What are the negative effects of meditation? I see lots of articles touting the benefits of meditation. But what are the bad things about it? Maybe if a person has to make quick decisions, meditation would not be a good thing? This could be similar to a paridigm of "Thinking Fast, Thinking Slow" by Kahneman.

The adverse effects of meditation as reported in scientific studies are as follows:

relaxation-induced anxiety and panic
paradoxical increases in tension
less motivation in life
boredom
pain
impaired reality testing
confusion and disorientation
feeling 'spaced out'
depression
increased negativity
being more judgmental
feeling addicted to meditation
uncomfortable kinaesthetic sensations
mild dissociation
feelings of guilt
psychosis-like symptoms
grandiosity
elation
destructive behavior
suicidal feelings
defenselessness
fear
anger
apprehension
despair
increased false-memory susceptibility

Also, anecdotal evidence suggests that meditation can worsen symptoms of some psychiatric problems.

Sources:

Study from 1992:
http://www.ncbi.nlm.nih.gov/pubmed/1428622

  Adverse effects of meditation: a preliminary investigation of
  long-term meditators, by Shapiro DH Jr.

  Department of Psychiatry and Human Behavior, California College of Medicine, University of California, Irvine.

  Abstract

  Adverse effects of meditation were assessed in twenty-seven long term
  meditators (average 4.27 years) both retrospectively (time one) and
  prospectively at one month (time two) and six months (time three)
  following a meditation retreat. At both time one and time three
  subjects reported significantly more positive effects than negative
  from meditation. However, of the twenty-seven subjects, seventeen
  (62.9%) reported at least one adverse effect, and two (7.4%) suffered
  profound adverse effects. When subjects at time one were divided into
  three groups based on length of practice (16.7 months; 47.1 months;
  105 months) there were no significant differences in adverse effects.
  How the data should be interpreted, and their implications both for
  the clinical and psychotherapeutic use of meditation as a
  relaxation/self-control strategy, and as a technique for facilitating
  personal and spiritual growth, are discussed. Limitations of the study
  and suggestions for future research are also offered.

Meta-analysis from 2000:

  Meditation: concepts, effects and uses in therapy by Alberto
  Perez-De-Albeniz and Jeremy Holmes

  International Journal of Psychotherapy, Mar2000, Vol. 5 Issue 1,
  p49, 10p

  Abstract: This article reviews 75 scientific selected articles in the
  field of meditation, including Transcendental Meditation among others.
  It summarizes definitions of meditation, psychological and physiological
  changes, and negative side-effects encountered by 62.9% of meditators
  studied. While the authors did not restrict their study to TM, the
  side-effects reported were similar to those found in the "German
  Study" of Transcendental Meditators: relaxation-induced anxiety and
  panic; paradoxical increases in tension; less motivation in life;
  boredom; pain; impaired reality testing; confusion and disorientation;
  feeling 'spaced out'; depression; increased negativity; being more
  judgmental; feeling addicted to meditation; uncomfortable kinaesthetic
  sensations; mild dissociation; feelings of guilt; psychosis-like
  symptoms; grandiosity; elation; destructive behavior; suicidal
  feelings; defenselessness; fear; anger; apprehension; and despair.

New study shows increase in cortisol reactivity (a biological marker of stress): http://www.ncbi.nlm.nih.gov/pubmed/24767614

  The present study provides an initial indication that brief
  mindfulness meditation training buffers self-reported psychological
  stress reactivity, but also increases cortisol reactivity to social
  evaluative stress. This pattern may indicate that initially brief
  mindfulness meditation training fosters greater active coping efforts,
  resulting in reduced psychological stress appraisals and greater
  cortisol reactivity during social evaluative stressors.

Another new study shows increased susceptibility to false memories:

http://pss.sagepub.com/content/26/10/1567

Increased False-Memory Susceptibility After Mindfulness Meditation by Brent M. Wilson, Laura Mickes, Stephanie Stolarz-Fantino, Matthew Evrard and Edmund Fantino in Psychololgical Science

  Abstract

  The effect of mindfulness meditation on false-memory susceptibility
  was examined in three experiments. Because mindfulness meditation
  encourages judgment-free thoughts and feelings, we predicted that
  participants in the mindfulness condition would be especially likely
  to form false memories. In two experiments, participants were randomly
  assigned to either a mindfulness induction, in which they were
  instructed to focus attention on their breathing, or a mind-wandering
  induction, in which they were instructed to think about whatever came
  to mind. The overall number of words from the Deese-Roediger-McDermott
  paradigm that were correctly recalled did not differ between
  conditions. However, participants in the mindfulness condition were
  significantly more likely to report critical nonstudied items than
  participants in the control condition. In a third experiment, which
  tested recognition and used a reality-monitoring paradigm,
  participants had reduced reality-monitoring accuracy after completing
  the mindfulness induction. These results demonstrate a potential
  unintended consequence of mindfulness meditation in which memories
  become less reliable.

Official recommendations in the US:
http://nccam.nih.gov/health/meditation/overview.htm#sideeffects

  Side Effects and Risks

  Meditation is considered to be safe for healthy people. There have
  been rare reports that meditation could cause or worsen symptoms in
  people who have certain psychiatric problems, but this question has
  not been fully researched. People with physical limitations may not be
  able to participate in certain meditative practices involving physical
  movement. Individuals with existing mental or physical health
  conditions should speak with their health care providers prior to
  starting a meditative practice and make their meditation instructor
  aware of their condition.


Can hallucinogens treat depressive states? Given the serotonin hypothesis of depression, increasing synaptic serotonin level may cause anti-depressive effects.

Hallucinogens seems to have such advantages:

They improve mood at once, but not after a while as SSRI. So hallucinogens may actually act faster.
There are more types of hallucinogens, then there are SSRIs. They have a wider pharmacological effect on serotonin receptors than antidepressants do.

So the questions are:

Are hallucinogens anti-depressive agents?
Which are their advantages and problems in comparison with modern antidepressants?

Most of the 'true' hallucinogens are classified as 5HT2A agonists. 5HT2A is a postsynaptic serotonin receptor. Serotonin-specific reuptake inhibitors (SSRIs) on the other hand act by increasing serotonin (5HT) levels in the brain, which in turn activates presynaptic 5HT1A receptors. Due to a continuous stimulation of these 5HT1A receptors they become downregulated (Hjorth et al., 2000).

5HT1A receptors are crucial for the negative feedback loop that controls 5HT release from the raphe nucleus neurons. When they release 5HT, they will postsynaptically activate a myriad of targets, but also presynaptically activate 5HT1A receptors, which inhibit 5HT release. Continuous 5HT1A receptor stimulation through SSRIs downregulates the 5HT1A receptors, thereby disrupting the negative feedback and resulting in a continuous, disinhibited flutter of 5HT release, in turn leading to overall elevated 5HT in the brain and suppression of depressive symptoms (Hjorth et al., 2000).

Among the most well-known 'true' hallucinogens we have LSD, mescaline, psylocibin and dimethyltryptamine (DMT). All of these are thought to act as 5HT2A antagonists (Nichols & Sanders-Bush, 2001) and do not elevate mood. Although they may induce euphoria, they may well induce a state of terror as well, dependent on the nature of the 'trip', which heavily depends on the acute mental state of the person ingesting the drug.

The one class of hallucinogenic drugs that may act as an antidepressant from a neuropharmacologic point of view is MDMA (ecstacy) and related compounds (MDA, MDEA etc). These drugs can, arguably, be classified as a hallucinogenic, although their hallucinogenic properties are far less pronounced as compared to mescalin and LSD. MDMA and related compounds evoke massive 5HT release, among other effects and induce acute euphoria, and virtually never dysphoria seen with the 'true' hallucinogens. However, after the effects wear off, a backlash typical for these drugs may be experienced, reminiscent of a dysphoric state associated with a burning out of the 5HT in the brain. Therefore, its effects are too transient to be classified as antidepressant. Long-term MDMA use is associated with brain damage (Fisher et al., 1995). Short-term euphoria is also seen with dopamine-agonists like amphetamine, meth and cocaine, drugs associated with even more severe comedown ('crash') after the effects wear off.

To wrap up, and answer your questions:

1) Are hallucinogens anti-depressive agents? - No.

2) Which are their advantages and problems in comparison with modern antidepressants? - They act too shortly by inducing a few hours of euphoria, after which a period of dysphoria follows. Long-term use of MDMA and related compounds will lead to insomnia,  addiction, and brain damage which are unwanted side-effects. Hence, these illicit compounds are not suitable for replacement of regular antidepressants.


