Abstract
The brain regions involved in emotion processing (e.g., the amygdala, prefrontal cortex) develop dramatically between childhood and adulthood, especially during adolescence. These changes are reflected behaviourally, with the ability to label or match facial expressions improving over time. Facial expressions can be subject to explicit conscious appraisal and evaluation, but they can also be processed implicitly. Implicit and explicit facial expression processing may be differentially affected by development. The aim of this study was to examine implicit and explicit processing of facial expressions in children (aged 6–7 years), adolescents (aged 11–15 years) and adults (aged 20–44 years). In addition to behavioural data, event-related potentials and facial electromyography were collected to index emotional processing. Happy, angry, fearful and neutral faces were presented and participants were asked to judge the sex of the face (implicit task) or the expression (explicit task). Differences in expression processing were evident at the face-sensitive N170 component measured over occipito-temporal regions. For adults, the N170 response was enhanced to negative (angry, fearful) compared to positive (happy) expressions, for both implicit and explicit tasks. The N170 amplitude for adolescents was reduced compared to that observed for the adults. In addition, implicit and explicit facial expression processing differentially affected the N170 component in the adolescents. Although, N170 amplitudes for the children were large, they did not differentiate between the expressions. The results suggest that there is a critical transition period between childhood and adolescence, which affects both implicit and explicit facial expression coding.
This research was supported by Macquarie University and the Australian Research Council.