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When using thematically related stimuli with different emotional valences, whether collaboration can bring ongoing and lasting benefits and detriments to episodic memory remains unclear. Aiming to address the issue, the current study innovatively adopted theme-relevant DRM lists with positive, neutral, and negative emotion valences as memory materials. After learning the materials, participants conducted Recall 1 and Recall 2, each containing two sequential memory tasks: the first was the item recall task to recall the studied words and the second was the source retrieval task to recall the colors of the studied words. Participants performed Recall 1 either alone or with a partner, while Recall 2 was conducted individually. Recall 1 confirmed both the detrimental (collaborative inhibition) and beneficial (error pruning and false memory reduction) effects of collaboration for item recall, which manifested the processes of strategy disruption and strategy reversion. Recall 2 reported only benefits, as the post-collaborative recall benefit was recorded in both memory tasks and the false memory reduction appeared in item recall, which provided telling evidence of the mechanisms put forward by the RSDH. In addition, these effects were not sensitive to the emotional valence of DRM lists, which indicated similar strategy disruption and reversion processes between emotional and neutral DRM lists. These results were discussed in terms of the RSDH and other possible accounts. Directions exploring more influential factors in the future and implications are put forward., Author(s): Aiqing Nie [sup.1] [sup.2] [sup.3] , Minye Li [sup.2] , Mengsi Li [sup.2] , Yueyue Xiao [sup.2] , Siyi Wang [sup.2] Author Affiliations: (1) https://ror.org/03zd3ta61, grid.510766.3, 0000 0004 1790 [...]

Previous explorations covering various domains of stereotypes have provided solid evidence that the stereotype-consistent effect, i.e., better memory performance for stereotype-consistent vs. -inconsistent stimuli, emerged exclusively in source memory but not in item memory. Nonetheless, it remains debatable whether this pattern applies to one particular domain, age stereotypes, and to the situation of encountering new objects. To address these issues, the current experiment had 38 undergraduates (18-31 years) study sequential photographs of an elderly or a child performing stereotype-consistent and -inconsistent daily activities. Subsequent memory tests on descriptive phrases adopted the three-key paradigm. Three keys should be pressed respectively to indicate a previously seen action performed by the elderly or the child or new action. Data analyses on the discrimination index of Pr revealed reliable stereotype-inconsistent effect in item memory. Meanwhile, discrepancies arose as the profound stereotype-consistent effect was confirmed in source memory using the conditional source-identification measure (CSIM). For new stimuli, the stereotype-consistent effect also occurred in false alarms as more stereotype-consistent errors were made vs. inconsistent ones. These outcomes indicate that the stereotype-consistent effect occurs among multiple stereotype domains and across memory judgments of both encountered and novel objects considering age stereotypes, strengthening the dual-process model. Implications alerting the potential impairment from stereotypes as well as more research perspectives for future directions are given., Author(s): Minye Li [sup.1] , Aiqing Nie [sup.1] Author Affiliations: (1) grid.13402.34, 0000 0004 1759 700X, Department of Psychology and Behavioral Sciences, Zhejiang University, , 148 Tianmushan Road, 310028, Hangzhou, [...]

Previous studies have confirmed that collaboration in memory can elicit reliable impairment (e.g. collaborative inhibition) and enhancement (e.g. error pruning and post-collaborative recall benefit). However, there is scarce research considering whether these phenomena would occur in semantically related stimuli, especially when in different episodic memory tasks. After encoding some exemplars of certain categories, participants were instructed to sequentially recall originally studied exemplars (item recall) and their encoding colors (source retrieval). The tests were performed twice (Recall 1 and Recall 2), with Recall 1 been done either individually or collaboratively, whereas Recall 2 was an individual test. We replicated the detrimental effect of collaborative inhibition, as well as two beneficial effects of error pruning and post-collaborative recall benefit. Besides, both collaborative inhibition and post-collaborative recall benefit were sensitive to episodic memory tasks; meanwhile, the indicators of both item-specific processing and relational processing were modulated by memory tasks. The novel implications are: (a) revealing that effects of collaborative memory are sensitive to memory tasks; (b) extending the occurrence of a beneficial effect of error pruning to categorized lists; as well as (c) demonstrating that collaboration can attenuate the item-specific processing but enhance the relational processing, and such influences are susceptible to memory tasks. Thus, our findings provide compelling evidence for both the dual-process memory theory and the retrieval strategy disruption hypothesis. Future research is recommended to examine more influential factors., Author(s): Aiqing Nie [sup.1] , Chunchun Ke [sup.1] , Bingyan Guo [sup.1] , Mengsi Li [sup.1] , Yueyue Xiao [sup.1] Author Affiliations: (1) grid.13402.34, 0000 0004 1759 700X, Department of [...]

