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Archive for the ‘culture’ Category

Edge.org briefly taps into a most important topic: is China going to be the next leader in science and economy? Many observers tend to think this, and it is iterated in the media regularly. In terms of economy, we may expect this to be the case. The sheer amount of people, combined with lower rates of salary etc. suggests that for a period, China will be competitive not only in industy but also high-tech jobs.

But in science? I usually think of science as either basic or applied (although they can be mutually informative, and the distinction is not water proof). For applied science, like engineering, IT and so forth, one may expect that Chine may do well. But in basic science, what we often encounter is surprising, unexpected, and, not the least, runs straight counter to our wide-held beliefs. And the realization of these ideas depend on whether the state are basically tuned to accepting scientific results.

Think for example, how often you hear science news that actually alter your thought about the human/animal mind, the world and cosmos, and so forth. Many of these ideas run straight counter to widely and long-held beliefs in society and even academia. Think of our understanding of the role of unconscious (often emotionally driven) brain processes in decision making. Or, one of our favourite topics here: how genes contribute to specific differences between people’s brains, minds and behaviour. These ideas run straight counter to ideas in religion, economic theory and social science. But they are nevertheless expressed freely, through the peer-reviewed scientific thought.

So the question could be put differently: could ideas about evolution and evolutionary psychology, quantum mechanics, or the Big Bang ever come from scientists residing in China? Several authors and observers may think not. Although this is NOT the topic of the Edge.org issue, the brief title of the news, and the afterword by Dawkins suggests that it deserves more attention.

-Thomas

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humphrey.JPGIt was twenty years ago today. Sgt. Pepper taught the band to play.

Actually, last year it was 30 years ago that Nicholas Humphrey published his seminal paper “The social function of intellect” (pdf). Many people see this paper as the impetus to later work on the social brain hypothesis (pdf) and Theory of Mind. Humphrey suggested that, rather than the need for technology, it was in fact the need for advanced cognitive mechanisms for keeping track of conspecifics and interacting with other members of their social group that drove the expansion of brain and intelligence in hominids. This idea has provoked research into the role of cooperation and collaboration as well as deception and competition in primate social behaviour. It has prompted research into the importance of conspecifics being able to attend to a shared mental content. (Shared attention appears crucial to the transfer of knowledge in a social group, and is therefore probably a prerequisite for the establishment of cultural traditions.) Finally, it has been instrumental in getting neuroscientists interested in the neurobiological underpinnings of social cognition, including research into Theory of Mind and mirror neurons.

To commemorate Humphrey’s paper and track the above-mentioned ensuing research, the Royal Society of London staged a Dicussion Meeting last year. The papers presented at that meeting have now been published in the latest issue of the Philosophical Transactions of the Royal Society B. It is a veritable smorgardsbord of big names: There’s papers on social intelligence in birds, hyenas, dolphins and apes by, inter alia, Nathan Emery, Nicola Clayton, Kay Holekamp, and Richard Connor. Richard Byrne and Andrew Whiten discuss the animal cultures hypothesis. There’s papers by Michael Tomasello and Daniel Povinelli on ToM in primates. Vittorio Gallese explains the importance of mirror neurons, Chris Frith reviews what we know about the social brain, and Steven Mithen speculates that farming may have arisen from a misapplication of social intelligence. Naturally, Humphrey is also given the opportunity to revisit his 1976 paper.

If you are at all interested in the question of what makes some species social beings you will want to check out this issue.

-Martin

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ubuntu-logo.pngSuffering from a full computer breakdown, my IBM Thinkpad has become sucpiciously reluctant to re-install Windows. Instead, I’m now running Ubuntu linux. For the most part it is not just comparable to Windows, in many respects it’s even better.

So what does this computer havoc have to do with the brain, or ethics at all?

Ubuntu is a totally free computer software, a fully operational operative system that replaces Windows fully. As in the core spirit of the linux movement, everything is free. So who benefits — besides myself — from this genuine altruism? I’m actually quite puzzled as to how I could explain that someone would spend a lot of their time making software without charging me anything for it. (more…)

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beer.jpgAs noted in my previous post, the impact of alcohol on brain maturation in adolescence is still considered an open question, although studies indicate that early exposure to alcohol is even more damaging in adolescence than in adulthood. It’s not surprising at all. Alcohol crosses the blood-brain barrier to influence the function of neurons. Actually, influence is not the right term: intoxicates or poisons the brain is more correct. After all, the effect of alcohol on your state of mind is due to a state of intoxication.Alcohol is of course only one of many substances that have an impact on brain function, and that are used for recreational purposes. Other psychoactive substances include nicotine/tobacco, cannabis, cocaine and LSD. In a population of adolescents the young vary in their use of such drugs, both the debut, the regularity of use, and the combined – or polydrug – use. The question is, then, what causes this variation?

