Putting causality into context: Causal capture escapes the visual adaptation of causality

Abstract

Results from psychophysical studies using visual adaptation suggest that launch detectors in the visual system underlie the perception of causality in simple visual events. These detectors respond to events in which one stimulus collides with another stimulus (i.e., a launch), and do not respond to events where one stimulus passes over another (i.e., a pass). Prolonged visual adaptation to launches significantly reduces observers propensity to see causal launches at the same retinotopic location. This finding could be taken to indicate that launch detectors are necessary for the local detection of causal launches. However, contextual events--that are spatially separated from the test event location--shift observers perception of a causal relation in the direction of the type of contextual event (Scholl & Nakayama, 2002), providing evidence for spatial integration beyond a specific retinotopic location. Here, we used visual adaptation as a tool to investigate whether the contextual influence on causal perception relies on local launch detectors. Before and after adaptation, we determined the proportion of reported launches in ambiguous test events in the presence of no context, launch context, and pass context events. We hypothesized that if the contextual influence relies on (unadapted) local launch detectors, then visual adaptation should affect the contextual influence on causal perception. Before adaptation, a launch-context event increased the proportion of reported launches (while a pass context event decreased it). Visual adaptation to launches significantly decreased the proportion of reported launches in no-context trials, but did not affect perceptual reports in no-context trials. In fact, contextual influences, expressed relative to no-context trials, emerged strongly after adaptation. This result suggests that context effects override strong negative aftereffects from adaptation, indicating that contextual influences operate at a level that bypasses the local launch detector at the adapted location.