Responsible remembering: The role of metacognition, forgetting, attention, and retrieval in adaptive memory.

In our everyday lives, we must remember important information, especially if there are consequences for forgetting. In this review, I discuss recent work on responsible remembering: the strategic and effortful prioritization of important information with consequences for forgetting. Thus far, research regarding responsible remembering has revealed several key factors and mechanisms that work together to enhance memory for important information that will continue to be refined: the identification and selection of what to remember (metacognitive reflectivity), the forgetting of less important information to facilitate memory for items that do need to be remembered (responsible forgetting), the functional prioritization of attention at the expense of competing factors (responsible attention), and the selective recall of important information via efficient retrieval strategies (responsible retrieval). Together, these functions form a cohesive system that aims to selectively prioritize, encode, and recall information that is deemed important based on its anticipated utility or the consequences of forgetting, and considering the importance of information may be a critical memory adaptation as we age. Specifically, if younger and older adults learn to self-assess and prioritize important information that has negative consequences if forgotten, engage in strategic forgetting, efficiently allocate their attentional resources, and utilize effective retrieval operations, memory for said important information can be enhanced.

The disconnect between metamemory and memory for emotional images.

Emotional information is reliably predicted to be remembered better than neutral information, and this has been found for words, images, and facial expressions. However, many studies find that these judgments of learning (JOLs) are not predictive of memory performance (e.g. [Hourihan, K. L. (2020). Misleading emotions: Judgments of learning overestimate recognition of negative and positive emotional images. Cognition and Emotion, 34(4), 771-782. https://doi.org/10.1080/02699931.2019.1682972]). The present study investigates and rules out numerous potential causes for this discrepancy between memory predictions and performance, including (1) reactivity to making JOLs, (2) idiosyncrasies of specific images used, (3), type of memory test, and (4) effects of fluency. Three additional experiments investigate whether JOLs can become more predictive of memory performance, either by experience with the task or by manipulating prior beliefs about memory for emotional images. In all experiments, we found the same effect: Emotional images are inaccurately predicted to be remembered better than neutral images. The results suggest that emotion is used as a heuristic for learning, resulting in low metamnemonic accuracy for emotional stimuli.

Comparing human evaluations of eyewitness statements to a machine learning classifier under pristine and suboptimal lineup administration procedures.

Recent work highlights the ability of verbal machine learning classifiers to distinguish between accurate and inaccurate recognition memory decisions (Dobbins, 2022; Dobbins & Kantner, 2019; Seale-Carlisle, Grabman, & Dodson, 2022). Given the surge of interest in these modeling techniques, there is an urgent need to investigate verbal classifiers' limitations - particularly in applied contexts such as when police collect eyewitness's confidence statements. We find that confirmatory feedback (e.g., "This study now has a total of 87 participants, 84 of them made the same decision as you!") weakens the relationship between identification accuracy and verbal classifier scores to a similar degree as mock witnesses' numeric confidence judgments (Experiment 1). Crucially, for the first time, we compare the discriminative value of verbal classifier scores to the ratings of human evaluators who assessed the identical verbal confidence statements (Experiment 2). Our results suggest that human evaluators outperform the classifier when mock witnesses received no feedback; however, the classifier matches (or exceeds) the performance of human evaluators when mock witnesses received confirmatory feedback. Providing lineup information to human evaluators resulted in a worse ability to distinguish between correct and filler identifications, suggesting that this particular information may encourage the use of inappropriate heuristics when rendering accuracy judgments. Overall, these results suggest that the utility of verbal classifiers may be enhanced when contextual effects (e.g., lineup presence) impair human estimates of others' performance, but that translating witnesses' statements into classifier scores will not fix the problems of an improperly conducted lineup procedure.

Psilocybin and 4-Bromo-2,5-Dimethoxyphenethylamine (2C-B) at Encoding Distort Episodic Familiarity.

