Irrelevant visual faces influence haptic identification of facial expressions of emotion

This study demonstrates that when people attempt to identify a facial expression of emotion (FEE) by haptically exploring a 3D facemask, they are affected by viewing a simultaneous, task-irrelevant visual FEE portrayed by another person. In comparison to a control condition, where visual noise was presented, the visual FEE facilitated haptic identification when congruent (visual and haptic FEEs same category). When the visual and haptic FEEs were incongruent, haptic identification was impaired, and error responses shifted toward the visually depicted emotion. In contrast, visual emotion labels that matched or mismatched the haptic FEE category produced no such effects. The findings indicate that vision and touch interact in FEE recognition at a level where featural invariants of the emotional category (cf. precise facial geometry or general concepts) are processed, even when the visual and haptic FEEs are not attributable to a common source. Processing mechanisms behind these effects are considered.