Dual-process theory and signal-detection theory of recognition memory

Tulving's (1989) Doctrine of Concordance Revisited

The Doctrine of Concordance is the implicit assumption that cognitive processes, behavior, and phenomenological experience are highly correlated (Tulving, 1989). Tulving challenged this assumption, pointing to domains in which conscious experience did not accompany a particular measured cognitive process and to situations in which consciousness did not correlate with the observable behavior. Schwartz (1999) extended this view, asserting that the underlying cognitive processes that produce conscious experience may differ from those that produce observable behavior. Though research on conscious experience blossomed during the last quarter century and progress has been made in moving past the Doctrine of Concordance, we argue that some subdomains within memory research remain hampered by an implicit endorsement of it. We outline two areas of memory research in which current research and interpretations appear to fall prey to the Doctrine today: research on the dual- vs. single-process theory in recognition memory, including work on remember/know judgments, and research on retrospective memory confidence. We then describe four areas of research that show progress in understanding conscious experience by rejecting the Doctrine of Concordance: These are 1) metacognitive disconnects in the science of learning, 2) recognition illusions, 3) déjà vu experiences, and 4) aha experiences. We claim that there is often a dissociation between the mechanisms that create conscious experience and the underlying cognitive processes that contribute to behaviors, which may seem causally correlated with conscious experience. Disentangling the relations between process, behavior, and conscious experience in the human mind's operation are important to understanding it.

Effects of physical activity on smartphone addiction in Chinese college students-chain mediation of self-control and stress perception

PURPOSE

With the advancement of technology and widespread smartphone use, addiction to these devices has escalated, particularly among college students. This issue transcends mere habit, impacting physical, psychological, and social well-being. Prolonged screen exposure and excessive app engagement contribute to vision and hearing deterioration, alongside heightened psychological stress and diminished social skills. The dual-process theory offers a unique lens to explore the intricate dynamics of smartphone addiction. Incorporating physical activity as a healthy lifestyle choice can bolster self-control and mitigate the allure of smartphones by enhancing physical engagement.

METHODS

A total of 559 college students from two universities, Wuhan University of Science and Technology and Central China Normal University, were surveyed using the Physical Activity Scale, Stress Perception Scale, self-control Scale, and smartphone Addiction Burnout Scale. The questionnaire was statistically analyzed using SPSS 27.0 statistical analysis software. Correlation analysis, regression analysis, and mediation model were used to evaluate the relationships among physical activity, self-control, stress perception, and smartphone addiction among college students.

RESULTS

Physical activity was a significant negative predictor of smartphone addiction among college students(β = -0.038, p < 0.001), and with the addition of the intermediate variables (self-control and stress perception), physical activity remained a significant negative predictor of smartphone addiction among college students (β = -0.017,p < 0.01).

CONCLUSION

Physical activity and self-control negatively predicted smartphone addiction, and stress perception was a negative predictor of smartphone addiction;self-control mediates in physical activity and smartphone addiction;stress perception mediates physical activity and smartphone addiction;self-control and stress perception play a chain mediating role in physical activity and smartphone addiction.

Are emotional stimuli prioritised in visual awareness?

Although various features of visual stimuli have been shown to affect access to awareness, it is still unclear whether and to what extent emotional stimuli have privileged access to visual awareness. We conducted three online experiments, using a breaking Repeated Masked Suppression (bRMS) paradigm, to assess whether positively and negatively valenced/high-arousal photographs would emerge from masking (break out of forward/backward masking by image-unique masks) faster than would neutral/low-arousal photographs. Experiment 1 found that positively-valenced high-arousal pictures were faster to break out of repeated masked suppression. Experiment 2 showed that this was not because such pictures were substantially more memorable. Experiment 3 used a verbal rather than pictorial method to check for accuracy of breakout, and found similar results to Experiment 1. We also found that various pictorial qualities had either no effect, or only a minor effect, on our results. Importantly, images of people and animals consistently showed the shortest breakout times, indicating that such stimuli might be especially available to conscious access. However, a difference in the distribution of images of people (fastest) and scenes (slowest) images across the valence categories may have also contributed to the overall shorter breakout times of positively-valenced images.

Oxytocin does not impact forced-choice recognition memory in an experimental trauma film paradigm with healthy women

Introduction

Traumatic experiences are thought to alter memory acquisition and consolidation. Cognitive models of PTSD suggest that voluntary and involuntary memories after trauma can be independently addressed through interventions. The administration of oxytocin before exposure to a trauma film led to more intrusive (involuntary) memories than placebo. The effect of oxytocin on voluntary memory of the traumatic film, however, remains unclear. The current study aimed to assess whether intranasal oxytocin administration facilitates forced-choice recognition memory after a trauma film paradigm.

Material & methods

We performed a pooled analysis of two randomized, double-blind, placebo-controlled studies (N = 437) to assess the impact of intranasal oxytocin administration on declarative memory. Participants received 24 I.U. of oxytocin, either 40 minutes before a trauma film paradigm or immediately afterward. We applied a forced-choice recognition task seven days after the trauma film paradigm. The task comprised pre-, peri, and post-trauma film scene details.

Results

The administration of oxytocin did not affect recognition performance for any film scene (F(2, 401) = .49, p = .61). Participants remembered significantly more peri-traumatic film details compared to pre- and post-trauma details (F(1.72, 802) = 103.38, p <.001).

Discussion

Although the exogenous oxytocin administration before a trauma film has been shown to influence the acquisition of intrusive memories, it does not seem to affect the recognition memory of trauma film details. That aligns with cognitive models of PTSD, suggesting that voluntary and involuntary memory after trauma can be independently addressed through experimental interventions.

Zooming in on what counts as core and auxiliary: A case study on recognition models of visual working memory

Research on best practices in theory assessment highlights that testing theories is challenging because they inherit a new set of assumptions as soon as they are linked to a specific methodology. In this article, we integrate and build on this work by demonstrating the breadth of these challenges. We show that tracking auxiliary assumptions is difficult because they are made at different stages of theory testing and at multiple levels of a theory. We focus on these issues in a reanalysis of a seminal study and its replications, both of which use a simple working-memory paradigm and a mainstream computational modeling approach. These studies provide the main evidence for "all-or-none" recognition models of visual working memory and are still used as the basis for how to measure performance in popular visual working-memory tasks. In our reanalysis, we find that core practical auxiliary assumptions were unchecked and violated; the original model comparison metrics and data were not diagnostic in several experiments. Furthermore, we find that models were not matched on "theory general" auxiliary assumptions, meaning that the set of tested models was restricted, and not matched in theoretical scope. After testing these auxiliary assumptions and identifying diagnostic testing conditions, we find evidence for the opposite conclusion. That is, continuous resource models outperform all-or-none models. Together, our work demonstrates why tracking and testing auxiliary assumptions remains a fundamental challenge, even in prominent studies led by careful, computationally minded researchers. Our work also serves as a conceptual guide on how to identify and test the gamut of auxiliary assumptions in theory assessment, and we discuss these ideas in the context of contemporary approaches to scientific discovery.

