Posterior Medial Prefrontal Cortex Modulating Conformity


When Transcranial Electromagnetic Stimulation (TMS) was used to inhibit the activity of the neurons in the posterior medial frontal cortex, the participants did not change their ratings of the photographs so they were more in line with the rest of the group.
Dr Klucharev believes this part of the brain is responsible for generating an “error” signal when individuals deviate from the group opinion, triggering a cascade that leads them to conform with the group view.
He said: “What if that mechanism could be suspended for a time? The group who were exposed to the TMS changed their views to a much lesser extent – they were immune to ‘group pressure’.
“Individuals differ in the strength of the error signal – which is why some people are more conformist than others. It also tells us that conformity is a rather automatic process that is based on an old evolutionary mechanism.”

Read the rest of the article at: The Telegraph


Serotonin: Human social intimacy/connection and romance


Healthy adult volunteers, whose levels of serotonin activity had been lowered, rated couples in photos as being less intimate and less romantic than volunteers with normal serotonin activity.

The approach involved giving amino acid drinks to two groups of volunteers in order to manipulate blood concentrations of the amino acid tryptophan, which is a vital ingredient in the synthesis of serotonin. One group received drinks that contained tryptophan. The other group received drinks that did not contain tryptophan. They were then asked to make judgments about sets of photographs of couples. Differences in the judgments made by the two groups reflected changes in their serotonin activity. [...]

The results raise the possibility that lower serotonin activity in people with depression and other psychiatric conditions could contribute to changes in the way they perceive personal relationships, or even in their ability to maintain positive personal relationships.

“Although this is only a small study, the same patterns may well extend to the way we perceive our own relationships,” said Professor Rogers. (via.)


Thirst Reduces Stress Response: “The Watering Hole Effect”


Assuming this is conserved in humans, the following passage might suggest that it’s better that you walk into an interview a little bit thirsty:

“We’re calling this the Watering Hole Effect,” says Eric Krause, PhD, a research assistant professor in the basic science division of UC’s department of psychiatry and behavioral neuroscience and first author of the study. “When you’re thirsty, you have to overcome some amount of fear and anxiety to approach a communal water source. And you want to facilitate those interactions—that way everyone can get to the water source.”

Krause and his team dehydrated laboratory rats by giving them sodium chloride, then exposed them to stress. Compared with a control group, the rats that received the sodium chloride secreted fewer stress hormones and also displayed a reduced cardiovascular response to stress.

“Their blood pressure and heart rate did not go up as much in response to stress as the control group’s, and they returned to resting levels more quickly,” says Krause.

“Also, in a social interaction paradigm with two rats interacting, we found them to be more interactive and less socially anxious.”

Further research, through examination of brain and blood samples from the rats, showed that the same hormones that act on kidneys to compensate for dehydration also act on the brain to regulate responsiveness to stressors and social anxiety.

The elevated sodium level, known as hypernatremia, limited stress responses by suppressing the release of the pro-stress hormone angiotensin II. Conversely, it increased the activity of oxytocin, an anti-stress hormone. (via.)

Thanks to hugthemonkey for pointing this one out on Twitter. Susan also posted a link to this interesting gem recently: A study led by Jillian O’Connor, a graduate student in the Department of Psychology, Neuroscience & Behaviour at McMaster University, found that people think they can predict whether a mate will cheat by listening to tone of voice.


Females, Dominance, and Social Exclusion Tactics


Many studies have suggested that males tend to be more physically and verbally aggressive than females. According to a new study, to be published in Psychological Science, a journal of the Association for Psychological Science, it may not be the case that women are less competitive than men—they may just be using a different strategy to come out ahead. Specifically, women may rely more on indirect forms of aggression, such as social exclusion. [...]

“As their primary competitive strategy to combat any social threat, females may attempt to form an exclusionary alliance, whereas males may endeavor to unilaterally and directly dominate an opponent,” the authors write. Women may be more sensitive than men to social exclusion, and when they feel threatened by the prospect of being left out, a woman’s first response may be to socially exclude a third party.

Preemptive social exclusion appears to be a valuable strategy for women because it allows them to protect their relationships by keeping an outsider at bay. Benenson points out that this may require a re-evaluation of presumed sex differences in competitiveness. She comments, “The same-sex social worlds of boys and girls and men and women then differ in that females have to worry about alienating others, whereas males worry about getting beaten up.” (via.)

Basically, their conclusions came from a game that men and women both played. Follow the via link for more information.


Kleine-Levin Syndrome: Sleep 10 days at a time? You might have it.


“I was hallucinating and after that I don’t remember anything. All of a sudden it just went blank and I just slept for 10 days. I woke up and I was fine again.” [...]

“I was hallucinating and after that I don’t remember anything. All of a sudden it just went blank and I just slept for 10 days. I woke up and I was fine again.” [...]

Louisa is unusual as KLS usually affects teenage boys, who can also exhibit hypersexuality and inappropriate behaviour.

As well as excessive sleeping, symptoms include behaviour changes, irritability, feeling in a dream-like state and binge eating, symptoms that can be mistaken for normal teenage behaviour. [...]

The change in behaviour before and during a sleep episode is one of the most upsetting things for Louisa’s parents, who take it in turns to remain with her. Doctors have told the family it’s crucial to wake Louisa once a day to feed her and get her to the bathroom.

