Extras

Eye-catching studies that didn't make the final cut:

Asch experiment replicated with 6-year-old kids.

Still got it? What happens to narcissists' personalities when they get older?

Depressive realism research. Mild depression (but not moderate) linked with greater insight into one's own memory performance.

Teens who completed exercises focusing on their strengths showed boosts to their life satisfaction.

A taxonomy of kids' cries: "Screaming, yelling, whining, and crying: Categorical and intensity differences in vocal expressions of anger and sadness in children's tantrums"

Relevant to the Norwegian killer? The psychology of lone-wolf terrorism.

Seems obvious. Bored employees more likely to indulge in horseplay and other counter-productive behaviours at work.

Evidence for increased aggression in breast-feeding mothers.

No it can't. “Can It Read My Mind?” – What Do the Public and Experts Think of the Current (Mis)Uses of Neuroimaging?

Come on the Seagulls! Chanting football spectators show heightened aggression after a game, compared with non-chanters.

Emotions in music: "The results show that six basic emotions are perceivable in musical segments previously unknown to the listeners".

50 years on ... mental distress linked to the Nagasaki bomb.

--
Post written by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

Psychodynamic psychotherapy for children and adolescents: a critical review of the evidence base. [open access]

Why men and women dehumanize sexually objectified women.

"According to our findings, creative people and people suffering from mental disorders appear to share some common personality and cognitive traits"

Which is the more cooperative sex? A meta-analytic review uncovers some interesting findings, including: "Male–male interactions are more cooperative than female–female interactions (d = 0.16), yet women cooperate more than men in mixed-sex interactions (d = −0.22)."

Would you take a pill to ease your traumatic memories? Attitudes about memory dampening drugs depend on context and country.

More dead than dead: Perceptions of persons in the persistent vegetative state.

Chicks Like Consonant Music.

Beautiful babies are no more likely than average to grown into attractive adults.

Hungry like the wolf: A word-pattern analysis of the language of psychopaths.

"... men at risk of exhibiting sexually aggressive behaviour showed worse memory for women's sexual interest."

--Post compiled by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

Just in time for the latest series of X-factor: "A frog in your throat or in your ear? Searching for the causes of poor singing."

Drinking decaffeinated coffee boosts mood, vigour, attention, psychomotor speed and reward responsivity, so long as you think it's got caffeine in it.

A statistical error that's widespread in neuroscience (pdf via author website).

Memory in women is sensitive to male voice pitch.

Nostalgia provides us with existential meaning.

Does sexism motivate some of the advice offered to pregnant women?

When Prisoners Take Over the Prison: A Social Psychology of Resistance.

Obstacles, literal and metaphorical, trigger a global processing "big picture" style of thought.

Understanding workplace boredom among white collar employees.

Bisexual men really are aroused physically and subjectively by both sexes (for years past research has failed to demonstrate this).

Spoiler false alarm! People enjoy stories more when they know what's going to happen.

There's too much emphasis on individual face-to-face therapy.

Hearty, social laughter increases pain tolerance.

Male dance moves that catch a woman's eye.

Health and psychological well-being benefits of pets have yet to be proven.

At what stage do unborn babies start to perceive pain? "The results suggest that specific neural circuits necessary for discrimination between touch and nociception emerge from 35–37 weeks gestation in the human brain."

Bereaved parents more likely to die in ensuing years after loss than are non-bereaved parents.

--
Post compiled by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

The neural correlates of aesthetic appreciation: "We present here the most comprehensive analysis to date of neuroaesthetic processing ..."

Why do we take such a lenient view of white-collar criminals?

A forum on mirror neuron research.

The effect of neuroimaging and other evidence on jurors' decision making. "Overall, neuroscience-based evidence was found to be more persuasive than psychological and anecdotal family history evidence."

Littering in Context: Personal and Environmental Predictors of Littering Behavior.

Psychology at the gym: Treadmill Experience Alters Treadmill Effects on Perceived Visual Motion.

The Enigma of Number: Why Children Find the Meanings of Even Small Number Words Hard to Learn and How We Can Help Them Do Better.

Power Increases Infidelity Among Men and Women.

Synaesthetic Associations Decrease During Infancy.

Personality and gang embeddedness.

