Bodymaps and “sensorimotor amnesia”

Ok let’s follow this theme and see where it leads us.

One thing I didn’t really emphasize in that first post is this idea of “sensorimotor amnesia” described by Thomas Hanna. My first google search for sensorimotor amnesia led me to this great post on Todd Hargrove’s “Better Movement” blog (which is consistently fantastic, check it out if you’re interested in moving better).

The idea is very simple and hopefully familiar to all of us: parts of our bodies which we don’t use much become “forgotten”, we lose our ability to move them in a coordinated way and often we can’t even really feel them at all. A lot of us can’t really tell what our shoulder blades are doing, where they are in space or how they are moving. Other commonly forgotten areas include the “rotator cuff” muscles and others connecting the shoulder blades to the humerus (upper arm bone), the deep hip muscles, pelvic floor and deep abdominal muscles, the intrinsic muscles of the feet, back extensors and deep spinal muscles, muscles between the ribs…it can happen anywhere in the body, depending on each individual’s history of movement.

Everyone who has done any fun movement or fitness classes of any sort will remember a time when some movement had them feeling and engaging parts of their body that they “didn’t even know existed”.

So, you can’t feel your right hip very well compared to other parts of your body, and you can’t move it voluntarily in a coordinated way, this means that the parts of the “maps” in your brain representing your right hip are not “wired up” as well as other parts. There may be less neurons devoted to creating an internal “picture” of the right hip. Whatever neurons are being used for that may not be as well-connected synaptically to each other, to neighbouring areas devoted to the pelvis or thigh, or to other areas responsible for vision or balance or self-image. They may even be over-connected to brain areas concerned with fear or perceived threat or memories of pain. The pathways between these connected neurons can also be less “myelinated” (myelin is “white matter” which makes an insulating sheath that grows around neurons allowing for faster transmission along the nerve), making the “signal” slower and weaker.

All of these parts of the brain are constantly re-modelling themselves according to changing stimuli.

So most of what we call “Yoga” or “Qigong” or whatever is an exploration our own sense of our bodies, as they are represented in the different “bodymaps” in our brains. Each of these maps is often referred to as a “homonculus”, (which I believe means “little person”, in Greek) so a term being used in neuroscience-oriented physiotherapy circles (these circles are still fairly small, but growing!) to describe a wide range of activities is “homoncular refreshment”.

Let’s do a bit of quick and easy neuro-anthropological translation: The above video was the first result of a google search for “Chinese pai da”, an extremely common form of exercise which you can see hundreds of people doing every day in any park in China. Pai da “patting and hitting” sets are found in almost every system of Chinese martial art and “Qigong”. The traditional explanation is that such exercises “improve the flow of Qi and blood through the meridians”. We can now translate this and say that such exercises “refresh and improve the resolution of bodymaps in our brains including but not limited to the somatosensory cortex”. Regular practice of such exercises will, according to established principles of neuroplasticity, reduce and reverse the process of sensorimotor amnesia, helping us to develop and maintain a more complete cortical map of the vascular and neural activity through the surface of the body.

Interesting. Waking the body up with tactile stimulation of nerve endings = “stimulating the flow of Qi”.

So what else?

Above is a classic picture depicting the “Chakras” and “nadis” described by ancient Yogis like Goraknath and Milarepa. Below is a picture of the main branches of the human nervous system (if it showed all of the little branches all we’d see is a human-shaped ball of fuzz):


Now, I ask you, which is more likely: a) that ancient yogis were feeling some sort of magical non-physical energy while they were focusing on their bodies in meditation, b) that “yoga” is bullshit, “prana” is not real, and “chakras” don’t exist, or c) that pictures like the one above are depicting the subjective experience of how the body feels to a highly trained nervous system?

Given that it’s the job of the nervous system to feel and control the body, I am leaning towards option c).

Vipassana anyone?

More to come. I’m going to keep going on this theme, but figure I’d might as well just chuck stuff up here whenever I get some time to write, rather than trying to make each post perfect and complete at this early stage.

PLEASE tell me if any of what I’m writing is wrong or unclear, and especially if you think I’m mistaken about any of the neuroscience. I’m new to this blogging business and still just pulling random pictures of the internets as well so if I’ve used your picture and you’d prefer it if I didn’t, just let me know. Thanks.

Body Maps – changing bodies in our heads.

It’s funny how when there is a lot to say, it’s often easier to say nothing. Save the energy, because you know it’ll be a long conversation once you start. This happens to me all the time when people ask “so what do you do?”…I nearly always cringe internally, look off into the distance and think to myself “what am I going to say this time?”…Oh well I’ll just start writing anyway, even though I know I’ll have to go back through what I write again soon, adding references (and revising what I no longer agree with).

So there’s a lot to say on this whole topic of “ancestral movement”. But we have to start somewhere, so today I’m going to begin by writing about “body maps”: the various parts of our brains in which our bodies are represented topographically (like a map) and through which we can know things like where we are in three-dimensional space; where our head, torso and limbs are in relation to each other; what’s happening on the surface of our body or in the space around it; where and how fast we are moving and/or where we could potentially be moving; and how we feel about all this.

If we understand body maps and neuroplasticity we can gain a lot of insight into the methods and benefits of a wide range of physical or body-mind practices from any number of different cultures.

