Can someone clarify whether the term "heuristic" as used in psychology can be used to refer to an intentionally chosen strategy? In my cognitive psychology class, we discussed heuristics. An example of a heuristic is loss aversion. Thus, in this context, a heuristic seems to be a general rule of thumb for how people behave.

But I was under the impression a heuristic was "any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals" (source: Wikipedia).

As an example, let us consider a coat rack. One might suppose that putting my coat on a coat rack is a type of problem solving strategy because it allows me to always find my coat at that location. Thus, the problem being solved would be "How can I always know where my coat is."

Can someone clarify whether the term "heuristic" as used in psychology can be used to refer to an intentionally chosen strategy (as opposed to loss aversion which is just "instinctive")?

Short Answer:

Yes it can.

Long Answer:

According to Wikipedia,

  A heuristic is “any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals.” Source: https://en.wikipedia.org/wiki/Heuristic.

This is a good general definition that seems to adequately capture the meaning behind "heuristic" as used in different fields. However, one must be careful to understand the specific use in a given context.

With regard to psychology, there seems to be some confusion because there are both intentional and unintentional heuristics.   Examples of unintentional ones are the availability heuristic. Some of the unintentional ones are more prominent and have received more attention and, as a result, I am not sure this distinction that there are "intentional" heuristics is always made.

However, according to Tversky and Kahneman (Nobel laureate in Economics),

  The term judgmental heuristic refers to a strategy ― whether deliberate or not ― that relies on a natural assessment to produce estimation or a prediction. One of the manifestations of a heuristic is the relative neglect of other considerations (Tversky and Kahneman, 294).

  Source: "Extensional Versus Intuitive Reasoning: The Conjunction Fallacy in Probability Judgment" by Tversky and Kahneman in Psychological Review Vol. 90 No. 4, 1983.

Note: the notion of a "judgmental heuristic" means simply a heuristic used in the mental faculty of "judgement," which I will not attempt to define.


What happens to someone missing teenage years of development? Hypothetically, let's say a person were to fall into a coma as an adolescent for several years, until they were a physical adult.

Would that person, assuming the brain was still fully functional upon awakening, still maintain the immaturity and impulsiveness of a teenager, and if so, could it be corrected by just trying to emulate adult life (effectively skipping teenage years of development), or are the experiences of a teenager still necessary to progress to an adult state of mind (aka, they would still need to have those experiences now in order to mature emotionally/mentally/etc.)?

Whilst typing this answer I upvoted this question as it points to very interesting theories of drive, motivation, and personal development.

Short Answer

If you take on board the theories surrounding life-span human development, there is an element of truth in your hypothesis.  Elements of immaturity and impulsiveness can still linger for various reasons and supposing there are no physical reasons for development delays, the reasons for the stagnation in cognitive development would need to be addressed through therapy in order for the person to be able to successfully move forward in life.

Long Answer

Although there is an element of opinion expressed in the underlying theories I am about to outline, the theories can easily be demonstrated in many different ways.

When looking at developmental issues, there are 5 spectrum models of development which theorists – and people in general – often disagree. (Miller, 2010; Sigelman & Rider, 2012):

Goodness vs Badness of Human Nature
Humans are innately good, bad or neither
Nature vs Nurture
Genes, biology, and maturation vs experiences, learning and social influences
Activity vs Passivity
Humans shape their environments vs environmental forces shape humans
Continuity vs Discontinuity
Changes are gradual vs dramatically through life
Universality vs Context Specificity
Development is similar between people and cultures vs considerable differences between people and cultures

First of all we need to look at how the theory has been developed.

The prime theories of development which play a part in answering this question lay in Psychodynamic theories initially developed by Sigmund Freud and developed further with adjustments to his theories by Erik Erikson.

Sigmund Freud's Drive Theory and Stages of Development

Drive Theory

Sigmund Freud argued on the debate of Nature vs Nurture and Good vs Bad, especially when he wrote his 2 essays Thoughts for the Times on War and Death around 6 months after the outbreak of World War 1.  I am not sure where Freud stood on the other spectrums, although I would say that he stood on the universality side of Universality vs Context Specificity, as I believe he saw everyone had the same motivational drives and therefore everyone would react to situations in the same way.

With Sigmund Freud, lot of people get hung up on the sexual elements of his theories when really, Freud’s theories centres on his motivation and drive theory and they centre on all sorts of pleasure.  We are motivated towards whatever brings pleasure and are motivated away from pain, difficulty, destruction, confusion, etc.

With drive theory centring on Eros and Thanatos along with the elements of the self (id, ego and super-ego), he is explaining resistance and why people use avoidance tactics through ego-defence mechanisms such as repression, denial etc. The Freud Museum’s website explains this too, along with topics such as the Oedipus Complex (Freud Museum London, n.d.).

I have seen Freud’s drive theory in play in many different ways.  People who I have been supporting after being assaulted often display these characteristics.  Although not always, they will avoid at all costs, anything they feel will put them in the same situation again, even if that means sacrificing personal and social interactions.

Some will also seek other forms of pleasure, either just for the pleasure they gain from it, or for the purposes of blocking out bad feelings, memories and emotions they are suffering from due to the past experiences haunting them through flashbacks etc.

Even those who have not experienced assault display drive theory traits when you look at the effects of commercialism in society.  Everyone looks for the things that will give them pleasure, whether it is the latest mobile phone, laptop or computer; or if it is a future holiday or bigger home.  The increase in readily available loans such as payday loans also make things more accessible and those who find difficulty paying them back avoid looking at the letters of demand, burying their head in the sand in the hope that they can deal with it later or it will just go away.

Stages of Development

The stages of development are a central element of Freud's Drive Theory.  Each of the stages:

Oral (Birth - 1 year approx.)
Anal (1 – 3 years approx.)
Phallic (3 – 6 years approx.)
Latency (6 – puberty approx.)
Genital (Puberty–death approx.)

is associated with a particular conflict that must be resolved before the individual can successfully advance to the next stage.

Erikson’s Life Stages

Erik Erikson’s 8 life stages of man, originally put together in 1950 in his book Childhood and Society, reframes Freud’s life stages and expands them.  Each stage is a dilemma and the resolution of each dilemma results in either a positive or a negative outcome. (Roche, 2009)

In Erikson’s life stages, Freud’s oral stage is the stage of trust vs mistrust, the anal stage is autonomy vs shame and doubt, the phallic stage is initiative vs guilt, the latent period is industry vs inferiority and the genital stage is identity vs role confusion.

Later, Erikson split the genital stage and labelled the puberty period of genital stage as identity vs role confusion and the later part of genital stage is intimacy vs isolation (Erikson & Erikson, 1998).

There were 2 other stages – Generativity vs Stagnation (or Fertility vs Sterility (Roche, 2009)) and Ego integrity vs despair – whilst a 9th stage was added in 1998 as the Eriksons came to believe that, “the role of old age needs to be reobserved, rethought” (Erikson & Erikson, 1998: p. 62).

In the ninth stage (around the 80s/90s), all first eight stages go in reverse quotient order. For example, intimacy vs isolation becomes isolation vs intimacy – years of intimacy and love often give way to isolation and deprivation.  Relationships become “overshadowed by new incapacities and dependencies”.

Looking at how issues have affected people I have spoken to, the first 8 life stages are to me more like stages of assimilation of fact which can advance and recede at different times in life.  Different facts will be at different stages of assimilation.

Take for example identity vs role confusion.  You can feel very secure in your identity within society but then something can happen which can shake that sense of identity to the point where you start to question it again.  Using this “life-stage” as an example, if you speak to a man who has been raped, for many different reasons he may have questions surrounding his sexual identity which he didn’t have before.

He could then misinterpret the situations he was in and re-evaluate and re-introject his sexual identity in the wrong way, which when revisiting the past in therapy can then cause more pain and anguish having to yet again re-evaluate his sexual identity.

When looking at this theory in the context of life stages and not stages of assimilation, the Eriksons’ revisiting of the life stages in 1998 highlights how you also need to look at these stages in the context of time-frame in which it was written.  They were originally put together in the late 40s and put into a book in 1950.  Expectations of children and adults were different then and so the timeframes of each stage may need to be adjusted and re-evaluated, however the stages still hold as being valid.

References

Erikson, E. H. & Erikson, J. M., 1998. The Life Cycle Completed. New York: W.W. Norton.

Miller, P. H., 2010. Theories of developmental psychology. New York: Worth.

Roche, D., 2009. Mapping the Human Phenome. [Online]
Available at: http://thewayitis.info/thewayitis/inhumandev/epigenetics/mapphenome/p71.html
[Accessed 16 March 2017].

Sigelman, C. K. & Rider, E. A., 2012. Life-Span Human Development. 7th ed. Belmont, CA: Wadsworth.

Freud Museum London, n.d. Are Freud's Theories All About Sex?. [Online]
Available at: https://www.freud.org.uk/education/topic/10567/subtopic/10571/
[Accessed 16 March 2017]


How to become a philosophical zombie? I was wondering if the following mental state was possible and if so, if it was documented.

The concept would be not to be conscious for a while, to be in some way in automatic mode. And because of any stimulus, return to a normal state with all the recent memories in mind but the impression that they all happened in a second.

The goal is clearly not to have to wait for a given event or to put an unpleasant period of time behind you.

A true philosophical zombie would form the same memories of being conscious that a conscious human would. By definition, a p-zombie is atom-for-atom identical to a real person, and would be impossible to distinguish by any means, even through the memories stored in the zombie's brain! If consciousness was one day imbued into a 30-year-old philosophical zombie, they would not realize that they had previously not been conscious.

As a corollary, science could never know if it had successfully produced a p-zombie, because if you gave someone the zombie pill, nothing measurable would change and after it wore off they would not know anything happened. It would be indistinguishable from a placebo.


Is there a limit on the rate at which incoming information can be comprehended? I recently started a course on "Speed Reading", which aim is to read faster whilst holding the level of comprehension constant (so not to its detriment, but not aimed at improving comprehension either).

