Measuring recollection and familiarity: Improving the remember/know procedure

The Multiple Dimensions of Familiarity: From Representations to Phenomenology

This article focuses on familiarity, the form of memory allowing humans to recognize stimuli that have been encountered before. We aim to emphasize its complex nature which includes representational and phenomenological dimensions. The former implies that its neural correlates depend on the type and complexity of the cue stimulus, as different classes of stimuli are represented in distributed ventral visual and medial temporal regions. The second dimension relates to the subjective feeling of familiarity, which results from a fluency signal that is attributed to past encounters with the stimulus. We review mnemonic and non-mnemonic sources of fluency that can induce a sense of familiarity, as well as cases where fluency is not attributed to memory, among which the phenomenological experience of déjà-vu. Across these two dimensions, we highlight key questions to be answered by future studies to improve our understanding of the underpinnings of this form of memory and contribute to building an integrative neurocognitive model of familiarity. Essential to this aim is the clarification of the computational, cognitive, and neural mechanisms involved, namely global matching, fluency attribution, and sharpening. Furthermore, future research is needed to unravel the relationships between these mechanisms. We argue that to achieve these goals, researchers must use appropriate behavioral paradigms and clearly define which dimension of familiarity they investigate.

What is autonoetic consciousness? Examining what underlies subjective experience in memory and future thinking

Autonoetic consciousness is the awareness that an event we remember is one that we ourselves experienced. It is a defining feature of our subjective experience of remembering and imagining future events. Given its subjective nature, there is ongoing debate about how to measure it. Our goal was to develop a framework to identify cognitive markers of autonoetic consciousness. Across two studies (N = 342) we asked young, healthy participants to provide written descriptions of two autobiographical memories, two plausible future events, and an experimentally encoded video. Participants then rated their subjective experience during remembering and imagining. Exploratory Factor Analysis of this data uncovered the latent variables underlying autonoetic consciousness across these different events. In contrast to work that emphasizes the distinction between Remember and Know as being key to autonoetic consciousness, Re-experiencing, and Pre-experiencing for future events, were consistently identified as core markers of autonoetic consciousness. This was alongside Mental Time Travel in all types of memory events, but not for imagining the future. In addition, our factor analysis allows us to demonstrate directly - for the first time - the features of mental imagery associated with the sense of autonoetic consciousness in autobiographical memory; vivid, visual imagery from a first-person perspective. Finally, with regression analysis, the emergent factor structure of autonoetic consciousness was able to predict the richness of autobiographical memory texts, but not of episodic recall of the encoded video. This work provides a novel way to assess autonoetic consciousness, illustrates how autonoetic consciousness manifests differently in memory and imagination and defines the mental representations intrinsic to this process.

Forgetting rate for the familiarity and recollection components of recognition in amnestic mild cognitive impairment: A longitudinal study

Here we aimed to investigate the rate of forgetting of the familiarity and recollection components of recognition in patients at the onset of medial temporal lobe (MTL) pathology and destined to convert to Alzheimer's disease (AD). For this purpose, we conducted a longitudinal study of 13 patients who were diagnosed with amnestic mild cognitive impairment (a-MCI) at the first assessment and followed-up for 3 years. During this time, five patients converted to AD and eight remained in a stable condition of cognitive impairment. A group of 15 healthy subjects were enrolled as the control group (HC). In order to separately quantify the contribution of recollection and familiarity to recognition memory performance, the experimental sample was submitted to a modified version of Huppert and Piercy's procedure that included a Remember/Know paradigm. Data demonstrated that both stable and converter a-MCI patients forgot memory traces relative to the familiarity components of recognition at the same rate as HC. Conversely, converter a-MCI patients showed accelerated long-term forgetting specifically for the recollection component of recognition compared to stable a-MCI and HC. This is the first empirical demonstration that familiarity and recollection components of declarative memory are subject to different rates of forgetting in a-MCI patients as a function of their longitudinal clinical outcome. Our finding of accelerated long-term forgetting of the recollection component of recognition disclosed by converter a-MCI patients suggests that atrophy in the MTL not only interferes with the storage aspects but also disrupts the consolidation of memory traces.

Context reinstatement requires a schema relevant virtual environment to benefit object recall

How does our environment impact what we will later remember? Early work in real-world environments suggested that having matching encoding/retrieval contexts improves memory. However, some laboratory-based studies have not replicated this advantageous context-dependent memory effect. Using virtual reality methods, we find support for context-dependent memory effects and examine an influence of memory schema and dynamic environments. Participants (N = 240) remembered more objects when in the same virtual environment (context) as during encoding. This traded-off with falsely "recognizing" more similar lures. Experimentally manipulating the virtual objects and environments revealed that a congruent object/environment schema aids recall (but not recognition), though a dynamic background does not. These findings further our understanding of when and how context affects our memory through a naturalistic approach to studying such effects.

The Impact of Episodic Memory on Decision-Making in Aging: Scenarios from Everyday Life Situations

Background: Decision-making is a highly complex process that depends on numerous cognitive functions, such as episodic memory. It is also influenced by aging. However, how changes in episodic memory with age contribute to changes in decision-making is not clear yet. Objective: This work aimed to examine the role of two memory processes, recollection and familiarity, in decision-making in ageing. Method: Thirty young adults and 30 older adults performed two episodic memory tasks: recognition, which allowed for the measurement of recollection and familiarity, and recall, which allowed for the measurement of recollection. In both tasks, they first viewed a series of pictures and then were asked to recognise or recall them respectively. They also performed an original scenario task based on situations inspired by everyday life, evaluating decision-making under conditions of either risk or ambiguity. In this task, participants were presented with short descriptions of situations requiring a decision and had to choose between two given options. Results: Lower performances was observed in recall and recognition tasks in older than in young adults. In the scenarios task, young adults sought significantly more risk and ambiguity than older adults. In both young and older adults, recollection and familiarity processes were involved differently in decision-making. The former is more involved in decision-making under ambiguity, and the latter in decision-making under risk. Conclusions: The results suggest that decision-making changes with age, but that the involvement of the episodic memory, familiarity and recollection processes, does not appear to vary with age.

The hippocampus supports the representation of abstract concepts: Implications for the study of recognition memory

Words, unlike images, are symbolic representations. The associative details inherent within a word's meaning and the visual imagery it generates, are inextricably connected to the way words are processed and represented. It is well recognised that the hippocampus associatively binds components of a memory to form a lasting representation, and here we show that the hippocampus is especially sensitive to abstract word processing. Using fMRI during recognition, we found that the increased abstractness of words produced increased hippocampal activation regardless of memory outcome. Interestingly, word recollection produced hippocampal activation regardless of word content, while the parahippocampal cortex was sensitive to concreteness of word representations, regardless of memory outcome. We reason that the hippocampus has assumed a critical role in the representation of uncontextualized abstract word meaning, as its information-binding ability allows the retrieval of the semantic and visual associates that, when bound together, generate the abstract concept represented by word symbols. These insights have implications for research on word representation, memory, and hippocampal function, perhaps shedding light on how the human brain has adapted to encode and represent abstract concepts.