Heaven It's My Wife! Male Canaries Conceal Extra-Pair Courtships but Increase Aggressions When Their Mate Watches.

Do children really recover better? Neurobehavioural plasticity after early brain insult.

--
Post compiled by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

A longitudinal study of children's text messaging and literacy development.

First ever mapping of women's genitals as represented in the sensory cortex of the female brain. "Vaginal, clitoral, and cervical regions of activation were differentiable, consistent with innervation by different afferent nerves and different behavioral correlates. Activation of the genital sensory cortex by nipple self-stimulation was unexpected, but suggests a neurological basis for women's reports of its erotogenic quality."

Being mistreated in childhood linked with recurring, hard-to-treat depression in adulthood.

Links found between a person's spatial skills and their social acumen.

A meta-analysis of the bystander effect - the dilution of social responsibility when we're in a group. But there are also situations in which helping is increased in groups.

In a random sample of 274 U.S. married individuals, 40% of those married over 10 years reported being “Very intensely in love.”

Human intelligence is highly heritable and polygenic.

The influence of regional accents on job interview outcome.

You probably think this paper's about you: Narcissists' perceptions of their personality and reputation.

Much-needed longitudinal evidence for the contact hypothesis - the idea that intergroup contact reduces prejudice.

How teens with autism spectrum disorder spend their time.

After bad luck, people are more willing to take risks again if they've had a chance to wash their hands.

The dynamic interplay between negative and positive emotions in daily life predicts response to treatment in depression: A momentary assessment study.

Yet another dark side of chivalry: Benevolent sexism undermines and hostile sexism motivates collective action for social change.

"it is suggested that we may observe an increased neuroticism or psychopathology in society if children are hindered from partaking in age adequate risky play." (pdf)

If you like this Extras post, you might also like our new Feast feature (our round-up of the latest juicy tit-bits in psychology news), and the Special Issue Spotter (with links to the latest journal special issues in psychology).

--
[Compiled by Christian Jarrett for the BPS Research Digest.]

Extras

Eye-catching studies that didn't make the final cut:

Anomalous experiences in the general population are common.

Expert footballers may extract more information from a single glance.

Should juries be made up of fewer than twelve people?

Why don’t smart teens have sex?

Attempting to quit smoking without telling anyone is just as effective as making a public announcement.

Brain stimulation over Broca’s area differentially modulates naming skills in neurotypical adults and individuals with Asperger’s syndrome.

Agitated honeybees exhibit pessimistic cognitive biases.

Good mothers, bad thoughts: New mothers’ thoughts of intentionally harming their newborns.

A meta-analysis of interventions to reduce loneliness.

Working memory training and transfer in older adults.

Is there a sensitive period in human incest avoidance? (pdf)

The neural correlates of narcissism.

_________________________________

[This post was compiled by Christian Jarrett for the BPS Research Digest.]

Extras

Eye-catching studies that didn't make the final cut:

Slopes feel steeper when felt by foot compared with finger.

12 to 18-month old babies have an awareness of fairness.

How often do new rigorous research findings in medicine overturn the previously accepted best evidence? (Commentary from Ben Goldacre).

Gut feelings: the emerging biology of gut–brain communication.

Short- and long-term benefits of cognitive training.

Finches demonstrate grammatical ability previously considered unique to humans.

A framework for ensuring BOLD-changes (as detected with fMRI brain scanning) observed through childhood and adolescence and beyond are due to cognitive changes rather than neurovascular factors.

The reward of a good joke: neural correlates of viewing dynamic displays of stand-up comedy. (via @sarcastic_f).

Neural mechanisms of the cognitive model of depression, by Aaron Beck and others.

The benefits of pet ownership (via @psypress).

Medical school reduces trainees' levels of self-reported empathy. (Commentary from Vaughan Bell).

[This post was compiled by Christian Jarrett for the BPS Research Digest.]

Extras

Eye-catching studies that didn't make the final cut:

Our dreams lose their colour as we get older. (see earlier item on the Digest).

Infant whining is uniquely distracting, even more than machine noise (pdf).

For Fun, Love, or Money: What Drives Workaholic, Engaged, and Burned-Out Employees at Work?

Identifying uncoerced false confessions as told by real offenders: "more self-deprecations and doubts about own testimony in the told lies, and more unexpected complications in the truths."

