Temporal processing in the central auditory system

The sensation of time is necessary for learning and behavior such as communication, sensory-motor processing, or memorization. As no dedicated sensory system for time exists, its perception must have an intimate connection to (the experience of) sensory features of an event, such as the duration of a sound. One way to study time perception is therefore to understand how sound duration is computed, or how a sound’s beginning (onset) or end (offset) are coded and perceived. In this study, we asked whether cortical offset responses play a role in sound duration perception, and what circuit mechanisms drive them. Using behavioral tasks combined with optogenetic manipulations, our results revealed that experimentally minimizing auditory cortical offset responses decreases the mouse performance to detect sound termination. By combining in vivo electrophysiology in the auditory cortex and thalamus of awake mice, we also demonstrated that cortical offset responses are not only inherited from the periphery but also amplified and generated de novo. Finally, we showed that offset responses code more than silence, including relevant changes in sound trajectories. Together, our results reveal the importance of cortical offset responses in encoding sound duration, and by extension, temporal processing and time sensation.