Automatic activation of episodic information in a semantic memory task

Four experiments are presented in which priming between newly learned associates and priming between well-known associates were examined in lexical decision. All four experiments found priming between newly learned associates, including conditions in which the Stimulus Onset Asynchrony (SOA) between prime and target was short (150 ms) and in which the probability was low (1/12) that the prime and target of a pair would be associated to each other. It was concluded, contrary to suggestions by Carroll and Kirsner (1982) and Tulving (1983), that newly learned associates can prime each other, and that they can do so at short SOAs.     

The role of episodic and semantic memory in episodic foresight

In this paper we describe a special form of future thinking, termed “episodic foresight” and its relation with episodic and semantic memory. We outline the methodologies that have largely been developed in the last five years to assess this capacity in young children and non-human animals. Drawing on Tulving's definition of episodic and semantic memory, we provide a critical analysis of the role that both types of memory might have on the episodic foresight tasks described in the literature. We conclude by highlighting some unanswered questions and suggesting future directions for research that could further our understanding of how memory is intimately connected to episodic foresight.     

Distinguishing the neural correlates of episodic memory encoding and semantic memory retrieval

Episodic memory and semantic memory interact very closely. In particular, episodic memory encoding (EE) tends to elicit semantic memory retrieval (SR), and vice versa. Thus, similar activations for EE and SR in functional neuroimaging studies may reflect shared memory processes, or they may reflect the fact that EE and SR are usually confounded. To address this issue, we used a factorial functional magnetic resonance imaging approach to disentangle the neural correlates of EE and SR. Within the left temporal lobe, the hippocampus was associated with successful EE, whereas a posterior lateral region was associated with successful SR. Within the left inferior prefrontal cortex, a posterior region was involved in SR, a mid region was involved in both SR and EE, and an anterior region was involved in EE, but only when SR was also high. Thus, the neural correlates of EE and SR are dissociable but interact in specific brain regions.     

Psychobiological evidence for the distinction between episodic and semantic memory

The evidence for discrete neurobiological mechanisms that underlie episodic and semantic memory is reviewed. Published data from three separate lines of research are considered: studies of human amnesic patients, psychopharmacological studies of normal human subjects, and studies of working and reference memory in rodents, a distinction that is arguably analogous to the episodic/semantic dichotomy. It is concluded that the available evidence does not indicate that episodic and semantic memory are mediated by discrete neural subsystems. An alternative model of human memory is discussed, based on the concept of parallel distributed processing.An earlier version of this paper was submitted as part of the author's qualifying examination at Emory University.     

Aging and autobiographical memory: dissociating episodic from semantic retrieval

Cognitive aging research documents reduced access to contextually specific episodic details inolder adults, whereas access to semantic or other nonepisodic information is preserved or facilitated. The present study extended this finding to autobiographical memory by using a new measure; the Autobiographical Interview. Younger and older adults recalled events from 5 life periods. Protocols were scored according to a reliable system for categorizing episodic and nonepisodic information. Whereas younger adults were biased toward episodic details reflecting happenings, locations, perceptions, and thoughts, older adults favored semantic details not connected to a particular time and place. This pattern persisted after additional structured probing for contextual details. The Autobiographical Interview is a useful instrument for quantifying episodic and semantic contributions to personal remote memory.     

Bilingualism and reading difficulties: an exploration in episodic and semantic memory

This study was designed to investigate the effect of bilingualism and reading difficulties (RD) on episodic and semantic memory. The subjects included 190 children (aged 9–12 years): 45 Iranian-Swedish bilinguals and 59 Swedish monolinguals with typically developed reading, along with 41 bilinguals and 45 monolinguals with RD. To measure episodic memory, subject-performed and verbal tasks were used for encoding, and both free and cued recall were used for retrieval. Letter and category fluency tasks were used to test semantic memory. In action memory, bilingual children with RD benefited less from enactment encoding form compared to children with typically developed reading. Additionally, bilingual with RD had lower rates of recollection in category fluency compared to their monolingual counterparts. However, in letter fluency, there was not found a difference between performances of bilinguals and monolinguals with RD. We discuss the involvement of long-term memory in both bilingualism and reading.     