In a special issue of Behavioral Genetics the genetic and environmental causes of substance use are explored and reviewed. For example, Jason Pagan and colleagues study the causes of alcohol use in adolescence, and conclude that

(…) there was no significant evidence of shared environmental influences on alcohol problems in early adulthood. Problems were largely influenced by genetic factors that overlapped with genetic influences on frequency of use. Unique environmental factors were largely specific to each stage, with some overlap between alcohol problems and frequency of use at age 25.
Danielle Dick and her colleagues, on the other hand, find that a specific gene, GABRA2, shows two specific patterns in relation to adolescent and adult alcohol abuse. First they found that aconsistent elevation in risk for alcohol dependence associated with GABRA2 is not evident until the mid-20s and then remains throughout adulthood. On the other hand, GABRA2 was also associated with other drug dependence in their sample, both in adolescence and adulthood. So this gene can indeed be a causative factor in the forming of drug use in general, which some findings seem to indicate. GABRA2 has been shown several times to be coupled to alcoholism. For example, Danielle Dick herself has published data showing a complex relationship between martial status, alcohol dependence and GABRA2, concluding in another publication this year:

These analyses provide evidence of both gene-environment correlation and gene-environment interaction associated with GABRA2, marital status, and alcohol dependence. They illustrate the complex pathways by which genotype and environmental risk factors act and interact to influence alcohol dependence and challenge traditional conceptualizations of “environmental” risk factors.
Anyway, the special issue in Behavior Genetics has several good articles on the gene-environment interaction effects on the development of substance use disorders. It’s a must-read to anyone interested in genes, brain and behaviour.

-Thomas

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alcohol.gifAdolescence is a period of dramatic transformation in the healthy human brain, leading to both regional and general brain volume changes. Recent high-resolution Magnetic Resonance Imaging (MRI) studies emphasize the effects of ongoing myelination, indicating a substantial maturation process (see Figure 1). The period of adolescence is often defined as spanning the second decade of life, although some researchers expand their definition of adolescence to include the early 20s as well. Research into brain maturation in adolescence is particularly important, given that it is normally considered the peak period of neural reorganization that contributes to normal variation in cognitive skills and personality Additionally, it is seen as the period of major mental illness onset, such as schizophrenia. Despite growing evidence for pronounced changes in both the structure and function of the brain during adolescence and early adulthood, few studies have explored this relationship directly using in vivo imaging methods. Thus, little is still known about the relationship between adolescent behaviour and outcomes, and maturational effects on morphological and functional aspects of the brain.

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Figure 1Brain development during adolescence

The psychological and social changes of that occur during adolescence include a higher level or orientation towards and identification with peers, group socialism and personality consolidation. A main social behavioural change is the tendency to use alcohol and other stimulants. In European countries and especially Denmark, 60% of all adolescents report having had their first alcoholic whole drink before age 15, the majority reporting a debut at around age 12 (see Figure 2). Today, alcohol is considered a normal part of adolescent culture.

 

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Figure 2Age of alcohol use debut, as measured by the first consumption of a full alcoholic unit. Note that the majority of debuts are around 12 years. Furthermore, note the relatively high number (8%) reporting a <9 year old debut. (x-axis numbers indicate age of reported first full drink of alcoholic beverage; “yngre end 9” = “younger than 9”; “jeg har ikke drukket” = “I have not yet tried alcohol”)

The effects of prolonged regular alcohol consumption in adults are today considered well documented. Studies of extreme cases such as Wernicke’s encephalopathy and foetal alcohol syndrome have shown that alcohol at critical periods or over time can have severe effects on significant modification and damage of brain structure, physiology and function. In adults, heavy alcohol consumption results in atrophy of grey and white matter, particularly in the frontal lobes, cerebellum, and limbic structures. Heavy drinking also raises the risk of ischemic and hemorrhagic stroke.

Adolescents tend to drink larger quantities on each drinking occasion that adults, possibly a combination of lower sensitivity to some of the unpleasant effects of intoxication and altered patterns of social interaction, including a willingness to indulge in more risky activities. However, it has been suggested that adolescents may be more sensitive to some of alcohol’s harmful effects on brain function. Research now suggests that, even over the shorter time frame of adolescence, drinking alcohol can harm the liver, bones, endocrine system, and brain, and interfere with normal growth. Studies in humans have found that alcohol can lower the levels of growth- and sex hormones in both adolescent genders.

Recent studies using animal models have demonstrated that the adolescent brain is even more sensitive to alcohol consumption. Alcohol inhibits normal neurogenesis, the process in which neurons are created. The magnitude of this effect has been related to the level of consumption; higher levels of consumption (e.g. binge consumption) had the most severe effects on the brain. Furthermore, alcohol impairs spatial memory function in adolescent animals more than adults, a result that is thought to be mediated by a larger inhibitory effect of alcohol on neural transmission in adolescence.

