A diagram of non-human primate AC model, and a possible human homologue. (a) Non-human primate AC model. Note that the exact arrangement of tonotopic gradients may not be exactly as parallel to area boundaries as in this simplified presentation. However, in general, there are three core areas (auditory area 1, A1; rostral, R; rostrotemporal, RT) include roughly mirror-symmetric tonotopic gradients extending to the lateral (rostrotemporolateral, RTL; anterolateral, AL; middle lateral, ML; caudolateral, CL) and medial (rostrotemporomedial, RTM; rostromedial, RM; middle medial, MM; caudomedial, CM) belt cortices. (b) The corresponding human AC hypothesis, modified based on previous human fMRI (Humphries et al., 2010; Woods et al., 2010) and cytoarchitectonic studies (Hackett et al., 2001; Rivier and Clarke, 1997), is shown on a flattened patch of superior temporal cortex. Anatomical regions: Heschl’s gyrus (HG), planum temporale (PT), superior temporal gyrus (STG), and planum polare (PP).