The effect of childhood bilingualism on episodic and semantic memory tasks

Kormi-Nouri, Moniri and Nilsson (2003) demonstrated that Swedish-Persian bilingual children recalled at a higher level than Swedish monolingual children, when they were tested using Swedish materials. The present study was designed to examine the bilingual advantage of children who use different languages in their everyday life but have the same cultural background and live in their communities in the same way as monolingual children. In four experiments, 488 monolingual and bilingual children were compared with regard to episodic and semantic memory tasks. In experiments 1 and 2 there were 144 boys and 144 girls in three school groups (aged 9-10 years, 13-14 years and 16-17 years) and in three language groups (Persian monolingual, Turkish-Persian bilingual, and Kurdish-Persian bilingual). In experiments 3 and 4, there were 200 male students in two school groups (aged 9-10 years and 16-17 years) and in two language groups (Persian monolingual and Turkish-Persian bilingual). In the episodic memory task, children learned sentences (experiments 1-3) and words (Experiment 4). Letter and category fluency tests were used as measures of semantic memory. To change cognitive demands in memory tasks, in Experiment 1, the integration of nouns and verbs within sentences was manipulated by the level of association between verb and noun in each sentence. At retrieval, a recognition test was used. In experiments 2 and 3, the organization between sentences was manipulated at encoding in Experiment 2 and at both encoding and retrieval in Experiment 3 through the use of categories among the objects. At retrieval, free recall or cued recall tests were employed. In Experiment 4, the bilingual children were tested with regard to both their first and their second language. In all four experiments, a positive effect of bilingualism was found on episodic and semantic memory tasks; the effect was more pronounced for older than younger children. The bilingual advantage was not affected by changing cognitive demands or by using first/second language in memory tasks. The present findings support the cross-language interactivity hypothesis of bilingual advantage.     

Simulating episodic memory deficits in semantic dementia with the TraceLink model

Although semantic dementia is primarily characterised by deficits in semantic memory, episodic memory is also impaired. Patients show poor recall of old autobiographical and semantic memories, with better retrieval of recent experiences; they can form new memories, and normal performance on pictorial recognition memory has been demonstrated. As these abnormalities in episodic memory are virtually a mirror image of those seen in the amnesic syndromes, semantic dementia poses a challenge to extant models of remote memory and amnesia. Here, we show that one such model, TraceLink, can reproduce some of the principal findings on episodic memory in semantic dementia. A loss of nodes and connections within the trace system, which can be identified with the temporal neocortical memory storage sites implicated in semantic dementia, simulates without further assumptions the findings reported above.     

Simulating episodic memory deficits in semantic dementia with the TraceLink model

Although semantic dementia is primarily characterised by deficits in semantic memory, episodic memory is also impaired. Patients show poor recall of old autobiographical and semantic memories, with better retrieval of recent experiences; they can form new memories, and normal performance on pictorial recognition memory has been demonstrated. As these abnormalities in episodic memory are virtually a mirror image of those seen in the amnesic syndromes, semantic dementia poses a challenge to extant models of remote memory and amnesia. Here, we show that one such model, TraceLink, can reproduce some of the principal findings on episodic memory in semantic dementia. A loss of nodes and connections within the trace system, which can be identified with the temporal neocortical memory storage sites implicated in semantic dementia, simulates without further assumptions the findings reported above.     

The effects of noise and gender on children's episodic and semantic memory

The main objectives in the present study were to examine meaningful irrelevant speech and road traffic noise effects on episodic and semantic memory, and to evaluate whether gender differences in memory performance interact with noise. A total of 96 subjects, aged 13-14 years (n = 16 boys and 16 girls in each of three groups), were randomly assigned to a silent or two noise conditions. Noise effects found were restricted to impairments from meaningful irrelevant speech on recognition and cued recall of a text in episodic memory and of word comprehension in semantic memory. The obtained noise effect suggests that the meaning of the speech were processed semantically by the pupils, which reduced their ability to comprehend a text that also involved processing of meaning. Meaningful irrelevant speech was also assumed to cause a poorer access to the knowledge base in semantic memory. Girls outperformed boys in episodic and semantic memory materials, but these differences did not interact with noise.     