Best meditation techniques to overcome Behavioral Addictions? Meditation seems to be one of the top techniques recommended nowadays for self-development (e.g. McGonigal, K. 2011). For people who want to overcome behavioural addictions (i.e. any "addiction that involves a compulsion to engage in a rewarding non-drug-related behavior – sometimes called a natural reward", such as food, sex, masturbation, pornography, gambling, internet, video games, nail biting, compulsive skin picking, compulsive hair pulling, etc.):

Which meditation techniques (e.g. mindfulness, Vipassana, Yoga, Zazen, TM, Kundalini, etc.) are the most recommendable, according to state-of-the-art Psychology and Neuroscience?
Additionally, given the fact that an average layman cannot afford going full-time monk, what would be a recommendable frequency of the practice (in terms of minutes/hours per day) to see palpable results in a reasonable time?

Furthermore:

Is a single meditation technique enough to overcome behavioral addictions? Or would it better to practice multiple meditation techniques at the same time? Or maybe different meditation techniques for different situations? For instance, are there any special meditation techniques to handle strong, compulsive urges in the presence of addiction cues/triggers?

Finally:

Is meditation as a whole enough, or would one need to complement it with other non-meditative practices or measures? For example, positive affirmations, hypnosis, or maybe going to a therapist, exercising, sleeping 8+ hours, etc. I'm just throwing some ideas around.

References

McGonigal, K. (2011). The willpower instinct: How self-control works, why it matters, and what you can do to get more of it. Penguin Books.

Several years ago, I was unsuccessfully searching for a study that evaluates the efficacy of many different interventions in the context of addictions. However, I did find a cognitive behavioral therapy (Copeland et al. 2001) that included a mindfulness technique called urge surfing and it was compared to other CBT interventions in cannabis use disorders. A definition follows from Marlatt (2002):

  Other clients have described the successful use of "urge surfing" as a
  mindfulness technique (Marlatt, 1985, 1994). Clients are taught to
  visualize the urge as an ocean wave that begins as a small wavelet and
  gradually builds up to a large cresting wave. As the urge wave grows
  in strength, the client's goal is to surf the urge by allowing it to
  pass without being "wiped out" by giving into it. I tell clients that
  urges are often conditioned responses triggered by cues and high-risk
  situations. Like a wave, the conditioned response grows in intensity
  until it reaches a peak level of craving. Giving in to the urge when
  it peaks only serves to further reinforce the addictive behavior. Not
  acting on the urge, on the other hand, weakens the addictive
  conditioning and strengthens acceptance and self-efficacy. Like any
  skill, learning how to "urge surf" takes practice and improves over
  time as the client attains greater balance on the mindfulness
  surfboard.

Copeland et al. mention the use of urge surfing in their program:

  The second session discussed urge management strategies such as‘‘urge
  surfing’’ and nonreinforcement.

and reported

  significantly better treatment outcomes than those receiving
  notreatment. They were more likely to report abstinence during the
  follow-up period, were significantly less concerned about their
  control over cannabis use (as measuredby the SDS), and were more
  likely to have significantly fewer cannabis-related problems than
  those in the delayed treatment control group. Further, those receiving
  six sessions of treatment significantly reduced their level of
  cannabis consumption. These outcomes were unaffected by the therapist
  delivering the intervention, but were affected by treatment
  compliance.

Note that the study included a lot of other lessons. Regarding how often it should be done: The subjects were advised to use this technique whenever the urge appeared.

More info about urge surfing can be found in the freely accessible book Cognitive behavior therapy: Applying empirically supported techniques in your practice (2003) in Chapter 67.

Regarding the question about lifestyle factors, there have been countless studies (some cited in McGonigal's book) that indicate a positive effect of cardiovascular exercise, sufficient sleep, low-glycemic diets on self-regulation and so I will not cite them here.

Sources

Copeland, J., Swift, W., Roffman, R., & Stephens, R. (2001). A randomized controlled trial of brief cognitive–behavioral interventions for cannabis use disorder. Journal of substance abuse treatment, 21(2), 55-64. doi:10.1016/S0740-5472(01)00179-9

Marlatt, G. A. (2002). Buddhist philosophy and the treatment of addictive behavior. Cognitive and Behavioral Practice, 9(1), 44–50. doi:10.1016/s1077-7229(02)80039-6

Lloyd, A. (2003). Urge Surfing. In W. O'Donohue, J. E. Fisher & S. C. Hayes (Eds.), Cognitive behavior therapy: Applying empirically supported techniques in your practice (pp. 451-455). New York: John Wiley & Sons Inc.


Does the retina contribute in distinguishing lines and borders? I think there is a phenomenon behind the way which our eyes judge between lines of contrast, like black lines on a white page, by just recognizing the contrast areas at the level of the rods and cones. I don't understand how this phenomenon works in the retina.

Short answer
Yes, retinal circuitry enhances the perception of contrast.

Background
In the retina, the neurons that guide the visual signal to the brain, the retinal ganglion cells (RGCs), process contrast. The receptive fields (RFs) of these cells exhibit a so-called center-surround organization (Fig. 1). They integrate the signal from multiple cones in the retina. ON RGCs fire when their RF is illuminated in the center (the central cone in the retina in the RF is illuminated) and they are inhibited when their surround is illuminated. OFF-center RGCs do the reverse. Together this organization results in sharpening of contrasts and aids in the coding of edges and contours. Midget cells also have RFs like this.

Remember that the retina is considered a part of the central nervous system by some. Thi because of its embryological origins, but also because of its complexity.

Note that further processing of contrast and edges occurs in the primary visual cortex (V1) (Schmolesky, 2002) and that awareness of that contrast information, i.e., the perception of edges, patterns and objects within the visual field occurs at high-tier associative cortices (Lorreys, 2005).

Center-surround RFs in RGCs. ON cells (left) fire when illuminated in the center, and are inhibited when illuminated in the surround. OFF cells have a reversed pattern (right). source: Stanford University

References
- Lorreys, Trends Cogn Sci (2005); 9(12):556-9
- Schmolesky, Webvision, The Organization of the Retina and Visual System, Kolb et al. (eds). Utah University


How to induce procrastination in an online experiment? I am designing an experiment to evaluate potential interventions for reducing procrastination. I am hence looking for one or more tasks to induce procrastination in an online experiment with participants recruited from Amazon Mechanical Turk. Real world tasks associated with procrastination tend to feel meaningless, taxing, unpleasant, frustrating, or boring, and they are often unstructured such that people don't know how to begin, and are unsure about whether and how they are going to succeed.

I have piloted a vigilance task because it is known to be boring but it was insufficient to induce procrastination in people working on Mechanical Turk. Can you think of any more suitable tasks that have some of the characteristics listed above?

Present subjects with a long-form writing task about anything - most likely, you'd be best-off supplying a topic that's difficult to write about (self-analysis, distant dates, self-assumed tardiness, etc) and not fun to think about. Don't set a time limit or a word limit, and stress that it's important they answer fully, completely, and honestly. If you want best results, you should aim to have a secondary control question that's meant to be easy to reply to, or relaxing, or ultimately nice to think about. Maybe pick "The best time of your life" vs. "The absolute worst time of your life".

Then provide them with a procrastinatory task. If you have access to the room they'd be doing this in, provide something hard to notice on first go, but actively distracting - for example, a Spanish soap opera on mute. Up to you on behavioral protocol here - you could watch it while you wait (and risk influencing the subject to watch it too), not appear to notice it, etc. Your goal at this stage is to be able to measure the time spent not working on the task - you might want to make notes of when they look away, create a program that records exactly how much time is spent not inputting data, etc.

You can also choose to make the testing separate and instead only give a single type of test (easy/hard) to a single person, and that person's procrastination responses are recorded. Etc.

The important thing to remember is that you don't need to invoke the purest sense of boredom or negative emotion to make a subject procrastinate; you only need to gently invoke procrastinatory emotions, and then provide a suitable distraction.


After how much time should we review a particular study material after once studying it thoroughly so as to retain it longer? I am having some doubts regarding my study regime; I am wondering if psychology could help?

So,I studied this one chapter thoroughly and due to shortage of time, I didn't review it for another 2-3 weeks. When I sat down to solve the related problems after 2-3 weeks, I didn't have that confidence anymore and I faced difficulty in attempting the problems that I was very comfortable with 2-3 weeks ago.This happened many times and it is spoiling all my hard work and is affecting my grades.

