Contralateral Biases in Category-selective Areas Are Stronger in the Left Hemisphere than the Right Hemisphere

摘要

Contralateral bias is a well-known feature of early visual cortex,but how it varies across higher-level, category-selective visual cortexand how much that bias differs between preferred and nonpreferredis unclear. Here, we examined 12 category-selectiveregions across 4 experiments using peripherally presented faces,bodies, houses, and scenes, to measure the difference in contralateralbias between preferred and nonpreferred stimuli. Theresults showed a substantial range of contralateral biases acrossthe category-selective regions, similar to prior studies usingcategory-selective stimuli [Silson, E. H., Groen, I. I., & Baker,C. I. Direct comparison of contralateral bias and face/scene selectivityin human occipitotemporal cortex. Brain Structure andFunction, 227, 1405-1421, 2022; Gomez, J., Natu, V., Jeska, B.,Barnett, M., & Grill-Spector, K. Development differentially sculptsreceptive fields across early and high-level human visual cortex.Nature Communications, 9, 788, 2018; Silson, E. H.,Groen, I. I. A.,Kravitz, D. J., & Baker, C. I. Evaluating the correspondencebetween face-, scene-, and object-selectivity and retinotopic organizationwithin lateral occipitotemporal cortex. Journal of Vision,16, 14, 2016; Kay, K. N., Weiner, K. S., & Grill-Spector, K. Attentionreduces spatial uncertainty in human ventral temporal cortex.Current Biology, 25, 595-600, 2015; Silson, E. H., Chan, A. W.-Y.,Reynolds, R. C., Kravitz, D. J., & Baker, C. I. A retinotopic basis forthe division of high-level scene processing between lateral andventral human occipitotemporal cortex. Journal of Neuroscience,35, 11921-11935, 2015]. These contralateral biases were strongerin the left hemisphere regions than right, an asymmetry that wasunchanged even when participants performed an attentionallydemanding task. Thus, corresponding pairs of category-selectiveregions (e.g., left fusiform face area [lFFA] and right FFA [rFFA])do not appear to be mirror images of each other; instead, theright hemisphere regions engage in greater integration ofinformation from the two hemifields. The rFFA and right fusiformbody area-both located on the right lateral fusiformgyrus-consistently had the weakest contralateral biases. Thatthis asymmetry was most pronounced in the fusiform gyrusmay account for why a unilateral lesion to the rFFA but notthe lFFA can produce prosopagnosia. Together, our findingsdemonstrate that category-selective areas show pronounceddifferences in the extent of their contralateral biases and thata consistent asymmetry in the strength of the contralateralbiases exists between the two hemispheres.