Broca's area and the discrimination of frequency transitions: a functional MRI study.
The left inferior frontal lobe has been traditionally viewed as a "language area," although its involvement in the discrimination of rapid nonverbal frequency changes has been also shown. Using functional MRI, we studied seven healthy adults during discrimination of relatively slow (200 ms) tonal frequency glides. Compared to a control task, in which subjects indiscriminately responded to white noise bursts, tonal discrimination was associated with bilateral superior and middle temporal and medial frontal activations. Inferior frontal activations were bilateral, but stronger on the left. Contrary to previous studies comparing discrimination of slow frequency changes to rest, our results suggest that such discriminations-when compared to an auditory control task-activate the left inferior frontal gyrus. Our findings are consistent with a participation of Broca's area in nonlinguistic processes besides its known roles in semantic, syntactic, and phonological functions.
Müller
R A
RA
Laboratory for the Neuroscience of Autism, Children's Hospital Research Center, La Jolla, California 92037, USA. amueller@ucsd.edu
Kleinhans
N
N
Courchesne
E
E
D000328:Adult; D001039:Aphasia, Broca / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male