FOK与情节记忆、语义记忆和内隐记忆关系的研究

实验采用R/K判断和PDP测量技术,研究了FOK判断与情节记忆、语义记忆和内隐记忆关系及其监测强度.实验结果表明FOK判断的准确性程度为R判断＞K判断,即对情节记忆监测的准确性要大于对语义记忆监测的准确性.FOK对于自动加工的预测准确性差异不显著,说明FOK监测对内隐记忆的作用是微弱的,由此推测无记忆是意识最高层面的活动.对记忆监测水平强度是由意识--无意识逐渐减弱的.FOK判断对意识性水平较高的记忆活动监测的准确性较强.     

A diffusion model analysis of adult age differences in episodic and semantic long-term memory retrieval

Two experiments investigated adult age differences in episodic and semantic long-term memory tasks, as a test of the hypothesis of specific age-related decline in context memory. Older adults were slower and exhibited lower episodic accuracy than younger adults. Fits of the diffusion model (R. Ratcliff, 1978) revealed age-related increases in non-decisional reaction time for both episodic and semantic retrieval. In Experiment 2, an age difference in boundary separation also indicated an age-related increase in conservative criterion setting. For episodic old-new recognition (Experiment 1) and source memory (Experiment 2), there was an age-related decrease in the quality of decision-driving information (drift rate). As predicted by the context-memory deficit hypothesis, there was no corresponding age-related decline in semantic drift rate.     

Brain activation during episodic memory retrieval: sex differences

Behavioral studies have shown a tendency for women to outperform men on episodic memory tasks. Here, data from a series of positron emission tomography (PET) studies were analyzed to examine sex differences in brain activity associated with episodic memory retrieval (yes/no recognition). A total of 17 women and 17 men were included in the analyses. The strongest effect of the design was a retrieval-related increase in activity, involving right prefrontal and anterior cingulate regions, that was common to women and men. In addition, a significant task-by-sex interaction effect was observed which involved a distributed set of brain regions, including several frontal areas. These results suggest that while the neural correlate of episodic memory retrieval is largely the same for men and women, some differences do exist. Possible explanations for the observed differences are discussed, and it is concluded that biological and experiential factors jointly contribute to sex differences in brain activity.     

The effects of marital status on episodic and semantic memory in healthy middle-aged and old individuals

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on memory, health and aging. The participants were grouped into two age cohorts, 35-60 and 65-85, and studied over a period of 5 years. Episodic memory tasks concerned recognition and recall, whereas semantic memory tasks concerned knowledge and fluency. The results showed, after controlling for education, some diseases, chronological age and leisure activity as covariates, that there were significant differences between married and single individuals in episodic memory, but not in semantic memory. Married people showed significantly better memory performances than singles in both subsystems of episodic memory, that is, recall and recognition. Also, the rate of decline in episodic memory was significantly larger for singles and widowed than other groups over the 5-year time period in both age groups. The findings demonstrate that the positive relation found between marriage and health can be extended to the relation between marriage and cognitive performance. This effect might be explained by the role played by cognitive stimulation in memory and cognition.     

Evidence for similar principles in episodic and semantic memory: The presidential serial position function

When people recall a list of items that they have just experienced (an episodic memory task), the resulting serial position function looks strikingly similar to that observed when people are asked to recall the presidents of the United States (a semantic memory task). Despite the similarity in appearance, there is disagreement about whether the two functions arise from the same processes. A local distinctiveness model of memory, SIMPLE, successfully fit the presidential data using two underlying dimensions: one corresponding to item (or presidential) distinctiveness and the other to order (or positional) distinctiveness. According to the model, presidential primacy and recency are due to the same mechanisms that give rise to primacy and recency effects in both shortand long-term episodic memory. All of these primacy and recency effects reflect the relative distinctiveness principle (Surprenant & Neath, 2009): Items will be well remembered to the extent that they are more distinct than competing items at the time of retrieval.     

