Temporal binding favours the early phase of colour changes, but not of motion changes, yielding the colour–motion asynchrony illusion

Abstract

How our binding mechanism judges features as simultaneous remains mysterious. When moving dots alternate in colour and motion direction, reports of the perceived colour and motion pairing reveal an asynchrony in temporal binding: The motion change best precedes the associated colour change by about 150 ms. Here the durations of the motion and colour were independently varied. Regardless of motion duration, pairing reports were most consistent when the midpoint of the motion interval occurred at a particular time relative to the colour, suggesting no differential weighting of early versus late portions of the motion interval. In contrast, as colour duration increased, the best time of its midpoint shifted later, indicating that it is best to align the early part of the colour with the motion. Thus, the colour–motion asynchrony phenomenon appears to result from the binding process favouring the early phase of the colour but not the early part of the motion.

Keywords:

• Binding
• Asynchrony
• Dynamics
• Perception

Acknowledgements

I thank Daniel Linares for helpful discussion, Alex White, Colin Clifford, and Ed Vul for comments, and Australian Research Council grant DP0772037 for support.

Notes

¹A demonstration of similar stimuli is available at http://www.psych.usyd.edu.au/staff/alexh/research/asynchronyVSS06/