Normative data of the Italian Famous Face Test

The faces we see in daily life exist on a continuum of familiarity, ranging from personally familiar to famous to unfamiliar faces. Thus, when assessing face recognition abilities, adequate evaluation measures should be employed to discriminate between each of these processes and their relative impairments. We here developed the Italian Famous Face Test (IT-FFT), a novel assessment tool for famous face recognition in typical and clinical populations. Normative data on a large sample (N = 436) of Italian individuals were collected, assessing both familiarity (d') and recognition accuracy. Furthermore, this study explored whether individuals possess insights into their overall face recognition skills by correlating the Prosopagnosia Index-20 (PI-20) with the IT-FFT; a negative correlation between these measures suggests that people have a moderate insight into their face recognition skills. Overall, our study provides the first online-based Italian test for famous faces (IT-FFT), a test that could be used alongside other standard tests of face recognition because it complements them by evaluating real-world face familiarity, providing a more comprehensive assessment of face recognition abilities. Testing different aspects of face recognition is crucial for understanding both typical and atypical face recognition.

Neural correlates of retrospective memory confidence during face-name associative learning

The ability to accurately assess one's own memory performance during learning is essential for adaptive behavior, but the brain mechanisms underlying this metamemory function are not well understood. We investigated the neural correlates of memory accuracy and retrospective memory confidence in a face-name associative learning task using magnetoencephalography in healthy young adults (n = 32). We found that high retrospective confidence was associated with stronger occipital event-related fields during encoding and widespread event-related fields during retrieval compared to low confidence. On the other hand, memory accuracy was linked to medial temporal activities during both encoding and retrieval, but only in low-confidence trials. A decrease in oscillatory power at alpha/beta bands in the parietal regions during retrieval was associated with higher memory confidence. In addition, representational similarity analysis at the single-trial level revealed distributed but differentiable neural activities associated with memory accuracy and confidence during both encoding and retrieval. In summary, our study unveiled distinct neural activity patterns related to memory confidence and accuracy during associative learning and underscored the crucial role of parietal regions in metamemory.

A conditional judgment procedure for probing evaluative conditioning effects in the absence of feelings of remembering

Attitude research has capitalized on evaluative conditioning procedures to gain insight into how evaluations are formed and may be changed. In evaluative conditioning, a conditioned stimulus (CS; e.g., an unfamiliar soda brand) is paired with an unconditioned stimulus (US) of affective value (e.g., a pleasant picture). Following this pairing, a change in CS liking may be observed (e.g., the soda brand is liked better). A question with far-reaching theoretical and practical implications is whether the change in CS liking is found when participants feel they do not remember the CS-US pairings at the time an evaluation is produced about the CS. Here, we introduce a new conditional judgment procedure-the two-button-sets (TBS) task-for probing evaluative conditioning effects without feelings of remembering about the valence of the US paired with the CS. In three experiments, the TBS is (1) is successfully validated; it is also used to (2) provide preliminary information on the feeling of remembering question, and (3) to examine an affect-consistent bias in memory judgments for CS-US pairings. Results do not support evaluative effects in the absence of feelings of remembering, and they oppose the view that affect-consistent bias is limited to memory uncertainty. We discuss these findings in light of previous evidence and of dual-learning models of attitudes. We also discuss limitations and research avenues related to the new procedure.

A meta-analysis of event-related potential correlates of recognition memory

A longstanding question in memory research is whether recognition is supported by more than one mnemonic process. Dual-process models distinguish recollection of episodic detail from familiarity, while single-process models explain recognition in terms of one process that varies in strength. Dual process models have drawn support from findings that recollection and familiarity elicit distinct electroencephalographic event-related potentials (ERPs): a mid-frontal ERP effect that occurs at around 300-500 ms post-stimulus onset and is often larger for familiarity than recollection contrasts, and a parietal ERP effect that occurs at around 500-800 ms and is larger for recollection than familiarity contrasts. We sought to adjudicate between dual- and single-process models by investigating whether the dissociation between these two ERP effects is reliable over studies. We extracted effect sizes from 41 experiments that had used Remember-Know, source memory, and associative memory paradigms (1,000 participants). Meta-analysis revealed a strong interaction between ERP effect and mnemonic process of the form predicted by dual-process models. Although neither ERP effect was significantly process-selective taken alone, a moderator analysis revealed a larger mid-frontal effect for familiarity than recollection contrasts in studies using the Remember-Know paradigm. Mega-analysis of raw data from six studies further showed significant process-selectivity for both mid-frontal and parietal ERPs in the predicted time windows. On balance, the findings favor dual- over single-process theories of recognition memory, but point to a need to promote sharing of raw data.

Psychometric and next day electrodermal activity data from an experiment involving midazolam, ketamine, and painful stimulation

This is a report of unpublished data obtained from a randomized, single-blind, within-subject crossover design, neuroimaging trial comparing the effects of midazolam and ketamine on memory and pain. An experimental auditory paradigm paired with the periodic pain was used to examine auditory encoding and subsequent recognition. Psychometric surveys assessed stress, anxiety, depression, and pain behaviors. These data were collected to potentially characterize inter-subject variation during analysis. Electrodermal activity was measured to examine the association between previous pain-pairing of experimental items and autonomic responses during next day recognition memory testing, with exposure to the same auditory word items. Electrodermal responses were determined using an event-related analysis approach. These data may help shape future experiments using psychometric data to characterize individual responses or using next day electrodermal activity to determine conditioned responses to previously-experienced aversive stimuli.

Phonological similarity between words is represented in declarative memory as spatial distance

Space can be used as a metaphor to describe semantic and perceptual similarity. Research has shown that similarity and spatial information can influence each other. On the one hand, similarity entails spatial closeness; on the other hand, proximity leads to similarity judgment. This spatial information can be stored in declarative memory and measured later on. However, it is unknown if phonological similarity/dissimilarity between words is represented as spatial closeness/distance in declarative memory. In this study, 61 young adults were tested on a remember-know (RK) spatial distance task. Participants learned noun pairs on the PC screen that were manipulated concerning their phonological similarity (similar vs. dissimilar) and reciprocal spatial distance (near vs. far). In the recognition phase, old-new, RK, and spatial distance judgments were asked. We found that for hit responses in both R and K judgments, phonologically similar word pairs were remembered closer compared to phonologically dissimilar pairs. This was also true for false alarms after K judgments. Lastly, the actual spatial distance at encoding was only retained for hit R responses. Results suggest that phonological similarity/dissimilarity is represented respectively with spatial closeness/distance and that this information is stored in the neurocognitive system of declarative memory.

