The effect of modality shifts on proactive interference in long-term memory

Two experiments examined the effects of shifts in the modality on proactive interference in long-term memory. In Experiment 1 subjects learned a 40-word list presented in one of two forms of auditory/visual change—blocked or random. In the blocked conditions, learners were presented half the words in one modality followed by the remaining 20 words in the other modality. Subjects in random conditions also received 20 nouns in each modality, but the presentation was random. Following a delay, all subjects completed an 80-item recognition test. Analysis of these data showed a definite effect (p < .001) for the random change in modality when compared to the blocked presentation. As predicted, distinct reduction in serial position effects was found with the modality of presentation was random. In contrast, the blocked presentation produced two well-defined serial position curves. In Experiment 2 the effects of a shift in the modality of presentation on proactive interference were studied with high and low conceptual rigid subjects. Four similar prose passages were presented with a modality shift taking place in the last passage in a shift condition. Subjects in nonshift conditions were presented the passages exclusively in either the auditory or visual mode. The results showed that a shift in the modality of presentation of a prose passage provided a powerful releaser from proactive interference. The superior performance of rigid thinkers regardless of experimental group membership was explained in terms of organizational memory strategies.