# Question
Title: What are the benefits of using all 30 personality facets in multiple regressions compared to just including hypothesised facets?
What are the advantages/disadvantages of using all 30 facets (NEO PI-R; Costa & McCrae, 1992) in a multiple regression versus only using the facets that you have a hypothesis for?

I see that the vast majority of research always includes all 30 facets, but I don't quite understand the added value of this.

**References**

Costa, P. T., Jr., & McCrae, R. R. (1992). *Revised NEO personality inventory (NEO PI-R™) and NEO five-factor inventory (NEO-FFI): Professional manual*. Odessa, FL: Psychological Assessment Resources.

# Answer
> 5 votes
I wrote a paper that focuses on this question (Anglim & Grant, 2014; pre-print is https://osf.io/g8kbj/download).

In short, if you're interested in estimating how well facets predict an outcome, then you should include all facets as predictors. Likewise, if you want to estimate the incremental prediction of facets over domains (e.g., 30 facets over the Big 5), then you should include all domains in the domain regression model and all facets in the facet regression model.

If you're doing research, then presumably, you don't know which facets predict the outcome. Therefore, it's an empirical question which do predict.

An important point is that you use an estimator that corrects for biases when including many predictors. A reasonable approach is to use adjusted r-squared, although when you have 30 facets, large samples help a lot.

I also have more recent primer that is designed to be fairly accessible (Anglim & O'Connor, 2018, see preprint https://psyarxiv.com/a78g2/download )

If you want more detail, post further questions in the comments.

### References

* Anglim, J., & Grant, S. L. (2014). Incremental criterion prediction of personality facets over factors: Obtaining unbiased estimates and confidence intervals. Journal of Research in Personality, 53, 148-157. https://osf.io/g8kbj/download
* Anglim, J., & O'Connor, P. (2018). Measurement and Research Using the Big Five, HEXACO, and Narrow Traits: A Primer for Researchers and Practitioners. Australian Journal of Psychology. https://psyarxiv.com/a78g2/download

---
Tags: personality, statistics
---


# Question
Title: What are the correlation between the Big 5 (OCEAN) dimensions of personality?
I'm looking for quantitative research on the correlation between the five dimensions in OCEAN psychometric models. Would appreciate any references.

# Answer
> 4 votes
My answer to the question on evidence for the GFP provides numerous references on the correlations between the Big 5:

What is the support for a global personality factor?

The key bit of the answer is as follows:

> **van der Linden et al 2010** extend the work of Musek (2007) by presenting a meta-analysis of Big 5 intercorrelation matrices in order to assess the evidence for a General Factor of Personality. Table 2 shows the meta-analytic average scale intercorrelations for the big 5 measures included in the meta-analysis. It shows how across a wide range of measures and measurement procedures, the Big 5 scales moderately intercorrelate. The average absolute unadjusted correlations between the Big Five was 0.23.

You can also check out other work discussing higher-order factors (typically one or two factor models). These imply a correlation between the Big 5.

To quote my own primer on the Big 5 (Anglim & O'Connor, 2018: https://psyarxiv.com/a78g2/download):

> Researchers have posited one and two factor higher-order models of personality suggesting that the Big Five may not be the broadest meaningful level of personality analysis (Anusic, Schimmack, Pinkus, & Lockwood, 2009; Digman, 1997; Musek, 2007; Veselka et al., 2009). Notably, a single, broad factor (termed the General Factor of Personality; GFP) has been proposed to account for meaningful trait variance at the highest level (e.g., Musek, 2007), although see various critical perspectives (Davies et al., 2015; De Vries, 2011; Revelle & Wilt, 2013) .

Thus, you could check out those references for further background on one and two-factor models. Such papers will generally also discuss the structure of correlations between the Big 5 and arguments for and against why they are meaningful.

### References

* Anglim, J., & O'Connor, P. (2018). Measurement and Research Using the Big Five, HEXACO, and Narrow Traits: A Primer for Researchers and Practitioners. Australian Journal of Psychology. https://psyarxiv.com/a78g2/download
* van der Linden, D., te Nijenhuis, J., & Bakker, A. B. (2010). The general factor of personality: A meta-analysis of Big Five intercorrelations and a criterion-related validity study. Journal of Research in Personality, 44(3), 315-327.

---
Tags: measurement, personality
---


# Question
Title: Canonical Literature for "Big 5" Personality Theory
I'm searching for a good reference on "Big 5" personality theory that explains the topic in detail beyond the level of a website. I am hoping to get a pointer to some of the "canonical" literature--i.e. the standard papers/texts/etc. where Big 5 and its connection to factor analysis are presented rigorously.

I would also love a pointer to literature which discusses the psychometric theory underlying the typical Big 5 tests.

# Answer
> 3 votes
I quite like Saucier & Srivastava (2015). They provide a very nice overview of the evidence for different trait models. They give you a good overview of how factor analysis and lexical studies relate to the Big 5.

You can see my own attempt at providing a primer on the Big 5 and trait measurement at Anglim & O'Connor, 2018. You could look at some of the following key references from that paper:

> ... the most influential basis for a Big Five came from Goldberg (1981, 1990) who conducted factor analyses on comprehensive sets of trait adjectives. Over multiple studies Goldberg found support for the “Big Five” factors of personality. Strong support for a five-factor model was also obtained in various studies by McCrae and Costa (1987) who repeatedly found five dimensions across instruments and observers (self and peer- reports). On balance, lexical studies along with studies using large questionnaires tend to support the idea that personality can broadly be described using the Big Five dimensions of personality (Condon, 2017; Costa & McCrae, 1995; Markon, Krueger, & Watson, 2005).

### References

# Answer
> 2 votes
You should consult the BFQ with original copyright in 1993, Organizzazioni Speciali, Florence Italy (most likely with adaptation, editing and new copyright in the country in which you reside). Here you can find the data (for use and application) and the studies on which it is based.

For a work that I had to do I followed the bibliography indicated in this test as well as part of the history of the factors (in capital letters as they appear in BFQ):

ENERGY: Extraversion (Costa and McCrae). Surgency of the Goldberg model (quantity and intensity of interpersonal interactions, in relation to affection, assertiveness, activity and gregarism).

AFFAIRS: Liking (Costa and McCrae). Similar to cordiality vs. hostility (Digman)

MENTAL OPENING: Opening the experience (Costa and McCrae).

No matter what time you have, you will not be able to see the whole story of all the factors, you should close the focus on those that seem more interesting for your study.

---
Tags: reference-request, measurement, personality, big-five
---


# Question
Title: Is there any disease that prevents a person from being angry?
Is there any disease that prevents a person from being angry? As a reference, the resection of the amygdala reduces feelings of fear.

**web links**

# Answer
**Short answer**
Brain damage is typically associated with increased expression of anger and aggressive behavior. I wasn't able to find *any* paper reporting lack of anger expression after brain damage. Great question!

**Background**
Assuming you are after symptoms associated with brain damage, I have put my efforts into writing up an answer on brain trauma and anger. To strat with your example of the amygdala - indeed, removal of the amygdala (amygdalectomy) has been used to treat extreme feelings fear. Damage to the amygdala reults in deficits in facial emotion recognition. Specifically they have impaired recognition of expressions of fear and guilt and trustworthiness. These findings suggest that the amygdala has a critical role in face emotion processing (Elliott *et al*., 2011).

Anger is thought to be mediated by the medial amygdaloidal areas that connect to the medial hypothalamus via the stria terminalis, and from there to the dorsal half of the periaqueductal gray. Aggression (the expression of anger) evoked by stimulation of the amygdala is dependent on the functional integrity of the medial hypothalamus and the periaqueductal gray. However, aggression evoked by stimulation of the periaqueductal gray is not dependent on the functional integrity of the amygdala. The amygdala-hypothalamus-periaqueductal gray is thought to mediate reactive aggression (Blair, 2013).

Hence, it seems that a likely candidate for the obliteration of feelings of anger is the periaqueductal gray. Does damage or removal of this structure reduces feelings of anger? Lesions in this area of the brain have been associated with loss of speech in humans (Esposito *et al*, 1999), reduced fear in rats (Lonstein & Stern, 1997), and upon complete destruction it resulted in a limp inertness in cats (Bailey & Davis, 1943). The Lonstein & Stern (1997) paper reports that

> \[Periaqueductal gray\] lesioned rats **attacked a strange male twice as often** as controls did, which is suggestive of reduced fearfulness. These results extend the known roles of the PAG \[periaqueductal gray\] in \[\] defensive behaviors.

Hence, removal of PAG actually increases aggressive behavior (reduces fear), rather than decreasing aggressive behavior!

In all, I wasn't able to find *any* study that reports on brain damage that results in a reduction of anger expression. Indeed, **brain damage is often related to increased feelings of anger** and there the track record is extensive

<sub>**References**
**-** Bailey & Davis, \*Proc Soc Exp Biol Med (1942); **51**: 305-6
**-** Blair, *Wiley Interdiscip Rev Cogn Sci* (2012); **3**(1): 65–74
**-** Elliott *et al*., *Neuropsychopharmacology* (2011); **36**(1): 153–82
**-** Esposito *et all*., *NeuroReport* (1999); **10**(4): 681–5
**-** Lonstein & Stern, *J* Neurosci (1997); **17**(9): 3364-78</sub>
> 5 votes

---
Tags: neuroscience, emotion, pathology
---


# Question
Title: Are psychology students more neurotic than the general population?
Using the NEO-FFI to measure Big Five personality traits among students from our faculty, we found that students of psychology are more neurotic (*t* = -2.34, *p* = .02) and less open (*t* = 5.98, *p* \< .001) than the general population. Are there published studies that verify these results?

