回忆任务对合作抑制和错误修剪的调节——情绪效价和编码水平的影响

前人在项目回忆条件的合作记忆研究中记录到明显的合作抑制和错误修剪,背景提取条件的相关研究尤显不足;同时,情绪效价和编码水平对两类现象调节的研究尚未涉及。为此,本文在两个实验中采用经典合作记忆研究范式,以不同情绪效价的词汇为实验材料并以词汇在学习阶段的呈现颜色为背景展开研究。实验1和实验2分别在学习阶段采用了深编码和浅编码任务,回忆阶段则均含项目回忆(回忆已学词汇)和背景提取(回忆词汇在学习阶段的呈现颜色)两种任务。采用深编码条件的实验1的结果显示,项目回忆比背景提取条件的合作抑制更强、错误修剪更弱,回忆任务与词汇情绪效价交互影响合作抑制强度;采用浅编码条件的实验2则发现错误修剪在两种任务间的差异不显著。两实验的联合分析显示,回忆任务与编码水平交互影响合作抑制和错误修剪强度。上述结果表明:回忆任务对合作抑制和错误修剪的调节支持双重加工模型;回忆任务与情绪效价对合作抑制强度的交互影响支持权衡说,且与双重加工模型相吻合;回忆任务与编码水平交互影响合作抑制和错误修剪强度。     

“Going episodic”: collaborative inhibition and facilitation when long-married couples remember together

Two complementary approaches to the study of collaborative remembering have produced contrasting results. In the experimental “collaborative recall” approach within cognitive psychology, collaborative remembering typically results in “collaborative inhibition”: laboratory groups recall fewer items than their estimated potential. In the cognitive ageing approach, collaborative remembering with a partner or spouse may provide cueing and support to benefit older adults’ performance on everyday memory tasks. To combine the value of experimental and cognitive ageing approaches, we tested the effects of collaborative remembering in older, long-married couples who recalled a non-personal word list and a personal semantic list of shared trips. We scored amount recalled as well as the kinds of details remembered. We found evidence for collaborative inhibition across both tasks when scored strictly as number of list items recalled. However, we found collaborative facilitation of specific episodic details on the personal semantic list, details which were not strictly required for the completion of the task. In fact, there was a trade-off between recall of specific episodic details and number of trips recalled during collaboration. We discuss these results in terms of the functions of shared remembering and what constitutes memory success, particularly for intimate groups and for older adults.     

Learning related modulation of functional retrieval networks in man

The medial temporal lobe has been implicated in studies of episodic memory tasks involving spatio-temporal context and object-location conjunctions. We have previously demonstrated that an increased level of practice in a free-recall task parallels a decrease in the functional activity of several brain regions, including the medial temporal lobe, the prefrontal, the anterior cingulate, the anterior insular, and the posterior parietal cortices, that in concert demonstrate a move from elaborate controlled processing towards a higher degree of automaticity. Here we report data from two experiments that extend these initial observations. We used a similar experimental approach but probed for effects of retrieval paradigms and stimulus material. In the first experiment we investigated practice related changes during recognition of object-location conjunctions and in the second during free-recall of pseudo-words. Learning in a neural network is a dynamic consequence of information processing and network plasticity. The present and previous PET results indicate that practice can induce a learning related functional restructuring of information processing. Different adaptive processes likely subserve the functional re-organisation observed. These may in part be related to different demands for attentional and working memory processing. It appears that the role(s) of the prefrontal cortex and the medial temporal lobe in memory retrieval are complex, perhaps reflecting several different interacting processes or cognitive components. We suggest that an integrative interactive perspective on the role of the prefrontal and medial temporal lobe is necessary for an understanding of the processing significance of these regions in learning and memory. It appears necessary to develop elaborated and explicit computational models for prefrontal and medial temporal functions in order to derive detailed empirical predictions, and in combination with an efficient use and development of functional neuroimaging approaches, to further the understanding of the processing significance of these regions in memory.     

Reward prospect interacts with trial-by-trial preparation for potential distraction

When attending for impending visual stimuli, cognitive systems prepare to identify relevant information while ignoring irrelevant, potentially distracting input. Recent work showed that a supramodal distracter-filtering mechanism is invoked in blocked designs involving expectation of possible distracter stimuli, although this entails a cost (distraction-filtering cost) on speeded performance when distracters are expected but not presented. Here we used an arrow-flanker task to study whether an analogous cost, potentially reflecting the recruitment of a specific distraction-filtering mechanism, occurs dynamically when potential distraction is cued trial-to-trial (cued distracter-expectation cost). In order to promote the maximal utilization of cue information by participants, in some experimental conditions the cue also signalled the possibility of earning a monetary reward for fast and accurate performance. This design also allowed us to investigate the interplay between anticipation for distracters and anticipation of reward, which is known to engender attentional preparation. Only in reward contexts did participants show a cued distracter-expectation cost, which was larger with higher reward prospect and when anticipation for both distracters and reward were manipulated trial-to-trial. Thus, these results indicate that reward prospect interacts with the distracter expectation during trial-by-trial preparatory processes for potential distraction. These findings highlight how reward guides cue-driven attentional preparation.     

