Computational Models of Inferior Colliculus Neurons

The inferior colliculus (IC), the principal auditory nucleus in the midbrain, occupies a key position in the auditory system. It receives convergent input from most of the auditory nuclei in the brain stem, and in turn, projects to the auditory forebrain (Winer and Schreiner 2005). The IC is therefore a major site for the integration and reorganization of the different types of auditory information conveyed by largely parallel neural pathways in the brain stem, and its neural response properties are accordingly very diverse and complex (Winer and Schreiner 2005). The function of the IC has been hard to pinpoint. The IC has been called the “nexus of the auditory pathway” (Aitkin 1986), a “shunting yard of acoustical information processing” (Ehret and Romand 1997), and the locus of a “transformation [that] adjusts the pace of sensory input to the pace of behavior” (Casseday and Covey 1996). The vague, if not metaphorical, nature of these descriptions partly reflects the lack of a quantitative understanding of IC processing such as that which has emerged from computational studies of the cochlear nucleus (Voigt, Chapter 3) and superior olivary complex (Colburn, Chapter 4).