The brain's social network

Neuroscientists often attempt to attribute various behaviors and traits to certain regions of the brain. These findings make for neat science and great headlines, and while some of these results are little better than phrenology claims, many are highly reliable. The good ones are confirmed and replicated by multiple labs and substantiated using a variety of different methods, such as lesion, animal and human imaging models. For example, we know with relative certainty that much of the occipital lobe is in charge of processing visual information and that the hippocampus is heavily involved in transitioning from short term to long term memory. However, there is much in our behavior and our brains that we still do not understand, and it is highly tempting to simply assign certain sections of the brain to different traits, when in fact the underlying mechanisms are much more complicated. This tendency has become increasingly easy in the past decade with the rise of functional neuroimaging studies, where a region of the brain is seen to "light up" with activity when performing certain types of tasks. Voxel based morphometry (VBM) studies take these investigations a step further, looking at how gray matter volume in our brains correlates to different types of traits and behaviors. Two recent examples of VBM studies have investigated the neural correlates of social networking and extroversion, finding connections between amygdala size (among other regions) and social tendencies. The first study, out of University College London and published in the Proceedings of the Royal Society Biological Sciencesfound that people with more Facebook friends had increased gray matter volume in certain regions of the brain associated with social interactions. The authors of the study had hypothesized that the number of online friends one had could predict the relative brain size of regions important for social networking, particularly those involved in social cognition and mentalizing (the ability to recognize social cues and take another's perspective). These areas include the fronto-parietal cortical circuit, medial prefrontal cortex and amygdala. However these frontal cortical regions were not identified in the study, and instead the researchers discovered greater volume in the left middle temporal gyrus, right entorhinal cortex and right posterior superior temporal sulcus, as well as the amygdala to a lesser extent. These areas are implicated in social cognition, perception of movement and intention (both physical and social), and autobiographical and associative memory. Based on these findings, the authors speculate that individuals with greater brain volume in these regions are more adept at the skills needed to maintain online socio-personal connections, such as enhanced memory of face-name combinations and awareness of movement of individuals in social circles. However, of these regions only the amygdala was correlated with real life social interactions, and none of the other originally proposed areas were found to correlate with social network size.

The second study, just published this week in PLoS ONE, also reports that individuals who are more extroverted show increased volume in the amygdala, as well as in the orbitofrontal cortex (OFC). Researchers from the Netherlands administered the NEO Five Factor personality assessment to 65 individuals to subjectively measure extroversion and neuroticism levels. They also had participants undergo an MRI scan and used VBM analysis to measure the size of certain pre-determined regions of the brain against extroversion scores, including the amygdala, anterior cingulate cortex and OFC. Controlling for age, sex and total gray matter volume, researchers discovered that individuals who scored higher on the extroversion scale had significantly larger amygdala and orbitofrontal cortices, as well as finding a significant correlation between total gray matter volume and extroversion scores.

As stated above, the amygdala is one of the brain's emotional centers and is important in social interactions, both online and offline. It is crucially implicated in recognizing and processing positive and negative emotions, both in oneself and from the facial expressions of others. The OFC is also commonly associated with emotion regulation, as well as reward valuation and decision-making, mainly through its connections to limbic structures such as the amygdala, striatum and hypothalamus. However, it is not typically linked to social interactions, and the authors speculate that their findings are evidence of the amygdala and OFC's involvement in a greater sensitivity to positive experiences and social interactions, rather than interpersonal skills themselves.

While the findings from these two studies are intriguing and compliment one another nicely, caution must be taken in the interpretation placed on these results. Correlation analyses state only an association, not a causation, and, as recently brilliantly exhibited by Business Week, these connections can be highly questionable at times. This is particularly true of imaging studies, where investigators can potentially go fishing for regions to attribute their target behaviors to. Interpretations for correlations are quick to come by and rationales for connections in unexpected areas of the brain can be justified all too easily when a publication is on the line. A priori regions of interest are thus crucially important, providing groundings for current explorations based on previous studies and alternative research methods. I am in no way denouncing VBM studies and their value and viability generally, or these studies in particular, however I do caution about the interpretations that can be carelessly made with them. Additionally, in studies like these it is unknown whether the size of the regions predicts the behavior, or whether the brain adapts and grows to incorporate new connections based on the repetition and reinforcement of certain actions. In regards to the studies at hand, their confirmation of the amygdala's role in social interactions is highly supported, however it is unknown whether the increase in brain size is a predictor of social ability and network size, or whether practice of interpersonal skills helps to foster neurogenesis in these regions.

