Parametrically dissociating speech and nonspeech perception in the brain using fMRI.
Candidate brain regions constituting a neural network for preattentive phonetic perception were identified with fMRI and multivariate multiple regression of imaging data. Stimuli contrasted along speech/nonspeech, acoustic, or phonetic complexity (three levels each) and natural/synthetic dimensions. Seven distributed brain regions' activity correlated with speech and speech complexity dimensions, including five left-sided foci [posterior superior temporal gyrus (STG), angular gyrus, ventral occipitotemporal cortex, inferior/posterior supramarginal gyrus, and middle frontal gyrus (MFG)] and two right-sided foci (posterior STG and anterior insula). Only the left MFG discriminated natural and synthetic speech. The data also supported a parallel rather than serial model of auditory speech and nonspeech perception.
Benson
R R
RR
Department of Neurology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030-2017, USA. benson@nso.uchc.edu
Whalen
D H
DH
Richardson
M
M
Swainson
B
B
Clark
V P
VP
Lai
S
S
Liberman
A M
AM
D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology; D010700:Phonetics; D013067:Speech Perception / Q000502:physiology*