BACKGROUND: As research on psychedelics (hallucinogenic 5-HT2A agonists) progresses, it is important to delineate the reliability of supposedly unique effects across this drug class. One such effect is how psychedelics impair the formation (i.e., encoding) of hippocampal-dependent recollections (retrieval of specific details) while potentially enhancing the encoding of cortical-dependent familiarity (a feeling of knowing that a stimulus has been previously experienced). METHODS: In a double-blind, placebo-controlled, within-subjects study (N = 20), we tested the acute effects of two distinct psychedelics, psilocybin and 4-bromo-2,5-dimethoxyphenethylamine (2C-B), on the encoding of emotional episodic memories. During acute drug effects, participants viewed negative, neutral, and positive pictures. The following day (while sober), participants completed two separate memory tests for these pictures. RESULTS: Using computational models of memory confidence, we found trends for psilocybin and 2C-B at encoding to impair estimates of recollection that were supported by other measures/analyses. Surprisingly, psilocybin and 2C-B at encoding impaired estimates of familiarity, but these impairments were likely due to a misattribution of heightened familiarity, as both drugs at encoding selectively increased familiarity-based false alarms, especially for negative and positive stimuli. Psilocybin and 2C-B at encoding also tended to impair estimates of metamemory (understanding one's own memory) for negative and neutral memories but enhance estimates of metamemory for positive memories, though these effects were less reliable in additional analyses. CONCLUSIONS: Despite differences in their chemistry, pharmacology, and subjective effects, both psilocybin and 2C-B distort episodic familiarity, alluding to a common neurocognitive mechanism across psychedelics that may drive other phenomena.

Ask how they did it: untangling the relationships between task-specific strategy use, everyday strategy use, and associative memory.

OBJECTIVE: Past research has shown that self-reported everyday strategy use and task-specific strategy use are related to associative memory performance in aging. Understudied is the relationship between these types of strategy use, whether they predict associative memory performance, and how this may differ across genders. METHOD: A sample of older adults (N = 566, 53% female, ages 60-80) completed this online study. Study measures included 1. Multifactorial Memory Questionnaire (MMQ) Strategy Use subscale, a self-report measure of everyday strategy use, 2. Face-Name Task (FNT), a measure of associative memory, and 3. self-initiated number and types of strategies used on the FNT. Analyses examined the interrelationships among all study measures and their relative contributions to FNT performance while accounting for intraindividual factors. RESULTS: Participants who reported using more strategies on the FNT performed better than those who used fewer or no strategies; those who reported using at least three strategies and relating FNT to past experience performed best. Women outperformed men on the FNT but did not differ in task-specific strategy use. Participants who reported using no strategies on the FNT had lower MMQ Strategy Use scores. A multiple regression analysis indicated that female gender and using at least two task strategies were significant predictors of greater FNT performance. CONCLUSIONS: The results indicate that task-specific strategy use relates more to associative memory performance than to everyday strategy use, but neither accounts for the female advantage in FNT performance. Findings encourage querying task-specific strategy use to contextualize age-related associative memory decline.

Neuropsychiatric symptoms and metamemory across the life span: psychometric properties of the German Multifactorial Memory Questionnaire (MMQ).

OBJECTIVE: We assessed the psychometric properties, established normative data for the German Multifactorial Memory Questionnaire (MMQ), and analyzed its association with neuropsychiatric factors across the life span to provide a validated metamemory assessment for a German-speaking population. METHODS: The three MMQ scales (memory satisfaction, self-rated ability, and strategy application) were translated into German, considering cultural, linguistic, and conceptual aspects. To validate the MMQ and assess associations with neuropsychiatric factors, the Complainer Profile Identification, Geriatric Depression Scale, Beck Anxiety Inventory, Pittsburgh Sleep Quality Index, and Short-Form-Health Survey were applied in an online study in 336 healthy participants with follow-up after 8 months. RESULTS: Psychometric evaluation of the German MMQ showed normal distribution of all scales and good to excellent validity, internal consistency, and retest reliability. We provide percentiles and normative data for z-score conversion. Importantly, even subclinically elevated scores in depressiveness and anxiety were associated with decreased memory satisfaction and self-rated ability. Furthermore, although the influence of age on the German MMQ scales was minimal, effects of neuropsychiatric factors such as sleep quality, anxiety, and depressiveness on MMQ Satisfaction and Ability varied across the life span. CONCLUSIONS: Our study provides a validated German translation of the MMQ with normative data and reliability measures, including reliable change scores. We show the impact of neuropsychiatric factors on the MMQ scales across the life span and emphasize the relevance of a multifactorial approach to metamemory as a measure of individualized everyday functionality and the importance of including neuropsychiatric factors into both research and clinical assessments of metamemory.

