# Question
Title: Is there a specific term for false justifications?
I'm not sure "false justifications" is the right term, but it's the closest I can think of. I'm referring to a situation in which a person has already made up his mind for reasons he won't publicly disclose, then tries to justify using specious excuses that don't hold up under scrutiny.

For example, let's suppose a new manager wants to fire an employee for reasons that would be illegal. Instead, he comes up with a laundry list of legal reasons (tardiness, improper dress, poor attitude, lack of productivity). Taken as a whole and unexamined, the list seems overwhelming and thus the dismissal justifiable. But if given the opportunity, the employee could refute each reason individually (has never actually been late, dresses the same as others in the office, is meeting all quotas and agreements, etc).

Similarly, in political conversations a person's argument may be based on a conclusion driven by passions and beliefs, but not data. Then data is cherrypicked to prove the argument rather than forming an argument based on the data.

I'm looking for ways to describe this sort of pre-determination. Is there a language for this?

# Answer
I think the examples refer to a variety of possible terms.

In cognitive science, there is much interest in cases where justification is triggered unconsciously. The general tendency to justify one's decisions - especially the bad ones - is called self-justification:

> Self-justification describes how, when a person encounters cognitive dissonance, or a situation in which a person's behavior is inconsistent with their beliefs, that person tends to justify the behavior and deny any negative feedback associated with the behavior.

When someone makes a decision they know is bad, and uses rational-sounding excuses to obfuscate this, it is called rationalization:

> In psychology and logic, rationalization or rationalisation (also known as making excuses) is a defense mechanism in which controversial behaviors or feelings are justified and explained in a seemingly rational or logical manner to avoid the true explanation, and are made consciously tolerable – or even admirable and superior – by plausible means.

If scientific-sounding data is added to make a decision seem more objective than it is, then it is called intellectualization:

> Intellectualization is a defense mechanism where reasoning is used to block confrontation with an unconscious conflict and its associated emotional stress where thinking is used to avoid feeling.

Cherry-picking data to support an argument is an example of confirmation bias:

> Confirmation bias, also called myside bias, is the tendency to search for, interpret, prefer, and recall information in a way that confirms one's beliefs or hypotheses while giving disproportionately less attention to information that contradicts it.

A common view in psychology is that most explanations of decisions made are actually "post-hoc rationalization", or "post-rationalization" (see for example self-perception theory).

Sometimes justification is done consciously / intentionally. The term you used, cherry picking, is perfectly valid in this case. Another example is spin.
> 8 votes

# Answer
**Dereistic Thinking**: Failure to take the facts of reality into account, so that thoughts derived mainly from fantasy rather than experience and logical inference."

## Dereism

Mental activity that deviates from the laws of logic and experience and fails to take the facts of reality into consideration. In many schizophrenic states, psychic activity is largely expressed without respect to the realities of life. When a patient firmly believes that, as the Redeemer, he cures all illnesses by simple gesture, his or her thinking is said to ebb out of harmony with facts, that is, dereistic. “The separation of associations from experience naturally facilitates dereistic thinking in its highest degree, which is actually based on the very fact that natural connections are ignored" (Bleuler, E. Textbook of Psychiatry, 1930).
> 4 votes

# Answer
Maybe (from wiki)

1. Loopholes

A loophole is an ambiguity or inadequacy in a system, such as a law or security, which can be used to circumvent or otherwise avoid the intent, implied or explicitly stated, of the system. Loopholes are searched for and used strategically in a variety of circumstances, including taxes, elections, politics, the criminal justice system, or in breaches of security, or a response to one's civil liberties.

Example: In 2005 Wal-Mart planned a store in Calvert County, Maryland. While a law in the county restricted the size of a retail store to 75,000 square feet (7,000 m2), Wal-Mart considered a plan that would dodge this restriction by building two separate smaller stores. Though Wal-Mart later withdrew this controversial plan, the plan highlighted a legal loophole.\[2\]

2. Rationalisation

In psychology and logic, rationalization or rationalisation (also known as making excuses) is a defense mechanism in which controversial behaviors or feelings are justified and explained in a seemingly rational or logical manner to avoid the true explanation, and are made consciously tolerable – or even admirable and superior – by plausible means.\[2\] It is also an informal fallacy of reasoning.\[3\]
> 2 votes

# Answer
*fait accompli*, also *done deal*.

> **fait accompli (plural faits accomplis)**
>
> An accomplished fact, something that has already occurred; a (colloquial American) "*done deal*".
>
> Usage: Often said of something irreversible and/or performed without going through standard procedure.

Does it fit here? I'm also looking up for the same word.
> 0 votes

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Tags: terminology
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# Question
Title: Is there a mental health disorder related to a harmful lack of anxiety and stress?
Ataraxia is the freedom from distress or worry in ancient Greek philosophy. However, emotions play a vital role in motivation and decision making. Many disorders relate to having excessive emotional reactions or inappropriate triggers for them. There are also a few concerning a lack of or dulled emotional responses. While high levels of stress and anxiety are seen as harmful, the same concern is rarely shown for the opposite end of the spectrum.

I have been unable to find any information about disorders related to dulled or absent anxiety or stress reactions. I assume this is due to the lower perceived harm, or conflation with depression disorders, but I find it hard to believe no one has done any work in this area. Clinical apathy is not what I'm looking for, since that seems to be typified by acute lack of response or interest in immediate stimulus or short time spans.

# Answer
> 4 votes
Sociopaths (people with Antisocial Personality Disorder) report lower levels of anxiety and stress than the general population. Psychopathic traits tend to foster resiliency and are protective against anxiety.

I'm a board-certified psychiatrist. There is ample evidence in the literature (and basic psych textbooks) that sociopathy have low levels of harm avoidance, decreased physiological responses to stress, and lower overall reported anxiety and fear. There is evidence supporting this.

In fairness, this association has come into question and there are some newer studies that are reevaluating the association between anxiety and sociopathy. Anecdotally, I have never encountered an ASPD patient with comorbid anxiety. I’m sure they exist: I’ve just never seen it, and suspect that it’s rare.

<sub> Hofmann, S. G., Korte, K. J., & Suvak, M. K. (2009). The upside of being socially anxious: Psychopathic attributes and social anxiety are negatively associated. Journal of social and clinical psychology, 28(6), 714-727.
Dinn, W. M., & Harris, C. L. (2000). Neurocognitive function in antisocial personality disorder. Psychiatry research, 97(2-3), 173-190.
Dolan, M. C., & Rennie, C. E. (2007). Is juvenile psychopathy associated with low anxiety and fear in conduct-disordered male offenders? Journal of anxiety disorders, 21(8), 1028-1038. </sub>

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Tags: emotion, psychiatry, stress, anxiety
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# Question
Title: Is HTM (Hierarchical Temporarl Model) accepted as credible?
I ran across this article Why Neurons Have Thousands of Synapses, a Theory of Sequence Memory in Neocortex, which leads to Wikipedia and HTM.

To my reading, this provides a credible theory of sensory encoding and neocortical processing, along with a mechanism for sequence memory. Seems too good to be true.

Am I being gullible? Is this research regarded as credible? Is it the subject of academic research by others quoting this work?

---

So what I'm really looking to do is to quantify and qualify the extent to which this work has influenced the work of others; the extent to which others have either built upon it or proposed alternatives or ignored it entirely. For example, is there any academic thought leader or highly-respected group that has reviewed this material and written in judgment?

# Answer
> 1 votes
In the abstract of the paper you quote, they say (edited by me a bit to make it more brief:

> First we show that a neuron with several thousand synapses...can recognize hundreds of independent patterns of cellular activity... We then propose a neuron model where patterns detected on proximal dendrites lead to action potentials...and patterns detected on basal and apical dendrites act as predictions... We then present a network model based on neurons with these properties that learns time-based sequences.

Basically, they are showing a bunch of things that are true in some simulations they have run, which are based on some biologically plausible assumptions. There is no reason to doubt their simulations, and Hawkins is a credible person.

The basic assumptions they make are grounded in known and agreed upon concepts in neuroscience: the anatomy of different cell types, for example, the effects of synapses at different places in the cell. The whole synthesis of their work, though, is just a hypothesis, and that's also how they are presenting it. It wouldn't make sense, and Hawkins would not claim, that this is "accepted": it's a proposed idea that they show some properties of *in silico*. Even if some cells in the brain do work this way, it doesn't necessarily mean it is an organizing principle, either. If you're interested, Hawkins' book *On Memory* tells a bit more.

You can add a bit of skepticism if you'd like because these authors work for a company that sells patented machine learning technologies based on their neuroscientific work, but I don't think that's a reason to throw them out entirely, and their academic publications seem sound. I like to use Google Scholar to track citations of a given paper; if you follow that link or find the paper there on your own, you'll see it has been cited ~150 times, though many of those citations are coming from a more computational/machine learning angle, which makes sense: that's the main application for the paper. It's not really proposing any novel biology, since the biology is mostly based on things already known.

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Tags: computational-modeling
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# Question
Title: How could siblings rivalry / jealousy be useful to human evolution?
It looks like a useless burden and a waste of energy, why it evolved?

# Answer
> 1 votes
First, it must be understood that not all traits in an animal are evolved or selected traits – some are only variations. Some of these variations may be selected by some evolutionary pressure in the future and then become evolved or selected traits.

For example, each of the various hair colors (black, brown, blond, red, white, etc.) is not an evolved or selected trait – all of them are only variations in hair colors. For now, there is no evolutionary pressure to select any of them, so present-day people have various hair colors. But suppose there is a strange disease that gradually kills off people who do not have blond hair; then the blond hair will be selected by this evolutionary pressure. And after some time, there will be only people (or the majority of people) with blond hair. At this stage, the blond hair will become a selected trait. These also happened to the variation of the finch’s beaks in Galapagos, some of which were selected by evolutionary pressure in some specific ecological niches. This pressure led to speciation that resulted in various kinds of finches that Darwin found in various niches. So were true for variations in appendages, which at first were in in-complete forms but later were selected by evolutionary pressure in various ecological niches and evolved into arms, wings, and fins.

