Temporal isolation does not facilitate forward serial recall—or does it?

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.     

Memory Without Consolidation: Temporal Distinctiveness Explains Retroactive Interference

Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to‐be‐remembered (TBR) information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interference. The cognitive neuroscience literature has suggested neural consolidation is a pivotal factor determining item recall. According to this account, interfering activity interrupts consolidation processes that would otherwise stabilize the memory representations of TBR items post‐encoding. Temporal distinctiveness theory, by contrast, proposes that the retrievability of items depends on their isolation in psychological time. According to this theory, information processed after the encoding of TBR material will reduce the temporal distinctiveness of the TBR information. To test between these accounts, implementations of consolidation were added to the SIMPLE model of memory and learning. We report data from two experiments utilizing a two‐list free recall paradigm. Modeling results imply that SIMPLE was able to model the data and did not benefit from the addition of consolidation. It is concluded that the temporal gradient of retroactive interference cannot be taken as evidence for memory consolidation.     

Recall and recognition of order and item information in probed running memory, as a function of IQ

Two experiments were designed to test the possibility that correlations between IQ and probed serial running memory depend on IQ-related individual differences in the retention of order information in short-term memory. In Experiment I, correlations were obtained regardless of whether instructions emphasized serial recall or free recall. In Experiment II, a significant correlation between IQ and performance was obtained in a recognition test for very recent item information, but not in a recognition test for very recent order information. These data together with a theoretical analysis of the operations involved in the tasks, led to the conclusion that the correlations reflected individual differences in the capacity to access specified sets of items in very short-term memory.     

Evidence for time-based models of free recall

Is memory temporally organized? According to temporal distinctiveness models of memory, temporally isolated items should be better remembered than temporally crowded items in free recall tasks. Here, we tested this class of model by varying the temporal isolation of items either predictably (Experiment 1) or unpredictably (Experiment 2) in a free recall task. In both experiments, item recall probability increased as a function of the temporal gaps both before and after the item. The results are taken as support for temporal distinctiveness models of memory, in which items are represented and recalled in terms of their positions along a temporal dimension.     

Maximizing the benefits and minimizing the costs of repeated memory tests for older adults

Repeatedly trying to remember information can help people remember more but can also lead to inaccuracies. Two experiments examined whether the costs of repeated recall efforts can be minimized for older adults by using memory tests that require specification of the source of recalled items. Participants saw and imagined pictures and then took 3 successive recall tests in which they either indicated the source of each remembered item (source recall) or simply recalled the items without specification of their source (free recall). Results showed that recall increased systematically from Test 1 to Test 3, although the rate of increase was less marked for older adults, and older adults recalled less overall. After the free recall tests, older adults made more source misattributions (claiming to have seen imagined items) than did young adults, but after the source recall tests, age differences were not significant. Thus, repeatedly recalling items while considering their source was associated with benefits in terms of increased recall and fewer costs in terms of source errors.     

One,two, or three memories? A problem-solving approach to memory for performed acts

To test three theories of memory for performed acts, four sets of experiments were conducted. Two of the theories, the rehearsal obstruction theory and the multi-code representation theory, posit separate laws for recall of performed acts. The third, a problem-solving theory, attempts to explain act memory as well as memory for visually and verbally presented information within a unified conceptual framework. One set of experiments failed to demonstrate level-of-processing effects with free recall of performed tasks, thus providing evidence in support of the theories assuming distinct laws. The three other sets of experiments, which examined serial recall of performed acts, the effect of specified encoding instructions, and the role of contextual frames in free recall of acts, all gave results in support of the monistic problem-solving interpretation.     

Temporal–contextual processing in working memory: Evidence from delayed cued recall and delayed free recall tests

Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal–contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content–context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.     

