The last two lectures were devoted to applying these general principles to two specific areas of primary education : learning to read and to do arithmetic. In both these areas, a great deal of research supports the hypothesis of neural recycling (the importance of constraints imposed by pre-existing neural circuits), the importance of brain plasticity, and the role of automation.
In the case of reading, it is a circuit involving the visual cortex of the left hemisphere, within the lateral occipitotemporal sulcus, that is modified during learning. It develops a representation of letters and their sequence to form written words. This visual region plays a pivotal role : its projections to different sectors of the temporal lobe are modified to represent, on the one hand, correspondences between graphemes and phonemes (deciphering or phonological reading pathway) and, on the other, the direct passage from the chain of letters to the meaning of words (lexical-semantic pathway). A comparison of literate and non-literate individuals shows that occipito-temporal circuits in the left hemisphere are profoundly altered by learning to read: visual cortex is modified, including in its earliest stages; face representation is displaced ; mirror invariance is slightly reduced ; and auditory areas in the planum temporale also see their activity increase. Moreover, during the early stages of learning, attentional networks in the parietal and frontal lobes are strongly activated, but this contribution diminishes as reading becomes more automatic, while temporal activation increases.