How do we know that a trait is an evolved/selected trait or a variation of a trait? One important characteristic is that, if it’s an evolved/selected trait, it will appear in all or in the majority of that species. So, for example, the human hand, the bird wing, and the fish gill appear in all humans, birds, and fish – these are evolved/selected traits.

Yet, not all traits that are present in all/the majority of a species always are evolved/selected traits. Some may be just vestigial traits or just results of genetic drifts (see Evolution’s Useless Traits). But these are exceptions rather than the general rules.

The general rules of evolution are variations in traits, competition, differential production/survival among different traits, and heritability of (some) traits (Natural selection, Natural Selection – Wikipedia).

For the case in question, siblings jealousy/rivalry that is strong or destructive does not seem to be an evolved/selected trait because it does not occur in all humans and not in the majority of human families. It’s probably just a variation trait in some families. And minor jealousy/rivalry is not an evolved/selected trait either. It is probably just one emotion of several emotions that the versatile amygdala (and other emotion-creating neural centers) can produce (to flag various kinds of stimuli that an animal encounters). The amygdala is the evolved/selected trait; any of the various emotions (including sibling jealousy/rivalry) that it can produce is not.

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Tags: evolution, evolutionary-psychology
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# Question
Title: Post alcoholic depression and mental health
We all might have experienced a post-alcoholic hangover after heavy drinking. I think this includes a depressive state, which doesn't last long and wears off once we take rest.

My question is whether occasional excess alcohol consumption can make you depressed permanently? Specifically, I'm wondering whether occasional binge-drinking can lead to a permanent depressive state in the brain?

# Answer
There have been several studies that show links between binge drinking and depressive symptoms.

However, it's hard to make any strong statement about a particular level of drinking, because drinking behaviors are so variable, and also to quantify the "level" of the effect on depression, because depression symptoms are also variable.

Finally, it's hard to make causal statements because alcohol use could be a coping mechanism for depressive symptoms rather than causal: many studies approach the relationship from the opposite direction, implying the depressive symptoms are causal for alcohol use.

I've pulled a few papers and can discuss them briefly, though this is not a comprehensive review.

---

*Paljärvi, T., Koskenvuo, M., Poikolainen, K., Kauhanen, J., Sillanmäki, L., & Mäkelä, P. (2009). Binge drinking and depressive symptoms: a 5‐year population‐based cohort study. Addiction, 104(7), 1168-1178.*

> "This study found a positive association between baseline binge drinking and depressive symptoms 5 years later." "Binge drinking was related to symptoms of depression independently of average intake."

I'd note that this study shows some truly massive relationships, odds ratios of 4-9 for some subcategories; it also seems to have some potential for demonstrating a causal role when they are comparing time 1 drinking to time 2 depression, though still not conclusive.

I think this study gets closest to testing what your question is asking, because it explicitly includes measures of hangovers/binging that are missing from some other studies. It also shows a dose-dependent relationship where more frequent binge drinking is associated with more depressive symptoms, but the relationship is still present even at lower levels of binge drinking compared to non-binge drinking.

---

*Grant, B. F., & Harford, T. C. (1995). Comorbidity between DSM-IV alcohol use disorders and major depression: results of a national survey. Drug and alcohol dependence, 39(3), 197-206.*

> "Virtually all odds ratios were significantly greater than 1.0, demonstrating that comorbidity of alcohol use disorders and major depression is pervasive in the general population. The magnitude of the association remained stable across the three time frames but diagnostic and subgroup variations in comorbidity were noted. The association between alcohol dependence and major depression was greater than the association between abuse and major depression and the association between alcohol abuse and major depression was consistently greater for females and blacks, compared to their male and non-black counterparts."

This studied focused on older adults, age 57+.

---

*Hill, K. G., White, H. R., Chung, I. J., Hawkins, J. D., & Catalano, R. F. (2000). Early adult outcomes of adolescent binge drinking: person‐and variable‐centered analyses of binge drinking trajectories. Alcoholism: Clinical and Experimental Research, 24(6), 892-901.*

> "Adolescent alcohol use did not predict educational attain-ment, crime, family roles, or depression."

This study patterned adolescent (\<18yo) drinking behaviors into several categories and showed relationships between alcohol use and several other outcomes, but not depression, at age 21.

---

*Okoro, C. A., Brewer, R. D., Naimi, T. S., Moriarty, D. G., Giles, W. H., & Mokdad, A. H. (2004). Binge drinking and health-related quality of life: do popular perceptions match reality?. American journal of preventive medicine, 26(3), 230-233.*

> "After adjusting for confounding factors, frequent binge drinkers were more likely than non-binge drinkers to experience ≥14 unhealthy days (physical or mental) in the past month (adjusted odds ratio \[AOR\]=1.39, 95% confidence interval \[CI\]=1.24–1.56), primarily because they had more mentally unhealthy days than non-binge drinkers (AOR=1.52, 95% CI=1.32–1.75)."

This study combines depressive symptoms with other categories of mental/physical health to assay general quality of life.

---

And finally I'll end with one meta-analysis:

*Boden, J. M., & Fergusson, D. M. (2011). Alcohol and depression. Addiction, 106(5), 906-914.*

> The current state of the literature suggests a causal linkage between alcohol use disorders and major depression, such that increasing involvement with alcohol increases risk of depression.

They seem to make some arguments for a causal alcohol use -\> depression relationship, though I haven't read closely enough to decide whether I am convinced by those arguments.
> 2 votes

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Tags: depression, alcohol
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title: How to filter noise in EEG data

text:
# Question
Title: How to filter noise in EEG data
I am a computer science student and I'm doing something for a psychology professor.

We have EEG data from an experiment where a person was shown 140 images for 2 seconds each. We placed 64 electrodes on the scalp so we have 64 channels of continuous data.

We want to correlate each node with every other node so that we can graph it using a chord diagram.

Since my professor is abroad, I am having trouble with the directions he gave me to manipulate the data to get the correlations.

> "Once you are able to read the matrix of channels I suggest subtracting the mean signal from each, filtering to remove noise above 30 Hz."

My question is how to remove the noise above 30 Hz? For example, data for 1 electrode for 10 milliseconds looks like this (measured in uV):

```
[ 31172.50, 31173.53, 31174.80, 31177.34, 31173.73,
  31172.85, 31172.75, 31172.70, 31174.95, 31178.95]

```

The python script I am using also gives this data:

```
sampling rate: 1000.0 Hz
time: 0.0 s to 1883.15 s

```

Can anyone point me in the right direction what steps to take to remove noise above 30 Hz? And also, is that a good way to compute the correlations between the electrodes?

# Answer
*Removal of noise* can be done in various ways:

**Conventional filters**: You could create a digital low-pass filter, such as a Chebyshev or Butterworth filter with a cut-off frequency at 30 Hz (*filt* or *filtfilt* function in Matlab).

**FFT-based filtering**: FIR filters remove frequencies in the frequency domain. So first a Fourier transform is done and then the frequencies \>30 Hz can be removed from the signal simply by assigning '0' to the FFT coefficients at \>30 Hz. A reverse FFT then brings your signal back (*fftfilt* in Matlab).

**Wavelet transforms**: Being a relatively complex and processing-power-hungry method, it may not be the method you are after. However, it may be more efficient in removing certain types of noise or to extract certain features from a signal (*cwt* or *dwt* functions in matlab).

I'm not familiar with Python. Finding the corresponding filters in Python should be fairly straightforward. There are more filtering procedures but the above should get you going.

*Correlation analysis* can be done by various methods, including **Pearson product moment correlation**, **Spearman rank order correlation**, **Kendall rank order correlation** and **mutual information**. See Bonita et al., 2014, DOI: 10.1007/s11571-013-9267-8.

*Subtracting the mean signal* from a particular channel basically reduces signal offset (the DC signal), comparable to a high-pass filter with a very low cut-off frequency.
> 4 votes

# Answer
The common steps are: \- Raw Signal (after pre-amplifier and amplification) \- Band pass filter \- Band rejection/Notch filter (cutoff depends on where you're at) \- Anti Aliasing Filter \- Sample/Hold \- MUX(if you have multiple channels) \- ADC \- Digital Signal

like AliceD mentioned you can use FFT based filters and WT as a filter. For WT you basically apply it to the signal(after selecting a mother wavelet) and you will get a number of coeeficients representing different frequency components which can then be subtracted from the raw signal to remove the noises.

Apart from these filters you could also use spatial filters, a very common one is CSP(common spatial patterns) or others like MEC, CCA, AC, CAR, ICA etc.
> 0 votes

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Tags: neuroscience, measurement, eeg, correlation
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# Question
Title: How happy are people relative to neutral (as measured by experience sampling)?
Most studies on experience sampling are about whether some activity correlates with increased or decreased happiness/subjective well-being. However, it's often hard to tell from these studies what number corresponds a neutral point, where someone is neither unhappy or happy (or equally so), or is feeling an valence/affect equivalent to a nonconscious state. For instance *Experience Sampling Method: Measuring the Quality of Everyday Life* (2007) shows its results in terms of z-scores, which are defined relative to some average, but it's unclear whether that average would be higher or lower than a neutral point. As such, while we can say that these people are happier in this situation than another, it's hard to see whether they're overall happy or unhappy in that situation.

I'm not particularly interested in what activities or age or gender correlates with happiness, but just how happy people are relative to some clearly defined neutral point. Ideally, the study wouldn't just show some average among all study participants across all their experiences, but also what percentile corresponds to what happiness ratings, and the range of happiness scores and the frequency of different happiness ratings for each person. Is there a study that addresses this topic?

# Answer
Diener and Diener's "Most People Are Happy" (1996) summarizes the results of various studies on how happy people are, and finds that the vast majority of people are happy, based on a variety of methodologies.

