Culture on the Teen Brain

Harvard Magazine has a short piece this month on the work of neurologists Frances Jensen and David Urion to popularize information about the “teen brain” to audiences. As Jensen says, “This is the first generation of teenagers that has access to this information, and they need to understand some of their vulnerabilities.”

That information? That, given the way their brain is maturing (both fast-growing synapses and other sections relatively unconnected), adolescents are more “easily influenced by their environment and more prone to impulsive behavior.” As expected, there follows a typical line of parental angst: the sexes are different, drugs harm brains, kids need to sleep and get exercise, they are suffering from sensory overload from all the new technology. By implication, it is all due to being in “this paradoxical period in brain development.”

Certainly there are some intriguing results about brain development in adolescent related to differential brain maturation, developmental plasticity, and the like. Some early research based on longitudinal research is summarized here in an NIMH press release, which concludes in better fashion: “the teenage brain is a very complicated and dynamic arena, one that is not easily understood,” whether for parents or for researchers. But as I covered earlier in a post on emotion and decision making, teenagers can actually be seen as rather good decision makers, just focused on differential goals and contexts than most adults.

And come on, teenagers are overwhelmed by information and multitasking in today’s “brave new world”? I wish I had half the skills that my incoming freshmen display in this arena-I’m the one who doesn’t quite know how to handle the sensory overload…

Another graphic accompanies the Harvard article (only in the pdf though), an illustration by Leslie Cober-Gentry. For me, it shows the enormous gap between the brain imaging graphic and this more cultural graphic. As with all imaging research, there can only be correlations between level of activity and a particular task at hand. But that equation leaves out all the other important correlations that exists between, say, being impulsive and a particular environmental context. The juxtaposition of the two images capture perfectly what Urion and Jensen do, project our everyday life and concerns onto our newest explanatory cause-the brain.

Cultural Neuroscience

Shihui Han and Georg Northoff have just published Culture-Sensitive Neural Substrates of Human Cognition: A Transcultural Neuroimaging Approach. This article will prove foundational for “cultural neuroscience,” a term Han & Northoff use near the end of the article. I highly recommend that everyone read the full version (pdf), but will outline and comment on it here.

In this Perspectives piece in Nature Neuroscience Reviews, Han and Northoff review the evidence on how culture influences neural mechanisms, highlight the need to integrate social neuroscience and cultural cognition research, argue for transcultural neuroimaging as an effective method for cultural neuroscience, and lay out implications for the future of this emerging field.

But if you don’t take my word for it, here’s their abstract:

Our brains and minds are shaped by our experiences, which mainly occur in the context of the culture in which we develop and live. Although psychologists have provided abundant evidence for diversity of human cognition and behaviour across cultures, the question of whether the neural correlates of human cognition are also culture-dependent is often not considered by neuroscientists. However, recent transcultural neuroimaging studies have demonstrated that one’s cultural background can influence the neural activity that underlies both high- and low-level cognitive functions. The findings provide a novel approach by which to distinguish culture-sensitive from culture-invariant neural mechanisms of human cognition.

Cultural Effects on Cognition

Han and Northoff systematically cover research on “cultural effects on cognition,” including perceptual processing, attentional modulation, language and music, and number representation and mental calculation. Their Figure 1, presented below, summarizes research on culture and attention, highlighting context-dependent differences in attention between Americans and East Asians.

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Integrative Neuroscience

Integrative Neuroscience is a multidisciplinary endeavour to build unified models of the brain from the various disciplines within the neurosciences. It is an effort to break down the boundaries and encourage a freer exchange of information across disciplines and scales. The highly jargonised world of science can often mean that findings from one area of science are completely incomprehensible to another. However, it is crucial that efforts are made to consolidate the knowledge from various streams within the brain sciences. From the micro-scale findings to the macro-scale findings, integrative neuroscience deeply informs clinical research and practice. It means that when a patient is diagnosed with a brain disease, we can typify the genetic, neurological, social and environmental influences on his/her condition. It is a form of diagnosis and treatment that has never existed before.

