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Interaction of perceptual grouping and crossmodal temporal capture in tactile apparent-motion.

Chen L, Shi Z, Müller HJ - PLoS ONE (2011)

Bottom Line: The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping.This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation.These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Key Laboratory of Machine Perception (Ministry of Education), Peking University, Beijing, P. R. China.

ABSTRACT
Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture" visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs--one short (75 ms), one long (325 ms)--were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects.

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Normalized phase durations of tactile apparent motion in Experiment 2.Normalized phase durations (and associated standard errors) of tactile apparent motion as a function of audiotactile SOA with a shifted full-pairing audiotactile stream.
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pone-0017130-g003: Normalized phase durations of tactile apparent motion in Experiment 2.Normalized phase durations (and associated standard errors) of tactile apparent motion as a function of audiotactile SOA with a shifted full-pairing audiotactile stream.

Mentions: Figure 3 presents the mean phase durations for “initial-direction” and “reverse-direction” responses as a function of the (variable) audiotactile SOA. A repeated-measures ANOVA for the “initial-direction” responses revealed the main effect of audiotactile SOA to be significant, F(2,20) = 11.66, p<0.01 (F(2,20) = 7.215, p<0.01, for the “reverse direction”). Bonferroni-corrected pairwise comparisons showed that for both “initial-direction” and “reverse-direction” responses, the mean phase durations differed significantly between the 75-ms and the 325-ms SOA, ps<0.05. With an audiotactile SOA of 75 ms, the response pattern was similar to that in Experiment 1, that is, characterized by dominance of “initial direction”. However, the dominant motion direction was changed to “reverse direction” when the audiotactile SOA was increased to 325 ms. The differential dominance patterns of tactile apparent motion between these two conditions is the most interesting finding of Experiment 2, which demonstrates that crossmodal grouping can strongly influence the crossmodal temporal integration.


Interaction of perceptual grouping and crossmodal temporal capture in tactile apparent-motion.

Chen L, Shi Z, Müller HJ - PLoS ONE (2011)

Normalized phase durations of tactile apparent motion in Experiment 2.Normalized phase durations (and associated standard errors) of tactile apparent motion as a function of audiotactile SOA with a shifted full-pairing audiotactile stream.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3044160&req=5

pone-0017130-g003: Normalized phase durations of tactile apparent motion in Experiment 2.Normalized phase durations (and associated standard errors) of tactile apparent motion as a function of audiotactile SOA with a shifted full-pairing audiotactile stream.
Mentions: Figure 3 presents the mean phase durations for “initial-direction” and “reverse-direction” responses as a function of the (variable) audiotactile SOA. A repeated-measures ANOVA for the “initial-direction” responses revealed the main effect of audiotactile SOA to be significant, F(2,20) = 11.66, p<0.01 (F(2,20) = 7.215, p<0.01, for the “reverse direction”). Bonferroni-corrected pairwise comparisons showed that for both “initial-direction” and “reverse-direction” responses, the mean phase durations differed significantly between the 75-ms and the 325-ms SOA, ps<0.05. With an audiotactile SOA of 75 ms, the response pattern was similar to that in Experiment 1, that is, characterized by dominance of “initial direction”. However, the dominant motion direction was changed to “reverse direction” when the audiotactile SOA was increased to 325 ms. The differential dominance patterns of tactile apparent motion between these two conditions is the most interesting finding of Experiment 2, which demonstrates that crossmodal grouping can strongly influence the crossmodal temporal integration.

Bottom Line: The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping.This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation.These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Key Laboratory of Machine Perception (Ministry of Education), Peking University, Beijing, P. R. China.

ABSTRACT
Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture" visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs--one short (75 ms), one long (325 ms)--were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects.

Show MeSH