The Talking Face: Effects of Concurrent Speech on Hemispheric Lateralization of Face Recognition

Abstract

In recognition of the ecological importance of processing the talking face and its potential role in the development of right hemisphere specialization for face processing, descriptive studies examined the effects of concurrent speech on hemispheric lateralization for face recognition. To explore the potentially special nature of the face-speech concurrence, the effect of speech on inverted face recognition was also examined. Separate groups of right-handed participants took part in each of 4 studies.

In Study 1, participants were asked to identify which of 4 male faces was presented in tachistoscopic fashion via computer. Correct recognition of faces was significantly faster in the left visual field (LVF) than in the right visual field (RVF), and the majority of participants exhibited a LVF processing-speed advantage (ADV). However, those participants whose responses to faces were faster in the RVF (RVF ADV) were more accurate at recognizing faces.

In Study 2, a spoken word was incidentally presented simultaneously with each face. This altered hemispheric lateralization for face recognition. There was no longer evidence for LVF responses being faster than RVF ones or for participants with a RVF ADV being better at recognizing faces. However, these participants were superior at an unannounced speech recognition test.

Unexpectedly, concurrent processing did not diminish performance on face recognition. Good memory for the incidental speech was also evident during an unannounced speech recognition test, indicating that participants successfully did 2 things at once. It was hypothesized that the special nature of the face-speech combination was responsible for this. Concurrent processing of the nonecological combination of inverted faces and speech provided no evidence in support of this hypothesis.