External (and internal) influences on decisions

We like to think that we are in control of our decisions. Yet evidence from various neuroeconomics and marketing studies have shown that many of the decisions we make in our day-to-day lives have less to do with our own personal choices than we would like to think, and that we are instead easily influenced by internal visceral states and external suggestions and primes. According to Martin Lindstrom, author of Brandwashed, many of the decisions we make, particularly in supermarkets and shopping situations, are often determined by manipulations made by marketing executives. Whole Foods and other supermarkets prime us to shop by arranging their stores, displays and prices in a certain way to make us perceive their products in a particular manner. They fill their stores with flowers, particularly right at the entrances, connoting freshness and evoking thoughts of newly picked produce right from the fields, when in fact much of these products have been sitting in warehouses for weeks. They also display items packed unnecessarily in ice or sprayed with water, again ensuring us of their freshness and vitality. These manipulations do little for the products themselves, but affect our perception of them and therefore our willingness to pay.

Bodily states can also alter our decision-making processes and preferences. Previous studies investigating the effect of visceral states on external decisions have shown that when in a condition of hunger, people have a greater desire not only for food but also for money. Fasted individuals also make riskier bets on a financial decision-making task involving lottery choices, opting for the riskier option significantly more often when fasted, and choosing the safer bet when full. This finding is supported by the animal literature, in which animals are more risk-averse when sated but risk-seeking when hungry. This is presumably an evolutionarily selected trait prompting exploration and risk-seeking when in states of hunger, which could potentially lead to the acquisition of new food sources.

A similar "state of urgency" might be expected to be seen in situations where people have to use the restroom, choosing an immediate satisfaction over long-term outcomes. However, in a clever study published last year in Psychological Science (and that recently won an Ig Noble award), individuals with a full bladder actually chose the delayed reward more often than instant gratification.

Led by Mirjam Tuk, researchers in the Netherlands had participants consume either 700 or 50 ml of water and then complete a delay discounting task. The discounting task involved binary decisions between two set options, one a small reward that participants could receive immediately and the other a reward of greater magnitude they would receive after a certain period of time. Participants also had to indicate how badly they needed to urinate, ranging from "very urgently" to "not urgently at all". Individuals who had consumed the larger amounts of water (and who reported a greater urgency to urinate) chose the delayed option more often than those who had received the smaller serving of water.

Researchers hypothesized that this was because bladder control involves deliberate inhibitory measures on the individual's part, which then promote inhibition and self-control in other aspects of life. The authors call this idea "inhibitory spill over", where conscious cognition in one aspect, influenced by a visceral state, leaks over into other domains. This contradicts other theories of self-control, which believe restraint to be a limited personal resource that can be depleted through instances of restriction in one area, thereby allowing lapses of control at other instances.

These studies provide evidence that we should be aware of our surroundings and current physical and mental states when making important decisions, particularly concerning money. Clearly we do not live or function in a vacuum, nor make our decisions in one, but being mindful of the subconscious influences that are upon us, both internally and externally, can help us to make better decisions with a clearer mind and less biased approach.

Leadership skills?

In our hyper-driven and competitive culture, gaining access to the elite "C-suite" of a corporation, and the money and power that engenders, is highly coveted. Ambition, drive, hard work, and a certain degree of ruthlessness are regarded as essential qualities in an aspiring leader and traits necessary for someone working his or her way to the top. However, two interesting commentaries on leadership and advancement in the professional world have recently questioned these qualities and brought to light their similarities to two seemingly very different life paths. In the first, journalist Jon Ronson makes the claim that top business leaders are four times more likely to have psychopathic tendencies than the normal population. In his new book The Psychopath Test, also brilliantly re-told on This American Life, he claims that 4% of business leaders demonstrate psychopathic tendencies, as compared to 1% of the normal population. He attributes this to a significantly less active amygdala, the region of the brain associated with fear and emotion. In psychopaths, or potentially CEOs, fear and empathy are diminished, enabling them to act selfishly or in the spirit of Machiavelli, if you will. Abnormal amygdala responses allow them to take risks and ruthless measures to get ahead and leave them disinhibited from the feelings of guilt, apprehension, or remorse that most of us would feel after firing employees or conning someone out of their money.

In his book he interviews Al Dunlap, the CEO of Sunbeam toasters and a man known for his cut-throatness and proclivity for firing people with glee. Ronson informally administers the classic PCL-R (Psychopath Checklist-Revised) to Dunlap, on which he scores higher than normal, though not high enough to register as a true psychopath. However, Dunlap does manages to turn nearly every item he answers affirmatively to into a positive quality for business. For instance, reinterpreting "a grandiose sense of self-worth" as "believing in yourself", and "lack of remorse" as "freeing yourself up to move forward and achieve more".