# Answer
> 3 votes
In general, females score higher on neuroticism and psychology students are predominantly female.

In some young adult norms that I've seen in the NEO-PI-3 test manual, females score about two-thirds of a standard deviation higher on neuroticism.

In my experience at the undergraduate level, about 70% to 85% of students are females. For example, in my most recent paper using a third-year Australian undergrad psych sample (n = 393), we had 79% females (Horwood & Anglim, 2018, JHB).

I believe also that neuroticism declines with age ( e.g., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562318/ ) and psychology students as with other university students tend to be 18 to 25 or so.

You'd have to look a little further to see whether there are differences after controlling for age and gender differences; i.e., whether there's a deeper reason for any differences.

---
Tags: personality, big-five
---


# Question
Title: Are studies included in most meta-analyses based on a narrow range of participants?
This question is mostly quoted from *A New Psychology of Women* (2017) by Lips, page 63:

> Finally, and perhaps most importantly, the studies included in most meta-analyses are based on a narrow range of participants (usually young, North American students) and are not reflective of the populations at large--although this limitation tends to be obscured by the combination of many studies into a single analysis (Halpern, 1995).

I mean, this claim is more than 20 years old. Is it true today? Is there a study that examines the demographics of meta-studies at large or something related? If it is true, is this the case for most psychology research, male-female differences or all studies in the social sciences?

# Answer
Hunter and Schmidt offer a a set of procedures to correct range restriction, these are included in many packages based on their meta-analytic methodology, here are some relevant references:

https://pdfs.semanticscholar.org/75e8/97a797dc876b785042dfd8ac4023a5fc85df.pdf http://onlinelibrary.wiley.com/doi/10.1111/peps.12122/abstract https://www.researchgate.net/publication/6644262\_Correcting\_for\_indirect\_range\_restriction\_in\_meta-analysis\_Testing\_a\_new\_meta-analytic\_procedure mypages.iit.edu/~morriss/siop2009/Le09.ppt mypages.iit.edu/~morriss/siop2005/Oswald05.doc https://www.corwin.com/sites/default/files/upm-binaries/5063\_Hunter\_Chapter\_3.pdf https://utsa.influuent.utsystem.edu/en/publications/implications-of-direct-and-indirect-range-restriction-for-meta-an

hth,

larry
> 2 votes

# Answer
Meta-analysis is a tool that is applied across a wide range of disciplines, especially those involving human subjects. In general, meta-analyses aim to sample all relevant studies that have been conducted.

In some fields, the norm is to use undergraduate students (especially psychology students). Many psychology programs have a research participation pool; so for a lot of basic lab based research (e.g., cognitive psychology, social psychology), this represents a convenient sample. Note of course, that other disciplines will use other samples. Organisational psychology researchers often use samples of employees from organisations. Developmental psychologists study children. Social science researchers often rely on large scale panel surveys.

More recently, online samples are becoming particularly popular. This includes online convenience samples as well as paid samples. In particular, Mechanical Turk is particularly popular in the United States, but other platforms such as prolific exist.

In general, the choices that researchers make about sample are driven by many factors:

* convenience/resources
* discipline expectations
* interests in generalisation (some researchers are mainly interested in generalising to their own culture)
* where the researchers have traditionally come are from (e.g., most researchers in psychology come from the U.S., followed by UK/Europe/Australasia)
* relevance of sample to research question (e.g., sometimes a convenience sample is fine; other times you really need a representative sample); in basic science, it's often fine, but if you're doing organisational or clinical research, you'll generally want a relevant org or clinical sample.

So in short, this phenomena is going to vary a lot across research questions. And in some cases it's probably not going to matter much; in other cases it will.

More generally, there is often a trade-off between convenience and rigour. For example, most researchers who measure job performance would love to have a rigorous objective measure of objective performance, but it's much easier to get self-report. So you'll often find that meta-analyses will be summarising studies that have opted for one point on the convenience/rigour trade-off.

Meta-analysts can and do perform moderator analyses if they think a particular factor might be relevant to the meta-analytic finding (e.g., whether the sample are undergraduate students or not).
> 1 votes

---
Tags: reference-request, meta-analysis
---


# Question
Title: Is there anything comparable to the IPIP for IO psychology, work psychology and the like?
The International Personality Item Pool is a public domain collection of over 3000 items and 250 scales.

Is there anything comparable for work psychology and the like?

# Answer
I'm not aware of any such initiatives. But it would be great to see.

In general, I think I/O psychology has been a bit less proactive in engaging with the open science approach than some disciplines of psychology. More generally, many researchers are silent on the issue of licences for their scales. Thus, it can be ambiguous about what you are allowed to do with a scale, say, that you find in a published journal article. Furthermore, many scales in organisational psychology are explicitly free to use for research purposes are not free for commercial purposes.
> 3 votes

---
Tags: measurement, methodology, io-psychology
---


# Question
Title: Is there an explanation for concepts or situations that are repeated within a short amount of time?
I know that the title is not really clear. That's because I don't know what i'm searching for, unfortunately. Let me explain with an example: Yesterday i was watching a youtube video , more precisely a lecture from MIT. Looking through the comments i found out that the professor from that lecture studied computer science at the University of Waterloo. I have never heard about the University of Waterloo before (until yesterday). Today, while checking my emails i was surprised to see that i got a suggestion to read an answer to a question : "How valuable is the University of Waterloo's computer science program? " I know that with computers may not be so mysterious since they know what content we see on the internet and may use it for making suggestions. The thing is that these kind of situations occur really often even without technological "help".

For example: Some time ago my sister told me about neutron stars. It was fascinating. The next day, during a lecture, my physics professor used neutron stars as an example for a problem.

I had never heard about neutron stars before my sister told me about them and i was shocked to hear my professor that day. I haven't heard about those stars since then.

Or even everyday things: there is a song you didn't listen to for a very long time. Let's say a year. One day you think about that song. Some hours later you hear it playing randomly in a tv show you are watching.

My question is : do these situations have a name ? It happens so often that i already gave it a name but i would like to know if there is some official version

Do they have an explanation from a psychological point of view or they are just fortunate coincidences?

# Answer
> 3 votes
**Short answer**
The repeated encounter of a word or object after just having been introduced to it is linked to the frequency illusion, also called the Baader-Meinhof phenomenon.

**Background**
It may be an example of the **frequency illusion**:

> The illusion in which a word, a name, or other thing that has recently come to one's attention suddenly seems to appear with improbable frequency shortly afterward

It's also referred to as the Baader-Meinhof phenomenon, colloquially described as

> \[T\]he phenomenon where one stumbles upon some obscure piece of information—often an unfamiliar word or name—and soon afterwards encounters the same subject again, often repeatedly.

It's also related to things like buying a brand new car that was just newly released and suddenly it pops up all around the neighborhood.

The Frequency Illusion is thought to be the result of two psychological processes: **selective attention** (noticing things that are salient to us, disregarding the rest) (Yantis, 2008), and **confirmation bias** (looking for evidence that supports a hypothesis and disregarding counterevidence). source: Stanford University

<sub>**Reference**
**-** Yantis, *Curr Dir Psychol Sci* (2008); **17**(2): 86–90</sub>

---
Tags: perception, philosophy-of-mind
---


# Question
Title: Is the effect related to shutting your eyes when a car is turning well known?
Since I was little I realized that when you close your eyes when being in a car and the car turns in a street to the side, you perceive the car turning more in one direction than it actually does.

Does this effect have a name? Is it an example of some well known effect? If so, what is it and where can I learn more about it?

# Answer
**Short answer**
In general, sensory systems are not well equipped to perform absolute estimations of a stimulus level, especially since they adapt to the ambient level of stimulation, *i.e.*, their baseline is re-set continuously. Nonetheless, the vestibular system is quite well capable of estimating the degrees of rotation, as shown in blindfolded subjects that were rotated along the vertical axis.

**Background**
Rotation initiated by an object you are sitting or standing on is sensed by the **visual system** and the **vestibular system**. The visual system is the most accurate, as it immediately senses a change in the visual scene. When the eyes are closed, only the vestibular organ is functional.

Movement in the horizontal plane is sensed by the **semicircular canals** in the inner ear (Fig. 1). One fundamental principle in sensory organs in general is that they operate on a relative scale. In other words, sensory systems excel in *comparing* two stimulus intensities. They are, however, poorly equipped to provide an *absolute measure* of stimulus intensity. How bright is bright? Only through experience does one know the absolute value of a stimulus. I'm in the hearing sciences, and I can pretty well tell what the absolute stimulus level is of a stimulus between 20 and 70 dB. But that's only because I spent hours and hours providing well-defined stimuli to study subjects. If you ask me how bright a certain flash of light is, I surely can't tell you.

What's more - sensory systems adapt quickly (Webster, 2012). For example, if you keep on moving in circles then the sensory end organs in the semicircular organs (hair cells and associated vestibular nerve) adapt and become less responsive to the ongoing stimulus (St. george *et al*., 2011). However, short circular movements in a car are typically short accelerations and decelerations, which are pretty well encoded by the vestibular system. Indeed, blindfolded subjects do pretty well in regaining their original position when rotated about a head-centered vertical axis. It is not until adaptation comes into play that things start to deteriorate. (St. george *et al*., 2011).