Pupil response patterns distinguish true from false memories

Memory is reconstructive and error-prone, which make memory illusions very common in everyday life. However, studying memory illusions can provide valuable insights into how memory works. Pupil response has emerged, in recent years, as an indicator of memory encoding and retrieval, however its validity as a measure of memory success is debated. In this study, we explored whether pupil response patterns can differentiate true from false memories and whether variations in the temporal dynamics of pupil response can elucidate the mechanisms underlying false memory creation. The Deese-Roediger-McDermott (DRM) paradigm was employed to generate false memories in two separate experiments involving visual and auditory stimuli. Pupil responses effectively differentiated true from false memories based on variations in pupil amplitude at different temporal components. This discrimination remained consistent across both experiments, with slightly stronger effects in the auditory condition, aligning with the more pronounced false memory effects in this condition. Notably, differential pupil responses between true and false memories varied based on the type of memory involved at recognition. These findings provide valuable insights into the cognitive processes underlying memory distortions, with implications for theoretical frameworks and real-world contexts.

My child and I: self- and child-reference effects among parents with self-worth contingent on children's performance

Research shows that parents' self-worth may be contingent on their children's performance, with implications for their interactions with children. This study examined whether such child-based worth is manifested in parents' recognition memory. Parents of school-age children in China (N = 527) reported on their child-based worth and completed a recognition memory task involving evaluative trait adjectives encoded in three conditions: self-reference, child-reference, and semantic processing. The more parents had child-based worth, the more they exhibited a child-reference effect - superior recognition memory of evaluative trait adjectives encoded with reference to the child rather than semantically. Parents exhibited the classic self-reference effect in comparisons of recognition memory between the self-reference and semantic processing conditions, but this effect was not evidenced among parents high in child-based worth. Only parents low in child-based worth exhibited the self-reference effect in comparisons between the self-reference and child-reference conditions. Findings suggest that when parents hinge their self-worth on children's performance, evaluative information related to children may be an elaborate structure in memory.

Recognition, remember-know, and confidence judgments: no evidence of cross-contamination here!

ABSTRACTWe report three experiments designed to reveal the mechanisms that underlie subjective experiences of recognition by examining effects of how those experiences are measured. Prior research has explored the potential influences of collecting metacognitive measures on memory performance. Building on this work, here we systematically evaluated whether cross-measure contamination occurs when remember-know (RK) and/or confidence (C) judgments are made after old/new recognition decisions. In Experiment 1, making either RK or C judgments did not significantly influence recognition relative to a standard no-judgment condition. In Experiment 2, making RK judgments in addition to C judgments did not significantly affect recognition or confidence. In Experiment 3, making C judgments in addition to RK judgments did not significantly affect recognition or patterns of RK responses. Cross-contamination was not apparent regardless of whether items were studied using a shallow or deep levels-of-processing task - a manipulation that yielded robust effects on recognition, RK judgments, and C. Our results indicate that under some conditions, participants can independently evaluate their recognition, subjective recognition experience, and confidence. Though contamination across measures of metamemory and memory is always possible, it may not be inevitable. This has implications for the mechanisms that underlie subjective experiences that accompany recognition judgments.

EEG-based univariate and multivariate analyses reveal that multiple processes contribute to the production effect in recognition

The production effect (PE) is the finding that reading words aloud rather than silently during study leads to improved memory. We used electroencephalography (EEG) techniques to detect the contributions of recollection, familiarity, and attentional processes to the PE in recognition memory, using Chinese stimuli. During the study phase, participants encoded each list item aloud, silently, or by performing a non-unique aloud (control) task. During the test phase, they made remember/know/new recognition judgments. We recorded EEG data in both phases. The behavioral results replicated the typical pattern with English stimuli: Recognition was better in the aloud condition than in the silent (and control) condition, and this PE was due to enhanced recollection and familiarity. At study, the amplitude of the P3b ERP component was greater in the aloud than in the silent/control conditions, suggesting that reading aloud increases attention or preparatory processing during the intention phase. At test, the recollection-based LPC old/new effect was largest in the aloud condition; however, the familiarity-based FN400 old/new effect was equivalent between the aloud condition and the silent/control conditions. Only the LPC effect correlated with the behavioral effect. Moreover, multivariate pattern analysis (MVPA) showed that accurate classification of items as 'aloud' versus 'new' mainly occurred in the later period of the recognition response, consistent with the LPC old/new effect. Our findings suggest that the within-subject PE in recognition memory reflects enhanced attention and distinctiveness, rather than increased memory strength. More broadly, our findings suggest that encoding strategies such as production enhance recollection more than familiarity.

Lay Definitions of Intelligence, Knowledge, and Memory: Inter- and Independence of Constructs

The present study examined how lay participants define the following concepts used widely in psychology: being intelligent, knowing, and remembering. In the scientific community, knowledge overlaps with the contents of semantic memory, crystallized intelligence reflects the accumulation of knowledge, knowledge and event memory interact, and fluid intelligence and working memory correlate. Naturally, the lay public has implicit theories of these constructs. These theories mainly distinguish between intelligent and unintelligent behaviors and tend to include characteristics outside psychometric studies of intelligence, such as emotional intelligence. Here, we asked lay participants from the online platform Prolific to explain "what does being intelligent mean to you?" as well as "knowing" and "remembering" to understand their degree of alignment with theoretical conceptualizations in the research community. Qualitative coding of participant definitions showed that intelligence and knowledge are closely related, but asymmetrically-when defining what it means to be intelligent, participants reference knowledge, but intelligence is not considered in explaining knowing. Although participants note that intelligence is multi-faceted and related to problem-solving, there is an emphasis (in terms of frequency of mentions) on the crystallized side of intelligence (i.e., knowledge). A deeper understanding of lay participants' mental models of these constructs (i.e., their metacognitions) is essential for bridging gaps between experts and the general public.

The binding structure of event elements in episodic memory and the role of animacy

Experienced events consist of several elements which need to be bound together in memory to represent the event in a coherent manner. Given such bindings, the retrieval of one event element should be related to the successful retrieval of another element of the same event, thus leading to a stochastic dependency of the retrieval of event elements. The way in which bindings are structured is not yet clearly established and only few moderators of the binding of event elements have been identified. We present results from three experiments aiming to distinguish between an integrated binding structure, in which event elements are bound into a unitary representation, and a hierarchical binding structure, in which event elements are preferentially bound to specific types of elements. Experiments 2 and 3 were additionally designed to identify animacy, an entity's property of being alive, as a potential moderator of the binding of event elements. We also offer a new approach for modelling dependencies of the retrieval of event elements which mitigates some limitations of previous approaches. Consistent with previous literature, we found dependencies of the retrieval of event elements if all of an event's constituent associations were shown. We found mixed evidence for integrated or hierarchical binding structures but found dependency of the retrieval of event elements to be sensitive to the presence of animacy in an event. The results suggest that binding structures may vary depending on moderators such as animacy or event structure awareness. Theoretical implications and directions for future research are discussed.