Age-related differences in the relationship between confidence and false memory in a mnemonic discrimination task

In addition to episodic memory loss there is an increase in false remembering in ageing especially when the discrimination between studied and new items is difficult in a recognition memory task. The aim of this study was to identify the underlying psychological mechanisms of this behavior, specifically, the possible role of false recollection. We used the Mnemonic Similarity Task, a widely used task in neuroscience research developed to assess the behavioral manifestation of hippocampal computations, pattern separation and pattern completion. First, older and young adults (n = 39 and 44, respectively) were presented with images of everyday objects. Then, on a surprise recognition test, they saw old (studied) and new (non-studied) items as well as visually similar lures of the images seen in the study phase. Instead of using the original Old/New test format, we asked participants to make confidence judgments. Our response frequency and ROC (receiver operating characteristics) analyses revealed overconfidence in false memories for the lures in the group of older adults suggesting false recollection. Such overconfidence was not observed for the completely new stimuli. Our results imply that older adults tend not to acknowledge some memory problems as a consequence of very high confidence in false memories.

A neuronal code for object representation and memory in the human amygdala and hippocampus

How the brain encodes, recognizes, and memorizes general visual objects is a fundamental question in neuroscience. Here, we investigated the neural processes underlying visual object perception and memory by recording from 3173 single neurons in the human amygdala and hippocampus across four experiments. We employed both passive-viewing and recognition memory tasks involving a diverse range of naturalistic object stimuli. Our findings reveal a region-based feature code for general objects, where neurons exhibit receptive fields in the high-level visual feature space. This code can be validated by independent new stimuli and replicated across all experiments, including fixation-based analyses with large natural scenes. This region code explains the long-standing visual category selectivity, preferentially enhances memory of encoded stimuli, predicts memory performance, encodes image memorability, and exhibits intricate interplay with memory contexts. Together, region-based feature coding provides an important mechanism for visual object processing in the human brain.

Effect of levels-of-processing on rates of forgetting

The levels-of-processing (LOP) framework, proposing that deep processing yields superior retention, has provided an important paradigm for memory research and a practical means of improving learning. However, the available levels-of-processing literature focuses on immediate memory performance. It is assumed within the LOP framework that deep processing will lead to slower forgetting than will shallow processing. However, it is unclear whether, or how, the initial level of processing affects the forgetting slopes over longer retention intervals. The present three experiments were designed to explore whether items encoded at qualitatively different LOP are forgotten at different rates. In the first two experiments, depth of processing was manipulated within-participants at encoding under deep and shallow conditions (semantic vs. rhyme judgement in Experiment 1; semantic vs. consonant-vowel pattern decision in Experiment 2). Recognition accuracy (d prime) was measured between-participants immediately after learning and at 30-min, 2-h, and 24-h delays. The third experiment employed a between-participants design, contrasting the rates of forgetting following semantic and phonological (rhyme) processing at immediate, 30-min, 2-h, and 6-h delays. Results from the three experiments consistently demonstrated a large effect size of levels of processing on immediate performance and a medium-to-large level effect size on delayed recognition, but crucially no LOP × delay group interaction. Analysis of the retention curves revealed no significant differences between the slopes of forgetting for deep and shallow processing. These results suggest that the rates of forgetting are independent of the qualitatively distinct encoding operations manipulated by levels of processing.

Testing the dual-memory framework: individual differences in the magnitude of the retrieval practice effect and fluid intelligence

Retrieving information from memory enhances long-term retention. In this manuscript, we describe the dual-memory framework, which makes interval-scale predictions of the magnitude of this retrieval practice effect. After outlining the framework, we use data from our laboratory-both at the group level and at the distribution level-to fit the equations from the dual-memory framework. Overall, we successfully fitted the model predictions to the observed average data. In addition, we compared the predicted and the observed distributions of performance in the retrieval practice condition. More importantly, we introduce a useful approach to simulate empirical scenarios and test the relationship between individual-difference variables and the retrieval practice effect. We illustrate the application of this approach using data from a study that measured fluid intelligence. Future studies may benefit from contrasting different strength-based frameworks.

Context familiarity is a third kind of episodic memory distinct from item familiarity and recollection

Episodic memory is accounted for with two processes: "familiarity" when generally recognizing an item and "recollection" when retrieving the full contextual details bound with the item. We tested a combination of item recognition confidence and source memory, focusing upon three conditions: "item-only hits with source unknown" ('item familiarity'), "low-confidence hits with correct source memory" ('context familiarity'), and "high-confidence hits with correct source memory" ('recollection'). Behaviorally, context familiarity was slower than the others during item recognition, but faster during source memory. Electrophysiologically, a triple dissociation was evident in event-related potentials (ERPs), which was independently replicated. Context familiarity exhibited a negative effect from 800 to 1200 ms, differentiated from positive ERPs for item-familiarity (400-600 ms) and recollection (600-900 ms). These three conditions thus reflect mutually exclusive, fundamentally different processes of episodic memory, and we offer a new, tri-component model of memory. Context familiarity is a third distinct process of episodic memory.

Prior memory responses modulate behavior and brain state engagement

Memory encoding and retrieval constitute neurally dissociable brain states and prior behavioral work suggests that these states may linger in time. Thus memory states may influence both the current experience and subsequent events; however, this account has not been directly tested. To test the hypothesis that memory judgments induce brain states that persist for several hundred milliseconds, we recorded scalp electroencephalography while participants completed a recognition task. We used an independently validated multivariate mnemonic state classifier to assess memory state engagement. We replicate previous behavioral findings, yet we find that memory states are modulated by response congruency. We find strong retrieval state engagement on incongruent trials, when the response switches between two consecutive trials. These findings indicate that cortical brain states are influenced by prior judgments and suggest that a non-mnemonic, internal attention state may be recruited in the face of changing demands in a dynamic environment.

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.

Effects of left ventrolateral prefrontal stimulation on forming and maintaining deep and shallow episodic traces

The levels-of-processing framework, proposing that deep encoding enhances retention, plays a crucial role in episodic memory research. Neuroimaging evidence highlights that increased activity of the left ventrolateral prefrontal cortex during deep encoding predicts subsequent memory success. However, cognitive mechanisms underlying this region's involvement in establishing and consolidating deep and shallow traces remain unclear. In this preregistered study, we investigated whether repetitive transcranial magnetic stimulation over the left ventrolateral prefrontal cortex versus the vertex differentially modulates the formation and maintenance of deep and shallow traces. Trains of 20 Hz online repetitive transcranial magnetic stimulation were delivered over the left ventrolateral prefrontal cortex or vertex during tasks involving pleasantness (deep) and alphabetical order (shallow) judgments of words. Following encoding, two recognition tests assessed immediate and 24-h delayed recognition of words. Compared to the vertex control, ventrolateral prefrontal stimulation selectively disrupted the formation of episodic memory under deep encoding conditions, evidenced by increased response time at encoding and reduced immediate recognition in the deep but not shallow condition. Notably, forgetting rates across the 24-h delay were similar for disrupted deep, intact deep, and shallow items, implying that the rate of trace decay is independent of the strength of trace formation. The constant trace decay indicates that distinct mechanisms are involved in establishing and maintaining episodic traces.

