Date of Award

Winter 1981

Project Type


Program or Major


Degree Name

Doctor of Philosophy


Selective stimulus control refers to the functional relationships that are developed between the various stimulus elements of a discriminative stimulus and the subject's response. A multi-element conditional discrimination problem is an effective means of studying these relationships. In the first experiment, preschool and adult subjects were presented with a series of conditional discrimination problems. They were required to respond differentially to two multi-element stimulus cards by touching one of two response circles, one red and one blue. Each problem set contained either two, four, six, or eight elements per stimulus card. The discrimination was established using an errorless training procedure and stimulus control by the individual elements was assessed by a sorting task following acquisition of each discrimination problem. During the sorting task, all elements that comprised the multi-element stimulus cards were individually presented in random order. Subjects were asked to place all elements under the response circle that they thought the element belonged to. Following stimulus control assessment of the last discrimination problem, subjects were given two additional training and stimulus control sessions with that problem to assess the effect of overtraining. Both the adults and preschool subjects showed control by proportionately fewer elements as the number of elements in successive multi-element discriminative stimuli increased. The number of elements demonstrating control in each problem set for both groups was similar. The two groups differed, however, when given overtraining on the last problem set. The preschool subjects showed no increase in the number of elements meeting stimulus control criteria when given additional training. The adults did show increased control, eventually correctly sorting all stimulus elements.

In the second experiment, preschool subjects were given multi-element conditional discrimination problems having either elements the children could label, elements the children could not reliably label, or a combination of both. The same discrimination training and stimulus control assessment procedures used in the first experiment were in the second. The results show that more elements in the labeled condition were correctly sorted than either the non-labeled or combination conditions.

The results of this study document the functional characteristics of three relevant factors in the development of selective stimulus control. In addition, the data extend the results obtained by Lovass, et al., Ray, and Hugunin and Touchette.