Two experiments were conducted to explore the animacy advantage in memory, which has shown that words for animate objects are more likely to be remembered than words for inanimate objects. In the first experiment, participants processed words for animate and inanimate objects either shallowly (i.e., by indicating whether each word contained an 'e') or deeply (i.e., by rating the pleasantness of the items). In the second experiment, participants rated the relevance of the study items to either a moving scenario or to a grasslands survival scenario. As expected, in the first experiment the deep processing led to higher rates of recall, and in the second experiment the grasslands survival scenario led to higher rates of recall. In both experiments, animate words were recalled at a significantly higher rate than inanimate words regardless of processing condition. The data from these experiments provide more evidence for the animacy advantage in memory, which supports the adaptive memory view. KEYWORDS: animacy, episodic memory, evolution, levels of processing, survival advantage, Survival Processing Researchers have recently started to focus on the evolutionary roots of memory abilities and have explored the way in which processing items related to one's survival could lead [...]

Research on the nature of episodic memory organization has suggested that the dominant organizing principle among episodic memories is either conceptual organization, where memories cluster around the same content (e.g., memories about the people), or a type of temporal organization known as general events, where memories cluster around extended events (e.g., a holiday in London), repeated events (e.g., Sunday walks in the park), or causally related events (i.e., where one event leads to another). Because these opposing conclusions have been derived separately from involuntary or voluntary measures of autobiographical memory, Mace, Clevinger, and Martin (2010) hypothesized that involuntary retrieval processes and voluntary retrieval processes may be accessing episodic memories differentially, such that one produces high frequencies of conceptually clustered memories, whereas the other produces high frequencies of general event clustered memories. This study failed to find support for this hypothesis. In 2 experiments, 3 different types of voluntary retrieval tasks found that conceptually clustered memories were substantially more frequent than general event clustered memories. We argue that these results support the view that episodic memories are organized mainly conceptually. KEYWORDS: autobiographical memory, autobiographical memory organization, episodic memory, episodic memory organization, Uncovering the associative structure of episodic memories is pivotal to the development of theories about autobiographical memory organization. Although theories of autobiographical memory organization have a long and rich history [...]

The encoding of time and its binding to events are crucial for episodic memory, but how these processes are carried out in hippocampal-entorhinal circuits is unclear. Here we show in freely foraging rats that temporal information is robustly encoded across time scales from seconds to hours within the overall population state of the lateral entorhinal cortex. Similarly pronounced encoding of time was not present in the medial entorhinal cortex or in hippocampal areas CA3-CA1. When animals' experiences were constrained by behavioural tasks to become similar across repeated trials, the encoding of temporal flow across trials was reduced, whereas the encoding of time relative to the start of trials was improved. The findings suggest that populations of lateral entorhinal cortex neurons represent time inherently through the encoding of experience. This representation of episodic time may be integrated with spatial inputs from the medial entorhinal cortex in the hippocampus, allowing the hippocampus to store a unified representation of what, where and when.Temporal information that is useful for episodic memory is encoded across a wide range of timescales in the lateral entorhinal cortex, arising inherently from its representation of ongoing experience., Author(s): Albert Tsao [sup.1] [sup.3] , Jørgen Sugar [sup.1] , Li Lu [sup.1] [sup.4] , Cheng Wang [sup.2] , James J. Knierim [sup.2] , May-Britt Moser [sup.1] , Edvard I. [...]

Although much literature suggests that the age-related decline in episodic memory could be due to difficulties in binding features of information, previous studies focused mainly on memory of paired associations rather than memory of multiple bound features. In reality, however, there are many situations that require binding multiple features together simultaneously. Thus, this three-part experimental study using a working memory task examined two fundamental questions: whether and how well older adults perform a working memory task that requires them to bind three features together (Experiment 1), and whether and how much older adults' memory of units of three bound features could be improved by self-paced encoding and 3 weeks practice (Experiments 2 & 3). The results indicated that although older adults performed as well as young adults in remembering one unit of three features, they showed a deficit in remembering two units, making more severe errors than young adults, and the difference between the two age groups increased when remembering three units. However, older adults improved their memory performance substantially by two means: self-paced encoding and practice. The former primarily shortened reaction times while the latter primarily improved memory accuracy. With self-paced encoding, older adults were also capable of binding at least three units during encoding. Thus, it is possible to assume that under an optimal encoding period, the age-related deficits occur probably not at encoding but at retention and/or retrieval. doi: 10.2190/AG.71.3.b