Transitional gradation and the distinction between episodic and semantic memory

In this article, we explore various arguments against the traditional distinction between episodic and semantic memory based on the metaphysical phenomenon of transitional gradation. Transitional gradation occurs when two candidate kinds A and B grade into one another along a continuum according to their characteristic properties. We review two kinds of arguments-from the gradual semanticization of episodic memories as they are consolidated, and from the composition of episodic memories during storage and recall from semantic memories-that predict the proliferation of such transitional forms. We further explain why the distinction cannot be saved from the challenges of transitional gradation by appealing to distinct underlying memory structures and applying our perspective to the impasse over research into 'episodic-like' memory in non-human animals. On the whole, we recommend replacing the distinction with a dynamic life cycle of memory in which a variety of transitional forms will proliferate, and illustrate the utility of this perspective by tying together recent trends in animal episodic memory research and recommending productive future directions. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Episodic memory without autonoetic consciousness

Ever since Tulving's influential 1985 article 'Memory and consciousness', it has become traditional to think of autonoetic consciousness as necessary for episodic memory. This paper questions this claim. Specifically, it argues that the construct of autonoetic consciousness lacks validity and that, even if it was valid, it would still not be necessary for episodic memory. The paper ends with a proposal to go back to a functional/computational characterization of episodic memory in which its characteristic phenomenology is a contingent feature of the retrieval process and, as a result, open to empirical scrutiny. The proposal also dovetails with recent taxonomies of memory that are independent of conscious awareness and suggests strategies to evaluate within- and between-individual variability in the conscious experience of episodic memories in human and non-human agents. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

The influence of working memory mechanisms on false memories in immediate and delayed tests

There is growing evidence that false memories can occur in working memory (WM) tasks with only a few semantically related words and seconds between study and test. Abadie and Camos (2019) proposed a new model to explain the formation of false memories by describing the role of articulatory rehearsal and attentional refreshing, the two main mechanisms for actively maintaining information in WM. However, this model has only been tested in recognition tasks. In the present study, we report four experiments testing the model in recall tasks in which the active maintenance of information in WM plays a more important role for retrieval. Short lists of semantically related items were held for a short retention interval filled with a concurrent task that either impaired or not the use of each of the WM maintenance mechanisms. Participants were asked to recall the items immediately after the concurrent task (immediate test) or later, at the end of a block of several trials (delayed test). In the immediate test, semantic errors were more frequent when WM maintenance was impaired. Specifically, rehearsal prevented the occurrence of semantic errors in the immediate test, while refreshing had no effect on their occurrence in this test, but increased semantic errors produced only in the delayed test. These results support Abadie and Camos (2019) model and go further by demonstrating the role of active information maintenance in WM in the emergence of false memories. The implications of these findings for understanding WM-LTM relationships are discussed.

Working memory limitations constrain visual episodic long-term memory at both specific and gist levels of representation

Limitations in one's capacity to encode information in working memory (WM) constrain later access to that information in long-term memory (LTM). The present study examined whether these WM constraints on episodic LTM are limited to specific representations of past episodes or also extend to gist representations. Across three experiments, young adult participants (n = 40 per experiment) studied objects in set sizes of two or six items, either sequentially (Experiments 1a and 1b) or simultaneously (Experiment 2). They then completed old/new recognition tests immediately after each sequence (WM tests). After a long study phase, participants completed LTM conjoint recognition tests, featuring old but untested items from the WM phase, lures that were similar to studied items at gist but not specific levels of representation, and new items unrelated to studied items at both specific and gist levels of representation. Results showed that LTM estimates of specific and gist memory representations from a multinomial-processing-tree model were reduced for items encoded under supra-capacity set sizes (six items) relative to within-capacity set sizes (two items). These results suggest that WM encoding capacity limitations constrain episodic LTM at both specific and gist levels of representation, at least for visual objects. The ability to retrieve from LTM each type of representation for a visual item is contingent on the degree to which the item could be encoded in WM.

Improving the diagnostic value of lineup rejections

Erroneous eyewitness identification evidence is likely the leading cause of wrongful convictions. To minimize this error, scientists recommend collecting confidence. Research shows that eyewitness confidence and accuracy are strongly related when an eyewitness identifies someone from an initial and properly administered lineup. However, confidence is far less informative of accuracy when an eyewitness identifies no one and rejects the lineup instead. In this study, I aimed to improve the confidence-accuracy relationship for lineup rejections in two ways. First, I aimed to find the lineup that yields the strongest confidence-accuracy relationship for lineup rejections by comparing the standard, simultaneous procedure used by police worldwide to the novel "reveal" procedure designed by scientists to boost accuracy. Second, I aimed to find the best method for collecting confidence. To achieve this secondary aim, I made use of machine-learning techniques to compare confidence expressed in words to numeric confidence ratings. First, I find a significantly stronger confidence-accuracy relationship for lineup rejections in the reveal than in the standard procedure regardless of the method used to collect confidence. Second, I find that confidence expressed in words captures unique diagnostic information about the likely accuracy of a lineup rejection separate from the diagnostic information captured by numeric confidence ratings. These results inform models of recognition memory and may improve the criminal-legal system by increasing the diagnostic value of a lineup rejection.

Dissociable Contributions of Goal-Relevant Evidence and Goal-Irrelevant Familiarity to Individual and Developmental Differences in Conflict Recognition

Recent studies using the diffusion decision model find that performance across many cognitive control tasks can be largely attributed to a task-general efficiency of evidence accumulation (EEA) factor that reflects individuals' ability to selectively gather evidence relevant to task goals. However, estimates of EEA from an n-back "conflict recognition" paradigm in the Adolescent Brain Cognitive DevelopmentSM (ABCD) Study, a large, diverse sample of youth, appear to contradict these findings. EEA estimates from "lure" trials-which present stimuli that are familiar (i.e., presented previously) but do not meet formal criteria for being a target-show inconsistent relations with EEA estimates from other trials and display atypical v-shaped bivariate distributions, suggesting many individuals are responding based largely on stimulus familiarity rather than goal-relevant stimulus features. We present a new formal model of evidence integration in conflict recognition tasks that distinguishes individuals' EEA for goal-relevant evidence from their use of goal-irrelevant familiarity. We then investigate developmental, cognitive, and clinical correlates of these novel parameters. Parameters for EEA and goal-irrelevant familiarity-based processing showed strong correlations across levels of n-back load, suggesting they are task-general dimensions that influence individuals' performance regardless of working memory demands. Only EEA showed large, robust developmental differences in the ABCD sample and an independent age-diverse sample. EEA also exhibited higher test-retest reliability and uniquely meaningful associations with clinically relevant dimensions. These findings establish a principled modeling framework for characterizing conflict recognition mechanisms and have several broader implications for research on individual and developmental differences in cognitive control.

