Forgotten but not gone: Context effects on recognition do not require explicit memory for context

Context effects on recognition memory provide an important indirect assay of associative learning and source memory. Neuropsychological studies have indicated that such context effects may obtain even if the contexts themselves are not remembered—for example, in individuals impaired on direct tests of memory for contextual information. In contrast, a recent study indicated that the effects of temporal context reinstatement on visual recognition obtain only when the contextual information itself was explicitly recollected. Here we report that the effects of reinstatement of spatial-simultaneous context on visual object recognition memory obtain irrespective of whether those context stimuli are explicitly recognized. We suggest that spatial-simultaneous context effects might be based on ensemble unitization of target and context stimuli at encoding, whereas temporal context effects may require recollective processes.     

Generation disrupts memory for intrinsic context but not extrinsic context

Although generation typically enhances item memory, the effect is subject to a number of theoretically important limitations. One potential limitation concerns context memory but there has been debate about whether generation actually enhances or disrupts memory for contextual details. Five experiments assessed the effect of generation on context memory for perceptual attributes of the study stimulus (intrinsic context). The results indicate that despite enhancing item memory, generation disrupts memory for intrinsic context. This result generalized over different intrinsic details (print colour and font), different generation manipulations, and several methodological factors identified in earlier research as potential moderators of this negative generation effect. Despite the negative generation effect on intrinsic context, contextual details external to the target item (extrinsic context) are not disrupted. In a sixth experiment, a visually based generation task (letter transposition) enhanced context memory for the extrinsic detail of location. Coupled with earlier research, the results indicate that generation disrupts context memory for intrinsic details but either does not harm or enhances memory for extrinsic context.     

Non-abstractive global-matching models: A framework for investigating the distinctiveness effect on explicit and implicit memory

One very well-known memory phenomenon is the observation that if a specific item seems to be different or rare in any way from other items present in the same encoding context, this item is likely to be remembered more accurately. This phenomenon, named the von Restorff effect or the isolation effect, has been known since 1933 and been considered today as one of the possible ways to create distinctiveness. The aim of this article is to report that the current debate concerning its non-emergence in implicit memory tasks is directly due to a theoretical disagreement about the nature of human memory. In this paper, we conclude that non-abstractive global-matching models can provide an effective theoretical framework for the study of the distinctiveness effect with isolation both in implicit and explicit memory tasks.     

Dissociation and memory suppression: A comparison of high and low dissociative individuals’ performance on the Think–No Think task

The present study examined whether high and low dissociative individuals differ in their ability to keep target stimuli out of their awareness (suppression) and how this relates to their memory of those targets during a later cued recall task. The prediction was that high dissociators display a general inability to focus attention and that their distractibility undermines successful suppression, thereby enhancing memory for suppressed items. College students with high (n = 35) and low (n = 33) scores on the Dissociative Experiences Scale participated in a Dutch version of Anderson and Green’s (2001) Think–No Think (TNT) task. Overall, a significant suppression effect emerged. However, no differences between high and low dissociators were observed. Thus, the present results do not confirm that dissociation is linked to heightened distractibility.     

心理负荷对元记忆监测准确性及偏差的影响

以汉字再认任务为载体, 采用两因素被试内设计, 考察任务所导致的心理负荷水平, 以及学习判断(JOL)和信心判断(JOC)两种监测方式, 对元记忆监测效果的影响。对监测效果的衡量分别使用了相对准确性, 绝对准确性, 以及判断偏差三种指标。结果发现, 个体在任务过程中的心理负荷水平会影响其对任务解决过程的监测准确性:心理负荷水平越高, 元记忆监测的准确性越低。心理负荷水平还会影响元记忆监测的判断偏差:心理负荷处于中等偏低水平时, 监测不容易出现偏差;心理负荷处于中等偏高水平时, 个体表现出过高自信;但当心理负荷达到较高水平后, 判断偏差消失;随着心理负荷水平继续增大, 个体又表现出过低自信。     

Negative emotion elicited in high school students enhances consolidation of item memory,but not source memory

The study examined the effect of negative emotion on consolidation of both item and source memory. Participants learned words read by either a male or female. Then they watched either a negative or a neutral video clip. Memory tests were carried out either 25 min or 24 h after learning. The study yielded the following findings. First, negative emotion enhanced consolidation of item memory as measured by recognition memory in the 25-min delay, and enhanced consolidation of item memory as measured by free recall in both the 25-min and the 24-h delay. Second, negative emotion had little effect on consolidation of source memory, either in the 25-min or the 24-h delay. These findings provide evidence for the differential effects of negative emotion on item memory and source memory and have implications for using emotion as a strategy to intervene memory consolidation.     

