Abstract
In a temporal order judgment (TOJ) task, observers view asynchronously presented pairs of short-duration visual objects and report which one occurred first. Typical stimuli are ultra-brief (temporally broadband) rectangular pulses, and thresholds can approach 3 ms when a pair of identical pulses is used (Westheimer & McKee, 1977).
A different stimulus configuration results in a striking misperception of temporal order. Our observers view pulses with a narrower temporal bandwidth (e.g. temporal Gabors) and perform TOJ for stimulus pairs with differing temporal frequency content. This manipulation produces bias in the perceived asynchrony between high and low temporal frequency stimuli, with high temporal frequencies appearing delayed up to ∼100 ms. We believe these effects occur early in the magnocellular visual pathway, and present a model that shows how the biphasic temporal impulse responses of magnocellular ganglion cells could account for our data. We have also designed a novel motion illusion (analogous the Campbell-Robson contrast sensitivity chart) in order to allow viewers to directly experience the magnitude of this perceptual asynchrony.
Westheimer, G., & McKee, S. P. (1977). Perception of temporal order in adjacent visual stimuli. Vision Research, 17(8), 887-892.