Now, for the case of reading, I imagine we can define a rate at which information is been given to the brain. So, the faster you read (holding comprehension constant), the higher such rate is. Clearly, the aim of such training programs like "speed reading" is to move that rate up.

Is there an upper limit to such rate, perhaps because of biological reasons? Does it depends on the person? Can we say, for example, that it is biologically impossible to comprehend a text reading faster than 1,000 words per minute? Is there any evidence of such limit? This information would be useful to understand the scope of improvement possible on this issue.

I have tried speed reading myself in the past. From the research papers I have read back then, it seemed like there is no basis or evidence to the claim that with practice, reading speed can increase to more than 600-700 words per minute without any loss of comprehension (Some of the most bizarre claims include 25,000 words per minute. I would have been more impressed if the person claiming it wasn't selling online courses about speed reading for large sums of money).

I can't find the studies I found back then, but a meta-analysis by Keith Rayner†, Elizabeth R. Schotter, Michael E. J. Masson, Mary C. Potter, Rebecca Treiman (2016) seems to show that reading pace is highly determined by language skills and an extensive vocabulary. They show that generally there is a trade off between pace and comprehension, and some of the claims for a very high reading pace were based on prior knowledge of the texts. However, mild improvements can be achieved with practice. This article looks extremely fascinating and I wish I had the time to read all of it.

Edit: Only now do I realize how ironic my last remark was.


Is it possible to sleep with your eyes open? It is generally observed that animals and human alike close their eyes when they sleep. It looks seemingly natural.

But I have heard (and might have observed one too, just not sure whether he was actually sleeping or not) that there are certain people who can fall asleep with there eyes open.

So, is it possible to sleep with your eyes open?

Nocturnal lagophthalmos is the search term you're looking for.  But it's less that they "can" fall asleep with their eyes open and more that they "can't" close their eyes during sleep:

  Nocturnal lagophthalmos is the inability to close the eyelids during
  sleep. Lagophthalmos is associated with exposure keratopathy, poor
  sleep, and persistent exposure-related symptoms. There are a variety
  of causes of lagophthalmos, grouped as proptosis/eye exposure
  etiologies and palpebral insufficiency etiologies.


Causality regarding neurotransmitter imbalance and depression Neurotransmitter imbalances are blamed for various psychiatric conditions (depression, ADHD, etc).  Clearly plasma levels of neurotransmitters are confirmed to be abnormal in some people with such conditions.  BUT, has causality ever been proven?
That is; for example, does a serotonin deficiency cause depression or does depression cause a serotonin deficiency?

It is clearly possible to be "situationally depressed" caused, for example, by grief or the loss of a loved one.  Do such people also experience a neurotransmitter imbalance?

Is there a definitive study of this?

I have what is mostly a frame-challenge to your question as an answer: the simple "neurotransmitter imbalance" hypothesis is a bit outdated, and it hasn't been strongly influential in a research context for a very long time.

Rather, it is an extremely oversimplified way to try to explain that there are brain differences involved in depression: that it's a real and physical disorder rather than something "made up" or "all in the head". This message might be useful for patients in explaining that their symptoms are not imaginary or something to just "get over", and also for pharmaceutical marketing of those medications. It may also cause harm (see Kemp et al 2014).

The hypothesis is originally based on studies that showed both a) that drugs impairing serotonin signalling could create depressive symptoms in animal models, and b) that drugs like selective serotonin reuptake inhibitors (SSRIs), which (at least initially) increase synaptic availability of serotonin, could treat depressive symptoms. Since then, more work shows that it is very questionable to consider reduced levels of monoamines like serotonin purely causative for depression, because depletion of such monoamines fails to produce depressive symptoms in healthy subjects (France et al 2007 review several such studies).

However, other neurotransmitters are also involved, and serotonin itself acts through numerous receptor subtypes (even completely different families), and many of these influence levels of other neurotransmitters as well. Levels of glutamate, dopamine, and norepinephrine are also both implicated in depression, but like with serotonin there is no clear, simple story.

In the brain, it's not just how much of a substance is present, but where it is released, when it is released, and in what pattern it is released. The same neurotransmitter in different brain areas can have different or even opposite effects. A neurotransmitter released 100 times in 1 second or 100 times in 100 seconds can have different or even opposite effects.

There is also a strong likelihood that depression and related conditions including anxiety disorders are not specific conditions but rather umbrella descriptions for a host of different brain dysfunctions. If there was a simple story, it wouldn't be nearly as complicated to treat.

France, C. M., Lysaker, P. H., & Robinson, R. P. (2007). The" chemical imbalance" explanation for depression: Origins, lay endorsement, and clinical implications. Professional Psychology: Research and Practice, 38(4), 411.

Kemp, J. J., Lickel, J. J., & Deacon, B. J. (2014). Effects of a chemical imbalance causal explanation on individuals' perceptions of their depressive symptoms. Behaviour research and therapy, 56, 47-52.

Lacasse, J. R., & Leo, J. (2005). Serotonin and depression: a disconnect between the advertisements and the scientific literature. PLoS medicine, 2(12).

Leo, J., & Lacasse, J. R. (2008). The media and the chemical imbalance theory of depression. Society, 45(1), 35-45.


How does the alpha brain wave frequency range distribute over the population? Alpha brain waves show up in your EEG when you close your eyes. Alpha waves are brain waves between 8 and 13 Hz.

How does this frequency range distribute over a population of people?

Alpha oscillations vary in frequency within a single subject from brain area to brain area (Başar, 2012),  likely because there is not a single phenomenon underlying all examples of alpha oscillations.  At this point in time, an answer to this question would be very difficult because we don't even know what alpha oscillations are.

Reference

Başar, E. (2012). A review of alpha activity in integrative brain function: fundamental physiology, sensory coding, cognition and pathology. International Journal of Psychophysiology, 86(1), 1-24.


Why prefer "99% fat free" to "1% fat"? In my experience I tend to find low-fat products labelled as "99% fat free" much more often than the equivalent "1% fat".*

Why is this so? To me it seems counter-intuitive, because it reminds me of psychological pricing, where retailers price things slightly less than round numbers, partly so that consumers under-perceive the price. If that same effect is happening with the "99% fat free" labeling, consumers would over-perceive the amount of fat.

Is it because the psychological pricing phenomenon doesn't apply in this case for whatever reason? Perhaps other phenomena are at play? Or perhaps it's something that doesn't have to do with the numbers?

*: I can't find a source for this unfortunately, and I'm aware that in some circumstances the "1% fat" form is the norm, for example with low-fat milk.

If that same effect is happening with the "99% fat free" labeling, consumers would over-perceive the amount of fat

I think you are misunderstanding the desired effect here. I don't see how "99% fat free" would lead to the impression that a product contains a lot of fat. My read is, "This is 99% fat free! That's really good!" as opposed to "1% fat" which more emphasizes the fact that fat is still present than the fact that it's not. Said another way, because 99 is a far higher number than 1, the brain is more positive about getting something that is really good (much higher fat-free percentage) than something that is slightly bad (very small fat percentage)

The other thing you may be overlooking is that "fat free" is a marketing term in and of itself. Products claim to be "fat free" in order to attract dieters / those looking to eat healthy. When comparing products people may choose the ones which have actively tried to reduce the amount of fat; this is what the "fat free" term is intended to convey. Compare that with milk, where "1% fat" really means "1% milkfat", a technical description of how rich the milk is (where "whole milk" is 3.25% - 4% milkfat typically), so the terminology is not used as a means to advertise that product as being better than the competition but rather as a means to identify the content of the product itself.


Correlation used as explanatory device in ''The neuroscience of Intelligence' I am currently reading Dr. Richard Haier's book The Neuroscience of Intelligence. I have a base knowledge of statistics, but I am confused about the following extract from page 80 (chapter 2.4):

  When correlations are computed in identical twins reared apart, the
  correlation is  also one way to estimate heritability, so a
  correlation of .70 indicates that 70% of the  variance in intelligence
  is due to genetic factors and 30% is not.

Is using correlation a valid way to estimate the heritability of a specific trait? I was under the impression that for a comparison of shared variance r² would have to be used, which would mean IQ is not 70% inherited, but only 49% (a huge difference!).

The author is simply not being explicit. The

  correlation

is neither r or r2, it is simply the relation between x and y.

Pearson's correlation coefficient, or r is a measure of the linear correlation between two variables. It's value is between +1 and −1, 1 being a total positive linear correlation, 0 means no linear correlation, and −1 is total negative linear correlation.

The coefficient of determination, or r2 has a value between 0 and 1. A value near 1 indeed indicates that most of the variation of the response data is explained by the different input values, whereas a value of r2 near 0 indicates that little of the variation is explained by the different input values.

Now to your book; 70% seems indeed like a lot. I thought it was approximately 40% and this is backed up by NIH and Scientific American that mention approximately 50%. However wikipedia mentions numbers up to 86% and back this statement up with influential articles. (Plomin & Deary, 2015) indeed postulate that

  The heritability of intelligence increases from about 20% in infancy to perhaps 80% in later adulthood.

Reference
- Plomin & Deary, Molecular Psychiatry (2015); 20: 98–108


Why do humans prefer symmetrical arrangement of objects? Most of the times, we associate symmetry with beauty. The symmetry may be in architectural/interior design for instance. Why would this be so ?

Indicator of genetic fitness argument

There is an evolutionary psychology argument. As with most evolutionary psychology arguments, the strength of the evidence is typically a bit fuzzy.

Symmetry in many aspects of the human body is functional. Such symmetry might be seen as the natural state that arises from a healthy life and a youthful body. In contrast various genetic abnormalities, diseases, and the like  can give rise to asymmetry (e.g., scars, moles, freckles, ageing processes, deformities, etc.).

