Background: The study reported here was an examination of the reliability of a method for determining acquiescent responding and the capacity to respond to items using a Likert scale response format by adults with an intellectual disability. Method: Reliability of the outcomes of these procedures was investigated using a test-retest design.…

Stimulus overselectivity occurs when only one of potentially many aspects of the environment controls behavior. Adult participants were trained and tested on a trial-and-error discrimination learning task while engaging in a concurrent load task, and overselectivity emerged. When responding to the overselected stimulus was reduced by reinforcing a…

How strategies affect learning of categories that lack necessary and sufficient attributes is explored. The authors propose that strategy variations induced by instructions affect only the amount of information represented about attributes, not processes operating on representations. An experiment required subjects to classify schematic faces into…

This study examined the discriminability of lexigrams versus printed words with eight adults with severe mental retardation. A match-to-sample teaching paradigm was used. Subjects discriminated lexigrams better than printed letters and were more successful at matching lexigrams to referent objects than matching printed words to referent objects.…

Two experiments explored the nature of perceptual development in 5- and 10-year olds and adults. The primary finding was that preassessed salience significantly influenced 5-year olds' ability to discriminate two objects, while salience did not affect 10-year olds' or adults' response times. Results showed that salience effects in perceptual…