Evidence for time-based models of free recall

Memory & Cognition, 2008

In numerous recent studies in short-term memory, it has been established that forward serial recall is unaffected by the temporal isolation of to-be-remembered items. These findings contradict the temporal distinctiveness view of memory, which expects items that are temporally isolated from their neighbors to be more distinct and hence remembered better. To date, isolation effects have only been found with tests that do not constrain output order, such as free recall. This article reports two experiments that, for the first time, report a temporal isolation effect with forward serial recall, using a running memory task in which the end of the list is unpredictable. The results suggest that people are able to encode and use temporal information in situations in which positional information is of little value. We conclude that the overall pattern of findings concerning temporal isolation supports models of short-term memory that postulate multidimensional representations of items.

Journal of Memory and Language, 2008

According to temporal distinctiveness models, items that are temporally isolated from their neighbors during list pre-10 sentation are more distinct and thus should be recalled better. Contrary to that expectation of distinctiveness views, 11 much recent evidence has shown that forward short-term serial recall is unaffected by temporal order tasks that con-12 firmed that when report order is strictly forward, temporal isolation does not benefit performance. However, both 13 experiments also showed that when report order is unconstrained, temporal isolation does benefit performance. The 14 differences between forward and unconstrained report were found to be independent of whether or not people can antic-15 ipate the type of test at encoding. The presence and absence of isolation effects under two different conditions, both 16 requiring memory for order, challenges many existing theories of memory but is compatible with the idea that multiple 17 differentially weighted types of information contribute to memory retrieval. 18

Journal of Memory and Language, 2006

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. Event-based theories, by contrast, deny that time plays a role at encoding and predict no beneficial effect of temporal isolation, although they acknowledge that a pause after item presentation may afford extra opportunity for a consolidation process such as rehearsal or grouping. We report two experiments aimed at differentiating between the two classes of theories. The results show that neither serial recall nor probed recall benefit from temporal isolation, unless participants use pauses to group a list. Simulations of the SIMPLE model provide convergent evidence that short-term memory for serial order need not involve temporal representations.

Bulletin of the Psychonomic Society, 1974

Memory & Cognition, 2010

Recent temporal distinctiveness models of memory predict that temporally isolated items will be recalled better than temporally crowded items. The effect has been found in some tasks (free recall; memory for serial order when report order is unconstrained; running memory span) but not in others (forward serial recall). Such results suggest that the attentional weighting given to a temporal dimension in memory may vary with task demands. Here we find robust temporal isolation effects in recognition memory (Experiment 1) and a smaller isolation effect in forward serial recall when an open pool of items is used (Experiment 2). Analysis of 26 temporal isolation effects suggests that the phenomenon occurs in a range of tasks but is larger when it is useful to attend to a temporal dimension in memory. The overall pattern of results is taken to favor memory models that rely on multiple weighted dimensions in memory, one of which is temporal.

Journal of Experimental Psychology: Learning, Memory, and Cognition, 2010

In four experiments, participants were presented with lists of between 1 and 15 words for tests of immediate memory. In each experiment, participants tended to initiate recall with the first word on the list for short lists, but as the list length was increased so there was a decreased tendency to start with the first list item; and, when free to do so, participants showed an increased tendency to start with one of the last four list items. In all conditions, the start position strongly influenced the shape of the resultant serial position curves: when recall started at serial position 1, elevated recall of early list items was observed; when recall started towards the end of the list, there were extended recency effects. These results occurred under free recall, and different variants of immediate serial recall (ISR) and reconstruction of order tasks. We argue that these findings have implications for the relationship between recall and rehearsal and free recall and ISR.

Psychonomic Bulletin & …, 2007

Memory & Cognition, 2006

The notion of a link between time and memory is intuitively appealing and forms the core assumption of temporal distinctiveness models. Distinctiveness models predict that items that are temporally isolated from their neighbors at presentation should be recalled better than items that are temporally crowded. By contrast, event-based theories consider time to be incidental to the processes that govern memory, and such theories would not imply a temporal isolation advantage unless participants engaged in a consolidation process (e.g., rehearsal or selective encoding) that exploited the temporal structure of the list. In this report, we examine two studies that assessed the effect of temporal distinctiveness on memory, using auditory (Experiment 1) and auditory and visual (Experiment 2) presentation with unpredictably varying interitem intervals. The results show that with unpredictable intervals temporal isolation does not benefit memory, regardless of presentation modality.

Journal of Experimental Psychology: Learning, Memory, and Cognition, 1999

In-immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (1996) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls.

Journal of Memory and Language, 2008

The spacing effect is the commonly observed phenomenon that memory for spaced repetitions is better than memory for massed repetitions. To further investigate the role of rehearsal in spacing effects, three experiments were conducted. With pure lists we found spacing effects in free recall when spacing intervals were relatively long (Experiments 1, 2 and 3), but not when spacing intervals were relatively short (Experiments 2 and 3). In contrast, with mixed lists spacing effects emerged at both short spacing intervals and long spacing intervals (Experiment 3). Additional analyses on the combined pure-list data revealed that the correlation between the primacy advantage and the spacing effect in Quadrants 2 through 4 was positive for all-massed lists and negative for all-spaced lists. This provides some first evidence for the zero-sum nature of the spacing effect in pure lists. The need to incorporate assumptions about rehearsal in theories of spacing is discussed.