Audio-visual speech integration in the superior temporal region is dysfunctional in dyslexia

Faculty/Professorship: Experimental Psychology: Cognition and Emotion  
Author(s): Ye, Zheng; Rüsseler, Jascha  ; Gerth, Ivonne; Münte, Thomas Frank; Szycik, Gregor R.
Title of the Journal: Neuroscience
Publisher Information: Amsterdam [u.a.] : Elsevier Science
Year of publication: 2017
Volume: 356
Pages: 1-10
Language(s): English
DOI: 10.1016/j.neuroscience.2017.05.017
Dyslexia is an impairment of reading and spelling that affects both children and adults even after many years of schooling. Dyslexic readers have deficits in the integration of auditory and visual inputs but the neural mechanisms of the deficits are still unclear. This fMRI study examined the neural processing of auditorily presented German numbers 0-9 and videos of lip movements of a German native speaker voicing numbers 0-9 in unimodal (auditory or visual) and bimodal (always congruent) conditions in dyslexic readers and their matched fluent readers. We confirmed results of previous studies that the superior temporal gyrus/sulcus plays a critical role in audiovisual speech integration: fluent readers showed greater superior temporal activations for combined audiovisual stimuli than auditory-/visual-only stimuli. Importantly, such an enhancement effect was absent in dyslexic readers. Moreover, the auditory network (bilateral superior temporal regions plus medial PFC) was dynamically modulated during audiovisual integration in fluent, but not in dyslexic readers. These results suggest that superior temporal dysfunction may underly poor audiovisual speech integration in readers with dyslexia.
Peer Reviewed: Ja
International Distribution: Ja
Type: Article
Year of publication: 16. January 2018