How you ask matters: An experimental investigation of the influence of mood on memory self-perceptions and their relationship with objective memory

Stronger relationships often emerge between mood and memory self-efficacy (MSE) than between MSE and memory abilities. We examined how social desirability, mood congruency and framing influence the mood–MSE relationship. Social desirability correlated with all self-report measures, and covarying social desirability diminished the mood-MSE relationship while enhancing the relationship between MSE and objective memory. Participants rated their memory more harshly on positively than neutrally or negatively worded MSE items. Current mood state did not affect MSE overall or when items were worded positively or neutrally. However, on negatively worded items, participants in a negative mood exhibited lower MSE than participants in a positive mood. Thus, both MSE and the mood–MSE relationship depended upon question wording. These results indicate that controlling social desirability and item framing on MSE questionnaires may reduce their confounding influence on memory self-perceptions and the influence of mood on self-reported abilities, allowing subjective memory to more accurately reflect objective memory in healthy and clinical populations.     

The influence of contour fragmentation on recognition memory: an event-related potential study

The present study was carried out to examine how the event-related potentials to fragmentation predict recognition success. Stimuli were abstract meaningless figures that were either complete or fragmented to various extents but still recoverable. Stimuli were first encoded as part of a symmetry discrimination task. In a subsequent recognition phase, encoded stimuli were presented complete along with never presented stimuli and participants performed an old/new discrimination task. Fragmentation stimuli elicited more negative ERPs than complete figures over the frontal, central and parietal areas between 180 and 260 ms, and over the occipito-temporal areas between 220 and 340 ms. Only this latter effect was modulated as a function of whether stimuli were recognized or not during the recognition phase of the memory test. More specifically, the effect occurred for stimuli that were later forgotten and was absent for stimuli that were later recognized. This ERP to fragmentation, the occipito-temporal N(frag), possibly reflects the brain response to encoding difficulty, and is thus predictive of recognition performance.     

Time and resource limits on working memory: cross-age consistency in counting span performance

This longitudinal study separated resource demand effects from those of retention interval in a counting span task among 100 children tested in grade 2 and again in grades 3 and 4. A last card large counting span condition had an equivalent memory load to a last card small, but the last card large required holding the count over a longer retention interval. In all three waves of assessment, the last card large condition was found to be less accurate than the last card small. A model predicting reading comprehension showed that age was a significant predictor when entered first accounting for 26% of the variance, but counting span accounted for a further 22% of the variance. Span at Wave 1 accounted for significant unique variance at Wave 2 and at Wave 3. Results were similar for math calculation with age accounting for 31% of the variance and counting span accounting for a further 34% of the variance. Span at Wave 1 explained unique variance in math at Wave 2 and at Wave 3.     

Post-encoding emotional arousal enhances consolidation of item memory,but not reality-monitoring source memory

The current study examined whether the effect of post-encoding emotional arousal on item memory extends to reality-monitoring source memory and, if so, whether the effect depends on emotionality of learning stimuli and testing format. In Experiment 1, participants encoded neutral words and imagined or viewed their corresponding object pictures. Then they watched a neutral, positive, or negative video. The 24-hour delayed test showed that emotional arousal had little effect on both item memory and reality-monitoring source memory. Experiment 2 was similar except that participants encoded neutral, positive, and negative words and imagined or viewed their corresponding object pictures. The results showed that positive and negative emotional arousal induced after encoding enhanced consolidation of item memory, but not reality-monitoring source memory, regardless of emotionality of learning stimuli. Experiment 3, identical to Experiment 2 except that participants were tested only on source memory for all the encoded items, still showed that post-encoding emotional arousal had little effect on consolidation of reality-monitoring source memory. Taken together, regardless of emotionality of learning stimuli and regardless of testing format of source memory (conjunction test vs. independent test), the facilitatory effect of post-encoding emotional arousal on item memory does not generalize to reality-monitoring source memory.     

