Abstract
When a background auditory rhythm is played, visual objects are processed faster when presented in synchrony with the beat than out of synchrony, reflecting the oscillating entrainment of attention (Brochard et al., 2013; Escoffier et al., 2010). The present study aimed to investigate whether attentional entrainment induced by an irrelevant rhythm modulates the holistic perception of faces by using the composite face illusion. Participants had to judge whether the top half of a face belonged to “Nicolas Sarkozy”. Three conditions were used: “same” (the bottom half of the face also belongs to “Nicolas Sarkozy”),”bottom different” (the bottom half belongs to an unknown person), “different” (both halves belong to an unknown person). The two parts of the face were aligned or misaligned. A rhythm was played during the task and the onset of faces was in-synchrony (on-beat) or out-of-synchrony (off-beat). Results showed the composite face effect in accuracy: i.e., deteriorated performance for recognizing “Nicolas Sarkozy” in the upper part of the face when it is aligned with the lower part of another face as compared to misaligned. No main effects or interactions involving synchrony were found in accuracy. Interestingly, in correct RTs, the composite face effect (i.e., slower processing for aligned “bottom different” faces than misaligned ones) interacted with synchrony, as it was observed only when faces were presented on-beat. Indeed, shorter responses were found for misaligned “bottom different” faces presented on-beat as compared to off-beat, whereas synchrony did not speed up responses for aligned “bottom different” composite faces (i.e., the ones eliciting the illusion). Because correct RTs in this condition reflect the time needed to accurately recognize the upper part of the face without taking into account the misleading lower part, the present results suggest that auditory entrainment of attention might enhance the holistic perception of faces.
Meeting abstract presented at VSS 2015