In the last 4 years, we have developed a partnership between dance and neuroscience to study the relationships between body space in dance and the surrounding space, and the link between movement and audition as experienced by the dancer. The opportunity to work with a dancer/choreographer, an expert in movement, gives neuroscientists better access to the significance of the auditory-motor loop and its role in perception of the surrounding space. Given that a dancer has a very strong sense of body ownership (probably through a very accurate dynamic body schema) ( Walsh et al. 2011 ), she is an ideal subject to investigate the feeling of controlling one's own body movements, and, through them, events in the external environment ( Moore et al. 2009 , Jola et al in press). We conducted several work sessions, which brought together a choreographer/dancer, a neuroscientist, a composer, and two researchers in acoustics and audio signal processing. These sessions were held at IRCAM (Institute for Research and Coordination Acoustic/Music, Paris) in a variable-acoustics concert hall equipped with a Wave Field Synthesis (WFS) sound reproduction system and infrared cameras for motion capture. During these work sessions, we concentrated on two specific questions: 1) is it possible to extend the body space of the dancer through auditory feedback ( Maravita and Iriki 2004 )? and 2) can we alter the dancer's perception of space by altering perceptions associated with movements? We used an interactive setup in which a collection of pre-composed sound events (individual sounds or musical sentences) could be transformed and rendered in real time according to the movements and the position of the dancer, that were sensed by markers on her body and detected by a motion tracking system. The transformations applied to the different sound components through the dancer's movement and position concerned not only musical parameters such as intensity, timbre, etc. but also the spatial parameters of the sounds. The technology we used allowed us to control their trajectory in space, apparent distance and the sound reverberation ambiance. We elaborated a catalogue of interaction modes with auditory settings that changed according to the dancer's movements. An interaction mode is defined by different mappings of position, posture or gesture of the dancer to musical and spatial parameters. For instance, a sound event may be triggered if the dancer is within a certain region or if she performs a predefined gesture. More elaborated modes involved the modulation of musical parameters by continuous movements of the dancer. The pertinence at a perceptive and cognitive level of the catalogue of interactions has been tested throughout the sessions. We observed that the detachable markers could be used to create a perception of extended body space, and that the performer perceived the stage space differently according to the auditory feedback of her action. The dancer reported that each experience with the technology shed light on her need for greater awareness and exploration of her relationships with space. Real-time interactivity with sound heightened her physical awareness – as though the stage itself took on a role and became another character.
The effect of real-time auditory feedback on learning new characters