**Reference**
**-** St. george *et al*., *J Physiol* (2011); **589**(4): 843–53
**-** Webster, *F1000 Biol Rep* (2012); **4**: 21

Fig. 1. Inner ear. source: MedScape
> 4 votes

---
Tags: neuroscience, perception
---


# Question
Title: Why does Asperger's Syndrome seem to overlap with high IQ?
A few of my friends have Asperger's Syndrome, and some fit the pattern but have not been formally diagnosed. Many of these friends are also highly intelligent, and because of the high intelligence and odd social behavior were stereotyped in school as being "odd geniuses".

In my anecdotal experience, there seems to be a lot of correlation between people with Asperger's and people with high IQ. I'm curious if this is just correlation, or if there is some causation here.

Are some traits of Asperger's actually traits of high intelligence, or perhaps the other way around?

# Answer
**Short answer**: Some traits of Asperger's are found in those with high intelligence, and vice versa. In the grander scheme of things, however, it appears that correlation does not imply causation.

**Longer answer**:

> AS was first described in 1944 by Austrian physician Hans Asperger. He considered it to be a personality disorder characterized by pedantic speech content, impairment of two-way interactions, excellent logical abstract thinking, isolated areas of interest, repetitive and stereotyped play, and ignorance of environmental demands. AS individuals were thought to be capable of originality and creativity in selective fields (Tsai, 1992). Asperger (1979) suggested that his syndrome was more likely to be observed in children of high intelligence and special abilities. However, to date, the clinical literature on AS has focused on children with average or low-average intelligence. There has been surprisingly little examination of AS among gifted children (Barber, 1996; Cash, 1999a; 1999b).

There seem to be at least seven characteristics that are common to both gifted children and children with Aspberger's syndrome. Those are: verbal fluency, a fascination for letters or numbers and/or memorizing information, an intensive interest in a specialized topic, hypersensitivity to sensory stimuli, a large range of abilities due to their specialized interest(s), and uneven social or affective development.

Due to this overlap (and not necessarily in spite of it), Asperger's syndrome is often mistaken for giftedness in children.

There are differences between gifted children without AS and non-gifted children with AS. Unlike gifted children, children with AS often demonstrate motor clumsiness, low tolerance for change or agitation, inability to understand social humor and proper affect, and appear to lack a "theory of mind" (in other words, they may act abnormally and not have any clue that others perceive them to be abnormal).

> Perhaps the most pronounced feature to distinguish a gifted AS student is his or her remarkable lack of insight and awareness regarding the feelings, needs, and interests of other people. An AS child will talk interminably in a monotonous or pedantic tone about a favorite topic, unaware that the listener might not be interested, needs to leave, is bored, or wants to say something. AS children will also interrupt private conversations and enter or leave abruptly without concern for the wishes or needs of others. They seem oblivious to the simplest rules of social conduct, and repeated efforts to instruct them or remind them do not change these behaviors. A pronounced lack of social awareness is not a common characteristic of ordinary gifted children.

Based on this, it does not seem that AS foreshadows high IQ. It seems likely that AS is often misdiagnosed as giftedness/high intelligence, or vice versa, considering the overlap in external behaviors among both groups. In addition, if 100% of your mental energy was spent on one or two very specific interests, and if you set about in such a way that you /only/ talked about those interests whenever possible, you would indeed seem very intelligent and competent. :)
> 10 votes

# Answer
I think that it is a definitional issue.

Here is the first definition of Asperger's I got with a Google search:

"a developmental disorder related to autism and characterized by higher than average intellectual ability coupled with impaired social skills and restrictive, repetitive patterns of interest and activities."

I think that this is very close to the definition Asperger himself used to try to understand the cluster of individuals with similar traits that fit that description (although I don't think he made the connection to autism that we now have).

So, to say that people who are "characterized with higher than average intellectual ability" have high IQ's is pretty much a tautology, isn't it?
> 0 votes

---
Tags: iq, aspergers
---


# Question
Title: How is the g-factor of intelligence calculated?
I am currently reading Dr. Richard Haier's book *The Neuroscience of Intelligence* and I am a little confused about the g-factor. Note that I have no education in psychology outside of general ed courses at university.

I have two questions regarding the g-factor. What confuses me is for one, he does not go into technical detail about how the g-factor is calculated.

He does include this illustration:

Here we see that 15 mental tests are taken in groups of 3, where each group is correlated to a certain factor. So tests 1-3 are for reasoning, 4-6 for spatial ability, and so on. These factors then correlate to the g-factor.

I am wondering what is the methodology used to find the correlations between the tests and factors/factors and the g-factor? For example, I don't quite understand how they measure the correlation between the test and the factor given that the factor is abstract (ie. reasoning). I hope what I am asking makes sense. I am not asking how to perform linear regression or calculate Pearson's r.

My second question is about the statement in the book:

*"Different mental abilities are not independent. They are all related to each other and the correlations among mental tests are always positive.... It strongly implies that all the factors derived from individual tests have something in common, and this common factor is called the general factor of intelligence."*

Wouldn't this imply that all of the factors are multicollinear and make it difficult to distinguish which factors are most significant?

# Answer
**PCA or EFA**: A standard approach to calculating a g factor would be to use principal components analysis (PCA) or exploratory factor analysis (EFA). Basically, you administer a broad battery of cognitive ability measures. Then you use these tests as variables in a PCA or EFA. This will partition the variance in the tests into a set of uncorrelated factors. The first factor will be the factor that explains the most variance in the tests. It is this first factor that represents "g". Typically, each test will "load" (or correlate) with this first factor, some tests more than others. The first factor will capture something that is common across most or all of the tests. I.e., it is g, for general factor, that measures cognitive ability.

An empirical finding is that almost all tests of specific cognitive abilities correlate with the general factor. And typically, the loadings are fairly substantial. I.e., the first factor is quite substantial relative to second and subsequent factors.

**Confirmatory factor analysis**: It seems that what you present is a confirmatory factor analysis. This is a variant on exploratory factor analysis. Basically, you specify which observed variables load on latent factors and all other possible loadings are constrained to zero. More specifically, this is a higher-order confirmatory factor analysis (CFA). It is higher-order because, there are two-levels of latent factors. I.e., tests load on domain-specific latent factors (e.g., reasoning, spatial ability), and these domain specific latent factors load on g.

The CFA estimation procedures will find the parameter estimates that best model the data (i.e., the covariance/correlation structure of the tests).

So in this case, we see that all the tests load fairly well on their domains (i.e., \> .70) and all the domains load on g (\> .65), although reasoning and spatial ability load a little stronger.

In general, multivariate statistics training in psychology (typically presented at postgraduate level and sometimes latter undergraduate-level) will cover these statistical techniques. Here's Bill Revelle's notes that cover some psyhometric theory: http://www.personality-project.org/r/book/

**Wouldn't this imply that all of the factors are multicollinear and make it difficult to distinguish which factors are most significant?** That's why researchers often focus more on g (i.e., the general factor). But yes, you are in a sense correct. Of course, you can still do multiple regression and such with correlated predictors; you can then look at things like semi-partial correlations to look at the unique prediction of any one domain.
> 7 votes

---
Tags: neuroscience, intelligence, correlation
---


# Question
Title: What does it mean statistically for there to be significant differences in average IQ scores between racial groups?
Charles Murray (in his book, "The Bell Curve") reported that there are real differences between the mean IQ scores of different racial groups. He also points out that IQ variation within said groups is greater than the variation between the groups. I'm struggling to reconcile these two statements.

If by "real differences", he means statistically significant differences between group averages--doesn't that entail the variation is greater between groups than within them?

That is, isn't the statistical test for inter-group mean differences (e.g. ANOVA) based on a comparison of the variances within vs between groups?--(if the inter-group variance is comparatively large enough, this constitutes a statistically significant difference between the groups?) If not, then what does it mean to say that the groups are significantly different from eachother?

# Answer
Statistical significance in this context is determined by:

* the underlying size of the group differences,
* the group sample sizes, and
* your threshold for statistical significance (traditionally .05).

Even if there were very small group differences, if you had a large sample size (say 1000s of people from each race doing an intelligence test), then you would be highly likely (i.e., high statistical power) to find a significant group difference.

However, Murray's point is not about statistical significance. I.e., it's not about ruling out the null hypothesis. Observed differences in intelligence test scores are often fairly large, and this is a heavily studied area with very large sample sizes. So ruling our the null-hypothesis is not a problem. The differences in a given study are statistically signifiant.

Murray's point is about translating the quantitative differences in group means into something that is linguistically meaningful. There are various ways of doing this. For variables that are intrinsically meaningful, we often talk about the raw scales (e.g., you could talk about the gender pay gap in dollars earned per year or you could compare races in height using centimetres or inches). However, in psychology, we often have scales that lack intrinsic meaning, which leads to the use of standardized measures of effect.

The most common standardized measure of group differences is often labeled Cohen's d. I.e., it is the difference between group means in terms of the standard deviation. So for example, IQ scores have a standard deviation of 15. So if one group has a mean of 110 and another has a mean of 95, then that's a cohen's d of 1.0 (i.e., (110 - 95) / 15 = 1.0). Rules of thumb have been proposed based on an examination of the psychological literature which suggests that .2 is small, .5 is medium, and .8 is large in terms of an effect.