The ability to remember past experiences (episodic memory) is thought to be related to the ability to imagine possible future experiences (episodic future thinking). Although previous research has established that individuals with autism spectrum disorder (ASD) have diminished episodic memory, episodic future thinking has not previously been investigated within this population. In the present study, high-functioning adults with ASD were compared to closely matched typical adults on a task requiring participants to report a series of events that happened to them in the past and a series of events that might happen to them in the future. For each event described, participants completed two modified Memory Characteristics Questionnaire items to assess self-reported phenomenal qualities associated with remembering and imagining, including self-perspective and degree of autonoetic awareness. Participants also completed letter, category, and ideational fluency tasks. Results indicated that participants with ASD recalled/imagined significantly fewer specific events than did comparison participants and that participants with ASD demonstrated impaired episodic memory and episodic future thinking. In line with this finding, participants with ASD were less likely than comparison participants to report taking a field (first-person) perspective and were more likely to report taking an observer (third-person) perspective during retrieval of past events (but not during simulation of future events), highlighting that they were less likely to mentally reexperience past events from their own point of view. There were no group differences in self-reported levels of autonoetic awareness or fluency task performance. Keywords: autism spectrum disorder, episodic future thinking, episodic memory, perspective, prospection DOI: 10.1037/a0020631

Childhood amnesia refers to the inability of adults to recall events that occurred during their infancy and early childhood. Although it is generally assumed that children and adolescents also experience childhood amnesia, with limited exceptions, most empirical research on the phenomenon has focused exclusively on adults. Here, we developed a new Timeline procedure to directly compare the early memories reported by children, adolescents, and adults. Overall, the proportion of memories reported before the age of 3 years was greater for the children and adolescents relative to the adults. In addition, the single earliest memory reported by children and adolescents was at a younger age than that reported by adults. In fact, the earliest memories reported by the children and adolescents, but not the adults, were significantly younger than the traditional 3 1/2-year-old boundary of childhood amnesia. Regardless of the age of the rememberer, participants' early memories had the same episodic characteristics. We conclude that the boundary and the density of childhood amnesia may increase over the course of human development and that age-related changes in basic memory mechanisms make an important contribution to our understanding of the source of childhood amnesia. Keywords: childhood amnesia, episodic memory, children, adolescents DOI: 10.1037/a0020105

Reports of superior memory for novel relative to familiar material have figured prominently in recent theories of memory. However, such novelty effects are incongruous with long-standing observations that familiar items are remembered better. In 2 experiments, we explored whether this discrepancy was explained by differences in the type of familiarity under consideration or by differences in the difficulty of discriminating targets from lures, which may lead to source confusion for familiar but not novel targets. In Experiment 1, we directly tested whether previously observed novelty effects were the result of novelty, discrimination demands, or both. We used linguistic materials (proverbs) to replicate the novelty effect but found that it occurred only when familiar items were subject to source confusion. In Experiment 2, to examine better how novelty influences episodic memory, we used experimentally familiar, pre-experimentally familiar, and novel proverbs in a paradigm designed to overcome discrimination demand confounds. Memory was better for both types of familiar proverbs. These results indicate that familiarity, not novelty, leads to better episodic memory for studied items, regardless of whether familiarity is experimentally induced or based on prior semantic knowledge. We argue that proposals that state that information is encoded better if it is novel are based on over-generalizations of effects arising from the distinctiveness of novel materials. Keywords: episodic memory, source information, novelty, familiarity, distinctiveness DOI: 10.1037/a0019900

This study assessed metamemory and its role in actual episodic memory performance in 26 patients with obstructive sleep apnea syndrome and 27 healthy controls. Metamemory knowledge and memory beliefs were assessed using the Metamemory Inventory in Adulthood. Episodic memory performance was investigated with the Remember/Know paradigm. Subjective sleepiness was evaluated. Patients underwent a polysomnographic assessment. In contrast to the control group's more stable memory beliefs, patients self-assessed their memory as declining across time, and felt more anxious about their memory. There was only a modest difference between patients' self-perceptions of their memory capacities and those of the control group, but patients' actual memory performance was strongly disturbed. While the latter was significantly correlated with severity of obstructive sleep apnea, scores on the Metamemory Inventory in Adulthood scales were not correlated with physiological measures, subjective sleepiness, or episodic memory performance. Obstructive sleep apnea may affect prefrontal cortex functioning and hence the ability to assess one's own memory impairment. DOI 10.2466/10.13.20.22.PR0.107.4.289-302