Learning facilitates dual-process face recognition regardless of holistic processing

Much evidence suggests that faces are recognized based on their global familiarity in a signal-detection manner. However, experiments drawing this conclusion typically present study lists of faces only once or twice, and the nature of face recognition at higher levels of learning remains unclear. Here, three experiments are reported in which participants studied some faces eight times and others twice and then took a recognition test containing previously viewed faces, entirely new faces, and faces which recombined the parts of previously viewed faces. Three measures converged to suggest that study list repetition increased the likelihood of participants rejecting recombined faces as new by recollecting that their parts were studied but in a different combination, and that manipulating holistic or Gestalt-like processing-a hallmark of face perception-qualitatively preserved its effect on how memory judgments are made. This suggests that face learning causes a shift from the use of a signal-detection strategy to the use of a dual-process strategy of face recognition regardless of holistic processing.

The P3 indexes the distance between perceived and target image

Visual recognition requires inferring the similarity between a perceived object and a mental target. However, a measure of similarity is difficult to determine when it comes to complex stimuli such as faces. Indeed, people may notice someone "looks like" a familiar face, but find it hard to describe on the basis of what features such a comparison is based. Previous work shows that the number of similar visual elements between a face pictogram and a memorized target correlates with the P300 amplitude in the visual evoked potential. Here, we redefine similarity as the distance inferred from a latent space learned using a state-of-the-art generative adversarial neural network (GAN). A rapid serial visual presentation experiment was conducted with oddball images generated at varying distances from the target to determine how P300 amplitude related to GAN-derived distances. The results showed that distance-to-target was monotonically related to the P300, showing perceptual identification was associated with smooth, drifting image similarity. Furthermore, regression modeling indicated that while the P3a and P3b sub-components had distinct responses in location, time, and amplitude, they were similarly related to target distance. The work demonstrates that the P300 indexes the distance between perceived and target image in smooth, natural, and complex visual stimuli and shows that GANs present a novel modeling methodology for studying the relationships between stimuli, perception, and recognition.

Temporal and contextual binding in episodic memory in younger and older adults

Episodic memory (EM) is a subsystem responsible for storing and recalling information about the basic elements of an event in a binding manner. Some approaches consider the temporal element to be one of the basic components of EM (WWWhen paradigm), while others consider that the contextual component is able in practice to better represent this cognitive ability (WWWhich paradigm). The relationship of both paradigms simultaneously with other instruments for measuring EM has not been investigated in healthy older adults. Thus, the present study examined the performance of young and older adults on questions based on the WWWhen and WWWhich paradigms, investigating the relationship of these questions with episodic (Remember) and non-episodic (Know) strategies. The results showed that for the younger adults both the questions demonstrated to only be significantly related with the "remember" strategy. On the other hand, older adults presented a response pattern in which the "WWWhich" questions used only episodic strategies for their correct resolution. Aging appears to promote a substantial reduction in both "Remember" and "Know" strategies, mainly those associated with solving tasks based on the temporal element of EM.

Ecological validity of don't remember and don't know for distinguishing accessibility- versus availability-based retrieval failures in older and younger adults: knowledge for news events

With pursuit of incremental progress and generalizability of findings in mind, we examined a possible boundary for older and younger adults' metacognitive distinction between what is not stored in memory versus merely inaccessible with materials that are not process pure to knowledge or events: information regarding news events. Participants were asked questions about public events such as celebrity news, tragedies, and political events that were widely experienced in the previous 10-12 years, responding "I don't know" (DK) or "I don't remember" (DR) when retrieval failed. Memories of these events are relatively recently acquired in rich, naturalistic contexts and are likely not fully separated from episodic details. When retrieval failed, DR items were recognized with higher accuracy than DK items, both immediately and 2 years later, confirming that self-reported not remembering reflects failures of accessibility, whereas not knowing better captures a lack of availability. In fact, older adults distinguished between the causes of retrieval failures more precisely than younger adults. Together, these findings advance the reliability, validity, and generalizability of using DR and DK as a metacognitive tool to address the phenomenological experience and behavioral consequences of retrieval failures of information that contains both semantic and episodic features. Implications for metacognition in aging and related constructs like familiarity, remembering, and knowing are discussed.

Hippocampal activity during memory and visual perception: The role of representational content

The functional organisation of the medial temporal lobe (MTL) has long been described on the basis of cognitive processes such as recollection or familiarity. However, this view has recently been challenged, and researchers have proposed decomposing cognitive phenomena into representations and operations. According to the representational view, representations, such as scenes for the hippocampus and objects for the perirhinal cortex, are critical in understanding the role of MTL regions in cognition. In the present study, 51 healthy young participants underwent functional magnetic resonance imaging (fMRI) while completing a visual-discrimination task. Subsequently, half of the participants performed a patch-cue recognition procedure in which "Rec" responses are believed to reflect the operation of pattern completion, whereas the other half performed a whole-item remember/know procedure. We replicated the previously-reported demonstration that hippocampal involvement in pattern completion is preferential for scenes as compared with objects. In contrast, the perirhinal cortex was more recruited for object processing than for scene processing. We further extended these results to the operations of strength-signal memory and visual discrimination. Finally, the modulation of hippocampal engagement in pattern completion by representational content was found to be specific to its anterior segment. This observation is consistent with the proposal that this segment would process broad/global representations, whereas the posterior hippocampus would perform sharp/local representations. Taken together, these results favour the representational view of MTL functional organisation, but support that this specialisation differs along the hippocampal long-axis.

Neutral auditory words immediately followed by painful electric shock may show reduced next-day recollection

In this study, we investigated the effect of experimentally delivered acute pain on memory. Twenty-five participants participated in experimental sessions on consecutive days. The first session involved a categorization task to encourage memory encoding. There were two conditions, presented in randomized order, in which participants listened to a series of words, which were repeated three times. In one condition, one-third of the word items were immediately followed by a painful electrical shock. This word-shock pairing was consistent across repetition and the pain-paired items were presented unpredictably. In the other condition, all word items were not associated with pain. Response times over these repeated presentations were assessed for differences. Explicit memory was tested the following day, employing a Remember-Know assessment of word recognition, with no shocks employed. We found evidence that recollection may be reduced for pain-paired words, as the proportion of correct Remember responses (out of total correct responses) was significantly lower. There were no significant reductions in memory for non-pain items that followed painful stimulation after a period of several seconds. Consistent with the experience of pain consuming working memory resources, we theorize that painful shocks interrupt memory encoding for the immediately preceding experimental items, due to a shift in attention away from the word item.

The extent and specificity of visual exploration determines the formation of recollected memories in complex scenes

Our visual memories of complex scenes often appear as robust, detailed records of the past. Several studies have demonstrated that active exploration with eye movements improves recognition memory for scenes, but it is unclear whether this improvement is due to stronger feelings of familiarity or more detailed recollection. We related the extent and specificity of fixation patterns at encoding and retrieval to different recognition decisions in an incidental memory paradigm. After incidental encoding of 240 real-world scene photographs, participants (N = 44) answered a surprise memory test by reporting whether an image was new, remembered (indicating recollection), or just known to be old (indicating familiarity). To assess the specificity of their visual memories, we devised a novel report procedure in which participants selected the scene region that they specifically recollected, that appeared most familiar, or that was particularly new to them. At encoding, when considering the entire scene,subsequently recollected compared to familiar or forgotten scenes showed a larger number of fixations that were more broadly distributed, suggesting that more extensive visual exploration determines stronger and more detailed memories. However, when considering only the memory-relevant image areas, fixations were more dense and more clustered for subsequently recollected compared to subsequently familiar scenes. At retrieval, the extent of visual exploration was more restricted for recollected compared to new or forgotten scenes, with a smaller number of fixations. Importantly, fixation density and clustering was greater in memory-relevant areas for recollected versus familiar or falsely recognized images. Our findings suggest that more extensive visual exploration across the entire scene, with a subset of more focal and dense fixations in specific image areas, leads to increased potential for recollecting specific image aspects.

