An adult with autism and a mild intellectual disability participated in a 0-s delayed matching-to-sample task. In each trial, two sample stimuli were presented together until the participant completed an observing-response requirement consisting of 1 or 10 mouse clicks in the baseline and experimental phases, respectively. One of the two sample stimuli then appeared randomly as a comparison stimulus (S+), along with two other comparison stimuli (S-). Higher levels of correct responding occurred under the larger observing-response requirement, and the proportion of errors related to one of the two sample stimuli decreased. Thus, stimulus overselectivity was reduced without requiring differential observing responses.
Keywords: autism; conditional discrimination; delayed matching to sample; observing response; restricted stimulus control.