Category: Neural plasticity

Two podcasts on neuroplasticity

I’ve got some longer things to come, but I wanted to draw attention to two podcasts on neuroplasticity that I found through Scientific American‘s Mind & Brain blog.

The first podcast is Brain Science Podcast #10 Neuroplasticity, a presentation structured around the book, Train Your Mind, Change Your Brain: How a New Science Reveals Our Extraordinary Potential to Transform Ourselves, by Sharon Begley. Begley is a science writer for The Wall Street Journal, and she builds the book around a discussion of the effects on the brain of meditation. As a summary of the book describes:

Is it really possible to change the structure and function of the brain, and in so doing alter how we think and feel? The answer is a resounding yes. In late 2004, leading Western scientists joined the Dalai Lama at his home in Dharamsala, India, to address this very question–and in the process brought about a revolution in our understanding of the human mind.

The second is an interview with Dr. Norman Doidge, author of The Brain that Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science. As Ginger Campbell, an emergency physician and the interviewer, describes:

We talk about the obstacles that delayed this important discovery. Dr. Doidge shares the stories of three of the scientists featured in his book: Paul Bach-y-Rita, Edward Taub, and VS Ramachandran. We also talked about how these discoveries might influence both patient care and future research.

I’m new to podcasts as I just bought myself a little iPod shuffle to listen to them on while I work out (and haven’t been doing too much of that with all the physical labour involved in farm-related projects, like building a sandstone wall and getting my veggie garden back under control after it was neglected for three weeks while traveling in the US). Ira Bashkow, an old friend from days with a dissertation reading group at the University of Chicago, suggested it as yet another way to cram information into our aging cortical regions, and I’m looking forward to trying.

‘How Your Mood Affects Your Health’

One of my preferred news compilation websites, Alternet.org, just published a piece, originally from the UK Independent (I believe), on the relation of emotions, personal interactions, and similar ‘moods’ on health. Anastasia Stephens, in the article, ‘How Your Mood Affects Your Health,’ runs through in very cursory fashion a whole host of research on the effects of things like laughing, stress, arguments, and crying on the human immune systems, healing, and the like.

The article has a lot of fun little research summaries, unfortunately, without links to the actual research reports or anything deeper about the studies. But there’s warnings about how arguing affects healing:

A half-hour argument with your lover can also slow your body’s ability to heal by at least a day. In couples who regularly argue, that healing time is doubled again. Researchers at Ohio State University discovered this by testing married couples with a suction device that created tiny blisters on their arm. When couples were then asked to talk about an area of disagreement that provoked strong emotions, the wounds took around 40 per cent longer to heal. This response, say researchers, was caused by a surge in cytokines — immune-molecules that trigger inflammation. Chronic high levels of these are linked to arthritis, diabetes, heart-disease and cancer.

Or another personal favorite:

Scientists at the University of California have discovered that laughter relaxes tense muscles, reduces production of stress-causing hormones, lowers blood pressure, and helps increase oxygen absorption in the blood. Cardiologists at the University of Maryland Medical Center found laughing can actually reduce the risk of heart attack by curbing unwanted stress, which can destroy the protective lining of blood vessels. A good giggle also burns calories since it’s possible to move 400 muscles of the body when laughing. Some researchers estimate that laughing 100 times offers an aerobic workout equivalent to 10 minutes on a rowing machine or 15 minutes on an exercise bike.

Continue reading “‘How Your Mood Affects Your Health’”

Keeping Brains Agile

This article from The New York Times, Mental Reserves Keep Brains Agile, illustrates a central point that Greg Downey and I want to make with neuroanthropology.  First, what you do with your brain, how that doing plays out in an environment, and how that playing out feeds back into the workings of your brain are a central part of what makes us human—and thus is a central part of how anthropology should approach the study of ourselves. 

What You Do: Having an active brain over your life course means that less neurons are likely to be lost and more connections actively generated and maintained.  The brain, like your muscles, is use-it-or-lose-it—we have the most neurons that we’ll ever have when we are children, and as children, we go through a lot of “selective pruning”.  That said, research has also shown the we keep producing new neurons throughout our lives, overturning a long-standing idea that we only get one set of neurons for life. 

