title: Norm-based coding of voice identity in human auditory cortex.
abstract: Listeners exploit small interindividual variations around a generic acoustical structure to discriminate and identify individuals from their voice-a key requirement for social interactions. The human brain contains temporal voice areas (TVA) involved in an acoustic-based representation of voice identity, but the underlying coding mechanisms remain unknown. Indirect evidence suggests that identity representation in these areas could rely on a norm-based coding mechanism. Here, we show by using fMRI that voice identity is coded in the TVA as a function of acoustical distance to two internal voice prototypes (one male, one female)-approximated here by averaging a large number of same-gender voices by using morphing. Voices more distant from their prototype are perceived as more distinctive and elicit greater neuronal activity in voice-sensitive cortex than closer voices-a phenomenon not merely explained by neuronal adaptation. Moreover, explicit manipulations of distance-to-mean by morphing voices toward (or away from) their prototype elicit reduced (or enhanced) neuronal activity. These results indicate that voice-sensitive cortex integrates relevant acoustical features into a complex representation referenced to idealized male and female voice prototypes. More generally, they shed light on remarkable similarities in cerebral representations of facial and vocal identity.
authors.affiliation: Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, Scotland. mlatinus@gmail.com
authors.forename: Marianne
authors.initials: M
authors.lastname: Latinus
authors.forename: Phil
authors.initials: P
authors.lastname: McAleer
authors.forename: Patricia E G
authors.initials: PE
authors.lastname: Bestelmeyer
authors.forename: Pascal
authors.initials: P
authors.lastname: Belin
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D046709:Pattern Recognition, Physiological; D013061:Speech Acoustics; D014831:Voice / Q000502:physiology