This review focuses on the results obtained using dual-task paradigms and explains how animal studies help to elucidate the neural mechanisms of interference control. Behavioral analyses of the interference effect in dual-task conditions have been conducted in studies using animals (Table 1). Although these experiments were conducted under dual-task conditions, some examined the functional similarity of short-term memory (STM) processes between humans and animals, rather than the psychological mechanisms related to dual-task interference. In humans, rehearsal is negatively affected when a secondary task is introduced during the retention
period of the primary STM task. Therefore, if the STM is a functionally equivalent Microtubule Associated inhibitor process in humans and animals, a similar negative effect on the rehearsal process would be expected in behavioral performance of dual tasks in animals. Moise
[9] examined find more this issue using monkeys. In the dual-task, a reaction time (RT) task was repeatedly inserted during the retention interval (<30 s) of a delayed matching-to-sample (DMS) task. In the RT task, monkeys were required to quickly touch an illuminated cue. The rationale was that, if the monkey's maintenance of memoranda relied on effortful rehearsal processes, the introduction of RT trials during the retention period should disrupt the performance of the DMS task, since effort was required to perform RT trials. In fact, DMS performance was markedly disrupted by the insertion of RT trials to a degree proportional to the number of inserted RT trials. The author concluded that the performance in both the DMS and RT required some degree of active processing which taxed a common capacity-limited cognitive resource, and that the nature of memory maintenance in DMS performance in monkeys was reminiscent of active rehearsal in human STM. On the other hand, Washburn and Astur [10] also investigated whether or not monkeys could rehearse visual short-term memoranda. They
inserted two secondary tasks during a variable retention interval (<48 s) in the DMS task. The secondary task was either manual tracking of a moving circle learn more or judgment of the number ‘2’. Insertion of these secondary tasks disrupted the performance of the DMS task. However, manual tracking produced no more disruptive effects than passive viewing of a moving circle, and the response times in the numerical judgment task were comparable during a retention interval and an intertrial interval of the DMS task. Therefore, the authors concluded that monkeys did not rely on active rehearsal processes to maintain memoranda. Although contradictory results have been obtained from experiments that examined the cross-species similarity of STM, these studies showed that, with the addition of relatively simple secondary tasks, a dual-task interference effect can be observed in monkeys.