Neuroplasticity is Real!
Reference:1. Clark SA, Merzenck M. 1988. Receptive fields in the body surface map in adult cortex defined by temporally correlated inputs. Nature 332:444?5.
2. Sterr, A., Green, L., Elbert, T. 2003: ?Blind Braille readers mislocate tactile stimuli?. Biol Psychol. 63(2), pp. 117-27.
Close your eyes and see/visualize the outline of your body for 20 seconds.
Visualize each finger, your hands, elbows shoulder, trunk and your legs in as much detail as possible.
Go on, do it for 20 seconds before you continue reading. STOP READING NOW and do the visualization of your body. It will make this Report make more sense if you actually do this exercise.
I certainly hope you were compliant and did the simple visualization of the outline of your body. If not, then do it now!
Appreciate that you could do this task as you have a representation of your body parts in your somatosensory cortex. Basically your brain has a map of every part of your body which we know as the Homunculus.
Dr. Penfield, a pioneering neurosurgeon and a professor at McGill University, was the first person to map out the cortical homunculus in 1951 which is well known to us today. He suggested that the size of cortical representation also reflects kinesthetic proprioception, …the body as felt in motion.
It is now well documented that this Homunculus is not permanent. The brain changes based on the stimulus it is given.
For 3 decades now, scientists have done some fascinating (yet cruel) animal studies. For example they have shown that when adult monkey’s fingers are surgically sewn together for 5 months, the homunculus representations of the 2 fingers merge.
When the fingers are surgically split again and the monkey is once again able to use the fingers independently, their homunculus representations normalize again.
We know that tactile practice by reading Braille leads to an enlargement of the finger areas in the somatosensory cortex.
We also know that those who play the violin or piano have a relatively larger representation of their fingers in their motor cortex than non-players.
This is all positive if you are a violinist, golfer or a figure skater.
However this is negative if you are limping for a prolonged period of time after a knee injury or not moving and guarding yourself due to persistent low back pain.
Clinical Relevance: The brain changes based on how we use it or don’t use it, simple as that. The changes may take several months to occur.
The more often we are aware, sense and move in a specific pattern, the more the patterns get merged in the Homunculus.
The Homunculus has been shown to be disrupted in people with various pain disorders from CRPS to chronic LBP…but it can be “reversed” thanks to neuroplasticity!