Humansimian correspondence in the early cortical processing of multisensory cues
Recent findings in both monkeys and humans indicate that multisensory convergence occurs in low-level cortical structures generally believed to be unisensory in function. There is also evidence that multisensory convergence in higher-order regions occurs at very short post-stimulus latencies. Both types of convergence are of interest as they represent substrates for multisensory interactions in early cortical processing. This paper reviews the correspondence between specific findings in humans and monkeys, focusing on two areas, posterior auditory association cortex and posterior parietal visual association cortex. In each case we examine evidence for low-level and/or early multisensory convergence in humans, and then examine the results of direct physiological investigation of homologous effects in macaque monkeys. The latter allow a precise physiological and anatomical description of the effects noted in human subjects to be found. We then consider the functional implications of multisensory integration in early and low-level sensory processing, both in relation to our basic hierarchical model of cortical processing and in relation to our understanding of multisensory processes in perception. We end by considering the importance of humansimian homology in the study of the multisensory components of primate (human and monkey) communication.
multisensory convergence temporal coincidence feedback current source density erp