The continuous performance test : exploratory studies comparing schedules of reinforcement : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Psychology with an endorsement in Clinical Psychology at Massey University

Abstract

The first study was designed to demonstrate that Continuous Performance Test responding was subject to reinforcement effects. A version of the CPT which requires detection of a target stimulus which had been preceded by another, and which required subjects to respond on one key to target stimuli and on another to all other stimuli was used. Responding during baseline was compared with conditions where correct responses to target stimuli were reinforced and all correct responses were reinforced for four intellectually handicapped subjects using an ABCBA design. The results demonstrated a rise in impulsivity with reinforcement delivery. The overall results although weak showed that reinforcement did alter behaviour on the CPT and reinforcing correct responding on both keys was better than just reinforcing correct responding on one key, in terms of accuracy, time on-task and efficiency. Experiment II used a version of the CPT which requires detection of a target stimulus, and which required subjects to respond on one key to target stimulus and on another to all other stimuli. To reduce anticipatory responding impulsivity was redefined by dramatically shortening the period of time available for impulsive responses to occur. Two intermittent schedules were compared to explore the capabilities of the CPT as a research tool to compare between schedules of reinforcement. An alternating treatments design, with baseline being one of the treatment conditions, was used with four intellectually handicapped subjects. The results, though weak, were able to show a difference in performance under the schedules. As predicted, impulsivity was low. There were indications for the

potential of developing the CPT as a research tool. Suggestions for further research were offered.