While two brains may perform the same function, the way in which they do it is never the same. Statistically it is almost impossible for the underlying connections of any two brains to be exactly the same. What does this mean? Well, it means that no two brains react to the same actions or events in the same way. You may jump out from a hiding place and scream “boo” at your best friend who freezes in fright, while someone else might react more aggressively. Similarly, if you administer a neuroactive drug to two different people, the effects can be dramatically different. That is why some patients who are prescribed medication for a brain disorder may get better, while other patients may have little or no reaction to the same drug. You will often find that Psychiatrists, neurologists and other clinicians will personalise treatments for patients. Whether the treatment is behavioural, cognitive or pharmacological, nearly all treatments must be personalized. These treatments can only become better when more people share their experience and knowledge of personalized medicine. So what is your story?

LINKS:

Integrative Neuroscience Links         

Journal of Integrative Neuroscience   

Brain Dynamics Centre                                                

Integrative Neuroscience Facility                                             

Centre for Integrative Neuroscience and Neuroengineering

Brainnet

Brain Resource Company

 

 

                          

Personalized Medicine

There is a large amount of variation in the manifestation of brain disease. There is also a large amount of variation in the response to treatment. Often patients are prescribed drugs on a trial-and-error basis until the right drug is found. This situation, multiplied across many cases, can lead to over-servicing, inefficiency and high expenses in the healthcare industry—not to mention the stress this places on individuals, their families and friends. Integrated Neuroscience could be heading towards an answer in dealing with the large amount of variation in the symptoms, diagnosis and treatment of brain disorders. This answer is called ‘Personalized Medicine’. A Brain-related Personalized Medicine approach matches genetic markers (gene-related information) with neuromarkers (brain-related information).

The brain is arguably the most complex organ of the body. It is subject to biological and environmental influences as well as the personal life history and experiences of individuals. A Personalized Medicine approach hopes to match treatment programs with the biological and psychological profile of each individual. With recent advances in biomedical science, this treatment ethic may be more realistic than ever before. Neurogenomics has gone some way in elucidating a vast number of genes that play a role in various brain disorders. However, a genetic approach alone is insufficient to diagnose and treat the development of brain disease. The combination of both genetic-markers and neuro- markers is crucial in the ultimate success of any one particular treatment.

Neuromarkers include observations of brain structure (using MRI), imaging of brain function (EEG, ERP, MEG, fMRI and PET) and psychological tests measuring social, emotional and cognitive performance. Further research is needed towards the orientation of Brain-related Personalized Medicine. Research will need to establish the links between genetic-markers and neuromarkers (genomic-neuromarkers) for use in diagnostics, drug development, treatment prediction and treatment efficacy monitoring. From here, clinicians will be able to better match the appropriate treatment for each patient according to the developmental stage of their disorder. The outcomes may even extend further to a preventative medicine that contributes to disability management, harm minimization, psychosocial and quality of life recovery.

Links:

The Biomarkers Consortium

The Personalized Medicine Coalition

Personalized Medicine Coalition

The Food and Drug Administration

The Royal Society

Dan Segal Report

The Brain Resource Company

 

The Brain Resource International Database is one methodology used to acquire genomic-neuromarker profiles. The Database pools data about genetic make-up, brain structure and function, cognition and psychology as well as the life history of participants.

These ‘genomic-neuromarkers’ will be incorporated in the next version of the DSM (DSM V) expected to be released in 2011.

Cabbies’ brains

The BBC has a nice piece covering the continuing research of Prof. Eleanor Maguire (Wellcome Institute of Neurology, University College London) on the distinctive development of the hippocampus in the brains of London taxi drivers: Taxi drivers’ brains ‘grow’ on the job. Prof. Maguire’s research in this area is pretty extensive (see publication list). She’s found a great naturally occurring experiment in the brains of cabbies who have to navigate London’s notoriously byzantine downtown streets.