The dissociating of reward feedback on familiarity and recollection processing: evidence from event-related potential

OBJECTIVES

Although previous studies have explored the effect of reward feedback on recognition memory, electrophysiological evidence for reward-enhanced memory and its underlying processing mechanisms remains unclear.

METHODS

This study adopts reward-learning and recognition memory tasks. Participants were asked to learn the reward values of two-color images (each color image had either reward or nonreward feedback) in the reward-learning task, and then tested their recognition memory performance with reward and nonreward feedback items.

RESULTS

Results demonstrated that the recognition memory performance of rewarded items was better than that of nonrewarded items. During the reward-learning period, nonreward feedback elicited larger feedback-related negativity (FRN) and P300 amplitudes compared with reward feedback. The findings indicated that participants mainly engaged in prediction error processing in the early stage, followed by comparing and context update of the learned items. During the recognition memory period, reward items elicited larger FN400 amplitude and smaller LPC amplitude compared with nonreward items. This suggests that reward item retrieval has deeper memory traces and can identify items faster, relying mainly on familiarity processing. Conversely, nonreward, as a general or inhibitory item, requires more detail and cognitive resources, that is, relies on recollection processing.

CONCLUSIONS

These findings indicated that participants had different process patterns between reward and nonreward items during recognition retrieval.

Eye-closure effects and the influence of short-term storage and processing capacity on episodic memory

Two experiments investigated differences in short-term storage and processing capacity on the magnitude of eye-closure effects on episodic memory. Experiment 1 compared individuals with high (vs. low) forward and backward spans in the free-recall of words retrieved under both eyes closed and open conditions. Main effects of both forward and backward span capacity (greater recall for the high span group) and eye-closure (higher recall with eyes closed) were found. Eye-closure was also associated with more "remember" responses. Experiment 2 compared individuals with high (vs. low) reading spans and found both main effects for reading span and eye-closure (greater recall for the high span group and with eyes closed). Remember responses were associated with both high reading span and eye-closure. The absence of interactions is discussed in terms of explanations of eye-closure effects that differentiate between modality-general and modality-specific processes.

Accelerated Long-Term Forgetting: Prolonged Delayed Recognition as Sensitive Measurement for Different Profiles of Long-Term Memory and Metacognitive Confidence in Stroke Patients

OBJECTIVE

Deficits in episodic memory are frequently reported after ischemic stroke. In standard clinical care, episodic memory is assessed after a 20-30 min delay, with abnormal memory decay over this period being characterized as rapid forgetting (RF). Previous studies have shown abnormal forgetting over a prolonged interval (days to weeks) despite normal acquisition, referred to as accelerated long-term forgetting (ALF).

METHOD

We examined whether ALF is present in stroke patients (N = 91) using immediate testing (T1), testing after a short delay (20-30 min, T2), and testing after a prolonged delay (one week, T3). Based on performance compared to matched controls (N = 85), patients were divided into (1) patients without forgetting, (2) patients with RF between T1 and T2, and (3) patients with ALF at T3. Furthermore, confidence ratings were assessed.

RESULTS

ALF was present in a moderate amount of stroke patients (17%), but ALF was even more prevalent in our stroke sample than RF after a 20-30 min delay (which was found in only 13% of our patients). Patients reported a lower confidence for their responses, independent of their actual performance.

CONCLUSIONS

Adding a one-week delayed measurement may potentially assist in identifying patients with memory decrements that may otherwise go undetected.

Effects of acute exercise on emotional memory

Research has demonstrated beneficial effects of acute exercise on memory for neutral materials, such as word lists of neutral valence/low arousal. However, the impacts of exercise on emotional memory is less understood. Across three laboratory experiments in college students, we tested if acute exercise could enhance both neutral and emotional memory performance, anticipating a greater effect for emotional memory. We examined effects of exercise at varying intensities (Experiment 1: high-intensity; Experiment 2: low- and high-intensity; Experiment 3: moderate-intensity), of diverse modalities (Experiment 1: treadmill jogging; Experiment 2: cycling; Experiment 3: open-skill (racquetball) and closed-skill (treadmill jogging) exercise), and on emotional memory performance assessed at increasing levels of hippocampal dependency (Experiment 1: Y/N recognition task; Experiment 2: paired-associative recognition task; Experiment 3: cued-recall task). We found that, in all experiments, acute exercise did not significantly influence emotional or neutral memory performance relative to sedentary control conditions. However, we observed several noteworthy outcomes indicating that acute exercise may be linked to improvements in memory confidence and accuracy for central aspects of emotional memory stimuli, and that select exercise modalities (e.g. treadmill exercise) may also be associated with increased frequency of memory intrusions.

Probing emotional recognition memory: how different response formats affect response behaviour

Receiver-operating characteristic curves from confidence ratings and remember/know (R/K) judgments are often used to estimate the contribution of familiarity and recollection to recognition memory. Both coming with specific advantages and disadvantages, which could be reduced by their combination. Little is known how the combination of both methods impacts response behaviour. This could be particularly important for emotional memory research, which is susceptible to variation in meta-mnemonic processes. We obtained reference performance indices from the two methods, instructing individuals to give confidence ratings or R/K judgments in one step. Against these, we contrasted R/K judgments in a two-step format and two combined formats, confidence ratings followed by R/K judgments and vice versa. Regarding reference formats, confidence ratings resulted in more liberal response criteria and false alarm rates than R/K judgments. Two-step R/K judgments and confidence ratings followed by R/K judgments resulted in patterns similar to one-step R/K judgments. Reversing the order resulted in more liberal response biases, higher hit and false alarms rates. Recollection and familiarity were unaffected by response formats. Valence effects did not vary with response formats. The present results suggest that confidence ratings followed by R/K judgments provide the advantages of both without biasing response behaviour.