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 short-and 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. doi: 10.3758/MC.38.5.659

The capacity to think about specific events that one might encounter in the future--episodic future thought--involves the flexible (re)organization of memory. The present study demonstrates that implicit processes play an important role here. In two experiments (N = 180), participants were asked to generate a personal event that they expected to plausibly occur in the following week. The content of the participants' responses was biased (i.e., primed) by recent thoughts about a specific category of experiences. For instance, participants who had recently been induced to think about social experiences, in the context of an ostensibly unrelated task, were more likely than nonprimed participants to generate similar events occurring in their immediate future. Importantly, the participants were unaware of this unintentional influence of memory. The theoretical and practical implications of these findings for understanding episodic future thought and its relation to memory are discussed. doi: 10.3758/MC.38.5.531

The environmental support hypothesis postulates that it may be possible to reduce older adults' deficits in episodic memory by providing environmental support at the encoding and/or retrieval phases. To examine the validity of this hypothesis, we varied the amount of retrieval support by manipulating data-driven processes. Young and older adults performed a word-stem cued recall task under a low data-driven condition (LDDC) in which the retrieval cue comprised 3 letters, and a higher data-driven condition (HDDC) in which the cue comprised 4 letters. Older adults benefitted more than younger adults from the additional support. Older adults exhibited a large deficit relative to younger adults in the LDDC condition but no age differences were found in the HDDC condition. These findings demonstrate that age-related memory deficits can be reduced by increasing the environmental support at retrieval associated with the data-driven component of retrieval processing. Keywords: episodic memory, aging, environmental support, data-driven processes, conceptually driven processes DOI: 10.1037/a0018570

Recent research on changing fears has examined targeting reconsolidation. During reconsolidation, stored information is rendered labile after being retrieved. Pharmacological manipulations at this stage result in an inability to retrieve the memories at later times, suggesting that they are erased or persistently inhibited. Unfortunately, the use of these pharmacological manipulations in humans can be problematic. Here we introduce a non-invasive technique to target the reconsolidation of fear memories in humans. We provide evidence that old fear memories can be updated with non-fearful information provided during the reconsolidation window. As a consequence, fear responses are no longer expressed, an effect that lasted at least a year and was selective only to reactivated memories without affecting others. These findings demonstrate the adaptive role of reconsolidation as a window of opportunity to rewrite emotional memories, and suggest a non-invasive technique that can be used safely in humans to prevent the return of fear., Learning about potential dangers in the environment is critical for adaptive function, but at times fear learning can be maladaptive, resulting in excessive fear and anxiety. Research on changing fears [...]

Ali organisms capable of long-term memory are necessarily oriented toward the future. We propose that one of the most important adaptive functions of long-term episodic memory is to store information about the past in the service of planning for the personal future. Because a system should have especially efficient performance when engaged in a task that makes maximal use of its evolved machinery, we predicted that future-oriented planning would result in especially good memory relative to other memory tasks. We tested recall performance of a word list, using encoding tasks with different temporal perspectives (e.g., past, future) but a similar context. Consistent with our hypothesis, future-oriented encoding produced superior recall. We discuss these findings in light of their implications for the thesis that memory evolved to enable its possessor to anticipate and respond to future contingencies that cannot be known with certainty. doi:10.3758/MC.38.1.13

There is growing evidence that the brain regions involved in encoding an episode are partially reactivated when that episode is later remembered. That is, the process of remembering an episode involves literally returning to the brain state that was present during that episode. This article reviews studies of episodic and associative memory that provide support for the assertion that encoding regions are reactivated during subsequent retrieval. In the first section, studies are reviewed in which neutral stimuli were associated with different modalities of sensory stimuli or different valences of emotional stimuli. When the neutral stimuli were later used as retrieval cues, relevant sensory and emotion processing regions were reactivated. In the second section, studies are reviewed in which participants used different strategies for encoding stimuli. When the stimuli were later retrieved, regions associated with the different encoding strategies were reactivated. Together, these studies demonstrate not only that the encoding experience determines which regions are activated during subsequent retrieval but also that the same regions are activated during encoding and retrieval. In the final section, relevant questions are posed and discussed regarding the reactivation of encoding regions during retrieval. Keywords: episodic memory, retrieval content, encoding context, strategic encoding, reinstatement DOI: 10.1037/a0017937

