Thesis defense Cathelijne Tesink (Donders Series 114)

7 February 2013

Promotors: Prof.dr.  P. Hagoort, Prof.dr. J Buitelaar

Neurobiological insights into language comprehension in autism: context matters

Impairments in language and communication are among the defining characteristics of autism. In high-functioning individuals with autism, language difficulties are most prominent when language comprehension requires the use of context and the integration of different sources of information. However, it is unclear at what level of language processing and for which types of context these difficulties arise. We therefore used functional MRI to investigate the neural correlates of different types of context information during auditory sentence comprehension in adults with high-functioning autism or Asperger’s disorder compared to control participants. Context type was manipulated by using sentences in which expectations about a speaker based on the voice did or did not match sentence content, as well as sentences with semantic or world knowledge anomalies. Differences between the groups were (mainly) located in language-related regions in left and right inferior frontal cortex, but varied across context types. While differences between the autism and control group were present for speaker inference sentences and sentences with world knowledge anomalies, no between-group effects were found for the semantic anomalies. From these results it follows that the nature of contextual information that needs to be taken into account is an important factor in explaining differences in language comprehension in autism. In addition, difficulties with cognitive flexibility and exception handling as observed in individuals with autism will affect language processing.