Neural correlates of the integration of gestures and speech in autistic spectrum disorders

People with ASD have difficulty with understanding several aspects of language
and more in particular with pragmatic language processing. In daily life,
pragmatic language plays an improtant role in communication. For example, when
someone talks to us, we not only hear speech but also see the speaker's hand,
mouth and body movements. In conversational settings, the brain therefore
continuously integrates language and information coming from other sources to
improve the listener's understanding of a speaker's message. The integration of
gesture and speech can be seen as a pragmatic aspect of language, i.e. the
integration of language in context. It is the integration of information in a
context that people with ASD have problems with. The uncovering of the
neurofunctional organization of language in ASD and the dissection of the
neural correlates of the various language components (pragmatic versus semantic
aspects of language) would contribute to a better understanding of the neural
base of ASD.

The primary objective of this study is to identify the neural correlates of
language functions and, in particular, abnormal pragmatic communication in
autistic spectrum disorders. The secondary objective of this study is to relate
resting state activity in the brain of people with ASD to neural correlates of
pragmatic language functioning to and see whether pragmatic language functions
are influenced by resting state activity in the brain.

To investigate pragmatic language, or more in detail, how integration of
gestures and speech takes place in the autistic brain, we use fMRI and compare
activation patterns of people with ASD and healthy controls. While lying in the
MRI scanner, participants listen to sentences presented by headphones and, at
the same time, they see short movies on a screen which contain gestures that do
or do not match the spoken content of the sentences. A comparison will be made
of fMRI images of both groups and based on this comparison of brain
activations, conclusions can be drawn about neural correlates of the
integration of gestures and speech and therefore about pragmatic language in
ASD. Next to listening to sentences and watching movies, subjects are asked to
lie still in de MRI scanner for ten minutes. In this period fMRI images of the
brain in resting state can be collected. This provides us with the oppurtunity
to relate resting state activity to activation related to pragmatic language
aspects and this will improve the interpretation of activation patterns during
the pragmatic language task.

This fMRI study has already been done in healthy subjects by another researcher
at the F.C. Donders centre and the coordinating investigator already has
performed similar fMRI reasearch in people with ASD. Based on this experience
it is estimated that the burden perceived by the subjects will be minimal.
Participants will undergo a one hour scanning session in the MRI scanner. This
session is divided in two sessions of 30 minutes separated by a 15-minute
break. The F.C. Donders Centre has a lot of experience with the research we are
proposing in this protocol and there are no special risks associated with this
kind of research.