconsistency in their moral judgements.[26] This often occurs in moral dilemmas involving drinking and driving and business situations where participants have been shown to reason at a subpar stage, typically using more self-interest driven reasoning (i.e. stage two) than authority and social order obedience driven reasoning (i.e. stage four).[26][27] Kohlberg’s theory is generally considered to be incompatible with inconsistencies in moral reasoning. [...]  Krebs and Denton have also attempted to modify Kohlberg’s theory to account for a multitude of conflicting findings, but eventually concluded that the theory is not equipped to take into consideration how most individuals make moral decisions in their everyday lives.

Having said that Wikipedia also mentions that some tests have been developed based on Kohlberg’s theory anyway, e.g. DIT (presumably averaging reasoning over a number questions), so you could try to take some of those tests.

As far as I can tell from their description(s), the DIT tests only involve abstractly reasoning about some scenarios that don't involve sellf-interest of the test-taker, so they don't quite seem to address the criticism, and they probably won't capture your exceptions in that area either, e.g "My happiness is often more valuable than other's". Krebs and Denton found that self-serving bias affects most people when it comes to moral judgements:

  Self-serving biases. In contrast to the third-person moral judgments
  evoked by Kohlberg’s test, most real-life moral judgments are made in the first person and second person. As examples,
  people say such things as “I was wrong; I should never have done
  that” and “You should do your share.” Krebs and Laird (1998)
  found that first-person moral judgments made by participants
  about transgressions they had committed were significantly more
  lenient than the third-person judgments they made about transgressions
  committed by others, especially when others’ transgressions
  were committed against them


How can I find open access journals for cognitive science research? What open access journals that publish research in cognitive science/psychology exist?

Apart from PLOS ONE, are there any other open access journals that publish research in cognitive science/psychology?

Where should I start looking for them?

The Directory of Open Access Journals is a great place to start when searching for Open Access Journals in any field.

You can browse through journals for the specific subject areas like Psychology or Neurology, or you can search for journals or articles containing certain keywords.

The DOAJ lists articles in multiple languages as well, not just English journals.


Is there a term for a person who moves from one field of expertise to a new field and has an inflated belief in their competence in the new field? Person A has led a successful career and is very well renowned in field A.
Later in life, person A moves to field B, a field they're curious about but have very little experience in.

Person A struggles to accept their limited understanding of their new domain, having been an expert in their own domain for so long, and imposes their (usually) incorrect views on a field B topic on others based on a confidence they've built from being good in field A.

Is there a term in psychology for this phenomenon?

Déformation professionnelle is probably the closest match:

  Déformation professionnelle is a French phrase, meaning a tendency to look at things from the point of view of one's own profession rather than from a broader perspective. It is often translated as "professional deformation" or "job conditioning". The implication is that professional training, and its related socialization, often result in a distortion of the way one views the world.[1]

Followed by the law of the instrument / Maslow's hammer:

  The concept known as the law of the instrument, Maslow's hammer, Gavel or a golden hammer[a] is an over-reliance on a familiar tool; as Abraham Maslow said in 1966, "I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail."[1]

References
1 [déformation professionelle]. Bönisch, J. (2007, November 30). Déformation professionnelle: Beruflich bedingte Missbildung. Süddeutsche Zeitung. Retrieved from http://www.sueddeutsche.de/karriere/deformation-professionnelle-beruflich-bedingte-missbildung-1.786888.
1 [law of the instrument]. Maslow, A. H. (1966/2004). The psychology of science (pp. 15). Maurice Bassett.


Can neuron change from excitatory to inhibitory (and vice versa) over time? According to this answer a neuron can release only specific type of neurotransmitters at the time, however, could it change over time? For example a neuron that now releases only inhibitory neurotransmitters, after a few days will turn into a neuron releasing only excitatory neurotransmitters. If it is possible, then what does it depend on (mathematical models appreciated)?

As far as I know, it is not possible for a neuron to change which type of neurotransmitter it releases.  However, it is the case that the neurotransmitter GABA changes from excitatory to inhibitory over the course of development.  This is occurs because GABA activates Cl- (chloride) channels.  The chloride concentration gradient across the cell membrane changes directions over development, so the direction of current caused by opening of Cl- channels also changes.

Nature Reviews Neuroscience 3, 728-739 (September 2002) | doi:10.1038/nrn920
Excitatory actions of gaba during development: the nature of the nurture
Yehezkel Ben-Ari
http://www.nature.com/nrn/journal/v3/n9/abs/nrn920.html


Predisposition toward organizing information in a hierarchical manner? I understand someone why we like hierarchical social structures today.  They are present across virtually all cultures and we've used them for a very long time.