Abstract:

> Myers and Diener (1995) asked “Who is happy?” but examined the question of who is more and who is less happy. In fact, most people report a positive level of subjective well-being (SWB), and say that they are satisfied with domains such as marriage, work, and leisure. People in disadvantaged groups on average report positive well-being, and measurement methods in addition to self-report indicate that most people's affect is primarily pleasant. Cross-national data suggest that there is a positive level of SWB throughout the world, with the possible exception of very poor societies. In 86% of the 43 nations for which nationally representative samples are available the mean SWB response was above neutral. Several hypotheses to explain the positive levels of SWB are discussed.

Here's the section on experience sampling:

> In two other studies (Thomas & Diener, 1990), college students who were "beeped" reported more positive affect than negative affect on about 80% of occasions. Similarly, Williams, Suls, Alliger, Learner, and Choi (1991) found that working mothers who were signaled at random times reported very high levels of positive affect and low levels of negative affect. Larson (1989) used the beeper methodology with American children; they reported predominantly positive affect about 52% of the time, neutral or mixed affect on about 29% of the occasions, and dominant negative affect 19% of the time.
>
> Brandstatter (1991) drew his respondents in Europe from unemployed persons, soldiers, students, married couples, and members of charity organizations. Participants recorded a selfselected word that described their current mood when they were signaled. Joy and relaxation were reported 43% of the time, and sadness, anger, and fear were reported 22% of the time. On average, respondents reported positive emotions 68% of the time.
>
> Diener, Larsen, and Emmons (1984) examined subjects' levels of mood in different situations. The moods ranged from slightly positive, when respondents were alone, to extremely positive, when participants were in social, recreational situations. Finally, Delespaul and deVries (1987) studied chronic mental patients living in the community and found that the average mood at the time these patients were signaled was above the neutral point of the scale.

These results of happiness were considerably higher than what laypeople and psychology professionals expected:

Diener et al. (2018) adds that:

> Biswas-Diener, Vittersø, and Diener (2005) found that among the Inuit (indigenous people of Greenland), the Maasai (the traditional pastoralist-hunter tribe in southern Kenya and northern Tanzania), and the Amish, the vast majority of respondents scored above neutral in both satisfaction and affect balance. The self-report survey results were replicated with several other measures of SWB—informant reports, experience sampling, and a memory measure—reducing the plausibility that the positive responses are due only to self-report biases. In addition, all three groups were above neutral on satisfaction with each of 14 different life domains. Thus, the finding that most people are happy generalized to cultures that differ significantly from mainstream Western culture.

Diener, E., & Diener, C. (1996). Most People Are Happy. *Psychological Science*, 7(3), 181–185. https://doi.org/10.1111/j.1467-9280.1996.tb00354.x

Diener, E., Diener, C., Choi, H., & Oishi, S. (2018). Revisiting “Most People Are Happy”—And Discovering When They Are Not. Perspectives on Psychological Science, 13(2), 166–170. https://doi.org/10.1177/1745691618765111
> 2 votes

# Answer
I just finished reading this article (2018) by Michael Plant, a PhD student at Oxford University. Given that it is not a peer-reviewed paper, it would be worth checking his references, but this is what he says about the neutral point:

> Life satisfaction surveys don’t ask people to specify what point on the 0 to 10 scale they would consider equivalent to not being alive. 0 is labelled not at all’ and 10 ‘completely satisfied’. ... How could we settle where the neutral point is? Two strategies seem possible. First, we could find out at what LS scores individuals report their lives are neutral on experience measures of SWB. Second, we could poll people to ask at what LS score out of 10 they would be indifferent between living with that score for the rest of their life or dying. I am unaware of any analysis which has been conducted along either lines. Thus, for the moment, this unfortunately remains a point of armchair conjecture.

Note: LS = Life Satisfaction; SWB = Subjective Well-Being.
> 4 votes

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

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

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

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

# Answer
> 1 votes
Your question is really broad and can encompass libraries. However, to add my 2-cents worth regarding

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

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

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

> \[the\] specific\[...\] neurological root

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

<sub>**Reference**
**-** Brody & Inoue, Issues Innov Nursing Practice, 218-27</sub>

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Tags: neuroscience, motivation
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title: Imagining unreal stuff

text:
# Question
Title: Imagining unreal stuff
This is probably the most adequate stackexchange for this question.

Is it possible to imagine something that does not exist, explicitly or implicitly, in our universe?

Exclude things such as a Unicorn for example, that's just a horse and the corn is from other animals who have such an "organ". Other stuff might be just an application of the laws of nature. Our images of extraterrestrials usually involve hands, eyes, holes as nose etc.. which we do know of.

# Answer
> 1 votes
The best known examples of impossible objects are one of the following (but there are a multitude of others around).

Of course they exist as you see right in front of you on your screen. Yet, that is in 2D space. If you imagine these objects to be 'real' matter, so imaginary physical objects, and imagine tracing the cube's ribs (Fig. 1) with your finger, or the ribs of the triangle (Fig. 2), or the tripod (Fig. 3) you are imagining the impossible. Such an object cannot exist in 3D space. Likewise, if you imagine tracing the water in the waterfall (fig. 4) falling and flowing back up, against the laws of gravity, you definitely imagine an impossible thing, as such a scenario can only exist in 2D space - our mind tricks us into assembling an impossible 3D perception out of a 2D image.

Escher has made many of these impossible objects that exist only in 2D space.

**Reference**
Escher op reis. Frederico Giudiceandrea

Fig. 1. Impossible cube. source: SLU Math

Fig. 2. Impossible triangle. source: Brain Teaser

Fig. 3. Impossible tripod. source: Piscesdna

Fig. 4. Escher's Waterfall ('Waterval'). source: Hanover College

---
Tags: cognitive-psychology, philosophy-of-mind, imagery
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title: EEG analysis free software?

text:
# Question
Title: EEG analysis free software?
I'm looking for free software for EEG data processing. What free or opensource software packages are available for analyzing raw EEG data?

# Answer
The eegkit package for R is a good and open source toolkit for data analysis. It is easy to use and you can get really cool plots.
> 1 votes

# Answer
There are several options that I found in this ResearchGate question.

The most prominent truly open source options seem to be MNE and PyEEG but I have no hands on experience with either.
> 0 votes

# Answer
The main programs in the field are: Fieldtrip and EEGLAB. These are MATLAB-based but can be run on Octave (opensource implementation of basic MATLAB) which would be a good suggestion if you ever have any intent on working with other people looking at EEG data in research institutions etc.

The only other real alternative is MNE (Python-based), as suggested above. I use both EEGLAB and MNE for different things and I think having the ability to use both is definitely beneficial. If you are more used to the Python way of doing things then this might be your best option, although it's not as beginner-friendly as something like EEGLAB (but might be more intuitive if you've never used MATLAB-style coding before).
> 0 votes

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Tags: eeg, data, software, analysis
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title: What does this writer mean?

text:
# Question
Title: What does this writer mean?
I hope I am asking this question in the right place. In her reading of Duras's *Hiroshima mon amour*, Julia Kristeva, the analyst and philosopher, refers to Duras as a melancholic. Anne Juranville, also an analyst and a professor of literature, however, believes, in Kelly Oliver's words, that "

> Duras is too depressed to be melancholic Oliver, 2001, 152

Can anyone explain what she means by this? Isn't the melancholic, in the last analysis, the same as the depressed?

What does she mean by saying that

> the melancholic “subject,” and in particular the feminine one, maintains an immediate, traumatic relation to the real qua maternal Thing. Ibid

Here's part of the paragraph cited from Kelly Oliver's *Psychoanalysis, Aesthetics, and Politics in the Work of Kristeva* (2009):

> Anne Juranville, also an analyst and professor of literature, disagrees with Kristeva’s clinical diagnosis, arguing that Duras is too depressed to be melancholic, but does agree that the melancholic “subject,” and in particular the feminine one, maintains an immediate, traumatic relation to the real qua maternal Thing. This nostalgic denial of individuation, as for Kristeva, positions the melancholic beyond the pale of symbolic intervention, unable to access in any way the historical reality of the social: “Stupefied, horrified, \[the melancholic\] fixes himself in an inhuman zone beyond death where, lacking the least symbolic recourse, he is condemned to remain eternally and passively concentrated on this gaping wound that he himself is” (1993, 54). ibid

# Answer
> 1 votes
As Bryan indicates, this question is hardly answerable in the context of science. However, I can take a bash at it;

> Can anyone explain what she means by this? Isn't the melancholic, in the last analysis, the same as the depressed?

No, melancholy is more of a 'normal' emotional state, whereas depression is a debilitating mental illness associated with morbid symptoms and higher chances of suicide.

As to that other passage, I reckon that's really a biased, opinion-fueled statement with no relation whatsoever in science. To cite a part of the wiki page on her:

> Her \[...\] work includes \[...\] intertextuality, the semiotic, and abjection, in the fields of linguistics, literary theory and criticism, psychoanalysis, biography and autobiography, political and cultural analysis, art and art history.

These areas of expertise are quite far from science. Psychoanalysis comes closest, but even that is disputed in terms of not being embedded in evidence-based science.

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# Question
Title: task-fMRI to determine TMS site (online stimulation with that same task)?
I am planning an experiment whereby rTMS would be administered to subjects while they perform a language task, with the hopes of improving performance on this task as compared to sham stimulation.

Due to the novel nature of this task, it is difficult to predict the most optimal region which to choose as a stimulation site. Someone in our group suggested to run this task in the scanner, and choose as the stimulation site the main cluster that the task activates, in other words the cluster that comes out of the fMRI contrast relevant for this task.

This however seems to me excessively data-driven, as well as somehow circular (though it would not be correct to quite call it double dipping).

Does this approach make sense at all?

# Answer
This is not a circular question. In fact, using fMRI to create targets is useful to determine TMS targets outside of the motor cortex or visual cortex. See the study here that used fMRI during a task to generate TMS targets, and then applied theta burst stimulation to those targets: https://www.pnas.org/content/113/21/6059

BOLD contrasts are very useful when using TMS to target sites outside of motor cortex, visual cortex and frontal eye field, where TMS can be validated functionally using motor evoked potentials (MEPs), phosphenes or saccadic eye movements, respectively. Brainsight TMS Navigation enables BOLD contrasts (or peak MNI co-ordinates derived from BOLD contrasts) to be entered as targets for TMS.
> 1 votes

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Tags: neuroimaging, fmri, tms
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# Question
Title: Modelling the Human Brain as a directed graph
A mathematician on the MathOverflow, Hans-Peter Stricker, recently(2016) considered the possibility that human brains may be modelled as directed graphs with neurons as nodes and synapses as edges. I think this makes sense as neurons are mostly unidirectional.