Wishful Thinking Belief, Desire, and the Motivated Evaluation of Scientific Evidence. (see earlier item on the Digest).

Psychological Health of Orphan Bonobos and Chimpanzees in African Sanctuaries.

You may have heard of Cyberball, a computer-based passing game that's used to study the effects of ostracism (when the other players don't pass you the ball). A new study uses a variation on this theme "Cyberbomb", in which the ball can explode. Now participants don't mind being left out so much. "Results showed that such a symbolic threat to survival is able to reduce the immediate distress caused by ostracism," the researchers said.

Public skepticism of psychology: Why many people perceive the study of human behavior as unscientific.

You filthy beast! What makes animal metaphors so offensive?

Little evidence that rates of common mental disorder are rising in England.

[This post was compiled by Christian Jarrett for the BPS Research Digest.]

Extras

Eye-catching studies that didn't make the final cut:

College students aren't very accurate at judging how drunk they are.

The effects of weather on walking rates in nine cities.

"Hey Mom, What’s on Your Facebook? Comparing Facebook Disclosure and Privacy in Adolescents and Adults".

Testing yourself over time, with long gaps between tests, is beneficial to memory. But the precise schedule of when those tests occur (e.g. with expanding, contracting or equal gaps between them) doesn't matter.

For girls, but not boys, greater consistency of hand preference in infancy was related to superior cognitive outcomes from age ten to 17, for example in verbal intelligence.

People who hoard animals.

Food automatically grabs people's attention, especially if they have low BMI.

Apolipoprotein E4 is a risk factor for Alzheimer's, but does it exert a benefit on cognitive function in healthy young adults?

Even bigots show reduced prejudice after inter-group contact.

Autism may have bestowed people with a survival advantage as skilled solitary foragers (PDF).

The cognitive consequences of envy.

Autism is twice as high in Eindhoven, the IT centre of the Netherlands, than in Haarlem or Utrecht.

Diet motivation in young women is driven more by fear than by hope.

You do not talk about Fight Club if you do not notice Fight Club: Inattentional blindness for a simulated real-world assault.

[This post was compiled by Christian Jarrett for the BPS Research Digest].

Extras

Eye-catching studies that didn't make the final cut:

The science of stepping off a kerb.

Women's telephone calls last longer than men's.

What's it like to live with parents who have OCD?

Appealing to a sense of common humanity among the victims of historical atrocities increases their forgiveness of perpetrators, but there's a downside - it reduces their collective action to overcome inequalities and other social and practical obstacles.

Insight into infantile amnesia - very young kids can recall early first memories that they subsequently forget.

Fun food names increase children’s consumption of novel healthy foods.

Financial forecasts during the crisis: Were experts more accurate than laypeople?

Physical touch in psychotherapy: Why are we not touching more?

‘Not a neutral event’: Clinical psychologists' experiences of gifts in therapeutic relationships.

What does a great meta-analysis look like?

You probably think this paper's about you. Narcissists' perceptions of their personality and reputation. (ht: @j0ns1m0ns).

Validation of Dunbar's number in Twitter conversations.

The Ghosts of Counseling Psychology: Is Counseling Research Really Dead?

Poorer children have smaller hippocampi.

Humor in Romantic Contexts: Do Men Participate and Women Evaluate?

A longitudinal study of people's regrets.

The neural correlates of human echo-location. (more on this from Ed Yong).

How social influence spoils the 'wisdom of crowd effect'. (more on this from Jonah Lehrer, here and here).

This post was compiled by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

Brain scanning unborn babies to investigate the origins of hemispheric lateralisation.

Media use by people with and without depression.

Children’s belief in an invisible person inhibits their cheating.

The impact of psychopathic traits on relationship satisfaction.

Improving general intelligence with a nutrient-based pharmacological intervention.

Facing an incompetent leader: The effects of a nonexpert leader on subordinates' perception and behaviour.

Do Horses Have a Concept of Person?

Is there an inversion effect for bodies as well as faces? [background]

A case of beat-deafness, a new form of amusia.

Cross-cultural differences in the factors that lead to the formation of flash-bulb memories.

How the sight of overweight people can lead us to eat more.

