The effect of inserting an inter-stimulus interval in face-voice matching tasks.

Voices and static faces can be matched for identity above chance level. No previous face-voice matching experiments have included an inter-stimulus interval (ISI) exceeding 1 s. We tested whether accurate identity decisions rely on high-quality perceptual representations temporarily stored in sensory memory, and therefore whether the ability to make accurate matching decisions diminishes as the ISI increases. In each trial, participants had to decide whether an unfamiliar face and voice belonged to the same person. The face and voice stimuli were presented simultaneously in Experiment 1, and there was a 5-s ISI in Experiment 2, and a 10-s interval in Experiment 3. The results, analysed using multilevel modelling, revealed that static face-voice matching was significantly above chance level only when the stimuli were presented simultaneously (Experiment 1). The overall bias to respond same identity weakened as the interval increased, suggesting that this bias is explained by temporal contiguity. Taken together, the findings highlight that face-voice matching performance is reliant on comparing fast-decaying, high-quality perceptual representations. The results are discussed in terms of social functioning.