Processing own-age vs. other-age faces: neuro-behavioral correlates and effects of emotion

Abstract

Age constitutes a salient feature of a face and signals group membership. There is evidence of greater attention to and better memory for own-age than other-age faces. However, little is known about the neural and behavioral mechanisms underlying processing differences for own-age vs. other-age faces. Even less is known about the impact of emotion expressed in faces on such own-age effects. Using fMRI, the present study examined brain activity while young and older adult participants identified expressions of neutral, happy, and angry young and older faces. Across facial expressions, medial prefrontal cortex, insula, and (for older participants) amygdala showed greater activity to own-age than other-age faces. These own-age effects in ventral medial prefrontal cortex and insula held for neutral and happy faces, but not for angry faces. This novel and intriguing finding suggests that processing of negative facial emotions under some conditions overrides age-of-face effects.

Figure 1. Facial Expression Identification Task

Trial event timing and sample faces used in the task.

Figure 2. Age of Face X Participant Age

(A) MNI: x = 21, y = 45, z = 9: Right medial prefrontal cortex, right anterior cingulate, right superior frontal gyrus (BA 9, 32, 10); (C) MNI: x = −36, y = 6, z = −3: Left insula, left claustrum, left putamen; and (E) MNI: x = −21, y = −9, z = −15: Left amygdala, left parahippocampus (BA 28); all showing own-age faces > other-age faces. The region of activation represents the F-map of the contrast; it is displayed on the standard reference brain in SPM. The crosshair indicates the peak voxel (local maximum) within the region of activation. Bar graphs show the mean (B) right medial prefrontal cortex and (D) left insula, both showing own-age faces > other-age faces for young and older participants for neutral and happy but not angry faces; and (F) left amygdala, showing own-age faces > other-age faces for older but not young participants. Parameter estimates (beta values) separately for Age of Face, Participant Age, and Facial Expression; betas for this region of activation identified by the F-contrast Age of Face X Participant Age extracted for each individual from a 6-mm sphere around the local maximum within the region of activation and averaged to produce a single value for each condition of interest respectively.