Dissociations of temporal-order and synchrony judgments: Revisited
Single Paper Presentation

Shin'ya Nishida
NTT Communication Science Labs

Waka Fujisaki
NTT Communication Science Labs

     Abstract ID Number: 79
     Full text: Not available
     Last modified: March 23, 2007
     Presentation date: 07/07/2007 11:30 AM in Quad General Lecture Theatre
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Abstract
Using a synchrony-asynchrony discrimination task, we found that the accuracy of temporal judgment was worst for an audio-visual (AV) pair, almost the same or slightly better for a visuo-tactile (VT) pair, and still better for an audio-tactile (AT) pair [though not as good as a within-tactile (TT) pair for the majority of participants] (Fujisaki & Nishida, IMRF2007). Here we measured the temporal accuracies of the same set of stimuli (single pulse) using more subjective tasks: a yes-no synchrony judgment and a temporal-order judgment (TOJ). The thresholds obtained with the synchrony judgment agreed well with those obtained with the synchrony-asynchrony discrimination task. In comparison with these synchrony judgments, TOJ was affected less by the stimulus type. It however was not perfectly stimulus-type independent (cf, Hirsh & Sherrick, 1961; Poppel, 1997). To be more specific, although the average data showed the same order of threshold magnitudes (AV>VT>AT>TT), their difference was relatively small (AV/TT=~2 as compared to ~4 for the synchrony tasks) and variable among participants. We also found another, and more dramatic dissociation — hand crossing severely impaired TT judgments for the TOJ (Yamamoto et al., 2001), but not for the synchrony judgment at all. The observed dissociations between synchrony judgments and TOJ can be partially, but not exclusively, ascribed to additional labeling processing required for TOJ.