Time to process information in working memory improves episodic memory

- Immediate recall of words from working memory is higher for simple than complex span.
- In contrast, episodic memory is higher for words studied in complex span than simple span.
- This episodic benefit is not due to the effort imposed by distractor processing in complex span.
- Episodic memory improves when individual words are attended for a longer period in working memory.

In simple-span tasks, participants encode items sequentially for immediate serial recall. Complex-span tasks are similar, except that items are interleaved with a distraction task. Whereas immediate memory is higher in simple than complex span, in tests of episodic long-term memory, better recall for words studied in complex than simple span has been observed (McCabe, 2008). This McCabe effect has been explained by assuming that distraction displace items from working memory, forcing people to covertly retrieve items after each distraction, thereby generating better episodic retrieval-cues than during simple span. Our experiments support an alternative hypothesis: individual words are attended to and processed longer in working memory in complex-span than in simple-span trials. We reduced the presentation rate of words in simple span, creating a “slow span” condition. Across four experiments, slow span improved episodic memory compared to simple span, and this benefit was larger than the McCabe effect.