In list-method directed forgetting, participants are cued to intentionally forget a previously studied list (List I) before encoding a subsequently presented list (List 2). Compared with remember-cued participants, forget-cued participants typically show impaired recall of List 1 and improved recall of List 2, referred to as List 1 forgetting and List 2 enhancement. In 3 experiments, we examined how amount of postcue encoding influences directed forgetting. Two results emerged dissociating List 1 forgetting from List 2 enhancement. First, an increase in amount of postcue encoding led to an increase in List 1 forgetting but did not affect List 2 enhancement. Second, the forget cue influenced all List 1 items but affected only early List 2 items. A 2-mechanism account of directed forgetting is suggested, according to which List 1 forgetting reflects reduced accessibility of List 1 items, and List 2 enhancement arises from a reset of encoding processes. Keywords: episodic memory, directed forgetting, intentional forgetting, encoding, inhibition DOI: 10.1037/a0017406

The aim of this study was to provide evidence that memory and perceptual processing are underpinned by the same mechanisms. Specifically, the authors conducted 3 experiments that emphasized the sensory aspect of memory traces. They examined their predictions with a short-term priming paradigm based on 2 distinct phases: a learning phase consisting of the association between a geometrical shape and a white noise and a priming phase examining the priming effect of the geometrical shape, seen in the learning phase, on the processing of target tones. In the 3 experiments, the authors found that only the prime associated with the sound in the learning phase had an effect on the target processing. The perceptual nature of the auditory component reactivated by the prime was shown in Experiments 1 and 2 via manipulation of the white noise duration in the learning phase and the stimulus onset asynchrony in the priming phase. Moreover, Experiment 3 highlighted the importance of the simultaneous association of sensory components in the learning phase, which makes it possible to integrate these components in a memory trace. Keywords: memory trace, auditory component, activation, integration

Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral information, the article considers studies assessing the qualitative characteristics of memories, the encoding and remembering of emotional information, and false memories, as well as evidence from populations that show disrupted source memory (older adults, individuals with depression, posttraumatic stress disorder, or schizophrenia). Although there is still substantial work to be done, fMRI is advancing understanding of source memory and highlighting unresolved issues. A continued 2-way interaction between cognitive theory, as illustrated by the source monitoring framework (M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993), and evidence from cognitive neuroimaging studies should clarify conceptualization of cognitive processes (e.g., feature binding, retrieval, monitoring), prior knowledge (e.g., semantics, schemas), and specific features (e.g., perceptual and emotional information) and of how they combine to create true and false memories. Keywords: source memory, prefrontal cortex (PFC), medial temporal lobes (MTL), parietal

The content of episodic memory consists of representations of unique past events. Episodic memories are grounded in a temporal framework (i.e., we remember when an event occurred). It has recently been argued that episodic-like memory in rats is qualitatively different from human episodic memory because, rather than remembering when an earlier past event occurred, rats used the cue of how long ago it occurred. We asked, therefore, whether rats remember the time of day at which they encountered a distinctive event, in addition to what occurred and where it happened. Rats were tested in the morning and afternoon, on separate days. A distinctive flavor (chocolate) was replenished at a daily-unique location at only one of these times. The interval between first and second daily opportunities to eat (study and test, respectively) was constant. Rats adjusted their revisits to the chocolate location at different times of day by using time of day rather than the cue of how long ago an event occurred. Two lines of evidence suggest that rats remembered the time at which the distinctive event occurred. First, under conditions in which the time of test (but not time of study) was novel, rats immediately transferred their knowledge of the chocolate contingency to the new test time. Second, under conditions in which predictions for study and test times were put in conflict, rats again used study time. Our results suggest that, at the time of memory assessment, rats remember when a recent episode occurred, similar to human episodic memory.