Is there a specific time interval after which you must review things after first learning them so that you can retain them longer?

How many times should I review it before I could remember it for an extended period of times(at least 5-6 months) ?

What percentage of a particular study material could I forget after not reviewing it for 2-3 weeks?

How much time does our brain take to forget things?

I know that it is always easier to learn a material second time than it is to learn for the very first time. It is because every bit of that information is somewhere stored in our subconscious memory. But, still how much time it should take for me to gain the same amount of confidence about that chapter as I had a couple of weeks ago?

Memory is a complex phenomenon with a number of variables for which we don't have yet the whole picture, let alone specific recommendations, a lot of research is also disputed since we tend to be different from human to human, perhaps that is why it hasn't been used in academia,i.e. we don't teach how to learn. Having said that here's a brief overview of your situation.
The first step is information encoding, a number of variables are at play here, but in short: "The retention of briefly presented information depends on past experience,context, and it's perceived importance"1, very little information is new ( you are not re-learning the periodic table every time you are presented with a new molecule), rather you are learning a new association and your physical situation (like where you are, distractions, motivation,emotional state, stress levels) influence the process.
The second step is information consolidation, that is transferring your newly formed associations from a short term memory to a longer term storage, a continual process. Any new conflicting information will negatively impact this first short( day to day)  to medium (weeks) bridge.Sleep: (non REM,slow wave or even naps) after information encoding seem to be both critical and helpful at this stage, diet,stress levels and lack of sleep work against this process.2

Is there a specific time interval after which you must review things after first learning them so that you can retain them longer?

Caveat emptor: A quirk of human memory, specially during early consolidation, is that retrieval ( or rehearsal ) alters the state of previously stored information, so an incorrect rehearsal session has the probability of affecting you previously well formed memories.3
Beyond that and previously mentioned variables, the consensus seems to be:

Rehearsals are only effective if they involve successful retrieval, in other words, if you can't remember the lesson, you are mostly at square one4 and need to relearn.
Number of successful repetitions (rehearsals) increases chance of recall.
The optimal spacing strategy is  as far apart as possible.
Each successful retrieval/rehearsal gives you a cumulative bonus.

How many times should I review it before I could remember it for an extended period of times(at least 5-6 months) ?

Memory in general stabilizes 3 to 5 years after the acquisition period3.2 ( so as many times as possible during that time based on the above recommendations seems reasonable) with the emphasis that (another memory quirk)  in a process similar to how it is originally stored and rehearsed for consolidation, it becomes easier to recall something as you try to retrieve it.5

What percentage of a particular study material could I forget after not reviewing it for 2-3 weeks?

Depends on the aforementioned initial encoding and subsequent stabilization plus the particular study material, ( is it a list of elements, a concept, a multi step process).In general memory tasks with unique multivariate associations (mnemonic devices for instance) fare better than less complex or even similar/competing memories. So each particular study material is expected to have a different forgetting curve in specific circumstances. Ebbinghaus forgetting curve which skirts these issues and a lot of newer research non the less can still be considered a good general estimate and starting point for how memory fades:

The plot is exponential, which means that the initial conditions greatly influence future retention rates, ( I've used a mix of subjects/conditions for an average), But as mentioned your starting point and specific situation  can greatly influence memory strength (your exponent over time ), so under bad learning conditions, no interest on the subject and a very hard to discern subject matter, your curve would look like this:

I am leaving aside flashbulb memories (aliens landed during your study session !, good luck thinking about anything but aliens for the next 3 weeks!), which are a separate topic and do not seem to obey normal memory consolidation rules.

How much time does our brain take to forget things?

As mentioned the initial conditions are critical and influence the process, there is a period of consolidation (more variables) which further influences consolidation and then one of relative stability, this period in a general simplified way looks this:

So you get a nice long sub exponential tail thanks to long term consolidation.
Just a quick note before wrapping up, in general people are overconfident, specially at the high end when it comes to memory retrieval 3.3.

how much time it should take for me to gain the same amount of confidence about that chapter as I had a couple of weeks ago?

Due to all the above variables, it is hard to give you a definitive answer, beyond the obvious one that 2-3 weeks under your initial learning conditions are inadequate and you will have to relearn (albeit you will be doing it a slightly faster rate), there are a number of strategies for sequential learning that pair our basic understanding of memory into a studying regime, here is one such strategy:

This is an oversimplification, in order for you to answer your own question, you need to standardize your learning environment and subject matter in as much as possible (don't forget to adjust for overconfidence), come up with your own decay rate and then plan your studying regime based on your learning curves which would need to be updated as you relearn and specialize, sounds like a lot, but it's basically jotting down a couple of numbers and perhaps the hardest part making sure you have the correct learning environment.
Finally, I haven't talked about learning aids, the effect of mnemonics as well as other strategies is well researched and I believe can be beneficial to anybody,specifically students, but I believe it should be used as a sort of extra boost rather than a foundation for learning. (i.e. An understanding of the material should come first) Use at your own risk.6

Notes, reference & sources:
The overarching note is that memory research stands in stark contrast to most academic programs and learning environments, practices and popular myths.
1. Neuroscience (Purves)
2. The Secret World of Sleep (Lewis).
3. The Oxford Handbook of Memory(Tulving,Craik) 3.2 Strictly speaking there are a number of other variables that influence memory stability, a high emotional context for instance seems to solidify them earlier. 3.3 Not trivial either and something like 20% of errors can be observed in high confidence reporting.
4. You still have the benefit of the priming effect and other temporal benefits, so it's not all wasted, you can catch up faster.
5. What is sometimes called Spontaneous recovery.
6. Your Memory: How it works and how to improve it (Higbee) has a lot of useful advice aimed mostly at students.


How to handle single trial ERP (P300) I am learning to work with EEG data in young and elderly subjects. The goal is to find differences in P300 (amplitude & latency) between both age groups during learning. I analyzed the data based on Grand Averages of both groups. As a confirmatory analysis I've tried to find the P300 peak for each subject individually and I performed analysis based on this peaks. Now I am interested in the variability in P300 latency in each trial, especially in elderly subjects, as the decreased P300 amplitude might be partially explained by averaging of more variable peaks. The single trial data looks very noisy and based on the fixed time window for searching P300 peaks, I am getting very different latencies for each trial. The topographies of single trial data also does not help - some looks ok, but others are just noise. Does someone know, how to handle P300 in single trial EEG data? Are classification methods for BCI going to work for this project?

I remember trying using single-epoch measurements with electroretinogram (ERG) recordings. Basically, ERG responses are electrical potential recordings from the neural activity in the retina. ERGs are usually also obtained using ensemble averages.
The single-sweep ERG amplitude measures were, as expected, also really messy due to random noise and eye movement artifacts that are normally averaged out when using ensemble averages. However, when using all 250 available individual epochs I had at the time, I could still show that ERG amplitudes slowly declined along the duration of the recording. So I took advantage of all available recordings by plotting all available amplitudes against time and performing linear regression. Linear regression is a particularly robust statistical method when a lot of data is available.
In your case, where you basically wish to do an analysis of variance on  populations of people, I would try to pool all the data available per subject and determine the standard deviation, or a related variance parameter. Then doing that for all 20 normal subjects will yield a collection of variabilities. This could then be compared to the older population. I can't advice you on the most appropriate statistical test unfortunately, but for a starters you can simply plot the 2 point clouds and compare them visually. If it looks promising, you can do a t-test (which is likely not the most appropriate test, but it will give you a fair indication). If it all looks promising, you have to find a proper analysis of variance to compare the two.


In SDT, how is an increase in detection sensitivity conceptualised in terms of the movement of the distributions? Is it conceptualised as the signal distribution moving rightward, or as the noise distribution moving leftward?

Technically it can go either way, and both situations would be conceptually and statistically equivalent. But it is conventional to fix the mean of the noise distribution at 0, so that increased discriminability corresponds graphically with the signal+noise distribution moving rightward along the latent axis.


What paper discussed the cognitive properties of Likert/visual analogue scales in ratings? I seem to recall a recent paper investigating whether ratings created using Likert or Visual Analogue Scales formats had the cognitive properties of interval or ratio data (since they are generally analysed as such).

I think a central question was whether, for example, participants understood the difference between a 2 and a 3 to be the same as the difference between 5 and 6, but I can't find it!  Does this ring bells for anybody?