The free and cued selective reminding test: Validation for mild cognitive impairment and Alzheimer's disease

The International Working Group on Alzheimer's disease (AD) suggested the free and cued selective reminding test (FCSRT) to assess memory, as it showed high sensitivity and specificity in the differentiation of AD from healthy controls and other dementias. The FCSRT involves the use of selective reminding with semantic cueing in memory assessment. This study aims to validate the FCSRT for mild cognitive impairment (MCI) and AD through the analysis of the diagnostic accuracy and the suggestion of cut‐off scores. Patients were classified into two groups according to standard criteria: MCI (n = 100) and AD (n = 70). A matched control group (n = 101) of cognitively healthy subjects was included. The reliability and the validity of the FCSRT were analysed on the immediate (IR) and delayed (DR) recalls. The Cronbach's alpha was 0.915 for the IR and 0.879 for the DR. The total recall measures revealed good areas under the curve for MCI (IR: .818; DR: .828) and excellent for AD (IR: .987; DR: .991). Furthermore, the MCI group was subdivided with respect to a non‐similar/similar AD pattern of impairment, with almost half of the subjects showing an AD‐like decline. This analysis represents a novel contribution regarding the properties of the FCSRT in illustrating the heterogeneity of MCI at baseline. The FCSRT has proved to be a very useful tool in the characterization of the memory impairment of the AD spectrum.     

The Role of Semantic Clustering in Optimal Memory Foraging

Recent studies of semantic memory have investigated two theories of optimal search adopted from the animal foraging literature: Lévy flights and marginal value theorem. Each theory makes different simplifying assumptions and addresses different findings in search behaviors. In this study, an experiment is conducted to test whether clustering in semantic memory may play a role in evidence for both theories. Labeled magnets and a whiteboard were used to elicit spatial representations of semantic knowledge about animals. Category recall sequences from a separate experiment were used to trace search paths over the spatial representations of animal knowledge. Results showed that spatial distances between animal names arranged on the whiteboard were correlated with inter‐response intervals (IRIs) during category recall, and distributions of both dependent measures approximated inverse power laws associated with Lévy flights. In addition, IRIs were relatively shorter when paths first entered animal clusters, and longer when they exited clusters, which is consistent with marginal value theorem. In conclusion, area‐restricted searches over clustered semantic spaces may account for two different patterns of results interpreted as supporting two different theories of optimal memory foraging.     

Putting action memory to the test: testing affects subsequent restudy but not long-term forgetting of action events

Testing memory typically enhances subsequent re-encoding of information (“indirect” testing effect) and, as compared to restudy, it also benefits later long-term retention (“direct” testing effect). We investigated the effect of testing on subsequent restudy and 1-week retention of action events (e.g. “water the plant”). In addition, we investigated if the type of recall practice (noun-cued vs. verb-cued) moderates these testing benefits. The results showed an indirect testing effect that increased following noun-cued recall of verbs as compared to verb-cued recall of nouns. In contrast, a direct testing effect on the forgetting rate of performed actions was not reliably observed, neither for noun- nor verb-cued recall. Thus, to the extent that this study successfully dissociated direct and indirect testing-based enhancements, they seem to be differentially effective for performed actions, and may rely on partially different mechanisms.     

How remembering less acts of gratitude can make one feel more grateful and satisfied with close relationships: The role of ease of recall

Two studies were conducted to examine the influence of ease of recall on state gratitude and satisfaction with close relationships among college students from Mexico. Participants were randomly assigned to remembering and writing down two versus six acts for which they should be grateful. Participants then completed a battery of questionnaires measuring state gratitude, negative affect, satisfaction with close relationships, ease of recall and trait gratitude and extroversion (for Study 2 only). Results from both studies showed that recalling two acts was perceived as easier than recalling six acts. This experience of ease of recall had a positive influence on state gratitude, even after controlling for the effects of trait gratitude and extroversion, which then had positive relationship with satisfaction with close relationships.     

Conflict and metacognitive control: the mismatch-monitoring hypothesis of how others' knowledge states affect recall

Information about others' success in remembering is frequently available. For example, students taking an exam may assess its difficulty by monitoring when others turn in their exams. In two experiments, we investigated how rememberers use this information to guide recall. Participants studied paired associates, some semantically related (and thus easier to retrieve) and some unrelated (and thus harder). During a subsequent cued recall test, participants viewed fictive information about an opponent's accuracy on each item. In Experiment 1, participants responded to each cue once before seeing the opponent's performance and once afterwards. Participants reconsidered their responses least often when the opponent's accuracy matched the item difficulty (easy items the opponent recalled, hard items the opponent forgot) and most often when the opponent's accuracy and the item difficulty mismatched. When participants responded only after seeing the opponent's performance (Experiment 2), the same mismatch conditions that led to reconsideration even produced superior recall. These results suggest that rememberers monitor whether others' knowledge states accord or conflict with their own experience, and that this information shifts how they interrogate their memory and what they recall.