Presentation modality and proactive interference in short-term retention using a mixed-morality distractor task

Abstract

Two experiments investigated the release from PI following a shift in mode of presentation of the study words. In each experiment, the interpolated task required processing of both auditory (A) and visual (V) information. The results were the same with mixed Iists (Experiment I) and with independent groups (Experiment 11): Arelease from PI was obtained following an A to V shift but not following a V to A shift. 1t was concluded that the mixed-modality filler task has functional characteristics very similar to those of an A filler and that the filler task influences the mernory code for study items. Hopkins, Edwards, and Gavelek (1971) showed that a shift in mode of presentation from visual (V) to auditory (A) produced arelease from proactive interference (PI) in the paradigm developed by Wickens and his coworkers (Wickens, 1970(Wickens, , 1972. However, a shift in the A to V direction did not result in release from PI. These results seemed particularly important because of their potential implications for the encoding of modality information in the short-term store and because this was the only known situation in which an asymmetrical release from PI was obtained (Wickens, 1972). However, Hopkins et al used only a V filler task, and Hopkins, Edwards, and Cook (1973) subsequently showed that mode of presentation of the distractor task interacts with the presentation modality of the study items, both in determining overall retention and in producing a release from PI. In the latter study, it was found that short-term retention of V words is better with an A filler task than with an interpolated task presented in the V mode, but A words are better retained with a V than with an A flller. More importantly for present purposes, when the filler items are presented in the V mode, as in the earlier Hopkins et al (1971) experiments, arelease from PI is obtained following a V to A shift but not following an A to V shift in the mode of presentation of the study words; with an A filler task, on the other hand, release from PI is obtained only for an A to V shift in presentation modality of the study words. The experiments reported here used a mixed-mode interpolated task to explore further the role of the rehearsal-prevention activity in the encoding of A and V study words.For the filler task of the present experiments, pairs of digits were presented at a rapid rate and S was to report the sum for each pair. The digits of a pair were presented simultaneously, one in the A mode and one in the V mode. Thus, each filler item required processing of both A and V informaticn. On the basis of the effects of filler mode described by Hopkins et al (1973), it seemed reasonable to assurne that this type of interpolated task should interfere equally with the retention of A and V information. To the extent that arelease from PI is obtained, it should be symmetrical and may be taken as evidence for differential encoding of A and V study words. If no release from PI were obtained, it could be inferred that A and V study words are similar...