Now, what I am curious about is whether there are ever errors in the developmental process such that there are 'collisions' between two neurons. I can imagine this occurring in two ways:

1. Is it possible for dendrites to connect to other dendrites?
2. Alternatively, can axon terminals connect to other axon terminals?

If so, are there publications that estimate the natural frequency of such errors in a human brain?

## References:

1. Edward T. Bullmore and Danielle S. Bassett. Brain Graphs: Graphical Models of the Human Brain Connectome. 2011.
2. Danielle S. Bassett and Edward T. Bullmore. Small-World Brain Networks Revisited. 2017.

# Answer
> 2 votes
Axo-axonic synapses and dendrodendritic synapses exist, and are not errors. They are particularly common in invertebrate nervous systems but are also found between particular cells in mammalian brains. I would say they are relatively understudied but not ignored.

True errors of the type you describe seem extremely unlikely to me. Synapses do not simply impinge on other fibers, there is extensive pre- and post-synaptic machinery, and bidirectional communication is necessary for proper synaptogenesis. Synapses are held together by connective proteins that are anchored in each membrane.

However, in terms of thinking of the brain as a "directed graph" one need not consider these uncommon synapses to have bidirectional connectivity: it is entirely possible, if not common, for cells to make traditional axon-dendrite synapses on another neuron that makes a reciprocal axon-dendrite synapse.

Graph theoretical approaches to understanding the brain are quite common, however, and certainly did not arise on StackExchange in 2016, as your own references make clear. There is no need for a directed graph to only have connections in a single direction, either. Any connectivity matrix can be interpreted in terms of graph theory.

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Haydon, P. G., & Drapeau, P. (1995). From contact to connection: early events during synaptogenesis. Trends in neurosciences, 18(4), 196-201.

Kawaguchi, Y., & Kubota, Y. (1997). GABAergic cell subtypes and their synaptic connections in rat frontal cortex. Cerebral cortex (New York, NY: 1991), 7(6), 476-486.

Pinault, D., Smith, Y., & Deschênes, M. (1997). Dendrodendritic and axoaxonic synapses in the thalamic reticular nucleus of the adult rat. Journal of Neuroscience, 17(9), 3215-3233.

Somogyi, P. (1977). A specific ‘axo-axonal’interneuron in the visual cortex of the rat. Brain Res, 136(2), 345-350.

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Tags: theoretical-neuroscience, brain-development, connectionism
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# Question
Title: What is the difference between hypnosis and meditation?
It seems that many people say that hypnosis and meditation are very similar. But what are their key differences (both in a soft and hard way)?

# Answer
I believe this question is impossible to "answer" because the inherent premises in the question are based on the assumption that there are two discrete dichotomous phenomena, "hypnotism," and "meditation," which can somehow be meaningfully "defined," and, then, "compared."

Both "hypnosis" and "meditation" are figuratively vast conceptual collages of imprecise multiple-meanings, observations of what appear to be "special" states of human awareness, and consciousness, admixtures from what in "western science" is termed "psychology" with an equally vast mix of practices, lumped-together as "spiritual," from the world's religions, etc.

From the viewpoint of epiphenomenal philosophy ... wikipedia entry ..., and from some modern, western, theorists of human consciousness as grounded in our biological, neurological, reality, both hypnosis and meditation can be regarded as secondary phenomena: in the sense that they are culturally defined and shaped modes of thought, behavior, and experience, in a "continuum of consciousness," which, over time, are conserved, institutionalized, even valorised into being perceived as "sacred."

In Vipassana meditation, in the Theravadan Buddhist tradition (Sanskrit "sthaviravada," "teachings of the elders") one way the "anti-goal" of meditation could be defined is: it is a practice meant as a vehicle for the de-hypnosis of the "illusory personal, small, self," leading to a direct experience of the "real, undifferentiated, trans-personal Self."

But, in that tradition, in its "purest" form, meditation is *not* a "goal in itself," and meditation is *not* a "means to an end" of achieving "altered states of consciousness."

But, there are countless other types, schools, philosophies, of "meditation," with very different conceptual underpinnings, some "secular," some "formally religious," and a wide range of behavioral practices associated with them.

On the "grossest" level, you might say we observe, when we see what appears to be hypnosis of one person by another, a loss of conscious, and subconscious, control of self from the person hypnotized to the hypnotist. But, then: there's stage hypnosis, self-hypnosis, so-called therapeutic hypnosis for behavior modification (such as giving up smoking, etc.).

While we typically associate meditation with acts of what we define, in western psychological terms, as individual "self-control," and "discipline," there are traditions in which group practices (rituals) leading to mass ecstasy are considered meditation (Sufi Zhikr ?).

From one perspective, "cultural identity," itself, can be considered a cohesive set of internalized hypnotic states of mind: continually reinforced from within, and without, the self, and modified in biological development throughout the life-cycle ... I am not referring, here, to the movie-series, "The Matrix" :) !

Suggested readings:

1. Hypnotism and psychotherapy: Milton Erickson ... Amazon page ....
2. Psychology and consciousness: books by Robert Ornstein ... Ornstein's website ...; books by Andrew Weill ... Weill's Amazon page ..., books by Steven Pinker, particularly, "The Language Instinct" ... Pinker's website ....
3. Meditation and Buddhism:

a. Donald Lopez ... "The Story of Buddhism: A Concise Guide to Its History & Teachings" ...: excellent overview of how original Buddhism became "modified:" incorporated a mixture of Vedic/Hindu classic ideas (influence of Advaita Vedanta, and Yogacara schools, for example); incorporated Sivaite Tantra as developed in what is now Bengal; and, later, became "deistic," with an elaborate hierarchic pantheon, in India, Tibet, China, Japan (into what can be loosely lumped together under the rubric "Mahayana Buddhism"). Depending on your biases, you might say, rather than "modified:" "evolved," or "corrupted.."

b. Theravadan Buddhist tradition (Sri Lanka, Southeast Asia), and Vipassana meditation (aka "mindfulness", or "insight" meditation): Walpole Rahula ... "What the Buddha Taught: Revised and Expanded Edition" ...; Thich Nhat Hanh ... Amazon page ...; books by Joseph Goldstein ... recommended: "Insight Meditation: The Practice of Freedom" ...; books by Bernard Kornfeld ... Amazon page ....
> 5 votes

# Answer
Main difference is that the meditation is self-induced and with full self-awareness, whereas hypnosis is usually induced by another person (unless is self-hypnosis which is self-induced) and the person is in state of trance, amnesia or unconscious.

Hypnosis is defined by the U.S government as "the bypass of the critical factor of the conscious mind and the establishment of acceptable selective thinking.". Hypnosis can help you in various ways and is a calm state of altered-consciousness that allows a person to recall memories or be guided to change a behavior (in example to help someone stop smoking).

While meditation is a practice in which an individual trains the mind or induces a mode of consciousness. An ordinary person may be consider meditation as a prayer or total stillness, but the goal of meditation is to focus and quiet your mind, eventually reaching a higher level of awareness and inner calm.

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According to some beliefs or movements, the meditation from ancient times is the method of communication with other realms/planes of existence (Sephiroth) and entities (higher self, astral beings, dead relatives, demons, aliens, ascended masters, angels, God, etc.), astral travel, remote viewing, clairvoyance or altering your body (Reiki, activating chakras, 3rd eye or DNA activation) or time-space reality (psychokinesis, telekinesis, teleportation, opening portals) and many more.

Whereas hypnosis was introduced to European society in 18th century and it is sometimes described as black magic and dangerous for our body and spirit, because the person is just the victim on stage with implanted suggestion by hypnotist. If it's done incorrectly, the victim suffers nightmares and aberrant behaviour.
> 2 votes

# Answer
Both the terms hypnosis and meditation are nebulous terms and are incomparable. There are many Hypnotic States, including the one called 'waking state'. There are many ways to define a hypnotic state, one of them is having a single point of focus to the exclusion of all other stimuli. This would follow the definition of James Braid of 'Monoideaism'. This would also be similar to a meditative state brought about by focusing attention on one thing such as the breathe, heart beat or ringing of a bell.

However if you look at volunteers at a hypnotists stage show they are up walking around, hallucinating images, sounds and feelings, this looks nothing like meditation and yet they would be considered to be 'in hypnosis'.

If we look at self-hypnosis and compare that to meditation, they are similar. The states are similar the process to get into that state of trance is similar and how they are used to change the brain are similar.

The biggest difference I can see between self-hypnosis and meditation is that meditation is viewed as a fixed teaching coming from ancient practices where as hypnosis is a growing body of knowledge.

Other differences are: That hypnotists tend to use relaxation as a means to coax the mind to move from a defensive posture to a receptive posture while meditative practices cultivate focusing the mind on discarding or ignoring other stimuli.

Self hypnosis is goal specific orientated, the goal is to relax, take in a new suggestion or be in a state of repair. As a result of being goal orientated, self hypnosis can be trained by a hypnotist in a matter of minutes. Meditation from ancient practices in contrast, is intended to be a lifelong practice with skills built up the foundations of the previous skills and the benefits are non specific.
> 0 votes

# Answer
There is a clear answer in terms of the biblical model of psychology: they are exact opposites. There is body, soul, and spirit. Picture the soul as a garden, where experiences, thoughts and habits are planted and cultivated. The spirit is the gardener. In hypnotism, the spirit or gardener is put to sleep so someone else can temporarily come into the garden and plant seeds, dig up plants, etc. In meditation, the soul is put to sleep so the spirit can do some gardening. Most people are in a hypnotic state most of the time though, meaning their gardener is asleep on the job, so meditation serves to wake up the gardener. So it comes to the give a man a fish/teach him to fish metaphor. Hypnotism is getting a fish (or maybe a snake) and meditation is learning to fish. Also for closure in the garden metaphor, the body and external circumstances are the harvest from your garden.
> -1 votes

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# Question
Title: How did Hermann Ebbinghaus conduct memory experiments on himself?
I was reading about Hermann Ebbinghaus. He became interested in experimental psychology which led him to conduct memory experiments on himself which then resulted in the publication of his book: "Memory: A Contribution to Experimental Psychology" in 1885.