While the claim that most CEOs are secret psychopaths may not hold true, a second theory does carry more weight. Originally raised in neuroscientist Dr. David Linden's new book on pleasure, The Compass of Pleasure: How Our Brains Make Fatty Foods, Orgasm, Exercise, Marijuana, Generosity, Vodka, Learning, and Gambling Feel So Good, and reiterated recently in an opinion piece for the New York Times, Linden makes the comparison between addictive personality traits and leadership skills. He cites compulsivity, risk taking, and a depletion in pleasure as tendencies that could be utilized to facilitate perfectionism, a push towards new financial ventures, and an unwillingness to settle in business. However these traits can easily manifest disadvantageously in society's leaders, the most obvious example being the poor risky decisions made in the financial and political sectors that resulted in the global recession.

Additionally, it is not only these personality traits that drug users and innovative leaders have in common. Paradoxically, many of the creative geniuses and political and financial authorities of our time have struggled with drug or alcohol abuse at some point in their careers. Indeed, it would be surprising for these men and women to apply their sensation seeking tendencies towards only one aspect of their lives, and thus it is not uncommon for influential leaders and those in power to abuse drugs or alcohol. A new book on cocaine use, The Anatomy of Addiction by Dr. Howard Markel, has brought these tendencies to light using Sigmund Freud, the father of psychoanalysis, as a prime example. In addition to Freud, Linden also lists Winston Churchill, Aldous Huxley, and Alexander the Great, as well as countless others, as examples of leaders who have struggled with addiction. However, it is important to note that most of these writers, CEOs, dignitaries, and geniuses were not on drugs at the moment of their breakthroughs.

I am not one to criticize drug taking or experimentation, but I am against the romanticization of these habits that can so easily become dangerous compulsions (compulsivity is clinically referred to as the persistence of a behavior despite negative consequences). Light experimentation with mind-altering substances is often cited as having provided inspiration and cognitive expansion perhaps not otherwise possible in our daily world. However, truly addictive drugs such as cocaine or opiates rarely provide these experiences without some potentially devastating long-term consequences. It is possible to maintain a recreational relationship with some of these substances, however it is a slippery slope that should be rappelled with extreme caution. The personality traits of curiosity and the desire for exploration, both personal and intellectual, do seem to foster innovation and creativity, and compulsivity can be analogous to perfectionism or a relentless drive for success. However, compulsivity can also lead an individual from exploratory recreational use to drug abuse and dependence, and it is important to keep in mind that those individuals who created corporate, creative or intellectual masterpieces while on drugs may have done so in spite of, not because of their addictions.

(Thanks to Tanner Brown for the Sam Harris link)

Does the internet control our minds?

As some of you may have noticed, I get a lot of my ideas for posts from the New York Times. I like to think that it is a relatively unbiased source of information, and I believe that it has several interesting news articles or opinion pieces every week. However, even my beloved NYT is guilty of a potentially dangerous trend towards self-fulfilling bias, regurgitating back opinions to me that I already agree with and information I know to be true. (Though in their defense they did publish a great op-ed piece recently calling this phenomenon to our attention.) Everyone is guilty of cognitive bias and selective attention. Quite simply, we prefer to read things that confirm what we already believe. Both the sources that we choose to consume, as well as the information we retain from these sources, will more than likely further cement our own original views. It is very difficult to change one's opinion on an important topic, not only because we rarely seek out conflicting beliefs, but because even when we do we are prone to misinterpret, disregard or even forget anything that disagrees with us. While ideally we would all make unbiased decisions about the content and media we consume, clearly this is not the case; it is no big secret that conservatives watch Fox News while liberals prefer MSNBC or the Daily Show. However, nowadays search engines and online news sources are further filtering down the selection of content for us to consume by crafting search and recommendation results based on previous articles or links selected. With these algorithms, even if you wanted to branch out from your usual media content you might be unable to, or it would at least involve more in-depth clicking or search terms.

We covet and praise the use of personalized prediction models on sites like Netflix and to recommend music and movies similar to what we already know and like.  But when the decisions made by mathematics and computers affect not only our artistic tastes but also our world views and political opinions a dangerous line begins to blur. Nowadays, it is no longer the government censoring information and ideas, it is our brains and the information readily available to us.