Repetition blindness (RB) was investigated in a new paradigm in which effects could stem from items preceding or following a target. Speeded-response tasks in which 3 critical items (C1, C2, and C3) were sequentially presented on each trial. In Experiments 1 and 2, participants were asked to judge whether C2 (the target) was present on each trial. Forward RB was examined in Experiment 1 via manipulation of whether CI and C2 were repeated and backward RB was probed in Experiment 2 via manipulation of whether C2 and C3 were repeated. RB was successfully demonstrated in both experiments: Target presence judgments were slower and less accurate with repeated conditions than with unrepeated conditions. Experiment 3 involved a semantic categorization task in which participants had to judge whether C2 was a letter or a digit. Manipulating forward and backward repetition produced reliable effects on both reaction times and accuracy. The results are consistent with the idea that RB is due to failure in token individualization rather than type refractory problems or failure in memory retrieval. Keywords: repetition blindness, backward repetition blindness, token individuation, temporal attention, episodic memory

Memory for naturalistic events over short delays is important for visual scene processing, reading comprehension, and social interaction. The research presented here examined relations between how an ongoing activity is perceptually segmented into events and how those events are remembered a few seconds later. In several studies, participants watched movie clips that presented objects in the context of goal-directed activities. Five seconds after an object was presented, the clip paused for a recognition test. Performance on the recognition test depended on the occurrence of perceptual event boundaries. Objects that were present when an event boundary occurred were better recognized than other objects, suggesting that event boundaries structure the contents of memory. This effect was strongest when an object's type was tested but was also observed for objects' perceptual features. Memory also depended on whether an event boundary occurred between presentation and test; this variable produced complex interactive effects that suggested that the contents of memory are updated at event boundaries. These data indicate that perceptual event boundaries have immediate consequences for what, when, and how easily information can be remembered. Keywords: event segmentation, short-term memory, episodic memory, perception

We reporta human electrophysiological brain state that predicts successful memory for events before they occur. Using magnetoencephalographic recordings of brain activity during episodic memory encoding, we show that amplitudes of theta oscillations shortly preceding the onsets of words were higher for laterrecalled than for later-forgotten words. Furthermore, single-trial analyses revealed that recall rate in all 24 participants tested increased asa function of increasing prestimulus theta amplitude. This positive correlation was independent of whether participants were preparing for semantic or phonemic stimulus processing, thus likely signifying a memory-related theta state rather than a preparatory task set. Source analysis Iocated this theta state to the medial temporal Iobe, a region known to be critical for encoding and recall. These findings provide insight into state-related aspects of memory formation in humans, and open a perspective for improving memory through theta-related brain states. hippocampus | magnetoencephalography | memory | oscillations| prestimulus

In two experiments, the authors investigate whether switch-cost asymmetries that are often observed in studies of task switching (e.g., Allport, Styles, & Hsieh, 1994) can be best explained by reference to an inhibitory mechanism or episodic memory principles. In Experiment 1, the authors replicated the basic finding, observing the highest switching costs when participants were required to perform an easier perceptual task after having just performed a more difficult conceptual judgment. The reverse task switch produced a significantly smaller switching cost. Experiment 2 revealed that the cost of switching from one difficult conceptual task to another is also higher than the cost of switching from one easy perceptual task to another. In combination, our results demonstrate that the cost of task switching depends mainly on the difficulty of the task participants are required to switch from, favouring an episodic processing account of this switch-cost asymmetry. Keywords: episodic processing, switch-cost asymmetry, task switching, activation/inhibition, switching costs

In 2 experiments we examined the ability of rats to form configural memories of what auditory stimulus (X or Y) was presented where (Context A or B) and when (morning or afternoon). In both experiments, rats received morning presentations of X in Context A and Y in Context B and afternoon presentations of X in B and Y in A. Subsequently, at midday the rats were exposed to trials where X was paired with footshock whereas Y was not. We then assessed the degree of contextual fear in A and B in the morning and the afternoon. In the morning, rats showed more fear in A than in B, and in the afternoon they showed more fear in B than in A. These results indicate that rats can form configural memories that represent what (X or Y) was presented, where (A or B), and when (morning or afternoon). Keywords: Rat; Episodic memory; Mnemonic integration; Configuration.

Three emerging strands of evidence are helping to resolve the causes of the anterograde amnesia associated with damage to the diencephalon. First, new anatomical studies have refined our understanding of the links between diencephalic and temporal brain regions associated with amnesia. These studies direct attention to the limited numbers of routes linking the two regions. Second, neuropsychological studies of patients with colloid cysts confirm the importance of at least one of these routes, the fornix, for episodic memory. By combining these anatomical and neuropsychological data strong evidence emerges for the view that damage to hippocampal--mammillary body--anterior thalamic interactions is sufficient to induce amnesia. A third development is the possibility that the retrosplenial cortex provides an integrating link in this functional system. Furthermore, recent evidence indicates that the retrosplenial cortex may suffer 'covert' pathology (i.e., it is functionally lesioned) following damage to the anterior thalamic nuclei or hippocampus. This shared indirect 'lesion' effect on the retrosplenial cortex not only broadens our concept of the neural basis of amnesia but may also help to explain the many similarities between temporal lobe and diencephalic amnesia. Keywords: Temporal lobe; Fornix; Memory; Subiculum; Entorhinal cortex; Hippocampus; Hypothalamus.