I did eventually find something which may be what I was thinking of, examining the normality & psychometric properties of Likert scales with differing numbers of points.  They concluded that the 11-point scale was closest to interval-type data in scaling and normality.

Reference:
A comparison of psychometric properties and normality in 4-, 5-, 6-, and 11-point Likert scales. Leung, Shing-On. Journal of Social Service Research37.4 (Jul 2011): 412-421. http://dx.doi.org.ezproxy.library.tufts.edu/10.1080/01488376.2011.580697


What role do circular network structures play in neural networks? I'm developing small virtual neural networks and for the most part, the networks have remained feed-forward. When I create circular structures, it becomes a challenge to find a balance with the neural refactory period, stopping neurons from firing again for a period of time, giving them high action potential thresholds, then reducing that back down to fire again -it's tough to find a balance that stops infinite feedback loops but allows circular structures to play a role in processing.

I've done some reading on this and my vague idea so far is that circular structures perhaps allow the network to react to information based on its pattern, react to the information over time, so the C in an input series of A, B, C can be handled differently than the C in input series A, A, C.

Is that accurate, basically? What's the role of circular connection structures in a  neural network? I'm asking not only about multi-neuron circular structures like N1 => N2 => N3 => N1 but also about neurons that connect to themselves (N1 => N1) (which from my reading is something that happens if I understand correctly, but I'm unsure whether it achieves a similar affect as a larger scale circular structure).

 (=> represents a neural connection)

In contrast to artificial neural networks, which are almost all feed-forward architectures, networks in biological brains are highly recurrent. In the networks of cortex, the majority of synaptic inputs a neuron receives come from nearby neurons in the same area of cortex (Binzegger et al. 2004). These are the "circular" connections that you are referring to.

So recurrent connectivity is the rule, and simple feed-forward (or feed-back) projections between cohorts are the exception. The networks that result are therefore highly dynamic, and respond in complex ways to inputs changing over time. In general there is no one "reason" why recurrent connections exist. But there are guidelines about how connections between excitatory and inhibitory neurons are made.

The patterns of connections which define a network determine the computational properties of that network. At a first level, the strength and connectivity between excitatory and inhibitory neurons control the overall stability of the network (e.g. Wilson & Cowan 1973; Tsodyks et al. 1997). It's certainly possible to have self-connections and high recurrence, and still keep the network stable.

Secondly, changing the rules by which neurons connect to each other (Ko et al. 2011; Cossell et al. 2015; Lee et al. 2016; Wilson et al. 2017) changes the computational properties of the resulting network (Muir & Mrsic-Flogel 2015).

In general, biological neural networks are highly recurrent dynamical systems which bear only passing relationship to the acyclic networks that we use to think about feed-forward and feed-back connections in the brain.


Why aren't any advancements being made in physically diagnosing Bipolar and other psychiatric disorders? I was involved in a discussion where somebody had asked if others had thoughts of doing risky things during their manic episodes. Two people commented, including myself. I worried that only relying on a specific set of guidelines established by the diagnostic and Statistical Manual on Mental Disorders fifth edition could lead to disastrous consequences.

Let's say somebody came into a psychiatrist's office. The person has previously read the DSMV and understands the criteria. That person played their cards right to convince the psychiatrist to diagnose them with Bipolar Disorder, when in truth that person might not likely have it at all. Instead, their true motive would have been to get free benzos so they could space out and get high.

On the other end of the spectrum, some people have been misdiagnosed, leading to unwanted and unnecessary medications.

For both of these situations, why can't blood tests and other physical and objective means be used to insure that neither party is in doubt? You can't lie on a blood test or magneto encephalogram, so why not this?

Short Answer

Science is hard, brains are complicated, and the premises of your question that there is not work being done or advancements in this area is false.

Longer Answer

There is no known specific cause of bipolar disorder (as for many other psychological disorders). There is no simple statement like "bipolar disorder happens when you are low on XYZ so let's test for XYZ." Bipolar disorder and many others are in fact defined by the DSM based on symptoms - diagnosing them in another way is not the gold standard.

That said, you seem to be implying especially in your comment "why isn't one being developed" that this isn't an active area of research. It is - a helpful search term for you will be 'biomarker'; Google Scholar returns 4,480 results since 2017 for ("bipolar disorder" "biomarker").

However, all of the suggested biomarkers are some combination of A) Not specific (i.e., are positive for other conditions), B) Not sensitive (i.e., are negative for people that do have bipolar disorder), C) Expensive or invasive (i.e., not really worth doing if they have issues with A and B), or highly dependent on other individual factors.


Fit a psychometric function when the maximum is not 100% (not because of lapse) I found that currently the form of psychometric function assumes that the proportion correct lies between 0.5-1 given the range of stimulus level, but how to fit a psychometric function when the subject's performance never goes to 1 (and it is not because of lapse)?

An example of how this situation can happen: suppose I want to study how stimulus presentation time affect a small target's visibility in a given peripheral visual field location by a 2AFC task. The target's feature is fixed throughout the experiment. I can imagine that with longer stimulus presentation time (like 1 ms vs. 200 ms), subject can make more correct responses, but because of the limit of peripheral vision, the correct response rate can never go to 100% even if you present the stimulus for a very long time. How can I fit a psychometric function (proportion correct ~ stimulus presentation time) to data like this?

Yes. When you fit your psychometric function you try to maximize $p(X|\theta)$, with $X$ your observations and $\theta$ your parameters. When you assume 100% correct answers, you would typically assume that your psychometric function is $\Phi(s|\theta)$, $s$ being your stimulus value and $\Phi$ being a cumulative normal. More specifically $\Phi(s|\theta)=\frac{1}{\sigma\sqrt{2\pi}} e^{-\frac{(s-\mu)^2}{2\sigma^2}}$. Here $\theta$ is both the mean $\mu$ and the std $\sigma$. To have a psychometric function that does not go to 100% correct, you just need to add a third variable to $\theta$. It doesn't matter whether the observer's performance is limited by lapses or another factor, mathematically that's equivalent. Then you fit your data with $\Phi'(s|\theta)=\frac{\lambda}{2}+(1-\lambda)\Phi(s|\theta)$. With $\lambda$ your lapse rate, assuming this lapse rate is symmetrical. You could add a 4th parameter if you have a good reason to assume the lapse rate is different near 0 and near 1 (then $\theta=(\mu,\sigma,\lambda_{low},\lambda_{high})$). Also, you might run into issues because if you fit with $\lambda$ unconstrained, you could get values higher than 1 or lower than 0. So when fitting it is helpful either to use a constrained algorithm (e.g. a quasi-Newtonian gradient descent, in Matlab that would be fmincon), or better to transform your parameter using a function that is bounded like the cumulative normal function itself. In other words, use $\Phi'(s|\theta)=(\frac{\Phi(\lambda_{low})}{2})+(1-\frac{\Phi(\lambda_{high})}{2})\Phi(s|\theta)$.

It is in facts recommended to always allow for a lapse rate, as you could misestimate the slope of your psychometric function when you do not.


Performance of children at school in the morning Our local council are changing the school day to 9:30 - 15:00 for my youngest son, my eldest in a different school starts at 8:20 and finishes at 15:20.

I believe that children are more productive in the morning but do not have any specific research to confirm this.

A caveat: "productivity" is not a term used much by cognitive science, so I'll talk about cognition instead.  It's not necessarily the same thing, but it's more of an answered question.

And as a general issue: any time a question has "more" in it, the real question is "more than what?"  More productive early in the morning than later in the morning?  More productive in the morning than the afternoon?  More productive in the morning than adults?

There is little work comparing children's cognition across the daily cycle; a good review of mostly adult work can be found here (Chronobiology International (2000), 17(6), 719–732, doi/abs/10.1081/CBI-100102108).  Non-experimentally, there is some research supporting the idea that starting school later in the morning--particularly for adolescents--improves performance.

This blog post details an analysis of test scores from Wake County North Carolina (where start times vary), and shows "delaying school start times by one hour, from roughly 7:30 to 8:30, increases standardized test scores by at least 2 percentile points in math and 1 percentile point in reading. The effect is largest for students with below-average test scores, suggesting that later start times would narrow gaps in student achievement."  Obviously, there could be major confounds here: we don't know if start times correlate with performance-relevant but unmeasured characteristics--although the author seems to have done a reasonable job of controlling for measured characteristics, and compares students that are similar at similar schools with different start times.