Not all objects are created equal: The object benefit in visual working memory is supported by greater recollection-like memory, but only for memorable objects

Visual working memory is thought to have a fixed capacity limit. However, recent evidence suggests that a greater number of real-world objects than simple features (i.e., colors) can be maintained, an effect termed the object benefit. Here, we examined whether this object benefit in visual working memory is due to qualitatively different memory processes employed for meaningful stimuli compared to simple features. In online samples of young adults, real-world objects were better remembered than colors, had higher measures of recollection, and showed a greater proportion of high-confidence responses (Exp. 1). Objects were also remembered better than their scrambled counterparts (Exp. 2), suggesting that this benefit is related to semantic information, rather than visual complexity. Critically, the specific objects that were likely to be remembered with high confidence were highly correlated across experiments, consistent with the idea that some objects are more memorable than others. Visual working memory performance for the least-memorable objects was worse than that of colors and scrambled objects. These findings suggest that real-world objects give rise to recollective, or at least high-confidence, responses at retrieval that may depend on activation of semantic features, but that this effect is limited to certain objects.

Recollective and non-recollective processes in working memory retrieval

The aim of this study was to investigate the nature of the processes involved in working memory (WM) retrieval by distinguishing between recollective (direct access) and non-recollective (reconstruction) recall. To this end, the trichotomous theory of recall (Brainerd et al., 2009) was applied to young adults' recall performance in a complex span task in which word lists were presented in three successive study-test trials. In three experiments, factors known to affect WM performance were manipulated, such as the cognitive load (CL) of the concurrent task and the involvement of long-term memory (LTM) knowledge through the associative relatedness of the memory items and the temporally spaced presentation of memory lists. The application of the trichotomous theory of recall proved effective and established that both recollective and non-recollective processes support WM recall, though recollective processes are predominant. The detrimental effect of increased CL on recall performance appeared to result from a reduction in direct access, while leaving reconstruction unaffected. Two manipulations aimed at increasing the involvement of LTM in recall had different effects on retrieval processes. Associative relatedness favored direct access, while spaced presentation reduced it. The implications of these findings for our understanding of the relationships between LTM and WM and for WM theories are discussed.

A third kind of episodic memory: Context familiarity is distinct from item familiarity and recollection

Episodic memory is accounted for with two processes: 'familiarity' when generally recognizing an item and 'recollection' when retrieving the full contextual details bound with the item. Paradoxically, people sometimes report contextual information as familiar but without recollecting details, which is not easily accounted for by existing theories. We tested a combination of item recognition confidence and source memory, focusing upon 'item-only hits with source unknown' ('item familiarity'), 'low-confidence hits with correct source memory' ('context familiarity'), and 'high-confidence hits with correct source memory' ('recollection'). Results across multiple within-subjects (trial-wise) and between subjects (individual variability) levels indicated these were behaviorally and physiologically distinct. Behaviorally, a crossover interaction was evident in response times, with context familiarity being slower than each condition during item recognition, but faster during source memory. Electrophysiologically, a Condition x Time x Location triple dissociation was evident in event-related potentials (ERPs), which was then independently replicated. Context familiarity exhibited an independent negative central effect from 800-1200 ms, differentiated from positive ERPs for item-familiarity (400 to 600 ms) and recollection (600 to 900 ms). These three conditions thus reflect mutually exclusive, fundamentally different processes of episodic memory. Context familiarity is a third distinct process of episodic memory.

Summary

Memory for past events is widely believed to operate through two different processes: one called 'recollection' when retrieving confident, specific details of a memory, and another called 'familiarity' when only having an unsure but conscious awareness that an item was experienced before. When people successfully retrieve details such as the source or context of a prior event, it has been assumed to reflect recollection. We demonstrate that familiarity of context is functionally distinct from familiarity of items and recollection and offer a new, tri-component model of memory. The three memory responses were differentiated across multiple behavioral and brain wave measures. What has traditionally been thought to be two kinds of memory processes are actually three, becoming evident when using sensitive enough multi-measures. Results are independently replicated across studies from different labs. These data reveal that context familiarity is a third process of human episodic memory.

The retrograde effects of negative emotion on memory for conceptually related events: a registered report

Emotional events are often remembered better than neutral ones; however, emotion can also spill over and affect our memory for neutral experiences that precede an emotional event. Theories suggest that emotion can retroactively enhance memory for preceding neutral events that are considered high-priority while impairing memory for events deemed low-priority. However, the impact of conceptual relationships (i.e., semantic connections) between preceding neutral information and emotional events on memory for the preceding information has received little attention. This study investigated the influence of conceptual relatedness on the retroactive effects of emotion on memory. Participants sequentially encoded pairs of images that were high or low in conceptual relatedness, each comprising a neutral object followed by either a negative or neutral image. Participants returned the next day for a recognition memory assessment. The results indicated an interactive effect of emotion and conceptual relatedness on memory: In a "discovery" sample, memory was poorer for images preceding conceptually unrelated negative (vs. neutral) images, while the opposite pattern was seen for conceptually related images. In a "replication" sample, these effects were partially replicated, with the former impairment effect statistically observed but not the latter augmentation effect. Hence, conceptual relatedness affects how negative emotion influences memory.

Are autistic traits associated with a social-emotional memory bias?

Autistic traits are associated with differential processing of emotional and social cues. By contrast little is known about the relationship of autistic traits to socio-emotional memory, though research suggests an integral relationship between episodic memory processes and psychosocial well-being. Using an experimental paradigm, we tested if autistic traits moderate the effects of negative emotion and social cues on episodic memory (i.e. memory for past events). Young adults (N = 706) with varied levels of self-reported autistic traits (24% in clinical range) encoded images stratified by emotion (negative, neutral) and social cues (social, non-social) alongside a neutral object. After 24 h, item memory for images and associative memory for objects was tested. For item memory, after controlling for anxiety, a small effect emerged whereby a memory-enhancing effect of social cues was reduced as autistic traits increased. For associative memory, memory for pairings between neutral, but not negative, images reduced as autistic traits increased. Results suggest autistic traits are associated with reduced ability to bind neutral items together in memory, potentially impeding nuanced appraisals of past experience. This bias toward more negative, less nuanced memories of past experience may represent a cognitive vulnerability to social and mental health challenges commonly associated with autistic traits and a potential intervention target.