However, it appears we also gravitate toward organizing things in hierarchies as well, not just people.  When we study topics, we draw diagrams of hierarchies.  When we write textbooks, we subdivide information into ranges of topics and them smaller ranges, and then the individual concepts themselves.  We put our paperwork in folders, in filing cabinets, which are arranged in shelves, which are arranged in rows of shelves, and so on...

Recently we've spent more time exploring other structures like networks with nodes, but our default still seems to be hierarchies.

It's not just organizations and governments that we organize this way, but also information.  Why is this?

Regarding the utility of hierarchies in organization information, binary search trees in computer science allow finding indexed information very quickly (Adamchik, 2009).  However it is common knowledge that we have been organizing information hierarchically long before the advent of computer science.  So did we realize this intuitively?

Perhaps this predisposition bleeds over in some way from social hierarchies?  Could our other predisposition to see human intention in inanimate objects have led us to use the same structure for information (Coolidge, 2016)?

References

Adamchik, V. S. (2009) Binary Trees. Retrieved from: https://www.cs.cmu.edu/~adamchik/15-121/lectures/Trees/trees.html

Coolidge, F. L. (2016). Why People See Faces When There Are None: Pareidolia. Psychology Today. Retrieved from: https://www.psychologytoday.com/us/blog/how-think-neandertal/201608/why-people-see-faces-when-there-are-none-pareidolia

This is not out of desire, it is out of necessity of abiding a feature of information and knowledge itself. Quite frankly, this goes into a bit of data science and information theory (I personally learned of this through data visualization. Nonetheless, I still think it is a relevant question).

According to Richard Wurman in his book, Information Anxiety, “information may be infinite, however… the organization [or structuring] of information is finite.” Furthermore, “Each vantage point, each mode of organization will create a new structure. And each new structure will enable you to see a different meaning, acting as a new method of classification from which the whole can be grasped and understood.”

The three main ways of organizing information are as follows (please note that those within parenthesis are my personal examples, the rest are more main/established ones):

Location
Categorical
a. (similarity/relatedness)
b. (problem/solution)
c. (cause/effect)
Hierarchical
a. Alphabetical
b. Time
c. (deductive/inductive order)
d. (importance)
e. (simplicity/complexity)

In relevance to hierarchical information and psychology though, it is worthwhile to note that both foundations of language and logic are found through the alphabetical category. These, in turn, are fundamental features of the human mind and are, in large part, also means through which the mind makes connections. Also, tendencies towards hierarchical information could also be explained through using time as an anchor to which to describe things in relation to such as the past, present, and future.


Can prosopagnostic (face-blind) people draw other people recognizably? Is it possible for people with face blindness / prosopagnosia to draw other people (whose faces they cannot recognize) such that non-face-blind people can recognize the people being drawn ?

According to Bruce & Young model (1986), face recognition is composed of 2 main sub-processes, one more "perceptive" (called structural encoding) and the other one more "associative" (fru, pin, name generation). Bruce & Young model

A person with "apperceptive prosopagnosia" cannot create a precise percept, that is a mental representation of who he's looking at. He's unlikely to be able to draw other people face.

A person with "associative prosopagnosia" can create a percept of who he sees, but he cannot understand who the person is, deficit is semantic not perceptive. In this case, he is able to draw other people face, even though he cannot recognize it.

This subdivision can be found also in object recognition process and its related impairments: apperceptive agnosia and associative agnosia.

It's important to note that all this stuff is heavily theoretical. Reality is much more complex and sometimes unclear.

Bruce, V., & Young, A. (1986). Understanding face recognition. British journal of psychology, 77(3), 305-327.


Is V1 involved in visual imagery? It's well known that mental imagery shares the neural substrates of its respective modality, despite dissociable multivariate patterns.  For example, visual imagery can be decoded across the ventral visual stream, but can be separated from vision-proper based on spatiotemporal dynamics.

However, there seems to be some controversy about the whether the "earliest" sensory regions (e.g., V1) are involved in mental imagery. To my knowledge, many studies seem to show either nonsignificant, weak, or marginal involvement of V1 in visual imagery, but some theoretical articles seem to suggest the opposite.

Can anyone shed some light on the current thinking/evidence?

Short answer
V1 can be recruited for visual imagery, but it is not strictly needed for imagery to occur, and it is not sufficient in itself to allow for visual imagery.

