When remembering and perceiving collide: the effect of visual distraction on long term memory retrieval

Abstract

In seeking to retrieve goal-relevant information from long-term memory we face many obstacles that place demands on top-down cognitive control. Some of the obstacles are internal: there may be one or many associated mnemonic contenders for a target memory, or target memory representation may itself be weak. Other obstacles are external: our attention may be captured by environmental distracting perceptual events. Yet little is known about if, or how, these internal and external obstacles jointly influence successful memory retrieval. In three sets of experiments, we investigated the effects of internal interference (selection demand and retrieval demand) and external perceptual distraction on long-term memory retrieval. To test the generality of the effects, and to enhance ecological validity, we examined both semantic and episodic memory retrieval, used both static and dynamic visual distraction, and employed both abstract and semantically meaningful scenes as distraction images.For both the episodic and the semantic memory tasks, we found, in line with previous research, that as internal mnemonic competition increased, retrieval accuracy decreased and retrieval time increased, and, as the association strength between a given retrieval cue and a target memory increased, retrieval accuracy increased and retrieval time decreased. Unlike previous findings, visual distraction resulted in small effects on memory accuracy (average effect size d of .25), whereas it resulted in large effects on memory retrieval time (average effect size d of .99, average response cost of 135ms). Notably, there was little evidence that perceptual distraction imposed greater costs when there were many internal memory contenders (high selection demand) or when the target memory was weak (high retrieval demand). The non-interactive effects suggest a type of serial gating effect in which external perceptual versus internal mnemonic calls on our attentional resources are met successively (or alternately) rather than simultaneously. From a practical standpoint, particularly where decisions and actions need to be taken quickly, visual distraction should be minimized. Visual distraction may impede our ready and fluent access to even well-learned information, with implications for cognitive performance in contexts ranging from classrooms to emergency rooms, from creative idea generation sessions to witness testimony in legal settings.