Multichannel recordings of the human brainstem frequency-following response: Scalp topography, source generators, and distinctions from the transient ABR.

Multichannel recordings of the human brainstem frequency-following response: Scalp topography, source generators, and distinctions from the transient ABR.
Hear Res. 2015 Feb 5;
Authors: Bidelman GM
Abstract
Brainstem frequency-following responses (FFRs) probe the neural transcription of speech/music, auditory disorders, and plasticity in subcortical auditory function. Despite clinical and empirical interest, the response's neural basis remains poorly understood. The current study aimed to more fully characterize functional properties of the human FFR (topography, source locations, generation). Speech-evoked FFRs were recorded using a high-density (64 channel) electrode montage. Source dipole modeling and 3-channel Lissajous analysis was used to localize the most likely FFR generators and their orientation trajectories. Additionally, transient auditory brainstem responses (ABRs), recorded in the same listeners, were used to predict FFRs and test the long-held assumption that the sustained potential reflects a series of overlapping onset responses. Results showed that FFRs were maximal at frontocentral scalp locations with obliquely oriented sources from putative generators in the midbrain (i.e., upper brainstem). Comparisons between derived and actual recordings revealed the FFR is not a series of repeated ABR wavelets and thus, represents a functionally distinct brainstem response. FFRs recorded at temporal electrode sites showed lar...

Source: Hearing Research - February 5, 2015 Category: Audiology Authors: Bidelman GM Tags: Hear Res Source Type: research