Lateralization for the expression and perception of facial emotion as a function of age.

In order to test the hypothesis of right hemisphere changes with age, this study examined lateralization for facial emotion in young, middle-aged, and older women (N = 90). For expression, subjects were photographed while posing positive and negative emotions. Composite photographs were created and rated for intensity. For perception, subjects were required to make intensity judgements about emotional chimeric faces. Overall, subjects demonstrated significant left-sided facial asymmetry for expression and significant left hemispace biases for perception. The findings for facial expression were not influenced by emotional valence or resting face asymmetries. There were no changes in lateralization as a function of age for either expression or perception. Taken together, these findings lend support to the notion that the right hemisphere mediates emotional processing across the adult life span.