从整合的角度看联结记忆中的项目再认

联结记忆由三种成分构成：项目1, 项目2以及项目1-项目2之间的联结, 其中, 对项目1和项目2的再认称之为项目再认, 而对项目1-项目2之间联结的再认称之为联结再认。双加工理论认为项目再认可以由熟悉性和回想加工来完成, 而联结再认只能由回想加工来完成。但近期有大量的研究发现：当要学习的项目对被整合为一个新的整体表征时, 熟悉性也能够支持联结再认。而关于整合对联结记忆中项目再认的研究较少, 总结已有研究提出两种观点：一种是“只有受益”观点(benefits-only)认为整合在增加联结再认的同时不影响项目再认; 另一种是“收支平衡”观点(costs and benefits)认为整合增加联结再认是以牺牲项目再认为代价的。未来研究应该关注整合对联结记忆中项目再认的影响及其神经机制, 了解整合对联结再认和项目再认的具体作用, 有助于针对具体记忆任务选择合适的编码方式来提高记忆表现。     

一体化促进联结记忆的作用机制：熟悉性和回想加工

当两个或两个以上项目进行一体化编码时, 熟悉性也能够支持联结再认, 这一观点已经得到大量研究证据的支持。然而, 关于一体化如何影响联结再认和构成联结的单个项目再认仍存在分歧。通过回顾现有研究发现：(1)一体化一致性是调节一体化与联结再认关系的重要因素; (2)认知资源有限和新/旧词语义相关性是影响一体化对项目再认作用的重要因素; (3)一体化的发生机制存在“项目假说”、“图式假说”以及“精细加工假说”三种可能的理论解释。未来研究不仅需要控制一体化一致性, 还可以比较不同一体化方式的作用大小以及探索一体化效应的毕生发展规律。     

Word frequency influences on the list length effect and associative memory in young and older adults

Many studies show that age deficits in memory are smaller for information supported by pre-experimental experience. Many studies also find dissociations in memory tasks between words that occur with high and low frequencies in language, but the literature is mixed regarding the extent of word frequency effects in normal ageing. We examined whether age deficits in episodic memory could be influenced by manipulations of word frequency. In Experiment 1, young and older adults studied short and long lists of high- and low-frequency words for free recall. The list length effect (the drop in proportion recalled for longer lists) was larger in young compared to older adults and for high- compared to low-frequency words. In Experiment 2, young and older adults completed item and associative recognition memory tests with high- and low-frequency words. Age deficits were greater for associative memory than for item memory, demonstrating an age-related associative deficit. High-frequency words led to better associative memory performance whilst low-frequency words resulted in better item memory performance. In neither experiment was there any evidence for age deficits to be smaller for high- relative to low-frequency words, suggesting that word frequency effects on memory operate independently from effects due to cognitive ageing.     

Proactive interference in working memory is related to adult age and cognitive factors: cross-sectional and longitudinal evidence from the Betula study

ABSTRACT

In working memory (WM), successful maintenance of information is affected by interference. Older adults may be especially susceptible to the effects of interference, which may cause age-related cognitive impairments. A relative score of IC was derived from cross-sectional (n = 869) and longitudinal (n = 443) data to investigate (1) if IC is reduced in normal aging, (2) if individual differences in IC related to individual performance in other cognitive domains, and (3) if 5-year change in IC is related to change in general cognition. Older age was associated with reduced IC, but no decline in IC occurred over 5 years. Also, the ability to control interference in WM was related to performance in episodic memory, verbal fluency, and block design. We also found that IC mediates the relationship between age and cognition, suggesting that age-related cognitive decline is linked to IC. Finally, we demonstrate that change in IC was related to decline in episodic memory.     

Same face,same place,different memory: manner of presentation modulates the associative deficit in older adults

One of the more severe and consequential memory impairments experienced by older adults is the loss of the ability to form and remember associations. Although the associative deficit is often assumed to be unitary, memory episodes may contain different types of associations (e.g., item–item, item–context). Research in younger adults suggests that these different association types may involve different neural mechanisms. This raises the possibility that different association types are not equally affected by aging. In order to investigate this, the current study directly compared memory across item–item and item–context associations in younger and older adults by manipulating the manner of presentation of the associations. Results indicate that the associative deficit in aging is not uniform and that aging has a greater impact on item–context compared to item–item associations. The results have implications for theories of associative memory, age-related cognitive decline, and the functional organization of the medial temporal lobe in aging.     

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.     

