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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Available from: Karin Petrini, Oct 04, 2015
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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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    ABSTRACT: Previous research provides conflicting evidence regarding whether older adults have altered tolerance to timing differences between auditory and visual events. We examine the potential impact of age-related unisensory decline on audiovisual synchrony perception. Fifteen younger (21-32 years) and 13 older (60-72 years) adults participated. To assess unisensory sensitivity, visual Gabor contrast detection thresholds and auditory masked tone pip detection thresholds were measured. Four multisensory conditions were then tested: suprathreshold and near-threshold stimuli (based on individual unisensory psychometric functions), each tested with a masked tone pip stimuli at 0.5 and 4 kHz sound frequencies. Two audiovisual pairs (one synchronous, the other asynchronous) were presented in a two-interval forced-choice procedure, with observers identifying the interval containing the asynchronous stimulus. Older adults required a larger physical asynchrony to perceive the stimuli as asynchronous, particularly for low frequency sounds. Our results demonstrate that the impact of age on audiovisual synchrony perception cannot be explained by decline in unisensory sensitivity alone.
    Journal of Vision 09/2014; 14(11). DOI:10.1167/14.11.13 · 2.39 Impact Factor
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    • "However, in a temporal order judgment task, Fiacconi et al. (2013) failed to find the same age effect. Love et al. (2013) and van Eijk et al. (2008) have compared the results from audiovisual synchrony judgment and temporal order judgment tasks and suggest that the two tasks tap into different underlying neural mechanisms for temporal perception (van Eijk et al., 2008; Love et al., 2013). Audiovisual synchrony judgment gives a more accurate measure of the perception of subjective simultaneity, whereas temporal order judgment provides a better measure of the smallest audiovisual asynchrony detectable by the perceptual system (van Eijk et al., 2008). "
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    Frontiers in Aging Neuroscience 08/2014; 6(10):226. DOI:10.3389/fnagi.2014.00226 · 4.00 Impact Factor
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    • "To further investigate whether musical expertise shapes temporal binding of non-music stimuli, we presented 21 musicians and 20 non-musicians participants with natural speech, intelligible sinewave analogs of speech, and piano music stimuli at 13 audiovisual stimulus onset asynchronies (±360, ±300 ±240, ±180, ±120, ±60, and 0 ms) (Dixon and Spitz, 1980; Alais and Burr, 2003; Grant et al., 2004; Zampini et al., 2005; Vatakis and Spence, 2006a,b, 2007, 2008a,b; van Wassenhove et al., 2007; Love et al., 2013). On each trial, participants judged the audiovisual synchrony of natural speech, sinewave speech, and piano music stimuli. "
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    ABSTRACT: This psychophysics study used musicians as a model to investigate whether musical expertise shapes the temporal integration window for audiovisual speech, sinewave speech, or music. Musicians and non-musicians judged the audiovisual synchrony of speech, sinewave analogs of speech, and music stimuli at 13 audiovisual stimulus onset asynchronies (±360, ±300 ±240, ±180, ±120, ±60, and 0 ms). Further, we manipulated the duration of the stimuli by presenting sentences/melodies or syllables/tones. Critically, musicians relative to non-musicians exhibited significantly narrower temporal integration windows for both music and sinewave speech. Further, the temporal integration window for music decreased with the amount of music practice, but not with age of acquisition. In other words, the more musicians practiced piano in the past 3 years, the more sensitive they became to the temporal misalignment of visual and auditory signals. Collectively, our findings demonstrate that music practicing fine-tunes the audiovisual temporal integration window to various extents depending on the stimulus class. While the effect of piano practicing was most pronounced for music, it also generalized to other stimulus classes such as sinewave speech and to a marginally significant degree to natural speech.
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