The late positive event-related potential component is time locked to the decision in recognition memory tasks

Two event-related potential (ERP) components are commonly observed in recognition memory tasks: the Frontal Negativity (FN400) and the Late Positive Component (LPC). These components are widely interpreted as neural correlates of familiarity and recollection, respectively. However, the interpretation of LPC effects is complicated by inconsistent results regarding the timing of ERP amplitude differences. There are also mixed findings regarding how LPC amplitudes covary with decision confidence. Critically, LPC effects have almost always been measured using fixed time windows relative to memory probe stimulus onset, yet it has not been determined whether LPC effects are time locked to the stimulus or the recognition memory decision. To investigate this, we analysed a large (n = 132) existing dataset recorded during recognition memory tasks with old/new decisions followed by post-decisional confidence ratings. We used ERP deconvolution to disentangle contributions to LPC effects (defined as differences between hits and correct rejections) that were time locked to either the stimulus or the vocal old/new response. We identified a left-lateralised parietal LPC effect that was time locked to the vocal response rather than probe stimulus onset. We also isolated a response-locked, midline parietal ERP correlate of confidence that influenced measures of LPC amplitudes at left parietal electrodes. Our findings demonstrate that, contrary to widespread assumptions, the LPC effect is time locked to the recognition memory decision and is best measured using response-locked ERPs. By extension, differences in response time distributions across conditions of interest may lead to substantial measurement biases when analysing stimulus-locked ERPs. Our findings highlight important confounding factors that further complicate the interpretation of existing stimulus-locked LPC effects as neural correlates of recollection. We recommend that future studies adopt our analytic approach to better isolate LPC effects and their sensitivity to manipulations in recognition memory tasks.

Process approach as a cognitive biomarker related to gray matter volume in mild cognitive impairment and Alzheimer's disease

BACKGROUND

Process approach is valuable for memory assessment in Alzheimer's disease (AD) and mild cognitive impairment (MCI), yet its underlying mechanisms remain elusive. This study aims to synergize the process approach with brain structure analysis to explore both the discriminative capacity and potential mechanisms underlying the process approach.

METHODS

37 subjects of MCI, 35 subjects of AD and 38 subjects of healthy control (HC) were included. The process approach in Auditory Verbal Learning Test (AVLT), including discriminability (A'), response bias (B"D), semantic clustering (LBCsem) and serial clustering (LBCser) was performed. The gray matter volume (GMV) was analyzed by voxel-based morphometry. Receiver operating characteristic (ROC) analysis and partial correlations were conducted to explore the value of the process approach and investigate the relationship between the process approach, traditional indices of AVLT and GMV.

RESULTS

ROC analysis showed the value of A', B"D and LBCser in differentiating MCI and AD. Combining AVLT-Immediately Recall (AVLT-IR) and LBCser showed a higher value in diagnosing MCI. Partial correlations revealed that in the MCI group, A' and B"D were mainly positively associated with GMV of the hippocampus and temporal lobe.

CONCLUSION

This study indicated that the process approach is a promising cognitive biomarker to detect MCI and AD.

Response-locked theta dissociations reveal potential feedback signal following successful retrieval

Successful memory retrieval relies on memory processes to access an internal representation and decision processes to evaluate and respond to the accessed representation, both of which are supported by fluctuations in theta (4-8 Hz) activity. However, the extent to which decision-making processes are engaged following a memory response is unclear. Here, we recorded scalp electroencephalography (EEG) while human participants performed a recognition memory task. We focused on response-locked data, allowing us to investigate the processes that occur prior to and following a memory response. We replicate previous work and find that prior to a memory response theta power is greater for identification of previously studied items (hits) relative to rejection of novel lures (correct rejections; CRs). Following the memory response, the theta power dissociation "flips" whereby theta power is greater for CRs relative to hits. We find that the post-response "flip" is more robust for hits that are committed quickly, potentially reflecting a positive feedback signal for strongly remembered experiences. Our findings suggest that there are potentially distinct processes occurring before and after a memory response that are modulated by successful memory retrieval.

The attentional boost effect in free recall dynamics

With the attentional boost effect (ABE), responding to a briefly presented target in a detection task enhances the encoding of other items presented at the same time. However, the effects of target detection on context memory for the event in which the stimulus appeared remain unclear. Here, we present findings from verbal free recall and recognition experiments that test the effects of target detection during encoding on temporal and relational aspects of context memory. Consistent with prior demonstrations of limited effects of target detection on context memory, in Experiment 1 there was no evidence that target detection influenced the likelihood of transitioning to items that were presented at similar times during encoding, or that were in the same encoding condition. These null effects were replicated in a second experiment, which added an old/new recognition and relational memory test. These results indicate that target detection during encoding has minimal effects on the formation of temporal associations between words in memory.

The persistence of memory: prior memory responses modulate behavior and brain state engagement

Memory brain states may influence how we experience an event. Memory encoding and retrieval constitute neurally dissociable brain states that individuals can selectively engage based on top-down goals. To the extent that memory states linger in time - as suggested by prior behavioral work - memory states may influence not only the current experience, but also subsequent stimuli and judgments. Thus lingering memory states may have broad influences on cognition, yet this account has not been directly tested utilizing neural measures of memory states. Here we address this gap by testing the hypothesis that memory brain states are modulated by memory judgments, and that these brain states persist for several hundred milliseconds. We recorded scalp electroencephalography (EEG) while participants completed a recognition memory task. We used an independently validated multivariate mnemonic state classifier to assess memory state engagement. We replicate prior behavioral findings; however, our neural findings run counter to the predictions made on the basis of the behavioral data. Surprisingly, we find that prior responses modulate current memory state engagement on the basis of response congruency. That is, we find strong engagement of the retrieval state on incongruent trials - when a target is preceded by a correct rejection of a lure and when a lure is preceded by successful recognition of a target. These findings indicate that cortical brain states are influenced by prior judgments and suggest that a non-mnemonic, internal attention state may be recruited to in the face of changing demands in a dynamic environment.

Greater target or lure variability? An exploration on the effects of stimulus types and memory paradigms

In recognition memory, the variance of the target distribution is almost universally found to be greater than that of the lure distribution. However, these estimates commonly come from long-term memory paradigms where words are used as stimuli. Two exceptions to this rule have found evidence for greater lure variability: a short-term memory task (Yotsumoto et al., Memory & Cognition, 36, 282-294 2008) and in an eyewitness memory paradigm (Wixted et al., Cognitive Psychology, 105, 81-114 2018). In the present work, we conducted a series of recognition memory experiments using different stimulus (faces vs. words) along with different paradigms (long-term vs. short-term paradigms) to evaluate whether either of these conditions would result in greater variability in lure items. Greater target variability was observed across stimulus types and memory paradigms. This suggests that factors other than stimuli and retention interval might be responsible for cases where variability is less for targets than lures.

Specificity and sensitivity of the fixed-point test for binary mixture distributions

When two cognitive processes contribute to a behavioral output-each process producing a specific distribution of the behavioral variable of interest-and when the mixture proportion of these two processes varies as a function of an experimental condition, a common density point should be present in the observed distributions of the data across said conditions. In principle, one can statistically test for the presence (or absence) of a fixed point in experimental data to provide evidence in favor of (or against) the presence of a mixture of processes, whose proportions are affected by an experimental manipulation. In this paper, we provide an empirical diagnostic of this test to detect a mixture of processes. We do so using resampling of real experimental data under different scenarios, which mimic variations in the experimental design suspected to affect the sensitivity and specificity of the fixed-point test (i.e., mixture proportion, time on task, and sample size). Resampling such scenarios with real data allows us to preserve important features of data which are typically observed in real experiments while maintaining tight control over the properties of the resampled scenarios. This is of particular relevance considering such stringent assumptions underlying the fixed-point test. With this paper, we ultimately aim at validating the fixed-point property of binary mixture data and at providing some performance metrics to researchers aiming at testing the fixed-point property on their experimental data.

