Abstract
The Point-Light (PL) technique, which represents a person as a cluster of point lights (PL display), is a common method to investigate the perception of body movements. Observers of such displays can identify, for instance, a performed action, the sex or the identity of the portrayed person (for a review see Blake & Shiffrar, 2007). Petrini and colleagues (2009) investigated observers' sensitivity to audio-visual temporal synchronicity by presenting PL-displays of drumming actions and found that experienced drummers had a higher sensitivity for audio-visual synchronicity than persons without expertise in the performed action. This research raises the question to which extent the perception of audio-visual temporal synchronicity is affected by stimulus characteristics, such as the complexity of the presented information. We measured perceived synchronicity for audio-visual stimuli of different complexity. During three sessions, 16 participants evaluated 84 audio-visual stimuli. Visual stimuli consisted of PL-displays of a single person. The presented movements (foot-tapping, clapping and dancing) varied in complexity. Auditory complexity ranged from a metronome (single sound) to music (multiple sounds). Audio-visual synchronicity was altered by delaying one modality with respect to the other (auditory-leading or visual-leading). Delays ranged from 80 ms to 280 ms, in steps of 40 ms. Each stimulus was presented 28 times across all sessions, and participants were asked to rate the synchronicity of each stimulus on a 6-point scale raning from asynchronous to synchronous. Results indicate an effect of movement complexity on sensitivity to audio-visual synchronicity with significantly higher thresholds for more complex relative to simpler movements. A general advantage was found for auditory-leading, relative to visual-leading stimuli. These findings extend previous research demonstrating that sensitivity to audio-visual synchronicity is affected by movement complexity. Our results contribute to the understanding of the perception of kinematic information and multisensory integration.
Meeting abstract presented at VSS 2014