Encoding and inhibition of arbitrary episodic context with abstract concepts

Context is critical for conceptual processing, but the mechanism underpinning its encoding and reinstantiation during abstract concept processing is unclear. Context may be especially important for abstract concepts-we investigated whether episodic context is recruited differently when processing abstract compared with concrete concepts. Experiments 1 and 2 presented abstract and concrete words in arbitrary contexts at encoding (Experiment 1: red/green colored frames; Experiment 2: male/female voices). Recognition memory for these contexts was worse for abstract concepts. Again using frame color and voice as arbitrary contexts, respectively, Experiments 3 and 4 presented words from encoding in the same or different context at test to determine whether there was a greater recognition memory benefit for abstract versus concrete concepts when the context was unchanged between encoding and test. Instead, abstract concepts were less likely to be remembered when context was retained. This suggests that at least some types of episodic context-when arbitrary-are attended less, and may even be inhibited, when processing abstract concepts. In Experiment 5, we utilized a context-spatial location-which (as we show) tends to be relevant during real-world processing of abstract concepts. We presented words in different locations, preserving or changing location at test. Location retention conferred a recognition memory advantage for abstract concepts. Thus, episodic context may be encoded with abstract concepts when context is relevant to real-world processing. The systematic contexts necessary for understanding abstract concepts may lead to arbitrary context inhibition, but greater attention to contexts that tend to be more relevant during real-world processing.

Conceptual knowledge modulates memory recognition of common items: The selective role of item-typicality

This work examines the influence of stored conceptual knowledge (i.e., schema and item-typicality) on conscious memory processes. Specifically, we tested whether item-typicality selectively modulates recollection and familiarity-based memories as a function of the availability of a categorical schema during encoding. Experiment 1 manipulated both encoding type (categorical vs. perceptual) and item-typicality (typical vs. atypical) in a single Remember-Know paradigm. Experiment 2 replicated and extended the previous study with a complementary source-memory task. In both experiments, we observed that typical items led to more Guess responses, while atypical items led to more Remember responses. These findings support the idea that the activation of a congruent categorical schema selectively enhances familiarity-based memories, likely due to the bypassing of the activated mechanisms for novel information. In contrast, atypical items improved recollective-based memories only, suggesting that their lesser fit with the stored prototype might have triggered those novelty processing mechanisms. Moreover, atypical items enhanced memory in the categorical condition for both item recognition and recollection memories only, suggesting an episodic gain due to inconsistency/novelty. The source memory results gave further credence to the argument that "Remember" judgments were based on truly recollective experiences and presented the same interaction between encoding type and item-typicality observed in recollective-based memories. Overall, the results suggest that the supposedly opposite conceptual knowledge effects actually coexist and interact, albeit selectively, in the modulation of recollection and familiarity processes.

Midazolam and Ketamine Produce Distinct Neural Changes in Memory, Pain, and Fear Networks during Pain

BACKGROUND

Despite the well-known clinical effects of midazolam and ketamine, including sedation and memory impairment, the neural mechanisms of these distinct drugs in humans are incompletely understood. The authors hypothesized that both drugs would decrease recollection memory, task-related brain activity, and long-range connectivity between components of the brain systems for memory encoding, pain processing, and fear learning.

METHODS

In this randomized within-subject crossover study of 26 healthy adults, the authors used behavioral measures and functional magnetic resonance imaging to study these two anesthetics, at sedative doses, in an experimental memory paradigm using periodic pain. The primary outcome, recollection memory performance, was quantified with d' (a difference of z scores between successful recognition versus false identifications). Secondary outcomes were familiarity memory performance, serial task response times, task-related brain responses, and underlying brain connectivity from 17 preselected anatomical seed regions. All measures were determined under saline and steady-state concentrations of the drugs.

RESULTS

Recollection memory was reduced under midazolam (median [95% CI], d' = 0.73 [0.43 to 1.02]) compared with saline (d' = 1.78 [1.61 to 1.96]) and ketamine (d' = 1.55 [1.12 to 1.97]; P < 0.0001). Task-related brain activity was detected under saline in areas involved in memory, pain, and fear, particularly the hippocampus, insula, and amygdala. Compared with saline, midazolam increased functional connectivity to 20 brain areas and decreased to 8, from seed regions in the precuneus, posterior cingulate, and left insula. Compared with saline, ketamine decreased connectivity to 17 brain areas and increased to 2, from 8 seed regions including the hippocampus, parahippocampus, amygdala, and anterior and primary somatosensory cortex.

CONCLUSIONS

Painful stimulation during light sedation with midazolam, but not ketamine, can be accompanied by increased coherence in brain connectivity, even though details are less likely to be recollected as explicit memories.

EDITOR’S PERSPECTIVE

The effects of psychosocial stress on item, cued-pair and emotional memory

Physical stress, such as from the cold-pressor test, has been robustly associated with altered memory retrieval, but it is less clear whether the same happens following psychosocial stress. Studies using psychosocial stressors report mixed effects on memory, leading to uncertainty about the common cognitive impact of both forms of stress. The current study uses a series of four carefully designed experiments, each differing by only a single critical factor to determine the effects of psychosocial stress on specific aspects of episodic memory. In three experiments, we induced psychosocial stress after participants encoded words, then assessed retrieval of those words after a prolonged delay. These experiments found no effect of post-encoding stress on recognition of neutral words or cued recall of word-pairs, but a small effect on recollection of semantically related words. There were, however, positive relationships within the stress group between measures of stress (cortisol in experiment 1 and self-reported-anxiety in experiment 3) and recollection of single word stimuli. In the fourth experiment, we found that psychosocial stress immediately before retrieval did not influence word recognition. Recollection, particularly for semantically related stimuli, may therefore be more susceptible to the effects of psychosocial stress, and future studies can assess how this relates to other forms of stress. Overall, our findings suggest that the effects of psychosocial stress on episodic memory may be more subtle than expected, warranting further exploration in larger studies.

The influence of negative emotional intensity on dual-processing recognition

Dual-processing theory assumes recognition memory involves two distinct processes: familiarity and recollection. Although the influence of emotional intensity on memory has been investigated, it remains unclear whether the influence of negative stimuli depends on familiarity or recollection. This study recorded event-related potentials as participants performed a modified remember/know procedure with highly negative, mildly negative, and neutral stimuli. The results showed that, relative to highly negative stimuli, mildly negative and neutral stimuli showed increased mean discrimination for responses of 'know' in the following pattern: highly negative < mildly negative < neutral. Neutral stimuli enhanced the frontal old/new effect. Relative to mildly negative and neutral stimuli, highly negative stimuli showed increased mean discrimination for responses of 'remember', and enhanced the parietal old/new effect. These results suggested negative emotional intensity influences recollection and familiarity differently, as recognition of highly negative stimuli depends on recollection, and recognition of neutral stimuli depends on familiarity.

Revisiting the remember-know task: Replications of Gardiner and Java (1990)

One of the most evidential behavioral results for two memory processes comes from Gardiner and Java (Memory & Cognition, 18, 23-30 1990). Participants provided more "remember" than "know" responses for old words but more know than remember responses for old nonwords. Moreover, there was no effect of word/nonword status for new items. The combination of a crossover interaction for old items with an invariance for new items provides strong evidence for two distinct processes while ruling out criteria or bias explanations. Here, we report a modern replication of this study. In three experiments, (Experiments 1, 2, and 4) with larger numbers of items and participants, we were unable to replicate the crossover. Instead, our data are more consistent with a single-process account. In a fourth experiment (Experiment 3), we were able to replicate Gardiner and Java's baseline results with a sure-unsure paradigm supporting a single-process explanation. It seems that Gardiner and Java's remarkable crossover result is not replicable.