Recognition memory: The probe, the returned signal, and the decision

In an attempt to better understand recognition memory we look at how three approaches (dual processing, signal detection, and global matching) have addressed the probe, the returned signal and the decision in four recognition paradigms. These are single-item recognition (including the remember/know paradigm), recognition in relational context, associative recognition, and source monitoring. The contrast, with regards to the double-miss rate (the probability of recognizing neither item in intact and rearranged pairs) and the effect of the oldness of the other member of the test pair, between identifying the old words in test pairs (the relational context paradigm) and first identifying the intact test pairs and then identifying the old words (adding associative recognition to the relational context paradigm) suggests that the retrieval of associative information in the relational context paradigm is unintentional, unlike the retrieval of associative information in associative recognition. It also seems possible that the information that is spontaneously retrieved in single-item recognition, possibly including the remember/know paradigm, is also unintentional, unlike the retrieval of information in source monitoring. Probable differences between intentional and unintentional retrieval, together with the pattern of effects with regards to the double-miss rate and the effect of the other member of the test pair, are used to evaluate the three approaches. Our conclusion is that all three approaches have something valid to say about recognition, but none is equally applicable across all four paradigms.

Divergent thinking modulates interactions between episodic memory and schema knowledge: Controlled and spontaneous episodic retrieval processes

The ability to generate novel ideas, known as divergent thinking, depends on both semantic knowledge and episodic memory. Semantic knowledge and episodic memory are known to interact to support memory decisions, but how they may interact to support divergent thinking is unknown. Moreover, it is debated whether divergent thinking relies on spontaneous or controlled retrieval processes. We addressed these questions by examining whether divergent thinking ability relates to interactions between semantic knowledge and different episodic memory processes. Participants completed the alternate uses task of divergent thinking, and completed a memory task in which they searched for target objects in schema-congruent or schema-incongruent locations within scenes. In a subsequent test, participants indicated where in each scene the target object had been located previously (i.e., spatial accuracy test), and provided confidence-based recognition memory judgments that indexed distinct episodic memory processes (i.e., recollection, familiarity, and unconscious memory) for the scenes. We found that higher divergent thinking ability-specifically in terms of the number of ideas generated-was related to (1) more of a benefit from recollection (a controlled process) and unconscious memory (a spontaneous process) on spatial accuracy and (2) beneficial differences in how semantic knowledge was combined with recollection and unconscious memory to influence spatial accuracy. In contrast, there were no effects with respect to familiarity (a spontaneous process). These findings indicate that divergent thinking is related to both controlled and spontaneous memory processes, and suggest that divergent thinking is related to the ability to flexibly combine semantic knowledge with episodic memory.

Comparing episodic memory outcomes from walking augmented reality and stationary virtual reality encoding experiences

Episodic Memory (EM) is the neurocognitive capacity to consciously recollect personally experienced events in specific spatio-temporal contexts. Although the relevance of spatial and temporal information is widely acknowledged in the EM literature, it remains unclear whether and how EM performance and organisation is modulated by self-motion, and by motor- and visually- salient environmental features (EFs) of the encoding environment. This study examines whether and how EM is modulated by locomotion and the EFs encountered in a controlled lifelike learning route within a large-scale building. Twenty-eight healthy participants took part in a museum-tour encoding task implemented in walking Augmented Reality (AR) and stationary Virtual Reality (VR) conditions. EM performance and organisation were assessed immediately and 48-hours after trials using a Remember/Familiar recognition paradigm. Results showed a significant positive modulation effect of locomotion on distinctive EM aspects. Findings highlighted a significant performance enhancement effect of stairway-adjacent locations compared to dead-end and mid-route stimuli-presentation locations. The results of this study may serve as design criteria to facilitate neurocognitive rehabilitative interventions of EM. The underlying technological framework developed for this study represents a novel and ecologically sound method for evaluating EM processes in lifelike situations, allowing researchers a naturalistic perspective into the complex nature of EM.

Retrieving effectively from source memory: Evidence for differentiation and local matching processes

The ability to distinguish between different explanations of human memory abilities continues to be the subject of many ongoing theoretical debates. These debates attempt to account for a growing corpus of empirical phenomena in item-memory judgments, which include the list strength effect, the strength-based mirror effect, and output interference. One of the main theoretical contenders is the Retrieving Effectively from Memory (REM) model. We show that REM, in its current form, has difficulties in accounting for source-memory judgments - a situation that calls for its revision. We propose an extended REM model that assumes a local-matching process for source judgments alongside source differentiation. We report a first evaluation of this model's predictions using three experiments in which we manipulated the relative source-memory strength of different lists of items. Analogous to item-memory judgments, we observed a null list strength effect and a strength-based mirror effect in the case of source memory. In a second evaluation, which relied on a novel experiment alongside two previously published datasets, we evaluated the model's predictions regarding the manifestation of output interference in item and lack of it in source memory judgments. Our results showed output interference severely affecting the accuracy of item-memory judgments but having a null or negligible impact when it comes to source-memory judgments. Altogether, these results support REM's core notion of differentiation (for both item and source information) as well as the concept of local matching proposed by the present extension.

The role of mediators for the pretesting effect

Taking a pretest (e.g., smoke - ?) before material is studied (smoke - fog) can improve later recall of that material, compared to material which was initially only studied. The goal of the present study was to evaluate for this pretesting effect the potential role of semantic mediators, i.e., of unstudied information that is semantically related to the study material. In all three experiments, subjects studied weakly associated word pairs (e.g., smoke - fog), half of which received a pretest. Subjects then either completed a recognition test (Experiment 1) or a cued-recall test (Experiments 2 and 3), during which they were presented with both the original study material and never-before-seen semantic mediators that were strongly related to the cue item of a pair (e.g., cigarette). Strikingly, presenting semantic mediators as lures led to higher false alarm rates for mediators following initial pretesting than study only (Experiment 1), and presenting semantic mediators as retrieval cues led to better recall of target items following pretesting than study only (Experiments 2 and 3). We argue that these findings support the elaboration account of the pretesting effect but are difficult to reconcile with other prominent accounts of the effect.

