The effect of looming and receding sounds on the in-depth perception of point-light figures
Ben Schouten, Elke Moyens, Anna Brooks, Rick van der Zwan, Karl Verfaillie
Poster
Last modified: 2008-05-13
Abstract
Being highly sensitive to looming (biological) entities could provide a substantial selection advantage: A sound with a rising intensity or an increasing visual projection of an object or animal can signal movement towards the observer. The auditory system seems to provide us with a perceptual bias for such behaviourally relevant stimuli (Neuhoff, 1998, Nature). In the visual modality, Vanrie et al (2004, Perception) found that even though the orthogonal 3D to 2D projection of a point-light walker (plw) is perceptually bistable, it induces the convincing percept of a walker facing the viewer in about 80% of the cases. The current research explores to what extent a looming or receding sound as compared to a stationary sound and no sound can affect the in-depth interpretation of a plw. To allow effects in both directions the perceived in-depth orientation of the plw was manipulated from convincingly looming to convincingly receding with perspective cues. Looming, receding, and stationary sounds respectively consisted of ticks of increasing, decreasing, or stable intensity, synchronized with the footsteps of the plw. Results suggest that a looming and receding sound can alter the in-depth interpretation of a point-light walker. However, this effect appeared not to be mandatory.