Sensitivity of temporal order judgments with repeated stimuli
Last modified: 2013-05-05
Abstract
Precision in bimodal temporal order judgments is mainly limited by the variability of a central decision mechanism (Sternberg and Knoll, 1973). Ley et al. (2009) have shown that precision could be increased if two bimodal stimuli are presented contemporarily. Here we want to investigate whether such an increase in precision can be obtained if the same bimodal stimulus is repeated at a later time.
Participants reported the temporal order of an audiovisual pair, or multiple identical pairs presented in a regular sequence (ISI 400ms). Trials with different sequence lengths and asynchrony were presented interleaved within one block. Sensitivity increases if two audiovisual pairs are presented as compared to only one. Such an increase is indistinguishable from statistical optimality. Surprisingly however, sensitivity with three and four repeated audiovisual stimuli is suboptimal and in fact identical to the sensitivity obtained with two stimuli.
In a second experiment, two audiovisual pairs were presented in succession with a slight difference in asynchrony (60ms). Sensitivity is still close to optimal in this case and the point of subjected simultaneity indicates that the two audiovisual stimuli have been given similar weight in the judgment.
These results indicate that precision in temporal order judgments can benefit from stimulus repetition, but the improvement is limited to two repetitions. Such a limit can be related to the temporal integration characteristics of the decision mechanism.
Participants reported the temporal order of an audiovisual pair, or multiple identical pairs presented in a regular sequence (ISI 400ms). Trials with different sequence lengths and asynchrony were presented interleaved within one block. Sensitivity increases if two audiovisual pairs are presented as compared to only one. Such an increase is indistinguishable from statistical optimality. Surprisingly however, sensitivity with three and four repeated audiovisual stimuli is suboptimal and in fact identical to the sensitivity obtained with two stimuli.
In a second experiment, two audiovisual pairs were presented in succession with a slight difference in asynchrony (60ms). Sensitivity is still close to optimal in this case and the point of subjected simultaneity indicates that the two audiovisual stimuli have been given similar weight in the judgment.
These results indicate that precision in temporal order judgments can benefit from stimulus repetition, but the improvement is limited to two repetitions. Such a limit can be related to the temporal integration characteristics of the decision mechanism.
Keywords
simultaneity perception; psychophysics; bayesian modelling; tempora order judgments
References
Sternberg, S., and Knoll, R. (1973). The perception of temporal order: Fundamental issues and a general model. In S. Kornblum (Ed.) Attention and performance IV. New York: Academic Press. Pp. 629-685.
Ley, I., Haggard, P., and Yarrow, K. (2009). Optimal integration of auditory and vibrotactile information for judgments of temporal order. J Exp Psychol Human 35, 1005–1019.