title: Individual Differences in the Frequency-Following Response: Relation to Pitch Perception.
abstract: The scalp-recorded frequency-following response (FFR) is a measure of the auditory nervous system's representation of periodic sound, and may serve as a marker of training-related enhancements, behavioural deficits, and clinical conditions. However, FFRs of healthy normal subjects show considerable variability that remains unexplained. We investigated whether the FFR representation of the frequency content of a complex tone is related to the perception of the pitch of the fundamental frequency. The strength of the fundamental frequency in the FFR of 39 people with normal hearing was assessed when they listened to complex tones that either included or lacked energy at the fundamental frequency. We found that the strength of the fundamental representation of the missing fundamental tone complex correlated significantly with people's general tendency to perceive the pitch of the tone as either matching the frequency of the spectral components that were present, or that of the missing fundamental. Although at a group level the fundamental representation in the FFR did not appear to be affected by the presence or absence of energy at the same frequency in the stimulus, the two conditions were statistically distinguishable for some subjects individually, indicating that the neural representation is not linearly dependent on the stimulus content. In a second experiment using a within-subjects paradigm, we showed that subjects can learn to reversibly select between either fundamental or spectral perception, and that this is accompanied both by changes to the fundamental representation in the FFR and to cortical-based gamma activity. These results suggest that both fundamental and spectral representations coexist, and are available for later auditory processing stages, the requirements of which may also influence their relative strength and thus modulate FFR variability. The data also highlight voluntary mode perception as a new paradigm with which to study top-down vs bottom-up mechanisms that support the emerging view of the FFR as the outcome of integrated processing in the entire auditory system.
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Canada.|Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada.|Centre for Research on Brain, Language and Music (CRBLM), Montreal, Canada.
authors.forename: Emily B J
authors.initials: EB
authors.lastname: Coffey
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Canada.
authors.forename: Emilia M G
authors.initials: EM
authors.lastname: Colagrosso
authors.affiliation: Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada.|Centre for Research on Brain, Language and Music (CRBLM), Montreal, Canada.|Department of Psychology, University of Montreal, Montreal, Canada.|Department of Otolaryngology Head & Neck Surgery, McGill University, Montreal, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Lehmann
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Canada.|Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada.|Centre for Research on Brain, Language and Music (CRBLM), Montreal, Canada.|Department of Psychology, University of Montreal, Montreal, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Schönwiesner
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Canada.|Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Canada.|Centre for Research on Brain, Language and Music (CRBLM), Montreal, Canada.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Zatorre
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception; D004566:Electrodes; D004569:Electroencephalography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D008416:Mastoid / Q000502:physiology; D008875:Middle Aged; D009420:Nervous System; D010898:Pitch Perception; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D055815:Young Adult