From memory, some observed differences in intelligence test scores between races are in that 0.8 to 1.2 range (see for example IQ knowns and unknowns). So by conventional rules of thumb for effect size, this would be labelled a large effect or a large group difference.

However, this is not a finding of mere academic interest. This finding can have profound negative consequences for people's lives. Specifically, the fear is that this finding will reinforce negative stereotypes and that people in the group that tends to scores lower on IQ tests will be given fewer opportunities in life (e.g., education, work, immigration, political policy, etc.). And that the finding would support bigotry.

In particular, there is a real danger that people will rely on a group stereotype rather than judging a person on their merits. For example, it is reasonable to hire a person for a job because they show the most aptitude for the job based on measures of the competence and experience. It is unreasonable to hire a person because they come from a racial group that happens to on average perform better on the job.

Murray uses an alternative index of effect size to say that between group variance is less than within-group variance. Thus, if you do a regression with group as the predictor variable, then only when you explain more than 50% of variance will group explain more variance than there is variance within groups. I think you need a cohen's d of 2.0 to get 50% of variance explained.

Here's a simulation in R:

```
x <- data.frame(group = "a", dv = rnorm(100000,0,1))
y <- data.frame(group = "b", dv = rnorm(100000,2,1))
df <- rbind(x, y)
fit <- lm(dv ~ group, df)
summary(fit)

```

Basically, I'm simulating data for two groups and their group means differ by two standard deviations and the result is 50% of variance explained (and 50% variance unexplained; i.e., within group variance):

```
Coefficients:
              Estimate Std. Error t value Pr(>|t|)
(Intercept) -0.0007719  0.0031664  -0.244    0.807
groupb       1.9974176  0.0044780 446.050   <2e-16 ***
Multiple R-squared:  0.4987,    Adjusted R-squared:  0.4987

```

In general, a group difference of 2.0 is very large. Here's another article that talks about different indexes for group differences (Table 1 is particularly interesting).

So, in general, Murray is presumably making the point that even though group differences are fairly large by conventional standards, there are many people in the lower scoring group that score higher than the higher scoring group. So please don't use this finding to stereotype or marginalize people.

### Follow-up

You asked in the comments:

> Given the group differences, is it technically accurate to say that a randomly selected individual of a lower scoring group is more likely to have a lower score than a randomly selected individual of a higher scoring group?

Yes, that is accurate.

To answer that question see Table 1 here.

"Probability that person from experimental group will be higher than person from control, if both chosen at random (=CLES)"

* no group differences: 50% chance
* 0.5 SD difference: 64% chance
* 1 SD difference (i.e., what has sometimes been found historically for some race IQ differences): 76% chance
* 2 SD difference: 92% chance
> 3 votes

---
Tags: measurement, intelligence, statistics, iq, cognition
---


# Question
Title: What is the Golden Standard of Testing Fluid Intelligence?
Not much to add to the title- what is the currently accepted "best" test of fluid intelligence? How was it determined to be the best?

# Answer
> 4 votes
You'll find an answer here:

https://en.wikipedia.org/wiki/Fluid\_and\_crystallized\_intelligence#Measurement\_of\_fluid\_intelligence

As it mentions, Raven's Progressive Matrix is a popular option that has been shown to load highly on both g and Gf (fluid intelligence).

In terms of gold standard, it is probably preferable to have a battery of measures that are relevant to Gf and take some composite of these. For example, the WAIS performance subscales.

In general, a good measure of fluid intelligence would be inferred from its correlations with other measures. It should also have good reliability and other validity properties. Specifically, when administered in a large battery of cognitive ability measures, a factor analysis should indicate that the test loads highly on a factor that looks like fluid intelligence (i.e., that other measures of fluid intelligence load on). There's more to it than that, but perhaps a starting point.

---
Tags: intelligence, test
---


# Question
Title: 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:

# Answer
> 5 votes
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

# Answer
> 1 votes
When from what I've viewed first hand through my formal study working with NANOG, SOX2, & OCT4 Trinity Factor mediation of a Non Canonical Wnt pathway in lineage regression morphology of simple columnar enterocyte to migratory Mesenchymal pluripotent transitory state, has shown me how incredibly novice & crude each our methods, modes of understanding are, as well as the utter bred naivety amounting in those who truncate "truths" of an already ineptly defined material in the first place.

Greater science forever uproots the lies within our yet "greatest" truths, & does so as an auraborus inevitability.

 Brinker, T., Stopa, E., Morrison, J., & Klinge, P. (2014). \[A new look at cerebrospinal fluid circulation.\]\[1\] Fluids and Barriers of the CNS, 11(1), 10.

# Answer
> -1 votes
Would like to disagree with anongoodnurse's answer when it states that *"there are no indications of a CSF fluid pump"*.

CSF fluid is affected by cardiovascular pulse wave in the rhythmic brain motion during the systolic expansion. But the respiratory rhythm plays the most significant role in the CSF movement and was shown to be diminished in flexor dominant individuals (respiratory muscle memory abnormal contraction-sympathetic tone). Couple this with occlusion of the central canal associated with subluxation of the vertebrae, diminished Vasomotor waves (THM) associated with autonomic nervous system weakness, and you get CSF stasis, which lead to abnormal degenerative disease.

The clinical assessment of CSF stasis is associated with vertebral subluxation and can be corrected thru chiropractic adjustments, lymphatic drainage techniques, 12 seconds breathing technique and yoga.

 Whedon, J. M., & Glassey, D. (2009). Cerebrospinal fluid stasis and its clinical significance. Alternative therapies in health and medicine, 15(3), 54.

---
Tags: physiology, neuroanatomy
---


# Question
Title: What does it mean for someone to "join narratives to explain their experiences"?
Describing the Blue Whale Challenge, an online phenomenon where participants perform tasks with the final task being suicide, we have the following:

> Dr Achal Bhagat, a psychiatrist in Delhi, told the BBC he had not encountered a single Blue Whale case, although he speaks to young people every day.
>
> "**People join narratives to explain their experiences**," said Dr Bhagat, adding that is possibly why some children have said they participated in the rumoured challenge despite there being no proof of its existence.
> Aparna Alluri, *Why is 'Blue Whale' hysteria gripping India?*, BBC News, Delhi, 2017

I don't understand what "people join narratives to explain their experiences" means, and how its relevant to the context. It seems to imply that people are making up they've participated in a Blue Whale Challenge (i.e., they join the narrative) because of some (unstated) events in their lives. The quote also indicates it holds more generally, i.e., it's not only true for the Blue Whale Challenge.

**Question**: What does it mean for someone to "join narratives to explain their experiences"?

# Answer
I think there is *nothing formal* psychiatry or psychology related about the psychiatrist's use of language when saying 'people join narratives to explain their experiences'. What he is saying is that people tend to link causally various narratives/stories they have heard of to generate an explanation without much evidence of there being an actual causal link. The joined up narratives then make an appealing sense of things having been explained.

The reason why explanations are appealing is clear upon reading https://en.wikipedia.org/wiki/Blue\_Whale\_(game) \- there is a very disturbing event - suicide by young people, then there is something of an explanation which seems to make some sense.

### See also:

*Causal relatedness and importance of story events*; Tom Trabasso, Linda L Sperry Journal of Memory and Language: Volume 24, Issue 5, October 1985, Pages 595-611 https://doi.org/10.1016/0749-596X(85)90048-8
> 2 votes

# Answer
I think it sits somewhere in between scapegoating (assigning the blame to another person or less often some other force) and "everything happens for a reason". It's a basic psychological need to find causality, especially for upsetting things in life. There is in fact no shortage of attribution theories in psychology, and covariation (same causes leading to same effects) sits fairly highly among them. So if one heard that X commited suicide because of the Blue Whale, and then Y commits suicide and someone else mentions Blue Whale... However, in this case it's probably more appropriate to quote another media article on the Blue Whale moral panic:

> French anthropologist René Girard famously studied how moral panics ultimately derive in scapegoating. Whenever a society goes through difficult times, there is the tendency to unfairly blame an individual or a particular group for all the troubles. The collective animosity builds against these scapegoats, and very frequently, they are either killed or exiled, as an attempt to put an end to the crisis. This is the psychological mechanism at work in lynchings and purges.
>
> \[...\] The Blue Whale designers, whoever they may be, are scapegoats.
>
> The Blue Whale moral panic is far from being the first in its kind. The idea that some media product (a song, a movie or a videogame) has the power to drive mindless kids to kill themselves is quite ancient. The first version of this cultural trope goes back all the way to the 14th Century, with the famous Piper of Hamelin story. According to this legend, a piper was hired to rid a town of its rats; the piper played a melody that drove the rats away; the townspeople refused to pay, and as revenge, the piper played a melody that made the kids mindlessly walk into a river, thus being drowned. The Piper of Hamelin story is clearly fantasy, well suited for the credulous medieval mentality. The Blue Whale story seems to be along the same lines, and unfortunately, the same credulous and paranoid mentality is at work.
>
> \[...\]
>
> Listening to a song or playing an internet game will not make anybody commit suicide, unless that person already had previously strong suicidal ideation. In that case, alleged instigators such as Blue Whale or Judas Priest would be scapegoats.
> 1 votes

---
Tags: social-psychology
---


# Question
Title: Do major historic events have a lasting impact on humankind's objective happiness?
In his book "Sapiens - a Brief History of Humankind", Harari argues that the biochemistry of "happiness" in any person can only move within bounds, dictated by genetics.

