Compression of Auditory Space during Forward Self-Motion

<div><h3>Background</h3><p>Spatial inputs from the auditory periphery can be changed with movements of the head or whole body relative to the sound source. Nevertheless, humans can perceive a stable auditory environment and appropriately react to a sound source. This suggests that the inputs are reinterpreted in the brain, while being integrated with information on the movements. Little is known, however, about how these movements modulate auditory perceptual processing. Here, we investigate the effect of the linear acceleration on auditory space representation.</p> <h3>Methodology/Principal Findings</h3><p>Participants were passively transported forward/backward at constant accelerations using a robotic wheelchair. An array of loudspeakers was aligned parallel to the motion direction along a wall to the right of the listener. A short noise burst was presented during the self-motion from one of the loudspeakers when the listener’s physical coronal plane reached the location of one of the speakers (null point). In Experiments 1 and 2, the participants indicated which direction the sound was presented, forward or backward relative to their subjective coronal plane. The results showed that the sound position aligned with the subjective coronal plane was displaced ahead of the null point only during forward self-motion and that the magnitude of the displacement increased with increasing the acceleration. Experiment 3 investigated the structure of the auditory space in the traveling direction during forward self-motion. The sounds were presented at various distances from the null point. The participants indicated the perceived sound location by pointing a rod. All the sounds that were actually located in the traveling direction were perceived as being biased towards the null point.</p> <h3>Conclusions/Significance</h3><p>These results suggest a distortion of the auditory space in the direction of movement during forward self-motion. The underlying mechanism might involve anticipatory spatial shifts in the auditory receptive field locations driven by afferent signals from vestibular system.</p> </div

Transfer effects of playing a virtual three-dimensional auditory game: Influences on the performance in a communication task and a collision avoidance task

Presented at the 12th International Conference on Auditory Display (ICAD), London, UK, June 20-23, 2006.We investigated the transfer effects of playing an auditory game with a virtual auditory display (VAD) on various auditory skills in daily life situations. To measure those effects, all blindfolded participants performed a communication task and a collision avoidance task on the first day. They were asked to perform the same tasks two weeks later. Participants of the training condition were asked to play the VAD game for seven days (30 min/day) for two weeks, whereas the control group did not play the game within that period. Results of playing the VAD game revealed that the number of face-contacts in the communication task increased significantly. In contrast, no difference was detectable in the subjectively rated levels of tension during the communication task between the two conditions. Furthermore, results showed that playing the VAD game altered the participants' avoidance behaviors. Therefore, we can conclude that the effects of playing the VAD game transfer to communication behaviors in social interaction and to avoidance behaviors from approaching objects in a real environment

Inhibition of target detection in apparent motion trajectory

Jiro Gyoba Letter discrimination performance is degraded when a letter is presented within an apparent motion (AM) trajectory of a spot. This finding suggests that the internal representation of AM stimuli can perceptually interact with other stimuli. In this study, we demonstrated that AM interference could also occur for pattern detection. We found that target (Gabor patch) detection performance was degraded within an AM trajectory. Further, this AM interference weakened when the differences in orientation between the AM stimuli and target became greater. We also revealed that AM interference occurred for the target with spatiotemporally intermediate orientations of the inducers that changed their orientation during AM. In contrast, the differences in phase among the stimuli did not affect the occurrence of AM interference. These findings suggest that AM stimuli and their internal representations affect lower visual processes involved in detecting a pattern in the AM trajectory and that the internal object representation of an AM stimulus selectively reflects and maintains the stimulus attribute