Background
Visual imagery is a complex and broad topic of research. It's in fact a big pain in visual prosthetic research. In this area of research it's often nice to show those fancy pics of deafferented visual areas in the brain to light up after having been deprived of visual activation for years. Then you find those seemingly strikingly activated visual regions by your awesome visual prosthetic, to be shot to pieces later by critical referees that believe it may just as well be that your subjects have been imagining stuff.

Anyway, visual imagery depends on much of the same structures in the visual system as seeing by itself. The retina, being considered part of the central nervous system, and the end organ of the visual system is not involved as it only delivers input by sensing light. Hence the optic nerve is not involved either. After that we have the brain stem and strikingly, already the LGN in the brain stem has been shown to be activated by imagery. And not surprisingly then, V1, being the output location of the LGN, is activated too (Chen et al., 1998).

However, activation of these regions does not mean they are necessary for imagery to occur. Because imagery follows the visual neural path pretty much in reverse, it is the higher association areas in the brain that are most crucial for this process to occur. Indeed, visual imagery has been shown to occur in people with large trauma-related defects in V1 nearly obliterating the occipital cortex (Bridge et al. (2012).

Meta analyses of various studies has delivered a potential reconciliation of these opposing findings. V1 recruitment may depend on the specific type of imagery, and specifically that detailed imagery is more dependent on V1 (Ganis, 2012).

References
- Bridge et al., J Neurol (2012) 259: 1062–70
- Chen et al., Neuroreport (1998); 16(16): 3669-74
- Ganis, Visual Mental Imagery, Springer Link (2012)
- Urbanski et al. Frontiers Integr Neurosci (2014); 8:74

Fig. 1. Visual system. source: Urbanski et al. (2014)


Difference between Psychology & Neuroscience in lay man terms? I am electronics engineer by profession
But i am confused in difference between Psychology & Neuroscience? Please explain in lay man terms?

A lot of neuroscience has nothing to do with the brain (never mind the human brain). For example research to regrow peripheral neuron or neurons in the spinal cord to help paralyzed individuals would be neuroscience but not psychology.

In the limit all of psychology is related to neuroscience, since if we could model individual neurons, networks, and brains, then we could predict all of human and animal behavior. That is still a long way off so I think it is reasonable to say parts of psychology are unrelated to neuroscience (e.g., social psychology and psychometrics).


Why do dual N-back games use certain letters? Every implementation of dual n-back that I've ever seen uses the set of letters 'C', 'H', 'K', 'L', 'Q', 'S', 'R' and 'T'.

Why is that?

The set is not always the one you suggest. There are many implementations that don't even involve letters, but use random shapes, numbers, spatial locations, or other stimuli.

In Jaeggi et al., 2007, they used spatial locations for the visual task, and

  The auditory material consisted of eight German consonants (c, g, h, k, p, q, t, and w) spoken in a female voice and selected on the basis of their distinctiveness.

(emphasis mine).

In Takeuchi et al. 2010, they used numbers and locations:

  “Dual” N-back task. In this task, the number stimuli consisted of numbers, 1 to 4, presented in a random sequence in one of four places on a line.


Neurological explanation for differences in what motivates runners? I have noticed differences between how my friends and I are motivated with regards to exercise, and would like to better understand what is influencing this difference psychologically.

Personally, I am indifferent to running events.  I have run for its own sake on my own, both at novice and intermediate levels; training myself until I could run 5k or 10k regularly.  I once did a half marathon distance on my own simply as I was curious whether I could do it.  I feel absolutely no motivation to run as part of a group, nor do I feel any motivation to run for the reward of getting a time or rank or medal or what have you.

However, I recognise that this mindset is unusual when compared to my friends.  One friend started running with a "couch to 5k" group, another is keen to train for a half marathon event, another is a semi-professional athlete, etc.  The point is that most people I know who run seem to be motivated differently.

What explains the difference between these types of motivation?  This is not to ask what drives motivation generally, but specifically what is the neurological and thus psychological root cause for individuals being motivated by different sorts of things, in this case about why people run as a form of exercise.

Your question is really broad and can encompass libraries. However, to add my 2-cents worth regarding

  specifically what is the [...] psychological root cause for individuals being motivated by different sorts of things...

I would say that a lot of this has to do with external factors, and specifically external sources promoting exercise to be 'healthy', including peer pressure and multimedia.

To pin this global effect on our way of thinking down to

  [the] specific[...] neurological root

is not really feasible in a single answer in theSE framework, as it is just way too complex to grasp on a single web page in a Q&A forum I'm afraid. But the between-subject differences can, at least partly, be explained by intersubject environmental differences.

