City Research Online

Abstract

Sight and sound are out of synch in different people by different amounts for different tasks. But surprisingly, different concurrent measures of perceptual asynchrony correlate negatively (Freeman, Ipser et al, 2013. Cortex 49, 2875–2887): thus if vision subjectively leads audition in one individual, the same individual might show a visual lag in other measures of audiovisual integration (e.g. McGurk illusion, Stream-Bounce illusion).

This curious negative correlation was first observed between explicit temporal order judgements and implicit phoneme identification tasks, performed concurrently as a dual task, using incongruent McGurk stimuli. Here we used a new set of different of explicit and implicit tasks and congruent stimuli, to test whether this negative correlation persists across testing sessions, and whether it might be an artefact of using specific incongruent stimuli. None of these manipulations eliminated the negative correlation between explicit and implicit measures. This supports the generalisability and validity of the phenomenon, and offers new theoretical insights into its explanation.

Our previously proposed ‘temporal renormalization’ theory assumes that the timings of sensory events registered within the brain’s different multimodal sub-networks are each perceived relative to a representation of the typical average timing of such events across the wider network. Our new data suggest that this representation is stable and generic, rather than dependent on specific stimuli or task contexts, and that it may be acquired through experience with a variety of simultaneous stimuli. Our results also add further evidence that speech comprehension may be improved in some individuals by artificially delaying voices relative to lip-movements.

Publication Type:	Article
Additional Information:	© American Psychological Association 2018. This paper is not the copy of record and may not exactly replicate the authoritative document published in the APA journal. Please do not copy or cite without author's permission. The final article is available, her http://psycnet.apa.org/doi/10.1037/xhp0000535.
Publisher Keywords:	Individual differences; multisensory integration; perceptual timing; speech perception
Departments:	School of Health & Psychological Sciences > Psychology

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