Factors Determining Where Category-Selective Areas Emerge in Visual Cortex

• Published in: Trends in cognitive sciences 2019-09, Vol.23 (9), p.784-797
• Main Authors: Op de Beeck, Hans P., Pillet, Ineke, Ritchie, J. Brendan
• Format: Article
• Language: English
• Subjects: categorization; cognitive neuroscience; occipitotemporal cortex; vision sciences
• ISSN: 1364-6613; 1879-307X
• DOI: 10.1016/j.tics.2019.06.006

A hallmark of functional localization in the human brain is the presence of areas in visual cortex specialized for representing particular categories such as faces and words. Why do these areas appear where they do during development? Recent findings highlight several general factors to consider when answering this question. Experience-driven category selectivity arises in regions that have: (i) pre-existing selectivity for properties of the stimulus, (ii) are appropriately placed in the computational hierarchy of the visual system, and (iii) exhibit domain-specific patterns of connectivity to nonvisual regions. In other words, cortical location of category selectivity is constrained by what category will be represented, how it will be represented, and why the representation will be used. The human occipitotemporal cortex (OTC) contains functional areas that exhibit strong selectivity for categories such as faces, bodies, hands, word forms, numerals, tools, landmarks, and scenes.Why these areas emerge where they do is poorly understood. On one hand, it has been argued that the emergence of these areas requires visual experience. On the other hand, these areas can be present in blind participants or reflect domain-general processes.Recent findings highlight three factors that constrain the cortical location of these areas: (i) pre-existing selectivity for stimulus properties; (ii) location in the computational hierarchy of the visual system; and (iii) domain-specific connectivity to nonvisual regions.Considering all three factors may resolve the incongruencies and controversies that arise from a narrower focus on a single contributing factor or a particular brain area.