Delayed reward, delay-box confinement, and instrumental performance: a within-type design.

Summnry.-Three experiments were done on delayed reinforcement and extinction using a within-group design in training. Entering one alley of a Grice discrimination apparatus led to immediate reward, while entering the other led to 40-sec. delays either on 50% of the trials (Exps. I and 11) or on 100% of the trials (Exp. 111). Half of Ss were extinguished in the non-delay alley, half in the delay alley. Half of Ss in each extinction group were extinguished without delay-box confinement, half with 40-sec. delay-box confinement on 50% of the trials (Exps. I and 11) or 100% of the trials (Exp. 111). In all three experiments Ss learned to discriminate between the delay and non-delay alleys. In Exp. I Ss ran significantly faster in extinction in the non-delay alley. The same trend was evident in Exps. I1 and 111. Thus, the results were in the opposite direction to those which have been found in between-group smdies. In Exp. 111 Ss with 100% delay-box confinement in extinction ran slower ( . l o > P > .O5) than Ss without confinement.