Receptive Vocabulary Knowledge in Low-Functioning Autism as Assessed by Eye Movements, Pupillary Dilation, and Event-Related Potentials.

摘要

We have been testing the hypothesis that relatively implicit measures of cognitive processing (eye movements, pupillary dilation monitoring, and the N400 component of event-related potentials) will prove sensitive to receptive vocabulary knowledge, even in the absence of more traditional behavioral responses. We have sought to first demonstrate the use of these measures in three populations in whom behavioral responses are expected to be reliable: normal adults, normally developing children, and higher-functioning individuals with autism. In all three groups, the implicit measures differentiated known from unknown words: eye movements were faster to a named picture for known words; pupillary dilation from baseline was greater in the unknown condition; and an N400 congruency effect was observed for known (but not unknown) words. Our results also suggest that these measures similarly differentiate known from unknown words in lower-functioning individuals with autism, even in the absence of a behavioral response. These results suggest that these measures may be used as valid measures of comprehension, even in nonverbal, non-responding individuals. We have also begun exploring whether these same measures can be used to track learning in lower-functioning individuals with autism that might accompany exposure to new words in a training paradigm.