Familiarity-based Memory Research Articles

Schema-congruency supports the formation of unitized representations: Evidence from event-related potentials

The main goal of the present study was to investigate whether schema-based encoding of novel word pairs (i.e., novel compound words) supports the formation of unitized representations and thus, associative familiarity-based recognition. We report two experiments that both comprise an incidental learning task, in which novel noun-noun compound words were presented in semantically congruent contexts, enabling schema-supported processing of both constituents, contrasted with a schema-neutral condition. In Experiment 1, the effects of schema congruency on memory performance were larger for associative memory performance than for item memory performance in a memory test in which intact, recombined, and new compound words had to be discriminated. This supports the view that schema congruency boosts associative memory by promoting unitization. When contrasting event-related potentials (ERPs) for hits with correct rejections or associative misses, an N400 attenuation effect (520–676 ms) indicating absolute familiarity was present in the congruent condition, but not in the neutral condition. In line with this, a direct comparison of ERPs on hits across conditions revealed more positive waveforms in the congruent than in the neutral condition. This suggests that absolute familiarity contributes to associative recognition memory when schema-supported processing is established. In Experiment 2, we tested whether schema congruency enables the formation of semantically overlapping representations. Therefore, we included semantically similar lure compound words in the test phase and compared false alarm rates to these lures across conditions. In line with our hypothesis, we found higher false alarm rates in the congruent as compared to the neutral condition. In conclusion, we provide converging evidence for the view that schema congruency enables the formation of unitized representations and supports familiarity-based memory retrieval.

The anterior medial hippocampus contributes to both recall and familiarity-based memory for scenes

The hippocampus is usually associated with recall memory, whereas its contribution to familiarity-based memory is debated. Growing evidence support the idea that this structure participates to any cognitive process performed on scene representations. In parallel, differences in functional specialisation and cortical connectivity were found across the longitudinal and transverse axes of the hippocampus. Here we reanalysed functional MRI data from 51 participants showing stronger engagement of the hippocampus in recall, familiarity-based recognition and rejection, and visual discrimination, of scenes compared to single objects. A conjunction analysis between these four tasks revealed a set of occipital, medial temporal, posterior cingulate, and parietal regions, matching the scene construction network described in the literature. Crucially, we found that the anterior medial part of the hippocampus was consistently involved in all tasks investigated for scene stimuli. These findings support that the hippocampus can contribute to both recall and familiarity-based memory, depending on stimulus type. More generally, this bolsters the recent proposal that circumscribed regions within the hippocampus may underpin specific cognitive mechanisms.

Relationships between age, fMRI correlates of familiarity and familiarity-based memory performance under single and dual task conditions

Using fMRI, we investigated the effects of age and divided attention on the neural correlates of familiarity and their relationship with memory performance. At study, word pairs were visually presented to young and older participants under the requirement to make a relational judgment on each pair. Participants were then scanned while undertaking an associative recognition test under single and dual (auditory tone detection) task conditions. The test items comprised studied, rearranged (words from different studied pairs) and new word pairs. fMRI familiarity effects were operationalized as greater activity elicited by studied pairs incorrectly identified as ‘rearranged’ than by correctly rejected new pairs. The reverse contrast was employed to identify ‘novelty’ effects. Behavioral familiarity estimates were equivalent across age groups and task conditions. Robust fMRI familiarity effects were identified in several regions, including medial and superior lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate. fMRI novelty effects were identified in the anterior medial temporal lobe. Both familiarity and novelty effects were largely age-invariant and did not vary, or varied minimally, according to task condition. In addition, the familiarity effects correlated positively with a behavioral estimate of familiarity strength irrespective of age. These findings extend a previous report from our laboratory, and converge with prior behavioral reports, in demonstrating that the factors of age and divided attention have little impact on behavioral and neural estimates of familiarity.

Slow judgments of learning predict familiarity-based memories as measured by the remember-know task.