This New York Times article cites several cases where attendance and performance rose after pushing back start times from 7.30 to 8.40, but again, the lack of a controlled comparison means that there's no particular reason to think that generalizations from this case are valid.

There are problems with this approach, of course--for starters, there's no way to control for the effect sleep duration or quality, which might be expected to covary with start time, on performance.


What is the relationship between anger management difficulties and ADHD? According to Wikipedia, "Difficulties managing anger are more common in children with ADHD"

Is it that the anger is due to ADHD specifically? Is the anger suggestive of a comorbid disorder? Could it be either?

Attention Deficit Hyperactivity Disorder (ADHD) is a type of Neuro-developmental condition whose signs can be seen during early childhood.

ADHD is related to hyperactive behavior, attention difficulties or difficulty in controlling behavior. ADHD can affect an individual’s ability, whether at school or work depending on the symptoms.

Usually, the majority of individuals with ADHD tend to have problems with aggression and emotional control.

Anger outbursts individuals with ADHD are often excessive and explosive. Some individuals may hyperfocus on their anger and frightened when they lose control and have difficulty understanding their outbursts.

ADHD is strongly associated with Oppositional Defiant Disorder (ODD) and can interfere with the successful treatment of ADHD.

I am a teacher at Accel Centre, and there are a few students suffering from hyperactive behavior while in the class.

This happens because many children and teenagers are unaware of being overly angry or otherwise they are unable to identify the origin of their anger.

On the flip side, many people with ADHD seem to only be able to focus their attention on something they enjoy doing.

References:

http://www.childhealing.com/articles/adhd.php

https://www.myvmc.com/diseases/attention-deficit-hyperactivity-disorder-in-adults-adult-adhd/


Why do people get "too old to learn"? This may be a stereotype, but many of us encounter a lot of people who insist that they can't learn a new technology because they're too old. Some of these people can be brilliant learners in their youth - doctors, lawyers, prominent businessmen, academics. It's so common that one benchmark of good web design is whether the 'average grandma' can use it.

A part of this might be from the formation of habits - someone who's used to reading the newspaper for 50 years would have trouble replacing that with online news. Another possibility is that they may feel that they have limited years to live and don't want to spend their limited time learning a new skill, or that they would have a poor ROI on these skills.

But do they actually have more difficulty learning from a physical perspective or is it just psychological?

Firstly, the matter of lifestyle is probably a significant factor.  Someone who is an alcoholic their whole life and never tries or learns new things is going to have a different outcome that somebody who is still learning new things and exercising and eating healthy.

That being said, lifestyles equal, there's at least two factors in age-associated reduction in memory and learning.  Firstly, just like hips and shoulders start falling apart, so does the brain (characterized by morphological abnormalities and synapse loss).  Organisms are very complex machines and lots of the equipment is gradually failing throughout our life.  Dementia is a typical result of age-induced wear and tear on the brain.

The other is reduced plasticity.  We start off with a very plastic brain, which allows us to learn our environment.  However, part of the process of learning is to stabilize our learning circuits so that they can't be changed again (i.e. you want memories to stay as robust as possible).  Our whole brain goes through series of this stabilization.  At 4-5 years, pruning removes "unused circuitry", greatly reducing plasticity.  In the early 20's, our frontal lobes finalize and myelinate (and this is thought by some to pertain to why people start practicing better judgment at this point).


How, other than pharmacotherapy, can those diagnosed with thought disorders be treated? In general, major depressive disorder is treated with pharmacotherapy, and talk therapy, as well as other little things written below:

People know what the little things you can do if you're depressed are:

exercise often
make sure your eating is sufficient/not excessive
make sure your sleep is sufficient/not excessive
don't engage in "depressive" behaviors such as isolation, rumination etc.
get involved more socially
separate yourself from stressful situations

But, I can't think of any of the little things associated with thought disorders, like schizophrenia...

For some reason the only thing I can think of is Cognitive Remedial Therapy...

What are the corresponding little things that are the counterpart of the list shown above for thought disorders?

Dialectical Behavior Therapy (DBT) is a unique skills training that consists of four modules: core mindfulness, distress tolerance, emotion regulation, and interpersonal effectiveness.  Originally, this set of therapeutic skills were developed as treatment for the extremely unmanageable Borderline Personality Disorder.  However, after immense success, the treatment group expanded vastly.

The modules were carefully and specifically designed to help individuals manage their behaviors, emotions, and thoughts. Each module includes a number of 'little things' intended to assist the afflicted in their area of need.

For example, the core mindfulness module teaches individuals to (with practice) slow their thoughts, bring themselves into the present moment, how to regain control of their thoughts by training the mind to focus on only one thing--on the one moment.  This particular training is typically introduced in the form of deep breathing exercises where the focus of the exercise is to think of only the breath entering and leaving the lungs/body.

The other modules offer similar skillful training techniques specific to both the individual as well as the given module.  I imagine that you will find the answers you seek by delving into the curriculum, techniques, and purposes that lay just beneath the surface of the DBT modules.


Can One Have a Temporary Manifestation of Dyslexia? I have a friend who said he was taking a test in college that involved many calculations (similar to a math test). He inexplicable mixed up numbers, for example, he switched 16 to be 61. Although he did all of the steps correctly, he got the wrong answers due to this mixup. This did not just happen once on this test, but repeatedly. He says that he has not had any issues with dyslexia throughout his life. But his sister does have it.

What might be going on here? Is it possible that he has a very mild form of dyslexia that does not manifest itself except in certain circumstances (I don't know, but perhaps he was nervous/anxious when taking the test)?

The jury is still out on temporary dyslexia, but apparently astronauts can experience it on a temporary basis on return to earth.

However, mixing up (anagramming) digits or letters is not dyslexia. And this is confirmed from another source:

  A common myth closely associates dyslexia with mirror writing and reading letters or words backwards.

At least when done with letters/words, e.g. reading smile as slime, this type of anagramming error is (sometimes) called a "migration error" (or more elaborately, transposition of letters within words). Furthermore, doing this on a regular basis is called Letter position dyslexia (LPD), a peripheral dyslexia. Some people with dyslexia also exhibit LPD, but LPD alone is not widely reported, no doubt in part because LPD is not that well studied: the first study of the developmental form appeared in 2007, while the first study of the acquired form came out in 2001, as far as I can tell. The only known cases of acquired LPD are following brain damage.

People with developmental LPD (but not full dyslexia) fail to be identified as such in standard tests of reading in English because typical reading tests don't have enough "migratable" words, c.f. a 2012 paper that was the first to look at LPD in English (with just 3 cases though). Also of note, one of the three cases discussed there was also officially diagnosed with attention deficit disorder and another one was suspected.

One interesting aspect is that LPD is not caused by swapping phonemes; for instance someone with LPD can read cloud instead of could (even though there's no ell heard in could). Based on this it seems plausible to me it could affect number reading as well, but I haven't found any published research on migrating digits in numbers. A 2nd (2014) study of LPD in English included a verbal digit span test, but the LPD children did not have any problems with this test; they were actually above average on verbal digit span. The paper does not report any number reading tests, unfortunately.


How do we explain that some humans require far more evidence for some claims than others? Tell people that God says something and they believe.

Tell people that the paint is wet and they have to touch to believe.

If I ask people if God really made http://thegoodlordabove.com/god-talks-several-trump-supporters-need-safe-space/ people would laugh at me.

If I ask people if God really made the bible or send prophets, many will stone me for even asking their sacred beliefs.

Why?

Is fear of authority or instincts to obey the authority, or lack of personal cost of being false makes people easily believe things?

The bible and quran, for example, carries tons of authority and tend to support status quo. People would at least have incentive to pretend they believe. A wet paint doesn't. Or what?

What are the explanations?

There are at least two important factors or phenomena at play here. The first is whether the subject of the belief has real-world consequences to the believer. The second is whether the belief relates to groups to which the believer associates or belongs.

When a person's belief on a particular matter makes no functional difference to that person, he or she is free to believe whichever or whatever way without gain or loss. In this sense, it is easy for a person to criticise others for doing something a certain way when the person doing the criticism is not in the business of trying to accomplish the same goal. A person might complain, for example, that company X would be more successful if they focused on product Y instead of product Z. Having this belief is inconsequential to the believer since he or she has nothing to gain or lose from being right or wrong. A similar occurrence is when a person believes something to be dangerous without real evidence, as for example the consumption of GMO foods. Whether GMOs actually hurt you is irrelevant to a person who eats strictly non-GMO organic foods. Granted the person has no shortage of money, the accuracy of this belief makes no functional difference, so there is little if any incentive to be honest about the actual safety record. For a person having barely enough money to buy food, on the other hand, the actual safety record of low-cost foods is much more pertinent and important since the decision makes a substantial difference in financial burden. It is easy for a person having ample money to make the claim that expensive items are substantially safer and more effective. For a person with limited funds, the truth of the matter is far more important.

