Authors:

LAWRENCE, A.D. & MURPHY, F.C.

Reference:

Year of publication:

2001

CBU number:

5191

Abstract:

The role of hemispheric asymmetry in emotion has long been a topic of controversy. While early theories highlighted the importance of right hemisphere function in emotional processes, more recent human lesion and electrophysiological studies point towards differential involvement of left and right frontal cortical regions in the experience of positive and negative emotion, respectively. The recent application of functional neuroimaging to the study of emotion offers new data that may be useful in testing this latter hypothesis, but conclusions drawn from individual studies are often compromised by limited statistical power and suboptimal control conditions. In the present study, we combined data from over 20 studies of positive (happiness, pleasantness) and negative (sadness, anger, fear, guilt, disgust, anxiety, unpleasantness) emotions induced using varied mood induction techniques (retrieval of emotional memories, film clips, affective pictures); all included a neutral emotion condition and mood manipulation check. Peak frontal maxima points from these studies were superimposed onto the standard Statistical Parametric Mapping brain surface. The pooled results for positive emotions showed consistent activation of medial and dorso-medial frontal cortical regions, particularly in the left hemisphere; for negative emotions, bilateral activation of ventral, ventro-lateral, and medial prefrontal cortex was observed. These findings are not entirely consistent with previous work on hemispheric differences in emotion. Methodological and theoretical explanations for these differences are considered.