Brain Plasticity

The hottest topic in neuroscience today is brain plasticity. This catchphrase refers to the fact that various types of experience can significantly modify key attributes of the brain. This field began decades ago by focusing on how different aspects of the developing brain could be impacted by early rearing conditions.  

More recently, the field of brain plasticity has shifted to studies demonstrating a remarkable degree of change in the connections and functional properties of mature and even aged brains. Thousands of published papers have now appeared on this topic, many by reputable scientists, and this has lead to a host of books, programs and even commercial enterprises touting the malleability of the brain with “proper” training. One is practically made to feel guilty for not taking advantage of this thriving store of information to improve one’s own brain or those of one’s children and grandchildren. 

My field of research is developmental neurobiology and I used to be a proponent of the potential benefits documented by brain plasticity studies. I am still of the opinion that brain plasticity is a real phenomenon, one that deserves further study and one that could be utilized to better human welfare. But my careful reading of this literature has tempered my initial enthusiasm.

For one thing, those selling a commercial product are making many of the major claims for the benefits of brain exercise regimes. It is also the case that my experiences outside the laboratory have caused me to question the limitless potential of brain plasticity advocated by some devotees.

Point in fact: Recently I had the chance to meet someone I had not seen since childhood. The person had changed physically beyond all recognition, as might be expected.  Yet after spending some time with this individual, his personality traits of long ago became apparent, including a rather peculiar laugh I remember from grade school.

Point of fact: a close colleague had a near fatal car accident, one that caused him to be in a coma for many days and in intensive care for weeks thereafter. Shortly after returning from his ordeal, this A-type personality changed into a seemingly mellow and serene person. But in less than two months, even before the physical scars of his accident had healed, he was back to his old driven self. 

For a working scientist to invoke anecdotal experience to question a scientific field of endeavor is akin to heresy. But it seems to me that it is foolish to simply ignore what one has learned from a lifetime of experiences. The older I get the more my personal interactions convince me that a person’s core remains remarkably stable in spite of huge experiential variations. With all the recent emphasis on brain plasticity, there has been virtually no attempt to explain the stability of the individual’s core attributes, values and beliefs. 

Here is a real puzzle to ponder: Every cell in your body, including all 100 billion neurons in your brain is in a constant process of breakdown and renewal. Your brain is different than the one you had a year or even a month ago, even without special brain exercises. So how is the constancy of one’s persona maintained?   The answer to that question offers a far greater challenge to our understanding of the brain than the currently in vogue field of brain plasticity.