Evidence for disproportionate dual-task costs in older adults for episodic but not semantic memory

Previous research demonstrates that older adults are poor at dual tasking, but there is less agreement on whether their decrement is worse than that predicted from single-task performance. This study investigated whether task domain moderates dual-task costs in old age. In two experiments, young and older adults retrieved either previously learned associates (episodic retrieval) or overlearned category members (semantic retrieval) under single or working-memory load conditions, using cued recall (Experiment 1) and recognition (Experiment 2) procedures. In both experiments the proportional costs of dual tasking were age invariant for semantic retrieval but were particularly marked for episodic retrieval, although the size of the age effect was reduced in recognition compared to cued recall. The data suggest that age effects in dual tasking may be domain specific.     

The effects of gender on the retrieval of episodic and semantic components of autobiographical memory

Despite consistent evidence that women exhibit greater episodic memory specificity than men, little attention has been paid to gender differences in the production of episodic details during autobiographical recall under conditions of high and low retrieval support. Similarly the role of gender on the production of semantic details used to support autobiographical memory recollections of specific events has been largely unexplored. In the present study an undergraduate sample of 50 men and 50 women were assessed using the Autobiographical Interview (Levine, Svoboda, Hay, Winocur, & Moscovitch, 2002). Women recalled more episodic information compared to men in the high retrieval support condition, whereas no gender differences were found in the low retrieval support condition. In addition, women produced more repetitions compared to men in the high retrieval support condition. No gender differences were found in the production of semantic details. These results are interpreted in terms of gender differences in encoding and reminiscence practices. This research adds to the literature on gender differences in memory recall and suggests that gender is an important variable in explaining individual differences in AM recall.     

Spreading activation in episodic memory: Further evidence for age independence

Seventy-two young (mean age = 25 years) and 72 old adults (mean age = 71 years) participated in an experiment that addressed the influence of episodic and semantic prime activation on speeded episodic recognition judgements. On each test block, subjects studied two paragraphs at their own pace to achieve a designated level of episodic recognition performance. Following the study period, subjects were presented a series of prime-target trials for speeded episodic recognition. The primes were either (a) episodically related to the target, (b) semantically related to the target, (c) episodically and semantically related to the target, or (d) episodically and semantically unrelated to the target. The stimulus onset asynchrony (SOA) between the primes and targets was either 200 msec, 600 msec, or 1000 msec to address age-related changes in the rate at which these different prime types influenced performance. The results indicated that, compared to young adults, the old adults (a) studied the paragraphs for a longer period of time, (b) responded to the targets more slowly, and (c) were less accurate in their episodic recognition decisions. Although there were these main effects of age, the young and old adults were influenced in a similar fashion by the different prime-target relationships and by the interactive influences of the prime-target relationships and SOA. Correlational analyses indicated that the pattern of priming effects was as similar across the two age groups as across two pseudo-groups that were matched on the age dimension. These results were viewed as further support for the notion that the characteristics of the spreading activation mechanism as reflected by prime-target manipulations are relatively stable across young and old adults.     

The effects of episodic and semantic memory on the identification of sentences masked by white noise

Two studies examine how episodic and semantic memory affect subjects’ abilities to repeat sentences masked by white noise. Subjects first hear a list of 70 sentences that are not masked. Subjects in the framework conditions are told prior to hearing the list that all sentences refer to a contextual framework concerning a deserted island. Subjects in the no-framework groups are not given this information. Subjects in the framework-after condition are given this information only after hearing the list of sentences. Subjects then perform a white-noise identification task. The results indicate that framework subjects are able to identify both old and new framework-related information better than other subjects. Subjects in the no-framework and framework-after conditions identify old information better than control subjects who do not participate in an acquisition phase. Emphasis is placed on the interdependence of episodic and semantic memory, including conditions leading to such interdependence.