State-dependent encoding of sound and behavioral meaning in a tertiary region of the ferret auditory cortex

In higher sensory cortices, there is a gradual transformation from sensation to perception and action. In the auditory system, this transformation is revealed by responses in the rostral Ventral Posterior field (VPr), a tertiary area in ferret auditory cortex, which shows long-term learning in trained compared to naïve animals, arising from selectively enhanced responses to behaviorally relevant target stimuli. This enhanced representation is further amplified during active performance of spectral or temporal auditory discrimination tasks. VPr also shows sustained short-term memory activity after target stimulus offset, correlated with task-response timing and action. These task-related changes in auditory filter properties enable VPr neurons to quickly and nimbly switch between different responses to the same acoustic stimuli, reflecting either spectrotemporal properties, timing or behavioral meaning of the sound. Furthermore, they demonstrate an interaction between dynamics of long-term learning and short-term attention as incoming sound is selectively attended, recognized and translated into action.