Monday, September 24, 2007

Body Maps

Since my new book, The Body Has a Mind of its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better arrived I've been buried in it. The Blakeslees have written a very good book, (even if they didn't include a reference list).

Ginger Campbell MD has an excellent podcast about this book. Visit her show notes here.

This book, and for those in a hurry, the podcast, affords us a long leisurely look into the brain and its workings (especially after having just read Rhythms of the Brain!) The brain creates several maps, mostly in the parietal lobes, mostly of the body itself (the human antigravity suit itself, inside and out) but also of the space around the body - it will change the maps to include any tool that is being used, for example, a cane used by a blind person to navigate along a street. The kinesthetic/motor map stretches out to include the cane, spreads over the visual cortex, and enables the person to "see" the sidewalk through their body.

The brain turns on as soon as it forms embryologically, starts to function even as it still grows (the frontal lobes are not fully grown for a couple decades), and does not ever turn off until the moment we die. Even while we are sound asleep, it is still working away, keeping our lungs breathing and our heart beating. Amazing. First there is movement, then through feedback from the movement and subsequent encounter with the environment, the brain refines its maps of space and how the body fits into them. Strokes and other neurological twists of fate can lead to some very strange mapping problems, like the feeling of having three arms, or only one, or that a limb does not belong to one and must be amputated.

Of interest to me as a manual therapist is a careful and lengthy explanation of various dystonias and what is thought to happen to the mapping in association. Stress-free practicing of any honed motor skill is advised; just practicing mentally (e.g., golfing) will preserve mapping with good fidelity - the brain will use premotor maps, so no need to burn out your actual motor maps. Musicians will find this an important book to read, sports enthusiasts, anyone who uses their body for skilled performance of any sort.

When I think about how I use my own body, I realize I'm not apt to incur dystonia over time. For one thing, I don't rush, and for another, I never do the same thing twice, the same way, ever.

Tuesday, September 04, 2007

"Rhythms of the Brain" by György Buzsáki

I've been engrossed in this book ever since it arrived into my hot hands last week. The first sentence reads:
The short punch line of this book is that brains are foretelling devices and their predictive powers emerge from the various rhythms they perpetually generate. At the same time, brain activity can be tuned to become an ideal observer of the environment, due to an organized system of rhythms.

He writes in the introduction;

My connection with brain rhythms began in April 1970, during a physiology lecture given by Endre Grastyán in the beautiful town of Pécs, on the sunny slopes of the Mecsek mountains in Hungary. The University of Pécs, or Universitas Quinque Ecclesiensis, as it was called when founded in 1367, has produced a remarkable set of neuroscientists, including János Szentágothai, the legendary neuroanatomist; Béla Flerkó and Béla Halász, pioneers of neuroendocrinology; György Székely, the renowned spinal cord physiologist; and Ferenc Gallyas, the creator of the silver impregnation methods widely used for neuronal labelling.

He goes on to talk about Grastyán's path to neuroscience, then comes back to the intersection of his own life with that of his mentor and inspiration, i.e. Grastyán himself:

In that particular lecture of April 1970, he talked about how the brain outputs, such as movement and cognition, control its inputs, rather than the other way around. His key idea was that control in living systems begins with the output. This is the seed for further evolution of the brain. Even in the most complex animals, the goal of cognition is the guidance of action. Indeed, the first simple biological systems did not have any inputs; they did not need them. They simply used an economical motor output, a rhythmic contraction of muscles. This is, of course, sufficient only when food is abundant in the sea environment. More complex forms of life evolved from this simple solution by modifying the simple rhythmic output. Sensation of direction and distance developed only after the "invention" of movement through space. The idea of output control and feedback is a profound thought even today. Back then, when Pavlovian sensory-sensory association was the dominant ideology in the East and the stimulus-decision-response paradigm dominated Western thinking, Grastyán's teachings were unusual, to say the least... in his physiology lecture, Grastyán was talking about some truly intriguing questions that sparked my interest. I applied to become his apprentice and spent most of my student life in his lab.

A note - Buzsáki was in med school at the time.

His book is a treasure, deliberately written for general readership but minus any dumbing down or tedious linearity/tunnel vision. He reminisces about lunchtime conversations fondly;

The best training in Grastyán's laboratory occurred through my participation in the regular lunch discussions that could go on for several hours, where topics meandered chaotically from homeostatic regulations of the brain to complex philosophical topics. It was during those lunch lessons where I first leaned about the hippocampal "theta" rhythm, the oscillation that has become my obsession ever since... As I have repeatedly discovered in my career, the informal lunch-seminar approach to science is hard to substitute with formal lectures or the reading of dense scientific papers. Seminars are tailored for an average group of people with the naive assumption that the audience retains all the details and follows and accepts the fundamental logic of the lecturer. In contrast, the essence of lunch conversation is to question the fundamental logic, a quest for clarification and simplification, a search for explanations and answers without a rigid agenda, where the focus is not on covering large chunks of material but on fully understanding even the smallest details. Of course, one can follow up a lecture by finding and reading the relevant published papers on the topic. However, most of the exciting findings in neuroscience are hidden in the small print of specialty journals, often written in a specialized and arcane language comprehensible to, at most, a handful of specialists. Overwhelmed with new and important discoveries in the various sub-subspecialties, the practicing neuroscientist, such as myself, tends to forget that neuroscience is of startling relevance to a contemporary society wrestling with complex issues such as social behavior, depression, and brain aging. It is hard to predict which of the numerous fundamental discoveries could alter the face of such large issues, and unless they are conveyed to others, they might be overlooked without making an impact. This is mainly so because the explanations we provide in papers to the superspecialists may be impenetrable to the uninitiated. Without attempting to place our work into a larger context from time to time, we deprive ourselves of the chance to be able to connect to the more macroscopic and microscopic levels of research. Yet, discoveries and insights realize their power only when understood by others. Understanding this important connection is what mostly motivated me to write this volume.

The entire book is written in this conversational style, but be aware that footnotes are to be found on nearly every page, dense with bibliographical/ historical/ explanatory detail. He explains the impact on neuroscience of several fields of science, including but not confined to complexity theory, consideration of temporal domain, why fundamental mathematical understandings are important. He takes care of both "why", and "how". His book does not contain chapters, instead he has broken his book into "Cycles", that unfold outward sequentially but also radially from a core, like a good orchestral symphony. If anyone has ever succeeded in giving a readership a sense of kaleidoscopic expansion of concept, a feeling of putting new ideas into order, it is this writer. A sense of movement is part of the reading of this book - he carries the reader along swiftly, effortlessly, gently and surely, providing long, sustained, spherical vistas into the knowledge base from lofty heights, as surely as any experienced and people-skilled mountaineering guide would do for a novice hiking group (minus sweat and exhaustion!), providing opportunities to examine the view from various pinnacles, ensuring not only that the experience provides memories to last a lifetime, but taking great personal pains to provide the possibility that the reading experience itself will be life-changing/enhancing/motivating. No one will come away from this book still ignorant of neuroscience, with no clue of how the brain works, of how the organism is integrated into it, of how it is integrated into the organism, or not able to "feel" the material on some level of being.

No one would regret reading this book. Highly recommended.

I will be bringing more of his book here over the next little while.