title: Stability and plasticity in neural encoding of linguistically relevant pitch patterns.
abstract: While lifelong language experience modulates subcortical encoding of pitch patterns, there is emerging evidence that short-term training introduced in adulthood also shapes subcortical pitch encoding. Here we use a cross-language design to examine the stability of language experience-dependent subcortical plasticity over multiple days. We then examine the extent to which behavioral relevance induced by sound-to-category training leads to plastic changes in subcortical pitch encoding in adulthood relative to adolescence, a period of ongoing maturation of subcortical and cortical auditory processing. Frequency-following responses (FFRs), which reflect phase-locked activity from subcortical neural ensembles, were elicited while participants passively listened to pitch patterns reflective of Mandarin tones. Inexperiment 1, FFRs were recorded across three consecutive days from native Chinese-speaking (n= 10) and English-speaking (n= 10) adults. Inexperiment 2, FFRs were recorded from native English-speaking adolescents (n= 20) and adults (n= 15) before, during, and immediately after a session of sound-to-category training, as well as a day after training ceased.Experiment 1demonstrated the stability of language experience-dependent subcortical plasticity in pitch encoding across multiple days of passive exposure to linguistic pitch patterns. In contrast,experiment 2revealed an enhancement in subcortical pitch encoding that emerged a day after the sound-to-category training, with some developmental differences observed. Taken together, these findings suggest that behavioral relevance is a critical component for the observation of plasticity in the subcortical encoding of pitch.NEW & NOTEWORTHYWe examine the timescale of experience-dependent auditory plasticity to linguistically relevant pitch patterns. We find extreme stability in lifelong experience-dependent plasticity. We further demonstrate that subcortical function in adolescents and adults is modulated by a single session of sound-to-category training. Our results suggest that behavioral relevance is a necessary ingredient for neural changes in pitch encoding to be observed throughout human development. These findings contribute to the neurophysiological understanding of long- and short-term experience-dependent modulation of pitch.
authors.affiliation: Department of Communication Sciences and Disorders, The University of Texas at Austin, Austin, Texas.
authors.forename: Zilong
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Communication Sciences and Disorders, The University of Texas at Austin, Austin, Texas.
authors.forename: Rachel
authors.initials: R
authors.lastname: Reetzke
authors.affiliation: Department of Communication Sciences and Disorders, The University of Texas at Austin, Austin, Texas; bchandra@utexas.edu.|Department of Psychology, The University of Texas at Austin, Austin, Texas.|Department of Linguistics, The University of Texas at Austin, Austin, Texas.|Institute for Neuroscience, The University of Texas at Austin, Austin, Texas; and.|Institute for Mental Health Research, The University of Texas at Austin, Austin, Texas.
authors.forename: Bharath
authors.initials: B
authors.lastname: Chandrasekaran
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005793:Generalization, Psychological; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology*; D011578:Psycholinguistics; D012153:Retention, Psychology; D013057:Spectrum Analysis; D013223:Statistics as Topic; D055815:Young Adult
keywords: adolescence; auditory training; experience-dependent plasticity; frequency-following response; pitch encoding