Dual-process theories of memory assume that memory is based on recollection and familiarity. A few dual-process approaches to metacognition have been proposed, which assume that metacognitive judgments, including judgments of learning (JOLs) or predictions about the likelihood of recall, are based on two, or slow and fast, processes. Prior research suggests that JOLs are generally linked to recollection and familiarity (e.g., higher JOLs for recollected items). However, the basis of JOLs is still unknown. Measuring JOL latency as well as magnitude, the present study investigated the underlying processes of JOLs for items that would be classified by the remember-know procedure in cued recall paradigms. Four experiments yielded three findings from individual experiment analyses and meta-analyses. First, high, middle, and low JOLs were assigned to items that received remember, know, and no-memory judgments, respectively. Second, JOL latencies were the longest for items that received a know judgment. For each, the effect was larger for delayed (vs. immediate) JOLs. Finally, in each JOL condition, there was no support for the idea that the relative accuracy of JOLs increases when memory performance is exclusively defined as items that received a remember judgment. Most importantly, the finding of JOL latency suggests that during study, middle-level JOLs are made on the basis of deliberate processes, which is consistent with dual-process approaches to JOLs, for items recalled with a know judgment at test. Discussions include possible processes leading to slow middle-level JOLs and relations of JOLs to recollection/familiarity, and theoretical/methodological issues with using the remember-know procedure. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Patterns of retrieval-related cortico-striatal connectivity are stable across the adult lifespan.

Memory retrieval effects in the striatum are well documented and robust across experimental paradigms. However, the functional significance of these effects, and whether they are moderated by age, remains unclear. We used functional magnetic resonance imaging paired with an associative recognition task to examine retrieval effects in the striatum in a sample of healthy young, middle-aged, and older adults. We identified anatomically segregated patterns of enhanced striatal blood oxygen level-dependent (BOLD) activity during recollection- and familiarity-based memory judgments. Successful recollection was associated with enhanced BOLD activity in bilateral putamen and nucleus accumbens, and neither of these effects were reliably moderated by age. Familiarity effects were evident in the head of the caudate nucleus bilaterally, and these effects were attenuated in middle-aged and older adults. Using psychophysiological interaction analyses, we observed a monitoring-related increase in functional connectivity between the caudate and regions of the frontoparietal control network, and between the putamen and bilateral retrosplenial cortex and intraparietal sulcus. In all instances, monitoring-related increases in cortico-striatal connectivity were unmoderated by age. These results suggest that the striatum, and the caudate in particular, couples with the frontoparietal control network to support top-down retrieval-monitoring operations, and that the strength of these inter-regional interactions is preserved in later life.

The Distinctive Pattern of Declarative Memories in Autism Spectrum Disorder: Further Evidence of Episodic Memory Constraints.

This study examines declarative memory retrieval in ASD depending on the availability and access to stored conceptual knowledge. Fifteen autistic participants and a matched control group of 18 typically-developed (TD) volunteers completed a Remember-Know paradigm manipulated by encoding-type (categorical, perceptual) and item-typicality (high-typical, low-typical). The autistic group showed worse and slower recognition and less recollection but equivalent familiarity-based memories compared to TDs. Notably, low-typical items did not improve their memories as they did for TDs, likely due to difficulties in matching low-fit information to the stored schema. Results suggest that memory decline in ASD may derive from the episodic system and its dynamics with the semantic system. These findings may inform interventional strategies for enhancing learning abilities in ASD.

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.

Self-referential encoding of source information in recollection memory.

Information that is encoded in relation to the self has been shown to be better remembered, yet reports have disagreed on whether the memory benefit from self-referential encoding extends to source memory (the context in which information was learned). In this study, we investigated the self-referential effect on source memory in recollection and familiarity-based memory. Using a Remember/Know paradigm, we compared source memory accuracy under self-referential encoding and semantic encoding. Two types of source information were included, a "peripheral" source which was not inherent to the encoding activity, and a source information about the encoding context. We observed the facilitation in item memory from self-referential encoding compared to semantic encoding in recollection but not in familiarity-based memory. The self-referential benefit to source accuracy was observed in recollection memory, with source memory for the encoding context being stronger in the self-referential condition. No significant self-referential effect was observed with regards to peripheral source information (information not required for the participant to focus on), suggesting not all source information benefit from self-referential encoding. Self-referential encoding also resulted in a higher ratio of "Remember/Know" responses rate than semantically encoded items, denoting stronger recollection. These results suggest self-referential encoding creates a richer, more detailed memory trace which can be recollected later on.

Paranoia is associated with impaired novelty detection and overconfidence in recognition memory judgments.

