Who do you think you are?

Do our brains define who we are?

The study of the self, what makes us unique and how our brains define who we are is an intriguing and often controversial area of research. Indeed, such work may eventually shape many aspects of society from education to criminal justice.

We already know that damage to the brain can permanently alter an individual’s personality and that the type of alteration depends on the region damaged. One of the most famous examples of brain damage leading to a shift in personality was the case of Phineas Gage. Gage worked as a foreman leading a team of workers preparing the ground for a new railway line. On the 13th September 1848 an accidental explosion blew an iron rod, over 3 feet long and 1 ¼ inches in diameter at its widest point, clean through his head. Although amazingly he survived the incident, he lost sight in his left eye and suffered significant damage to his left frontal lobe. Following the accident, although his intellect remained intact, it is reported that he changed from being a conscientious well liked man to a fitful disrespectful individual with a particularly foul mouth. Indeed, the changes in his personality were so significant that his former employers were forced to let him go.

Gage’s tragic accident was one of the first pieces of evidence linking frontal cortex damage to antisocial personality traits. The knowledge that such physical brain-damage can precipitate a change in personality raises the question of whether undesirable traits seen within the general population can be linked to subtle changes in brain function and ultimately whether these ‘defects’ may be treatable.

An area where a combination of genetics and functional brain imaging is raising just such a question is the study of psychopathology. Scientists have observed genetic and physiological differences in the brains of a number of diagnosed psychopaths. Specifically, brain scans of these individuals reveal lower than average activity and reduced communication between the orbitofrontal cortex and amygdaloid brain regions. Together these regions are important for making emotionally driven decisions, learning from the emotional content of experiences and controlling impulsive behaviour.

These brain changes are often seen in combination with a rare form of the monoamine oxidase A (MAO-A) gene known as the ‘warrior gene’. This gene codes for a protein (MAO-A) which can influence the communication of cells in a number of brain regions. Alterations in this gene lead to abnormal cellular communication, and have also been linked to behavioral abnormalities.  Indeed, individuals with the ‘warrior’ version of this gene are more susceptible to developing antisocial and often violent tendencies, especially if they also experienced maltreatment during early childhood.

Professor Fallon uncovered a long list of murderers and suspected murderers on his dad’s side of the family

Although studies of many psychopathic killers reveal the presence of both the ‘warrior gene’ and reduced orbitofrontal/amygdaloid activity, this is by no means the end of the story. Amazingly James Fallon, a neuroscientist from the university of California who had been studying the brains of psychopaths, recently uncovered some disturbing family history of his own; leading to the disquieting revelation that he himself showed both the same brain type and genetic profile as the psychopathic killers he studied. Although he admits to not always being in-tune with other’s emotions, professor Fallon is a caring husband and father who has never been in trouble with the law. These findings raise the question of how important a biological predisposition towards psychopathy is and how this may be overcome. Professor Fallon notes that he was lucky to have a very warm and loving childhood, and believes that his upbringing likely played a role in preventing any biological tendencies toward psychopathy from taking effect.

Work such as this is beginning to uncover the amazing interplay between our brains and our selves. However, as knowledge in this area increases, many of us can’t help but question where this research is leading and how these findings may be used. Although I believe we are a long way from hearing ‘my brain made me do it’ as an acceptable defence in our courts, this research is already influencing our education system. One pioneering school in the south of England accepts children with behavioural difficulties associated with low amygdaloid function. Along with their regular lessons children are taught how to recognise and respond to emotions in a socially acceptable manner. These children are considered to be at risk of developing antisocial or even psychopathic tendencies and it is hoped that this training will help them integrate into society and lead normal successful lives.

Post by: Sarah Fox