Reference
- Brody & Inoue, Issues Innov Nursing Practice, 218-27


How can I find literature about the connection between proprioception and thinking? This is a seek for hints or references. Feel free to delete the question if it is not suitable to the rules in here.

I have heard people saying that our inner spacial perception is an important foundation for our ability to think. So if we are standing upright, the mere awareness that our hands "are below our head" and "our feet are below our hands", all orientation like this is more important for our thinking than it would seem first.

Further I have heard that there exists some sort of illness or disability, where the proprioception is somehow distorted or blocked, and this allegedly is affecting the thinking power. People who could think, calculate, conclude etc in a normal way, cannot do so any longer because their spacial perception/proprioception is somehow reduced.

A prominent person who is a counter example for this connection between proprioception and thinking could be Stephen Hawking. A prominent pro argument for the connection could be the process of training pilots in a centrifuge, thinking while suffering a lot of G.

My question is:

  Can somebody tell me the right terms or keywords so that I can find
  literature about the mentioned connection? My search shows very wide
  results between mathematical concepts, mental mapping, spacial
  orientation and more, but I am looking for the basic relation between
  muscles, nerves, proprioception and clear conceptional thinking.
  Or does somebody even now a paper which examines this connection?

Two major terms:

"Spatial Representation":

of pitch height (lower/higher):

https://www.sciencedirect.com/science/article/pii/S0010027705000260

emotions (down/up):

https://www.tandfonline.com/doi/abs/10.1080/02699930500347794

"Spatial Analogy":
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5256459/

Some papers argue that even time has strong spatial representation in it:
https://www.sciencedirect.com/science/article/pii/S001002770700087X


In the theory of planned behaviour, what is the general term that captures attitudes, norms and perceived behavioural control? The theory of planned behaviour is a model of behaviour that in simple terms assumes that attitudes, norms, and perceived behavioural control influence intention, and intention and actual control influence behavior.

I'm writing a paper that includes a measures of personality and a measure of the theory of planned behaviour. I sometimes need to refer to the variables attitudes, norms, and perceived behavioural control as a set. In particular, I often need to distinguish these variables from the personality variables. However, it typically seems a bit verbose to have to say "attitudes, norms, and perceived behavioural control" all the time.

Question:

What is a general word or short phrase to capture attitudes, norms, and perceived behavioural control?
Update: Even if it is better to generally refer to the three variables individually, what term describes this set of variables or what makes them distinct from other kinds of psychological variables like personality, intention, etc.?

McFarland and Ryan (2006) have an article applying the theory of planned behaviour to job applicant faking behaviour.

They use phrases:

"components of beliefs that influence intention"
"attitudes, subjective norms, and PBC"; i.e., they abbreviate perceived behavioural control (PBC) to make the phrase shorter
"the TPB predicts the intention to fake"; i.e., they use the "theory of planned behaviour" as a proxy for "attitudes, subjective norms, and PBC". Technically, the TPB is a theory that describes relationships between a set of variables. So this may work, but it is not using TPB as a proxy for attitudes, subjective norms, and PBC.
"beliefs": as in "relationship between beliefs and the intention to fake". This is a slightly simplification of the TPB. Attitudes are not just beliefs, but when presented in context, this seems clear.
"antecedents of intention": as in "relationship between antecedents of intentions and intention to fake". Presumably this works in contexts where the only predictors of intentions are attitudes, subjective norms, and PBC, but doesn't work if you have other types of antecedents.

Courneya et al (1999) have an article on personality, theory of planned behaviour and exercise behaviour. They refer to the TPB variables as:

"social-cognitive constructs"

References

Courneya, K. S., Bobick, T. M., & Schinke, R. J. (1999). Does the theory of planned behavior mediate the relation between personality and exercise behavior?. Basic and Applied Social Psychology, 21(4), 317-324.


What is the primary source of the "mount stupid" graphic? Online descriptions of the Dunning-Kruger effect are often accompanied by a "mount stupid" graphic similar to the below - from a Psychology Today article:

However, the research paper does not contain this graphic.  Here are some of the graphics from the original 1999 paper:

These graphics bare little resemblance to the ones found online - having no "mount stupid" in evidence.  The online images vary widely in their presentation, so if there is a primary source, then it would be good to know which one is the correct graphic, or if they are all fake.