He discovered the forgetting curve and the spacing effect. How did he do so? I'm aware that he had a list of 2300 "nonsense syllables" to memorize but I have no idea what his process was like. Did he play with different intervals for the review of the material? Things like that. Is the process explained in the book?

I'd like to look at the details to see the connection between his work and the now available software employing spaced repetition algorithms.

# Answer
> 1 votes
Ebbinghouse indeed only tested on himself, limiting the generalization of his findings.

Your question is a really good one; given the time of his writing, the now so familiar structure of a standard journal paper (Abstract, Introduction, M&M, Results, Discussion) is not present in his monograph. However, tucked away in the text on p. 51 of 100 in this pdf version of his book he describes the following:

> The investigations in question fell in the year 1879-80 and comprised 163 double tests. Each double test consisted in learning eight series of 13 syllables each \[...\] and then in relearning them after a definite time. The learning was continued until two errorless recitations of the series in question were possible. The relearning was carried to the same point; it occurred at one of the following times, -- namely, after about one third of an hour, after 1 hour, after 9 hours, one day, two days, six days, or 31 days.

As far as I understand, hence, he learned a sequence of syllables and then he basically tried to re-learn those sequences after a series of fixed times and see how his scores were the second time.

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Tags: learning, memory, history-of-psychology, encoding, spaced-repetition
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# Question
Title: William James "Principles of Psychology" and Brain Plasticity
I am reading William James' "Principles of Psychology". It is clear in his research that he was acutely aware of brain plasticity and the limited capacity for a precise "schema" (ie. static brain map) to represent brain function. Seeing that this text is well over 100 years old and cites much research even older, how is it that I see so much information (primarily in the press and lay neurology texts) that brain plasticity is a new perspective recently discovered by academics and researchers? Without question the earliest modern neuroscientists knew about brain plasticity. It was an undeniable characteristic of their research. (As a side note, it is interesting that creatures with less intelligence have greater plasticity, with the level of intelligence being inversely proportional to plasticity. A fact I've never seen discussed.)

I feel I should mention that I am not a psychologist or neuro-scientist. I have a doctorate in Statistics. I did search academic papers and there are many papers that credit William James with describing plasticity under the heading "habit". So to my original question, why is it that plasticity is just being "discovered?"

An academic paper that clearly sites William James with being the first to introduce plasticity - https://fastertomaster.com/the-brain-that-changes-itself-norman-doidge/

A recent book that erroneously claims plasticity is a new concept - https://fastertomaster.com/the-brain-that-changes-itself-norman-doidge/

# Answer
**Short answer**
Neural plasticity is a broad term. While it has long been recognized, the fact that the adult brain is plastic even at the gross structural level has taken a long time to become widely accepted.

**Background**
There are a few things that play a role here.

* First and foremost, **neural plasticity** is a term encompassing many different processes. Neuroplasticity can be observed from microscopic (molecular) changes in individual neurons, to large-scale structural changes, such as cortical remapping in response to injury.
* Secondly, the small scale changes have long been recognized, the gross structural changes were only discovered much later.
* Thirdly, neuroplasticity has indeed been long recognized, but it has long been thought that there were critical periods in life (Sylva *et al*., 1997) where after plasticity was no longer present. In a way, that idea is still recognized, and is the reason why, *e.g.*, congenitally deaf children are receiving cochlear implants in the first months of their lives to allow the plastic brain to develop hearing and speech development during this "critical period" where these developments are accompanied by gross changes in the brain not possible later in life (Snik *et al.*, 1997). Untreated prelingual deafness therefore results in impaired speech understanding and the typical 'deaf speech' when they receive an implant after this critical period. Paul Bach-y-Rita and Michael Merzenich are often credited for their ideas on the plastic **adult brain**. For instance, Bach-y-Rita recognized that his dad, by then an aged man, was still capable to re-learn many tasks after serious brain injury. He recognized that hence, the adult brain is plastic too (plastic, in terms of gross changes that allow re-allocation of healthy brain tissue to take over the tasks from damaged regions). The idea of the adult brain being able for gross plastic changes has taken a while to become accepted.

<sub>**References**
**-** Snik *et al*., *Int J Ped Otorhinolayngol* (1997); **41**(2):121-31
**-** Sylva *et al*., *Br Med Bull* (1997); **53**(1): 185-19</sub>
> 2 votes

# Answer
The difference is that these days \- it is known that plasticity (mainly) occurs in the synaptic connections, \- the biophysical changes that implement the plasticity are known. \- this knowledge allows manipulating and blocking of memory formation.

For instance in the 60s is was still thought that memory was stored in DNA.
> 0 votes

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# Question
Title: Why are biosignals from the body said to be continuous?
Whether we talk about EEG, ECG or EKG aren't all these signals discrete as we are reading the voltages from the electrodes that are due to certain bio-chemical or bio-electrical activities. I do not get why people say that EEG is continuous and hence we need to convert it to digital when it is already digital.

# Answer
> 4 votes
Biological signals are analogues and hence continuous. Early EEG systems simply recorded the analogue signals and displayed it as a continuous signal graphically as wiggly lines written by little pens on a roll of paper (Fig. 1). Only after analogue-to-digital converters became available, could EEG signals and the likes be digitally sampled.

Fig. 1. Analogue EEG signal. source: Britton *et al.*, 2016)

**Reference**
**-** Britton *et al.*, Electroencephalography (EEG): An Introductory Text and Atlas of Normal and Abnormal Findings in Adults, Children, and Infants, 2016. Chicago: American Epilepsy Society

# Answer
> 1 votes
To add to the answer provided by @AliceD, pure digital waveforms are square waveforms as they represent steps between 1s and 0s and are therefore not continuous.

Analogue waveforms are not. They are smooth continuous waves and can represent many voltage points at each millisecond, microsecond or nanosecond between the peaks and troughs.

Outputs from ADCs (Analogue to Digital Converters) will have steps in them representing the various voltage ranges at their relative timings. In a sense they are digital outputs but are really a digitized version (a representation) of an analogue waveform through digital sampling of the wave voltage at the relevant millisecond, microsecond or nanosecond depending on the ADC timing (see the image below from https://www.allaboutcircuits.com/textbook/digital/chpt-13/practical-considerations-adc-circuits/).

# Answer
> -1 votes
I disagree with the other answers, to an extent. Biological signals are generally created by ion passing through a cell membrane. Each of these ions cause a tiny current/magnetic field which is too small to measure in most cases. Each cell action potential is made up of hundreds (???) of ions passing through the membrane at a variety of positions. Most measures of biological signals measure potentials from many cells. These cells are distributed in a non homogeneous extracellular matrix. At the limit the biological signals are discrete and made up of individual ions, but by the time we measure them, they are so mixed up that they are continuous.

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title: Percent change of a biophysical signal

text:
# Question
Title: Percent change of a biophysical signal
To calculate percent change the formula is: $\frac{Amount \\, ofchanges} {Original \\, amount}100=\frac{New−Old}{Old}100$

because we want to see how it changes compared to where it was before, now if there is no changes the percent changes must be zero. I am a student in neuroscience field, we always measure biophysical signals change (in our field we call it normalized signals, for example the signal that define the amount of blood in cerebral area), but these signals are always start from 1.

Is normalized value and the percent change are the same, and why start from 1 and not 0?

# Answer
Normalized values usually refer to a ratio, which is not the same as percent change.

Percent change is usually bad because increases and decreases aren't the same:

40 to 60 is a 50% increase. 60 to 40 is a 33% decrease. A 50% decrease from 60 would be 30. It gets especially complicated and unwieldy if you have multiple contributing factors.

Instead, I recommend taking logarithms and using differences between logarithms: then "0" means no change. Alternatively you can use ratios, which are the same as subtracting logarithms, but then you interpret no change as "1" because it's a ratio; x/x = 1, not zero. Logarithms are great because different additive factors act on the outcome as a product, but you can use linear statistics.
> 0 votes

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# Question
Title: Open access 7T resting-state fMRI dataset
I'm looking for an open access dataset of 7-tesla resting state fMRI images of human subjects. I've been able to find one so far (http://www.nature.com/articles/sdata201454). However, I need images that were acquired using MP-RAGE (not MP2-RAGE) sequencing. I've checked the major open neuroscience repos so far with no luck. Does anyone know of an open access dataset that meets this description?

# Answer
> 5 votes
There two 7 Tesla data sets currently publicly available, bith within the **OpenfMRI data collection**

Here is a link to a 350 GB data set for 20 subjects watching the audio version of Forrest Gump. The authors also have all the scripts available at Github to enable reproduction. The associate publication can be found here.

The other 7T data set you allready mentioned in your question. As far as I know there are only these two as of June 2016.

# Answer
> 2 votes
The Nighres project has released some 7T MRI datasets and tools to run them. You can read the paper on the tools here, and download the datasets from NITRC here.

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Tags: neuroimaging, fmri
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# Question
Title: Does rTMS therapy require medical licensing?
In my research project, besides sound and light therapies, I would like to experiment with rTMS (repetitive transcranial magnetic stimulation) on volunteers. I wonder if this requires medical licensing?

# Answer
> -1 votes
It depends on the country, but, for most of them (incl. USA and EU), you don't need a medical license to perform biomedical *research*, including human experiments with TMS. However, you will need legal approval, such as certified research environment, ethics/IRB permission, etc. Also, one should delineate research and clinical trials, which are governed by a special set of rules and, most often, require medical environment.

