Attending Behavior in Matching-to-Sample Procedures

An Investigation of Variables Affecting Restrictive Stimulus Control and Eye Movements

Abstract

This dissertation consists of three published studies that have an overarching objective to evaluate various environmental variables' effects on restrictive stimulus control and observing responses, which are behaviors often characterized as attention. Studies 1 and 2 investigated restricted stimulus control in matching-to-sample (MTS) procedures with compound stimuli. In both studies, participants established responses in the presence of compound stimuli of color and shape. The conditional discrimination procedures were followed with a test where the two elements of the compound stimuli were separated and tested individually to examine which part of the stimuli participants attended to or exerted control of the participants’ responses. In Study 1, restrictive stimulus control was investigated in two experiments in an identity MTS procedure. Restricted stimulus control was demonstrated in Experiment 1. In Experiment 2, two groups of participants were compared regarding different lengths of delay (0 and 3s.) between the sample and comparison stimuli presentation in training. Results showed more participants showing restricted stimulus control when trained with a 0s delay. In Study 2, an arbitrary MTS procedure was arranged with compound and abstract stimuli trained as a stimulus class. A one-to-many and many-to-one training structure was used to teach twelve conditional discriminations to each of the two groups of participants. Restricted stimulus control was tested by separating the compound stimuli and testing the elements individually. Individual elements were also tested as part of a stimulus equivalence class. Participants who showed restricted stimulus control responded correctly only to color stimuli when trained with a many-to-one training structure. Whereas those trained with one-to-many, had errors to both elements of the compound stimuli. Study 3 analyzed the effect meaningful stimuli have on eye movements in an MTS procedure and a test for stimulus equivalence relations. In this experiment, eye movements were measured using a head-mounted eyetracker, and fixation durations to different stimuli, along with the number of transitions and trials with repeated gaze to the sample stimulus, were measured. Several measures showed that meaningful stimuli affect eye movements by reducing fixation time and the number of transitions between stimuli.