In the case of wet paint, if there is a risk to the person of getting the paint on his or her clothes, then the person is likely to see real consequences in the reality of the matter. Hence, there is little room for carelessly choosing a belief -- the truth has real consequences to this person.

A person's affiliations and group identity may be given high priority, especially when a person stands to gain from that association. Any attack or perceived attack on the group or its collective beliefs may be taken as an attack on the individual. The group may be seen and felt as an extended self. A person having no such association or feeling toward a group or its beliefs is not likely to be much offended or protective of those beliefs. Hence, he or she is free to consider their truth or falsehood. Someone whose life and well-being depend on that group or set of beliefs, on the other hand, is not going to take skepticism lightly since it poses a very real threat. In this sense, the situation is similar to that mentioned above about consequences. If a person depends on a group or belief-system for material or emotional well-being, then any attacks on that group's reputation or status may harm the person indirectly.

Naturally there is a third factor where certain religions impose or threaten penalties for those who do not defend the religion and its beliefs. In this case, a true believer may protect the group and its beliefs purely out of fear for said consequences.

To answer your main question more directly, those for whom knowing the truth is more consequential will require greater evidence than those for whom knowing the truth is irrelevant or even harmful (whether materially or emotionally). A person dependent on a group for material or emotional support is more likely to believe in that group and its teachings, regardless of the truth.

On a side note, even science can be seen as a group identity these days, from which we can expect that some individuals would derive emotional or material well-being. Having an emotional stake in science would make a person require more evidence to the contrary before considering a religious perspective. Unfortunately, this type of group identity can blind individuals on both sides of the science/religion debate, among other debates (politics, GMOs, et cetera). Ego and emotion, when left unchecked, can be very harmful.


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.

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


Is depression caused by life events? If we look at physical illnesses we could put them on a spectrum of 'Happened spontaneously/no choice in the matter' to 'Was clearly created by something that happened in their life'.

From less causal, to more causal I'd suggest a list like this.

Genetic disorders.   (Entirely genetic, from birth)
Down syndrome. (Genetic, but age of parents plays a part)
Cancers that happen 'randomly' (eg. breast cancer).  (Random, but some people have genetic disposition)
Common cold. (Not sure where to put this on the spectrum, but caused by a cold, but some people are more susceptible than others).
Obesity. (Some people have a higher disposition to obesity)
Smoking related illnesses. (Caused by smoking, but some people more susceptible than others).
HIV.  (Caused by a virus transferred by contaminated blood/unprotected sex)
A broken leg. (Caused by physical trauma)

That is - the illnesses at the top of the spectrum have some kind of genetic cause, or we don't know enough about them to say how/why they occur, whereas the illnesses at the bottom of the spectrum are clearly caused by some life event.

With a mental illness like schizophrenia - it seems clear that this would fit at the top end of the spectrum - the schizophrenic was schizophrenic from birth, and there was nothing that 'caused it'.

However, it seems that depression is often the result of life events - stress, addiction, pregnancy, grief etc.

Is this a valid way of looking at depression? What terminology and research is there about it?

Both schizofrenia and depression are linked to a genetic predisposition and life events. Individuals with no genetic predisposition may become depressed when the trigger is sufficiently intense, while individuals with genetic predisposition may become depressed in the absence of clear life events triggering the depression (Kendler et al, 1995).

Reference
- Kendler et al, Am J Psychiatry (1995); 152(6): 833-42


Effect of words highlighting on reading comprehension I'm interested if there are studies dealing with text understanding and POS (part of speech) coloring, or coloring syntactic/semantic information. The studies should solve the questions like:

Which combination of colors improve/deteriorate understanding and reading of texts?
How many colors should be in the scheme for positive/negative effects on reading and understanding of text? Which POSs should be preferably colored?
Are there types of people who are more efficient with/without coloring?

I believe that a few colors with good combination could be beneficial. Has somebody conducted research to test the effect of highlighting on reading comprehension?

An example:

On this text you can see that many colors that don't go together can make the reading process even worse and distracting. Can this be changed to improve the reading process, instead?

A few events inspired me in the following order:

I started learning Chinese and their characters seem to have positive effect on my comprehension.
I've read a NL (natural language) article in English in a programming editor. I was used to colors for various programming languages.
I searched the Internet and found the article A case against syntax highlighting but don't agree with all the author's arguments or opinions. When you have only a few carefully chosen colors it's beneficial for programming so maybe could be for NL comprehension as well. A few colors could underline the basic thought and help to draw attention of the reader. When I read a scientific text for which I have not passion I'm often bored because don't know where it directs and colors and images help me a lot to concentrate and skimming over the basic thoughts could help with decision if it has sense to read it at all. This does not hold for fiction and poetry where we read for pleasure rather than getting information.

I can speak to this question somewhat from a cognitive psychology standpoint. We memory researchers would think of text highlighting like this in terms of distinctiveness. (An article by McDaniel and Bugg (2008) may shed some light.) Simply put, highlighting a word in a different color than the rest of the text draws what we call item-specific processing towards that word. You'll have a better memory for it, for sure -- and maybe this ties into goals more relevant when writing code.

Increasing item-specific processing, however, comes with a cost: It detracts from organizational processing, which is involved with interrelating sentence (or code) elements, memory for order, and so forth.

Also note that the more items that are made distinctive, the less of a benefit making an additional item distinctive provides (e.g., if words are multicolored already, making a new word red or green doesn't really do anything to the distinctiveness of that word).

So when you use a lot of different highlighting colors, like in the example image, two things are happening: (1) too much distinctiveness is being used, washing out benefits from distinctiveness; and (2) increasing item-specific processing for individual items damages memory and processing for the structure. In essence, the example given is the worst of both worlds.

To answer your question, it might make sense to only use highlighting (or colors, fonts, etc.) to highlight key points, etc.; much like what we already do in writing for the web. Like anyone who highlights a textbook knows, it doesn't do any good to highlight an entire chapter.


Questionnaire that measures participants emotion at the time of completion of the questionnaire Could anyone help with finding a questionnaire that measures participants emotion at the time of completion of the questionnaire about the effect on memory recall in eyewitness testimony?

Your question is very specific in that it pertains to memory recall in eyewitness testimony. But presumably the context is not the main point. The main point is that you want to get a measures of state emotion.

The most common measure that I'm familiar with is the PANAS (Watson, Clark, Tellegen, 1988). It asks about the frequency of experiencing a set of common positive and negative emotions. It yields overall scores positive affect and negative affect. It can be asked with different time-frame instructions (e.g., last hour, today, last week, etc.). Choose the time frame that most aligns with your construct of interest.

See also

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

Watson, D.; Clark, L. A.; Tellegen, A. (1988). "Development and Validation of Brief Measures of Positive and Negative Affect: The PANAS Scales". Journal of Personality and Social Psychology. 54 (6): 1063–1070. doi:10.1037/0022-3514.54.6.1063.


Are mentally ill people more violent? A lot of people are afraid of people with mental illnesses because they think they're more violent but is that true?

I think it's wrong even though I don't really understand the pages I found on google. I found this article from University of Washington which states among other things that "the vast majority of people with mental illness are not violent". I understand this article but it is really short.

'Mental Illness' covers such a broad range of illnesses that it would be very difficult to answer your question. However, general consensus is  that: people who are receiving an effective treatment for a mental illness are no more violent or dangerous than neurotypical/ 'healthy' people. People with a mental illness are more likely to harm themselves or to be harmed. There is a weak association between violence and mental illness, especially when alcohol or drug misuse is involved. Early treatment of mental illness is the key to preventing violence. This article covers the topic fairly thoroughly:

Link, B. G., & Stueve, A. (1995). Evidence bearing on mental illness as a possible cause of violent behavior. Epidemiologic Reviews, 17(1), 172-181.

This is from their conclusion on mental illness and public safety:

  People with mental illness pose no greater threat to public safety than do such other "high risk" groups as men or young adults or people with less than a high school education.


Is there a psychological explanation for people being 'overcome by the Holy Spirit'? I am a scientist by nature, and I don't believe at all in God or any form of spirituality or the Holy Spirit (of course).

