Practice effects on two memory retrievals from a single cue.

The effects of practice on 2 retrievals from a single cue were investigated. In Experiment 1, participants were given extended single-task practice and were then tested on a dual memory retrieval task. Perfomance was consistent with a sequential retrieval model proposed by T. C. Rickard and H. Pashler (2003). In Experiment 2, participants practiced both single- and dual-retrieval tasks extensively. Initially, data from all participants indicated sequential retrieval. However, participants who grouped the 2 response outputs were eventually able to perform the dual task with a latency that approached the prediction of a parallel race model. Models that assume a transition from sequential to parallel retrieval with practice, along with other models that assume an immutable retrieval bottleneck at all practice levels, are considered.