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# Question
Title: Why do solutions to problems feel simple (or obvious) once we are given them?
I was watching a video about one of the hardest maths problems even examined in the IMO (International Math Olympiad). And once I was walked through the solution, it seemed so obvious to me, as I'm sure it did for most people. It had a two step solution and was explained very intuitively.

Another example of this is whenever I watch a movie and replay the story line in my head afterwards, it always feels that the story line is predictable. Almost as if I could write it myself. When in essence it's not doubt difficult and I couldn't never predict it's plot line without seeing the entire film.

Given any outcome to an event (such the answer to a mathematical problem or the plot of a movie (or anything really), why do we feel as if it was so obvious?

Besides the throw-away answer of 'cockiness or 'arrogance', is there a physiological phenomenon for this sense of confidence/ know-how one may experience after being told the solution/end to something.

# Answer
The closest one that comes to mind is called the `Hindsight Bias`. Basically this means that things seem to be "more obvious" than it actually is--usually after the event had just happened.

Definition:

`Hindsight bias is a term used in psychology to explain the tendency of people to overestimate their ability to have predicted an outcome that could not possibly have been predicted. In essence, the hindsight bias is sort of like saying "I knew it!" when an outcome (either expected or unexpected) occurs - and the belief that one actually predicted it correctly.`

Usually coming up with the idea is difficult, for instance solving a math problem. The challenge is finding the right mental model to approach the problem, but once the solution or approach is presented to you, it may be easy to accomplish and you'd feel it was obvious.

Or it could be really just that predictable or that you're natural/good at the subject (e.g. Math) to begin with and it is easy for you.
> 1 votes

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# Question
Title: if IQ is inherited, is it from father or mother?
I think there is some research that IQ is inherited, but is it inherited more from the father, or mother, or both?

# Answer
Both. The Independent article used a blog post as its main source. The blog post (which is no longer online) claimed to rely on a doc (scientific document) that **actually** hardly supports its main assertion. What that doc **actually** found was that there are 41 genes on the X chromosome associated with mental retardation, and none on the Y chromosome, and many (but well under 41) such genes on each of the other 22 chromosomes. These autosomes had a total of 180 such genes. (My source for the doc) The doc then goes on to make a bunch of conclusions based on "assuming that these \[41\] genes are responsible for the development of general intelligence or cognitive abilities (‘g’ according to Plomin)", but this is a totally unwarranted assumption in my view. Oh, and the doc is in the Opinion section, so it's probably NOT peer-reviewed, which is why I call it a **doc** rather than a paper.
> 2 votes

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Tags: intelligence, iq, genetics
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# Question
Title: Is Carl Jung synchronicity scientific theory?
Do you know about **synchronicity theory** (Carl Jung) and what scientific work has been done and is it proven? (what common references)

Is it possible that it could be related to the **collective subconscious** if it is real? (Scientific common references)

Thanks.

# Answer
Synchronicity is an interesting philosophical idea; unfortunately there is no evidence that it actually exists. Therefore, there are some people who consider Jung's theory to be pseudoscientific.

> Robert Todd Carroll, in his book "The Skeptics Dictionary," notes that "even if there were a synchronicity between the mind and the world such that certain coincidences resonate with transcendental truth, there would still be the problem of figuring out those truths. What guide could one possibly use to determine the correctness of an interpretation?" There is no scientific or objective way to determine whether synchronicity is valid or not; it's all subjective personal opinion and experience and flexible definitions.

You can read more on this on this LiveScience webpage

I also commented on synchronicity within an article I wrote in May

> Many of Jung’s theories are considered to be pseudoscience. One example is synchronicity, his idea that meaningful connections in the world manifest through coincidence with no apparent causal link. This is what Jung referred to as the acausal connecting principle (Nickell, 2002). This is because these ideas culminated from his ideas about the paranormal. Despite his own experiments failing to confirm the phenomenon (Shermer & Linse, 2002) he held on to the idea as an explanation for apparent ESP (Jung, 2013).

## References

Jung, C. G. (2013). Synchronicity: An Acausal Connecting Principle. London: Routledge.

Nickell, J. (2002). “Visitations”: After-Death Contacts. Skeptical Inquirer 12(3) Retrieved from https://skepticalinquirer.org/newsletter/visitations\_after-death\_contacts/?/sb/show/visitations\_after-death\_contacts

Shermer, M. & Linse, P. (2002). The skeptic encyclopedia of pseudoscience (Vol. 1). Santa Barbara, CA: ABC-CLIO.
> 4 votes

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# Question
Title: What is the difference between hindsight bias and confirmation bias?
I'm trying to understand better the influence of psychological biases on the financial market decision-making process.

Wikipedia describes hindsight as follow:

> Refers to the common tendency for people to perceive events that have already occurred as having been more predictable than they actually were before the events took place. As a result, people often believe, after an event has occurred, that they would have predicted, or perhaps even would have known with a high degree of certainty, what the outcome of the event would have been before the event occurred.

While the definition of confirmation bias according to the same source is relatively similar:

> Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses.

I think that those biases differ from the results' reflection perspective. However, I'm a bit confused about the proper interpretation.

Thanks in advance.

# Answer
**Hindsight Bias** (Also known as the "knew-it-all-along phenomenon"), is the tendency when an individual assumes that he/she knew and predicted an outcome after the outcome has been determined (Hoffrage & Pohl, 2003). Due to that, it makes the individual believe that he/she could have predicted that outcome with statements such as: "I knew it all along" or "I knew it would happen" (Hoffrage & Pohl, 2003).

Hindsight bias functions in a way that after learning the outcome, it gives the individual a sense of predictability, a higher degree of certainty of the outcome without any prior knowledge. Having hindsight bias could potentially lead to people being overconfident on their ability.

As an example, consider a student who is answering a test question and is uncertain whether he should answer A or B. The student eventually answer B. When the teacher mentioned the actual answer is B. The student's first thing that came into his mind after the answer is mentioned: "I knew the answer is B all along". Making him feel confident about it despite the fact that he was uncertain about the answer during the initial stage on doing the test.

**Confirmation Bias** is the tendency for the individual to find and gather information that is more inclined and supports his/her beliefs (Nickerson, 1998). At the same time, ignoring the other possible alternatives of the information; making it biased.

Example, if a person strongly believes that playing games is harmful for children, he/she would find information/studies that supports the connotation that playing games is harmful. Without acknowledge or accept the fact there are also information/studies shown that it is beneficial for children to play games.

## References:

Hoffrage, U., & Pohl, R. (2003). Research on hindsight bias: A rich past, a productive present, and a challenging future. *Memory*, 11(4-5), 329–335. doi:10.1080/09658210344000080

Nickerson, R. S. (1998). Confirmation bias: A ubiquitous phenomenon in many guises. *Review of General Psychology*, 2(2), 175–220. doi:10.1037/1089-2680.2.2.175
> 6 votes

# Answer
Those sources seem like they have the correct descriptions and they are definitely different, I'm not too sure how to say more than them but I'll try to rephrase.

For hindsight bias, you are looking at a current result of something that happened, and looking further backward and saying "oh that was predictable" or "oh I would have guessed that".

Confirmation bias means that, for something you think is true today, you will more strongly recognize further evidence in favor of your opinion versus evidence against it in the future.
> 1 votes

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Tags: bias
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# Question
Title: what is the difference between mindfulness meditations and focusing on other things?
For example:
While I'm studying(or doing anything in my life), my brain wanders around(daydreams, stresses, remembers unpleasant memories and thinks negatively about the future) so I notice that and then bring it back to focus again in studying. Isn't that the same thing as mindfulness meditation? in both things, we focus on or attend to something and when the brain wanders around, we bring it back.
I read articles before   that say the difference is that in mindfulness, you let things(that you attended to) go after you finish without thinking about it again.
Does that mean that I can call studying a mindfulness meditation if I stopped thinking about it after finishing?

# Answer
> 3 votes
It is question I've been asking myself as well in my experience with mindfulness meditation.

Meditation is not manipulating experience, it is simple noticing it. Furthermore it focuses on sensory experience which seems to be inversely correlated with our narrative experience(Farb et al., 2007).

Being focused on studying involves planning and invariably it adds a narrative feature to our experience. Mindfulness increase grey matter in areas associated with executive control(Hölzel et al., 2011), hence we can hypothesize mindfulness is good for more effective studying.

There might some type of false placebo effect in studies reporting increased focus due to meditation.

Farb, N. A. S., Segal, Z. V., Mayberg, H., Bean, J., McKeon, D., Fatima, Z., & Anderson, A. K. (2007). Attending to the present: Mindfulness meditation reveals distinct neural modes of self-reference. Social Cognitive and Affective Neuroscience, 2(4), 313–322. https://doi.org/10.1093/scan/nsm030

Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research, 191(1), 36–43. https://doi.org/10.1016/j.pscychresns.2010.08.006

# Answer
> 2 votes
First, mindfulness meditation is a practice that involves attention regulation and adopting a particular orientation toward one's experiences in the present moment \[1\]. Your example has largely described the first component—paying attention to the current moment. The second component has been described as relating to one's experience within an orientation of curiosity, experiential openness, and acceptance. The consequences of this component include cultivating a non-reactive and non-judgmental attitude \[2\].

Second, there are formal mindfulness practices like mindfulness-based stress reduction (MBSR) program \[3\], and "informal" mindfulness practices namely mindfulness of everyday activities (e.g., mindful eating, mindful walking), mindful reading, in your case.

In short, mindfulness meditation cultivates focused attention, and focused attention is part of the practices involved in mindfulness meditation.

\[1\] Bishop, S. R., Lau, M., Shapiro, S., Carlson, L., Anderson, N. D., Carmody, J., ... & Devins, G. (2004). Mindfulness: A proposed operational definition. Clinical psychology: Science and practice, 11(3), 230-241.
\[2\] Baer, R. A., Smith, G. T., Hopkins, J., Krietemeyer, J., & Toney, L. (2006). Using self-report assessment methods to explore facets of mindfulness. Assessment, 13(1), 27-45.
\[3\] Kabat-Zinn, J. (1990). Full catastrophe living: using the wisdom of your body and mind to face stress, pain and illness. New York: Delacorte.

