[PS-1.15] Does language experience modulate the generation of predictions in primary auditory cortex?

Morucci, P. , Martin, C. . & Molinaro, N. .

Basque Center on Cognition Brain and Language

According to hierarchical predictive coding models of auditory cortex, cortical regions sensitive to specific aspects of a stimulus (e.g. auditory duration) use memories of recent past to build internal models of the environment and generate anticipations of future events. In this study, we investigate whether life-long exposure to linguistic regularities interacts with lower-level expectations processes in the construction of auditory sensory representations. To do so, we compare EEG and MEG data from highly proficient bilinguals of Basque (Basque L1; Spanish L2) and Spanish (Spanish L1; Basque L2), two languages that crucially differ in their syntactic/prosodic structure: Spanish is a functor-initial language, in which short sounds (i.e. function words) usually precede long sounds (i.e. content words), whereas Basque is a functor-final language in which long sounds (i.e. content words) usually precede short sounds (i.e. function words). Subjects are presented with 30seconds-long sequences of two tones alternating in duration at fixed intervals. In each sequence, two to six tone omissions occur quasirandomly. EEG and MEG responses to omitted sounds are recorded. A hierarchical predictive coding model predicts that the omission of a long tone should elicit a larger omission response in L1 Spanish speakers compared to the Basque dominant population, as it represents the violation of two predictions in the Spanish, but not in the Basque: a local prediction based on the statistical regularities of previous stimuli, and language-induced prediction based on the statistical regularities of Spanish syntax. The opposite pattern is expected in the Basque population. Preliminary results will be presented and discussed.