Objectives: The aim of the present study was to map the inclination of people with and without ASD to monitor global aspects of language, and compare monitoring processes in a simple, single level task to those in a more complex, dual level task.
Methods: Participants were 14 high-functioning adults with ASD and 14 controls. The clinical and control group were matched on gender, age, intelligence and working memory. A dual-task experiment was developed to examine monitoring of global language aspects in a simple and a more complex condition. Participants were instructed to focus on global, syntactic errors in I) a single level condition with attentional focus only on syntactic errors, and II) a dual level condition with attentional focus both on syntactic errors and on orthographic errors. During the experiment ERPs were recorded. We compared the P600 effect to syntactic errors relative to correct sentences in participants with ASD as well as control participants, in the single and the dual level condition.
Results: For people without ASD, a monitoring response (as tapped by the P600 effect) to global errors was found only in the dual level condition. People with ASD, however, showed a monitoring response to global errors in both the single level and the dual level condition.
Conclusions: These ERP findings suggest that people with ASD monitor global aspects of language already under simple circumstances, whereas people without ASD only do so under more complex circumstances. Possibly, for individuals with ASD, global language perception costs more attention, resulting in impaired language comprehension in more complex situations. This would indicate that language problems in ASD might not result from a linguistic dysfunction as such, but from an increased need for executive resources to achieve optimal language comprehension.