Abstract
Perceiving the sensory consequences of action accurately is essential for appropriate interaction with our physical and social environments. Successful interaction with the environment requires perception not only of the nature of our action outcomes (e.g., somatosensation on the fingertips when grasping a cup), but also crucially, the onset and duration of those outcomes. Nevertheless, our perception is rarely veridical. In the present series of experiments, we examine this problem by focusing on how movement influences the perceived duration of sensory outcomes congruent with action. In Experiment 1, participants were required to perform a lifting movement with either their index or middle finger. A short (104 – 296 ms) target vibratory tactile stimulus was presented to the moving or stationary finger, followed by a second reference vibration (200 ms). Participants judged which was of longer duration, and the point of subjective equivalence (PSE) was derived from the resulting psychometric function. In Experiments 2 and 3, participants judged observed avatar finger movements, congruent or incongruent with their own concurrent actions. In all experiments, target events were perceived as longer when the perceived event was congruent with movement. Interestingly, visual effects did not differ as a function of stimulus perspective (first or third person) or spatial location (left / right location of avatar lift relative to participant lift). These results indicate that action modulates the perceived duration of sensory events congruent with action, which may result from predictive mechanisms operating for action selection and error correction. The influence of these biases on tightly time-locked action control and social perception must be considered, given that we may be in contact with grasped objects for less time than we realize and handshakes may be briefer than we believe.
Meeting abstract presented at VSS 2014