When temporal isolation benefits memory for serial order

According to temporal distinctiveness models, items that are temporally isolated from their neighbors during list presentation are more distinct and thus should be recalled better. Contrary to that expectation of distinctiveness views, much recent evidence has shown that forward short-term serial recall is unaffected by temporal isolation. We report two experiments using reconstruction of order tasks that confirmed that when report order is strictly forward, temporal isolation does not benefit performance. However, both experiments also showed that when report order is unconstrained, temporal isolation does benefit performance. The differences between forward and unconstrained report were found to be independent of whether or not people can anticipate the type of test at encoding. The presence and absence of isolation effects under two different conditions, both requiring memory for order, challenges many existing theories of memory but is compatible with the idea that multiple differentially weighted types of information contribute to memory retrieval.