The long-term effects of alcohol consumption on brain maturation are yet poorly understood in human adolescence. Studies report that a history of high alcohol consumption in adolescence has been associated with reduced hippocampal volumes (see Figure 3), and with subtle white-matter microstructure abnormalities in the corpus callosum. In order to understand the effects of alcohol on the brain these findings must be compared to several factors pertaining to alcohol consumption in young adults, including 1) onset of alcohol use; 2) amount of alcohol consumed regularly; 3) type of alcohol consumption (regular use or binge drinking). In addition, a number of confounding factors need to be addressed and controlled between different study groups, including 1) general cognitive function; 2) the effects of gender and pubic stage; 3) gender-related preferences for alcoholic beverages; and 4) the effects of gene-related differences in neurotransmitter function.

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Figure 3Hippocampus volume differences in adolescents with alcohol use disorder (AAU, right) compared to healthy adolescents (left). Volume estimation is corrected for general brain size.

So who says alcohol is not damaging? We know it is in adults. We know it is in prenatal development. Why not during adolescence? Even more so; during this period of brain development so much is happening; the continuation of brain development; pruning and consolidation of brain, cognition and personality; all combined with the coctail of changes resulting from hormonal changes. Add alcohol, and in heavy doses in binge drinking, and you’ve got a recipe for brain dysfunction and detrimental brain development.

In most cultures, alcohol is seen as acceptable, even for adolescents. Alcohol is possibly even more problematic in countries such as Denmark, since it is not illegal for children and adolescents to drink alcoholic beverages (although it is strangely enough illegal for them to buy it; i.e. they have to get it from their parents or another >15 year old). Statistically, Denmark ranges among the countries that has the earliest alcohol debut and the highest mean weekly/monthly alcohol consumption in adolescence. In general, alcohol is more socially and culturally accepted in the Western world (or all cultures?). But given that alcohol has such damaging effects should we allow it if it turns out to have detrimental effects on brain development and cognitive functions?

You can put it another way: given that you know this, would you allow your teenage son or daughter to drink alcohol? If you knew that her or his brain would respond negatively (both long and short term) to the alcohol, would you let it happen? Thick twice

-Thomas

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prejudice2.jpgIs your social brain wired to differ between how you relate to other people? Is your basic empathic ability changing – in the brain – according to whether you can relate to another person or not? Following some very interesting findings in a study reported in a Neuron article, the brain makes such a difference. Neuroimaging is consolidating its role in the domain of social psychology.

The study comes from the Banaji’s laboratory at Harvard. In the study the researchers showed a group of college students pictures of two target individuals who were described as having liberal or conservative political views — a step designed to make the students either identify or not identify with those individuals. While their brains were scanned using functional MRI, the students were asked to predict the feelings and attitudes of the two targets in various situations. For example, they were questioned whether the target would enjoy having a flatmate from a different culture or think that European movies were better than their Hollywood counterparts. Finally, the students completed a version of the Implicit Association Test (see also this link), which was designed to index how strongly they automatically associate themselves with the liberal or conservative target (citation from NRN).

The brain responses differed significantly whether the subjects saw pictures of people with politically similar or dissimilar views as themselves. The ventral medial prefrontal cortex was more engaged when the students were mentalizing a target with similar political views, whereas the dorsal medial prefrontal cortex was more active when the students were considering a target with views on the different end of the political spectrum from their own.

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How the brain changes according to social relations: (A) A region of ventral mPFC showed greater activation during judgments of the target to whom participants considered themselves to be more similar. For participants who associated self with the liberal target (left set of bars), the response of the ventral mPFC was higher for liberal targets (middle, blue bar) than conservative targets (rightmost, red bar), and no difference was observed for judgments of self (leftmost, green bar) and the liberal target. In contrast, for participants who did not associate with the liberal target (right set of bars), the response of ventral mPFC was higher for conservative than liberal targets, and no difference was observed for judgments of self and the conservative target. (B) A region of dorsal mPFC showed the opposite pattern of results, that is, greater activation during judgments of the target from whom participants considered themselves to be dissimilar.

One may object and say that this dichotomy between democrats and liberals is an US-only study. Many other countries have a political system consisting of many political parties. But the human social world is filled with other examples that this study pertains to. Skin colour, for example, has alone led to prejudice and atrocities throughout history, and still occurs. Religious belief is another example.

Other differences are more covert. Think, for example, about the current World Championship in football. Football, or any team game, is a good example, because you find the same dichotomy between being “in” or “out” of a group as you find in the US study. You’re either with team A or B – even if you have no particular reason to favour one over the other (e.g. supporting Argentina while being a Norwegian). Strange as it is, football, being an innocent game of kicking and heading to a leather ball, is a prime example of how prejudice and in-out group social psychology comes to play. Maybe even more so. FIFA, the international football organization, has launched a campaign against racism. A recent article in the German Der Spiegel, however, has just demonstrated how “us against them” thinking leads to overgeneralizations and prejudice (the Spiegel article is now withdrawn, so see this).

