Perception of complex sounds: abnormal pattern of cortical activation in autism.
OBJECTIVE
Bilateral temporal hypoperfusion at rest was recently described in autism. In normal adults, these regions are activated by listening to speech-like sounds. To investigate auditory cortical processing in autism, the authors performed a positron emission tomography activation study.


METHODS
Regional cerebral blood flow was measured in five autistic adults and eight comparison subjects during rest and while listening to speech-like sounds.


RESULTS
Similar to the comparison subjects, autistic patients showed a bilateral activation of the superior temporal gyrus. However, an abnormal pattern of hemispheric activation was observed in the autistic group. The volume of activation was larger on the right side in the autistic patients, whereas the reverse pattern was found in the comparison group. The direct comparison between the two groups showed that the right middle frontal gyrus exhibited significantly greater activation in the autistic group. Conversely, the left temporal areas exhibited less activation in autistic patients.


CONCLUSIONS
These findings suggest that abnormal auditory cortical processing is implicated in the language impairments and the inadequate response to sounds typically seen in autism.
Boddaert
Nathalie
N
ERM 0205, Division of Life Sciences, Department of Medical Research, INSERM-CEA-Service Hospitalier Frédéric Joliot, 4 place du Général Leclerc, 91406 Orsay, France.
Belin
Pascal
P
Chabane
Nadia
N
Poline
Jean-Baptiste
JB
Barthélémy
Catherine
C
Mouren-Simeoni
Marie-Christine
MC
Brunelle
Francis
F
Samson
Yves
Y
Zilbovicius
Mônica
M
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology*; D001321:Autistic Disorder / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D010104:Oxygen Radioisotopes; D012039:Regional Blood Flow / Q000502:physiology; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D014055:Tomography, Emission-Computed; D014867:Water
D010104:Oxygen Radioisotopes; D014867:Water