The functions of autobiographical memory: An integrative approach

Recent research in cognitive psychology has emphasised the uses, or functions, of autobiographical memory. Theoretical and empirical approaches have focused on a three-function model: autobiographical memory serves self, directive, and social functions. In the reminiscence literature other taxonomies and additional functions have been postulated. We examined the relationships between functions proposed by these literatures, in order to broaden conceptualisations and make links between research traditions. In Study 1 we combined two measures of individual differences in the uses of autobiographical memory. Our results suggested four classes of memory functions, which we labelled Reflective, Generative, Ruminative, and Social. In Study 2 we tested relationships between our four functions and broader individual differences, and found conceptually consistent relationships. In Study 3 we found that memories cued by Generative and Social functions were more emotionally positive than were memories cued by Reflective and Ruminative functions. In Study 4 we found that reported use of Generative functions increased across the lifespan, while reported use of the other three functions decreased. Overall our findings suggest a broader view of autobiographical memory functions that links them to ways in which people make meaning of their selves, their environment, and their social world more generally.     

An analogue study of the effects of Psychological Debriefing on eyewitness memory

Sixty-one participants from the community participated in a randomised controlled trial of group debriefing to assess the effect of this intervention upon memory for a stressful event. Participants were randomly allocated to one of three groups: debriefing; debriefing with an experimenter confederate present (who supplied three pieces of misinformation to the group regarding the stressful event); and a no-treatment control. All groups were shown a very stressful video and were again reviewed after 1 month. Members of the debriefing group where a confederate provided misinformation were more likely to recall this misinformation as fact than members of the other two groups. The debriefing group was also more accurate in their recall of peripheral content than the confederate group. Across all groups, participants were found to be more accurate at central rather than peripheral recall yet more confident for incorrect memories of the video than correct memories.     

Rewarded remembering: dissociations between self-rated motivation and memory performance

People often claim that they perform better in memory performance tasks when they are more motivated. However, past research has shown minimal effects of motivation on memory performance when factors contributing to item-specific biases during encoding and retrieval are taken into account. The purpose of the present study was to examine the generality of this apparent dissociation by using more sensitive measures of experienced motivation and memory performance. Extrinsic motivation was manipulated through competition instructions, and subjective ratings of intrinsic and extrinsic motivation were obtained before and after study instructions. Participants studied a series of words, and memory performance was assessed by content recall (Experiment 1) and source recall (Experiment 2). Both experiments showed dissociation between subjective ratings of extrinsic motivation and actual memory performance, so that competition increased self-rated extrinsic motivation but had no effects on memory performance, including source recall. Inconsistent with most people's expectations, the findings suggest that extrinsic motivation has minimal effects on memory performance.     

Prospective memory training in young adults enhances trained-task but not transfer-task performance

ABSTRACT

Training and transfer effects of prospective memory training have not been assessed in healthy young adults yet. The present study examined the effects of an 8-day prospective memory training programme using the Virtual Week computer game in 18–24-year-old students. Using the performance of an active control group as comparison, the study revealed a significant short-lived beneficial training-induced effect on a nearest-transfer task consisting of a different version of the trained task. No evidence was obtained for transfer effects to other tasks measuring prospective memory (near transfer), or to tasks measuring various executive functions or general intelligence (far transfer). These results were compared to those from a previous study in which an identical training and testing protocol was used in 13–15-year-old adolescents. This study did reveal some evidence of near and far transfer. The results of the two studies combined suggest a greater potential for prospective memory training to induce beneficial transfer effects in young adolescents than in young adults.     

Time-limited effects of emotional arousal on item and source memory

Two experiments investigated the time-limited effects of emotional arousal on consolidation of item and source memory. In Experiment 1, participants memorized words (items) and the corresponding speakers (sources) and then took an immediate free recall test. Then they watched a neutral, positive, or negative video 5, 35, or 50?min after learning, and 24 hours later they took surprise memory tests. Experiment 2 was similar to Experiment 1 except that (a) a reality monitoring task was used; (b) elicitation delays of 5, 30, and 45?min were used; and (c) delayed memory tests were given 60?min after learning. Both experiments showed that, regardless of elicitation delay, emotional arousal did not enhance item recall memory. Second, both experiments showed that negative arousal enhanced delayed item recognition memory only at the medium elicitation delay, but not in the shorter or longer delays. Positive arousal enhanced performance only in Experiment 1. Third, regardless of elicitation delay, emotional arousal had little effect on source memory. These findings have implications for theories of emotion and memory, suggesting that emotion effects are contingent upon the nature of the memory task and elicitation delay.     