This also brings up the scary question of how reliant we actually are on the internet and technology at large, not only for our news and celebrity gossip, but more importantly for the ability to work, communicate and connect with people personally and professionally. In a rather bizarre survey conducted by the McCann WorldGroup, 53% of youth would rather sacrifice their sense of smell than give up their computer or smart phone. To put it bluntly, our society is obsessed with technology; we have become addicted to the internet. As someone who researches drug addiction, I do not use this term lightly, but really the comparisons are telling. Escalation of use, inability to cut back when attempted, a feeling of urgency or craving to get online after prolonged periods of abstinence, persisted use even in the face of negative consequences, not to mention the surge in rewarding dopamine we experience when our iPhones "ping" with a new email or text message.

In the spirit of true Pavlovian conditioning, that noise, that pervasive ping, has taken on the ability to arouse us in the way that a natural reward would. It has become associated with the news that someone has reached out and contacted us, and thus has achieved the same rewarding significance. The excitement or joy you get when you hear that ping and anticipate opening an email (is it a letter from a friend? a Facebook invite? or the ever disappointing listserv update), increases your arousal and causes dopamine to be released into the basal ganglia (particularly the nucleus accumbens), just as seeing a friend or being invited to a party would in real life. Over time, this ping has become associated with social interaction, and the feeling of reward this evokes has gradually been transferred from the email content to the cue itself. So now this ping, whether it's from your own phone or the hundreds of others like it, creates this same state of arousal and surge of dopamine that anticipation of intimate interaction in real life might elicit. If you're like me, you are also hyper-sensitive to this sound, assuming you've heard it in a song or ambient noise. Greater attention is allocated to perceiving the ping from the cacophony of sounds we are inundated with every day, just as a drug user has greater vigilance to perceive cues associated with drugs and their related paraphernalia from a vast array of sensory stimuli.

The internet is an invaluable tool in our arsenal and without a doubt no one would advocate returning to a time before it. However, we should keep in mind just how much time and energy we spend on it, and how reliant we have become. The uprisings in the Middle East and Northern Africa and the resulting internet shut downs protesters in Egypt and Syria were subjected to should remind us that the internet is not necessarily a constant, and perhaps it is important to keep our reliance on it, both personally and intellectually, in check.

(Thanks to Emily Barnet for the McCann survey.)

Pursuing happiness

In honor of the 4th of July and in the spirit of the Declaration of Independence, The Atlantic published a nice piece on the "Pursuit of Happiness" this week, specifically on how our community and environment can shape our mood and mindset, and how local governments are initiating public service projects to aid in our "psychological well-being". However, a study published in the Journal of Human Genetics last month by behavioral economists at the London School of Economics suggests that it is not external factors, but rather our genes and neurotransmitters (most notably serotonin) that determine how happy we are. Serotonin has been linked to happiness and empathy, and a depletion of it is often seen in patients with depression. Many common antidepressants work by elevating levels of serotonin in the brain, such as SSRIs (selective serotonin reuptake inhibitors) which prevent the retraction of serotonin back into the cell after it has been released. This recycling of serotonin occurs naturally in the brain, with neurotransmitter transporters binding to the chemical in the synapse, taking the serotonin back up into the cell and enabling it to be released again. The serotonin transporter gene 5-HTT is involved in the expression of the proteins that form these transporters and has two different forms it can take, a long or a short version. The long allele of 5-HTT results in more transporters being expressed, and paradoxically researchers have recently discovered that individuals who carry both the long versions of the gene are significantly more likely to report higher levels of subjective well-being than those who inherited both short versions of the allele. In the study by Dr. Jan-Emmanuel De Neve, 69% of those with the long version rated themselves as either satisfied or very satisfied with their lives, as opposed to only 38% of people with the short version. While this is contradictory to the theory behind SSRIs, which prevent this recycling and thus enable higher levels of serotonin to be present in the synapses, the greater number of transporters in the long allele population permits faster turn-over, facilitating greater release and higher stable levels in the brain.

On the other end of the spectrum, individuals with short alleles are known to have decreased brain density in the amygdala and limbic circuitry, areas implicated in emotion regulation and fear responses, impairing their perception and reaction to emotional stimuli. Those with short alleles have a higher risk of depression, although this association is somewhat tenuous as the 5-HTT gene directly only accounts for 10% of an individual's susceptibility to anxiety or depression. Most likely, it is a gene-environment interaction that determine's an individual's likelihood for developing depression, as individuals with short alleles are more prone to react poorly or with greater anxiety to bad news.