The argument might continue that it is adaptive for us to seek out sexual partners  who appear genetically and environmentally fit where symmetry may be one indication of this fitness. One could even extend the evolutionary argument to suggest that it would be adaptive to avoid certain types of diseased individuals in order to reduce the risk of catching some disease, where various forms of asymmetry may be indicative of this.

How does this explain our desire for symmetry in physical objects? The perception of beauty in the environment might be seen as an extension of perceptions of beauty in other people.

Little and Jones also summarise this perspective

  One explanation for the preference for symmetrical faces comes from a
  postulated link to an evolutionary adaptation to identify high-quality
  mates (see Thornhill & Gangestad (1999) for review). Symmetry in human
  faces has been linked to potential heritable fitness (‘goodgenes’)
  because symmetry is a useful measure of the ability of an organism to
  cope with developmental stress (both genetic and environmental). As
  the optimal developmental outcome of most characters is symmetry,
  deviation from perfect symmetry can be considered a reflection of
  challenges to development. Only high-quality individuals can maintain
  symmetrical development under environmental and genetic stress and
  therefore symmetry can serve as an indicator of phenotypic quality as
  well as genotypic quality (e.g. the ability to resist disease: see
  Møller (1997) and Møller & Thornhill (1998) for reviews). This logic
  would lead to a preference for high symmetry mates as evolution will
  have favoured individuals who had preferences for high-quality mates
  over low-quality mates. Indeed, morphological symmetry appears to be
  related to reproductive success in many species, including humans
  (Gangestad & Thornhill 1997a; Møller & Thornhill 1998). For example,
  more symmetrical human males have more sexual partners than less
  symmetrical men (Thornhill & Gangestad 1994) and symmetrical males are
  also more likely to be chosen as extra-pair partners (Gangestad &
  Thornhill 1997b). Thus the link between symmetry and attractiveness
  may reflect that preferences for symmetrical individuals may be
  potentially adaptive.

Perceptual argument

Enquist and Arak (1994) articulate a perceptual clarity argument. They wrote (my bolding):

  Humans and certain other species find symmetrical patterns more
  attractive than asymmetrical ones. These preferences may appear in
  response to biological signals1–3, or in situations where there is no
  obvious signalling context, such as exploratory behaviour4,5 and human
  aesthetic response to pattern6–8. It has been proposed9,10 that
  preferences for symmetry have evolved in animals because the degree of
  symmetry in signals indicates the signaller's quality. By contrast, we
  show here that symmetry preferences may arise as a by-product of the
  need to recognize objects irrespective of their position and
  orientation in the visual field. The existence of sensory biases for
  symmetry may have been exploited independently by natural selection
  acting on biological signals and by human artistic innovation. This
  may account for the observed convergence on symmetrical forms in
  nature and decorative art.

References

Enquist, M., Arak, A. & others (1994). Symmetry, beauty and evolution. Nature, 372, 169-172.
Little, A.C. & Jones, B.C. (2003). Evidence against perceptual bias views for symmetry preferences in human faces. Proceedings of the Royal Society of London. Series B: Biological Sciences, 270, 1759-1763. PDF


What is the name for this form of "influence"? I have found that people are often "roused to action," activism and even zealotry by attributing either extreme of "nobleness" or "despicability" to their self or group identity.
I don't know if there is a name for this phenomena.  I'll give two examples to help pin this down.
Attribution of Despicability
For example, Fred is an evangelical who has an axe to grind with Catholicism.  Fred encounters an apathetic Catholic named Phil, who neither knows or cares anything about his alleged Catholic faith, and yet Fred proceeds to blast Phil verbally (under the appellation "you Catholics") for how despicable and anti-biblical their beliefs are.
Phil becomes very unsettled and defensive from this encounter, and subsequently chooses not just to learn his faith - but to defend it as well. Ironically Phil grows into a zealot for his Catholic faith due to Fred's negative outburst.  It could be said that Phil has (subconsciously?) resolved to prove Fred wrong or perhaps to attain a form of revenge?
Attribution of Nobleness
Jake, a young man, is an athletic but wayward soul.  He encounters a decorated army veteran named Gabe who says "I've been watching you for several days now lad, and I can tell you that in you is a greatness that is meant to be released."  The subsequent conversation inspires Jake to join the military and, indeed, Jake subsequently has a stellar military career that proves Gabe was right!
Wrapping Up
I realize that not every dynamic has a specific name in psychology, but it troubles me that the overall phenomena I'm outlining isn't represented in public dialogue, particularly when it comes to politics.  I believe the nation is becoming increasingly polarized and hostile because "attribution of despicability" is counter-productively generating the wrong kind of zealotry and thus ever-deepening unproductive contrasts.

"You leftists just want to destroy democracy".  Well, the "leftist" did not have an opinion about democracy before the accusation, but due to the judgmental accusation...the leftist began to study and embrace arguments of why democracy is evil.
"You rightists just want to subjugate minorities".  Well the "rightest" who had no particular sentiment before now adopts a passive-aggressive attitude about those who claim to support minorities and perhaps against minorities as well.

In short, both positive and negative accusation(s) have a catalytic or causal power.  Seen this way, in the case of negative accusations which we use to judge and condemn, the reality is that "we have met the enemy, and it is ourselves."
I wouldn't be surprised if psychology has two names which treat both the "attribution of nobleness" and the "attribution of despicability" as two different things, even though I see them as flip-sides of the same coin.
Any ideas?
Update
Until I learn more about this, and understand it better, I'm going to call the overall phenomenon "Manifest Testimony"...intentionally echoing the phonetics of the otherwise unrelated "Manifest Destiny."

I have some ideas about your first example. During my course of social psychology a learned about self/social categorization, two concepts that shape how individuals perceive groups. Here are some quick definitions.

Self categorization:

  the process of seeing oneself as a member of a social group (Smith, Mackie & Claypool, 2014)

Social categorization:

  The perceptual classification of people, including the self, into categories (Forsyth, 2014).

According to self and social categorization people automatically view themselves as part of a group and others as part of a group also. I think Phil in your example still views himself as part of the group "catholics" (even though he does not know much about it) and Fred as part of the group "Evangelics". After that there are quite a view phenomenons that suggest people care about their beliefs and about their group status. One good example in this context is the ingroup-outgroup bias:

  The tendency to view the in-group, its members, and its products more positively than other groups, their members, and their products. Ingroup favoritism is more common than outgroup rejection (Forsyth, 2014).
  So, Phil might realize that he is part of the group "catholics" and subsequently becomes more defensive.

Also it could be possible that Phil experiences some form of cognitive dissonance (an adverse psychological state that occurs when an individual simultaneously holds two conflicting cognitions (Forsyth, 2014)), because he claims he is part of the catholic group but is blatantly confronted that he barely knows anything about his group. This might lead to the attitude change you suggest, that he wants to learn more about catholicism.

Of course this is more a description of how processes in groups can work and how people influence each other based on these processes. It is in no way a description of a scientifically backed up process/theory, although the terms used in my description are of course backed by science.

As for the second example, I personally believe there could be a lot of factors that lead to Jake's decision of joining the army. I think it would be hard to pin it down on the few words of the army veteran.

However, I am not an expert on social psychology. So I hope this information helps understanding social processes but it might not be a complete and conclusive answer. If you are interested in social psychology and group dynamics then I recommend to check out Forsyth's book Group dynamics. It explains concepts wihtin the field very well and uses informative examples. Hope this helps in some way.

References

Forsyth, D.R. (2014). Group dynamics (6th ed.). Belmont, CA: Cengage Learning. ISBN- 13 9781133956532

Smith, E.R., Mackie, D.M., & Claypool, H.M. (2014). Social Psychology (4th ed.). New York, NY: Psychology Press. ISBN 978-1-84872-894-3


Is unconsciousness actually superior to the conscious mind? In Blindsight by peter watts, the author mentions something called a "neurological bureaucracy", in which the conscious mind has little purpose other than acknowledging what has already been thought and done by the unconscious mind and taking credit as its own work. The book uses examples like Eureka moments and a musician performing, where the unconscious mind takes control over the conscious mind and is superior.
"Every dancer and acrobat knows enough to let the mind go, let the body run itself."
Despite being fairly convincing, the theory seems to be in conflict with the very nature of human cognitive process. Does such claims has any backing in current scientific discovery?
Is being totally unconscious superior? Or is it only superior to a conscious mind in a "Complete" Chinese room scenario, where the system/brain has already been fed with enough information to compute all its "results"?

Q: Is unconsciousness actually superior to the conscious mind?
Short answer:
In some aspects, yes; in some, no. Both unconsciousness and consciousness are essential for organisms that have evolved to have consciousness; these organisms can’t survive without both of them.
Long answer:
All mental processes are unconscious in the sense that we never are conscious of the processing at any of the processing steps in any mental process (e.g., we never are conscious of the processing at any of the processing steps in the processing processes of vision, sound, taste, language, decision making, etc. and never know what the processing at each step is like); we are conscious of only the results of some mental processes (e.g. we are conscious of the vision, sound, taste, meaning of words, and decisions resulting from the corresponding mental processes and know what they are like) while the vast majority of mental processes have unconscious results, such as the information of the pressure in the blood vessels, blood pH level, and blood electrolyte and hormone levels (e.g., we never are conscious of the pressure in the blood vessels, blood pH level, and blood electrolyte and hormone levels and never know what they are like).
(N.B. To avoid confusion, it should be note that mental processes whose results we can be conscious of are often called conscious mental processes even if we are not conscious of the processing at any step of their processing processes, and that mental processes whose results we cannot be conscious of are often called unconscious mental processes.)
The major differences between unconsciousness and consciousness is that the following occur if something is conscious but do not occur if it is unconscious:

The mind has the awareness and experiences of what that something is like – what the vision of the house is like, what the sound of the song is like, what the taste of the honey is like, etc. (Compare these to the unconsciousness cases: the mind doesn’t have the awareness and experiences of what the blood pressure at 120 or 130 mmHg is like, what the blood pH of 7.35 or 7.45 is like, what the blood sodium level of 135 mEq/L or 140 mEq/L is like, etc.)

