The dark side of oxytocin

Oxytocin is usually described as the ‘trust hormone’ owing to its involvement in social bonding but a new study covered by Scientific American suggests it may have a wider role in human interaction as it has been found it increase feelings of envy and gloating.

The study, led by psychologist Simone Shamay-Tsoory, used a familiar format in oxytocin research. It asked participants to play a competitive game while half were given a nasal spray containing the hormone and half were given a placebo spray.

Although they thought they were playing another participant, in reality, they were playing a computer programmed to act in a certain way to elicit competitive emotions:

The computer was programmed to either win more money than the players to trigger feelings of envy, lose more money to elicit a form of gloating known as schadenfreude (delight over another’s misfortune) or to win or lose equal amounts of money. To encourage these negative emotions, the researchers gave the computer player an arrogant “personality”. They did this by asking the volunteers to appraise their chances of winning more money than the other player; although nearly all volunteers predicted 50-50 odds, they were told their opponents gave themselves an 80 percent chance of winning.

When compared with a placebo, volunteers who inhaled oxytocin said they felt greater levels of envy or gloating when they lost or won more money than the computer, respectively‚ findings the researchers detailed online July 29 in Biological Psychiatry. On the other hand, when the volunteers were questioned after the game, inhaling oxytocin apparently had no effect either following gains of equal amounts of money or on mood in general.

The researchers also measured mood in general and found no change, suggesting the increase in negative feelings toward others couldn’t be explained as a general intensifying of emotions.

In their paper, they note several exceptions to the media stereotype that oxytocin is a ‘hug hormone’, citing studies that it increases aggression and territorial defence in some species. Also contrary to the cliché, a recent study [pdf] found it had no effect on empathy for other people’s pain.

They conclude that, rather than being a something that promotes trust and bonding, oxytocin enhances all social emotions, including the good, the bad and the ugly.

Link to SciAm on oxytocin and envy study.
Link to abstract of study.

Seized by Voodoo spirits

I’ve just found a remarkable paper with several cases of epilepsy that were interpreted as voodoo possession. They were all people with roots in Haiti, where voodoo is the predominant religion, and where spirit possession is considered a common spiritual event.

For thousands of years epilepsy has been explained as spirit possession in religions around the world. Epilepsy is also known to trigger intense religious or spiritual experiences in some people but the majority of cases are from the West and so have a distinctly Christian theme.

This 36-year-old woman had several years of recurrent complex partial seizures that manifested as a strong sense of fear and epigastric coldness, followed by loss of awareness, utterances of nonsensical phrases, and complex motor automatisms. The local mambo attributed the events to her being taken by “Melle Charlotte,” a french loa [spirit], with the nonsensical speech being interpreted as a foreign language.

It is said that during the possession by this spirit, a person will speak perfect French or other languages, even though in life, the person has no knowledge of that language. She continued to have seizures despite the mambo’s attempts to conjure the spirit. He explained his failure to the fact that Melle Charlotte is a very particular loa who makes only sporadic appearances. She was not treated with AEDs [anti-epileptic drugs] until she left Haiti at the age of 34.

An EEG revealed a right anterior temporal focus, and magnetic resonance imaging (MRI) showed right hippocampal atrophy. Seizures improved with carbamazepine (CBZ), although compliance with medication was a problem, largely because of family interference.

The cases are interesting as they highlight how easily the ‘possession’ theory fits with the unpredictable course of epilepsy and its effects when it seems to briefly ‘take over’ the body and mind of the affected person.

It raises the question of how much observations of epilepsy, a condition that affects approximately 1% of the population, have contributed to the idea of possession throughout the world.

Link to paper on epilepsy and Voodoo experiences.
Link to PubMed entry for same.

Like running through hell

The Neurocritic covers some fascinating research on how marathon runners could be a scientific window into the neuropsychology of trauma owing to the fact that they experience extremely high levels of the stress hormone cortisol.

In their study, psychologists Teal Eich and Janet Metcalfe note that cortisol levels recorded 30 minutes after a marathon have been found to be similar to those in soldiers during military training and interrogation, rape victims just after the attack, severe burn injury patients and first-time parachute jumpers.

This suggests that marathon runners could be studied in a more systematic way than would would be ethical with victims of trauma, giving an important insight into the brain under extreme stress.

Eich and Metcalfe were particularly interested in the effect of stress on memory and wanted to see if there were any differences between explicit memory – memories that you can consciously call to mind, and implicit memory – the influence of past information on a task even if you’re not aware of doing any remembering.

They tested a group of runners about half an hour after they completed a marathon and a group who were just about to run a marathon.

In comparison to the about-to-runs, those who had completed the marathon had worse explicit memory but better implicit memory. In other words, their conscious memory was reduced but their unconscious memory seemed to be sharper.

This is interesting because chronically high cortisol levels from trauma are thought to affect the hippocampus, a brain area known to be key in conscious memory. The researchers suggest that a similar process may be temporarily reducing explicit memory in runners.

The authors are a little more cautious in suggesting why implicit memory may have been improved, but one possibility is that cortisol is known to affect fear conditioning – the unconscious linking of fright with the situation it occurred in.

Interestingly, this is known to work differently in men and women. Cortisol boosts unconscious fear learning in men, but not women. The researchers didn’t compare male and female marathon runners directly, but it would be interesting to know whether general unconscious learning that wasn’t associated with fright was also sex-specific in their study.

There’s more on the research over at The Neurocritic and the full text of the study is available online as a pdf if you want an in-depth look at the experiment.

Link to great write-up from The Neurocritic.
pdf of study.
Link to PubMed entry for same.

Metro psychiatry

Photo by Flickr user thebigdurian. Click for sourceThis month’s British Journal of Psychiatry has a poignant poem by Canadian poet and psychiatrist Ron Charach who muses on ‘Psychiatrists on the Subway’:

Apparently the poem is from his collection Selected Portraits that contains a number of other poems on psychiatry and mental illness.

Psychiatrists on the Subway

One rarely spots psychiatrists on the subway
rubbing the haze of a long day’s sessions
from their lean temples,
or thumbing through paperbacks that deal
with anything-but.

Wouldn’t they like an update on who’s
In the world and how they’re doing?
Or would the ridership be wary of men and women
whose briefcases rattle with the tic tac
of pills, whose ears perk
like armadillos’ at conversations
two seats over?

More likely we locate them in a bad joke,
in a wing-chair beside a firm couch,
a suicide statistic, a product seminar
with deli sandwiches courtesy of Pfizer or Roche
or Eli Lilly;
perhaps on the beach of a convention hotel
with a panorama of thong-clad beauties
who seldom talk revealingly

Before bed a psychiatrist sets his ears
on the night-table
and prays for a night of long silence
from a god who prefers
to listen.

You can hear Charach himself reading poems from the collection, including ‘Psychiatrists on the Subway’ at this page. He reads in a calm deliberate manner which really suits the material.

Link to poem in the British Journal of Psychiatry.
Link to Charach reading his poetry.