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

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

The perceived importance of words in large font guides learning and selective memory.

People are often presented with large amounts of information to remember, and in many cases, the font size of information may be indicative of its importance (such as headlines or warnings). In the present study, we examined how learners perceive the importance of information in different font sizes and how beliefs about font size influence selective memory. In Experiment 1, participants were presented with to-be-remembered words that were either unrelated or related to a goal (e.g., items for a camping trip) in either small or large font. Participants rated words in large font as more important to remember than words in small font when the words in a list were unrelated but not when the words were schematically related to a goal. In Experiments 2 and 3, we were interested in how learners' belief that font size is indicative of importance translates to their ability to selectively encode and recall valuable information. Specifically, we presented participants with words in various font sizes, and larger fonts either corresponded to greater point values or smaller point values (values counted towards participants' scores if recalled). When larger fonts corresponded with greater point values, participants were better able to selectively remember high-value words relative to low-value words. Thus, when to-be-remembered information varies in value, font size may be less diagnostic of an item's importance (the item's importance drives memory), and when the value of information is consistent with a learner's belief, learners can better engage in selective memory.

Probing the effect of perceptual (dis)fluency on metacognitive judgments.

Despite research showing that perceptually fluent stimuli (i.e., stimuli that are easier to process) are given higher judgment of learning (JOL) ratings than perceptually disfluent stimuli, it remains unknown whether the influence of perceptual fluency on JOLs is driven by the fluent or disfluent items. Moreover, it is unclear whether this difference hinges on relative differences in fluency. The current study addressed these unanswered questions by employing (Fiacconi et al., Journal of Experimental Psychology: Learning, Memory, and Cognition 46:926-944, 2020), Journal of Experimental Psychology: Learning, Memory, and Cognition, 46[5], 926-944) letter set priming procedure. In this procedure, participants are first exposed to words containing only a subset of letters. Following this exposure, JOLs to new words composed of the same letters (i.e., fluent), and new words composed of nonexposed letters (i.e., disfluent) are compared with isolate the contribution of perceptual fluency. Because this procedure does not rely on parametric variations in perceptual features, we can directly assess the potential benefit and/or cost of fluent and disfluent items, respectively, by including neutral baseline conditions. Moreover, implementing both a mixed- and pure-list design allowed us to assess the comparative nature of perceptual fluency on JOLs. Counter to previous assumptions, our results are the first to demonstrate that perceptual disfluency decreases JOLs. Moreover, we found that the influence of perceptual disfluency on JOLs hinges on the relative differences in fluency between items even in the absence of a belief about the mnemonic impact of the fluency manipulation. These findings have important implications as they provide evidence that the difficulty, rather than ease, of information form the basis of individuals metacognitive judgments.

Predicting the memorability of scene pictures: Improved accuracy through one's own experience.