The mind can share the information of that something to its various parts that include the cognition part, the symbolizing part, and the storage part. Thus, it can think about, analyze, compare, and do other mental activities regarding that something intentionally; it can directly represent that something with symbols – written signs, sounds, gestures, etc. – thus, it can communicate information about that something to other members of its species; and it can intentionally memorize and recall that something, at least with some details and for some time. For example, we can do these activities (think about, analyze, compare, talk and write about, and memorize and later recall) to the vision of the house, the sound of the song, and the taste of the honey, but we cannot do these activities to the unconscious registration of the blood pressure, blood pH, and blood sodium level.

These properties of being globally available for various mental processes, being able to be stored and retrieved, and reportability certainly give organisms that have consciousness flexible response mechanism to cope with infinite challenges it may encounter in the environment and thus increase the survival chance of the organisms and their species.
Thus, although unconsciousness performs the vast majority of mental processes and are essential to life, there are something that is survival-promoting that unconsciousness cannot do while consciousness can. In the former case, unconsciousness may be considered superior while in the latter case consciousness is certainly superior.
Q: Is being totally unconscious superior?
A: From the discussion above, the answer is obviously “no”.
Q: Or is it only superior to a conscious mind in a "Complete" Chinese room scenario, where the system/brain has already been fed with enough information to compute all its "results"?
A: In real life, there are infinite, unpredictable challenges in the environment to tackle with. It’s impossible to feed the Chinese room with infinite amount of information for infinite scenarios in advance so that anyone in the room can automatically respond to each scenario correctly. This is true in the case of organisms as well. It’s impossible to have an unconscious system in any organism pre-fed with infinite information to cope with infinite challenges. That’s why consciousness evolves to tackle this problem of infinite challenges.
If it were possible to feed an infinite amount of information into a system, including an unconscious system, the answer to this question would probably be yes; but in real life, it’s not possible to do so.
References.

Earl B. The biological function of consciousness. Front Psychol. 2014;5:697. doi: 10.3389/fpsyg.2014.00697.

Dehanene S. Fathoming unconscious depths. In: Consciousness and the brain. Penguin Books. 2014. New York, New York, USA. ISBN 978-0-670-02543-5, 978-0-14-312626-3. p 47-88.

Dehaene S, Changeux JP, Naccache L, Sackur J, Sergent C. Conscious, preconscious, and subliminal processing: A testable taxonomy. Trends Cogn Sci. 2006 May;10(5):204-211. DOI: 10.1016/j.tics.2006.03.007.


Is the average IQ still 100? IQ tests have been around since Binet invented them in the early 20th century roughly 100 years ago. The point of the test was to measure your mental against your chronological age (hence the quotient) and then multiplied by 100, so that the average person's IQ was supposedly 100.

I have seen several claims (including this one) that IQs have risen steadily at about 3 points per decade since the early 1900s. So roughly 10 decades at 3 points each makes for what today ought to be a 130 point IQ.

Most tests today though, still score you on percentiles based on an average score of 100 points. How can these facts be consistent?

Intelligence Quotient is a relative score, comparing you to the current average. It is not a fixed, raw intelligence score.

  When current IQ tests are developed, the median raw score of the
  norming sample is defined as IQ 100 and scores each standard deviation
  (SD) up or down are defined as 15 IQ points greater or less,[2]
  although this was not always so historically. By this definition,
  approximately two-thirds of the population scores between IQ 85 and IQ
  115, and about 5 percent of the population scores above 125.[3][4]

....

  Raw scores on IQ tests for many populations have been rising at an average rate that scales to three IQ points per decade since the early 20th
  century, a phenomenon called the Flynn effect.

...

  Since the early 20th century, raw scores on IQ tests have
  increased in most parts of the world.[45][46][47] When a new version
  of an IQ test is normed, the standard scoring is set so performance at
  the population median results in a score of IQ 100. The phenomenon of
  rising raw score performance means if test-takers are scored by a
  constant standard scoring rule, IQ test scores have been rising at an
  average rate of around three IQ points per decade. This phenomenon was
  named the Flynn effect in the book The Bell Curve after James R.
  Flynn, the author who did the most to bring this phenomenon to the
  attention of psychologists.[48][49]

http://en.wikipedia.org/wiki/Intelligence_quotient

In addition to various IQ tests giving varying scores, each of them is also standardized to the current average intelligence score. So every test can give you a different score.
Put in other words: An old IQ-test will compare you to what was average IQ at the time the test was standardized - which may be lower than todays average.


What keeps the cerebrospinal fluid circulating? Is it pumped by something? What keeps the cerebrospinal fluid circulating? Is it pumped by something?

This picture from wikipedia seems to indicate that it pulsates as though it is pumped:

There is no evidence that the CSF has a pump. A link to a Chiropract Medicine page (a good one, from my reading) tells us that:

It is something of a misnomer to speak of CSF “circulation,” particularly in the spinal canal, as there is no continuous loop circulation of CSF as in the cardiovascular system. [CEREBROSPINAL FLUID STASIS AND ITS CLINICAL SIGNIFICANCE
Whedon et. al., Altern Ther Health Med. 2009 May–Jun; 15(3): 54–60.]

This is in keeping with the findings of decades of research in western medicine (M.D., Ph.D., D.O., etc.)

For quite some time, it has been known that CSF movement results from the formation of new CSF and motion of cilia on the surface of the choroid plexus and ependyma lining the ventricles. - Fluids and Barriers of the CNS

The "circulation" of the CSF, as already mentioned, is something of a misnomer. CSF is not known to "circulate" in the manner of blood. It does get agitated by pressure differentials, and it is 'circulated' in terms of being reabsorbed and replaced every 6-7 hours. Other than that, no circulation occurs.
Blood circulation is not generated only by the heart. Pressure differentials throughout the body affect the circulation of blood as well. One that is easily demonstrated (first documented in 1733) is the effect of intrathoracic (chest) pressure on circulation. The blood pressure of healthy people falls during spontaneous inspiration. When someone takes a deep breath, the blood return to the heart via the vena cava decreases, and pressure is exerted on the right atrium. Both cause decreased filling, which will drop blood pressure. Although this is best demonstrated with a blood pressure cuff, it can be demonstrated without. An unrecommended method is exemplified in a childhood game of passing out. A Valsalva maneuver (deep breath and glottal closure) decreases blood flow to the heart. Squeezing the chest further decreases return, resulting in fainting.
The same pressure differentials agitate the CSF. Additionally, smaller movements were seen with pressure differentials caused by the beating of the heart.

By employing this respiration-induced spin labeling bSSFP cine method, we were able to visualize CSF movement induced by respiratory excursions. CSF moved cephalad (16.4 ± 7.7 mm) during deep inhalation and caudad (11.6 ± 3.0 mm) during deep exhalation in the prepontine cisternal area. Small but rapid cephalad (3.0 ± 0.4 mm) and caudad (3.0 ± 0.5 mm) movement was observed in the same region during breath holding and is thought to reflect cardiac pulsations.

The image in the OP's question is of a patient with normal pressure hydrocephalus (NPH) showing pulsations of CSF with heartbeat, nothing more.
There are other factors that cause movement of CSF, but they are intermittent and variable.
Influence of respiration on cerebrospinal fluid movement using magnetic resonance spin labeling, Yamada et. al., Fluids and Barriers of the CNS 2013, 10:36
MRI showing pulsation of CSF


How many times on average do people wake up per night? It would be best if the answer could be broken down by age and sex, and even by other variables (alcohol-drinker vs teetotaller, etc).

If there's a difference between self-report data and data from studies that observe people sleeping, I'm interested in that too.

This image,

which I took from here, implies that waking up several times is normal, but the article doesn't provide any information on averages.

It may be that the median is more useful than the mean in this context.

Based on this paragraph from the Wikipedia article on hypnograms

On a hypnogram, a sleep cycle is usually around 90 minutes and there are four to six cycles of REM/NREM stages that occur during a major period of sleep.
Most SWS occurs in the first one or two cycles; this is the deepest period of sleep. The second half of the sleeping period contains most REM sleep and little or no SWS and may contain brief periods of wakefulness which can be recorded but are not usually perceived.
The stage that occurs before waking is normally REM sleep.

And this image (also from wiki):
Sample hypnogram showing one sleep cycle (the first of the night) from NREM through REM
A normal and healthy person usually wakes for a brief time after his/her REM stage was finished in each sleep cycle. So, if we consider A 7–8-hour sleep probably includes four cycles, and each cycle include at least one REM, then each person at least wake four times.


What are extrinsic motives? In a chapter on motivation in the book "Pädagogische Psychologie", I read that Schaffner and Schiefele say:

  Allerdings werden Zielorientierungen als kognitiv repräsentierte und
  bewusste Merkmale verstanden, sodass sie dem extrinsischen
  Leistungsmotiv näher stehen als dem intrinsischen.

  (English translation based on Google Translate)
  However, goal orientations are understood as cognitively represented and conscious features, so that they are closer to the extrinsic performance motive than to the intrinsic one.

Since the term 'extrinsic motive' was mentioned in just one sentence, I do not fully understand what it means.

I do know that we might make the distinction between implicit and explicit motives and that the awareness of the motive is a crucial factor in this scenario. But is there a justification to call cognitively represented features of which we are aware extrinsic motives?

I think the key distinction between intrinsic and extrinsic motivation is not the awareness of the motive, but the locus of origin of the motive.

We are very much aware of intrinsic motives. For example: Hunger- Going without food for a long time makes us hungry, a state we are aware of, and we consume food. The act of consuming food when hungry is intrinsically motivated, and emerges from within us, without the effect of any external agent. However, Ryan and Deci's self-determination theory (SDT) did not mention (as far as I know) intrinsic motives as being connected to a physiological need. SDT's intrinsic motives were connected to psychological needs, in doing activities which were enjoyable in themselves, unconnected to an external reward.