He also argues that happiness only improves momentarily when objective circumstances improve, and only e.g. a degenerative disease or permanent physical pain can result in lasting change. This seems to be widely accepted and is backed by numerous studies.

I could not, however, find any studies supporting his statement that events such as the agricultural revolution had no lasting impact on humankind's objective happiness.

**Are there any scientific studies on the biochemistry of happiness of generations that lived before and after major historic events like the cure of a disease that affected large parts of the studied community?**

Whats psychology's take on human happiness throughout history?

Please suggest edits, as I am no expert on any of this.

# Answer
> 3 votes
Depends what you mean by "objective happiness". If we use the term in the way that it's used by Kahneman etc., meaning that

> In the special conditions of the clinic or laboratory it is sometimes possible to obtain continuous or almost continuous reports of experienced utility from patients or experimental subjects. Continuous measures are of course impractical for the measurement of objective happiness over a period of time. Sampling techniques must be used to obtain a set of values of moment-utility that adequately represents the intended population of individuals, times and occasions. For example, a study of the objective happiness of Californians should use a sample of observations that reflects the relative amounts of time spent on the freeway and in hot tubs. Techniques for sampling times and occasions have been developed in the context of Experience Sampling Methodology (ESM) (Csikszentmihalyi, 1990; Stone, Shiffman and DeVries, 1999).

It's hard to imagine getting such data retrospectively from ancient or even just past populations.

Ref quoted: Kahneman, D. (2000). Experienced utility and objective happiness: A moment-based approach. In D. Kahneman & A. Tversky (Eds.), Choices, values and frames (pp. 673-692). New York: Cambridge. University Press and the Russell Sage Foundation.

Generally, diet and/or physical trauma leave a bone recod for archeologists to study. Alas I'm not aware of neurochemistry of past populations being ammenable to study (other than comparative studies across current species, e.g. humans vs apes).

---
Tags: neuroscience, emotion, happiness
---


# Question
Title: Importing EGI eeg binary format data into R?
Are there R packages/functions for importing EGI eeg data format into R?

# Answer
While the available R packages for EEG do not seem to support the EGI eeg data format (see Robin Kramer's comment), you might want to try MNE-Python as a free and open alternative to any EEG toolbox implemented in Matlab.

MNE-Python does support the EGI eeg data format among many others. Furthermore, there are several comprehensive examples to get you started.
> 3 votes

---
Tags: cognitive-neuroscience, eeg, analysis
---


# Question
Title: When is Mindfulness Based Cognitive Therapy not useful, or bad?
I'm writing my Bachelor on MBCT, and while there are a ton of studies on the positive effects of mindfulness and MBCT, I'm wondering if there are any cases where MBCT shouldn't be applied. I've found some litterature on certain possible negative effects of mediation, but nothing on MBCT specifically.

So, do anyone know of studies or research papers that mentions cases where MBCT is not useful or should be avoided?

# Answer
The mindfulness stress buffering account (Creswell, Lindsay, 2014) suggests that mindfulness practice buffers acute stress reactivity, therefore it has more impact on health outcome of a high-stress group than a low-stress group.

Creswell, J. D., & Lindsay, E. K. (2014). How Does Mindfulness Training Affect Health? A Mindfulness Stress Buffering Account. Current Directions in Psychological Science, 23(6), 401–407. https://doi.org/10.1177/0963721414547415
> 2 votes

---
Tags: emotion, metacognition, meditation
---


# Question
Title: Experiment where groups of dogs were treated differently to find difference in affection
I cannot remember where I read this, possibly Eliezer Yudkowsky's HPMOR. I'm looking to read the actual experiment and its results.

The experiment supposedly got 3 groups of dogs. One they consistently treated with only love. The second one was treated consistently negatively. The third group was treated positively and negatively at random.

Supposedly the 3rd group showed the highest degree of affection towards their handlers.

Can anyone point me to the experiment, or any source or detailed description about it?

# Answer
> 2 votes
VSauce mentions this experiment in "Why Do We Kiss?" at 9m 24s in.

<sub> Topál, J., Miklósi, Á., Csányi, V., & Dóka, A. (1998). Attachment behavior in dogs (Canis familiaris): a new application of Ainsworth's (1969) Strange Situation Test. Journal of comparative psychology, 112(3), 219. </sub>

---
Tags: reference-request, attitudes, attraction
---


# Question
Title: What would the effect on psychology experiments be if we found out that one person sees blue if another sees red?
Suppose we conducted an experiment that found that the color red makes people depressed and the color blue makes people happy.

Now suppose we found out that when looking at a red object, person A sees red but person B perceives blue.

Would the conclusions of the experiment still apply?

My take would be that the results would still apply, just that they apply to different definitions and it would be just a matter of semantics.

# Answer
While the sensation of color is well defined, the **perception of color** is indeed shrouded in ambiguity (Brainard, 2001). There are no colors, just electromagnetic radiations that oscillate in different frequencies in the frequency domain. Our brains interpret those various wavelengths as color.

Now on to your experiment: if you find a statistical difference and you later find out that a group of people perceive the color blue as red and *vice versa*, the first thing you want to do is control for that population and take them out from the data set. Then you can compare the 'true seers' with the 'reversed seers' and see if they are statistically different in their emotional response. If yes, you'd better split them and analyze them separately. If not, a pooled analysis is fine, perhaps you can add the normal or inverse perception as a co-factor, dependent on the exact analysis.

But then, perhaps, the most important question here is - *how* would you find out what a person *actually perceives*?

<sub>**Reference**
**-** Brainard, Int. Encyclopedia Social & Behavioral Sciences, Smelser & Baltes (eds.), Pergamon Press, Amsterdam</sub>
> 2 votes

---
Tags: experiment-design
---


title: How much pleasure can brain endure?

text:
# Question
Title: How much pleasure can brain endure?
As of 2018, is it possible to induce pleasure in humans by some intervention like sending electrical signals? I've read that it's been done on mice. If not, it's quite imaginable that it will become possible in the near future. What would be the neurological implications of such intervention, other than addiction? I mean what would happen to the brain if we force the brain to stay in an orgasm-like or ecstasy state for several minutes? What are the possible adverse effects or damages? Of course that we know very little yet, but I appreciate to get some insights on how pleasure works, and if there really are pleasure centers in the brain that can be easily manipulated.

# Answer
> 5 votes
> As of 2018, is it possible to induce pleasure in humans by some intervention like sending electrical signals?

Yes, it is possible and has been done, typically as DBS (Deep Brain Stimulation) for various disorders: OCD and depression are a few examples where the brain are stimulated induced pleasure. (Synofzik, Schlaepfer & Fins 2012)

Regarding "How much"... How much until what? Death? Brain damage? Subjective "that's enough"? Habituation? Realize that most of what you ask is definitely unethical as an experiment (on humans, which is your focus) in this century.

For an ethics discussion I stronly suggest the aforementiond paper paper by Synofzik, Schlaepfer & Fins "How Happy Is Too Happy? Euphoria, Neuroethics, and Deep Brain Stimulation of the Nucleus Accumbens" which has been the subject of interest for popsci press (e.g. article in *The Atlantic*).

A few points paraphrased from the paper:

* the euphoria was a result of deep brain stimulation (DBS) treatment for OCD (obsessive-compulsive disorder) performed in the anterior limb of the internal capsule and the nucleus accumbens region (ALIC-NA).
* The pleasure experienced is voltage dependant. However, patients also reported being overstimulated when the voltage was too high and expressed that as some kind of discomfort either somewhat physical "that's too much", or more psychological concern such as that they felt "unrealistically good”.
* Habituation to the pleasure elicited by this type of DBS reportedly does occur, and pretty quickly, on the order of minutes. This is somewhat surprising given that they also mention the classic experiment of Olds (1958), in which mice kept engaging thousands of times in behavior that rewarded them with brief shocks to the brain's "pleasure center". I'm guessing there's something either in the biology or in the protocol that causes faster habituation in humans, but the paper is not clear on what that is.

# Answer
> 4 votes
Luckily there are not one but several brain areas that when stimulated call for repeat stimulation. That is a way how one can define **pleasure**, by the way. If stimulation of an area makes animal to want more it is pleasurable. If not - the animal will avoid the mechanism that triggers the stimulus - that defines an aversive stimulus.

In the 7 affective system model (where the areas in mammalian brain have been identified) the systems producing wanting repeat stimulation would be SEEKING, PLAY, LUST, CARE and those of avoidance would be FEAR, RAGE, SEPARATION ANXIETY.

As to what happens to animals whose brain sites are overstimulated - they certainly can die and have died in experiments. Brain is a delicate biological system and overstimulating an area electrically is no better than doing this with street drugs. Brain needs to maintain its own balance in order to enable us to make sense of the world. The first problem would be *'cheating the brain'* in addition to the second problem - damaging the brain physically through effects of drugs or electrodes.

Lastly your query is about 'ease' of manipulation. **Not easy** at all. The said brain areas have been identified in humans (who are another kind of mammals) needing surgery for epilepsy when it is often necessary to map brain areas by *brief* stimulation. Then there are experimental treatments using deep brain stimulation - for Parkinson's disease and rarely treatment resistant depression. They are complex and involved procedures, way more complicated than stimulating an 'ecstasy' centre.