Dissociations between implicit and explicit memory in children: the role of strategic processing and the knowledge base

A review of the literature shows that explicit memory develops substantially from three years of age to adulthood, while implicit memory remains stable across this age range. Previously, this developmental dissociation has been attributed to different memory systems, or to confounds with perceptual vs. conceptual processing. Prompted by an alternative developmental framework, the experiments reported here provide evidence against both interpretations. Instead, it will be argued that (a) the implicit-explicit developmental dissociation reflects differences in strategic processing (strategy use and metamemory) across childhood and (b) that implicit memory can show development if a child's knowledge base in the tested domain is developing with age.     

The effects of sleep on episodic memory in older and younger adults

Evidence on sleep-dependent benefits for episodic memory remains elusive. Furthermore we know little about age-related changes on the effects of sleep on episodic memory. The study we report is the first to compare the effects of sleep on episodic memories in younger and older adults. Memories of stories and personal events were assessed following a retention interval that included sleep and following an equal duration of wakefulness. Both older and younger adults have superior memory following sleep compared to following wakefulness for both types of material. Amount of forgetting of personal events was less during wakefulness in older adults than in younger adults, possibly due to spontaneous rehearsal. Amount of time spent sleeping correlated highly with sleep benefit in older adults, suggesting that quantity of total sleep, and/or time spent in some stages of sleep, are important contributors to age-related differences in memory consolidation or protection from interference during sleep.     

Attentional effects on orientation judgements are dependent on memory consolidation processes

Are the effects of memory and attention on perception synergistic, antagonistic, or independent? Tested separately, memory and attention have been shown to affect the accuracy of orientation judgements. When multiple stimuli are presented sequentially versus simultaneously, error variance is reduced. When a target is validly cued, precision is increased. What if they are manipulated together? We combined memory and attention manipulations in an orientation judgement task to answer this question. Two circular gratings were presented sequentially or simultaneously. On some trials a brief luminance cue preceded the stimuli. Participants were cued to report the orientation of one of the two gratings by rotating a response grating. We replicated the finding that error variance is reduced on sequential trials. Critically, we found interacting effects of memory and attention. Valid cueing reduced the median, absolute error only when two stimuli appeared together and improved it to the level of performance on uncued sequential trials, whereas invalid cueing always increased error. This effect was not mediated by cue predictiveness; however, predictive cues reduced the standard deviation of the error distribution, whereas nonpredictive cues reduced “guessing”. Our results suggest that, when the demand on memory is greater than a single stimulus, attention is a bottom-up process that prioritizes stimuli for consolidation. Thus attention and memory are synergistic.     

Effect of delay on children's delay-execute prospective memory performance

To date, little work has been done investigating prospective memory in children, particularly using a delay-execute paradigm. Two experiments were conducted to investigate this issue with children aged 5–11 years. While playing a computer driving game, children's ability to carry out a delayed intention either immediately a target cue appeared or after an additional delay, was assessed. These findings supported the few previous studies in this area by showing that preschool children are able to perform event-based prospective memory tasks. The results also extended these findings by demonstrating the impact of briefly delaying the execution of a retrieved intention, and revealing that there were important improvements in prospective memory performance from early to late childhood. The suggestion is made that executive resources may be responsible for this pattern of performance.     

Prospective memory in young and older adults: The effects of ongoing-task load

ABSTRACT

Prospective memory involves remembering to perform intended actions in the future. Previous work with the multinomial model of event-based prospective memory indicated that adult age-related differences in prospective-memory performance were due to the prospective (not the retrospective) component of the task (Smith & Bayen, 2006 Smith, R. E. and Bayen, U. J. 2006. The source of age differences in event-based prospective memory: A multinomial modeling approach. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32: 623–635. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar], Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 623). However, ongoing-task performance was also lower in older adults in that study. In the current study with young and older adults, the difficulty of the ongoing task was manipulated by varying the number of colors per trial to create easier and harder versions of the ongoing task for each age group. The easier version included 2 colors per trial for older adults and 4 colors for young adults. The harder version included 4 colors for older adults and 6 colors for young adults. By adjusting the ongoing-task difficulty, older adults were able to perform the ongoing task as well or better than the young adults. Analyses with the multinomial model revealed that making the ongoing task easier for older adults (or more difficult for young adults) did not eliminate age-related differences in prospective-memory performance and the underlying prospective component.