As you have mentioned, we are also aware of our extrinsic motives, for example, motivation to work a 9-to-5 job to earn money to buy food which satiates hunger, a primary need.

My interpretation is that since extrinsically motivated activities are oriented towards an external goal and since "goals are cognitive
representations of what individuals are trying to accomplish and their purposes
or reasons for doing the task" (3), hence the authors are stating that extrinsic motives have cognitive representations.

My conflict is that granted, extrinsic motivation is goal-oriented but isn't intrinsic motivation also goal-oriented? For example, mastery in a task if often considered to be intrinsically motivated. Does that not mean the mastery=goal? As you will see from the table of motivational terms in (4) (see Garcia and Pintrich, 1996 in the table), intrinsic motives are also goals, according to many behavioural scientists. That would make intrinsic motives to also be cognitively represented.

Quoting (3),

  In their discussion of the accessibility of motivational constructs, Murphy and Alexander really raise two issues; one concerns the consciousness or cognitive accessibility of motivational constructs and the other concerns the accuracy of individuals’ reports of their motivation. From an achievement goal theory perspective, the issue of cognitive consciousness or accessibility is not as major a problem as it may be for models that assume there are some ‘‘deeply-held, pervasive motives, needs, or drives’’ to use Murphy and Alexander terms (this issue). Goal theory assumes that goals are cognitive representations of what individuals are trying to accomplish and their purposes or reasons for doing the task. As such, they are inherently cognitive and assumed to be accessible by the individual; they are not unconscious motives as in psychodynamic theory, nor are they deeply held needs or motives as in some models of motivation (cf. Deci & Ryan, 1985; McClelland, Atkinson, Clark, & Lowell, 1953; Murray, 1938). In fact, the metaphor of ‘‘excavating’’ deeply held motives or needs and bringing them to the ‘‘surface’’ or into the ‘‘light’’ of day through various methods such as projective tests or intensive psychotherapy is not really applicable to achievement goal theory. In contrast, the discussion of goal constructs ﬂows from the general cognitive revolution in psychology and goals are assumed to be internal, cognitive representations or knowledge structures.

In conclusion, I don't understand why only extrinsic motives have been given a cognitive representation and not intrinsic motives, in the text.

I highly recommend you to go through (3) and (4), since this seems to be a matter of confusion regarding how motivational constructs are defined. There has been considerable debate regarding the definitions of motivational constructs and what concepts they encompass. The quoted line in the question seems to be a result of this very dilemma.

References:

1) Psychology, Ciccarelli, fourth edition.

2) http://ccdf.ca/ccdf/NewCoach/english/ccoachb/issue_b1c_basics.htm

3) Pintrich, P. R. (2000). An achievement goal theory perspective on issues in motivation terminology, theory, and research. Contemporary educational psychology, 25(1), 92-104.

4) Murphy, P. K., & Alexander, P. A. (2000). A motivated exploration of motivation terminology. Contemporary educational psychology, 25(1), 3-53.


Do people have an innate preference to take matters into their own hands? People usually want to make their own decisions. Those looking for spouses often listen to their inner romantic instincts and reject advice from more experienced people. Drivers are skeptical about self-driving cars and would feel safer driving themselves. In some cases, even when unjustified, people would rather take matters into their own hands.
A convenient explanation of this is overconfidence. People may be overly confident about their ability to choose the best decision. However, it seems that this is not everything.
Even those who know that it is better to let experts decide for them have bursts of distrust. People routinely decide not to follow doctor advice, even though they know they don't have good reasons to do so. Even those exposed to thorough research on how romantic instincts are not long-lasting follow their heart when choosing spouses.
These observations lead me to suspect that people simply have an innate preference to take matters into their own hands. Is there research that can speak to this conjecture?

This is called the illusion of control:

... the tendency for people to overestimate their ability to control
events; for example, it occurs when someone feels a sense of control
over outcomes that they demonstrably do not influence.

Some examples from the same source:

Subjects are either given tickets at random or allowed to choose their
own. They can then trade their tickets for others with a higher chance
of paying out. Subjects who had chosen their own ticket were more
reluctant to part with it. ... Participants who chose their own
numbers were less likely to trade their ticket even for one in a game
with better odds.
On average, drivers regard accidents as much less likely in
"high-control" situations, such as when they are driving, than in
"low-control" situations, such as when they are in the passenger seat.
They also rate a high-control accident, such as driving into the car
in front, as much less likely than a low-control accident such as
being hit from behind by another driver.

The illusion of control is one of several positive illusions that people have about themselves.


Excitement level in OCEAN model So, I would like to know what facet regulates these behaviours / cahracteristics of a person:

How loud and fast-talking they are (on average).
Their excitement level (on average).

Excitement seeking (1) (2) (3) (4) is defined as facet that tells how much a person seeks excitement, but does it tells how much a person is excited on average? And if not then what facet tells that?

It sounds like an aspect of extraversion. I.e., loud and fast talking sounds like gregariousness and assertiveness.  In general, extraverts are also more active and expressive.
For example, the NEO-PI-R has facets of extraversion as follows:
(E1) Warmth (E2)
Gregariousness (E3) Assertiveness (E4) Activity (E5)
Excitement-Seeking (E6) Positive Emotions
Fast talking might also be linked to intelligence.


Is there a complete cortico-cortical connectivity map based on a useful partitioning of the cortex? I have something like Brodmann Areas in mind, but any complete list of cortex regions would do. I'm primarily interested in human brains here. Ultimately I'd like enough information to be able to build an NxN matrix containing boolean "innervates" entries. Numbers representing an "innervation strength" would be great too.

Yes-- you may be very interested in the Human Connectome Project (also here), whose goal is to map human brain connectivity.

One of the primary tools used to map functional and anatomical connections is diffusion tensor imaging (DTI). Unlike the more often used T2-weighted images, DTI allows researchers to image white matter tracts directly.

The data from the HCP is available for free to researchers, but you need to apply for access. See their website for details.


Using IT to quickly make a simulated brain First of all, I would like to say that I know nothing about cognitive sciences. I am just posting this question because it interested me and I stumbled across this group in stack exchange.

I was recently speaking to a cognitive scientist who had just finished modelling a certain function of the brain for his thesis (using a simulation program).

He soon told me that this can be done because the neurons are an analogue system and this analogue system can be modeled using math (like any analogue system that I know of).

My first question was:
Does his task in "modelling the neurons" have a fixed set of rules or steps logical that he follows.

He said that there are clearly defined rules even though many rules are still undefined.

Then my second question was:
Could it be possible to automate the task of "modelling the neurons" (using IT) in order to make larger systems more quickly and to test the disputable arguments more quickly.

Now my question to the forum is:
Is this a realistic approach and has anyone here already tried to do this? Before waving it aside please consider the fact that IT has been used to develop software that can solve complex problems. Ie. Mathematica, Sage, Matlab etc..

I am aware that it is much more complicated than math, but if it is possible to define rules it should also be possible to apply those rules automatically...

I'm sorry if I used bad or confusing terminology. I have no clue about this field and I am just asking out of curiosity..

This is an incredibly broad question, but I admire your spark of curiosity so I'm going to give you a quick answer anyways.

Firstly, there is no defined steps for modelling parts of the brain. The laboratory I was a member of created Spaun. Spaun is the world's largest functioning brain model and uses biologically plausible neurons as the foundation for it's computation. The methodology for creating the most recent iteration of this model varies wildly from part-to-part. The vision system was adapted from Deep Learning Convolutional Neural Networks, the basal-ganglia and thalamus came from an anatomical model and the working-memory model came from engineering analysis of dynamical systems. None of these could have come from evolutionary algorithms or any other sort of algorithm known to humanity at this point.

Another way of modelling the brain (mostly the human behaviour part of it) is ACT-R, which doesn't use neurons at all. Once again, there's no algorithm for evolving this system and interestingly it's the foundation behind a lot of the intelligent systems you mentioned.

The search for evolution and learning methods for groups to gain intelligence is generally called Artificial Life (ALife).

You'll notice that there's a bunch of different levels to approach the problem of modelling the brain. Your friend was at the biological bottom-up level, ACT-R is at the behavioural top-down level and Spaun is the weird hybrid. Although all of these systems use IT in some way (Spaun was built with a Python library called Nengo, ACT-R is written in LISP), the processes for creating these systems cannot be automated and would require the creation of a general artificial intelligence.


What are the reasons behind monogamy in humans? What makes human being in anger or in mental pain once his/her partner leaves? If you think logically we can replace our partner with a new one or if alone also doesn't make any difference.

From another perspective a person having multiple partner increases the chance of having better and more offspring, so by evolution this should be a happy emotion than a sad one.

So my question is why is infidelity bad and not a good thing.

First off, I think monogamy is a socially and culturally determined construct in man.

In the animal world both monogamy and polygamy are encountered. Monogamy increases the chance of the survival of individual offspring, as dad can help raising the offspring  and can defend the family. This increases fitness.

On the on the other hand, polygamy increases the spread of the (male) genes and hence increases the chance that the male gene pool is spread.

The relative benefits of both strategies depends on many factors, including resource availability, offspring need, parental care, and mating dynamics (Klug, 2018).

Reference
- Klug, Front Ecol Evol (2018); 2018.00030


Has there been any studies of pathological "nomad-ness"? I've spent some time trying to search for this but my lack of knowledge limits my ability to find any information about this subject.

I know someone who constantly sees another city as a "Grass is Greener" and will pack up and move about every eight months. This behavior of "loose-footing" that I'm trying to describe meets the 4 D's of Psychopathology:

Deviance: Moving to another town for an unacceptably bad reason that someone of their intelligence wouldn't accept if they heard it from someone else.
Distress: Forgoing valuable social and capital assets that causes hardship after the move. Feelings of loneliness after losing touch of newly created friendships before the move. Constant anxiety of not moving to a new city when they think they find a better one.
Dysfunctional: The person is in complete denial of the behavior trend and after moving to a new city will spend resources in material or non material assets that reflect an intention to not move again. Like signing a two-year lease or selling or buying a car or a city parking space. Or quitting a Top-100 University after two years and a 4.0GPA in engineering that gave them a full-ride, because of a unacceptably poor reason.
Danger: These self-imposed hardships give the person chronic depression and a danger to harm themselves.

