The influence of an inverted face on the McGurk effect

Abstract

The McGurk effect is a situation in which the perception of the speech signal is influenced by watching a talker’s face articulate a conflicting speech utterance. For example, observers typically report the syllable /da/ when the auditory syllable /ba/ is presented in synchrony with a videotape of the talker saying the syllable /ga/. It is well-known that inverted faces are much more difficult to recognize than faces presented in a normal, upright orientation. The current study investigated whether inverting the talker’s face would also influence the McGurk effect. Two groups of subjects were presented with a videotape consisting of conflicting auditory and visual syllables designed to produce the typical McGurk effect. The first group viewed the test tape on a video monitor set in its normal upright position. This group showed a typical, robust McGurk effect. The second group viewed the videotape on the monitor set in an inverted position. This group showed a significantly weaker McGurk effect. Thus inverting the face and the corresponding articulatory movements impacts on the integration of phonetic information from the auditory and visual modalities. [Work supported by NIH.]