Research reportAge-related differences in brain activity during implicit and explicit processing of fearful facial expressions

- Implicit and explicit cerebral networks change with increasing age.
- More frontal areas are activated in older adults during explicit recognition of fear.
- This additional activation is not sufficient to compensate for difficulties.
- We did not observe cerebral differences between age groups in the implicit task.
- In both tasks, there were no differences in amygdala activity between age groups.

Age-related differences in neural correlates underlying implicit and explicit emotion processing are unclear. Within the framework of the Frontoamygdalar Age-related Differences in Emotion model (St Jacques et al., 2009), our objectives were to examine the behavioral and neural modifications that occur with age for both processes. During explicit and implicit processing of fearful faces, we expected to observe less amygdala activity in older adults (OA) than in younger adults (YA), associated with poorer recognition performance in the explicit task, and more frontal activity during implicit processing, suggesting compensation. At a behavioral level, explicit recognition of fearful faces was impaired in OA compared with YA. We did not observe any cerebral differences between OA and YA during the implicit task, whereas in the explicit task, OA recruited more frontal, parietal, temporal, occipital, and cingulate areas. Our findings suggest that automatic processing of emotion may be preserved during aging, whereas deliberate processing is impaired. Additional neural recruitment in OA did not appear to compensate for their behavioral deficits.