The authors investigated the strategic component (i.e., elaboration and organization of episodic features) and the associative component (i.e., binding processes) of episodic memory and their interactions in 4 age groups (10-12, 13-15, 20-25, and 70-75 years of age). On the basis of behavioral and neural evidence, the authors hypothesized that the two components are functionally related but follow different life-span gradients. In a fully crossed design, age differences in recognition memory for single words versus word pairs (associative demand manipulation) were examined under instructions that emphasized item, pair, or elaborative-pair encoding (strategy manipulation). As predicted, the results showed that the strategic and associative components follow different life-span trajectories. Relative to younger adults, children's difficulties in episodic memory primarily reflected lower levels of strategic functioning. In contrast, older adults showed impairments in both strategic and associative components. The authors conclude that the comparison of strategic and associative components of episodic memory across the life span helps to delineate the two components' unique and interactive contributions to episodic memory performance. Keywords: episodic memory, cognitive control, child development, aging, life-span development

To investigate the neural basis of age-related source memory (SM) deficits, young and older adults were scanned with fMRI while encoding faces, scenes, and face-scene pairs. Successful encoding activity was identified by comparing encoding activity for subsequently remembered versus forgotten items or pairs. Age deficits in successful encoding activity in hippocampal and prefrontal regions were more pronounced for SM (pairs) as compared with item memory (faces and scenes). Age-related reductions were also found in regions specialized in processing faces (fusiform face area) and scenes (parahippocampal place area), but these reductions were similar for item and SM. Functional connectivity between the hippocampus and the rest of the brain was also affected by aging; whereas connections with posterior cortices were weaker in older adults, connections with anterior cortices, including prefrontal regions, were stronger in older adults. Taken together, the results provide a link between SM deficits in older adults and reduced recruitment of hippocampal and prefrontal regions during encoding. The functional connectivity findings are consistent with a posterior-anterior shift with aging previously reported in several cognitive domains and linked to functional compensation. Keywords: fMRI, episodic memory, hippocampus, prefrontal cortex, fusiform face area, parahippocampal place area

Three experiments used directed forgetting (DF) and retrieval practice (RP) to investigate the relation of inhibited items to states of memory awareness occurring at test. In Experiment 1 using list DF robust inhibitory effects were present in cued recall, but in a recognition test these effects were only present in responses accompanied by recollective experience. In Experiments 2 and 3 using RP reliable effects of inhibition were found but these did not relate systematically to states of memory awareness. It is suggested that in DF the to-be-forgotten items are tagged at study as not to be recollectively experienced and so have a specific, inhibitory, relation to states of recollective experience occurring during test. In RP no tagging takes place, and inhibition is automatic or nonintentional and consequently does not have a specific relation to states of memory awareness at test. Keywords: Directed forgetting; Selective practice; Episodic memory; Recollective experience; Retrieval inhibition.

Words having more densely entangled associative structures are more likely to be recalled in the presence of related extralist cues. A context-modified PIER2 model predicts that the implicit activation of such structures during study connects them to the context of the learning episode. In two experiments, we evaluated this assumption by varying the associative density of the study words and the accessibility of context information. In Experiment 1, we varied context accessibility by manipulating context awareness and by delaying testing and filling the delay with different types of interfering tasks. In Experiment 2, we varied accessibility by manipulating test delay and type of interference in a factorial design. The effects of associative density were reduced by using implicit testing that never refers to context, by performing interpolated interference tasks, and finally, by extending the length of the delay. Information that is implicitly activated during an episodic experience is associated to the context of that experience.

Most conceptions of episodic memory hold that reinstatement of encoding operations is essential for retrieval success, but the specific mechanisms of retrieval reinstatement are not well understood. In three experiments, we used saccadic eye movements as a window for examining reinstatement in scene recognition. In Experiment 1, participants viewed complex scenes, while number of study fixations was controlled by using a gaze-contingent paradigm. In Experiment 2, effects of stimulus saliency were minimized by directing participants' eye movemerits during study. At test, participants made remember/know judgments for each recognized stimulus scene. Both experiments showed that remember responses were associated with more consistent study--test fixations than false rejections (Experiments 1 and 2) and know responses (Experiment 2). In Experiment 3, we examined the causal role of gaze consistency on retrieval by manipulating participants' expectations during recognition. After studying name and scene pairs, each test scene was preceded by the same or different name as during study. Participants made more consistent eye movements following a matching, rather than mismatching, scene name. Taken together, these findings suggest that explicit recollection is a function of perceptual reconstruction and that event memory influences gaze control in this active reconstruction process.