The best way of interacting with the brain remains through it's natural interface - language, visual and other sensory stimuli. IMHO this will stay so for a long time. I hope that one can see a dose of optimism in this state of affairs though ;)

# Some references:

* Burgdorf, Jeffrey, and Jaak Panksepp. ‘The Neurobiology of Positive Emotions’. Neuroscience & Biobehavioral Reviews 30, no. 2 (2006): 173–187.
* J. Panksepp. Affective Neuroscience: The Foundations of Human and Animal Emotions. Oxford University Press, 1998.
* Panksepp, Jaak. ‘Affective Neuroscience of the Emotional BrainMind: Evolutionary Perspectives and Implications for Understanding Depression’. Dialogues in Clinical Neuroscience 12, no. 4 (December 2010): 533–45.
* Berridge, Kent C. ‘Pleasures of the Brain’. Brain and Cognition 52, no. 1 (June 2003): 106–28.
* ‘Psychotherapy Is The Biological Treatment’. Medscape. April 2018. http://www.medscape.com/viewarticle/893720.

---
Tags: neuroscience, brain, reward
---


# Question
Title: Benefits of social eating outside of family units
The benefits of eating dinners with your family are documented in "Correlations between family meals and psychosocial well-being among adolescents" by Eisenberg et al. However, is there evidence that this applies also applies to other family-like communities? For example, are the benefits to coworkers or friends cohabiting eating together on a regular basis?

# Answer
The term I was looking for was "commensal meals". Indeed, the benefits of commensality are seen in:

1. Firefighters, wherein commensality correlated with measures of effectiveness \[1\].
2. The general population of Thailand, wherein commensality correlated with happiness \[2\]. However, from quickly reading the paper, it's unclear whether this applies as strongly for families as it does for unmarried people.
3. Seniors in Japan, wherein commensality is associated with "subjective health, food diversity and food intake frequency" \[3\].

However, I didn't find anything relating specifically to room-mates, which seems like a relevant demographic?

\[1\] "Eating Together at the Firehouse: How Workplace Commensality Relates to the Performance of Firefighters" by Kniffin et al.

\[2\] "Health, Happiness and Eating Together: What Can a Large Thai Cohort Study Tell Us?" by Yiengprugsawan et al.

\[3\] "Eating together is associated with food behaviors and demographic factors of older Japanese people who live alone" by Ishikawa et al.
> 3 votes

---
Tags: social-psychology, reference-request
---


# Question
Title: Importance of colors in learning process?
I am starting a graduating project that is an interactive software for learning programming with an animated interface.

To be more specific, it's a software that should help students learning how to write simple programs in a programming language called **C**. Learning **C** at the beginning has its own benefits, so it's featured at many programming disciplines at universities, at least where I live. But there are some details in its syntax that may be obscure for beginners and lead to many errors and, therefore, it's an obstacle to focus on the 'big picture' of a problem, on the essence of a given solution.

Roughly anyone who is learning programming needs to deal with frustration, but I think that the issues I mentioned make things worse. Additionally, the software that is traditionally used for writing and running code is aesthetically poor (I remember how difficult it was to look to that screen for so long when I was a beginner). The result is that many students have a very negative feeling about programming.

So I decided to create a software that, along with some other features, is friendly on its visual aspect. One of the main features is that it allows to hide obscure elements, making an instruction simpler. Anytime, it's possible to expand that instruction and the obscure elements would change it's color, one by one, while some other elements would be colored and animated to indicate that there's a relationship envolved. That's the basic idea.

Many years ago, in 2005, my Calculus teacher, that used to like to speak about the way we learn things, mentioned a discovery about the importance of color and movement in the learning process. I heard a similar thing on the famous **TED Talk from Ken Robinson**, "Do schools kill creativity?". I never searched about it before, but the impression I have is that all these scientific conclusions broke with some formal and strict way of education.

I need a good article about this importance of visualization, colors and movement for two reasons. First, I think my teacher, that supervises my project, doesn't think all the 'fancy stuff' I proposed really have utility. Maybe, because, for my surprise, he wasn't aware about the discoveries I mentioned. Second, there's a formal procedure to submit the project and I need some reference to endorce it.

I found only books about this subject. Off course, it would be nice to read some of it, but for now I really need an article to start the project.

# Answer
> 4 votes
You asked for

> an article that discusses the latest discoveries about how visualization, specially colors and moving images are important in the process of learning.
> ...
> It would be nice to know about a good book about it, but for now I need to start the project and I need an article in first place.

There is one free open access article by Lindelani Mnguni (2014) which funnily enough has a book reference in the quote I am putting below.

"Chunking" is the name given to a technique used to remember things learnt, and Mnguni's article discusses how visualisation helps with chunking, along with the idea that:

> there are at least four main factors that determine how humans “chunk” information, namely, closure, proximity, similarity and simplicity. The *closure* principle suggests that the mind tends to complete figures even in cases where information is missing. The principle of *proximity* (also referred to as the principle of *contiguity*) suggests that when visual features are placed closer to each other, they are perceived as a unit (Mullet and Sano 1995). According to the *similarity* principle, items that have commonalities such as shape, size, colour, texture and orientation are often grouped as belonging together (Mullet and Sano 1995). Finally, according to the *simplicity* principle, items are grouped together according to symmetry, regularity and smoothness. All these principles reflect the behaviour of the cognitive system towards new visual information that has been perceived. (Mnguni, 2014).

With regard to moving images, Mnguni also points out that:

> McClean et al. (2005) present evidence showing that student retention of content material in biology education is improved when such content is presented via a lecture coupled with the animations and when an animation is used as an individual study activity.

McClean et al. (2005) is also available free.

## References

McClean, P., Johnson, C., Rogers, R., Daniels, L., Reber, J., Slator, B. M., ... & White, A. (2005). Molecular and cellular biology animations: development and impact on student learning. *Cell Biology Education*, 4(2), 169-179.
DOI: 10.1187/cbe.04-07-0047 PMCID: PMC1103718 PMID: 15917875

Mnguni, L. E. (2014). The theoretical cognitive process of visualization for science education. *SpringerPlus*, 3(1), 184
DOI: 10.1186/2193-1801-3-184 PMCID: PMC4000355 PMID: 24790828

Mullet, K., & Sano, D. (1994). *Designing visual interfaces: Communication oriented techniques*. New Jersey: Prentice Hall

# Answer
> 1 votes
Chris' answer is relevant, but possibly digging more into psychology literature than needed for the given question. Note that the articles Chris links to do not state that 'by default' using colors and animations improves learning. Instead, what they indicate is that *they can be put to good use* if you take into account how the mind processes colors, spacing, and animations.

**How to put colors, layout, and animations to good use**, is what a big part of *human factors*, *human-computer interaction*, *design*, and *user experience* courses teach you. These fields (which also have academic publications) have already processed some of the relevant knowledge of psychology for you and have translated it into *implications for design*, typically distilled as *design principles* or *heuristics*.

With your given question in mind, the following set of principles seem relevant:

As to your concrete project, definitely have a look at what Bret Victor has been doing. His main premise is that computing systems should be much more interactive. He applied this specifically to programming in his article, "Learnable Programming". Interactivity (which also seems to be reflected in some of the features you shortly describe) might be much more important than 'just' improving the visual appeal.

<sub> Wickens, C. D., Gordon, S. E., Liu, Y., & Lee, J. (1998). An introduction to human factors engineering. </sub>

---
Tags: perception, learning, reference-request, color, visualization
---


title: How can I take the Token Test?

text:
# Question
Title: How can I take the Token Test?
I want to take the Token Test

Is there some website where I can take the test for free?

Alternatively, is there some simple guide to how the test works so I can re-create it?

# Answer
> 2 votes
There are different varieties of the Token Test (*e.g.*, Moreira (2011)). Several of them using physical tokens are explained pretty well and can likely be me made at home (*e.g.* here). I wasn't able to find free digital versions.

<sub>**Reference**
**-** Moreira, *Rev psiquiatr clín* (2011); **38**(3)</sub>

---
Tags: methodology, test
---


# Question
Title: Bias of finding others guilty of own shortcomings
I haven't been in cognitive sciences for long, but in my work I have noticed a curious pattern: Individuals who overwhelmingly attribute the responsibility of their own actions to external causes, accuse others of behavioral patterns that represent the same patterns that they themselves do not accept to be guilty of.

Or maybe it's the other causal direction; they see others being guilty of certain behavioral patterns and subconsciously start behaving in the same ways.

For example: A patient who sees sexual predators in most men, sometimes in very subtle behavioral traits, accuses her partners of not respecting her decisions, of reversal of guilt, etc. However in the process of the accusation, she is unable to accept her partners' decisions ("He doesn't want to continue the relationship, but he doesn't care that I want to"), is uncompromising (Does not accept to establish a basis of communication) and blames them for her lack of communication ("I should not have to always be able to show you what I don't want, it is your responsibility to know.").

What I am interested in is; is there science on this that confirms my observation, or even a name or field of research for it? If yes, are there explanations on why this paradoxical attribution of responsibility happens?

# Answer
> 1 votes
Your first paragraph, in particular, reminds me of the 'fundamental attribution error':

> ... the fundamental attribution error (FAE), also known as the correspondence bias or attribution effect, is the claim that in contrast to interpretations of their own behavior, people place undue emphasis on internal characteristics of the agent (character or intention), rather than external factors, in explaining other people's behavior.