However, it does confuse me as to how some people genuinely do seem to be overcome by 'spirit' in certain more extreme churches.

http://www.youtube.com/watch?v=BuOBdGeArZw Watch this clip, and at about 3:35 the man goes into a strange state, and states like this do happen.
As well as this, my dad once began crying for no reason in a Church or Mosque or something at the altar.

Are there any scientifically/theoretical psychological explanations as to why this could be possible without the need for any sort of spirituality?

Research in this area is pretty patchy. Summarizing what Wikipedia says on the topic:

"God helmet" experiments were plagued by failures to reproduce by independent research groups
TLE (temporal lobe epilepsy) and its effect known as Geschwind syndrome is one plausible cause... but that does not explain it in all people
hippocampal atrophy is a more recent hypothesis, although it seems backed by only one study insofar

Independently of Wikipedia I found:

a study by Urgesi et at. (2010) on the effect of brain lesions (following brain cancer removal) on self-transcendence, which determined that "self-transcendence increases after damage to lt and rt inferior parietal cortex".
a 2009 study by Inzlicht et al. found that "religious conviction is marked by reduced reactivity in the
anterior cingulate cortex (ACC), a cortical system that is
involved in the experience of anxiety and is important for
self-regulation [...] These correlations remained strong even after we controlled for personality and cognitive ability." And the paper goes as far as having a "xanax of the people" heading for one its sections, and obvious pun on the better known phrase of Marx. The authors also point out that a similar anxiolytic effect was observed in studies of other strong beliefs, but not necessarily religious, e.g. ideological/political, citing Amodio et al. 2007 and Kay et al. 2008. (And starting to digress here, but the Amodio study has elicited strong reactions in the press).


What is the difference between personality disorder and other types of mental illness? From Personality disorders - Mayo Clinic:

  A personality disorder is a type of mental disorder in which you have a rigid and unhealthy pattern of thinking, functioning and behaving. A person with a personality disorder has trouble perceiving and relating to situations and people. This causes significant problems and limitations in relationships, social activities, work and school.

From Mental illness - Mayo Clinic:

  Mental illness, also called mental health disorders, refers to a wide range of mental health conditions — disorders that affect your mood, thinking and behavior. Examples of mental illness include depression, anxiety disorders, schizophrenia, eating disorders and addictive behaviors.

So I understand the personality disorders are more about having a rigid and unhealthy pattern of thinking, while mental illness in general is more about mood. However, in my understanding that mood is just automatic thinking that stems from past experience, which is no differ than personality disorder. The CBT approach, which is again fixing incorrect automatic thoughts, seems to be successful in working with both of them.

So is there any actual difference between them? Or is that personality disorder just an extreme version of mental illness, in which the belief is more systematic (world view or belief system I would say)?

A minor and quick to answer question: why is personality disorder has the "personality" in its name?

There may not be one:

  it is impossible to conclude with confidence that personality disorders are, or are not, mental illnesses; there are ambiguities in the definitions and basic information about personality disorders is lacking.

https://www.ncbi.nlm.nih.gov/pubmed/11823318/

Mental illness in general isn’t about mood, either. Mood only covers mood disorders, but the DSM and ICD contain other conditions too: autism, schizophrenia, etc.

Mental illnesses also have biological components, they’re not solely disorders of thought patterns formed over time.


How are humans able to read scrambled text/characters (e.g., CAPTCHA)? So I'm doing a research on developing a new text-based CAPTCHA system. I've devised a scheme where characters in a text are broken/split individually and randomly, making it difficult for OCR machines to decode it. (See figure for example) This CAPTCHA is still under development, but it gives a rough idea of what I'm talking here.

My main aim here is to understand how the brain reads scrambled characters, as shown in the figure. I was looking up and a term called "filling-in" phenomena of vision came up. I'm not sure if that term is right in this context.

I want to know the terminology and basic understanding of how humans are able to read scrambled text/characters easily.

A human brain recognises letters by their constituent features (sub-letter parts). It is modelized by a pandemonium model where printed information is extracted locally then globally. In the letter recognition literature, this type of feature-based hierarchical model competes with template matching theories (with an advantage to the pandemonium-like models such as deep-learning networks).

Scrambled characters are recognised the same way, with the difference that only part of the visual information is available. It relates to the theory of geons developed by Biedermann (Recognition by components, 1987). He wrote

  if an arrangement of two or three sub-components can be recovered from
  the input, objects can be quickly recognized even when they are
  occluded or extensively degraded.

Could you identify the following object? Left is the unrecoverable version.

REF:

Grainger et al (2008). Letter perception: from pixels to pandemonium. Trends in Cognitive Science.
Biederman, Psychological Review (1987) & http://en.wikipedia.org/wiki/Recognition-by-components_theory


Reduction of the hippocampus due to childhood neglect/abuse A Scientific American article, "Childhood Stress Decreases Size of Brain Regions", by Christie Nicholson briefly mentions the implications of childhood neglect and abuse on brain structures. I was interested in the reduction of the hippocampus. Are there any studies that explain the reasoning behind this reduction?

Could the reduction be a coping mechanism in reducing the probability of remembering extremely negative memories (ex. physical abuse)?

In many studies scientists claim that the early exposure to stress can cause a hippocampal remodeling (or atrophy) (Andersen & Teicher, 2004). The atrophy is a disbalance in the brainpart were one part is bigger than the other. The decreased hippocampus is also associated with a decrease in dendritic branching and neurogenesis. Neurogenesis is the development and growth of neurons (in short) and these neurons are important for functioning.

In a study done by Teichera et al. (2003) they come with two explanations for the reduced volume of the hippocampus. One explanation is that the reduced hippocampus volume is associated with adolescence alcohol abuse due to the child abuse. The other explanation they have is that it is not the childhood abuse causing the reduced volume, but a risk factor for the persistence of Post Traumatic Stress Disorder in adulthood. So they are already born with a slightly decreased hippocampus volume, but this gets more when child abuse is involved.

Andersen, S. L. & Teicher, M. H. (2004). Delayed Effects of Early Stress on Hippocampal Development. Neuropsychopharmacology 29,1988–1993
Teichera, M. H., Andersena, S. L., Polcarib, A., Andersona, C. M., Navaltaa, C. P. & Kim, D. K. (2003). The neurobiological consequences of early stress and childhood
maltreatment. Neuroscience and Biobehavioral Reviews 27, 33-44


Why do many parents prevent children from being exposed to anything sex-related? We remove children from anything that is sex related, including talks and photos. When I think about it, it seems deeply and morally wrong to not do it.

When I first thought about that, I thought that it might be because we don't want to encourage them to become sexual. But we also don't want them to be violent, and no one thinks it's wrong to send a 5 year old to a martial arts class. For any other aspect of life, we let them, to some degree, experience.

That made me think that it might be something more than cultural.  Of course the definition of "child" may vary depending on the society,  but not the moral code of that ruling.

If I were to guess, the reason is probably something to the effect of: because children would not understand since they lack the same (or same level of) sexual urges that adults have. Another thought that comes to mind is maybe parents are afraid (or even ashamed) of their children seeing them (the parents) acting essentially like non-human animals. Sexual intercourse activities are usually very animalistic compared to most of the things we do in everyday life of modern society. For a similar reason, many parents probably would not want their kids seeing the parents drunk or otherwise acting uncivilised. In a way, it is like the parents are trying to hide from the kids the fact that adults are in many ways just big babies who are good at hiding it. The idea that humans are supposed to be civilised and clean is somewhat unnatural, yet common culture seems to view this idea as highly important.

On the topic of war and violence, my guess as to why these are often considered okay for children to see is because awareness of danger and the threat of violence are necessary even for a child, while knowledge of sex and sexuality really is not that essential at a young age.


Does Facebook activity predict job performance? I've seen a little bit of discussion in the media about  Facebook being used in selection and recruitment settings.
Assuming an employer can gain access to a person's Facebook profile, have any scientific studies been conducted to assess the following questions:

Does Facebook activity predict job performance?
If so, what does Facebook activity measure as seen by correlates with existing scales (e.g., personality, intelligence, integrity, etc.)?

Summary of Kluemper et al 2012

I had a read through the article by Kluemper et al (2012) mentioned in the answer by John Pick. The following summarises some key points.