Episodic memory for intrinsic item and extrinsic context information is postulated to rely on two distinct types of representation: object and episodic tokens. These provide the basis for familiarity and recollection, respectively. Electrophysiological indices of these processes (ERP old-new effects) were used together with behavioral data to test these assumptions. We manipulated an intrinsic object feature (color; Experiment 1) and a contextual feature (background; Experiments I and 2). In an inclusion task (Experiment 1), the study-test manipulation of color affected object recognition performance and modulated ERP old-new effects associated with both familiarity and recollection. In contrast, a contextual manipulation had no effect, although both intrinsic and extrinsic information was available in a direct feature (source memory) test. When made task relevant (exclusion task; Experiment 2), however, context affected the ERP recollection effect, while still leaving the ERP familiarity effect uninfluenced. We conclude that intrinsic features bound in object tokens are involuntarily processed during object recognition, thus influencing familiarity, whereas context features bound in episodic tokens are voluntarily accessed, exclusively influencing recollection. Figures depicting all the electrodes analyzed are available in an online supplement at www.psychonomic.org/archive.

The present experiments investigated whether the observed associative deficit in older adults' episodic memory is mediated by a reduction of attentional resources. Using a dual-task procedure, younger and older participants studied lists of word pairs either under full attention or while performing a concurrent task. Both experiments showed that dividing attention did not cause a greater impairment to memory for associations than to memory for items in either age group. Furthermore, an analysis of concurrent task performance revealed that older adults' attentional costs for both learning and binding items were not larger than for learning items alone, relative to younger adults. These data provide support for a multicausal interpretation of older adults' memory deficits in which common, depleted attentional resources may be a mechanism that reduces memory for components of an episode in both older and younger adults under divided attention at encoding. In addition, older adults have a unique deficit in memory for the associations between the components, which does not seem to be resource dependent.

The term inhibition of return (IOR) refers to a bias against returning attention to a location or object that has recently been attended. The effect has been shown to occur in various perceptual tasks including stimulus detection, localization, and discrimination, but also to affect higher cognitive processes like lexical access. The present experiments examined whether inhibition of return would impair the high-level processing that is required in accessing item representations in episodic memory. The results show that reaction times for recognition memory decisions are increased under IOR. Furthermore, IOR affects the accuracy of recognition memory, and this effect interacts with the ease of memory access, manipulated, for example, by encoding depth in the learning phase. These results suggest that IOR impairs attentional processing up to the highest cognitive levels, including the access of prior item encounters in episodic memory.

As important as memory is to our daily functions, the ability to extract fundamental features and commonalities from various episodic experiences and to then generalize them into abstract concepts is even more crucial for both humans and animals to adapt to novel and complex situations. Here, we report the neural correlates of the abstract concept of nests or beds in mice. Specifically, we find hippocampal neurons that selectively fire or cease to fire when the mouse perceives nests or beds, regardless of their locations and environments. Parametric analyses show that responses of nest cells remain invariant over changes in the nests' physical shape, style, color, odor, or construction materials; rather, their responses are driven by conscious awareness and physical determination of the categorical features that would functionally define nests. Such functionality-based abstraction and generalization of conceptual knowledge, emerging from episodic experiences, suggests that the hippocampus is an intrinsic part of the hierarchical structure for generating concepts and knowledge in the brain. bed cell | episodic memory | nest cell | semantic memory | hippocampus

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.

Two macaques (Macaca nemestrina) were trained to perform 3 self-directed behaviors on signal and to repeat behaviors after a 'repeat' signal. The cognitive processes underlying the monkeys' repeat performance were evaluated via multiple repetitions of the repeat signal, extended delay periods between target behavior and repeat signal, and by transferring the repeat signal to novel behaviors. The monkeys seemed to use representations of their own past behaviors as a basis for repetition performance, but they mostly failed to correctly repeat target behaviors after extended delays and during transfer tasks. Implications for episodic memory abilities are discussed. Keywords: pigtailed macaques, self-directed behavior, repeat signal, internal stimulus, episodic memory