---
Tags: cognitive-psychology, social-psychology, terminology, bias
---


# Question
Title: How many items in a list can a human create without repetition?
Consider the question "Name as many animals as you can."

An average person could no doubt list off about 20-30 animals without repetition.

This is odd seeing as we have a 7-9 item maximum short term memory.

The theory would suggest that as soon as we got to animal 10 we would start repeating the same animals without realising it. Whereas of this is plainly not what a person does. We sort of know "I've already said that one". Even though we wouldn't be able to repeat the whole list back.

Is there a limit to this kind of memory? How many animals can a human list off until they forget whether or not they have named a certain animal? Is it time based or number based?

It feels like we're marking off different neurons in the brain when we say them. So we don't say them again.

# Answer
Recalling items from short term memory is a very different task from creating a list of all unique items. There are a number of strategies for recalling items from short term memory without repeating, you can remember all the items in the list in a random order and all the items you have recalled or you can remember all the items in a fixed order and where you are in the list. When creating a list of unique items you need to create a rule, remember this rule and the number of items you have recalled. The list itself is in long term memory

For example, if you are name as many numbers as you can without repetition, you could say the positive integers 1, 2, 3, ..., N. Equally valid would be the even positive integers 2, 4, 6, 2N. You could also list the Fibonacci sequence 1, 1, 2, 3, 5, ..., $\frac{\phi^n-(-\frac{1}{\phi})^n}{\sqrt{5}}$ or if you know them the digits of $\pi$ 3, 1, 4, 1, .... In all of these cases there is a limit to how far you can get since you need to remember the number of items you have given.

Numbers are obviously easier to create rules for than animals, but for animals you could do something like ant, bat, cow, dog, eel, fly, ..., zho, anoa, bear, cuis, deer, ..., zobo, addax, bison, camel, dingo, ..., zebra, ... I am not sure how far one can really go with this rule, but it will get you pretty far
> 3 votes

---
Tags: memory, short-term-memory
---


# Question
Title: With psychological projection originating in psychoanalysis, is the concept currently considered valid?
In a recent accepted and highly up voted answer by one of our respected users, psychological projection as a defense mechanism was brought forward as the relevant terminology/explanation of what the OP was looking for.

According to wikipedia, the concept of psychological projection seems to have originated from psychoanalysis. Within research, much of Freud's work is now considered pseudoscience, to the degree that we even had a discussion on whether or not questions on psychoanalysis should be allowed on this site.

* **Since Freud, has the concept of psychological projection carried over into modern science?**
* Does additional evidence obtained by modern science mostly support or oppose this concept?

# Answer
There are several important aspects to your question.

Firstly it would be good to know what you would understand by `modern science`. Psychoanalysis is clearly outside the range of physics, mathematics or computer science. If you look deeper into it - so is an awful lot, if not all, of positivistic psychologies (especially when applied to psychological therapies) that are currently considered a valid field of study at university level.

What psychoanalysis is first and foremost, in my opinion, it is a **clinical discipline**. Psychoanalysis is not something that you can learn from books or Wikipedia; there is not even such a thing as a universally recognised textbook of psychoanalysis. But there are such textbooks in biochemistry, physics and mathematics. Furthermore - writings from various psychoanalytic authors tend to look at similar presentations to a significant extent differently.

Hence the answer to your question is rather complicated. The concept of **projection** is alive and well within the field. It is part of the language of psychoanalysis; language that is being used to describe human experience and as such **it has a clear face validity**. It is a term often also used within psychiatry and in practice of non-psychoanalytic psychologies. On the other hand presence or absence of the phenomenon of projection is equally clearly a subjective decision. Here your expectations of what modern science is are important.

Lastly I would like to mention that **insights from biology and neuroscience do matter**. They are very important and do add to our understanding of human brain and mind. But as for practical aspects of psychological therapies of any kind that I know of they are relevant mostly as a tool for triangulation between biological descriptions and psychological. When I first started in this rather complicated field I had an expectation of the great importance of neuroscience to the practice of psychological therapies. The insights are important, of course, but **not really for the practice** except as far as they change what the therapist thinks of the human condition. At least for now and, sadly, I cannot see it being more than that for the next decades. And please do not get me wrong I firmly believe that psychoanalysis itself would benefit from more research, perhaps especially on the information that is provided by the patients.

One could say then, of course, does this *archaic* practice of psychoanalysis or therapies derived from it matter? Well, it does matter a lot, the moment you or your relative develop serious enough psychological problems to think that life is not worth living or you feel trapped in problems that just seem to hit you again and again. Depending on your predilection you may seek phrmacological help and/or psychological.

In terms of references I could offer several kinds: there are studies about what kind of psychological therapies professionals choose for themselves; there are outcome studies for various psychological therapies. Then there are articles directly on the subject of psychoanalysis as a scientific theory. None could however provide a direct and valid answer to your question.

It seems that your question is sparked by Arnon Weinberg's answer to the question: Is there a term that describes the behaviour of a person which transfers personal problems to other people and tries to solve them there? That question describes a clinically defined problem and Weinberg's answer is clinically valid. I think it may be relevant to direct also to the famous stackoverflow answer that starts with: You can't parse \[X\]HTML with regex.
> 2 votes

---
Tags: psychoanalysis, projection
---


# Question
Title: The interactions between hallucinations and reality in people with schizophrenia
A person with schizophrenia sees a door become open, while in reality it's closed. What would he see when he tries to pass through the door?

1. Bumps into an invisible obstacle.
2. He sees the door become closed just before he tries to pass.
3. He opens the door himself just before passing through it, but his brain meticulously ignores his action or alters his memory so that he thinks the door was already open.

# Answer
**Short answer**
Visual hallucinations in psychotic disorders like schizophrenia are typically not simple transformations of an inanimate lifeless object into another state. They are not a car turning upside down, or a door suddenly opening. Instead, they are often '*de novo*' images or scenes, with religious and frightening content and just beyond grasp.

**Background**
What are **visual hallucinations** in the psychotic spectrum? In general visual hallucinations are

> Visual sensory perceptions in the absence of external stimuli (Ali, 2011).

Visual hallucinations (VHs) in psychosis are often life-sized, detailed, and solid. Important for your question - **They are projected either just beyond the reach of individuals, or further away.** They are often images of people, faces, animals, objects, or events. Common are visions with frightening content (bugs, dogs, snakes, distorted faces), and these are linked to distress. Notably, visions of God, angels, the devil, saints, and fairies are common. Also worthwhile to realize is that they are often aware others do not perceive it (Waters *et al*., 2014). For example, I heard a person anecdotally speak in front of our class (more than a decade ago, how time flies) about themselves featuring horns on their head when they would look in the mirror. These horns made them look like the devil in the mirror, which evoked strong feelings of distress. They did'n tell this explicitly, but I'm sure when they would feel on their heads, they wouldn't feel anything (combined tactile-visual hallucinations are, afaik, extremely rare, if existing at all). Instead, they interpreted their hallucinations as something religious, as something threatening and dangerous to themselves.

To place the other answer into perspective: visual hallucinations occur in 16% to 72% of schizophrenics, at some point in the course of their illness (Goodwin & Rosenthal (1971); Ali, (2016)) and their impact should not be underestimated (Oorschot *et al*., 2010).

<sub>**References**
**-** Ali, *Curr Psych* (2011); **10**(11): 22-9
**-** Goodwill & Rosenthal, *Arch Gen Psychiatry* (1971); **24**(1):76-80
**-** Oorschot *et al*., *Schizophrenia Res* (2010); **117**;(2-3): 307
**-** Waters *et al*., *Schizophr Bull* (2014); **40**(S4): 233–45</sub>
> 4 votes

# Answer
Unfortunately hallucinations of visual type seldom occur with schizophrenia. When visual hallucinations occur in schizophrenia or more frequently (but still uncommon) in other disorders they are rather unlike a simulation of the current world - e.g. a closed door becoming open in the room. In addition patient in a hallucinatory state is very affectively taken by the experience and often is just afraid to move. Further - the only way to know would be to ask the patient as to what happened, but given that this kind of event is very rarely, if at all, happening, there is no answer because - how can you set up an experiment. Therefore this question, interesting though it may be, is just of speculative value.

A good article about the topic is:

M Manford F Andermann, **Complex visual hallucinations**. Clinical and neurobiological insights. Brain, Volume 121, Issue 10, 1 October 1998, Pages 1819–1840
> 4 votes

# Answer
Hallucinations by schizophrenics are not a distortion of what they observe from the information of the world .

They do not see or hear something that someone in the same vicinity observes as an indifference . They see and hear the same as a non schizophrenic does. It is a difference in the mental interpretation of the information in the mind.

I am schizophrenic . There is an irony in what I'm going to say next . I know what I'm talking about.

When I am unwell I can misinterpret information from the senses such as sound , as in the purpose of a conversation .

I hear the same words that everybody else hears however the purpose of these words is not to convey the message of these words in the ordinary sense, but I interpret these words as having a concealed meaning that only the other members of the group understand .

I get paranoid that they are talking about me indirectly. I am not proud of this as it can appear that I have some sort of self-importance or narccissm. The question must arise in your mind is, why do I think I should be of a particular importance in a group ?, and why should they attempt to conceal there view of me ? etc. I cannot help it. I am not in control of it.

There is also a question in the mind of doubt about how you are interpreting the conversation, to some respects you disbelieve what you are thinking, but are overpowered by the belief that the way you are interpreting the purpose of the conversation, is the truth.

