Preserved visual categorical coding in the ventral occipito-temporal cortex despite transient early blindness and permanent alteration in the functional response of early visual regions

It has been suggested that a transient period of postnatal visual deprivation affect the development of object categorization in the visual system. Here we overturn this assumption by demonstrating typical categorical coding in the ventral occipito-temporal cortex (VOTC) despite early visual deprivation and pervasive alteration in the functional response in the early visual cortex (EVC). We used fMRI to characterize the brain response to five visual categories (faces, bodies, objects, buildings and words) in a group of cataract-reversal individuals who experienced a short and transient period of blindness early in life, and in a group of control participants with typical visual development. Using a combination of uni- and multi-variate analyses, we show that the encoding of low-level visual properties of our stimuli is impaired in EVC in cataract-reversal participants, while there is a preservation of the categorical response in the VOTC. When altering the visual properties of our stimuli to mimic in controls the deficit of EVC response of the cataract, we observe a cascading alteration of the categorical coding from EVC to VOTC that is not observed in the cataract-reversal group. Our results suggest that we do not need visual experience early in life to develop the typical visual categorical organization in VOTC, even in the presence of impaired low-level visual processing in EVC. These results challenge the classical view of a feedforward development of categorical selectivity in VOTC according to which the categorical organization of high-level regions depends on low-level visual protomaps.