Abstract
Aftereffects have been demonstrated for various types of visual stimuli including faces and emotional facial expressions. Aftereffects are assumed to be mediated by neural adaptations, but brain responses during the perception of facial expressions aftereffects have not been measured. In the current study we measure event related potential (ERP) brain responses in an emotion aftereffect paradigm with happy and sad faces. Participants were 22 undergraduate students (13 females) (Mean age = 19.6 years; SD = 1.98). First, we replicated previous behavioural results of emotion aftereffects: after fixating a happy face, a neutral face was more likely to be labelled sad, and vice versa. We also found that ERP amplitude was predicted by the strength of the aftereffect, when the percept was happy. Interestingly this was not found with neutral faces perceived as sad, which may indicate different processing mechanisms for positive and negative facial expressions. The fact that the brain response in viewers who perceive the neutral face as happy resembles that of the brain response to a happy image, rather than a neutral image, suggests a brain basis for facial aftereffects.
Meeting abstract presented at VSS 2012