Neural Correlates Of Pitch And Roughness

(Cont.) Roughness, the sensation of temporal envelope fluctuations in the range of 20-200 Hz, is often equated with sensory dissonance. Here we examine IC neural responses for correlates of sensory dissonance. We show that sensory dissonance correlates with discharge rate fluctuations of all IC neurons and with average rates of a subset of IC neurons which only respond at the onset of pure-tones. Results indicate that IC neurons are specifically important for the coding of the temporal envelope. Our findings illustrate the complexity and specificity of auditory neural processing in the brainstem and midbrain and show that percepts generally considered to be high order, such as the dissonance of musical intervals, have direct correlates in neural responses in the midbrain. More generally they show that the auditory system performs processing important for music at multiple time scales.