アイテム詳細

要旨

Previous research shows that during speech production a forward model is applied which predicts incoming sensations of the actual auditory input (e.g. Ford et al., 2007). However, it is neither fully understood to what extent the forward model can tolerate unexpected changes in the auditory input, nor which brain structures are involved in generating forward predictions during speech. In former experiments self-initiated sounds elicited a suppressed N1-ERP component compared to the N1 to externally produced sounds (e.g. Schafer & Marcus, 1973). It is assumed that the suppression effect is based on generating auditory forward predictions. Furthermore, patient literature proposes that these auditory forward predictions are generated in the cerebellum (Knolle et al., 2012). Processing externally produced sounds, however, seems to be modulated by attentional processing driven by the basal ganglia (BG; Knolle et al., in preparation). We are presently testing 16 healthy participants in a paradigm comparing self- and externally produced speech sounds (vowels /a/, /o/). Both conditions contain 25% deviants (a different vowel). This allows comparing the N1 elicited by self-initiated and externally produced vowels, and deviants. Furthermore, we study attention-based processes (P2-P3) and their involvement in detecting vowel quality changes. In the following we will test patients with cerebellar and BG lesions to examine the involvement of these two subcortical structures in processing of self and externally produced vowels and deviants. In conclusion, the study investigates the role of subcortical structures in complex processes such as the generation of auditory forward predictions, and attentional processing of speech sounds.