Children with autism spectrum disorders vary considerably in their language abilities, but even verbally proficient children have difficulty with two aspects of language: pragmatic inference, which uses context to understand the meaning of a sentence, and prosodic comprehension, which uses speakers' tone to understand the feelings, attitude and information they wish to convey. Although children with autism have difficulty with both skills, the extent of these difficulties and their causes are poorly understood.
To examine these issues, Jesse Snedeker of Harvard University and her colleagues are examining in real time the processes that occur as children understand language. Rather than ask children to point at pictures or answer questions — standard approaches that reveal what the children understand, but not how they arrive at this understanding — Snedeker and colleagues use a computer to track children's eye movements as they listen to sentences while viewing a corresponding scene.
The timing and direction of the children's gaze provide clues to how they process information in a sentence. For example, if children are asked to pick the 'tiger' from a set of animals, they will generally shift their gaze to the tiger even before that word ends.
Snedeker's team has found that eye movements can also be used to measure complex grammatical processes. In typically developing children, these processes are quickly influenced by the prosody of the sentence and the pragmatic context in which it is used.
The researchers plan to track eye movements to determine whether highly verbal children with autism can also use prosody and pragmatics to guide language comprehension — for example, whether they understand that pronouns typically refer to recently mentioned people, or whether they can infer that an emphasized word is likely to refer to something new or unexpected.
The project may shed light on the extent to which children with autism have problems with prosody and pragmatics, and how these difficulties limit their ability to understand language in context.