Nature via Nurture : aggressiveness in Dorsophilia

As per a recent PNAS article , Dorsophilia have a gene called Cyp6a20 which is expressed more in the head when the flies are not socially isolated but have social experience. This increase in gene expression is correlated with a decrease in aggression. Thus, this gene codes for not only the genetic component of the inheritableness of aggressiveness in the Dorsophilia, but also the environmental effect of social stimulus on aggressiveness and how that environmental influence is itself dependent on genes. To make it clear, Dorsophilia that had this gene mutated showed a change in aggressiveness only for flies that were reared in social groups and had no effect when they were reared as socially isolated.

To me, this seems another case where nature and nurture do not necessarily have to work exclusively, but work in concord to give observable phenotypes. It is interesting to note that this same gene is also expressed in olfactory sensilla and this suggest that aggressiveness - socialization effect may be mediated by pheromone effects.

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Psychology Today blogs

I had blogged earlier regarding the Magical Thinking article in Psychology Today. It seems that Psychology today also has a blog by its editors called Brainstorm and in it there are a couple of blogs regarding the same article by the same author and readers may find them wroth checking out.

While we are at it, Psychology Today also has many other blogs of note there and authors include people like Satoshi Kanazawa, Peter Crammer , William Todd Schultz etc. So have a look!

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Genocide and Mortality Saliance

There is an interesting article at We're Only Human, that argues that being exposed to people who have a different philosophy or world-view form our own can lead to feelings of Mortality Salience or awareness of our own Mortality. We all know that humans are aware of their own mortality and yet, can go about their daily business, nonchalantly , as they find solace in their cultural world-view , of being part of a religion or group with shared philosophy/ world-view. This is the basis for the Terror Management theory.

Now the article further argues, that if we witness the annihilation of people whose philisophy / world-view is different from ours , and who by their mere presence have induced a Mortality salience in us; then we can , by witnessing their annihilation, overcome the terror of death and manage its impact. thus, our propensity for genocide. all this is not based on mere speculation, but there is experimental evidence, that thinking about people with a different philosophy does lead to thoughts of personal death and fear of ones mortality; that witnessing or being told about the death of members holding that alternate philosophical view does lead to proper management of that terror and thus theoretically the rationale of hidden reasons behind genocide.

All that is fine; but the research was conducted using a religious paradigm. what if the other group exposed to was that of atheists; or a capitalist group was pitted against communist ideologies; would the results still hold. Historically, there has been much bloodshed between religious factions, and memories of that may color the results as people realistically feel threatened due to the checkered history of mankind. If we can be user that the terror is due to mortality salience induced by exposure to different philosophy ; and not just due to memories flooding back; than the results could have a greater implication.

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Brain Feminization of males with schizophrenia?

I don't really know what to make of Mendrek's results as discussed in this article that claim to have discovered “masculinization” of females and “feminization” of males with schizophrenia (at least at the neuroanatomical level).

The study, that used emotive film clips and fMRI to find the pattern of activation on watching emotional stimulation in a schizophrenic population, did not have any normal controls. Thus, while the fact that their results showed greater activation in Males as compared to females may be true, they do not tell us how this is related to the activation in normal population? Are schizophrenic in general more emotional than baseline normal people or less emotional is not clear. It is presumed that the baseline normal activity falls midway from what was observed in males and females and thus males more feminized while females more masculanized.


I also do not know how to integrate this finding with my framework that sees Autism and Schizophrenia/ psychosis as opposite ends of spectrum. If we juts limit our discussion to Males, then everything seems fine. Autism is the 'extreme male brain' theory while schizophrenia in males is 'feminization' of Masculine brain. but what when we extend the ambit to cover females. should one posit that schizophrenia is characterized by movement away from gender based brain development; while Autism is characterized by movement towards gender specific brain development. In this case one would conclude that female autistics were an extreme female brain. I don't like this argument as there seems scarce evidence for that. I would instead argue that even females in Schizophrenia are more feminized and this may have to do with the imprinting genes that we have discussed earlier. If the evidence was there that both males and females are more feminized in schizophrenia, life would be simple. Let me know what you think in comments and of any evidence you may be aware of.

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A Schizophrenia quiz

I always believe that questions and quizzes are an integral part of learning and retaining new information. So from now on , I'll be regularly posting some quiz questions on a particular topic on the left had side bar of The Mouse Trap. You have to click on the 'next question' button to get at the first question. Then you have to click the buttons on the top of each alternative for the correct answer. The tool keeps track of your number of tries and correct responses and also provides explanations for the correct answers.

I intend to use this tool extensively in the future. do let me know, whether you find the tool useful and would love to see similar quizzes hosted on the Mouse Trap.

I know that many of you read the Mouse trap as part of an RSS blog reader. However, I would request you to visit The Mouse Trap and give this a shot.

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And we thought only humans have art

Another Human 'unique trait' bites dust. It seems elephants can make self-portraits. Please see the video at the link below.