Tummy rumblings during psychotherapy.

This post was compiled by Christian Jarrett for the BPS Research Digest.

Extras

Eye-catching studies that didn't make the final cut:

Voodoo correlations are everywhere, not just in neuroscience. [Background].

More stats controversy. "There are four major problems with using p as a measure of evidence and these problems are often overlooked in the domain of psychology." Read more.

Differences in how men and women compete. "In two studies, adult human females, compared with males, were more likely to react to the possibility of social exclusion by socially excluding a third party." Read more.

Implicit measures in psychology may be sexy but they're often unreliable. Read more.

Nerves hinder negotiation. "...negotiators who feel anxious expect lower outcomes, make lower first offers, respond more quickly to offers, exit bargaining situations earlier, and ultimately obtain worse outcomes." Read more.

OTOH, mimicking others' language online aids negotiation. "...negotiators who actively mimicked their counterpart's language in the first 10 min of the negotiation obtained higher individual gain compared to those mimicking during the last 10 min, as well as compared to control participants." Read more.

Bi-directional links between semantic memory and sense of identity in older adults. "...autobiographical memory for all time periods (childhood, early adulthood, and recent life) in the semantic domain was associated with greater strength in personal identity. ... However, there was also support for a reverse mediation model indicating that a strong sense of identity is associated with semantic self-knowledge and through this may enhance self-relevant recollection." Read more.

Depth cues in paintings cause people to sway. Read more.

US study finds women are more fearful than men of having their intellectual capabilities tested in public. "...women must overcome fears about doing poorly in public and fears of criticism from others. They must learn to handle criticism without letting it affect the way they feel about themselves. The challenge is to adopt a positive view of their ability as continuously developing and to approach public performances as opportunities to welcome, rather than threats to avoid." Read more.

Praying for a stranger led provoked participants to react with less anger and aggression. Read more.

Don't pick on Dawkins! Reminders of atheist prevalence reduced distrust and prejudice towards atheists. Read more.

Extras

Eye-catching studies that didn't make the final cut:

Is there a crisis in moral psychology?

Stigma against the fat body shape is spreading round the world.

We're more likely to take the stairs (rather than the escalator) if the person before us does. Effect is more modest between strangers.

Experienced therapists' strategies when facing difficult therapeutic impasses.

Listening to music you don't like interferes with reading comprehension.

Can eating disorders become ‘contagious’ in group therapy and specialized inpatient care?

Recalling their past immoral behaviours leads people to compensate by behaving more morally.

A new scale for measuring boredom at school.

Early birds flock together - 'morning' people are more likely to form a relationship with other morning people (ditto for night owls). '...[T]wo extreme chronotypes are unlikely to meet each other because they have the smallest overlap in their preferred active time during the day due to the circadian rhythmicity.'

Bitter tastes make people more likely to feel disgust at moral transgressions.

A forbidden fruit effect: 'implicitly preventing people from attending to desirable relationship alternatives may undermine, rather than bolster, the strength of that person's romantic relationship ...'

One-year follow-up analysis of cognitive and psychological consequences among survivors of the Wenchuan earthquake.

An examination of the influence of routine behaviour on people's feelings of safety, confidence, and well-being.

Becoming ‘whole’ again: A qualitative study of women's views of recovering from anorexia nervosa.

An intergroup investigation of disparaging humor. 'The findings revealed that both men and women exhibited in-group bias by rating jokes about the opposite gender funnier and more typical than jokes about their own gender...'.

'...the breastfeeding confederate was rated significantly less competent in general, in math and work specifically, and was less likely to be hired ... Results suggest that although breastfeeding may be economical and healthy, the social cost is potentially great'.

Extras

Eye-catching studies that didn't make the final cut:

Local effects on people's belief in global warming. Can I call this the Daily Express effect? "Respondents who thought that day [they were surveyed] was warmer than usual believed more in and had greater concern about global warming than did respondents who thought that day was colder than usual"

Social relationships get better with age. Here's why.

Can you pay people to remember better? Only if the material is boring.

The experiences of psychologists from different countries in responding to crises, including natural disasters.

Children as young as five show a preference for other children of the same race. This new study shows the same is not true of infants.

Bad smells encourage condom use.

