Abstract
We can perceive not only low-level features of events such as color and motion, but also seemingly higher-level properties such as causality. Perhaps the best example of causal perception is the 'launching effect': one object (A) moves toward a stationary second object (B) until they are adjacent, at which point A stops and B starts moving in the same direction. Beyond the kinematics of these motions themselves, and regardless of any higher-level beliefs, this display induces a vivid impression of causality, wherein A is seen to cause B's motion. Do such percepts reflect a unitary category of visual processing, or might there be multiple distinct forms of causal perception? On one hand, the launching effect is often simply equated with causal perception more broadly. On the other hand, researchers have sometimes described other phenomena such as 'braking' (in which B moves much slower than A) or 'triggering' (in which B moves much faster than A). We used psychophysical methods to determine whether these labels really carve visual processing at its joints, and how they relate to each other. Previous research demonstrated a form of retinotopically specific adaptation to causality: exposure to causal launching makes subsequent ambiguous events in that same location more likely to be seen as non-causal 'passing'. We replicated this effect, and then went on to show that exposure to launching also yields retinotopically specific adaptation for subsequent ambiguous braking displays, but not for subsequent ambiguous triggering displays. Furthermore, exposure to triggering not only yielded retinotopically specific adaptation for subsequent ambiguous triggering displays, but also for subsequent ambiguous launching displays. Collectively, these results reveal that there is more to causal perception than just the launching effect: visual processing distinguishes some (but not all) types of causal interactions.
Meeting abstract presented at VSS 2016