Prospective memory across the lifespan: Investigating the contribution of retrospective and prospective processes

Prospective memory performance follows an inverted U-shaped function across the lifespan. Findings on the relative contribution of purely prospective memory and retrospective memory processes within prospective memory to this trajectory are scarce and inconclusive. We analyzed age-related differences in prospective memory performance across the lifespan in a cross-sectional design including six age groups (N = 99, 7–83 years) and investigated possible mechanisms by experimentally disentangling the relative contributions of retrospective memory and purely prospective memory processes. Results confirmed the inverted U-shaped function of prospective memory performance across the lifespan. A significant interaction between process type and age group was observed indicating differential relative contributions of retrospective memory and purely prospective memory processes on the development of prospective memory performance. Our results showed that mainly the pure prospective memory processes within prospective memory lead to lower prospective memory performance in young children and old adults. Moreover, the relative contributions of the retrospective memory and purely prospective memory processes are not uniform at both ends of the lifespan, i.e., in later adulthood the purely prospective memory processes seem to determine performance to an even greater extent than in childhood. Nevertheless, age effects were also observed in the retrospective component which thus contributed to the prospective memory performance differences between the age groups.     

Tests of the DRYAD theory of the age-related deficit in memory for context: not about context, and not about aging

Older adults exhibit a disproportionate deficit in their ability to recover contextual elements or source information about prior encounters with stimuli. A recent theoretical account, DRYAD, attributes this selective deficit to a global decrease in memory fidelity with age, moderated by weak representation of contextual information. The predictions of DRYAD are tested here in three experiments. We show that an age-related deficit obtains for whichever aspect of the stimulus subjects' attention is directed away from during encoding (Experiment 1), suggesting a central role for attention in producing the age-related deficit in context. We also show that an analogous deficit can be elicited within young subjects with a manipulation of study time (Experiment 2), suggesting that any means of reducing memory fidelity yields an interaction of the same form as the age-related effect. Experiment 3 evaluates the critical prediction of DRYAD that endorsement probability in an exclusion task should vary nonmonotonically with memory strength. This prediction was confirmed by assessing the shape of the forgetting function in a continuous exclusion task. The results are consistent with the DRYAD account of aging and memory judgments and do not support the widely held view that aging entails the selective disruption of processes involved in encoding, storing, or retrieving contextual information.     

Investigating the attentional demands of recognition memory: Manipulating depth of encoding at study and level of attention at test

Two experiments investigated the effects of divided attention at test after manipulating levels of processing at study. In Experiment 1 items were studied either intact or as anagrams. In Experiment 2 items were studied with either full or divided attention (DA). In both experiments participants carried out a recognition test with either full or divided attention. Analysis of remember and know responses revealed that DA at test had no effect on remember responses to anagrams or to items studied with full attention. In contrast, Know responses decreased with DA at test, and this occurred for items studied in both deep and shallow encoding conditions. The present study confirms recent findings (Knott & Dewhurst, 2007a) that knowing can rely on more controlled retrieval processes, whereas remembering can rely on more automatic retrieval processes. Differences in the controlled processes associated with recollection and familiarity and remember and know responses are discussed.     

Unrealistic representations of “the self”: A cognitive neuroscience assessment of anosognosia for memory deficit

Three cognitive components may play a crucial role in both memory awareness and in anosognosia for memory deficit (AMD): (1) a personal data base (PDB), i.e., a memory store that contains “semantic” representations about the self, (2) monitoring processes (MPs) and (3) an explicit evaluation system (EES), or comparator, that assesses and binds the representations stored in the PDB with information obtained from the environment.We compared both the behavior and the functional connectivity (as assessed by resting-state fMRI) of AMD patients with aware patients and healthy controls. We found that AMD is associated with an impoverished PDB, while MPs are necessary to successfully update the PDB.AMD was associated with reduced functional connectivity within both the default-mode network and in a network that includes the left lateral temporal cortex, the hippocampus and the insula. The reduced connectivity between the hippocampus and the insular cortex was correlated with AMD severity.     

Priming voluntary autobiographical memories: Implications for the organisation of autobiographical memory and voluntary recall processes

The goal of this study was to show that voluntary autobiographical memories could be primed by the prior activation of autobiographical memories. Three experiments demonstrated voluntary memory priming with three different approaches. In Experiment 1 primed participants were asked to recall memories from their elementary school years. In a subsequent memory task primed participants were asked to recall memories from any time period, and they produced significantly more memories from their elementary school years than unprimed participants. In Experiment 2 primed participants were asked to recall what they were doing when they had heard various news events occurring between 1998 and 2005. Subsequently these participants produced significantly more memories from this time period than unprimed participants. In Experiment 3 primed participants were asked to recall memories from their teenage years. Subsequently these participants were able to recall more memories from ages 13–15 than unprimed participants, where both had only 1 second to produce a memory. We argue that the results support the notion that episodic memories can activate one another and that some of them are organised according to lifetime periods. We further argue that the results have implications for the reminiscence bump and voluntary recall of the past.     