[][]7

Similar images are used on some posts in this forum:

What is the term of having a high perceived confidence while having limited knowledge?
Quantifying the Dunning-Kruger Effect

Short answer
The cartoon graphics showing mount stupid seem to be exaggerated, popular-scientific representations, and should, as far as I can see, be regarded as schematics to illustrate a more subtle effect.

Background
From what I can find, the cartoons you provide are exaggerated and simplified versions depicting the more pronounced examples of the Dunning-Kruger effect like in Fig. 1 where subjects performed a Wason task (Schlösser et al., 2013). The mountain is somewhat visible here, especially in panel B where the raw scores are plotted. There the subjective performance increases monotonically, while the perceived score in the poorest quartile is above the second, which resembles the peak you are referring to. However, this is one of the most pronounced samples I could find and it may well be caused by variance, as other graphs in that same paper, other sources you provide above (Kruger & Dunning, 1999) don't show this peak. Similarly, plots in Dunning (2011) are less pronounced at this point.

Fig. 1. Actual versus perceived performance on Wason task. Dotted line represents where perceived performance should lay according to the Krajč–Ortmann model. source: (Schlösser et al., 2013)

References
- Dunning, Advances Exp Soc Psych (2011); 44: 247-96
- Kruger & Dunning, J Personality Social Psych (1999); 77(6): 121-34
- Schlösser et al., J Economic Psych (2013); 39: 85-100


How effective are pharmaceutical or therapeutic treatments for jealousy? This is the last of a series of questions I've posted about jealousy (see here, here, and here).

What pharmaceutical and therapeutic treatments, if any, have been developed for managing acute jealousy
How effective are these treatments?

Pharmaceutical:
Well, I can tell you there are no pharmaceutical treatments you can take that JUST help you manage "acute jealousy."  Essentially, any drug you would take that may help wouldn't just target "jealousy."  If there even is one that helps you to manage it it will have a global effect and probably be something like an SSRI, SNRI, amphetamine, some other drug that is probably going to end up making you feel worse in the long run.
Pharmaceutical wise, I really just found one study that referenced it at all and it's not very helpful.  Scroll down though, the CBT part is very encouraging.
Because this is such a specific topic really the only thing I found in relation to pharmaceuticals and jealousy was...if you have parkinson's and you are taking dopamine agonists, you can get "delusional jealousy".  So I'd avoid dopamine agonists...maybe?  But you probably don't have parkinson's.  It could be extrapolated to the general population to just say "hey, dopamine agonists may cause 'delusional jealousy'" but that's unlikely - and kind of useless information.  MAYBE you could try a dopamine antagonist (antipsychotic) but those things SUCK so much - just trust me it's not worth it...in fact it's a stupid idea to bring up.

Mov Disord. 2012 Nov;27(13):1679-82. doi: 10.1002/mds.25129. Epub 2012
Nov 13.
Dopamine agonists and delusional jealousy in Parkinson's disease: a
cross-sectional prevalence study.
Poletti M, Perugi G, Logi C, Romano A, Del Dotto P, Ceravolo R, Rossi
G, Pepe P,  Dell'Osso L, Bonuccelli U.
Department of Neuroscience, University of Pisa, Pisa, Italy.
BACKGROUND: Delusional jealousy (DJ) has been described in patients
with Parkinson's disease (PD) on dopaminergic therapy, but a role for
dopaminergic therapy in DJ has not been established. METHODS: The
current cross-sectional study on DJ investigated its association with
dopaminergic therapies compared with their associations with
hallucinations  and its prevalence in PD patients. Eight hundred five
consecutive patients with PD were enrolled between January 2009 and
June 2010. RESULTS: DJ was identified in 20 patients (2.48%) and
hallucinations in 193 patients (23.98%). In the multivariate logistic
regression analyses, dopamine agonists were significantly associated
with DJ (odds ratio, 18.1; 95% CI,
3.0-infinity; P = .0002) but not with hallucinations (odds ratio, 0.73; 95% CI,
0.49-1.10; P = .133). CONCLUSIONS: These findings suggest that dopamine agonist treatment represents a  risk factor for DJ in PD
independent of the presence of a dementing disorder, and the presence
of this additional nonmotor side effect should be investigated in this
clinical population.
Copyright © 2012 Movement Disorder Society.
PMID: 23150469  [PubMed - indexed for MEDLINE]

Edit
Now this was an interesting mini-study I came across along with a whole bunch of other results with the word "pathological jealousy."