Person memory and person judgments based on categorically organized information

Free recall, cued recall, and rating-like judgments — conceived as alternative modes of expressing memorized information — were assessed in a person memory task. The target person had been described with respect to the presence or absence of 48 different interests (e.g., Mozart, sonatas, tennis, boxing) in 12 interest categories (e.g., music, sports). The number of interests (vs non-interests) per category was manipulated as well as the order of the three sub-tasks. The pattern of results can be explained within a categorical coding framework which suggests two functionally independent stages of recall: (a) access to a higher-order memory code on the category level, and (b0 reconstruction of specific items within categories. In particular, judgments of the degree of interest in the abstract categories were only related to selective free recall on the categorical level but not specific level free recall. Cued recall of the degree of interest in specific items was only related to free recall on the specific level. Making the category judgments before the free recall task, rather than afterwards, increased the availability of categories but not specific items. And inconsistent patterns of interests impaired the cued recall of specific patterns within categories but did not affect the categorical level. A strong positivity effect (i.e., more interests recalled than non-interests) was also found, resembling the often noted advantage of positive information in other domains of cognitive psychology.     

States of awareness across multiple memory tasks: obtaining a "pure" measure of conscious recollection

Four experiments were conducted to examine the nature of recollective experience across different explicit memory tests. Experiments 1 and 2 showed that the proportion of retrieved items that were given Remember responses were equivalent across free recall, category cued recall, category plus letter cued recall, and recognition memory tests unlike the result reported by Tulving [Can. Psychol. 26 (1985) 1]. Experiments 3 and 4 revealed that Remember judgments are influenced by both conceptual and perceptual variables not only in the recognition task but in other explicit memory tasks as well. Taken together, the empirical evidence from this study demonstrates that explicit memory performance is accompanied by different states of awareness not only in recognition but also across other memory tasks including free recall.     

The fate of originally presented surface information following recall errors in sentence memory tasks

Pictures are remembered better than their names. This picture superiority effect in episodic memory has been attributed either to the greater sensory distinctiveness of pictures or to their greater conceptual distinctiveness. Weldon and Coyote (1996) tested the conceptual distinctiveness hypothesis by comparing how well pictures as opposed to words primed in two conceptual implicit memory tasks (category production and word association). They found no picture superiority in priming and concluded that the basis of the picture superiority effect must then be pictures' greater sensory distinctiveness. Using the same logic, we compared how well pictures as opposed to words primed in a perceptual implicit memory task (picture and word fragment identification). The sensory distinctiveness theory would predict that pictures should prime picture fragment identification better than words prime word fragment identification, a result we call the picture superiority in within-form priming. Across three experiments which manipulated the encoding task at study, only one showed picture superiority in within-form priming. In contrast, in all three experiments there was robust picture superiority in recall, and exposure to pictures and words at study and test produced independent effects in which both study and test exposure to pictures was more effective for recall than exposure to words. We consider how these results might be reconciled by differences in retrieval demands between recall and fragment identification.     

The role of chronic physical exercise and selective attention at encoding on implicit and explicit memory

Despite the evidence revealing benefits of chronic cardiovascular exercise on executive functions, little research has been conducted on long-term memory. We aimed to investigate the effect of physical exercise on implicit and explicit memory when attention was modulated at encoding in two groups of active and sedentary participants. With this purpose, attention was manipulated in a similar way in the implicit and explicit memory tasks by presenting picture outlines of two familiar objects, one in blue and the other in green, and participants were asked to pay attention only to one of them. Implicit memory was assessed through conceptual priming and explicit memory through a free recall task followed by recognition. The results did not reveal significant differences between groups in conceptual priming or free recall. However, in recognition, while both groups had similar discrimination for attended stimuli, active participants showed lower discrimination between unattended and new stimuli. These results suggested that exercise may have effects on specific cognitive processes, that is, that active participants may suppress non-relevant information better than sedentary participants, making the discrimination between unattended and new items more difficult.     

