Coding of auditory-stimulus identity in the auditory non-spatial processing stream.

The neural computations that underlie the processing of auditory-stimulus identity are not well understood, especially how information is transformed across different cortical areas. Here, we compared the capacity of neurons in the superior temporal gyrus (STG) and the ventrolateral prefrontal cortex (vPFC) to code the identity of an auditory stimulus; these two areas are part of a ventral processing stream for auditory-stimulus identity. Whereas the responses of neurons in both areas are reliably modulated by different vocalizations, STG responses code significantly more vocalizations than those in the vPFC. Together, these data indicate that the STG and vPFC differentially code auditory identity, which suggests that substantial information processing takes place between these two areas. These findings are consistent with the hypothesis that the STG and the vPFC are part of a functional circuit for auditory-identity analysis.