Doing in Environment: As the article notes, “there is no ‘quick fix’ for the aging brain, and little evidence that any one supplement or program or piece of equipment can protect or enhance brain function — advertisements for products like ginkgo biloba to the contrary.”  Despite our wishes to the contrary, we need to do plenty of stuff in a challenging environment to maintain our cognitive reserves. 

Playing Back into the Brain: Both social relationships and physical activity make a difference to your brain.  Greg likes the physical side, so I will just highlight one quote here: “Long-term studies in other countries, including Sweden and China, have also found that continued social interactions helped protect against dementia. The more extensive an older person’s social network, the better the brain is likely to work, the research suggests.” 

That said, we can also draw two other lessons from the article.  First, as I pointed out briefly in my Introduction, we should avoid over-localizing function and pathology in any one area.  Brains are not as hard-wired as computers; people’s physiology is variable (including their brains).  We are soft wired, or “wet wired” to draw on the metaphor of a 1995 book.  As the article states, “up to two-thirds of people with autopsy findings of Alzheimer’s disease were cognitively intact when they died.” The second point, and a crucial one for neuroanthropology, is the implicit framing of the article.  The title reads “Mental Reserves Keep Brains Agile,” re-using a very old mind/body metaphor.  While Jane Brody speaks of social and physical activity, the main causal concepts are cognitive and physical: the cognitive reserve, the number of neurons present.  Subsequently, Brody has our social, physical and symbolic worlds revolve around the mind/body dichotomy.  Neuroanthropology needs to develop the research, the language, and the popular models to show what this article actually tells us: people’s social lives, from walking in malls to playing bridge, make a difference in the blood flow and neuronal connections of the brain.  Our lives play back into our brains.

The Brains of Conductors

The BBC News carried a story recently about research done on the brains of orchestra conductors and band leaders and how they responded to a complicated listening task. The researchers played two tones for the subjects very closely together, fractions of a second apart, and the subjects were asked to tell what order they were played in.

The most interesting finding was that all subjects, untrained controls and experienced conductors alike, demonstrated a decrease in activity on fMRI scans in the ‘visual areas’ (I presume the visual cortex) when asked to do this difficult listening task. As the BBC headline reads, ‘Brain “Closes Eyes” to Hear Music.’ The more difficult the researchers made the task, the more activity in the visual regions was decreased. As the BBC article puts it:

As the task was made harder and harder, the non-musicians carried on diverting more and more activity away from the visual parts of the brain to the auditory side, as they struggled to concentrate.

However, after a certain point, the conductors did not suppress their brains, suggesting that their years of training had provided a distinct advantage in the way their brains were organised.

The implications of this in terms of brain ‘enculturation’ are several, and I want to highlight a couple.

Firstly, the testing itself suggests that brain activity is task dependent, both in positive and negative terms. That is, ask the brain to do some things and not only do particular regions associated with the task get very active, but other, possibly competing or distracting neural activities, get suppressed. I’ve been thinking about the senses a fair bit lately (more on that soon), and this would seem to be one way in which the senses are not independent. Instead, the senses are linked together, even if it is in suppressive links, the heightened attention or concentration along one channel sometimes suppressing others. For culturally influenced patterns of sensing, it could mean that what we don’t sense is as important as what we do.

Second, these sorts of links between expertise and the effectiveness of sensing are variable phenomena, not necessarily existing at all levels of task demand. I find this interesting because it might not show up in every experiment, depending on the difficulty of the experimental task. In the case of the conductors, you don’t really notice the difference in their performance on the task until the difficulty is greatly increased.

Third, the ‘enculturation’ is very much a skill-dependent brain change. That is, it’s not a blanket, shared-by-all cultural trait, but one that’s only shared by a specialist group within a ‘culture.’ This makes more sense to me in a lot of ways because I work with elite athletics, but I suspect that many ways in which the brain is ‘encultured’ are not shared throughout what anthropologists typically think of as ‘cultures.’ Moreover, because the brain likely responds to similar demands by using similar mechanism, another elite practitioner of a parallel skill (like a musical leader in capoeira, the Afro-Brazilian martial art I’ve worked on) might have an ability that looked a bit like the conductors’. How these abilities differed then — not only in terms of their meaning, acquisition, and the like, but also in terms of the neurological dynamics — would be an interesting set of research questions.

One could write a lot more, but I’ll leave it at this for now.