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Tags: attention, meditation, mindfulness
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# Question
Title: correction for multiple comparison over many ROIs
I would like to know how to correct a p value of a stiatistic when the same test was run over multiple regions of interest. The modality is MEG. So, I have 4 Regions Of Interests, and I ran the same cluster-based permutation test on the averaged timecourse of each ROI. I got more than 10 clusters, each with p \< 0.05, but how can I get the corrected p value considering there was more than one region?

Any help will be much appreciated.

# Answer
You have one p-values for each ROI timecourse (for the largest cluster) indicating whether your conditions are exchangeable. If you want to correct for the 4 ROIs you could use any adequate multiple comparison correction, from classical Bonferroni (which might be too conservative as the tests are likely not completly independent) to Benjamini-Hochberg style FDR correction (but applied to the cluster permutation test p-values).

This leaves us with the question which p-values count, one per ROI (the largest cluster, i.e. smallest p-value) or the p-values for all supra cluster-threshold clusters. I would think the former is more appropriate, as you already corrected for the multiple clusters.

That is, for the Bonferroni correction you would multiply your p-values by 4, (or identically, divide your critical alpha by 4).

This solution is incomplete, as I do not know how to get corrected p-values for the second largest cluster with FDR or Holm-Bonferroni.
> 2 votes

# Answer
I fully endorse Benedikt's answer. Further, you have to specify the question you are asking.

Let's say you want to know whether activity in a face recognition task differs between conditions in FFA, PPA, STS, and FEF and that the **location** of the difference is what you want to know, then Bonferroni is the correction of choice.

In case you ask the question whether the activity in the brain differs **somewhere**, but you do not care where specifically, then false discovery rate correction (FDR) is the method of choice.

The former allows statements like it is FFA and not STS, the latter allows statements like the conditions lead to differential activity in a collection of areas, whose identity is not too certain.
> 0 votes

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Tags: cognitive-neuroscience, methodology, eeg, statistics, meg
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# Question
Title: How to determine which scale to use: Nominal vs Interval?
I am currently working on immersion and how it can be quantified. One of the problems I have run into is how to determine which scale to use?

I have performed a literature review but have not obtained any insight. Since I do not know if immersion is a binary or graded experience, how should I decide on which scale to use?

Can I use an interval scale and then obtain nominal values from that? If yes, which methods are available?

I highly appreciate your help!

# Answer
I'd recommend an ordinal scale.

A nominal scale just labels classes without a \< or \> relation. Using this you would be limited to "immersive" and "not immersive" type of answers. This runs into the danger that experimental subjects might classify all your conditions as immersive or non-immersive respectively. That is, you might get little information.

An ordinal scale is a set of ordered levels with a \< or \> relation. A 5-point Likert scale like "not immersive at all / a little immersive / moderately immersive / highly immersive/complete immersion" would be an example. In case immersiveness is binary, it would show as all answers falling into only two levels of your scale. That is, you do not lose anything. As an experimental subject, I'd understand such instructions and a rating scale. This is what I'd take.

An interval scale requires a quantitative comparison. For example, the difference between 350ms and 370ms reaction time is as large as between 200ms and 220ms. For immersiveness I do not know of such a scale. Therefore it does not seem an option for you.

There is a further rational scale. But it is even more demanding.

A nice explanation of scales is on https://www.mymarketresearchmethods.com/types-of-data-nominal-ordinal-interval-ratio/
> 1 votes

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Tags: measurement, methodology, experiment-design
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# Question
Title: Research on Distribution of Enneagram Types in a Given Profession
I was in a conversation with an Enneagram scholar who claimed that certain Enneagram types are more likely to hold certain specific positions or have certain professions.

Is there any data or has there been any research published that has studied the Enneagram type distribution of fields or titles thought to be Enneagram-type-personality-specific?

Examples:

If we were to give the Enneagram test to ten-thousand nurses, would we find that a statistically significant number of them are Twos?

If we were to give the Enneagram test to ten-thousand career scientists, would we find that a statistically significant number of them are Fives?

# Answer
I myself have a long-standing fascination with the Enneagram system and believe it to be the most incisive and encyclopedic theories of human patterns I know. So, yes, I would say there are correlations with career-choice (as with essentially all behavior). I have one more specific comment about job-choice. But first, I'd like to enumerate two important caveats that apply here:

* Career choices (like many other important human choices - marriage, politics, etc.) are highly conditioned on background, education, opportunities perceived to be available, etc. - therefore, it is naive to expect overwhelming simplistic correlations. Type Five scientists? Type Eight policemen? Maybe - if one really investigated I suspect there would be evidence that the relative frequencies of these Type-job pairings exceed those expected based on frequencies of the Types in the population under study. But they might not be that much higher - there's just too much variability in our various life paths....

+ Formal research on the Enneagram is hamstrung in general terms by the lack of a simple, easy objective measure of Enneagram type. Yes, there are various (relatively) cheap-and-easy tests, available on-line and in book-form - but I don't think they are particularly accurate. There's too much at stake psychologically when people are being asked self-report questions, and many of use "game the system" in favor of how we'd like to be seen (even if tend we claim otherwise). This is based on 10+ years experience with hundreds of people coming through a public discussion-group I've run on the Enneagram.

Maybe someday there'll be an Enneagram test based on brainawaves (or whatever). Until then, I'd say, in our time, the better way to get into this system is to read a good book (any of the Risa and Hudson books are good places to start), and look and soberly deeply into yourself if you are so inclined. Then, if you take an abiding interest in the topic, and want to get more involved, try and find an Enneagarm-educted community with sincere people who can help validate (or challenge) your self-assessment. Once securely typed, you can really *know* how deeply and uncannily this system works in our lives - and curiosities like how the system relates to career-choices may not actually seem as important.

As mentioned above, I do have one more comment specifically on job-choice, however. Based on my own typing skills I once did a survey of a group of 100+ individuals many of whom I know well (my high school class) and attempted to correlate career-choice with Enneagram type. Interestingly, I found that the TYPE-WING actually seemed as strongly typed with career-fields chosen as the MAIN TYPE. Possibly, as individuals who express their main type in so many aspects of our lives, we unconsciously choose career-fields that help express our less-fully-expressed aspects as described by our type-wing. (Just a speculation.) More caveats: (1) TYPE-WINGS may be harder to diagnose properly than the main type itself; (2) I have somewhat different beliefs about what these TYPE-WINGS are than the ones described in the literature.

Sorry for the long-winded answer, that's just the territory as I see it. Please post any replies, and I will attempt to monitor this thread.
> -1 votes

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Tags: personality, data, correlation
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# Question
Title: Does evidence support Maslow's Hierarchy of Needs?
Maslow's Heirarchy of Needs (shown below) is a popular concept and is often taught in basic psychology courses, and often less objectively taught in Business and Marketing courses.

A common problem with Maslow's Hierarchy is the difficulty of testing the theory and the ordering and definition of needs.

The Wikipedia article and most general sources about the topic do not discuss experimental tests regarding the Hierarchy nor am I familiar with any despite the theory's popularity.

**What research exists that investigates Maslow's Hierarchy directly?**

# Answer
> 40 votes
Its abstract says:

> The uncritical acceptance of Maslow's need hierarchy theory despite the lack of empirical evidence is discussed and the need for a review of recent empirical evidence is emphasized. A review of ten factor-analytic and three ranking studies testing Maslow's theory showed only partial support for the concept of need hierarchy. A large number of cross-sectional studies showed no clear evidence for Maslow's deprivation/domination proposition except with regard to self-actualization. Longitudinal studies testing Maslow's gratification/activation proposition showed no support, and the limited support received from cross-sectional studies is questionable due to numerous measurement problems. The difficulties with testing the theory are discussed and the conceptual, methodological, and measurement problems of the studies reviewed are detailed. The implications of the findings and future directions for research are outlined.

# Answer
> 22 votes
Neher (1991, FREE PDF) summarises and critically evaluates the theory. From the abstract:

> This critique of Maslow's theory of motivation examines all of its major components. The theory is summarized and its basic propositions are analyzed in the light of internal logic, other relevant theories, and related research. This examination points up many deficiencies in Maslow's theory, which enjoys wide acceptance, especially among humanistic psychologists. Suggestions are made regarding modifications to the theory that would remedy many of its more serious problems but at the same time preserve its perceptive insights.

### References

* Neher, A. (1991). Maslow's theory of motivation: A critique. Journal of Humanistic Psycholgoy, 31, 3. FREE PDF

# Answer
> 18 votes
# TL;DR: tons of support (and complications) at each level. One sequence can't fit all (it didn't claim to), but it makes sense in general, and so do the exceptions, and so do other motive models.

Check out Kenrick and colleagues' (2010) recent article. Kenrick is a prominent evolutionary psychologist; he and his colleagues have "renovated" Maslow's motive hierarchy based on a little bit of everything, including evolutionary, biological, personality, social, and cultural psychology. It's got some speculative theoretical claims of its own, but offers a deep review of empirical research too, and attempts to synthesize them. I'll just quote some of the parts that reference other research here (without vouching that all of it is necessarily original or empirical) to give you a sense of where else you might look beyond this article itself, and how Kenrick and colleagues summarize their basic findings directly. They go much further than direct summary though, so as other answers here have noted, there are many alternatives to Maslow's (1943) original theory, including this one!