The effect of intrinsic image memorability on recollection and familiarity

Many photographs of real-life scenes are very consistently remembered or forgotten by most people, making these images intrinsically memorable or forgettable. Although machine vision algorithms can predict a given image's memorability very well, nothing is known about the subjective quality of these memories: are memorable images recognized based on strong feelings of familiarity or on recollection of episodic details? We tested people's recognition memory for memorable and forgettable scenes selected from image memorability databases, which contain memorability scores for each image, based on large-scale recognition memory experiments. Specifically, we tested the effect of intrinsic memorability on recollection and familiarity using cognitive computational models based on receiver operating characteristics (ROCs; Experiment 1 and 2) and on remember/know (R/K) judgments (Experiment 2). The ROC data of Experiment 2 indicated that image memorability boosted memory strength, but did not find a specific effect on recollection or familiarity. By contrast, ROC data from Experiment 2, which was designed to facilitate encoding and, in turn, recollection, found evidence for a specific effect of image memorability on recollection. Moreover, R/K judgments showed that, on average, memorability boosts recollection rather than familiarity. However, we also found a large degree of variability in these judgments across individual images: some images actually achieved high recognition rates by exclusively boosting familiarity rather than recollection. Together, these results show that current machine vision algorithms that can predict an image's intrinsic memorability in terms of hit rates fall short of describing the subjective quality of human memories.

Episodic and semantic memory processes in the boundary extension effect: An investigation using the remember/know paradigm

BACKGROUND

Boundary extension (BE) is a phenomenon where participants report from memory that they have experienced more information of a scene than was initially presented. The goal of the current study was to investigate whether BE is fully based on episodic memory or also involves semantic scheme knowledge.

METHODS

The study incorporated the remember/know paradigm into a BE task. Scenes were first learned incidentally, with participants later indicating whether they remembered or knew that they had seen the scene before. Next, they had to rate 3 views - zoomed in, zoomed out or unchanged - of the original picture on similarity in closeness in order to measure BE.

RESULTS

The results showed a systematic BE pattern, but no difference in the amount of BE for episodic ('remember') and semantic ('know') memory. Additionally, the remember/know paradigm used in this study showed good sensitivity for both the remember and know responses.

DISCUSSION

The results suggest that BE might not critically depend on the contextual information provided by episodic memory, but rather depends on schematic knowledge shared by episodic and semantic memory. Schematic knowledge might be involved in BE by providing an expectation of what likely lies beyond the boundaries of the scene based on semantic guidance.

GEL CLASSIFICATION

2343 learning & memory.

Electrophysiological correlates of the perceptual fluency effect on recognition memory in different fluency contexts

The present study used event-related potentials (ERPs) to investigate the contribution of perceptual fluency to recognition memory in different fluency contexts. In a recognition memory test with a modified remember-know paradigm, we employed conceptually impoverished items (kaleidoscope images) as stimuli and manipulated the perceptual fluency of recognition test cues through masked repetition priming. There were two fluency context conditions. In the random fluency context (RC) condition, primed and unprimed trials were randomly inter-mixed. In the blocked fluency context (BC) condition, primed and unprimed trials were grouped into blocks. Behavioral results showed that priming elevated the incidence of remember hits and the accuracy of remember judgements in the RC condition; no such effects were evident in the BC condition. In addition, priming effects on reaction times were found only for remember hit responses in the RC condition. The ERP results revealed an early100-200 ms effect related to masked repetition priming, which took the form of greater positivity for primed than unprimed trials. This effect was modulated neither by fluency context or response type. The present findings suggest that perceptual fluency induced by masked repetition priming affects recollection-related memory judgments in a specific fluency context and indicate that relative, rather absolute, fluency plays a critical role in influencing recognition memory judgments.

Different definitions of the nonrecollection-based response option(s) change how people use the "remember" response in the remember/know paradigm

In the remember/know paradigm, a "know" response can be defined to participants as a high-confidence state of certainty or as a low-confidence state based on a feeling of familiarity. To examine the effects of definition on use of responses, in two experiments, definitions of "remember" and "guess" were kept constant, but definitions of "know" and/or "familiar" were systematically varied to emphasize (a) a subjective experience of high confidence without recollection, (b) a feeling of familiarity, (c) both of these subjective experiences combined within one response option, or (d) both of these experiences as separate response options. The confidence expressed in "know" and/or "familiar" definitions affected how participants used response options. Importantly, this included use of the "remember" response, which tended to be used more frequently when the nonrecollection-based middle response option emphasized a feeling of familiarity rather than an experience of "just knowing." The influence of the definitions on response patterns was greater for items that had undergone deep rather than shallow processing, and was greater when deep-encoded and shallow-encoded items were mixed, rather than blocked, at test. Our findings fit with previous research suggesting that the mnemonic traces underlying subjective judgments are continuous and that the remember/know paradigm is not a pure measure of underlying processes. Findings also emphasize the importance of researchers publishing the exact definitions they have used to enable accurate comparisons across studies.

Psychometric and electrodermal activity data from an experimental paradigm of memory encoding with some items periodically followed by painful electric shock

How pain influences explicit memory is an active area of investigation, and next-day recognition was the primary outcome of this experiment. The data reported here were secondary measures of psychometrics to quantify interindividual variability between subjects and measure electrodermal activity (EDA) changes in response to experimental stimuli. Reliable EDA responses following painful electric shocks were obtained in the Learning portion of the experiment. During next-day testing, however, no reliable EDA responses were elicited, including to previously pain-paired experimental items.

Face Validity of Remembering and Knowing: Empirical Consensus and Disagreement Between Participants and Researchers

Ever since Endel Tulving first distinguished between episodic and semantic memory, the remember/know paradigm has become a standard means of probing the phenomenology of participants’ memorial experiences by memory researchers, neuropsychologists, neuroscientists, and others. However, this paradigm has not been without its problems and has been used to capture many different phenomenological experiences, including retrieval from episodic versus semantic memory, recollection versus familiarity, strength of memory traces, and so on. We first conducted a systematic review of its uses across the literature and then examined how memory experts, other cognitive psychology experts, experts in other areas of psychology, and lay participants (Amazon Mechanical Turk workers) define what it means when one says “I remember” and “I know.” From coding their open-ended responses using a number of theory-bound dimensions, it seems that lay participants do not see eye to eye with memory experts in terms of associating “I remember” responses with recollection and “I know” responses with familiarity. However, there is general consensus with Tulving’s original distinction, linking remembering with memory for events and knowing with semantic memory. Recommendations and implications across fields are discussed.