J Clin Psychiatry. 1990 Aug;51(8):345-6. Successful fluoxetine
treatment of pathologic jealousy. Lane RD. Source Department of
Psychiatry, University of Health Sciences, Chicago Medical School,
Ill. Abstract A 39-year-old man suddenly became convinced that his
wife had once been unfaithful to him, and soon thereafter he became
depressed. Symptoms of depression responded to imipramine, but the
jealousy did not. A trial of fluoxetine was attempted because of the
obsessional nature of the jealousy. Fluoxetine 60 mg/day resulted in
complete remission of the pathologic jealousy, consistent with the
known efficacy of fluoxetine in obsessive compulsive disorder. PMID:
2380161 [PubMed - indexed for MEDLINE]

However, once again, I'm sure that's not the only affect he experienced.  THere were also a few hits with risperdone and primazone actually.  They didn't even have abstracts tho.
Then we have the implication that it may be involved in OCD:

Aust N Z J Psychiatry. 1997 Feb;31(1):133-8.
Morbid jealousy as a variant of obsessive-compulsive disorder.
Parker G, Barrett E.
School of Psychiatry, University of New South Wales, Randwick,
Australia.
OBJECTIVE: To present a representative case vignette and review
several previous  reports, and to then suggest that a percentage of
those with morbid jealousy may  have a variant of obsessive-compulsive
disorder (OCD). CLINICAL PICTURE: A patient presented volunteering a
diagnosis of depression and  anxiety following recent work and marital
stresses, before describing recent jealousy and harassment of his wife
over an earlier relationship. Obsessional thinking patterns and
compulsive behaviours are described, and it is proposed that the
picture supports a diagnosis of obsessive-compulsive disorder.
TREATMENT AND OUTCOME: The patient was treated as if he had an
obsessive-compulsive disorder, and reported dissipation of his
concerns after cognitive-behavioural intervention. CONCLUSIONS: The
proposition is an important one as a diagnosis of morbid jealousy
often invites therapeutic pessimism, and as managements effective for
OCD (both drug and behavioural) may well be helpful.
PMID: 9088498  [PubMed - indexed for MEDLINE]

Which ends with successful treatment with cognitive behavioral therapy as well as (they insinuate) some pharmaceutical treatment having to do with his OCD.
This leads me into my next section though:
Therapeutic
In my opinion:

Jealousy is so specific that said person with jealousy is going to
have to deal with it with something like CBT (although there are several medicines that >could help to treat it...you would probably agree with me that some of their side affects >arn't worth it if one were to try them, said jealous person also has to consider whether >or not their jealousy is "pathological") - not to sound like a
broken record.  There just isn't anything as proven out there.  Said
jealous person also needs to do things that expands their "options"
which would be the ultimate cure - even if it's just meeting randoms
on plenty of fish, there's not much to lose.  In my opinion, it should
be looked at as just gambling or like a slot machine.  Otherwise, if
said jealous person does not change any of their habits....the pattern
of jealousy will continue.

Now I'm going to give you some (the very rare) CBT studies involving specifically jealousy.  I don't have access to the full text of these, if you do - maybe you want to look into them more.  If you generalize "jealousy" into "depression" then I don't even need to really cite all of the studies that show how much CBT works.

Br J Psychiatry. 1996 May;168(5):588-93.
The effectiveness of cognitive therapy in the treatment of
non-psychotic morbid jealousy.
Dolan M, Bishay N.
Ashworth Hospital, Maghull, Liverpool.
BACKGROUND: Although a cognitive-behavioural formulation of morbid
jealousy has been described there is little empirical research into
the practical usefulness of this model. This study evaluated the
effectiveness of treating non-psychotic morbid jealousy using a
cognitive approach. METHOD: Cognitive-behavioural and emotional
measures of jealousy were calibrated  by comparison with 40
non-jealous normal controls. These instruments were used as measures
of change to assess the effectiveness of cognitive therapy in altering
cognitive errors in 30 morbidly jealous out-patient referrals, divided
into delayed and immediate treatment subgroups to assess the stability
of the condition. Both groups completed all measures immediately
before and after treatment, and at follow-up. RESULTS: The instruments
demonstrated significant differences between jealous and non-jealous
subjects on cognitive-behavioural and emotional aspects of jealousy.
The delayed treatment group showed no significant alteration in scores
on any of  the instruments after 12 weeks on the waiting list,
confirming the stability of the condition. In the majority of cases
cognitive therapy aimed at the modification of dysfunctional cognitive
processes resulted in a significant improvement on all jealousy
measures, immediately after treatment and at follow-up. The
improvement reported by patients was supported by the partner's
ratings. CONCLUSION: The results support the postulation of the
cognitive model that modification of cognitive schema by a
schema-focused treatment package results in a significant reduction in
disturbance in all aspects of the jealousy syndrome.
PMID: 8733797  [PubMed - indexed for MEDLINE]