Functional and anatomical connectivity predict brain stimulation's mnemonic effects

Closed-loop direct brain stimulation is a promising tool for modulating neural activity and behavior. However, it remains unclear how to optimally target stimulation to modulate brain activity in particular brain networks that underlie particular cognitive functions. Here, we test the hypothesis that stimulation's behavioral and physiological effects depend on the stimulation target's anatomical and functional network properties. We delivered closed-loop stimulation as 47 neurosurgical patients studied and recalled word lists. Multivariate classifiers, trained to predict momentary lapses in memory function, triggered the stimulation of the lateral temporal cortex (LTC) during the study phase of the task. We found that LTC stimulation specifically improved memory when delivered to targets near white matter pathways. Memory improvement was largest for targets near white matter that also showed high functional connectivity to the brain's memory network. These targets also reduced low-frequency activity in this network, an established marker of successful memory encoding. These data reveal how anatomical and functional networks mediate stimulation's behavioral and physiological effects, provide further evidence that closed-loop LTC stimulation can improve episodic memory, and suggest a method for optimizing neuromodulation through improved stimulation targeting.

Response-locked theta dissociations reveal potential feedback signal following successful retrieval

Successful memory retrieval relies on memory processes to access an internal representation and decision processes to evaluate and respond to the accessed representation, both of which are supported by fluctuations in theta (4-8Hz) activity. However, the extent to which decision making processes are engaged following a memory response is unclear. Here, we recorded scalp electroencephalography (EEG) while human participants performed a recognition memory task. We focused on response-locked data, allowing us to investigate the processes that occur prior to and following a memory response. We replicate previous work and find that prior to a memory response theta power is greater for identification of previously studied items (hits) relative to rejection of novel lures (correct rejections; CRs). Following the memory response, the theta power dissociation 'flips' whereby theta power is greater for CRs relative to hits. We find that the post-response 'flip' is more robust for hits that are committed quickly, potentially reflecting a positive feedback signal for strongly remembered experiences. Our findings suggest that there are potentially distinct processes occurring before and after a memory response that are modulated by successful memory retrieval.

The role of metacognitive uncertainty in the delayed retrieval shift of older adults

Strategic choice behavior of older adults in many skill acquisition tasks can be characterized as a delayed and/or incomplete shift to a more efficient retrieval-based strategy, even when older adults possess the requisite knowledge to use it successfully. The noun-pair lookup task (NPLT) requires verification of whether a centrally presented word pair matches one of a set of pairs displayed at the top of the screen. Because the pairings do not change, verification can be made from memory as the associations are learned. This study examines the role of metacognitive uncertainty in explaining older adults' delayed retrieval shift in the NPLT. Older and younger adults participated in a NPLT with previously learned items and new items. For each trial, the look-up table was shown only if the scanning strategy was selected. Some participants were given a precue informing whether the item had been previously learned. Retrieval strategy choice was low for older adults but precueing increased its frequency. Older adults' retrieval choices had minimal costs on NPLT accuracy, suggesting that the delayed retrieval shift can be exacerbated by metacognitive uncertainty that was reduced by precueing. The role of metacognitive uncertainty in older adults' retrieval avoidance was supported by a robust item-level regression effect of retrospective confidence judgments during prelearning tests and later NPLT retrieval strategy choices for older adults.

How do people build up visual memory representations from sensory evidence? Revisiting two classic models of choice

In many decision tasks, we have a set of alternative choices and are faced with the problem of how to use our latent beliefs and preferences about each alternative to make a single choice. Cognitive and decision models typically presume that beliefs and preferences are distilled to a scalar latent strength for each alternative, but it is also critical to model how people use these latent strengths to choose a single alternative. Most models follow one of two traditions to establish this link. Modern psychophysics and memory researchers make use of signal detection theory, assuming that latent strengths are perturbed by noise, and the highest resulting signal is selected. By contrast, many modern decision theoretic modeling and machine learning approaches use the softmax function (which is based on Luce's choice axiom; Luce, 1959) to give some weight to non-maximal-strength alternatives. Despite the prominence of these two theories of choice, current approaches rarely address the connection between them, and the choice of one or the other appears more motivated by the tradition in the relevant literature than by theoretical or empirical reasons to prefer one theory to the other. The goal of the current work is to revisit this topic by elucidating which of these two models provides a better characterization of latent processes in m -alternative decision tasks, with a particular focus on memory tasks. In a set of visual memory experiments, we show that, within the same experimental design, the softmax parameter β varies across m -alternatives, whereas the parameterd ' of the signal-detection model is stable. Together, our findings indicate that replacing softmax with signal-detection link models would yield more generalizable predictions across changes in task structure. More ambitiously, the invariance of signal detection model parameters across different tasks suggests that the parametric assumptions of these models may be more than just a mathematical convenience, but reflect something real about human decision-making.

Illustrations of interactions needed when investigating sleep using a type of AM-PM PM-AM design

Sleep has long been thought of and promoted to be beneficial for memory. Some claims that sleep aids memory have been made in the absence of a critical interaction. This condition is necessary when using a commonly-used experimental design (a type of AM-PM PM-AM design). We propose that a sleep effect exists only if there is an interaction between groups (experimental and time-of-day controls) and the time of test or study (morning and evening). We show different patterns of results that would and would not support a sleep effect with empirical and model-generated data from recognition memory experiments and hypothetical data. While we use these data to make our point, our suggestions apply to any memory and non-memory-related investigation (e.g., emotional memory, false memory susceptibility, language learning, problem-solving). Testing for and finding the proper interaction will add to the evidence that sleep boosts performance.

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.

Memory error speed predicts subsequent accuracy for recognition misses but not false alarms

The current study aims to test whether faster recognition memory errors tend to result from stronger misleading retrieval, making them harder to correct in subsequent decisions than slower errors, and whether this pattern holds for both miss and false-alarm errors. We used a paradigm in which each single-item Old/New recognition decision was followed by a two-alternative forced-choice (2AFC) test between a target and a lure. Each 2AFC trial had one item that had just been tested for an Old/New judgment and one item that had not been previously tested. Across 183 participants, the RTs for single-item recognition errors were used to predict accuracy in the 2AFC test using a hierarchical logistic regression model. The results showed a relationship between error RT and subsequent 2AFC accuracy that was qualified by an interaction with error type. Slower miss responses were more likely to be corrected than faster misses, but no accuracy differences were observed between slower and faster false alarms. The implications of these findings are discussed as they relate to assumptions about memory processes underlying inaccurate retrieval, using the diffusion model and the two-high-threshold model as examples of accounts that explain errors in terms of misleading retrieval and failed retrieval, respectively.