Thus, returning to The Atlantic article, to what extent can our environment really foster a positive affect, and do things like city planning, determining traffic flow or green spaces, really influence our overall levels of happiness? How much do the little things in our environment matter? Sure it's unpleasant to sit in traffic and much more agreeable to eat lunch under a tree, but in the greater manifestation of mood do these things affect us on such a fundamental level? After the immediate physical or aesthetic enjoyment, are there pervasive lingering effects? Surely it is more the people we surround ourselves with and our own internal perception of events that determines our mood. How much of an effect do we have on our own happiness and how much is determined by our surroundings? What truly makes us happy?

The neuronal defense

There's been a lot of discussion recently about structural and hormonal changes in the brain being to blame for misbehavior, whether it's a philandering husband (or senator) or a psychopath. To some extent these are valid arguments; higher testosterone levels have been linked to sensation seeking and greater sexual desire, and abnormalities in the limbic system, particularly the amygdala which processes fear and emotion, and the frontal cortex, which is in charge of inhibition and rational thought, are often seen in persons who commit crimes. However, to use these structural phenomena as excuses or arguments as in, "My brain made me do it", is the same as proclaiming, "Yes, I did this". Obviously there are times of rare and extenuating circumstances when an individual's actions are truly no longer under their own control, such as in the case of a tumor in the frontal lobe changing the temperament and personality of an individual. However, for the vast majority of individuals, we are our brains, and saying you are "pre-wired" to cheat or fight or steal is not an excuse. If anything, it is a greater indication for potential recidivism and an added incentive for either punishment or preventative measures. Excess testosterone is not a pathology like schizophrenia or mental retardation, which can be used as defenses in court for criminal actions. Additionally, if you blame chemicals like testosterone or a lack of oxytocin for misbehavior, then what is to stop us from exonerating people who commit crimes because they are on a synthetic drug, like crack cocaine or PCP? And, seeing as how presumably not all men with increased testosterone cheat and not all individuals with abnormal amygdalas commit crimes or become sociopaths, it is difficult to argue that your brain and neurotransmitters make you do something when these same conditions do not compel another to a similar path.

David Eagleman's article in The Atlantic is a particularly insightful and eloquent investigation into both sides of this issue, which I highly recommend. Instead of focusing on the question of guilt and the implications that recent advances in neuroscience and neuroimaging have on culpability, Eagleman wisely shifts his focus to sentencing and the more constructive ways to incorporate our new crude knowledge of the brain into the justice system. He suggests concentrating on the potential for recidivism and reform when determining sentencing, instead of retribution. Drug courts have already started shifting towards this perspective, supported by the recent initiative by the Global Commission on Drug Policy, marking the 40 year anniversary of the War on Drugs. Not only is it important to help drug users receive treatment instead of punishment, our economy simply can not accommodate the deluge of drug related crimes into the penal system, most strikingly demonstrated by the decision in California this month to release 3,000 prisoners before their sentences were up due to a lack of resources.

Child criminal courts have also dealt with this issue of neuroanatomical defenses for quite some time, as it is widely established that the frontal cortex is the last area of the brain to finish developing, not reaching full maturation until the mid-20s. Countless juvenile defenders have used this argument to insist that their client was not a rational individual at the time of their crime, and therefore should not be held accountable for their impulsive and illegal actions. While this is certainly a valid point, and one that is typically taken into consideration when distributing sentencing, with prolonged punishments thought to be excessive and insensitive to changes the individual will undergo in the next 5-10 years, it is important to bear in mind that not all 15 year-olds commit crimes. Therefore, this universal neural stage of adolescence that we all pass through is not necessarily a credible criminal defense, as otherwise all teenagers would be running rampant and wreaking even more havoc than they already do. Also, there are innumerable studies citing the increased risk of offense in impoverished or violent areas, yet this is not used as an excuse for a crime when poor behavior is conducted. It is absolutely a reason to reform the social system that creates these pockets of poverty and risk, but it does not compel juries to acquit defenders of their crimes simply because of the neighborhood they were raised in.

At some point, people must take responsibility for their actions and face up to the consequences, not blaming an integral part of them for going rogue and acting out of character. When you make a decision it is your brain acting and your neurons firing; you can not excuse an action because you claim you could not control these impulses. There is no outside force urging you to act or not, for that is your own will being administered and carried out. Eagleman's idea of a spectrum of culpability is a sensible one that I support, and I fully agree that in the vast majority of offenses reform and rehabilitation should be the goal, rather than retribution, however this still leaves the topic rife with ambiguity for where do you draw the line? At what point we will stand up and take responsibility for our own actions?

(Thanks to Tristan Smith for The Atlantic article.)