In this way, the Neuron study hits the nail on it’s head by demonstrating that “even the brain” makes a difference between social group belonging. An entire field of social neuroscience is now emerging, even with an upcoming journal of its own! If one field in neuroscience is going to make the headlines, social neuroscience is bound to be it!

-Thomas

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prison.gifOur willingness to engage in punitive acts is a key part of our society. So claims a recent article in Science. Through the experiments of Milgram, Asch, Zimbardo, and Sherif psychologists have studied humans' engagement in costly social relationships with non-kin. With many of these experiments being done in students only, it has been hard to extrapolate the results to the entire population. Understanding different cultures through these experiments is even worse.

In this week's Science report, a team of scientists studied social interaction in different cultures, using three different social psychology experiments. The first was an ultimatum game:

(…) two anonymous players are allotted a sum of real money (the stake) in a one-shot interaction. The first player (player 1) can offer a portion of this sum to a second player, player 2 (offers were restricted to 10% increments of the stake). Player 2, before hearing the actual amount offered by player 1, must decide whether to accept or reject each of the possible offers, and these decisions are binding. If player 2 specified acceptance of the actual offer amount, then he or she receives the amount of the offer and player 1 receives the rest. If player 2 specified a rejection of the amount actually offered, both players receive zero. If people are motivated purely by self-interest, player 2s will always accept any positive offer; knowing this, player 1 should offer the smallest nonzero amount. Because this is a one-shot anonymous interaction, player 2's willingness to reject provides one measure of costly punishment, termed second-party punishment

The second game was a party punishing game (PDF):

(…) two players are allotted a sum of real money (the stake), and a third player gets one-half of this amount. Player 1 must decide how much of the stake to give to player 2 (who makes no decisions). Then, before hearing the actual amount player 1 allocated to player 2, player 3 has to decide whether to pay 10% of the stake (20% of his or her allocation) to punish player 1, causing player 1 to suffer a deduction of 30% of the stake from the amount kept. Player 3s punishment strategy is elicited for all possible offers by player 1. For example, suppose the stake is $100: if player 1 gives $10 to player 2 (and keeps $90) and player 3 wants to punish this offer amount, then player 1 takes home $60; player 2, $10; and player 3, $40. If player 3 had instead decided not to punish offers of 10%, then the take-home amounts would have been $90, $10, and $50, respectively. In this anonymous one-shot game, a purely self-interested player 3 would never pay to punish player 1. Knowing this, a self-interested player 1 should always offer zero to player 2. Thus, an individual's willingness to pay to punish provides a direct measure of the person's taste for a second type of costly punishment, third-party punishment.

The third game was a dictator game:

The [dictator game] is the same as the [ultimatum game] except that player 2 cannot reject. Player 1 merely dictates the portions of the stake received by himself or herself and player 2. In this one-shot anonymous game, a purely self-interested individual would offer zero; thus, offers in the [dictator game] provide a measure of a kind of behavioral altruism that is not directly linked to kinship, reciprocity, reputation, or the immediate threat of punishment.

Regardless of culture, the findings showed that the two measures of costly punishment produced an increasing proportion of individuals choosing to punish as offers approach zero. But there were substantial cultural differences also, especially in terms of people's overall willingness to punish unequal offers. In some cultures, offers as low as 10% were accepted without punishment, while other cultures were less inclined to reject such a deal.

How do these cultural differences come to be? Is there a relationship between people's willingness to share (altruism) and a culture's level of costly punishment? The researchers plotted the relationship between the minimal offers that cultural groups were to accept (x axis) and the mean offer from the dictator game (y axis):

punishment.gif
These results demonstrate that there is a positive relationship between the likelihood of accepting an offer (i.e. the level of willingness to punish small offers) and the willingness to share (i.e. altruism). In other words, in cultures where you are expected to share, you give more, even thought others have no way to threaten or punish you.

The researchers conclude:

These three results are consistent with recent evolutionary models of altruistic punishment. In particular, culture-gene coevolutionary models that combine strategies of cooperation and punishment predict that local learning dynamics generate between-group variation as different groups arrive at different "cultural" equilibria. These local learning dynamics create social environments that favor the genetic evolution of psychologies that predispose people to administer, anticipate, and avoid punishment (by learning local norms). Alternative explanations of the costly punishment and altruistic behavior observed in our experiments have not yet been formulated in a manner that can account for stable between-group variation or the positive covariation between altruism and punishment. Whether the co-evolution of cultural norms and genes or some other framework is ultimately correct, these results more sharply delineate the species-level patterns of social behavior that a successful theory of human cooperation must address.

-Thomas

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