Frequent sex can stop neuroticism from harming marital satisfaction.

How metaphors affect our reasoning. "We find that exposure to even a single metaphor can induce substantial differences in opinion about how to solve social problems ..." Coverage from Ed Yong at Not Exactly Rocket Science.

An analysis of the role that different aspects of executive functioning play in student procrastination.

Believing more in chance or fate helps people cope with the death of a spouse.

The present research examined who tends to experience music-induced chills and why.

Available in all good toy stores (or maybe not) - the Implicit Association Test for kids.

A clinical study of those who utter threats to kill.

Whatever Happened to Counseling in Counseling Psychology?

People primed to feel more socially secure subsequently placed less monetary value on their possessions.

Creative people are judged as less suitable for leadership positions.

Extras

Eye-catching studies that didn't make the final cut:

Women's brains change in size across the menstrual cycle.

Do positive children become positive adults?

Reminders of death lead people to want to name their children after themselves.

10- to 13-month-old, but not 8-month-old, infants recognise that when big clashes with small, big usually wins.

Nature feature on the 1946 birth-cohort study (pdf).

The illusion of owning a third arm.

People make less impulsive decisions when they have a full bladder (pdf).

The role of working memory capacity in people's ability to perform mental tasks when in pain.

Tended forests had a larger beneficial effect on well-being than wild forests.

A brain imaging study of deliberate forgetting.

Meat-eaters see animals as less human than vegetarians do.

Cultural differences in the perceived intensity of emotion conveyed by people's facial expressions and body language. Co-author Gary McKeown told me: "... the paper advances studies of the universality of the perception of emotional expressions beyond showing static pictures of posed emotional expressions. Instead we showed people in different countries [Serbia, Peru, Guatemala and N. Ireland] video clips of people being somewhat emotional and got them to continuously rate the changes in positive and negative emotion. We found strong similarities in the pattern of perceived emotions, so the ups and downs of positive and negative valence were very similar, providing evidence for the universality of emotional expression. However, we found differences in the intensity to which these were interpreted. The clips featured mostly people from the UK, and the Northern Irish participants saw the most intense levels of emotion (more strictly emotional valence), the other countries varied in the perceived level of intensity although Serbia usually attributed the lowest levels of intensity."

Extras

Eye-catching studies that didn't make the final cut:

Why pop-up ads on the computer don't work and just annoy.

Do people use reverse psychology in everyday life?

Brief and rare mental “breaks” keep you focused.

Men say they're less likely to use aggression towards women than men, regardless of whether that woman is an intimate partner or a friend. In contrast, women say they're more likely to use aggression against a male intimate partner, than either a male or female friend. 'We argued that men’s aggression towards women is lowered because of strong social norms in the West which prohibit male aggression towards women,' lead author Kate Cross told me. 'Women are usually unlikely to use direct aggression, but they become relatively uninhibited about using aggression because of the intimate bond they have with a partner.'

Incorporation of another person's limb into body image relieves phantom limb pain: A case study.

Stress Strengthens Memory of First Impressions of Others' Positive Personality Traits.

Mending broken hearts with a throw of the dice.

It's easier to mentally rotate clockwise than anticlockwise.

“He Loves Me, He Loves Me Not . . . ” Uncertainty Can Increase Romantic Attraction.

'Unexpectedly, the analyses yielded an inverse gender gap with higher values for social dominance orientation in women than in men'. Evidence for gender stereotype reversal in a German sample.

Was he happy? Cultural difference in conceptions of Jesus.

Finally, here's one for Andy Gray and Richard Keys: Establishing and Challenging Masculinity: The Influence of Gendered Discourses in Organized Sport.

Extras

Eye-catching studies that didn't make the final cut:

Tipping estimate/guidance on a restaurant bill increases diners' generosity.

Pain helps assuage feelings of guilt.

How workers compensate for windowless offices.

Marriages are more satisfying when wives are thinner than their husbands.

Does a higher income make you more altruistic?

Understanding the causes of women's underrepresentation in science - less to do with discrimination and more to do with the need for organisations to make it easier to balance work/life demands.

'These results suggest that antidepressant use among individuals without psychiatric diagnoses is common in the United States ...'

A call for clinical psychologists to be trained in psychopharmacology.

Why do we listen to music?

