Cottrell, David, and Doyle, Eleanor (2013) Attention,
 ventriloquism
 and
 audio­-visual
 speech. In: Abstract Book of the International Symposium of Psycholinguistics. p. 40. From: 11th International Symposium of Psycholinguistics, 20 - 23 March 2013, Tenerife, Spain. (Unpublished)

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Abstract

[Extract] In 1996, Nature published a study by Jon Driver in which he demonstrated that accurate detection of audio-visual speech in a difficult attentional task was enhanced when the auditory source was displaced from the lip movements of the speaker. This finding appears to be at odds with the accepted conclusion that perception of audio-visual stimuli, including speech, is aided by temporal and spatial congruency. Since Driver’s original report there have been no published replications of the effect. In a series of experiments we attempted to replicate the effect and determine under what circumstances this counterintuitive effect occurred. We demonstrated that it is possible to replicate the effect but that it is exceptionally fragile. In the final experiment we hypothesized that the effect depends on the reliable production of a ventriloquist illusion. In this experiment we changed the displacement between the visual and auditory stimuli to maximise the ventriloquist illusion. We also obtained an independent measure of the illusion with the same displacement, with the same subjects. As in the earlier experiments, participants (N=32) were required to shadow word triplets spoken by a female speaker. The auditory stimuli were the target words and simultaneous distractor words spoken by the same female speaker. The auditory stimuli emanated from either directly under the video of the female speaker (congruent condition) or 16 degrees to the side (displaced condition). We again failed to replicate Driver’s effect with just the altered displacement condition. However, when the strength of the ventriloquist illusion was treated as a covariate in an ANCOVA, performance was enhanced in the displaced condition as predicted. We conclude that the enhancement of speech perception in noisy environments afforded by seeing the lip movements of the speaker depends on the perception of spatial congruency, either real or illusory.

Item ID:	26008
Item Type:	Conference Item (Poster)
Keywords:	audio-visual speech, ventriloquist illusion, displacement aided perception
Date Deposited:	14 May 2013 23:45
FoR Codes:	17 PSYCHOLOGY AND COGNITIVE SCIENCES > 1701 Psychology > 170112 Sensory Processes, Perception and Performance @ 100%
SEO Codes:	97 EXPANDING KNOWLEDGE > 970117 Expanding Knowledge in Psychology and Cognitive Sciences @ 100%
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