Differential sensitivity to changes in pitch acceleration in the auditory brainstem and cortex

- Cortical (CPR) and brainstem (FFR) responses to changes in pitch acceleration rate.
- Tone 2 elicits larger responses than Linear at both levels of cortex and brainstem.
- Relative changes in magnitude between stimuli differ across levels of the brain.
- Pb-Nb has larger magnitude difference between Tone 2 & Linear than Na-Pb or FFR.
- CPR transient components are differentially sensitive to pitch acceleration rate.

The cortical pitch-specific response (CPR) is differentially sensitive to pitch contours varying in rate of acceleration-time-variant Mandarin Tone 2 (T2) versus constant, linear rising ramp (Linear)-as a function of language experience (Krishnan, Gandour, & Suresh, 2014). CPR and brainstem frequency following response (FFR) data were recorded concurrently from native Mandarin listeners using the same stimuli. Results showed that T2 elicited larger responses than Linear at both cortical and brainstem levels (CPR: Na-Pb, Pb-Nb; FFR). However, Pb-Nb exhibited a larger difference in magnitude between T2 and Linear than either Na-Pb or FFR. This finding highlights differential weighting of brain responses elicited by a specific temporal attribute of pitch. Consistent with the notion of a distributed, integrated hierarchical pitch processing network, temporal attributes of pitch are differentially weighted by subcortical and cortical level processing.

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