Reflection of the effectiveness of heterosensory integration in measures of event-linked potentials.

The phenomenon of bimodal event-linked potential mismatch and summation of unimodal responses were used to study the relationship between mismatch amplitude and the effectiveness of visual-auditory integration. The effectiveness of integration was assessed in terms of the extent to which experimental measures approached the parameters of the "ideal observer." The greater the effectiveness of integration, the greater the focus of mismatch shifted from the occipital to the frontal areas of the cortex. The greatest correlation between mismatch amplitude and the effectiveness of visual-auditory integration was seen in the left frontal cortex.