Varieties of recollective experience

Four variants on Tulving's "Remember/Know" paradigm supported a tripartite classification of recollective experience in recognition memory into Remembering (as in conscious recollection of a past episode), Knowing (similar to retrieval from semantic memory), and Feeling (a priming-based judgment of familiarity). Recognition-by-knowing and recognition-by-feeling are differentiated by level of processing at the time of encoding (Experiments 1-3), shifts in the criterion for item recognition (Experiment 2), response latencies (Experiments 1-3), and changes in the response window (Experiment 3). False recognition is often accompanied by "feeling", but rarely by "knowing"; d' is higher for knowing than for feeling (Experiments 1-4). Recognition-by-knowing increases with additional study trials, while recognition-by-feeling falls to zero (Experiment 4). In these ways, recognition-by-knowing is distinguished from recognition-by-feeling in much the same way as, in the traditional Remember/Know paradigm, recognition-by-remembering can be distinguished from recognition-without-remembering. Implications are discussed for dual-process theories of memory, and the search for the neural substrates of memory retrieval.

Thalamic-Medial Temporal Lobe Connectivity Underpins Familiarity Memory

The neural basis of memory is highly distributed, but the thalamus is known to play a particularly critical role. However, exactly how the different thalamic nuclei contribute to different kinds of memory is unclear. Moreover, whether thalamic connectivity with the medial temporal lobe (MTL), arguably the most fundamental memory structure, is critical for memory remains unknown. We explore these questions using an fMRI recognition memory paradigm that taps familiarity and recollection (i.e., the two types of memory that support recognition) for objects, faces, and scenes. We show that the mediodorsal thalamus (MDt) plays a material-general role in familiarity, while the anterior thalamus plays a material-general role in recollection. Material-specific regions were found for scene familiarity (ventral posteromedial and pulvinar thalamic nuclei) and face familiarity (left ventrolateral thalamus). Critically, increased functional connectivity between the MDt and the parahippocampal (PHC) and perirhinal cortices (PRC) of the MTL underpinned increases in reported familiarity confidence. These findings suggest that familiarity signals are generated through the dynamic interaction of functionally connected MTL-thalamic structures.

Evidence for adult age-invariance in associative false recognition

Older people are more prone to memory distortions and errors than young people, but do not always show greater false recognition in the Deese-Roediger-McDermott (DRM) task. We report two preregistered experiments investigating whether recent findings of age-invariant false recognition extend to designs in which studied items are blocked. According to (Tun, P. A., Wingfield, A., Rosen, M. J., & Blanchard, L. (1998). Response latencies for false memories: Gist-based processes in normal aging. Psychology and Aging, 13(2), 230-241.), age effects on false recognition in the DRM task are due to a greater reliance on gist processing which is enhanced under blocked study conditions. Experiment 1 assessed false recognition in an online variant of the DRM task where words were presented visually, with incidental encoding. The results showed Bayesian evidence against greater false recognition by older adults, whether lures were semantically associated with studied lists, or perceptually related (presented in the same distinctive font as studied lists) or both. Experiment 2 used a typical DRM procedure with auditory lists and intentional encoding, closely reproducing (Tun, P. A., Wingfield, A., Rosen, M. J., & Blanchard, L. (1998). Response latencies for false memories: Gist-based processes in normal aging. Psychology and Aging, 13(2), 230-241.) Experiment 2 but omitting an initial test of recall. The results showed evidence against an age-related increase in critical lure false recognition under these conditions. Together, the data suggest that older people do not make more associative memory errors in recognition tests than young people.

Saccade-induced retrieval enhancement and the recovery of perceptual item-specific information

Saccade-induced retrieval enhancement (SIRE) effects refer to the finding that memory can be enhanced when a short period of saccadic eye movements takes place prior to retrieval. Previous published work testifies to this eye movement advantage, but no work has yet examined if SIRE effects can be found when retrieval demands are high as a result of testing non-studied memoranda that are identical in name/conceptual codes, similar in perceptual features, but differ in terms of perceptual-item-specific information. The results indicate SIRE effects can be found under such conditions and are independent of encoding orientation (intentional vs. incidental). More particularly, SIRE effects manifested themselves in terms of the retrieval of item-specific detail and recollection (vs. familiarity). In terms of the latter, recollection but not familiarity was enhanced by eye movements. These findings are considered in the context of extant theories of SIRE and related research.

A role for familiarity in supporting the testing effect over time

Endel Tulving (1985) drew a distinction between Remembering and Knowing, spurring a great deal of research on the memorial experiences of recollection and familiarity and their contribution to various phenomena in memory. More recently, studies have used this distinction to situate our understanding of the processes that contribute to the testing effect-or, the benefit of retrieval practice to later memory (see also Tulving, 1967). Using retention intervals of approximately 15 min or less between initial and final testing, several studies have found that initial testing magnifies estimates of recollection but not familiarity, regardless of whether a testing effect is revealed in overall recognition performance (Chan and McDermott, 2007). However, the efficacy of prior testing in enhancing memory has been shown to change over time, as have estimates of recollection and familiarity. Thus, the mechanisms that underlie the quintessential testing effect-one that occurs in overall recognition or recall over longer delays-are still uncertain. To investigate this issue, in two experiments, subjects studied word lists, took 3-letter stem cued-recall tests on half of the studied words, and completed a final recognition test in which estimates of recollection and familiarity were obtained via confidence (Experiment 1) or Remember-Know-New (Experiment 2) judgments. Critically, final recognition tests occurred either immediately, 1 day (Experiment 1 only), or 4 days after initial learning. At all retention intervals and in both methods of estimating recollection and familiarity on the final test (i.e. receiver-operating characteristic and remember-know analyses), initial testing magnified estimates of both recollection and familiarity. These findings suggest that the testing effect can result from changes in both processes and pose issues for theories of the testing effect that consider an exclusive role for recollection.

The effect of conceptual priming on subsequent familiarity: Behavioral and electrophysiological evidence

Previous studies on the neural mechanisms of how priming influences subsequent recognition memory have mainly focused on repetition priming, whereas the neural mechanisms of how conceptual priming affects subsequent recognition memory is still not clear. The present study investigated the electrophysiological correlates of how conceptual priming influences subsequent recognition memory. The behavioral results showed that conceptual priming only affected subsequent familiarity. The ERP results showed that conceptual priming was associated with reduced N400, and that the N400 conceptual priming effect predicted the behavioral effect of conceptual priming on subsequent familiarity. These results indicated that conceptual priming could influence subsequent familiarity by facilitating semantic processing in the encoding phase.

Memory for non-painful auditory items is influenced by whether they are experienced in a context involving painful electrical stimulation

In this study, we sought to examine the effect of experimentally induced somatic pain on memory. Subjects heard a series of words and made categorization decisions in two different conditions. One condition included painful shocks administered just after presentation of some of the words; the other condition involved no shocks. For the condition that included painful stimulations, every other word was followed by a shock, and subjects were informed to expect this pattern. Word lists were repeated three times within each condition in randomized order, with different category judgments but consistent pain-word pairings. After a brief delay, recognition memory was assessed. Non-pain words from the pain condition were less strongly encoded than non-pain words from the completely pain-free condition. Recognition of pain-paired words was not significantly different than either subgroup of non-pain words. An important accompanying finding is that response times to repeated experimental items were slower for non-pain words from the pain condition, compared to non-pain words from the completely pain-free condition. This demonstrates that the effect of pain on memory may generalize to non-pain items experienced in the same experimental context.