Neuroplasticity on the radio
Posted by gregdowney on September 26, 2008
The original radio shows, audio recordings and transcripts (!) are available on the ABC All in the Mind website:
Part 1 of 2: The Power of Plasticity
Part 2 of 2 – The power of plasticity
See especially Part 2 as there are links to a host of other resources, such as the video of an interview Dr. Doidge did on ABC television while he was here in Australia, and discussions of the work of Prof. Paul Bach-y-Rita, one of the pioneers in work on neuroplasticity, including his research on technological prostheses for missing sensory information.
The material is great, and I’m nearly finished with Doidge’s book, but I still have several reservations about it even though I share the fascination with neuroplasticity and enthusiasm for Doidge’s work:
1) Plasticity, while it is clearly a crucial quality of the brain, is only one quality of a complex organ. Part of the reason for excitement about neuroplasticity is the artificial surprise that was generated because of long-held, erroneous beliefs about the immutability of the brain. In fact, the idea that the brain could not grow, change, adapt, or generate new cells is, in retrospect, pretty damn counter-intuitive and hard to believe. Most living organisms and organs are mutable, and from what we know about the brain’s performance–its ability to form new memories, learn, forget–we might logically conclude that the brain changes.
2) The evidence on plasticity from work like that of Prof. Edward Taub suggests that the brain is malleable, but that the amount of effort involved in changing the brain can be extraordinary. Taub’s work with stroke victims, like that of Bach-y-Rita, suggests that, in some cases, it can take thousands upon thousands of repetitions of basic actions to reshape neural sensitivity, if it is even possible. Sometimes the focus on ‘plasticity’ (rather than, say, long-term development) emphasizes the capacity to change over the severe demands that change actually makes on anyone seeking it. Doidge’s book is quite good on this in the long version, but I sometimes feel that brief discussions of neuroplasticity, especially in the popular press, oversell the malleability.
3) The focus on plasticity in cases of brain trauma tends to emphasize the most unusual cases — those where function is radically changed and severe deprivation or physiological alteration occurs. Although neuropathology has long offered one of the most important windows into brain function, these cases of brain trauma can be misleading for understanding non-pathological plasticity because plasticity is much harder when neural resources are already allocated. For example, brain reorganization following trauma may be more extensive than normally possible because a brain region may be deprived of input from its normal sensory area (such as after loss of a limb); such complete deprivation may be a precondition for large-scale change.
4) It seems to me that most of the ‘plasticity’ discussion is happening around, on the one hand, recovery from brain trauma, and, on the other hand, around self-help and adult populations (like those interested in leadership or Buddhist meditation). While these are both excellent areas to think about neuroplasticity, my opinion is that much of the story of neuroplasticity is in developmental settings, in the normal interactions and activities that occur during childhood. Again, Doidge discusses this in his book (as does John Medina in his book, Brain Rules), but this balanced focus tends to drop out in discussions in the media, where the focus is on adults, probably because the audience is adults.
5) Finally, to go back to the predominance of ‘plasticity’ in some discussions of the brain, I simply don’t think any one term is adequate to capture the basic ways in which the brain functions. For example, the discussion of plasticity may over-emphasize mutability and fail to reflect the degree to which brains develop regional specialization, for example, or reuse specialized regions in different functional networks. There are many stories to tell about the brain, and neuroplasticity is a pretty compelling one, but it’s not the whole story. Some of the self-help-ish discussion of neuroplasticity seems to suggest it’s the only story in town (of course, the same could be said about some evolutionary accounts of the brain).
Of course, the onus is not on those like Doidge to figure out all the stories to tell about the brain. In fact, his work should encourage all of us to raise our game, to make our own parts of the story more compelling and accessible. I know that I’m looking to his book as a role model for my own work on the motor enculturation of the brain; his work is admirable for its comprehensiveness, its accessibility, and its boldness. He’s left out plenty from his book, The Brain that Changes Itself, but that just means there’s ample room for others to contribute their pieces to the collective effort.
All this said, I still like Doidge’s book a lot, and I’m glad he’s doing interviews here in Australia. He’s really energized a lot of people here in Australia with his presentations and appearances in the media. And I still owe our readers a more complete review of his book — I haven’t forgotten.
Acknowledgements: Thanks to Stephanie West Allen for rousing me from my mid-semester collapse.