TY - CONF A1 - Greenlee, Mark W. A1 - Anstis, Stuart A1 - Rosengarth, Katharina A1 - Goldhacker, Markus A1 - Brandl-Rühle, Sabine A1 - Plank, Tina T1 - Neural correlates of perceptual filling-in: fMRI evidence in the foveal projection zone of patients with central scotoma T2 - Journal of Vision / Vision Sciences Society Annual Meeting Abstract N2 - Patients with juvenile retinal dystrophy often report that they are unaware of their central scotoma, suggesting the presence of perceptual filling-in. We used functional Magnetic Resonance Imaging (fMRI) to determine possible neural correlates of perceptual filling-in in patients with retinal distrophy and clinically established central scotoma in both eyes. The data of 5 patients (Stargardt disease, cone-rod dystrophy; mean age 45 yrs; scotoma diameter 10-20°) and of 5 normally sighted controls were analyzed. Fixation behaviour and perimetry were measured with a Nidek microperimeter. Magnetic resonance imaging was performed using a Siemens 3T Allegra scanner. We stimulated the central visual field (30 deg) with a vertically oriented, low spatial frequency (1 c/deg) high-contrast sinewave grating that was either a) continuous, or b) was interrupted by a central grey disk. The disk was either slightly larger than the scotoma (detectable on 75% of trials) or slightly smaller (detectable on 25% of trials). To control for attention, an eccentric fixation task was performed during scanning. Data were analyzed using SPM8 (GLM with ROI analysis to obtain percent signal change for foveal projection zone). Results: for all patients, the BOLD signal in the foveal projection area was significantly higher for the small disk (i.e., condition leading to complete filling-in) than for the large disk (i.e., no filling-in). This effect was absent in the control subjects. Our findings support the existence of an active neural process that leads to filling-in in patients with central visual field scotomata. Y1 - 2012 UR - https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/5311 SN - 1534-7362 VL - 12 IS - 9 PB - ARVO ER -