A Psychophysical Investigation of Differences between Synchrony and Temporal Order Judgments

School of Psychology, University of Glasgow, Glasgow, United Kingdom
PLoS ONE (Impact Factor: 3.23). 01/2013; 8(1):e54798. DOI: 10.1371/journal.pone.0054798
Source: PubMed


Synchrony judgments involve deciding whether cues to an event are in synch or out of synch, while temporal order judgments involve deciding which of the cues came first. When the cues come from different sensory modalities these judgments can be used to investigate multisensory integration in the temporal domain. However, evidence indicates that that these two tasks should not be used interchangeably as it is unlikely that they measure the same perceptual mechanism. The current experiment further explores this issue across a variety of different audiovisual stimulus types.
Participants were presented with 5 audiovisual stimulus types, each at 11 parametrically manipulated levels of cue asynchrony. During separate blocks, participants had to make synchrony judgments or temporal order judgments. For some stimulus types many participants were unable to successfully make temporal order judgments, but they were able to make synchrony judgments. The mean points of subjective simultaneity for synchrony judgments were all video-leading, while those for temporal order judgments were all audio-leading. In the within participants analyses no correlation was found across the two tasks for either the point of subjective simultaneity or the temporal integration window.
Stimulus type influenced how the two tasks differed; nevertheless, consistent differences were found between the two tasks regardless of stimulus type. Therefore, in line with previous work, we conclude that synchrony and temporal order judgments are supported by different perceptual mechanisms and should not be interpreted as being representative of the same perceptual process.

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    • "nts is the temporal order judgment ( TOJ ) task . TOJ differs from a synchrony judgment task by measuring the minimal temporal gap between the onset of a visual and an auditory stimulus for an observer to correctly determine which stimulus came first . While similar , TOJ tasks and synchrony tasks do not have the same requirements from observers ( Love et al . , 2013 ) . In performing temporal order judgment tasks , observers have a presumption that the visual and auditory stimuli are not synchronous and that one modality should occur before the other ( Van Eijk et al . , 2008 ) . A recent study reported that TOJ precision was the same between younger adults ( 18 – 29 years ) and older adults ( 70 –"
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