Performance by Older Adults on Identity and Arbitrary Matching-to-Sample Tasks

Abstract

Conditional discrimination procedures have been widely used in the study of complex human behavior such as language and remembering. Examples of these procedures include identity and arbitrary matching-to-sample (MTS) tasks. Although identity matching is described as a prerequisite to arbitrary matching, it has been suggested that beginning with identity MTS tasks may interfere with responding on subsequent arbitrary MTS, as the participant continues to look for similarities rather than responding in accordance with the experimenter-defined contingencies. The purpose of the present experiment was twofold: (1) to study whether exposure on identity MTS would influence arbitrary MTS performance and (2) to determine whether using 0-s delay would provide different results than simultaneous matching in healthy older adults. Thirty-two participants (ages 70–86 years) were divided randomly into four experimental conditions: (a) identity-arbitrary simultaneous MTS; (b) arbitrary-identity simultaneous MTS; (c) identity-arbitrary 0-s DMTS; and (d) arbitrary-identity 0-s DMTS. The results showed that exposure to identity MTS did not hinder responding on subsequent arbitrary MTS. On the contrary, the arbitrary-identity MTS with simultaneous presentation of the stimuli resulted in the highest number of training trials to criterion during training and the highest number of withdrawals from the experiment, whereas identity MTS before arbitrary MTS led to results similar to those when 0-s delay was used. These results are important for future application of conditional discrimination procedures with older adults.