The role of the auditory brainstem in processing linguistically-relevant pitch patterns.
Historically, the brainstem has been neglected as a part of the brain involved in language processing. We review recent evidence of language-dependent effects in pitch processing based on comparisons of native vs. nonnative speakers of a tonal language from electrophysiological recordings in the auditory brainstem. We argue that there is enhancing of linguistically-relevant pitch dimensions or features well before the auditory signal reaches the cerebral cortex. We propose that long-term experience with a tone language sharpens the tuning characteristics of neurons along the pitch axis with enhanced sensitivity to linguistically-relevant, rapidly changing sections of pitch contours. Though not specific to a speech context, experience-dependent brainstem mechanisms for pitch representation are clearly sensitive to particular aspects of pitch contours that native speakers of a tone language have been exposed to. Such experience-dependent effects on lower-level sensory processing are compatible with more integrated, hierarchically organized pathways to language and the brain.
Department of Speech Language Hearing Sciences, Purdue University, 1353 Heavilon Hall, 500 Oval Drive, West Lafayette, IN 47907-2038, USA.
Ananthanarayan
A
Krishnan
Jackson T
JT
Gandour
D000818:Animals; D001933:Brain Stem / Q000502:physiology*; D006801:Humans; D008037:Linguistics; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology; D010898:Pitch Perception / Q000502:physiology*