Frequency-Following Responses to Speech Sounds Are Highly Conserved across Species and Contain Cortical Contributions.
G Nike Gnanateja, Kyle Rupp, Fernando Llanos, Madison Remick, Marianny Pernia, Srivatsun Sadagopan, Tobias Teichert, Taylor J Abel, Bharath Chandrasekaran
Author Information
G Nike Gnanateja: Department of Communication Sciences and Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania 15260. ORCID
Kyle Rupp: Department of Neurological Surgery, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213.
Fernando Llanos: Department of Linguistics, The University of Texas at Austin, Austin, Texas 78712.
Madison Remick: Department of Neurological Surgery, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213.
Marianny Pernia: Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15261.
Srivatsun Sadagopan: Department of Communication Sciences and Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania 15260. ORCID
Tobias Teichert: Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15261.
Taylor J Abel: Department of Neurological Surgery, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213.
Bharath Chandrasekaran: Department of Communication Sciences and Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 b.chandra@pitt.edu.
Time-varying pitch is a vital cue for human speech perception. Neural processing of time-varying pitch has been extensively assayed using scalp-recorded frequency-following responses (FFRs), an electrophysiological signal thought to reflect integrated phase-locked neural ensemble activity from subcortical auditory areas. Emerging evidence increasingly points to a putative contribution of auditory cortical ensembles to the scalp-recorded FFRs. However, the properties of cortical FFRs and precise characterization of laminar sources are still unclear. Here we used direct human intracortical recordings as well as extracranial and intracranial recordings from macaques and guinea pigs to characterize the properties of cortical sources of FFRs to time-varying pitch patterns. We found robust FFRs in the auditory cortex across all species. We leveraged representational similarity analysis as a translational bridge to characterize similarities between the human and animal models. Laminar recordings in animal models showed FFRs emerging primarily from the thalamorecipient layers of the auditory cortex. FFRs arising from these cortical sources significantly contributed to the scalp-recorded FFRs via volume conduction. Our research paves the way for a wide array of studies to investigate the role of cortical FFRs in auditory perception and plasticity.