But Lottie admits it can take a while to get her to come round. “I’ve tried before to literally force her to wake up but she just starts swearing and gets so agitated and aggressive.” [...]

Many sufferers have abnormalities in their temporal lobe, the area of the brain involved in behaviour and memory. A scan of Louisa’s brain function revealed she does have abnormalities in her frontal lobe but there are no signs that this has affected her behaviour or memory. (via.)


Social component key to link between happiness & religiosity


According to the study, 33 percent of people who attend religious services every week and have three to five close friends in their congregation report that they are “extremely satisfied” with their lives. “Extremely satisfied” is defined as a 10 on a scale ranging from 1 to 10.

In comparison, only 19 percent of people who attend religious services weekly, but who have no close friends in their congregation report that they are extremely satisfied. On the other hand, 23 percent of people who attend religious services only several times a year, but who have three to five close friends in their congregation are extremely satisfied with their lives. (via.)


East & Western Cultural Values: Honesty, Dominance & Submission


When an American thinks about whether he is honest, his brain activity looks very different than when he thinks about whether another person is honest, even a close relative. That’s not true for Chinese people. When a Chinese man evaluates whether he is honest, his brain activity looks almost identical to when he is thinking about whether his mother is honest.

That finding — that American and Chinese brains function differently when considering traits of themselves versus traits of others (Neuroimage, Vol. 34, No. 3) — supports behavioral studies that have found that people from collectivist cultures, such as China, think of themselves as deeply connected to other people in their lives, while Americans adhere to a strong sense of individuality.

Different study, but from the same article:

Ambady’s group based the study on historical data showing that East-Asian cultures value submissiveness, while Western cultures value dominance. In fact, they found, they could see this cultural distinction in the way the brain responds to visual input. When Americans viewed dominant silhouettes, but not submissive ones, reward circuitry fired in the brain’s limbic system. The opposite happened among Japanese participants; their reward circuitry fired in response to submissive, but not dominant, silhouettes.

… same article:

Most recently, a study by Park’s group, in press in Social Cognitive and Affective Neuroscience demonstrated that Westerners process human faces more actively than East Asians, consistent with the Western focus on individuality.

… last interesting tidbit:

The researchers sought to find a biological explanation for past research showing that people from collectivist cultures relate more strongly to contextual self-descriptions, such as “When I’m with my mother, I’m honest.” People from already defined individualistic cultures relate more strongly to general self-descriptions such as “I’m honest.”

When Chiao and her colleagues compared participants along ethnic lines, they saw no difference in brain activity. Differences appeared only after they grouped people based on how strongly they valued collectivism or individualism: Regardless of ethnicity, the medial prefrontal cortex was most active when individualists read general self-descriptions and when collectivists read contextual self-descriptions.

via.


Fewer 5HT2a (serotonin) receptors in pcc & acc in autistics


The posterior cingulate cortex (PCC) is activated when normal subjects see faces or hear voices of emotionally significant people in their lives; however, in autism the level of activation is impaired. [...]

The use of selective serotonin reuptake inhibitor (SSRI) medication has been shown to be successful in the treatment of autistic behaviors in some individuals. Serotonin (5-HT) has a role in neuronal development and has been extensively studied in autism with reports of excess 5-HT in the blood (hyperserotonemia) in some people with autism. [...]

The results show that there was a significant decrease in the density of one key type of serotonin receptor, the 5HT2A receptor, in the superficial cortical layers of the PCC in the adult autistic group when compared to age-matched controls. Similar results were found recently in the anterior cingulate cortex, an area involved in social-emotional processing. Evaluated together, these findings suggest that the 5-HT2a serotonin receptor decrease occurs in widespread cortical areas and may play a central role in some of the social deficits observed in autism. (via.)


A tilt of the head influences perceived attractiveness


“A gap in our knowledge, however, is the evolutionary origin of what is considered masculine and feminine about facial features. Our research investigated if looking at the face from different perspectives as a result of the height differential between men and women influenced perceived masculinity or femininity. The research found the way we angle our faces affects our attractiveness to the opposite sex.”

Men, typically taller than women, view a woman’s face from above; and women view men’s faces from below. [...]

The research found that female faces are judged to be more feminine and more attractive when tilted forwards (simulating viewing from above), and less feminine when tilted backwards (simulating viewing from below). Conversely, male faces are judged more masculine when tilted backwards and less masculine when tilted forwards. (via.)

Geometry skillz for enhanced sexual attractiveness, baby. If that isn’t weird I’m not really sure what is.


The upper-class and empathy


One experiment used volunteers who worked at a university. Some had graduated from college and others had not; researchers used educational level as a proxy for social class. The volunteers did a test of emotion perception, in which they were instructed to look at pictures of faces and indicate which emotions each face was displaying. People with more education performed worse on the task than people with less education. In another study, university students who were of higher social standing (determined from each student’s self-reported perceptions of his or her family’s socioeconomic status) had a more difficult time accurately reading the emotions of a stranger during a group job interview.

These results suggest that people of upper-class status aren’t very good at recognizing the emotions other people are feeling. The researchers speculate that this is because they can solve their problems, like the daycare example, without relying on others—they aren’t as dependent on the people around them.

A final experiment found that, when people were made to feel that they were at a lower social class than they actually were, they got better at reading emotions. This shows that “it’s not something ingrained in the individual,” Kraus says. “It’s the cultural context leading to these differences.” He says this work helps show that stereotypes about the classes are wrong. (via.)