I'm only talking about this when it is pathological. I am assuming this is common, but I'm unsure of how common it is as I can't find any info about it. Hence the motivation for the  question.  I'm not referring to a cultural group or a nomad as being pathological.

One could say that this is just depression and/or anxiety and while that is true. I would imagine that this behavior is unique or common enough to deserve its own study of this trend, its origins or treatment strategies. For example growing up with derelict parents or maybe moving too often during childhood.

Although not a clinical diagnosis for mental disorder, the term Residential Instability brings up many articles discussing psychological problems associated with it in Google and Google Scholar.

Cotton, B. P. & Schwartz-Barcott, D. (2016). Residential Instability Among Low-Income Families: A Concept Analysis. Archives of Psychiatric Nursing 30(2): 257-261. doi: 10.1016/j.apnu.2015.11.006 pmid: 26992880
Residential instability is relatively common among low-income families and is associated with a host of negative outcomes, especially for children and adolescents. Psychiatric nurses, especially those in the advanced practice role, observe the consequences of residential instability within the clinical setting. Yet, to-date, the concept is somewhat vague and its essential meaning and definition remain unclear.


How exactly do "you" think and interact with your body? It has been established that our brains control many processes that your body carries out autonomously and involuntarily. However, other actions are controlled by you. (e.g. you lift an arm, you walk). Those are not things that the brain manages without you being aware of it. How does a person communicate with their brain to give commands to rest of the body? Essentially, if I'm wording it correctly: what is the difference between the brain's involuntary motor tasks and consciously managed motor tasks.

You have asked an excellent question. However, this innocently short question involves many dimensions: the philosophical discussion of consciousness, the neurobiological basis of motor movements, reflexive actions, relationship between sensory and motor areas in the brain etc. I'll try my best to elaborate on my answer: meanwhile, your best bet would be to search the term "Control Consciousness" online.

Here is an extract that may (if you can navigate through jargon) help guide you in the right direction. Note that the author is trying to argue for the position that the difference between conscious and unconscious motor tasks depends on the hierarchy of the motor cortex:

Terms:

Allocentric-Egocentric: Allocentric refers to being linked to a reference frame based on the external environment and independent of one's current location in it. For example, giving the direction as "north," as opposed to "right" (which would be egocentric).

  The main idea of ‘‘directness’’ here means something like ‘‘not
  mediated by sensory inputs or imagery thereof.’’ To illustrate, even
  on the sensory theory, motor commands have an indirect influence: I
  turn my head and thus see something other than what I was looking at.
  But here the changes exerted on the conscious state by the motor
  command are mediated by changes in sensory input. If motor commands
  themselves or copies of motor commands - so-called efference
  copies — can make a difference on conscious states without the
  difference being mediated by changes caused to sensory inputs, then
  this would be an instance of the influence of motor commands being
  direct. As stated, the most basic form of the theory is inadequate for
  distinguishing conscious from unconscious control states. Not just any
  contribution from motor commands will make a contribution to
  consciousness. This is especially evident in the case of unconscious
  control states. What is needed, then, is a means for distinguishing
  conscious control states from unconscious control states. And here an
  extension of AEI can do the trick. The applicability of AEI to motor
  systems looks to be a straightforward affair. First, motor systems are
  arranged hierarchically in much the same manner as sensory systems,
  with the highest levels being most remote (in terms of intervening
  connections) from the periphery of the nervous system. Focusing here
  just on cortex, the highest level is in the prefrontal cortex, the
  lowest level is in the primary motor cortex, and intermediate is in
  the premotor cortex. Further, there exist both forward projections and
  back projections between successive levels of the motor hierarchy
  (Churchland, 2002, p. 72). We may further characterize levels in the
  motor hierarchy as differing along an allocentric-egocentric
  dimension. To illustrate, a high-level motor representation may have
  an abstract content such as 'Grab a coffee mug' - a content that abstracts
  away from low-level egocentric details about the precise sets of
  muscular contractions required to get the job done. The most specific
  details will be the task of motor representations at the lowest levels
  of the motor hierarchy.

Sources:

Control Consciousness
Pete Mandik
Topics in Cognitive Science 2 (2010) 643–657

Brain-wise: Studies in neurophilosophy.
Churchland, P. S.
(2002). Cambridge, MA: MIT Press.

Additional Reading:

Consciousness of action., The Blackwell companion to consciousness (pp. 540–550).
Jeannerod, M. (2007). M. Velmans & S. Schneider (Eds.)
Oxford, England: Blackwell.


How to calculate composite factor scores post factor analysis for a questionnaire? I have a question with regard to calculating composite factor scores after running a factor analysis in SPSS. My research is on work related stress and I collected my data through a perceived stress questionnaire. I check for reliability for all sub scales and ran a factor analysis and obtained a clean factor solution extracting four factors. Each factor consists of 5-6 items.

How do I calculate the totals for each factor?
Should I calculate the scores before or after centering the data?

Typically, questionnaires where all items are on the same response scale are coded differently to composite variables where you have variables on different metrics (e.g., a set of ability tests).

Sums and means: For questionnaires like yours, you would commonly just take the mean or the sum of items that belong to a given subscale (note that you may need to first reverse code some of the items). I have a few notes here about doing this in SPSS and R. I generally prefer this method: (a) it's simpler; (b) it's easy to compare scores across studies; (c) it doesn't force orthogonality or require choices about degree of correlation between factors, rather it is determined by item content; (d) by using the mean, you get values that are on the same scale as the original response scale.

Test manual: More generally, assuming the test has been used before, you should examine the test manual or other published studies to see how the test is intended to be scored. By following these instructions, you will make your results more comparable to other studies that have used the test.

Factor saved scores: There is also an argument for using factor saved scores.
If you do that, there are various methods for deriving scores from a factor analysis. Your software will often provide various means for extracting factor saved scores with various properties. You can also save the coefficients from the factor coefficients table. You can then compute your own factor saved scores by multiplying the coefficients for a given factor by the scores for a particular individual.

Centering: All the above methods (sum, mean, factor saved scores) are examples of weighted composites (i.e., $y_i = \beta_1 x_{i1} + \beta_2 x_{i2} + ... + \beta_p x_{ip}$ for participant $i$ where there are $p$ items, $x$ is the response, and $\beta$ is the weight and where $y$ is one subscale score; you could add another index for multiple subscales). Centering only changes the mean of such a subscale. If you were to create two scales scores, one with centered variables, and one without, the two scale scores would be perfectly correlated. Note that rescaling (e.g., creating z-scores) does make a difference, and is often appropriate where items are on different metrics.

I agree with @Damien's answer that the DiStefano (2009) reference is a good place to get an overview of the issues.

References

DiStefano, C., Zhu, M., & Mindrila, D. (2009). Understanding and using factor scores: Considerations for the applied researcher. Practical Assessment, Research & Evaluation, 14(20), 1-11. PDF


Is "haptodysphoria" an urban legend or is there another term under which this studied? I was googling for something like why some people don't like to touch velvet, and the top hit was https://en.wiktionary.org/wiki/haptodysphoria where it's defined as

  An odd, disagreeable sensation felt by certain people when handling peaches, velvet or other fuzzy surfaces.

but there are zero hits on that term in pubmed. So is this phenomenon of dislinking to touch some materials something more seriously studied under some other terminology?

Apparently "sensory over-responsivity" is a more widely used term:

  Sensory over-responsivity, a subtype of sensory modulation disorder, is characterized by extreme negative reactions to normative sensory experiences. Individuals vary widely in their reactions to sensory stimuli, with some children and adults reporting aversive, even painful, responses to contact with everyday objects and exposure to everyday sounds. Some people find the sound of vacuum cleaners or sirens highly aversive, and some children fuss about stiff new clothes and labels sewn inside collars. They may dislike being lightly touched or vigorously protest brushing their teeth.

No mention of velvet though in that article.


How are personality traits "encoded" in the brain? How are personality traits – such as optimism, sensation seeking or need for cognition – "encoded" in the brain?

Do people with different levels of, say, extraversion have different neuronal structures? Or do they have different amounts of certain neurochemicals, different numbers of receptors, or other kinds of functional differences?

So if you want to change a trait, can you simply stimulate or supplement neuronal functionality, e.g. by administering the lacking neurochemicals, or do you have to "destroy" and "rebuild" the neuronal structure, e.g. through learning?

Cool question...really huge though. I'll have to revisit this as I find time to add more. For starters, I just saw an interesting link in @ForbiddenOverseer's question, "Are there any personality theories that use the scientific method?" For some info on cerebral blood flow and extraversion, check out Johnson and colleagues (1999). Here's an excerpt of the abstract:

  RESULTS: Overall, introversion was associated with increased blood flow in the frontal lobes and in the anterior thalamus. Regions in the anterior cingulate gyrus, the temporal lobes, and the posterior thalamus were found to be correlated with extraversion. CONCLUSIONS: The findings of the study lend support to the notion that introversion is associated with increased activity in frontal lobe regions. Moreover, the study suggests that individual differences in introversion and extraversion are related to differences in a fronto-striato-thalamic circuit.

In an earlier answer today (to What makes a sight or an image mesmerizing and irresistible?), I implied that sensation-seeking relates to the behavioral activation system, the nucleus accumbens and VTA, and dopamine. Support for those relationships ought to be available through Wikipedia.

Here's a summary of other info from my lecture on biopsych for my class on personality a few years ago:

Frontal lobe

Activity has been correlated to negative emotionality via fMRI.
Cooperative people show more activity during social interaction, implicating reward sensitivity.
Aversive attention and motivation is right lateralized; approach motivation and aversion inhibition is left lateralized.
Transcranial magnetic stimulation (TMS) knocks out self-enhancement bias temporarily.
Damage reduces emotional experience, regulation, and inhibition – cf. Phineas Gage, Capgras syndrome, and the history of frontal lobotomies.

