The effects of subthreshold synchrony on the perception of simultaneity
We aimed to examine the effects of subthreshold synchrony and asynchrony on the perception of simultaneity. We rendered simultaneous or asynchronous luminance changes below detection thresholds by embedding them in a sequence of rapidly onsetting flankers. Still, simultaneity of subthreshold luminance changes can influence decisions concerning the simultaneity of clearly visible changes in luminance: across a range of very brief target SOAs, subthreshold synchrony was found to increase the tendency to report ‘simultaneity’, although simultaneity thresholds themselves remained largely uninfluenced. These effects are discussed in terms of the early synchronization of sensory mechanisms and the extent to which this pattern of synchronization influences the perception of relations between events in time.
KeywordsPsychometric Function Background Luminance Luminance Change Target Luminance Simultaneity Judgment
We are grateful for suggestions from Joe Krummenacher during the formulation of our original research questions, to Ulrich Ansorge, Michael Herzog and one anonymous reviewer for their helpful suggestions on the improvement of the manuscript. This research was conducted at the LMU in Munich and was supported by German Research Council (DFG) project grant EL 248/1 to MAE.
- Brecher, G. A. (1932). Die Entstehung und biologische Bedeutung der subjectktiven Zeiteinheit—des Momentes. Zeitschrift für vergleichende Physiologie, 18, 204–243.Google Scholar
- Klein, S. A. (2001). Measuring, estimating, and understanding the psychometric function: A commentary. Perception & Psychophysics, 63 (8), 1421–1455.Google Scholar