注意控制与短时记忆的知觉组织

、考察了短时记忆中的知觉组织是否受双作业时指导语引导的注意策略控制。各有24名北京大学本科生参加了自由回忆和顺序回亿实验。实验任务有2种：记忆和声音监控。声音监控或者安排在记忆编码阶段,或者安排在记忆提取阶段。双作业时的指导语类型有3种,分别强调记忆、声音监控或两种作业同样重要。记忆项目表分2种：不分组和知觉分组。研究发现：自由回忆中的知觉组织仅受编码阶段的指导语影响;顺序回忆中的知觉组织仅受提取阶段的指导语影响。作者设想,短时记忆中的知觉组织在编码和提取阶段都受注意控制,但记忆类型不同,注意控制的作用地点和表现形式也有所不同。     

Sequential dependencies in recall of sequences: Filling in the blanks

Sequential dependencies can provide valuable information about the processes supporting memory, particularly memory for serial order. Earlier analyses have suggested that anticipation errors—reporting items ahead of their correct position in the sequence—tend to be followed by recall of the displaced item, consistent with primacy gradient models of serial recall. However, a more recent analysis instead suggests that anticipation errors are followed by further anticipation errors, consistent with chaining models. We report analyses of 21 conditions from published serial recall data sets, in which we observed a systematic pattern whereby anticipations tended to be followed by the “filling in” of displaced items. We note that cases where a different pattern held tended to apply to recall of longer lists under serial learning conditions or to conditions where participants were free to skip over items. Although the different patterns that can be observed might imply a dissociation (e.g., between short- and long-term memory), we show that these different patterns are naturally predicted by Farrell’s (Psychological Review 119:223–271, 2012) model of short-term and episodic memory and relate to whether or not spontaneously formed groups of items can be skipped over during recall.     

On the locus of the stimulus suffix effect

Two experiments contrasted short-term memory and sensory memory (precategorical acoustic storage) explanations of the stimulus suffix effect. Experiment 1 attempted to interfere with recency recall by forcing subjects to encode nonverbal acoustic suffixes into a verbal, articulatory code. Subjects in this condition showed recall that was comparable to that of subjects who were told to ignore the suffixes. However, Experiment 2 showed that silently mouthed articulation of a suffix can produce interference on recall of recency items, although not as much as that produced by vocal articulation. The results are discussed in terms of current models of the stimulus suffix effect.     

Monitoring the future: object and source memory for real and imagined events

In these experiments a memory‐monitoring decision is made, whereby subjects must decide not only whether or not to‐be‐learned stimuli will be remembered—the focus of all of the past research into the Judgement of Learning (JOL)—but also whether they will be able to assess the source of those stimuli, as assessed by a new measure, Judgement of Source (JOS). In Experiment 1 subjects had to judge whether they would remember the occurrence and the source of items that were either seen or imagined. Although seen items were better remembered and sourced than imagined, subjects were unable to predict this outcome: they underestimated their ability to recall seen items and overestimated their ability to recall imagined items. In Experiment 2 subjects had to discriminate between self‐performed or other‐performed enacted or imagined events. We expected that the motor cues associated with overt performance should provide more sensory information than had the visual input in Experiment 1, and this should help subjects to discriminate between real and imagined items. As predicted, JOL magnitude showed that subjects were now able to predict accurately that they would recall more enacted events than imagined events. JOS magnitude showed that subjects incorrectly predicted that self‐enactment would assist source memory compared to imagination. However, it was the source of other‐focused events which was more accurately remembered. The results are discussed in terms of Koriat's (1997) view about cue utility in making JOLs. Copyright © 1999 John Wiley & Sons, Ltd.     

The order of recall and the recall of order

Adelphi University, Garden City, Long Island, New York 11530 Four experiments are described. The first three lend support to the assertion that retrieval from short-term storage (STS) is improved, possibly to a maximum, if items are recalled in their originally presented order. In the fourth experiment a modified recall condition was introduced in which written position of recall reflected order information. Although the subject was not constrained to recall the items in order under this modified recall condition, both item and order retention increased in comparison to both free and serial recall conditions. Within the theoretical framework adopted, the results indicate that retrieval from STS is improved by recalling in order; while long-term storage (LTS) is reduced by the constraint to recall in order. However, LTS is increased by the retention of order information when recalling in order is not required.     