After discussing the broader context of using social networks to measure personality, Kluemper et al (2012) cited the findings of a couple of existing studies:

  Karl, Peluchette, and Schlaegel (2010) found that social network users high in
  conscientiousness were less likely to post problematic content
  (e.g., substance abuse, sexual content), while Amichai-Hamburger and
  Vinitzky (2010) found a relationship between self-rated extraversion
  and number of Facebook friends.

The study by Kluemper et al (2012) involved two studies. Each study involved getting ratings on around 250 participants including self-report Big 5 personality and then getting three raters to read through the participant's Facebook profile and then fill out a measure of Big 5 personality. Self-other correlations for the same personality factors ranged from .16 to .44. This supports the idea that Facebook profiles can be used to get at least an approximate measure of personality.  It should also be mentioned that these self-other correlations are a fair bit lower than those obtained by Costa and McCrae (1998) when using the NEO, and a single knowledgeable other-rater (e.g., in the r=.5 to .6 range).

Meta-analyses have generally found a positive but weak correlation between Big 5 personality and job performance (e.g., Barrick & Mount, 1991). In combination with the results from Kluemper et al, this may suggest that personality measures extracted from Facebook profiles might predict job performance. However, given the relatively low self-other correlations, this still requires further empirical testing.

Furthermore, extracting Big 5 personality using three raters reflects only one rating strategy. Thus, there are many other useful measures and measurement strategies that could be explored.

References

Amichai-Hamburger, Y. & Vinitzky, G. (2010). Social network use and
personality. Computers in Human Behavior, 26, 1289–1295.
Barrick, M. R., & Mount, M. K. (1991). The Big Five personality dimensions
and job performance: A meta-analysis. Personnel Psychology, 44, 1–
26.
Costa, P. T. & McCrae (1988, PDF). Personality in adulthood: A six-year longitudinal study of self-reports and spouse ratings on the NEO Personality Inventory. It's not a meta analysis. N = 167 for spouse ratings.
Karl, K., Peluchette, J., & Schlaegel, C. (2010). Who’s posting Facebook
faux pas? A cross-cultural examination of personality differences. Inter-
national Journal of Selection and Assessment, 18, 174–186.
Kluemper, D. H., Rosen, P. A. and Mossholder, K. W. (2012), Social Networking Websites, Personality Ratings, and the Organizational Context: More Than Meets the Eye?. Journal of Applied Social Psychology. doi: 10.1111/j.1559-1816.2011.00881.x URL


Why (and how) do people seek acknowledgement? I don't think I need to give evidence that people do seek acknowledgement; if it's not from parents, it's from lovers or friends. It can be things as big as life ambitions/achievements (e.g. 'I will support your dreams are!', to smaller things like acknowledging you understand ('I understand what you're going through').

Possible pointers:

What makes us seek acknowledgement? (evolutionarily-wired or socially-induced)
What is the process that turns this acknowledgement into a good feeling?

I've come across a lot of blogs and opinions, I am interested in seeing if there's any scientific research on this.

Freud would say its all your Mother's fault you want acknowledgement! She should have never told you thats a good job. Indeed current pseudo-scientific psychologist say our childhood programming given to us by our guardians and peers are the reason why we seek affirmation through certain means. Their thought is if your parent created an appetite in you for praise and external affirmation then you will seek such from other people.

The thought that children are addicted to parental approval may be valid however I doubt such addictions come through praise alone. I suspect that gifting and rewarding much in the way Prince Horace was spoiled in the Whipping boy or the complete inverse like Lex Luthor's relationship with his father in the Smallville DC universe or Jace Lightwood's relationship with Valentine Morgenstern in the Mortal Instruments Universe. In these cases the parent was cruel to the child demanding an unnatural level of performance. In modern and real life that would be the bad sports scholarship parent vs the good parent involved in the life thier children which includes sports.

Science on the other hand offers a more clear view our desires for affirmation come from a maldeveloped self-esteem. As individuals we should not require the praises of others to remain mentally stable and happy. However when people base their self esteem on the praises and acclamations of others. They create a system which they are not running but an external group must continue and this is counter productive.

  College students who based their self-worth on academic performance did not receive higher grades despite being highly motivated and studying more hours each week than students who did not rate academic performance as important to their self-esteem, Crocker found. Students who based their self-worth on academic outcomes also were more likely to report conflicts with professors and greater stress.

  "They feel motivated to do well in academics, but having their self-worth on the line doesn't help their performance," Crocker says. She speculates that students who base their self-worth on academic performance might become anxious and distracted and threatened by feelings of failure, and, as such, their anxiety might then interfere with their memory.
  Students who based their self-esteem on internal sources--such as being a virtuous person or adhering to moral standards--were found to receive higher grades and less likely to use alcohol and drugs or to develop eating disorders.

  "We really think that if people could adopt goals not focused on their own self-esteem but on something larger than their self--such as what they can create or contribute to others--than they would be less susceptible" to some of the negative effects of pursuing self-esteem, Crocker says. "It's about having a goal that is bigger than the self."
  Crocker's research appeared in a recent issue of the Journal of Social Issues (Vol. 58, No. 3).

-APA Self-esteem that's based on external sources has mental health consequences, study says

The follow is a valid summary of the science behind the previous series of work:

  Authentic self-esteem is not dependent upon others or things external to us. Such self-esteem is a manifestation of our relationship with our self. The essence of self-esteem is that it flows from within. If we lay ourselves bare in our vulnerability and strip away our careers, our families, our friends, our possessions and achievements, what are we left with? And how does that feel? Beyond the obvious losses, do we like and respect who we are, irrespective of the markers of other-esteem?

  We modify and mold so much of our behavior and even more, our very personality to achieve other-esteem. We literally create personality masks in this endeavor, presenting to others the person we think they would approve of. In such circumstances we are abandoning our true self to derive approval or recognition from others. Not only is this a self-deprecating experience, it also sabotages our relationships, for they are far from authentic. When we act in this manner we are literally taking our well being and serving it up to other people. It then becomes the other person's to decide if we are worthy. This is not a healthy place to be and it is a soul-defeating exercise. We should never judge ourselves based upon who we think others see us.

  Who is the Judge?

  The simple truth is that others don't judge us. They may have opinions of us. Yet, to elevate their opinion to the status of a judgment is simply ridiculous. No one can judge you unless you grant him or her the power of being your judge. Why would we put a judge's robes on an ordinary person and confer such power upon them? The only person who you might grant such power to works in a courtroom; all others are people with opinions. With a healthier measure of self-esteem we might more easily tolerate other's opinions without escalating them into counterfeit judgments.

  Esteem most be generated from within and can then radiate outward. When we focus outwardly for approval, we are seeking it in the wrong place. And in so doing, we subordinate our authentic being in a vain attempt at happiness. Such fulfillment must be dependent and superficial and undermines our personal evolution. This process of external gratification is other-esteem. Self-esteem is not contingent upon others.

  When we set up this drama around approval, we create issues in regard to notions of rejection. The issue of rejection can be misleading. With a healthy self-esteem one doesn't consider rejection. It is actually the rejecting of one's self that inclines people to seek approval from others. In such cases, we're not content with ourselves and so we solicit that acceptance from others. If that approval isn't granted, we have a habit of claiming that we were rejected. In truth, we have rejected ourselves when we set others up as judge. The degree to which we are reactive to other's opinions of us in likely inversely correlated to our level of self-esteem.

  A reconsidering of our understanding of self-esteem might be helpful in reframing our cultural expectations of happiness. Almost all parents would claim that they are thoroughly invested in their children's self-esteem. Educators and other professionals place great value on the development of children's self-worth. Yet, I would argue that most don't begin to comprehend self-esteem. If an A student becomes depressed by a B, it is abundantly clear that their grades are a product of other-esteem. As such, the diminishment of other-esteem leaves them feeling devalued. Their sense of well being is dependent upon factors outside of themselves. Similarly, athletic achievement or popularity are things that we understandably encourage in our children. When put into proper perspective we might see that these experiences might enhance their lives. But it is critical that they not be the cornerstones of how they see themselves. For in that case, the average student or the mediocre athlete is relegated to the imprisonment of low self-esteem.

  Self-esteem is the legitimate foundation for a healthy relationship with our selves and others. Genuine self-esteem removes the construct of neediness so prevalent in most relationships. And liberates us to thrive, as issues of rejection and judgment recede. If we seek our esteem from outside, we leave ourselves in a tentative and dependent place. When the sense of worth emanates from within, life unfolds in a empowered way.

-Self-Esteem or Other-Esteem?