As the BBC report describes, driving a cab in London is difficult and demands a well-developed knowledge of urban geography:

In order to drive a traditional black cab in London drivers have to gain “the knowledge” – an intimate acquaintance with the myriad of streets in a six-mile radius of Charing Cross.

It can take around three years of hard training, and three-quarters of those who embark on the course drop out, according to Malcolm Linskey, manager of London taxi school Knowledge Point. “There are 400 prescribed runs which you can be examined on but in reality, you can be asked to join any two points,” he told BBC News Online.

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Cultural Aspects of PTSD, Part II: Narrative and Healing

Bremner et al. 2000.  MRI showing decreased hippocampal volume in Vietnam veterans diagnosed with PTSD.

Narrative and memory are interwoven in our consciousness, and thus explorations into trauma from both humanities and social science perspectives almost invariably discuss narrative in one form or another. An ongoing debate within psychological research, for example, ponders whether the coherence of trauma stories is correlated to the amount of emotional distress associated with a given traumatic memory. It is hypothesized that the greater the distress, the less organized the narrative. If this were the case, we might expect that the coherence with which an individual is able to talk about the trauma would increase as the memory is processed and resolved, a finding for which we have some evidence.

We do know – when it comes to Post-Traumatic Stress Disorder (PTSD) – that narrative matters. As I wrote in an earlier post, the most effective therapies yet proven for reducing PTSD symptoms are the exposure therapies, particularly Prolonged Exposure (PE) therapy. These therapies are more effective for reducing the full range of PTSD symptoms than any pharmaceutical yet identified. And the crux of these therapies rests on telling the story of the trauma, sometimes over and over again. This simple practice, this process of speaking, has been reliably demonstrated to result in an improvement of PTSD symptoms for many patients.

But for all its clinical benefit, this extraordinary observation tells us very little about the mechanisms of psychic healing after trauma. Instead, it points to a growing body of evidence that suggests it is not just narrative that matters in PTSD, but, more intriguingly, that it is the type of narrative that matters. Unstructured psychodynamic therapies, for example, have not been demonstrated to lessen the severity of PTSD, even among patients who continue in therapy for years. And yet certain ways of narrating memory do make a difference, and this phenomenon once again points to a role for anthropologists and other culturally-minded researchers in exploring the cultural-emotional-physiological-environmental interactions at play in post-traumatic processing.

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Wired for Belief?

The Pew Forum on Religion and Public Life brought together the neuroscientist Andrew Newberg and the journalist David Brooks (yes, of neural buddhists fame) for joint presentations back in May, followed by a round-table Q&A discussion with a prominent group of journalists. The transcript of the entire event is now up, and that includes the audio as well as plenty more of the pretty brain graphics that you see here and some good event photos.

The presentations and discussions covered a wide range of topics, ably summarized and linked at the beginning of the transcript, including the physiology of beliefs and brains in meditation and prayer from Newberg and the revolution in brain research and neuroscience and soft-core Buddhism from Brooks. The discussion was also wide-ranging, going over issues such as Is religious Darwinism valid? and Brain physiology in party politics. As befits a Pew gathering, there is a considerable amount of attention focused on religion, atheism, and the like.

Newberg covers a lot of his take on the biology of belief as well as imaging research he has done on people praying or meditating. Here’s an excerpt on belief:

So our brain is trying to put together a construction of our reality, a perspective on that reality, which we rely on heavily for our survival, for figuring out how to behave and how to act and how to vote. But again, the brain is filling in a lot of gaps and helping us think certain things that may or may not really be there… So what are beliefs? Again, I apologize, but I always come at this from a scientific perspective. I am defining beliefs biologically and psychologically as any perception, cognition, emotion, or memory that a person consciously or unconsciously assumes to be true. The reasons I define beliefs in this way are several-fold. One is that we can begin to look at the various components that make up our beliefs. We can talk about our perceptions. We can talk about our cognitive processes. We can talk about how our emotions affect our beliefs. And we can also look at how they ultimately affect us. Are we aware of the beliefs we hold? Or are they unconscious? And which ones are unconscious and which ones are conscious?