Amygdala

Implicated in identification of rewards & threats

Activates in extraverts receiving pleasant stimuli (e.g., happy faces, scenes, & emotion words; pleasant tastes)
Activates during social attraction; generates sexual responsiveness
Activates in shy people viewing unfamiliar faces
Also in pessimists when shown a picture of a snake
Overactive in people with anxiety disorders such as PTSD

Activated by unexpected emotional conflict – stronger in neurotics viewing conflicting cues.
Inhibited by anterior cingulate – cf. brain tumor in Charles Whitman, UT tower sniper ’66

“I have been a victim of many unusual and irrational thoughts.  These thoughts constantly recur, and it requires a tremendous mental effort to concentrate on useful and productive tasks.”

Ascending reticular activating system – acts like a valve on incoming stimulation

More “wide open” (active) in introverts

Stronger reaction to lemon juice stimulus
Faster responses to noises in brainstem via EEG

Reaction to erotica, violence, mutilation, insects, etc.:

High sensation-seeking: arousal and reward area activation
Low sensation-seeking: emotional self-control area activation

Electrode stimulation of substantia nigra $\rightarrow$ depression!
Governs reactivity, not baseline arousal

Optimal arousal threshold is the same distance from rest regardless of extraversion
ARAS affects acceleration from stimulation toward the threshold. See simplistic figure:

I've got a few answers here on neurotransmitters and hormones already:

Testosterone affects aggression, competitiveness, sexual motivation, sensation-seeking, risk aversion, empathy, and abstract reasoning. See "Are there recent theories on physiognomy?" and "What are the cognitive effects of increasing testosterone levels in men?"
Monoamine oxidase A affects maladaptive vulnerability to stress resulting in antisocial behavior. Mu-opioid receptors relate to collectivism and pain sensitivity. Serotonin also relates to collectivism and anxiety. See "Innate personality tests: do they exist? If not, why?"

Judging from effects of TMS (and tDCS), intelligence may relate to cortical excitability and myelination – see "Can learning be facilitated by transcranial magnetic stimulation?" As for changing personality in general, neuroplasticity may be important to consider, but biofeedback may be able to take advantage of it to alter neuroticism – see "Neuroplasticity and Treatment of Depression". Chronic malnutrition might even affect neuroticism by deeper mechanisms than subjective stress resulting directly from deprivation – see "The effect of proper food intake on emotions and brain function". Other links seem to exist between physical and mental well-being – see "Does mental satisfaction lead to physical satisfaction?" – but I'm probably getting further afield here than you intended answers to go.

Reference
- Johnson, D. L., Wiebe, J. S., Gold, S. M., Andreasen, N. C., Hichwa, R. D., Watkins, G. L., & Ponto, L. L. B. (1999). Cerebral blood flow and personality: A positron emission tomography study. American Journal of Psychiatry, 156(2), 252–257. Retrieved from http://journals.psychiatryonline.org/article.aspx?articleid=173270.


What is the standard error of measurement for teacher made multiple choice tests? Assume a teacher constructs a four-choice multiple choice test. Each item has only one correct response. The test is scored from 0 to 100 representing the percentage of items answered correctly.

I want to have some rules of thumb that could be informative regarding how many items are required to achieve a given standard error of measurement. For example, it would be nice to be able to advice teachers who write their own multiple choice exams "if you have 100 items that are reasonably well worded, you can expect a standard error of measurement of 2.5".

The standard error of measurement is often defined as:

$$s_e=s_x \sqrt{1-r_{xx}}$$

where $s_x$ is the standard deviation and $r_{xx}$ is the reliability.

Furthermore internal consistency reliability can be calculated from the number of items $k$ and the mean inter-item correlation $\bar{r}_{ij}$ (i.e., average correlation between item $i$ and item $j$ for all $k$ items where $i\neq j$):

$$r_{xx}=\frac{k(\bar{r}_{ij})}
{1 + (k -1) \bar{r}_{ij}}$$

However, I'm wanting to translate the above information into meaningful recommendations for teachers. Thus, this assumes that I have some empirical estimate of typical values of $\bar{r}_{ij}$ and that I have an estimate of $s_x$. It then requires application of the formulas to calculate standard errors of measurement for likely numbers of items $k$. In particular, I was thinking about numbers of items equal to: 10, 20, 50, 80, 100, 120, 150, and 200.

Thus, I was wondering whether there are any published estimates of the standard error of measurement teacher constructed multiple choice tests.

Harvill mentions an estimate by Lord (1959). Lord (1959) presents some data for the standard error of measurement for some moderately difficult cognitive measures. While there are many caveats (e.g., the estimate of the standard error is most accurate for scores around 50% and the estimates are based on tests that are neither particularly easy or particularly difficult with means in the .35 to .75 range), Lord provides a simple formula that can be used as a rule of thumb for predicting standard error of measurement in his sample of cognitive measures which performed quite well.

$$\hat{s}_e = .432 \sqrt{k}$$

where $k$ is the number of items.
Alternatively, if you are interested in the mean correct on a 0 to 100 scale rather than the total correct, you can divide by $k$ and multiply by 100.

$$\hat{s}_e = \frac{.432 \sqrt{k}}{k} \times 100$$

When I plugged this into R for some sample values I obtained:

> lord_approximation <- function(k) 0.432 * sqrt(k) /k * 100
> k <- c(10, 20, 50, 80, 100, 120, 150, 200)
> cbind(k, sem=round(lord_approximation(k), 2))
       k   sem
[1,]  10 13.66
[2,]  20  9.66
[3,]  50  6.11
[4,]  80  4.83
[5,] 100  4.32
[6,] 120  3.94
[7,] 150  3.53
[8,] 200  3.05

Of course, not all of this reduction in standard error of measurement is due to greater accuracy. Some of it comes from the smaller standard deviation in true scores that occurs when you take the mean of more items. Furthermore, these estimates are based on relatively well designed cognitive measures. Teacher designed tests may have slightly lower reliability and thus larger SEM.

References

Harvill, L. M. (1991). Standard error of measurement. Educational Measurement: Issues and Practice, 10(2), 33-41. PDF
Lord, F. M. (1959). Tests of the same length do have the same standard
error of measurement. Educational and Psychological Measurement, 19, 233-239.


How to read a neuron tuning curve graph? I'm working through the tutorial of section 2.4 of "How to Build a Brain" and I've encountered this graph of a neuron tuning curve.

I understand the Y axis is the firing rate of the neuron, that each curve is the response of a single neuron (there are 100 neurons represented here) and that this plot shows a variety of "on" and "off" neurons, but what does the X axis represent? Is it the action potential input? Is X the value that the neuron represents by firing at that rate?

Please allow me to give some context around the tutorial. You first create a population of 100 neurons to represent an input that will vary from -1 to 1. You notice that this works well, but that the representation degrades when you exceed this range falls apart and you cannot represent anything the range past -2 to 2.

You then use a new population of neurons to build upon this newly acquired knowledge of how neurons can represent functions, to make them represent a 2-dimensional vector similar to the monkey-arm motor experiment performed by Georgopolous.

I could take the leap of faith here and just take for granted that neurons can represent functions and that the more neurons you have, the better approximation of the function you can get, but I feel like understanding these fundamental concepts are important.

From the comments:

I'm going to hazard a guess that these are neurons that are tuned to a particular direction in space and that the x-axis is the angle in multiples of π radians, particularly since these are related to the work of Georgopoulos and colleagues.

Since we know these are positionally tuned neurons, you can see some other examples in
this Wikipedia page for some other examples.

  A typical population code involves neurons with a Gaussian tuning curve whose means vary linearly with the stimulus intensity, meaning that the neuron responds most strongly (in terms of spikes per second) to a stimulus near the mean.

So, as mentioned above, the independent variable here is the stimulus "intensity" (in this case abstracted by the quantity of direction) and the firing rate is the dependent variable, hence their positions on the axes in the plot.

For some of the more theoretical studies of this type of phenomenon, I would definitely check out the work of Emo Todorov, among many others, as well.


Is there a term in psychology for when a tool is perceived as an extension of your body? Is there a specific term that describes the phenomenon where you perceive a tool as an extension of your own body?
An example of this would be when a skilled artist or tradesman has so mastered their craft that when they use a paint brush or wrench their mind extends their consciousness to the object and they use the tool unconsciously.
Another example is riding a bicycle.  If you are an experienced cyclist, you are usually not consciously thinking about how you are riding your bicycle.  Your mental awareness has expanded to the bicycle and you respond to riding it like it is another limb of your own body

Short answer
Possible interesting terms are:

distal attribution (externalization)
body transfer illusion (rubber hand illusion)
embodiment

Background
This is a very interesting, yet difficult question. I have come up with a few items that may (or may not) be of interest.
Firstly, there is distal attribution, also referred to as externalization. It is defined by Loomis as:

...[the phenomenon] that most of our perceptual experience, though originating with stimulation of our sense organs, is referred to external space beyond the limits of the sensory organs

and by Auvrey at al. (2006) as:

[the] ability to attribute the cause of our proximal sensory stimulation to an exterior and distinct object

Distal attribution occurs for instance in sensory substitution. Sensory substitution refers to the process of substituting one (dysfunctional) sense with another. A classic example being the guide cane. After training and prolonged use, blind people are reported to experience the information not by haptic feedback perceived in the hands via the cane, but to experience the tactile feedback at the tip of the cane instead. Thus they externalize, or distally attribute the tactile feedback in the hand as originating from the tip of the cane.
Another interesting phenomenon that may relate to your question is the body transfer illusion, or the rubber hand illusion (Ehrsson et al., 2005), from Wikipedia:

The [study participants] saw a lifelike rubber left hand in front of them. The experimenters stroked both the subjects hidden left hand and the visible rubber hand with a paintbrush. The experiment showed that if the two hands were stroked synchronously and in the same direction, the subjects began to experience the rubber hand as their own. When
asked to use their right hand to point to their left hand, most of the time they pointed toward the rubber hand.