False recognition, or the mis-categorization of a "new" stimulus as "old," might support fixed false beliefs by blocking new learning or otherwise contributing to internal representations of the world that are at odds with reality. However, the mechanisms through which false recognition is facilitated among paranoid individuals remain unclear. We examined 2 phenomena that may contribute to this effect: an overreliance on fluency-based processes during recognition, manifesting as a lower threshold for judging items as recently studied, and a propensity to require less information to come to a highly confident judgment. The former would be expected to be particularly pronounced among items that are generally familiar, as opposed to completely novel. Here, we manipulated familiarity in a recognition memory paradigm by using stimuli that varied in their rate of extraexperimental exposure (i.e., real words vs. pseudowords). Further, to determine whether paranoia was associated with a tendency to differentially misallocate confidence to errors, we calculated a hierarchical Bayesian estimate of metacognitive sensitivity (meta-d') in addition to the more classic d'. In line with our hypotheses, paranoia was associated with an increased rate of false alarm errors, differentially so for familiar versus unfamiliar stimuli, suggesting that a context-agnostic, familiarity-based memory system might underlie observed memory distortions. What's more, paranoia was associated with heightened confidence on error trials and reduced metacognitive sensitivity. These findings highlight 2 distinct deficits-in both novelty detection and metacognitive monitoring-that contribute to false recognition judgments, offering targets for cognitive interventions to reduce memory distortion among paranoid individuals. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The spatial distribution of attention predicts familiarity strength during encoding and retrieval.

The memories we form are determined by what we attend to, and conversely, what we attend to is influenced by our memory for past experiences. Although we know that shifts of attention via eye movements are related to memory during encoding and retrieval, the role of specific memory processes in this relationship is unclear. There is evidence that attention may be especially important for some forms of memory (i.e., conscious recollection), and less so for others (i.e., familiarity-based recognition and unconscious influences of memory), but results are conflicting with respect to both the memory processes and eye movement patterns involved. To address this, we used a confidence-based method of isolating eye movement indices of spatial attention that are related to different memory processes (i.e., recollection, familiarity strength, and unconscious memory) during encoding and retrieval of real-world scenes. We also developed a new method of measuring the dispersion of eye movements, which proved to be more sensitive to memory processing than previously used measures. Specifically, in 2 studies, we found that familiarity strength-that is, changes in subjective reports of memory confidence-increased with (a) more dispersed patterns of viewing during encoding, (b) less dispersed viewing during retrieval, and (c) greater overlap in regions viewed between encoding and retrieval (i.e., resampling). Recollection was also related to these eye movements in a similar manner, though the associations with recollection were less consistent across experiments. Furthermore, we found no evidence for effects related to unconscious influences of memory. These findings indicate that attentional processes during viewing may not preferentially relate to recollection, and that the spatial distribution of eye movements is directly related to familiarity-based memory during encoding and retrieval. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Impaired recollection-based episodic memory as a cognitive endophenotype in schizophrenia

ABSTRACT Introduction Patients with schizophrenia show impaired recollection but largely preserved familiarity-based episodic memory. This study was done to clarify the endophenotypic nature of recollection and familiarity-based episodic memory in schizophrenia and the role of emotional valence of memoranda and degree of recall confidence in it. Method Twenty-five patients with schizophrenia, one unaffected sibling of each patient, and twenty-three healthy controls completed two tasks assessing recollection and familiarity-based processes in episodic memory. In the first task, participants were asked to remember positive, negative, and neutral emotional valence words in a remember–know paradigm. In the second task, in addition to recollection and familiarity-based responses, participants were asked to make confidence judgments about their responses. Results Patients with schizophrenia and their first-degree relatives (FDRs) performed poorly on recollection but not familiarity-based responses, compared to healthy controls; performance of first-degree relatives was in between and significantly different from that of both patients and controls. The differences in recollection and familiarity-based responses across the three groups were not moderated by recall confidence judgments or emotional valence of memoranda. Furthermore, there was no correlation between recollection-based memory impairments and duration or severity of illness or current medication exposure. Conclusions Impaired recollection-based memory constitutes a potential cognitive endophenotype in schizophrenia. Furthermore, selective impairment of recollection-based, but sparing of familiarity-based, memory in patients and their FDRs supports the distinct nature of recollection and familiarity-based episodic memories.

The impact of focused attention on subsequent emotional recollection: A functional MRI investigation

