Retinotopic Organization of Human Visual Cortex: Departures from the Classical Model

Abstract

Retinotopic mapping strategies similar to those used for invasive electrophysiological studies to identify multiple visual areas in monkeys have been adapted for noninvasive studies in humans, using magnetic recordings of brain activity in conjunction with anatomical magnetic resonance imaging. The retinotopic organization of the primary visual area (V1) in the left hemisphere of human subjects was examined by presenting a small patterned stimuli near the vertical and horizontal meridians in the lower right visual field. In contrast with the classical model of V1 retinotopy, our results suggest that the representation of the horizontal meridian does not necessarily correspond in a one-to-one manner with the base of the calcarine fissure and that some lower field stimuli can activate regions in the lower bank of the fissure. The results also indicate significant individual variability in the details of how V1 maps around the calcarine fissure.

Automatic volumetric segmentation of human visual retinotopic cortex

“…This is not surprising since various studies have described variations in functional and anatomical patterns in striate and extrastriate cortex (Aine et al, 1996;Amunts et al, 2000;Dumoulin et al, 2000;Gilissen et al, 1995;Gilissen and Zilles, 1996;Hasnain et al, 1998;Rademacher et al,1993;Roland et al,1997;Steinmetz et al, 1990;Steinmetz and Seitz, 1991;Stensaas et al, 1974;Watson et al, 1993) The variability found here can mainly be attributed to variations in gross anatomy and variations in the relationship between gross anatomy and functional areas, rather than methodological differences.…”

Multi-Source Localization in MEG Using Simulated Annealing: Model Order Determination and Parameter Accuracy

“…Best-fitting source parameters were either accurate estimates of the actual source parameters or represented physiologically plausible solutions which were similar to those obtained previously using other methods [7]. While x2 required a systematic increase in model order as demonstrated earlier [I], the use of a modified cost function allowed for more efficient model order determination white preserving the accuracy of parameter estimation.…”

Retinotopic mapping of visual event-related potentials

“…This is in agreement with Clark and colleagues (1995), who found that the reversal point was on average 15°-20° below the horizontal meridian. Subsequent studies have replicated this finding (Aine et al, 1996;Kelly et al, 2013b;Zhang and Hood, 2004) suggesting that the optimal locations for boosting the C1 inversion effect are not symmetrical (around 25° above and 45° below the horizontal meridian) (Di Russo et al, 2002.…”