Molecules to Mind: the Construction of Emotion

Abstract

In recent years, there has been increasing scientific interest in the biological basis of emotion. By characterizing the neural and genetic basis of affective functioning, new research has the potential to contribute to our scientific understanding of both typical social development and aberrant trajectories for emotional disorders. The four studies detailed here investigated the biological substrates of affective functioning from a multiple-levels-of-analysis perspective in order to understand potential interactions of genes, the brain, personality and behavior in emotion. The first study examined the relationship between personality and the ways in which individuals look at faces. Results indicated a robust positive correlation between the personality trait of neuroticism and the amount of time spent looking at the eyes of faces, especially the eyes of fearful faces. A follow up study found that subjects high in neuroticism also fixated most on fearful faces placed within an array of objects. This effect remained strong even when controlling for negative mood state. The second study involved an experimental manipulation of activity in the face processing system of individuals with autism. The results showed that by manipulating visual scanpaths to involve increased fixation on the eye region of a face, the hypoactivation of the amygdale and fusiform gyri, an established characteristic of social brain functioning in autism, was temporarily reversed. A third study investigated the neural correlates of emotion regulation across development using functional magnetic resonance imaging (fMRI). Results revealed increases in anterior cingulate to amygdale connectivity during episodes of regulatory demand. Magnitude of ACC activity was correlated with both age and levels of fearful temperament in children. Finally, the last study integrated the results of previous experiments and illustrated interactions among a common polymorphism in the serotonin transporter gene (5HTTLPR), brain activity, personality, and visual scanpaths. Results contribute to the growing body of literature characterizing the development of individual differences in the perception, feeling, and regulation of emotion. In addition, these findings have the potential to inform our understanding of abnormal emotional development by detailing a complex system in which genetic vulnerability produces increased attention to emotionally arousing aspects of the environment through differential brain activation.