In his seminal works, Endel Tulving argued that functionally distinct memory systems give rise to subjective experiences of remembering and knowing (i.e., recollection- vs. familiarity-based memory, respectively). Evidence shows that emotion specifically enhances recollection, and this effect is subserved by a synergistic mechanism involving the amygdala (AMY) and hippocampus (HC). In extreme circumstances, however, uncontrolled recollection of highly distressing memories may lead to symptoms of affective disorders. Therefore, it is important to understand the factors that can diminish such detrimental effects. Here, we investigated the effects of Focused Attention (FA) on emotional recollection. FA is an emotion regulation strategy that has been proven quite effective in reducing the impact of emotional responses associated with the recollection of distressing autobiographical memories, but its impact during emotional memory encoding is not known. Functional MRI and eye-tracking data were recorded while participants viewed a series of composite negative and neutral images with distinguishable foreground (FG) and background (BG) areas. Participants were instructed to focus either on the FG or BG content of the images and to rate their emotional responses. About 4 days later, participants’ memory was assessed using the R/K procedure, to indicate whether they Recollected specific contextual details about the encoded images or the images were just familiar to them – i.e., participants only Knew that they saw the pictures without being able to remember specific contextual details. First, results revealed that FA was successful in decreasing memory for emotional pictures viewed in BG Focus condition, and this effect was driven by recollection-based retrieval. Second, the BG Focus condition was associated with decreased activity in the AMY, HC, and anterior parahippocampal gyrus for subsequently recollected emotional items. Moreover, correlation analyses also showed that reduced activity in these regions predicted greater reduction in emotional recollection following FA. These results demonstrate the effectiveness of FA in mitigating emotional experiences and emotional recollection associated with unpleasant emotional events.

P.533 Sleep and cognitive functions in typically developing and drug-naïve ADHD children

In his seminal works, Endel Tulving argued that functionally distinct memory systems give rise to subjective experiences of remembering and knowing (i.e., recollection- vs. familiarity-based memory, respectively). Evidence shows that emotion specifically enhances recollection, and this effect is subserved by a synergistic mechanism involving the amygdala (AMY) and hippocampus (HC). In extreme circumstances, however, uncontrolled recollection of highly distressing memories may lead to symptoms of affective disorders. Therefore, it is important to understand the factors that can diminish such detrimental effects. Here, we investigated the effects of Focused Attention (FA) on emotional recollection. FA is an emotion regulation strategy that has been proven quite effective in reducing the impact of emotional responses associated with the recollection of distressing autobiographical memories, but its impact during emotional memory encoding is not known. Functional MRI and eye-tracking data were recorded while participants viewed a series of composite negative and neutral images with distinguishable foreground (FG) and background (BG) areas. Participants were instructed to focus either on the FG or BG content of the images and to rate their emotional responses. About 4 days later, participants’ memory was assessed using the R/K procedure, to indicate whether they Recollected specific contextual details about the encoded images or the images were just familiar to them – i.e., participants only Knew that they saw the pictures without being able to remember specific contextual details. First, results revealed that FA was successful in decreasing memory for emotional pictures viewed in BG Focus condition, and this effect was driven by recollection-based retrieval. Second, the BG Focus condition was associated with decreased activity in the AMY, HC, and anterior parahippocampal gyrus for subsequently recollected emotional items. Moreover, correlation analyses also showed that reduced activity in these regions predicted greater reduction in emotional recollection following FA. These results demonstrate the effectiveness of FA in mitigating emotional experiences and emotional recollection associated with unpleasant emotional events.

Distinct disease‐sensitive GABAergic neurons in the perirhinal cortex of Alzheimer's mice and patients

Neuronal loss is the best neuropathological substrate that correlates with cortical atrophy and dementia in Alzheimer's disease (AD). Defective GABAergic neuronal functions may lead to cortical network hyperactivity and aberrant neuronal oscillations and in consequence, generate a detrimental alteration in memory processes. In this study, using immunohistochemical and stereological approaches, we report that the two major and non‐overlapping groups of inhibitory interneurons (SOM‐cells and PV‐cells) displayed distinct vulnerability in the perirhinal cortex of APP/PS1 mice and AD patients. SOM‐positive neurons were notably sensitive and exhibited a dramatic decrease in the perirhinal cortex of 6‐month‐old transgenic mice (57% and 61% in areas 36 and 35, respectively) and, most importantly, in AD patients (91% in Braak V–VI cases). In addition, this interneuron degenerative process seems to occur in parallel, and closely related, with the progression of the amyloid pathology. However, the population expressing PV was unaffected in APP/PS1 mice while in AD brains suffered a pronounced and significant loss (69%). As a key component of cortico‐hippocampal networks, the perirhinal cortex plays an important role in memory processes, especially in familiarity‐based memory recognition. Therefore, disrupted functional connectivity of this cortical region, as a result of the early SOM and PV neurodegeneration, might contribute to the altered brain rhythms and cognitive failures observed in the initial clinical phase of AD patients. Finally, these findings highlight the failure of amyloidogenic AD models to fully recapitulate the selective neuronal degeneration occurring in humans.

