, 2003; Bedny et al., 2011; see reviews in Frasnelli check details et al., 2011; Merabet and Pascual-Leone, 2010; Striem-Amit et al., 2011). Here we show that when relevant
stimuli and tasks are introduced, the ventral visual cortex displays its normal category-specific function, even with stimulation from an unusual sensory modality. Our finding of preserved functional category selectivity for letters in the VWFA is in line with previous results showing preserved task selectivity in the blind (Reich et al., 2012) for general shape recognition in the LOC, for motion detection in area MT, for location identification in the MOG, and even for the general segregation between the ventral and dorsal visual processing streams (Striem-Amit et al., 2012a; for relevant findings in deafness, see Lomber et al., 2010). This suggests that at least some regions may, despite selleck chemicals their bottom-up deafferentation, be sufficiently driven by other innately determined constraints (Mahon and Caramazza, 2011) to develop typical functional selectivity. It remains to be tested whether such task-selective and sensory-modality independence (Reich et al., 2012) characterizes the entire cortex or if it is limited to only a subset of higher-order associative areas.
The present results may have clinical relevance for the rehabilitation of the visually impaired and have theoretical implications as regards the concept of critical/sensitive periods. Until recently, it was thought that the visual cortex of congenitally and early blind individuals
would not be able to properly process vision if visual crotamiton input were restored medically in adulthood. This claim was supported by early studies of a critical period for developing normal sight in animals (Wiesel and Hubel, 1963) and humans (Lewis and Maurer, 2005). It was also supported by the poor functional outcomes observed after rare cases of sight restoration in humans, especially in ventral stream tasks (Ackroyd et al., 1974; Fine et al., 2003; Ostrovsky et al., 2009). In the congenitally blind, this may be especially true due to the aforementioned task switching (e.g., for language and memory) that may possibly disturb the visual cortex’s original functions and interfere with attempts to restore vision (Striem-Amit et al., 2011). Therefore, even if visual information later becomes available to their brain (via devices such as retinal prostheses), it may be less efficient at analyzing and interpreting this information and may require more elaborate explicit training to develop fully functional vision. Some support for the effectiveness of adult training in overcoming developmental visual impairments comes from recent studies of amblyopia, in which deficits were considered permanent unless treated by the age of 7.