title: Cerebral correlates of impaired grating perception in individual, psychophysically assessed human amblyopes.
abstract: We investigated neuronal correlates of amblyopic deficits resulting from early onset strabismus or anisometropia by monitoring individual responses in retinotopically mapped cortical visual areas with functional magnetic resonance imaging (fMRI) in eight psychophysically assessed adult amblyopes. In lower visual areas (V1/V2), grating stimuli presented to the normal and the amblyopic eye evoked strong cortical responses, while responses to the amblyopic eye were progressively reduced in higher areas on the central visual pathway (V3a/VP; V4/V8; lateral occipital complex, LOC). Selective reduction for high spatial frequency gratings was especially obvious in LOC. This suggests that transmission of activity from the amblyopic eye is increasingly impaired while it is relayed towards higher processing levels. Elevated responses in parts of areas V1 and V2 to monocular stimulation of the amblyopic eye might be related to the spatial and temporal distortions experienced by some amblyopic subjects.
authors.affiliation: Department of Neurophysiology, MaxPlanck Institute for Brain Research, Deutschordenstrasse 46, 60528 Frankfurt a.M., Germany. Muckli@mpih-frankfurt.mpg.de
authors.forename: Lars
authors.initials: L
authors.lastname: Muckli
authors.forename: Stefan
authors.initials: S
authors.lastname: Kiess
authors.forename: Nathalie
authors.initials: N
authors.lastname: Tonhausen
authors.forename: Wolf
authors.initials: W
authors.lastname: Singer
authors.forename: Rainer
authors.initials: R
authors.lastname: Goebel
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Sireteanu
mesh_terms: D000328:Adult; D000368:Aged; D000550:Amblyopia / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual; D010468:Perceptual Disorders / Q000209:etiology* / Q000503:physiopathology; D010775:Photic Stimulation / Q000379:methods; D011594:Psychometrics; D011601:Psychophysics; D012029:Refraction, Ocular; D013285:Strabismus / Q000503:physiopathology / Q000523:psychology; D014793:Visual Cortex / Q000503:physiopathology*