In other words, after some accommodation, the study participants attributed sensory input to their real hand to the fake arm in their visual field.
Thirdly, and lastly there is (prosthesis) embodiment (Engdahl et al., 2020), i.e.,

the perception of a prosthesis as part of one’s body

This refers to the phenomenon, akin to sensory substitution but in a physically more invasive context and not exclusively related to sensory perception, that  implanted prosthetics become experienced as a part of the body. It is a more complicated issue than externalization as discussed above, and is especially important during rehab where acceptance is an important part of the process. Embodiment comprises at least two processes, namely:

An object may be implicitly embodied if some of its properties are processed in the same way as the properties of one’s own body [...]. Embodiment may also be experienced more explicitly, as evidenced by affective reactions towards the object, perceptions of ownership, and other subjective feelings.

To conclude with a fourth term used in a more popular sense, it's often said from experienced car drivers that (Urry, 2004):

The car becomes an extension of the driver's body

So extension may also be terminology that might be useful, yet it doesn't really harbor any mechanistical explanation as to the why or how this happens.
References
- Auvrey et al., J Integr Neurosci (2005); 4(4): 505–21
- Ehrsson et al., J Neurosci (2005); 25(45): 10564 –73
- Engdahl et al., Sci Rep (2020); 10: 15471
- Urry, Theory Culture Soc (2004); 21(4-5): 25-39


What is the most effective treatment for ADD and ADHD that excludes chemical prescriptions from a doctor? Besides chemical medications that are prescribed that can increase the level of dopamine, and other important neurotransmitters in the brain. What is the most effective natural treatment method for ADD, and ADHD?

Not much seems to work; psychotherapy appears questionable when the patients are re-evaluated by someone else. The only thing with a minor but generally applicable effect is free fatty acid supplementation, although the effect may be so minor as to have no clinical value.
Of course, most of these findings come from a meta-analysis (Sonuga-Barke 2013) published in a psychiatry journal...

Two different analyses were performed. When the outcome measure was based on ADHD assessments by raters closest to the therapeutic setting, all dietary (standardized mean differences=0.21-0.48) and psychological (standardized mean differences=0.40-0.64) treatments produced statistically significant effects. However, when the best probably blinded assessment was employed, effects remained significant for free fatty acid supplementation (standardized mean difference=0.16) and artificial food color exclusion (standardized mean difference=0.42) but were substantially attenuated to nonsignificant levels for other treatments.
CONCLUSIONS:
Free fatty acid supplementation produced small but significant reductions in ADHD symptoms even with probably blinded assessments, although the clinical significance of these effects remains to be determined. Artificial food color exclusion produced larger effects but often in individuals selected for food sensitivities. Better evidence for efficacy from blinded assessments is required for behavioral interventions, neurofeedback, cognitive training, and restricted elimination diets before they can be supported as treatments for core ADHD symptoms.

The editorial that accompanied this paper had this pull-out:

Behavioral treatments have been
demonstrated to be helpful for children
with co-occurring disorders and
symptoms, although this blinded
analysis did not show efficacy for core
ADHD symptoms.

And it's worded that way because a prior meta-analysis (Fabiano 2009) using less stringent criteria (no blinging required) found (of course) that behavioral interventions work.
Regarding food colorants, only about 8% of ADHD children are estimated by a different meta-analysis (Nigg 2012) to be affected/sensitive.
And a meta-analysis of diet interventions Pelsser 2017 was quite skeptical of most stuff:

Considering the small average ESs [effect size] PUFA [poly-unsaturated fatty acid] supplementation is unlikely to provide a tangible contribution to ADHD treatment, while further research is required for AFC [artificial food color] elimination before advising this intervention as ADHD treatment. The average FFD [Few Foods Diets] ES is substantial, offering treatment opportunities in subgroups of children with ADHD not responding to or too young for medication.

So the cool new thing is FFD now. Since the last paper is freely available... I won't say much more, except that it may take a year to permute food choices until the right few foods are determined. They do say in the (body of the) paper that (owing to this time-scale issue):

large-scale implementation of the few-foods approach would not be a realistic recommendation.

I have to wonder why that didn't make it into the abstract.


Why does your recorded or objective voice sound different to what you hear in your own head? When speaking, I hear my own voice very differently from how others do and from what it really is. The sound differs in tone, pitch, volume, etc. For example, recordings of my singing or speaking in foreign languages sounded a lot worse than what I heard in my own head.

Is that a popular phenomenon? Or is that a "syndrome", and which parts of sensation and perception are unusual? Last, is it modifiable?

Jens' answer is pretty much spot on, but misses the fact, remembered from my undergraduate lectures, that your ears actually partially 'turn off' when you speak (or chew), in what's called the stapedius reflex (wikipedia).
The most common reference I've seen for this is Møller (2000), which unfortunately is a book, but I'm sure more information could be found with a little digging.
Reference
Møller, Aage (2000). Hearing: It's Physiology and Pathophysiology (illustrated ed.). Academic Press. pp. 181–90.


Can the neurological damage done by alcohol be reversed? I read online that heavy alcohol consumption can lead to neurological damage, specifically in areas that affect your cognitive performance and memory but what I couldn’t find is if the damage can be reversed.

https://www.verywellmind.com/alcohol-damages-day-to-day-memory-function-62982

https://www.addictioncampuses.com/blog/alcohol-abuse-cause-brain-damage/

Most of the acute neurological effects of ethanol alcohol, such as slurred speech, ataxia, and confusion/sedation, are reversible, and the symptoms will disappear after the blood alcohol level gets down to below the intoxication level. However, in very high dose, alcohol can cause stupor or even coma, with irreversible neurological damages from associated hypoglycemia (from the hypoglycemic effect of alcohol and from concomitantly inadequate food intake) or hypoxemia (from the respiratory depression effect of alcohol). Also, there can be indirect permanent brain damage from falls, car accidents, regurgitation with aspirations, drowning, etc.

Most of the chronic neurological effects of ethanol alcohol, such as Wernicke-Kosakoff syndrome, alcoholic cerebellar degeneration, and alcoholic dementia are irreversible, and at present, there are no effective treatments to reverse neurological damage in these conditions. However, further progression can be halted by quit drinking alcohol. And, in the case of Wernicke’s encephalopathy,  if adequate dose of thiamine is given in time, neurological injuries can be reversed and permanent neurological damage may not occur.

General References.

Healthline. Alcohol-Related Neurologic Disease

Wikipedia. Alcohol intoxication

Wikipedia. Wernicke-Korsakoff syndrome

Academic References.

Arts NJM, Walvoort SJW, Kessels RPC. Korsakoff’s syndrome: a critical review. Neuropsychiatr Dis Treat. 2017; 13: 2875–2890. doi: 10.2147/NDT.S130078

Harper C. The Neuropathology of Alcohol-Related Brain Damage. Alcohol and Alcoholism. 2009 Mar-Apr; 44(2):136–140. https://doi.org/10.1093/alcalc/agn102

Ridley NJ, Draper B, Withall A.Alcohol-related dementia: an update of the evidence. Alzheimers Res Ther. 2013; 5(1): 3. doi:10.1186/alzrt157


Voltage sensitive dyes technique: 2-photons microscopy vs confocal microscopy I just discovered voltage sensitive dyes technique and I was wondering what would be the advantage to use 2-photons microscopy compared to confocal microscopy?

They are both fluorescent techniques which can measure photon's emission, in most of the cases it looks like 2-photons microscopy is preferred over confocal microscopy, but why is that?

Confocal Fluorescence Microscopy and 2-photon Fluorescence Microscopy are two techniques commonly used in neuroscience to image only one plane of the sample and thus increase resolution. However, how they achieve this technically is  distinct.

Confocal  (confocal laser scanning microscopy (CLSM))
In confocal microscopy the sample is scanned with a laser in X and Y coordinates and fluorescence is recovered by de-scanning the emitted photons. To select photons emitted only in the imaging plane (focal plane), a pin-hole restricts the collection of the emitted light allowing only the passage of photons emitted in the plane one is currently imaging.

This image exemplifies how emitted photons (dashed red beam) originating outside of the focal plane will be blocked by the pinhole before reaching the detector.

This has several consequences

1) The laser light will excite fluorophore which you are not imaging (because the emitted photons are blocked by the pinhole). This bleaches your sample below and above your imaging plane while you are not collecting information from those planes.

2) The emission path has to be de-scanned in order for the pinhole to work. This long path from the emission to the detection of the emission photons means that you are loosing some precious emission photos.

2-photon Scanning Laser Microscopy

In the case of confocal microscopy excitation is achieved by the acceptance of 1 high energy photon. However, in 2-photon microscopy, two photons of half the energy are used to excite the fluorophore.

This introduces a non-linearity that has the following immediate consequence : if you need to 2-photons to coincide on the same fluorophore to excite it then you will only excite molecules of flurophore in a small volume of space in which the intensity of the laser is sufficient. Then since the excitation of molecules is limited to a small volume in x,y,z.

This image shows the difference between excitation when done with single photon (left) and 2-photon (right). Black is the areas where the excitation took place. As you can see on the left the single photon excitation excites planes below and above the imaging plane.

Then 3 things happen

1) You can restrict your imaging to a plane without the need of adding a pinhole. In Confocal the pinhole restricts the passage of photons emitted from planes other than the imaging plane. In 2-photon your effective excitation is already restricted in the Z plane, so the emission will also be restricted to this plane.

2) Since you now don't need a pinhole, you don't need to de-scan the emission. This means you can put your detector (Photon Multiplier Tube: PMT) very close to where the emission happens. Now you want all the photons you can get, because they all come from your image plane!

3) You are not bleaching other Z planes of your sample, because the intensity in other planes is not enough so that 2 photons excite the fluorophores.