Would you swap your lottery ticket for someone else's? The price people are willing to pay to avoid regret.

Minding the gap between neuroscientific and psychoanalytic understanding of autism.

Reducing people's confidence in their memory leads them to perform more checking behaviour - study with implications for understanding OCD.

More research on healthy habit formation.

Classroom discipline across 41 countries. 'In countries that were poorer, more equal, or had more rigid gender roles, students reported higher classroom discipline'.

Progress in the development of an on-line atlas of the mouse brain.

Attempts to avoid ageism by dressing young could backfire. 'In three experiments we found that both male and female young adults negatively evaluated older adults who attempt to look younger compared to older adults who do not attempt to do so ...'

Cognitive neuroscience 2.0: building a cumulative science of human brain function.

Extras

Eye-catching studies that didn't make the final cut:

The newborn infant: a missing stage in developmental psychology.

I can't believe this isn't wood! An investigation in the perception of naturalness.

Chemical signal in women's tears puts men off sex.

Meta-analyses of brain areas needed for numbers and calculations.

The role of passion in musical achievement - you need to make sure you have the harmonious variety rather than the obsessive kind.

A critical look at the research on psychological debriefing after stressful incidents. Past research suggests it can be harmful but this paper is sceptical. 'We call for reviewers to recognize the limitations of debriefing research and not to overgeneralize their conclusions.'

The disease of the moon: The linguistic and pathological evolution of the English term “Lunatic”

What do we infer about people from the style of their email messages?

Oops! If-then implementation plans with a negating style (e.g. If I am sad, then I won't eat chocolate) can back-fire increasing the to-be-avoided habit.

Exposure to the Confederate flag could have put people off voting for Obama.

Sex differences in dark side traits.

How much do US clinical psychologists know about online research resources?

Reward, dopamine and the control of food intake: implications for obesity.

Speech errors of amnesic H.M.: Unlike everyday slips-of-the-tongue - possibly one of the last studies H.M. took part in.

Extras

Eye-catching studies that didn't make the final cut:

Thermal imaging as a lie detection tool at airports.

'In comparison to their younger counterparts, older adults generally reported and expressed greater sympathy while observing the target persons' - age changes in three facets of empathy.

Participants were able to identify whether a stranger was a Mormon or not, merely based on their facial appearance (and controlling for the presence or absence of facial hair). [open access]

Why do we yawn?

Fact and fiction in the use of cognitive testing in staff recruitment.

Placebos are effective even when patients are told that it's a placebo (at least, for patients with IBS). [open access]

Cortical hubs in the infant brain.

How physical posture affects our feelings of power and our thinking style.

People with larger amygdalae (a temporal lobe structure involved in emotional learning) tend to have larger social networks. [open access]

People high in 'trait positivity' more often rejected unfair offers in an economic game, perhaps because they have a stronger sense of self-worth. [open access]

Rat study shows that stress can re-activate memories that are unrelated to the stressful experience. [open access]

How to deceive your research participants ethically - a guide for researchers.

The woman who experiences no fear.

Extras

Eye-catching studies that didn't make the final cut:

Don't tell Sarkozy: popular politicians are perceived to be taller.

Can you see OK in there? Analysis of uterine conditions suggests that at least some fetuses have enough light to see by. 'This finding could have intriguing implications for the ontogeny of early visuo-motor abilities in newborns and infants.'

People respond to threat warnings differently depending on whether they refer to natural disasters, terrorism or criminal violence. 'It appears that the mechanisms for perception, decision-making, and action in response to threats cannot be generalized in a straightforward way across these domains of threat.'

Pull the other one - overly short or long legs are perceived as less attractive, according to a poll of people across no fewer than 27 nations.

Despite what you might think, jurors weren't biased by the label 'psychopath'.

English and Mandarin speakers think about time differently.

The dark side of emotional intelligence (EI). 'We suggest that high-EI people ... are likely to benefit from several strategic behaviors in organizations including: focusing emotion detection on important others, disguising and expressing emotions for personal gain, using misattribution to stir and shape emotions, and controlling the flow of emotion-laden communication.'

Smoking affects language lateralisation in the brain, and does so differently for men and women.

Distracting the mind improves performance.

Review of when people get violent during sleep.