Depth of processing and memory organization

Summary The study examined the idea that the organization of information in memory varies depending on the depth of processing during input, as well as on the conditions for retrieval. Two types of memory organization are distinguished: Conceptual organization implies a hierarchical structure in which items are grouped according to a principled taxonomic system (e.g., cow — horse). Associative organization, in contrast, is based on direct links among the members of a group (e.g., cow — milk). Two experiments examined the propositions that conceptual relations require more effort to be encoded during learning and more effort to be utilized during remenbering than associative relations. In Experiment 1 a list of 28 words was used, which could be grouped into 14 conceptual categories or, alternatively, into 14 associative categories of two words each. The words were presented under either shallow or deep encoding conditions. Increased depth of encoding resulted in increased conceptual clustering but had little effect on amount of associative clustering. Similar amounts of associative and conceptual clustering were observed during early output positions, but conceptual clustering tended to increase with recall trials, suggesting that it might depend on the establishment of a retrieval schema. In Experiment 2, after memorizing a list of words, subjects recalled the words either with or without the requirement to perform a secondary task while recalling. Relative to the undisturbed recall condition, the secondary task condition indicated stronger associative than conceptual clustering. The results were seen to support the idea that different types of memory organization may become salient under different attentional conditions.     

The item-order hypothesis reconsidered: The role of order information in free recall

According to the item-order approach of free recall, in pure short lists the free recall of unrelated items is organized according to their order of presentation in the study list. The approach was applied in the present study to experimenter-performed tasks (EPTs) and subject-performed tasks (SPTs). It claims that EPTs provide better serial order information than SPTs. Consequently, free recall of EPTs should be more organized along the presentation order of the items than the free recall of SPTs. In three experiments, some specific aspects of this approach were studied. Firstly, it was demonstrated that serial retrieval is not strongly used spontaneously and that its use is overestimated in the literature because it is usually evoked by an order reconstruction test which follows free recall testing. Secondly, a serial retrieval strategy in free recall can be encouraged by explicit instructions. Finally, the present experiments showed that a serial output strategy alone does not allow one to predict performance in free recall. The implications of these findings for the item-order approach will be discussed.     

Conditions and consequences of maintenance rehearsal.

The present experiments investigated the idea that the anticipated delay to initial recall governs whether a subject will rely on elaborative or maintenance rehearsal. In agreement with earlier research, the results suggested that maintenance rehearsal is used only when words can be rehearsed up to the moment of recall. A novel finding concerned the accessibility of the items processed in that way. When subjects were explicitly asked to recall those items first in final free recall, they were as likely to be recalled as items that had been processed elaboratively. This finding suggests that even rote rehearsal creates an accessible memory trace, albeit one that is most efficiently accessed by contextual rather than semantic cues.     

Recall cues interfere with retrieval from visuospatial working memory

Visuospatial working memory allows us to hold multiple visual objects over short delays. It is typically tested by presenting an array of objects, then after a delay showing a ‘probe’ indicating which memory item to recall or reproduce by adjusting a target feature. However, recent studies demonstrate that information at the time of probe can disrupt recall. Here, in three experiments we test whether traditional memory probes, which contain features that compete with the feature to be recalled, may themselves interfere with performance. We asked participants to report the direction of one of the several coloured arrows in memory, based on its colour. First, we demonstrate that recall is better when the probe is initially just a coloured dot, rather than a coloured arrow which has to be adjusted to match orientation memory, consistent with interference from features of the probe itself. Second, this interference is present even when a mask follows the memory array, suggesting that the interference does not work by degrading immediate or iconic memory. Finally, when items are shown sequentially, the first and last items are invulnerable to probe interference. Our findings support recent theories of associative recall, in which probes reactivate features in WM, retrieving information by pattern completion.