Some basics:

Physical and cognitive abilities are “plastic” – they develop in response to the demands placed upon them. Thus:

– It is possible (actually easy) to feel more of the body, in greater detail, with practice.

– It is possible to control movement with ever greater precision.

– It is possible to feel activities taking place inside the body, with more precision and in greater detail.

– Sensitivity to our own bodies is closely related to our ability to “feel” or “read” the bodies and movements of other creatures.

– It is also possible to become more aware of the space around the body and the potential for movement within it, and thus of the space and potential for movement around others’ bodies.

– Finally, it is possible to change how we feel about any and all of these things: the different parts of our bodies, movements, the feelings from the insides of our bodies, the space around us, and what we sense from others.


How does it work?

The classic first example of topographical representation of the body in the brain is in the somatosensory cortex. Tactile stimulation of the foot (whether real or imagined) is associated with activity in neurons in the “foot” area of the brain as shown in the picture. Stimulation of the knee, thigh, hip, trunk, etc each cause activity in the corresponding areas of the cortex, and these areas in the brain are adjacent to each other just as they are in the body:

Just in front of the somatosensory cortex is the primary motor cortex, one of the main parts of the brain active in control of physical movements, decisions to move, thoughts about movement, etc.

Now: these maps aren’t fixed! They are constantly being updated according to where we are directing our attention and what we are aware of, and according to what we are actually asking our bodies to do, moment to moment, hour after hour, day after day, year after year. If you put your hand in a caste so the fingers are fixed together, the parts of the somatosensory and motor cortices covering the separate fingers and complex motor patterns of the hand will gradually atrophy and fuse together. Most of us don’t do that very often, but think about what is normal in our culture to do with our feet: from an early age we confine the feet into little mittens with our socks and shoes, so that the extremely sensitive and dextrous exploratory feet we have in infancy quickly become rather deadened “solid bits at the ends of our legs”.

The increased sensitivity, mobility, balance and agility we can get by walking and running barefoot or doing ballet exercises for our feet comes primarily from re-organization of the brain and nervous system. [See Merzenich’s work in “The Brain That Changes Itself”, or Kandel’s “Principles of Neural Science”, I’ll come back with some page numbers once I unpack my books.]

So, if we in our quests for self-knowledge or our paths to good health or journeys to kung-fu mastery wish to improve our ability to feel and move all of the different parts of our bodies, how should we go about it?

Firstly, once we recognize that we are now talking about neuroplasticity or “changing the brain” we can apply some simple rules that will make our practice more effective:

– Intensity of focus, emotional engagement, and repetition (number of instants spent performing the activity) are the main factors behind all learning.

– Sensitivity to subtle stimuli and small movements increases whenever we reduce stronger stimuli and large movements (according to the Weber-Fechner law).

– Processing, mental rehearsal and integration of learning happen during rest periods – the rest periods are just as important as the movements themselves.

So if I want to gain full awareness of the positions, movements and potential movements of each of the 25 or so bones of my spine, I will need to focus my attention as intensely as possible on each vertebral segment individually and explore as many ways of moving it as I can in flexion-extension, lateral flexion and rotation, anterior-posterior translation, side-to-side translation, and superior-inferior translation.

So while exploring my own spine I came up with these kinds of movements:

I can improve my learning if I can focus my attention very intensely on the part of the body I am trying to become more aware of, if I can make myself more emotionally engaged or inspired about why improving my spinal awareness is important to me or how amazing it is to feel the living moving body or something, and also if I repeat the exercise frequently. Visualizing the results of the practice and the method to achieve them (imagining the improvement after one month’s practice, one year’s practice, ten year’s practice, etc) will also help to organize and contextualize our learning and improve or maintain emotional engagement and intensity of focus, encouraging me to repeat the exercises more often. I can also allow rest periods immediately after performing the movement explorations, and further improve awareness of the areas that have been worked by paying close attention to residual sensations of warmth, blood flow, tingling etc. The exact form of the movements is less important than the exploratory approach.

Now those videos show how focusing attention and movement on one part of the body (like a vertebral segment) also improves our awareness of the movements and positions of other parts of the body which are associated with the part we are focused on. Focus attention on the belly button as it moves around and you improve awareness of the related movements of the lumbar spine, the other parts of the spine, the hips and shoulders, and so on. If we wanted to improve our awareness of and control over other areas we could just as easily perform mindful circles or figure 8’s or other shapes with movements of the toes, heels, knees, individual hips, or even the eyes and tongue.

Some novel movements for training the shoulder:

Like this we can improve the detail and resolution of our own body awareness, and feel when and how much each little part of our body is contributing or not to whatever activity we are engaged in, integrating the increased awareness of whichever parts we have been exploring into normal everyday activities like walking, running, sitting down, standing up, squatting, picking things up, lying down, rolling over, etc. Or into our sport or martial art. Or into our meditation posture.

Our practice will also make us more sensitive to the ways that other people and other creatures hold and move these parts of their bodies. Practice segmental spinal movements and you’ll start seeing them everywhere. (Which is nice.)


More on this stuff soon, taking it further into the “association areas” where the senses are integrated and associated (!) with other things (like memories); into the “limbic system” where experiences get their emotional “affect”, and also once more into the importance of slowing down.