I wanted to express this as an attempt to make people who are not experts in this, understand what goes on in a schizophrenics mind when they are unwell.

I would like, also, to express a funny story about my condition that involved me and a doctor.

The doctor asked me whether I had been suffering any delusions lately. To which I replied, 'Not as far as I can tell!'
> 0 votes

---
Tags: perception, vision, schizophrenia, hallucinations, psychosis
---


# Question
Title: What does it mean to "control for differences in factors" when looking at gun ownership and homicide rates?
What does it mean "with control for differences in factors" in the sentence :

"Several studies used cross-sectional analyses to detect a positive relationship between the prevalence of gun ownership at the neighbourhood, county, regional or state level and homicide rates, with control for differences in factors associated with homicide (e.g., urbanization, race/ethnicity, unemployment, poverty, crime, and alcohol use)."

What did they do to those factors when they "control" them ?

The full report can be found here, if that helps for context: https://ajph.aphapublications.org/doi/full/10.2105/AJPH.2013.301409

Does that mean that they took in consideration all those factors (urbanization, race/ethnicity, poverty, etc.) in the method to minimize the impact those factors have in the results of the factor that matters the most to homicide rates in this study, in this case gun ownership? If so, how can it be done? An illustrative example is enough.

# Answer
> 1 votes
There are various ways of controlling for other other factors.

Probably the most common is to include these control variable as additional variables in whatever statistical model you are running.

For example, you could run a multiple regression predicting homicide rate from gun ownership on a set of neighbourhoods.

You could then run another regression model that included all the control variables.

In both models you would get a coefficient for the effect of gun ownership on homicide rate. However, in the one with control variables, it would be statistically adjusted for the effect of these other variables.

There are lots of debates about how best to control for other factors and which factors to include. But that's the general idea.

---
Tags: statistics, criminology
---


# Question
Title: Establishing personality from shape AND color preferences
There are many resources on the web that discuss **correlations between the personality of an individual and their preferred shapes or colors**. To give just one example of each

1. http://listening2leaders.com/shape-quiz-learn-colleagues/
2. https://www.kent.ac.uk/careers/Choosing/colour-personality.htm

My questions here are:

* The second of the two links above is from an academic source. Are there extended experimental, peer-reviewed, studies that establish the validity of such correlations?
* From my own empirical observations I know that such correlations do indeed work though they are not not quite as clear cut as these articles make them out to be. Are there any studies that look at both color and shape preferences at the same time?

---

I have found that one very good use to combine shape + color preferences is to weed out deliberately misleading responses. Take the following example

* We have the shapes - square, circle, triangle and squiggle
* we have the colors - red, yellow, orange, green, blue, white and black

Interpolating between the ideas proposed in the two links I have quoted above a "Triangle" personality is far more likely to be a "Red", "Orange" or "Yellow" personality than say a "Blue" one. This could be used to assign a weighting to user responses in order to reduce the likelihood of invalid conclusions being drawn from deliberately misleading responses to the "my favorite shape" question.

Sounds plausible but once again I would like to know if there is any published research on the subject.

# Answer
The question made me think instantly of the **Kiki/Bouba** effect. This effect is seen when people are to ascribe the name Kiki to point shapes and and Bouba to rounded shapes (Fig. 1); the overwhelming majority calls the star Kiki and the blob Bouba. One hypothesis is that Bouba is associated with the round shape because a more rounded shape is made by our mouths when Bouba is said. The mouth is more angular shaped when we say "Kiki." Additionally, "K" is a harder-sounding letter than "B." Those who use the modern Latin alphabet may also be visually swayed: the written letters "K" and "B" are sharp and rounded, respectively (Scientific American, November 2012).

Follow-up studies on this effect have revealed that people

* Associate between femaleness and round shapes, and maleness and sharp shapes.
* associate adjectives previously judged to be either descriptive of a figuratively 'round' or a 'sharp' personality with names containing either round-or sharp-sounding phonemes, respectively.

The authors conclude that sound symbolic associations extend to existing lexical stimuli, and that form and meaning are non-arbitrarily mapped (Pexman & Sidhu, 2014).

**Reference**
**-** Pexman & Sidhu, *Canadian J Exp Psych* (2014); **68**(4): 253-4

Fig. 1. Kiki and Bouba - which is which? source: Wikipedia
> 3 votes

---
Tags: personality, preferences
---


# Question
Title: Resources for learning how best to learn fine motor skills
I am interested in learning how best to learn a fine motor skill, in this case, playing a musical instrument. Presumably there are more or less effective ways to go about it.

Possible factors that I can think of include:

* Practice schedule. e.g. how often? how long? time of day? how long does it take for the neural changes to occur? does it happen during rest?
* Practice structure. e.g. include breaks? how long between breaks? how long should each break be? how many breaks?
* Practice speed. e.g do something slowly first? how slowly? for how long? when to increase speed?
* Practise focus. Are there things that are worth specifically directing attention to?
* Non practise elements. Are there things that can be done outside of practising that help, e.g. visualisation? other exercises?

I appreciate that this is many questions rolled up into one, but my main point is how do I go about learning how best to learn fine motor skills, ideally outside of a teaching institution. Is there a good book on the subject? What even is the name of this subject?

# Answer
> 3 votes
I think the search term you're looking for is 'skill acquisition', but it's a super broad area. There's relevant stuff in memory, second language acquisition, sports science, and teaching surgeons surgery... it's all over the place.

There's a pretty sizeable literature looking just at music specifically, one review article that hits a few of the points you mentioned is this one: Hallam, S., Rinta, T., Varvarigou, M., Creech, A., Papageorgi, I., Gomes, T., & Lanipekun, J. (2012). The development of practising strategies in young people. Psychology of Music, 40(5), 652-680.

The references (and the people citing it) are probably as useful or maybe more useful than the specific results they present, although those are interesting too!

If you want something more pop-sci and readable with a bit of a human story The Art of Learning by Josh Waitzkin is a nice one. It's a personal story, not a scientific study, but not everything has to be an RCT, gotta generate hypotheses from some life experience first, right?

I think you might find that the main take-homes are pretty common sense... feedback is important, get lots of it and get it as close to real-time as possible, distributed practice schedules are better than cramming, and 'chunking' is super important, so focus on learning sensible \`atoms', automatize them, and then combine them.

I know this answer only really scratches the surface of a huge area but anyway I hope it helps.

---
Tags: learning, motor
---


title: Why does the tempo tend to get faster?

text:
# Question
Title: Why does the tempo tend to get faster?
Suppose you're learning to sing or play an instrument, and you'd start playing some piece of music. If you are not experienced enough, the tempo would be unstable, usually getting faster until the end.

This phenomenon is usual, as in this question on Music SE: https://music.stackexchange.com/questions/32405/why-i-tend-to-play-faster-tempo-without-realizing-it

Many correlates it with adrenaline and throbbing heartbeat, but is there an experiment-backed evidence to explain?

(Originally posted in Skeptics SE, but I think this should be the better place.)

# Answer
Tempo should be an objective parameter in music. The same piece is heard differently at higher tempo than in lower tempo. This is sensible if you accept an Aristotelian perspective of music, whereby music is an attempt to represent something real (could be a person's emotions or natural sounds). The key in your question seems to be "not experienced enough". Such a musician can lose focus of the real, intended character behind the piece (if we follow the same Aristotelian perspective). He is likely to focus on short term aspects such as: Grasping the current melodic pattern or focus on his own ability to perform the piece. Focusing on your grasp of melody will make you tend to play faster since your fascination will come from the melody itself, and not from what it represents, or could represent. If you are interested in pushing your ability to perform, like many beginners are (for good reason), you might still tend towards a faster pace since it is simply more challenging neurologically, and might boost the so called "muscle memory". In any case, altering the tempo is altering the piece, and no skillful music performer is supposed to do that against the composer's wish! My own experience is both from playing and composing, even though I have only been doing the latter for quite some time now.
> 2 votes

---
Tags: perception, physiology, music
---


title: Stroke amelioration

text:
# Question
Title: Stroke amelioration
Excessive sugar, like Pepsi, is considered harmful. However, I am wondering if it could be helpful if taken by a victim of stroke during or immediately after a stroke, or somewhat after a stroke? My heuristic reasoning is partly that the brain likes energy in the form of sugar, and so if animals have evolved a method to ameliorate a loss of blood supply to a part of the brain, then that method probably needs energy, and needs to be provided quickly.

# Answer
> 1 votes
When you have an ischemic stroke, the oxygen-rich blood supply to part of your brain is reduced. With a hemorrhagic stroke, there is bleeding in the brain.

During an ischemic stroke, brain cells die of a lack of oxygen. Nutrient supply is indeed cut off as well, but the most acute threat to neurons is lack of oxygen. Because if their high activity, they need a continuous supply of oxygen. Bathing them in Pepsi cola won't stop them from suffocating. Note that they can switch to other fuel sources than glucose and hence nutrient supply isn't the critical factor.

During a hemorrhagic stroke there is pressure buildup in the brain and subsequent mechanical damage. Also here, pepsi coke won't relieve the damage done.

Last but not least, digesting food takes a lot of time. Oxygen deprivation kills neurons in minutes.

<sub>**Source**
WebMD</sub>

---
Tags: neuroscience, neurophysiology, psychopharmacology, brain, pathology
---