Experiment 2: Audio-visual velocity coherence

In experiment 2, we applied a 2x2-design in which both, the visual and the auditory part of a simultaneous and directionally congruent motion, could independent of one another either be fast or slow. By this, we could compare audio-visual velocity signals which vary in the strength of the auditory as well as the visual motion component. If auditory information is integrated throughout all conditions, we’d expect subjects to require less contrast to perform pursuit. This should be reflected in lower PSE values in the fast auditory conditions (main effect). If, however, integration depends on the coherence of both velocities, we’d expect an interaction in the sense that a pursuit benefit only appears if both components are either fast or slow (interaction). Additionally, we want to test if subjects first have to learn the integration of auditory and visual information. We thus split up the experiment in three consecutive sessions. If integration requires learning, the benefit should become more prominent during the later sessions.