Neuroplasticity with Michael Merzenich

A friend and fellow PT, Jon Newman, recently sent me a link to a TED video released for public viewing only in April, it seems - Michael Merzenich on rewiring the brain. If you have ever wondered what neuroplasticity is, check this out. It runs about 23 minutes and I guarantee you'll come away with a deeper grasp of what the brain is and does.

Here is an excerpt I thought was particularly interesting:

"Now, one of the characteristics of this change process is that information is always related to other inputs or other information that's occurring in immediate time, in context. And that's because the brain is constructing representations of things that are correlated in little moments of time, and that relate to one another in little moments of successive time. The brain is recording all information and driving all change in temporal context.

Now, overwhelmingly, the most powerful context that occurred in your brain, is "you". Billions of events occurred in history that are related in time to your "self" as the receiver, your "self" as the actor, your "self" as the thinker, your "self" as the mover.

Billions of times, little pieces of sensation have come in from the surface of your body, that are always associated with "you," the receiver, and result in the embodiment of "you". "You" are constructed. Your "self" is constructed from these billions of events; it's constructed, it's created in your brain and it's created in the brain by physical change. This is the marvelously constructed thing that results in individual form, because each one of us has vastly different histories, and vastly different experiences, that drive into us this marvelous differentiation of self, of personhood."

I love this video. It makes me glad I picked the sort of work I did. I quite like the idea that when I put my hands on someone else, I'm helping them learn more about who they are, helping that brain add to its construction of "self" outside of a pain construction (if I'm careful, and I am). I like that I'm adding more "little pieces of sensation" to their temporally correlated process of embodied self, minus nociceptive input, i.e., more "danger" signals. Yeah, I can live with that.

I also like the idea that I learn more about/add to my own self-construct at the same time, as "little pieces of sensation" from my own skin (on my hands) enters my brain and is temporally correlated to what is already in there.

What is already in there? Circuitry routes, billions of neurons, receptor sites on them (lots and lots of receptors that can change to different ones, alter what they are sensitive to, thanks to "synaptic plasticity") and transmitters. There are convergence zones and arborizations, ascending and descending fibers, switchback and feed forward stations, and lots of somatotopic representational areas (brain maps of body parts). There is brain behaviour, and parts or areas that light up for pain as well as for other functions on fMRI, a vastly complex ecosystem, embedded within another outer ecosystem called the "body," with which it is completely integrated, both of which must exist co-mingled and learn to help each other within the greater outer planetary ecosystem, via a construct called "self."


Additional Reading

1. Michael Merzenich's TED bio
2. A page from my website, About Pain


Older blogposts on Neuroplasticity

1. Neuroplasticity (Dec 11, 2007)
2. Learning (Dec 12, 2007)
3. History of Neuroplasticity (Dec 12/2007)
4. Paradigm (Dec 16, 2007)
5. About mirror therapy (Dec 16, 2007)
6. Get your game on, ease your pain (Dec 17, 2007)
7. The devil is in the details (Dec 18, 2007)
8. A few types of Learning (Dec 18, 2007)
9. Cart ruts: More about UN-doing something (Dec 29, 2007)
10. And it's about brain parts: like hippocampus (Dec 30, 2007)
11. Function only (January 15 2008)
12. Smart prosthetics, smart nerves, smart brains (February 10, 2008)
13. Nervous System Basics VIII: PLASTICITY (May 10, 2008)
14. More about neurogenesis (June 7, 2008)
15. "Dialogues in Clinical Neuroscience" online (August 23, 2008)

More about neurogenesis

There are some other posts here that include the topic of neurogenesis:
1. History of Neuroplasticity
2. And it's about brain parts: like hippocampus
3. Nervous Systems Basics VIII: PLASTICITY

Here is a new study on the matter; Spatial Relational Memory Requires Hippocampal Adult Neurogenesis.

Abstract: The dentate gyrus of the hippocampus is one of the few regions of the mammalian brain where new neurons are generated throughout adulthood. This adult neurogenesis has been proposed as a novel mechanism that mediates spatial memory. However, data showing a causal relationship between neurogenesis and spatial memory are controversial. Here, we developed an inducible transgenic strategy allowing specific ablation of adult-born hippocampal neurons. This resulted in an impairment of spatial relational memory, which supports a capacity for flexible, inferential memory expression. In contrast, less complex forms of spatial knowledge were unaltered. These findings demonstrate that adult-born neurons are necessary for complex forms of hippocampus-mediated learning.

(Thank you, Deric Bownds at Mindblog.)

The best general reader book I've found on the topic of neuroplasticity and neurogenesis is the one by Sharon Begley, Train Your Mind, Change Your Brain: How a New Science Reveals Our Extraordinary Potential to Transform Ourselves .

The best general reader book I ever found on the topic of spatial brainmaps is Sandra Blakeslee's book,The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better. (This same author helped Ramachandran write his now-classic Phantoms in the Brain: Probing the Mysteries of the Human Mind.)

Both these authors' books have been discussed or the authors have been interviewed by Ginger Campbell at Brainscience Podcast; there are links to a discussion of Sharon Begley's book (episode 10), and Sandra Blakeslee's interview (episode 23, also #21), and others on neuroplasticity.

More reading:
1. The Reinvention of Self, a 2006 article by Jonah Lehrer in Seed about Elizabeth Gould's pioneering research into neurogenesis in marmosets