And an excerpt connecting belief to the practice of religion.

The practices and rituals that exist within both religious and non-religious groups become a strong and powerful way to write these ideas into our brain. Again, go back to the idea that the neurons that fire together, wire together. The more you focus on a particular idea, whether it is political or religious or athletic, the more that gets written down into your brain and the more that becomes your reality. So that is why when you go to a church or a synagogue or a mosque, and they repeat the same stories, and you celebrate the same holidays that reinforce that, you do the prayers, and you say these things over and over again, those are the neural connections that get stimulated and strengthened. That is a strong part of why religion and spirituality make use of various practices valuable for writing those beliefs strongly into who you are.

Brooks aims to place these sorts of ideas into a social and cultural context.

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Lessons from sarcasm (so useful…)

The New York Times ran a story on brain imaging studies of sarcasm, The Science of Sarcasm (Not That You Care), by Dan Hurley. That’s right — that favourite rhetorical tool of the snarky adolescent has been subjected to brain imaging studies. The Pearson Assessment video — of an actor delivering the same lines twice, once sincerely, and once dripping sarcasm — is fun. I found myself thinking that I could have been MORE sarcastic.

Hurley, the author of the NYTimes article, does a pretty good job of explaining things, although I think that the idea that perceiving sarcasm requires a ‘theory of mind,’ alluded to in the article, is a bit of a problem — but I have that issue with a lot of the ‘theory of mind’ material because I think it ‘over-cognizes’ social perception (that’s my own issue, so I won’t dwell on it). Hurley discusses the research of Katherine P. Rankin, using MRI scans and the Awareness of Social Inference Test, or Tasit. I have looked on the website for the Memory and Aging Center of UCSF, and through PubMed and EurekAlert, but I can’t find the original report on this research (please post a comment if you know where it is).

“I was testing people’s ability to detect sarcasm based entirely on paralinguistic cues, the manner of expression,” Dr. Rankin said. What seems particularly interesting is that the part of the brain which seemed to be linked to sarcasm — damage to it by dementia impeded the ability to recognize sarcasm — was in the right hemisphere, not usually associated with language or social interaction (which are generally associated with the left hemisphere). Instead, sarcasm seemed to require activity in ‘a part of the right hemisphere previously identified as important only to detecting contextual background changes in visual tests.’

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Wired on imaging ‘neurohype’

Wired magazine has a good piece on recent attempts to market neuroimaging services to individual consumers, Brain Scans as Mind Readers? Don’t Believe the Hype, by psychiatrist Daniel Carlat. Vaughan at Mind Hacks has a good discussion of the piece, Don’t believe the neurohype (thanks to Vaughan, also, for alerting me to the original piece). The Wired article, in addition to sharing Carlat’s adventures with the pay-per-scan industry, has a nice table of ‘neurologisms’ as well to help out the less-neurohip among us (myself included).

(I was a bit chastened by the line: ‘Add the prefix neuro to a discipline and you get a new field with instant cred. But the science can be less than compelling.’ uhhh… we at Neuroanthropology hope that our readers will judge us by our results; we plan to earn our ‘cred.’)

As Vaughan discusses, some people have a financial interest in over-interpreting brain scans and exaggerating what they can do:

Scientists and responsible clinicians will know about these shortcomings and make sure they don’t oversell their findings, but commercial companies are not selling you the data, they’re selling you a way of make you feel better about your insecurities, whether they be commercial concerns or health worries.

All I would add to this is ‘most‘ scientists know about these shortcoming and don’t paper over them when describing their research (and we’re happy to heap scorn on those who don’t have the proper humility).

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