In a recent post I emphasised how alike our brains are in the performance of many functions including processing, encoding, storing and recalling information. While this remains very much the case it’s also important to acknowledge the unique aspects of individual brains. As I put it before we are all walking the same internal path, but the details are different. The complex interaction between genes and environment mean that our brains, just like our bodies, come in different sizes, shapes and colours with individual features and peculiarities.
Through post-mortem dissections, brain-imaging studies and electrophysiological recordings of brain activity researchers have exposed many biological differences in individual brains, including variability in the
- average speed at which synapses-the point on our brain cells at which information is exchanged- pass information to one another
- pathways in which neural information flows from one area to another
- size of the surface area of functionally independent neural regions
- size and sensitivity of various neural structures
- presence of various neurotransmitters and hormones
It should go without saying that differences in brain composition and function give rise to the varying dimensions of personality observed within a population. In fact, the developing field of personality neuroscience has been using the advanced methods and technologies of the neurosciences to correlate identified personality “types” with variations in brain organization, neuronal connectivity and cerebral structures.
As well as contributing to biological theories of personality however, the ability to measure and observe material differences in individual brains has important pragmatic implications. Within the clinical setting for instance, disparities in the brains of different individuals equates to variations in individual responses to a whole range of very common health issues including ageing, recovery from stroke, depression and other mental conditions. Physicians for this reason, have had to become adept at tailoring the treatment and treatment schedules prescribed for most medical conditions to the specific needs of the patient.
Identifying differences in individual brains may also soon be an invaluable aid in the diagnostic process. For instance, recent studies have found a reliable association between the presence of an Alzheimer’s risk gene and differences in the volume of certain brain areas in young adults, long before the typical age onset of Alzheimer’s disease. With further research into such associations and the development of more advanced, user-friendly brain-imaging and recording devices it might some day be possible to diagnose a persons susceptibility to various medical conditions through an assessment of the individual morphology of their brain.
Other research into brain differences has revealed structural differences between male and female brains as well as how neuronal differences might influence peoples conscious experience of the world. Both areas I hope to explore in future posts.
For now however, I’ll leave you with a final thought. Much like your unique body, your brain is distinctly yours. As well as being endowed with specific neuronal characteristics from your inherited genetic program, certain details of your brain have changed themselves to suit you, to respond to your experiences, to adapt to your environment. Another thrilling feature of the neuronal galaxy that brings about our being.