Similarities and differences between acquired and congenital pathologies of the Corpus callosum

There has been an increasing interest on the contribution of the corpus callosum (CC) to the development of cognitive functions and the concurrent hemispheric specialisation . Among the others, communicative abilities are investigated in relation to acquired damage to the corpus callosum (e.g. callosotomy), and to its congenital absence (ACC). Congenital pathologies of the CC do not show the adult’s split brain damages, nevertheless impairments in communication abilities are increasingly reported , while brain functions are described mainly as normally lateralised. Interestingly and differently from other congenital brain malformations or injuries, such communication impairments take developmental time to show up and to reach clinical salience. Indeed, children with ACC perform less well than controls in several linguistic tasks until they are 10-11 year-olds, but differences do not reach statistical significance. Only afterward, differences become clinically salient, with special regard to pragmatic abilities, which require inter-hemispheric integration. It looks like if persistently sub-optimal performances in diverse skills are likely to bring to evident deficits in the complex abilities that are based on those skills. Such a developmental profile is discussed on the background of the Dennis’ and neuroconstructivist theories on brain plasticity