Elephant makes self-portriat

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Autism, the middle cingulate and reputation management

There was an article on which I had wanted to comment earlier. the study by Chiu et al shows that in autistic individuals the middle cingulate cortex is hypofunctional during the self phase of the iterated Trust game, wherein one has to infer the mind of another, decide whether to trust him or her and accordingly decide what money to give to the trustee and what to keep for oneself.

Recent work using the multiround trust game has identified activations along human
cingulate cortex consistent with agent-specific response patterns generated during interpersonal exchange with another human. These patterns differentiate outcomes following revelation of the partner’s decision (‘‘not self’’ or ‘‘other’’ response) from those following submission of one’s own decision (‘‘self’’ response). Remarkably, the patterns are spatially complementary , and almost no manipulation perturbs them except one: the removal of the interactive partner . Removal of the social partner causes the cingulate response patterns to disappear even though the sensory, motor, and reward elements of the task remain intact. These results from the trust game are consistent with agent specific cingulate responses observed in a range of other experiments. Anterior and posterior cingulate activation occurs in response to the revelation of decisions of others in two-person games like the Ultimatum and Prisoner’s Dilemma games. Furthermore, increased middle cingulate activation is commonly observed in response to one’s own social decisions or emotions.

Chris and Uta Frith do an excellent job of putting these findings in perspective and argue that the autistic is less concerned with reputation management (as it has inability to infer others mind states it does not care hat they think) and suggest a simple experiment that could elucidate the point.

Our speculation is that this process of reputation management is impaired in autistic individuals, because it depends on the ability to read the minds of others. This hypothesis can be tested experimentally. If we are concerned with our reputation then our behavior will be strongly affected by whether or not an audience is present to observe our actions. Consider, for instance, another sharing game known as the dictator game. One player is given $100 and is allowed to share any amount he or she chooses with the other player. In this situation, the rational thing to do would be to give the other player no money at all, because the second player is powerless to respond. Even "dictators" will typically dole out a small proportion of the money, however. When there is an audience for the transaction, dictators give away even more money. Presumably, they do not want to have a reputation for meanness or for acting unfairly. If autistic people are not concerned with their own reputation, then their behaviour should not be affected by the presence of an audience.

I would like to extend their experiment and suggest one for those susceptible to psychosis. I have argued that Autism and Schizophrenia/ psychosis are extreme ends of a continuum and would thus conclude that in the iterated trust game, psychotics/ those susceptible to psychosis would show hyperfunctioning of middle cingulate cortex. I have elsewhere already argued that Psychotics have an enhanced ToM or mind reading ability. I would also hypothesize that psychotics would also show enhanced reputation management and an enhanced donation of money in the trust game when an audience is present as compared to controls or the autistics.


While an experiment is the best to settle such conjectures, it is tempting to see how this adds up and can explain certain symptoms of psychosis/ mania. If one is overly concerned with reputation management one can end up being a spendthrift / show irresponsible financial behavior as one tries to build a hypothetical reputation in the minds of the audience. Taken with the fact that psychosis comes clubbed with a belief in supernatural agents, magical thinking and super agency detection etc, one may not even need an actual audience - a make-believe audience may suffice to make one get overly concerned with reputation management and thus trusting too much the others -even with their money. when reality proves otherwise and people prove to be not worthy of the trust, one may dissociate with reality altogether and become paranoid on the other extreme. We know that the ACC is dysfunctional in schizophrenics, what about the middle cingulate? is it hypoactive during trust games in the self condition? Only a hypothesis, but worth investigating!

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Stress contagion: from parents to the child?

Greg Downey at the excellent Neuroanthroplogy blog comments on a recent article by Mary Caserta, on the relationship between parental stress and illness in the children and the child's immune response. What the research team found was that :

Family processes have a substantial impact on children’s social and emotional well-being, but little is known about the effects of family stress on children’s physical health. To begin to identify potential links between family stress and health in children, we examined associations between specific aspects of family psychosocial stress and the frequency of illnesses in children, measures of innate and adaptive immune function, and human herpesvirus 6 (HHV-6) reactivation

Greg, thinks of several possible reasons for this association:

1. Stressed out parents interact differently with their children and stress them.
2. Mirror neurons or similar systems may underlie the fact that the child may be mirroring the internal stressed environment of the parent and consequently feeling stressed.
3. Chemical mechanisms including pheromones released on being stressed (!!) may be at work and responsible for the contagion.
4. Reverse causation: the stick children may be causing the parents to feel more stressed.

I find all the above explanations (except 3) interesting and plausible, but Greg has also ignored another potential reason. Being an anthropologist he has overlooked the genetic aspect. What if some underlying gene which endows the parent to feel more stressed is also responsible for the children being more susceptible to illness/ having more auto-immune response. After all the stress system and immune system are very much cloistered together. It is not hard to imagine that a gene that causes vulnerability to stress( or felling stressed) also increases sensitivity to environmental pathogens and sensitivity of immune response. As the child is sharing 50 % of the gene of the parent, there is a great likelihood that the sensitivity to stress and sensitivity to pathogens may be inherited in the same manner. Food for thought.

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