Brain representation of phonological processing in Italian: individual variability and behavioural correlates

Abstract

Neuroimaging literature on phonological processing during reading lacks of studies taking into account orthografic differences across languages and behavioural variability across subjects. The present study aimed at investigating brain representation of phonological processing in reading Italian, a language with regular orthography, with particular regard to inter-individual variability and brain-behavioural correlates. Ten Italian adults performed a rhyme generation and a rhyme judgement task during fMRI acquisition and were tested with behavioural measures of phonological processing. Results for both tasks show activations of the left Inferior Frontal Gyrus and Dorsolateral Prefrontal Cortex, likely underlying output sub-lexical strategies, for all or most of the subjects, while a minority of subjects activated the Superior Temporal Sulcus and the Temporo-parietal-occipital Junction. These results suggest that phonological processing of written Italian is based on the prevalent use of frontal structures. However, it is of interest that the activation of the Superior Temporal Sulcus, involved in phonological input and lexical access, was associated to better behavioural performances in tasks of phonological processing. Our findings may contribute to understand neural correlates of phonological processing of languages with regular orthography.