Conscious and unconscious memory differentially impact attention: Eye movements, visual search, and recognition processes

A hotly debated question is whether memory influences attention through conscious or unconscious processes. To address this controversy, we measured eye movements while participants searched repeated real-world scenes for embedded targets, and we assessed memory for each scene using confidence-based methods to isolate different states of subjective memory awareness. We found that memory-informed eye movements during visual search were predicted both by conscious recollection, which led to a highly precise first eye movement toward the remembered location, and by unconscious memory, which increased search efficiency by gradually directing the eyes toward the target throughout the search trial. In contrast, these eye movement measures were not influenced by familiarity-based memory (i.e., changes in subjective reports of memory strength). The results indicate that conscious recollection and unconscious memory can each play distinct and complementary roles in guiding attention to facilitate efficient extraction of visual information.

Increasing Dopamine and Acetylcholine Levels during Encoding Does Not Modulate Remember or Know Responses during Memory Retrieval in Healthy Aging—a Randomized Controlled Feasibility Study

The retrieval of information from long-term memory can be associated with information regarding sources or context (recollection) or without further context (familiarity). The retrieval type depends on how information has been encoded previously, and this encoding process is supposed to be modulated by the neurotransmitters dopamine and acetylcholine. For example, acetylcholine levels in the hippocampus increase when one is confronted with novel information allowing for better encoding and, presumably, for retrieval of more detailed memories (recollection). On the other hand, a dopaminergic deficit such as in Parkinson’s disease has been shown to induce deficits in familiarity rather than in recollection-based retrieval. It is, however, unclear whether this finding arises from alterations in encoding, retrieval, or both. Moreover, other research has challenged this clear-cut dichotomy and linked dopamine to both familiarity and recollection, and acetylcholine to unspecific enhancement of memory for novel information. Thirty-nine healthy seniors (age range 62–77) participated in a remember/know task in which scenes that were presented with different repetition rates had to be encoded and retrieved on the following day. Neurotransmitter levels were modulated during encoding by administrating either levodopa (100 mg, N = 13) or galantamine (8 mg, N = 13) to one of two experimental groups. A third group received a placebo (N = 13). Across all groups, recognition memory increased as a function of stimulus repetition, and this effect was specifically pronounced for remember relative to know answers. Importantly, the drugs had no effect on recollection, familiarity, or overall recognition memory. The findings argue against a simple dichotomy of dopaminergic and cholinergic contributions to either recollection- or familiarity-based memory retrieval.

Cutting out the middleman: Separating attributional biases from memory deficits.

Bastin and colleagues present an integrative model of how recollection- and familiarity-based memories are represented in the brain. While they emphasize the role of attribution mechanisms in shaping memory retrieval, prior work examining implicit memory suggests that memory deficits may be better understood by separating attributional biases from the underlying memory traces.

Priming recognition memory test cues: No evidence for an attributional basis of recollection.

We argue that while the proposed memory model by Bastin et al. can explain familiarity-based memory judgements through the interaction of a core representation system and an attribution system, recollection-based memory judgements are not based on non-mnemonic signals being attributed to memory.

Dietary effects on object recognition: The impact of high-fat high-sugar diets on recollection and familiarity-based memory.

Exposure to a high-fat high-sugar (HFHS) diet rapidly impairs novel-place- but not novel-object-recognition memory in rats (Tran & Westbrook, 2015, 2017). Three experiments sought to investigate the generality of diet-induced cognitive deficits by examining whether there are conditions under which object-recognition memory is impaired. Experiments 1 and 3 tested the strength of short- and long-term object-memory trace, respectively, by varying the interval of time between object familiarization and subsequent novel object test. Experiment 2 tested the effect of increasing working memory load on object-recognition memory by interleaving additional object exposures between familiarization and test in an n-back style task. Experiments 1-3 failed to detect any differences in object recognition between HFHS and control rats. Experiment 4 controlled for object novelty by separately familiarizing both objects presented at test, which included one remote-familiar and one recent-familiar object. Under these conditions, when test objects differed in their relative recency, HFHS rats showed a weaker memory trace for the remote object compared to chow rats. This result suggests that the diet leaves intact recollection judgments, but impairs familiarity judgments. We speculate that the HFHS diet adversely affects "where" memories as well as the quality of "what" memories, and discuss these effects in relation to recollection and familiarity memory models, hippocampal-dependent functions, and episodic food memories. (PsycINFO Database Record

Supplemental Material for Dietary Effects on Object Recognition: The Impact of High-Fat High-Sugar Diets on Recollection and Familiarity-Based Memory

Supplemental Material for Dietary Effects on Object Recognition: The Impact of High-Fat High-Sugar Diets on Recollection and Familiarity-Based Memory