Accurate Delayed Matching-to-Sample Responding without Rehearsal: An Unintentional Demonstration with Children.

Research on joint control has focused on mediational responses, in which simultaneous stimulus control from two sources leads to the emission of a single response, such as choosing a comparison stimulus in delayed matching-to-sample. Most recent studies of joint control examined the role of verbal mediators (i.e., rehearsal) in evoking accurate performance. They suggest that mediation is a necessity for accurate delayed matching-to-sample responding. We designed an experiment to establish covert rehearsal responses in young children. Before participants were taught such responses; however, we observed that they responded accurately at delays of 15 and 30 s without overt rehearsal. These findings suggest that in some cases, rehearsal is not necessary for accurate responding in such tasks.