Functional imbalance of visual pathways indicates alternative face processing strategies in autism.
OBJECTIVE
To investigate whether autistic subjects show a different pattern of neural activity than healthy individuals during processing of faces and complex patterns.


METHODS
Blood oxygen level-dependent (BOLD) signal changes accompanying visual processing of faces and complex patterns were analyzed in an autistic group (n = 7; 25.3 [6.9] years) and a control group (n = 7; 27.7 [7.8] years).


RESULTS
Compared with unaffected subjects, autistic subjects demonstrated lower BOLD signals in the fusiform gyrus, most prominently during face processing, and higher signals in the more object-related medial occipital gyrus. Further signal increases in autistic subjects vs controls were found in regions highly important for visual search: the superior parietal lobule and the medial frontal gyrus, where the frontal eye fields are located.


CONCLUSIONS
The cortical activation pattern during face processing indicates deficits in the face-specific regions, with higher activations in regions involved in visual search. These findings reflect different strategies for visual processing, supporting models that propose a predisposition to local rather than global modes of information processing in autism.
Hubl
D
D
Department of Psychiatric Neurophysiology, University Hospital of Clinical Psychiatry, Bern, Switzerland. hubl@puk.unibe.ch
Bölte
S
S
Feineis-Matthews
S
S
Lanfermann
H
H
Federspiel
A
A
Strik
W
W
Poustka
F
F
Dierks
T
T
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001321:Autistic Disorder / Q000175:diagnosis / Q000503:physiopathology*; D001519:Behavior; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping; D004644:Emotions; D005145:Face; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation / Q000379:methods; D014795:Visual Pathways / Q000503:physiopathology*