Be aware of the rifle but do not forget the stench: differential effects of fear and disgust on lexical processing and memory

The aim of this study was to investigate the role of discrete emotions in lexical processing and memory, focusing on disgust and fear. We compared neutral words to disgust-related words and fear-related words in three experiments. In Experiments 1 and 2, participants performed a lexical decision task (LDT), and in Experiment 3 an affective categorisation task. These tasks were followed by an unexpected memory task. The results of the LDT experiments showed slower reaction times for both types of negative words with respect to neutral words, plus a higher percentage of errors, this being more consistent for fear-related words (Experiments 1 and 2) than for disgust-related words (Experiment 2). Furthermore, only disgusting words exhibited a higher recall accuracy than neutral words in the memory task. Moreover, the advantage in memory for disgusting words disappeared when participants carried out an affective categorisation task during encoding (Experiment 3), suggesting that the superiority in memory for disgusting words observed in Experiments 1 and 2 could be due to greater elaborative processing. Taken together, these findings point to the relevance of discrete emotions in explaining the effects of the emotional content on lexical processing and memory.     

A study of retrieval processes in action memory for school-aged children: the impact of recall period and difficulty on action memory

ABSTRACT

Research in action memory for adults has shown that enacted encoding is not only retrieved more frequently but is also faster in comparison to verbal encoding. The aim of this study was to investigate retrieval processes in terms of recall period and recall difficulty for different encoding conditions in school-aged children (8-, 10-, 12-, 14-years old). The participants studied verbal tasks, subject-performed tasks and experimenter-performed tasks, and received immediate and final free-recall tests. The results revealed that older children not only outperformed younger children in terms of accuracy but also outpaced them in all recall periods. Moreover, recalls of subject-performed tasks and experimenter-performed tasks were better and faster compared with verbal encoding on both types of recall test, by increasing throughout the recall periods. These results are discussed in terms of memory strategies and information processing methods. Pedagogic implications for the use of action memory in children's learning are also considered.     

Activation and binding in verbal working memory: a dual-process model for the recognition of nonwords

The article presents a mathematical model of short-term recognition based on dual-process models and the three-component theory of working memory [Oberauer, K. (2002). Access to information in working memory: Exploring the focus of attention. Journal of Experimental Psychology: Learning, Memory, and Cognition, 28, 411-421]. Familiarity arises from activated representations in long-term memory, ignoring their relations; recollection retrieves bindings in the capacity-limited component of working memory. In three experiments participants encoded two short lists of nonwords for immediate recognition, one of which was then cued as irrelevant. Probes from the irrelevant list were rejected more slowly than new probes; this was also found with probes recombining letters of irrelevant nonwords, suggesting that familiarity arises from individual letters independent of their relations. When asked to accept probes whose letters were all in the relevant list, regardless of their conjunction, participants accepted probes preserving the original conjunctions faster than recombinations, showing that recollection accessed feature bindings automatically. The model fit the data best when familiarity depended only on matching letters, whereas recollection used binding information.     

Prognostic significance of two sub-categorization methods for the treatment of binge eating disorder: negative affect and overvaluation predict, but do not moderate, specific outcomes

Given the absence of known predictors and moderators for binge eating disorder (BED) treatment outcome and recent findings regarding meaningful sub-categorizations of BED patients, we tested the predictive validity of two subtyping methods. Seventy-five overweight patients with BED who participated in a randomized clinical trial of guided self-help treatments (cognitive-behavioral therapy (CBTgsh) and behavioral weight loss (BWLgsh)) were categorized in two ways. First, a cluster analytic approach yielded dietary-negative affect (29%) and pure dietary (71%) subtypes. Second, research conventions for categorizing patients based upon shape or weight self-evaluation yielded clinical overvaluation (51%) and subclinical overvaluation (49%) subtypes. At the end of treatment, participants subtyped as dietary-negative affect reported more frequent binge episodes compared to the pure dietary subtype, and those with clinical overvaluation reported greater eating disorder psychopathology compared to the subclinical overvaluation group. Neither method predicted binge remission, depressive symptoms, or weight loss. Neither sub-categorization moderated the effects of guided self-help CBT and BWL treatments on any BED outcomes, suggesting that these two specific treatments perform comparably across BED subtypes. In conclusion, dietary-negative affect subtyping and overvaluation subtyping each predicted, but did not moderate, specific and important dimensions of BED treatment outcome.