Next:

Br J Psychiatry. 1989 Mar;154:386-9.
An uncontrolled study of cognitive therapy for morbid jealousy.
Bishay NR, Petersen N, Tarrier N.
North Manchester General Hospital, Crumpsall.
Thirteen patients presenting with morbid jealousy were treated using a
cognitive  approach adapted from Beck's cognitive therapy for
depression. Cognitions in morbid jealousy showed the characteristics
of automatic thoughts as described by  Beck, and were based on faulty
assumptions derived from interpretations of past experiences. The
cognitive treatment directed mainly at the faulty assumptions resulted
in improvements in TEN (10 out of 13!) patients and no change in one; two patients
dropped out of treatment. The results are considered encouraging.
PMID: 2597841  [PubMed - indexed for MEDLINE]

Once again if one were to just generalize the "jealousy" to depression, then click below.  There's a wide variety of them.
http://www.ncbi.nlm.nih.gov/pubmed/?term=cognitive+behavioral+therapy+depression


Sensory dissonance: Will the visual or auditory channel win? Is there any research showing that our visual channel takes precedence over the auditory channel (or vice versa) if there is some dissonance between them?
Examples:

Say a person driving a car approaches at fast speed a road split bang in the middle, the person next to her shouts "Right!!!" but raises his arm and clearly pointing to the left.

Being shown the word 'Red' (coloured red) but simultaneously hearing the word 'Blue', will subjects press the red or the blue button?

Yes. The phenomenon is usually referred to as Visual Dominance or Visual Capture.

A very nice demonstration of it, is known as McGurk Effect, in which our vision of the speaker's lips biases our perception of the sound we hear [1]. The McGurk Effect can be seen in a demo video here. Another demonstration of a similar effect is ventriloquism, in which we perceive the sound as coming from somewhere "probable" (like a puppet's vigorously moving lips) and not from its true origin.

One early scientific research into the matter of resolution of conflicting information between senses was done by James Gibson, in a study from early 1930s [2], in which subjects wore prism spectacles, that made straight lines appear curved. Although this was not the main topic of the research, he reports that

  When a visually curved edge such as a meter stick was felt, it was felt as curved. This was true as long as the hand was watched while running up and down the edge. If
  the eyes were closed or turned away, the edge of course felt straight, as it in reality was. This dominance of the visual over the kinsesthetic perception was so complete that when subjects were instructed to make a strong effort to dissociate the two, i.e. to 'feel it straight and see it curved,' it was reported either difficult or impossible to do so.

Posner et al. [3] cite several studies showing visual dominance over proprioceptive, haptic and auditory information, both in perception and in memory judgments, and try to explain the origins of this effect.

Specifically addressing your question of vision versus audition, Colavita [4] conducted a study in which

  Human Ss matched an auditory and a visual stimulus for subjective magnitude. Then each stimulus was used as a cue in a reaction time task. On occasions when both stimuli were presented simultaneously, Ss’ responding was seen to be dominated by the visual stimulus. Of further interest was the finding that on some occasions of simultaneous light-tone presentation Ss were unaware that the tone had been presented. This apparent prepotency of the visual over the auditory stimulus was seen to persist across a variety of experimental conditions, which included giving Ss verbal instructions to respond to the tone when both stimuli were presented simultaneously.

However, there are also reports of the opposite case, visual information is dominated by other sources, for example by haptic information when vision is blurred [5].

Recently it has been claimed that it integration between senses is done an optimal way, i.e the more accurate source in each situation is given more weight in their combination, or relied upon to a larger extent [6]. Since vision is usually very accurate in terms of location and shape of objects in the world, it tends to be dominant more often then other senses.

References

McGurk, H., & MacDonald, J. (1976). Hearing lips and seeing voices.
Gibson, J. J. (1933). Adaptation, after-effect and contrast in the perception of curved lines. Journal of experimental psychology, 16(1), 1. PDF
Posner, M. I., Nissen, M. J., & Klein, R. M. (1976). Visual dominance: an information-processing account of its origins and significance. Psychological review, 83(2), 157. PDF
Colavita, F. B. (1974). Human sensory dominance. Perception & Psychophysics, 16(2), 409-412.
Heller, M. A. (1983). Haptic dominance in form perception with blurred vision. Perception, 12(5), 607-613. PDF
Ernst, M. O., & Banks, M. S. (2002). Humans integrate visual and haptic information in a statistically optimal fashion. Nature, 415(6870), 429-433.