Widespread frontoparietal fMRI activity is greatly affected by changes in criterion placement, not discriminability, during recognition memory and visual detection tests

Widespread frontoparietal activity is consistently observed in recognition memory tests that compare studied ("target") versus unstudied ("nontarget") responses. However, there are conflicting accounts that ascribe various aspects of frontoparietal activity to mnemonic evidence versus decisional processes. According to Signal Detection Theory, recognition judgments require individuals to decide whether the memory strength of an item exceeds an evidence threshold-the decision criterion-for reporting previously studied items. Yet, most fMRI studies fail to manipulate both memory strength and decision criteria, making it difficult to appropriately identify frontoparietal activity associated with each process. In the current experiment, we manipulated both discriminability and decision criteria across recognition memory and visual detection tests during fMRI scanning to assess how frontoparietal activity is affected by each manipulation. Our findings revealed that maintaining a conservative versus liberal decision criterion drastically affects frontoparietal activity in target versus nontarget response contrasts for both recognition memory and visual detection tests. However, manipulations of discriminability showed virtually no differences in frontoparietal activity in target versus nontarget response or item contrasts. Comparing across task domains, we observed similar modulations of frontoparietal activity across criterion conditions, though the recognition memory task revealed larger activations in both magnitude and spatial extent in these contrasts. Nonetheless, there appears to be some domain specificity in frontoparietal activity associated with the maintenance of a conservative versus liberal criterion. We propose that widespread frontoparietal activity observed in target versus nontarget contrasts is largely attributable to response bias where increased activity may reflect inhibition of a prepotent response, which differs depending on whether a person maintains a conservative versus liberal decision criterion.

Does variability in recognition memory scale with mean memory strength or encoding variability in the UVSD model?

The unequal variance signal detection (UVSD) model of recognition memory assumes that the variance of old item memory strength (σo) is typically greater than that of new items. It has been suggested that this old item variance effect can be explained by the encoding variability hypothesis. However, Spanton and Berry (2020) failed to find evidence for this account, suggesting that σo may simply scale with mean memory strength (d) in the UVSD model. Experiments 1 and 2 examined the effects of encoding variability and strength scaling on old item variance by creating conditions in which mean memory strength and variability in item characteristics was either low or high in 2 × 2 factorial designs. In Experiment 1, overall strength determined estimates of σo, with no effect of item characteristic variability. The same effect of overall strength was found in Experiment 2; there was also a significant effect of item characteristic variability, although this manipulation also had some effect on d and was therefore partially confounded. Experiment 3 similarly found a simultaneous increase in old item variance and memory strength in a design using mixed item characteristic variability conditions in a single-study/test block. We conclude that old item variance increases with mean memory strength in the UVSD model, with uncertainty about the effects of encoding variability, and that future explanations of the old item variance effect should bear this in mind.

Cognitive perspectives on maintaining physicians' medical expertise: III. Strengths and weaknesses of self-assessment

Is self-assessment enough to keep physicians' cognitive skills-such as diagnosis, treatment, basic biological knowledge, and communicative skills-current? We review the cognitive strengths and weaknesses of self-assessment in the context of maintaining medical expertise. Cognitive science supports the importance of accurately self-assessing one's own skills and abilities, and we review several ways such accuracy can be quantified. However, our review also indicates a broad challenge in self-assessment is that individuals do not have direct access to the strength or quality of their knowledge and instead must infer this from heuristic strategies. These heuristics are reasonably accurate in many circumstances, but they also suffer from systematic biases. For example, information that feels easy to process in the moment can lead individuals to overconfidence in their ability to remember it in the future. Another notable phenomenon is the Dunning-Kruger effect: the poorest performers in a domain are also the least accurate in self-assessment. Further, explicit instruction is not always sufficient to remove these biases. We discuss what these findings imply about when physicians' self-assessment can be useful and when it may be valuable to supplement with outside sources.

Functional and anatomical connectivity predict brain stimulation's mnemonic effects

Closed-loop direct brain stimulation is a promising tool for modulating neural activity and behavior. However, it remains unclear how to optimally target stimulation to modulate brain activity in particular brain networks that underlie particular cognitive functions. Here, we test the hypothesis that stimulation's behavioral and physiological effects depend on the stimulation target's anatomical and functional network properties. We delivered closed-loop stimulation as 47 neurosurgical patients studied and recalled word lists. Multivariate classifiers, trained to predict momentary lapses in memory function, triggered stimulation of the lateral temporal cortex (LTC) during the study phase of the task. We found that LTC stimulation specifically improved memory when delivered to targets near white matter pathways. Memory improvement was largest for targets near white matter that also showed high functional connectivity to the brain's memory network. These targets also reduced low-frequency activity in this network, an established marker of successful memory encoding. These data reveal how anatomical and functional networks mediate stimulation's behavioral and physiological effects, provide further evidence that closed-loop LTC stimulation can improve episodic memory, and suggest a method for optimizing neuromodulation through improved stimulation targeting.

d o ′ : Sensitivity at the optimal criterion location

Signal detection theory (SDT) was developed to provide a measure of the discriminability of a signal against background noise, independently of response bias. However, equal discriminability over a range of bias is only achieved by the traditional signal detection measure d′ under a narrow set of conditions - i.e., binormal noise and signal distributions of equal variance and base rates. In response to observed departures from these conditions, more robust alternative measures of d′ have been developed, including da and, more recently, dp ′ . Each of these alternatives addresses some, but not all, of the difficulties that arise when the assumptions of SDT are violated. Moreover, none of these measures directly follow from a central idea of discriminability by an observer that adopts a minimize error count (MEC) strategy. I propose a new d′ alternative, do ′ , that is robust to violations of the standard signal detection assumptions, remains consistent with varying bias, and is grounded in the principle of discriminability following a MEC strategy. Simulations illustrate how do ′ is similar to the recently developed dp ′ when the observer optimizes their criterion placement to minimize the number of errors but, unlike dp ′ , remains consistent irrespective of the observer's criterion placement Moreover, unlike da, do ′ reflects changes in discriminability related to base rates of signal vs. noise presentations. The use of do ′ also has implications for the interpretation of bias metrics, such as β and c, which are examined at the optimal criterion under a variety of conditions.

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.

Prior experience modifies acquisition trajectories via response-strategy sampling

Few studies have considered how signal detection parameters evolve during acquisition periods. We addressed this gap by training mice with differential prior experience in a conditional discrimination, auditory signal detection task. Naïve mice, mice given separate experience with each of the later correct choice options (Correct Choice Response Transfer, CCRT), and mice experienced in conditional discriminations (Conditional Discrimination Transfer, CDT) were trained to detect the presence or absence of a tone in white noise. We analyzed data assuming a two-period model of acquisition: a pre-solution and solution period (Heinemann EG (1983) in The Presolution period and the detection of statistical associations. In: Quantitative analyses of behavior: discrimination processes, vol. 4, pp. 21-36). Ballinger. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.536.1978andrep=rep1andtype=pdf ). The pre-solution period was characterized by a selective sampling of biased response strategies until adoption of a conditional responding strategy in the solution period. Correspondingly, discriminability remained low until the solution period; criterion took excursions reflecting response-strategy sampling. Prior experience affected the length and composition of the pre-solution period. Whereas CCRT and CDT mice had shorter pre-solution periods than naïve mice, CDT and Naïve mice developed substantial criterion biases and acquired asymptotic discriminability faster than CCRT mice. To explain these data, we propose a learning model in which mice selectively sample and test different response-strategies and corresponding task structures until they exit the pre-solution period. Upon exit, mice adopt the conditional responding strategy and task structure, with action values updated via inference and generalization from the other task structures. Simulations of representative mouse data illustrate the viability of this model.