In a novel study conducted to explore the relationship between the size of a brain structure and the ability to recover from traumatic experiences, it has been found out that the same region of the brain that is responsible for fear inhibition may also influence the overall personality of the individual.
It has already been found out from an earlier study that an area of the brain called the medial orbitofrontal cortex (mOFC) appears thicker in those who can control their emotional response to unpleasant memories in an effective way. The researchers carried out a follow up of the above study. At the end of the analysis, it was evident that study participants who exhibited better fear inhibition also score higher in measures of extraversion regarded as an energetic, outgoing personality.
The study is the first of it's kind to have established a definitive link between brain activity and structure, fear extinction and personality traits. Since earlier research has associated levels of extraversion and neuroticism - over sensitivity and emotional instability - with vulnerability to anxiety disorders, the current experiment focused on those traits.
Most individuals initially respond with physical and emotional distress to situations that bring back memories of traumatic events. However, such responses usually get attenuated over time as the situations are repeated without unpleasant occurrences. This phenomenon is commonly referred to as "extinction memory," the deficiency of which may manifest as an anxiety disorder.
The study participants were required to view a series of digital photos that featured lamps with either a red or a blue light shining. Varying degrees of electric shock was administered, ranging from mild to no shock. The participants were evaluated for the anxiety levels following this my measurement of perspiration on the palm of the hand. As a parallel approach, magnetic resonance imaging was carried out on the participant's brains.
Combining the results of the personality tests with the previously reported data revealed that a thicker mOFC and a superior ability to control the negative response associated with an unpleasant experience were found to result in higher levels of extraversion and lower neuroticism.
The results of the present study have several valuable clinical implications. One the measurement of brain structure can provide valuable clues regarding a complex character trait like extraversion. Second, it may provide for insights into personality disorders and other conditions like anxiety disorder that can help devise a new treatment plan for such conditions, which would in turn enhance the therapeutic benefit.