Cognitive processing in literate and illiterate subjects: A review of somerecent behavioral and functional neuroimaging data

The study of illiterate subjects, which for specific socio-cultural reasons did not have the opportunity to acquire basic reading and writing skills, represents one approach to study the interaction between neurobiological an d cultural factors in cognitive development and the functional organization of the human brain. In addition the naturally occurring illiteracy may ser ve as a model for studying the influence of alphabetic orthography on audit ory-verbal language. In this paper we have reviewed some recent behavioral and functional neuroimaging data indicating that learning an alphabetic wri tten language modulates the auditory-verbal language system in a non-trivia l way and provided support for the hypothesis that the functional architect ure of the brain is modulated by literacy. We have also indicated that the effects of literacy and formal schooling is not limited to language related skills but appears to affect also other cognitive domains. In particular, we indicate that Formal schooling influences 2D but not 3D visual naming sk ills. We have also pointed to the importance of using ecologically relevant tasks when comparing literate and illiterate subjects. We also demonstrate the applicability of a network approach in elucidating differences in the functional organization of the brain between groups. The strength of such a n approach is the ability to study patterns of interactions between functio nally specialized brain regions and the possibility to compare such pattern s of brain interactions between groups or functional states. This complemen ts the more commonly used activation approach to functional neuroimaging da ta, which characterize functionally specialized regions, and provides impor tant data characterizing the functional interactions between these regions.