“Generalized imitation” on a nonimitative task: Effects of modeling and task history

Two experiments investigated characteristic generalized imitation procedures on a nonimitative successive visual discrimination task. In Experiment I, no discriminative behavior was obtained though a number of procedures designed to enhance discrimination were employed. The introduction of a differential modeling procedure after nine or 10 sessions of nondifferential performance was ineffective in producing differential responding for three of four Ss. In the second experiment, the differential modeling procedure was introduced as an initial manipulation and was successful in establishing discriminative performance in all Ss. After several sessions of differential responding, the observation of a model performing nondifferentially was relatively ineffective in altering the pattern of responding. These results suggest (1) that modeling may be functional in altering a S's behavior depending on what point in the procedures the manipulation is introduced and (2) that certain procedural variables may define a functional response class characterized by the failure to develop discriminative responding.     

Auditory localization: The importance of eye movements and a textured visual environment

Two experiments were designed to investigate the factors involved in the visual facilitation of auditory localization. In both experiments, adult human Ss pointed to targets in a variety of visual conditions. The results of the first experiment showed that target-directed eye movements were important. In the second experiment, eye localization was assessed, along with pointing localization. Both eye and hand localization of the hidden auditory targets were better when target-directed eye movements were made in a lighted environment than when made in the dark. Data also suggested that Ss have better knowledge of their eye position in the light. Possible mechanisms for the involvement of eye movements were suggested, and the theoretical importance of the results was discussed.