Systematic retinotopic reaching error vectors in unilateral optic ataxia.
The main aim of this study is to determine the reference frame of the pointing errors that characterize patients with unilateral optic ataxia (OA). The reaching errors of seven patients with unilateral OA when pointing on a 2D matrix in peripheral vision were investigated in order to better qualify the reference frame of their deficit. Patients were asked to fixate a central target and then to point at one of 24 visual targets presented in their left or right peripheral visual fields, with their left or right hands. The four left and the three right hemisphere lesion patients with OA exhibited an identical pattern of results. In the contralesional visual field, error vectors were systematically directed toward the fixation point, rather than horizontally toward the side of the lesion. OA results from a deficit in transforming targets' eye-centred coordinates into appropriate motor commands.
Espace et Action, INSERM U864, 16 avenue du Doyen Lépine, Bron, France.
Annabelle
A
Blangero
Hisaaki
H
Ota
Yves
Y
Rossetti
Toshikatsu
T
Fujii
Hiroya
H
Ohtake
Michio
M
Tabuchi
Alain
A
Vighetto
Atsushi
A
Yamadori
Philippe
P
Vindras
Laure
L
Pisella
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001259:Ataxia / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D002545:Brain Ischemia / Q000150:complications / Q000473:pathology; D001931:Brain Mapping; D005123:Eye / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011859:Radiography; D011930:Reaction Time; D013028:Space Perception / Q000502:physiology; D014785:Vision, Ocular; D014794:Visual Fields / Q000502:physiology; D014795:Visual Pathways / Q000473:pathology