# Kenrick and colleagues' (2010) model

> An **updated** hierarchy of fundamental human motives...integrates ideas from life-history development with Maslow’s classic hierarchy...adds **reproductive goals**, in the order they are likely to first appear **developmentally**...\[and\] depicts the later developing goal systems as **overlapping** with, **rather than completely replacing**, earlier developing systems. Once a goal system has developed, its activation will be triggered whenever relevant **environmental cues** are salient. \[Emphasis added.\]
>
> The overlapping triangles...explicitly reflect...that later developmental needs and goals add to, rather than replace, existing ones...
>
> ## Summary of Developmental Level of Analysis
>
> Developmental...life-history theory suggest\[s\]...revisions to Maslow’s original hierarchy...Three later-developing reproduction-focused goals of mate acquisition, mate retention, and parental care...different motives in the hierarchy continue to operate alongside those that develop later in life...reflected visually by the overlapping triangles...Important individual differences in motivational priorities...result from interactions between development and current environment...
>
> ## Conclusion
>
> Developments \[in\] evolutionary biology, anthropology, and psychology...suggested...structural modifications to Maslow’s classic hierarchy of human motives...The ultimate functions of behaviors and of life-history development \[suggest\] explicit inclusion of motivational levels linked to mating and reproduction. Reproduction...is not ultimately about self-gratification, but involves a considerable diversion of resources away from selfish goals and toward other\[s\]...Life-history trade-offs also \[imply\] that later developing motive systems never fully replace earlier ones...they continue to coexist, ready to be activated depending on current opportunities and threats in the environment, in interaction with individual differences. Thus...the ongoing dynamic interaction between internal motives and their functional links to ongoing environmental threats and opportunities.

**See also Table 1. How Different Motivational Systems Are Triggered by Proximate Cues and Individual Differences Linked to Fundamentally Important Threats and Opportunities.**

Obvious critique: some healthy people don't want kids, a mate, or even sex. I bet Kenrick would call them rare expressions of individual variations that society maintains to round itself out in adaptive or reactive ways. I've also covered some other perspectives in this answer to a related question of social needs.

## General themes from the rest of the article:

* **Support for existence of many underlying mechanisms associated with each level**
    + Some mechanisms are not definitionally tied to any one level.
* **Developmental, sociocultural, and individual differences in the order of emergence**
    + Maslow (1943) anticipated this, and presented his ordering as a general trend, not an inflexible, absolute sequence.

**References**

Kenrick, D. T., Griskevicius, V., Neuberg, S. L., & Schaller, M. (2010). Renovating the pyramid of needs contemporary extensions built upon ancient foundations. *Perspectives on Psychological Science, 5*(3), 292–314. Available online, URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161123/. Retrieved January 30, 2014.

Maslow, A. H. (1943). A theory of human motivation. *Psychological Review, 50*(4), 370–396. Available online, URL: http://downloads.joomlacode.org/trackeritem/5/8/7/58799/AbrahamH.Maslow-ATheoryOfHumanMotivation.pdf. Retrieved January 30, 2014.

# Answer
> 13 votes
The hierarchy of needs is an observation made by Maslow. It's generally assumed as the model to go by because most people can agree with the list and its order. Therefor it's no longer just a hypothesis, it's a theory.

A quick Google search brings me to this online book: http://www.scribd.com/doc/8703989/Maslows-Hierarchy-of-Needs-A-Critical-Analysis

That you can read for free. I glanced several pages of it and it's basically a critical look at the model, Maslow's life and the implications of the model on the individual and society as a whole.

On page 79, an update to the model is proposed:

# Answer
> 5 votes
While many consider Maslow’s hierarchy of needs to be pseudoscientific, there is a paper which suggests there is empirical support for the theory.

> Maslow's hierarchy of basic human needs provides a major theoretical framework in nursing science. The purpose of this study was to empirically test Maslow's need theory, specifically at the levels of physiological and security needs, using a hologeistic comparative method. Thirty cultures taken from the 60 cultural units in the Health Relations Area Files (HRAF) Probability Sample were found to have data available for examining hypotheses about thermoregulatory (physiological) and protective (security) behaviors practiced prior to sleep onset. The findings demonstrate there is initial worldwide empirical evidence to support Maslow's need hierarchy (Davis-Sharts, 1986).

## References

Davis-Sharts, J. (1986). An empirical test of Maslow's theory of need hierarchy using hologeistic comparison by statistical sampling. *Advances in Nursing Science, 9*(1), 58-72. doi: 10.1097/00012272-198610000-00008

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Tags: cognitive-psychology, motivation
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# Question
Title: Analyzing EEG time-frequency data in a factorial design
I am trying to find the best strategy to analyze a set of EEG time-frequency data from 24 subjects, using 64 electrodes. This is an exploratory study as I have no a-priori hypothesis on where or when changes in two frequency bands might be observed. In this case I have found that using non-parametrical statistical testing might be the best soulution: in particular, cluster-based permutation testing is widely used in cognitive electrophysiology.

However this approach is not feasible as I have a 2X2X2 within subject design, and it is not possible to look at interaction with permutation testing. On the other hand, running an ANOVA on the whole data-set might well result in an high number of false positives.

A solution to my proble might be to define ROI(s), so to perform ANOVA(s) on a limited number of electrodes within a time window. However I have no clue on how to define such ROI(s).

What is the best strategy according to you?

# Answer
> 1 votes
It is possible to look at within-subject interactions using cluster permutation tests. I.e. Eric Maris here: https://mailman.science.ru.nl/pipermail/fieldtrip/2011-January/003447.html

2x2x2 with factors A,B,C has 4 interactions AxB, AxC, BxC and AxBxC and 8 cells

```
+--------+-------------+-------------+
| C = 0  |    B = 0    |    B = 1    |
+--------+-------------+-------------+
| A = 0  | A0 B0 C0    | A0 B1 C0    |
| A = 1  | A1 B0 C0    | A1 B1 C0    |
+--------+-------------+-------------+

+--------+-------------+-------------+
| C = 1  |    B = 0    |    B = 1    |
+--------+-------------+-------------+
| A = 0  | A0 B0 C1    |  A0 B1 C1   |
| A = 1  | A1 B0 C1    |  A1 B1 C1   |
+--------+-------------+-------------+

```

2-way: You calculate the difference of differences at the average of missing factor:

$$ interaction\_{AB} = \frac{interaction\_{AB\_{c=0}} + interaction\_{AB\_{c=1}}}{2} = \frac{(A\_0B\_0C\_0-A\_1B\_0C\_0)- (A\_0B\_1C\_0-A\_1B\_1C\_0) + (A\_0B\_0C\_1-A\_1B\_0C\_1)- (A\_0B\_1C\_1-A\_1B\_1C\_1)}{2} $$

and for the three way interaction is the difference of interactions $$ interaction\_{AB\_{c=1}} - interaction\_{AB\_{c=0}} $$ (or any of the other pairs, same result)

I wrote a small script that confirms this:

```

library(tidyverse)
library("ANOVApower")

# simulate simple 2x2x2 design
design_result <- ANOVA_design(design = "2w*2w*2w",
                              n = 10,
                              mu = c(1:8),
                              sd = 1.0,
                              labelnames = c("A",0,1,"B",0,1,"C",0,1))

d = design_result$dataframe
contrasts(d$A) = c(-.5,.5)
contrasts(d$B) = c(-.5,.5)
contrasts(d$C) = c(-.5,.5)

# Cool, the ANOVApower script already gives us a unique column for each cell
# we can forget about subject because everything is balanced :)
d_cell = d%>%group_by(cond) %>%
  summarise(y = mean(y))

d_interactions = d_cell %>% summarise(
                     AB_C0 = (y[cond=='A_0_B_0_C_0']-y[cond=='A_0_B_1_C_0']) - (y[cond=='A_1_B_0_C_0']-y[cond=='A_1_B_1_C_0']),
                     AB_C1 = (y[cond=='A_0_B_0_C_1']-y[cond=='A_0_B_1_C_1']) - (y[cond=='A_1_B_0_C_1']-y[cond=='A_1_B_1_C_1']),
                     AC_B0 = (y[cond=='A_0_B_0_C_0']-y[cond=='A_0_B_0_C_1']) - (y[cond=='A_1_B_0_C_0']-y[cond=='A_1_B_0_C_1']),
                     AC_B1 = (y[cond=='A_0_B_1_C_0']-y[cond=='A_0_B_1_C_1']) - (y[cond=='A_1_B_1_C_0']-y[cond=='A_1_B_1_C_1']),
                     CB_A0 = (y[cond=='A_0_B_0_C_0']-y[cond=='A_0_B_1_C_0']) - (y[cond=='A_0_B_0_C_1']-y[cond=='A_0_B_1_C_1']),
                     CB_A1 = (y[cond=='A_1_B_0_C_0']-y[cond=='A_1_B_1_C_0']) - (y[cond=='A_1_B_0_C_1']-y[cond=='A_1_B_1_C_1'])
)

d_2way = d_interactions %>% summarise(AB = (AB_C0 + AB_C1)/2,
                             AC = (AC_B0 + AC_B1)/2,
                             BC = (CB_A0 + CB_A1)/2)

d_interactions$AB_C0 - d_interactions$AB_C1
d_interactions$AB_C1 - d_interactions$AB_C0

# confirm with linear model results
lm(y~A*B*C,d)

```

Which returns:

```
> d_2way
# A tibble: 1 x 3
      AB     AC    BC
   <dbl>  <dbl> <dbl>
1 -0.683 -0.827 0.129

```

```
> d_interactions$AB_C1 - d_interactions$AB_C0
[1] 1.307831
> d_interactions$AB_C1 - d_interactions$AB_C0
[1] 1.307831

```

```
> lm(y~A*B*C,d)

Call:
lm(formula = y ~ A * B * C, data = d)

Coefficients:
(Intercept)           A1           B1           C1        A1:B1        A1:C1        B1:C1     A1:B1:C1
     4.3853       3.8473       1.8056       1.1670      -0.6832      -0.8272       0.1288       1.3078

```

Identical results.

This is what I would do

# Answer
> 0 votes
This scenario is practically unsolvable. If one doesn't have any assumptions about when, where, and how the changes may occur, then for 24 subjects (typically in this business, with high inter-subject variance due to age, sex, etc.) x 64 channels (usually, with variable SnR) x 45 frequencies (each signal exists in the frequency space of 1 to 45 Hz, at least) x some\_cognitive\_states\_or\_tasks you have an insane number of alternatives. It will take equally insane statistical power (i.e., amount of evidence) to prove any effect. The expected effect size on the field of cognitive neuroscience is below Cohen d \< 1 (see, 10.1371/journal.pbio.2000797), so even if you have it somewhere, it will not be statistically significant.

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Tags: cognitive-neuroscience, eeg
---