Are the human cerebral hemispheres only connected via the corpus callosum? Are the human cerebral hemispheres only connected via the corpus callosum? Or is there any other structure for interaction between the left and right hemispheres?

The corpus callosum is a massive horizontal white matter tract (commissure) that connects the two hemispheres and it is considered the most important route of communication between the hemispheres.

However, there are five additional commissures that cross the midline, namely:

Anterior commissure, connecting the two olfactory bulbs and the temporal cortices;
Hippocampal commissure (psalterium), connecting the two hippocampal formations;
Habenular commissure, connecting the habenular nuclei;
Posterior commissure, connecting the pretectal nuclei, mediating the consensual pupillary light reflex;
Supraoptic commissures (a. Gudden's commissure, or ventral supraoptic decussation connecting the medial geniculate bodies and b. Meynert's commissure, connecting the two suprachiasmatic nuclei*).

Below figure shows the corpus callosum and the anterios commissure:

Saggital section through the human brain showing the corpus callosum and anterior commissure. Source: Brain Atlas.

*The exact connection of Meynert's commissure I am unsure of. This is the best I could do.


Asking for illogical things to make extreme views normal? A couple of months back I was reading an article about how politicians were asking to make decisions that are way beyond possible (name it unreasonable, unacceptable, illogical) just as a medium of getting extreme views to become (to be seen as) normal and/or acceptable. What is the name of this effect?

It is a concept called "Overton Window". I finally found the article. It is not an effect though:

  There’s a concept in political theory developed by Joseph P. Overton which suggests that there’s a “window” of acceptable ideas and policy proposals in public discourse. Everything inside the window is normal and expected, while everything outside the window is radical, ridiculous, or unthinkable. And Overton argued that the easiest way to move that window was to force people to consider ideas at the extremes, as far away from the window as possible. Because forcing people to consider an unthinkable idea, even if they rejected it, would make all less extreme ideas seem acceptable by comparison -- it would move the “window” slowly in that direction.


How to interpret intelligence test scores for an individual who has taken a test multiple times in quick succession? Specific context: A test subject took the same Raven's Standard Progressive Matrices IQ test three times and first scored 115, then 107, and finally 143. The same test was taken three times within 3 and a half hours. Since all three scores are different and appear random, how can one  asses these results? i.e. Assuming the individual did not cheat, what can be said about the intelligence of  test subject?

More generally:

How should one interpret intelligence test scores for an individual who has taken the same form of the same test multiple times in quick succession?

General points about practice effects

Intelligence tests differ in how much they are subject to practice effects.

Practice effects can also be distinguished:

Time between taking the test: The shorter the timeframe the more likely you will see practice related improvement.
General practice on similar tests and similar items versus practice on the same set of items. In general, practice effects will be greater where the items are identical between test sessions. Adaptive testing where items change each time should show fewer practice effects.
Whether feedback is present. In general participants do not get feedback on what was or was not the right answer, but if they do receive such feedback, then practice effects will be much greater, especially for item specific transfer.

Test-retest variation

Another general point is that intelligence tests have a level of reliability such that a score on a test is only an estimate of an individual's true standing on the latent trait being measured. So obviously, some variation between administrations would be expected purely based on the standard error of measurement.

That said, the general model of test-retest reliability assumes reasonably controlled testing conditions and a participant that is applying reasonable effort.
When these conditions are not met, you could see much more variation:

If a test taker applies minimal effort or is distracted, they may get a much lower score than their true level.
If a test taker cheats in some way they may get a much higher score than their true level.

Issues of administration are more likely in an online environment particularly where there is either (a) no consequences for not applying full effort, or (b) an incentive to cheat.

Interpreting scores of someone who has taken a test multiple times

In general, if you are trying to measure intelligence, you should administer the test once and that first measure would be the measure of their intelligence.

Test administrations that follow immediately afterwards would be contaminated by practice effects. Unless you have a very good understanding of how practice effects operate and how they can be controlled for, then it would be difficult to incorporate information from these subsequent administrations.

That said, if you had additional information that said that on the first administration the participant was not concentrating or fundamentally failed to understand the test, then you may wish to tentatively rely on the score from a different administration.

In addition, a pattern of scores that differ by three standard deviations (e.g., 100, 115, 145) may suggest either that the test has reliability issues or that something strange is happening for that particular individual that you want to look into.