There are conflicting findings regarding the accuracy of metamemory for scene pictures. Judgements of stimulus memorability in general (memorability judgements [MJs]) have been reported to be unpredictive of actual image memorability. However, other studies have found that judgements of learning (JOLs)-predictions of one's own later memory performance for recently studied items-are moderately predictive of people's own actual recognition memory for pictures. The current study directly compared the relative accuracy and cue basis of JOLs and MJs for scene pictures. In Experiments 1 and 2, participants completed an MJ task and a JOL task in counterbalanced order. In the MJ task, they judged the general memorability of each picture. In the JOL task, they studied pictures and made JOLs during a learning phase, followed by a recognition memory test. Results showed that MJs were predictive of general scene memorability and relied on the same cues as JOLs, but MJ accuracy considerably improved after the JOL task. Experiment 3 demonstrated that prior learning experiences drove this increase in MJ accuracy. This work demonstrates that people can predict not only their own future memory performance for scene pictures with moderate accuracy but also the general memorability of scene pictures. In addition, experiences with one's own learning and memory support the ability to assess scene memorability in general. This research contributes to our understanding of the basis and accuracy of different metamemory judgements.

Meta-memory (prediction) of specific autobiographical recall: An experimental approach using a modified autobiographical memory test.

Autobiographical memory specificity is known to contribute to better mental health, social problem-solving, and episodic future thinking. While numerous studies have addressed variables that affect autobiographical memory specificity, little is known regarding the meta-memory processes that underpin memory retrieval. In this study, we introduced two meta-memory constructs, ease of retrieval judgments and anticipation of negative emotion evoked, which potentially affect autobiographical memory specificity. Participants (N = 109) first rated the ease of retrieval and anticipated emotions for positive and negative words used in a subsequent autobiographical memory test. We used the Optional Instructions of the Autobiographical Memory Test, in which participants were instructed that "specific memories are better, but other memories are permissible," allowing them to adjust how much cognitive effort they spent on generative retrieval after a failure of direct retrieval. They also self-judged whether each retrieval was generative (using additional cues with cognitive effort) or direct (immediate recall without much cognitive effort). Results showed that for generative retrieval, ease of retrieval was associated with greater specific and general memories and fewer omissions. A more negative anticipated emotion was associated with fewer specific memories and greater omissions, but was not with general memories. These results suggest that low retrievability and anticipated negative emotion prevent individuals from devoting efforts to generative retrieval. The lack of association between anticipated negative emotion and general memory calls into question the functional avoidance hypothesis regarding autobiographical memory specificity. We discussed how participants judged these meta-memories and directions for future research.

Investigating Retrospective and Prospective Metamemory Judgments During Episodic Memory in Patients With Obsessive-Compulsive Disorders.

It is clear evidence that individuals diagnosed with obsessive-compulsive disorder (OCD) lack confidence in their memory and have low metamemory performance (judgment and accuracy). However, it is still unclear whether low metamemory performance is specific to first, domain general or domain specific, and second, to stimulus domain. To address these issues, we compared individuals diagnosed with OCD and healthy controls (HCs) on recognition, retrospective (judgments of learning [JOL]) and prospective (feeling of knowing [FOK]) metamemory judgments and under three different episodic memory tasks, which consisted of symptom-free, familiar and unfamiliar stimuli (word, scene, and face photo). OCD patients showed lower recognition performance, JOL and FOK judgments, and accuracy in all tasks than HCs. Also, OCD patients were slower than HCs during all cognitive performances. In both groups, metamemory performances were lower in familiar items than unfamiliar items. However, recognition performances were not affected by stimulus type. Our results support the idea of general episodic memory and a metamemory deficit in OCD. Moreover, metamemory deficits in OCD are domain general.

Exploring the metamnemonic and phenomenal differences between transitional and mundane events.

In two experiments, we systematically investigated the reasons why people retained certain autobiographical events in their memory, as well as the properties of those events and their predicted memorability. The first experiment used three methods (word-cued, free-recalled, and "memorable, interesting, and/or important") to retrieve event memories, and examined memories from three different time-frames: very recent (within past 7 days), recent (past 2 weeks and 6 months), and older events (at least one year). In addition, data were also collected for an important transitional event recently experienced by all participants ("starting university"). The results revealed that people had access to three types of event memories: memories for life transitions, memories for older distinctive events, and memories for recent mundane events. Participants reported remembering events that were distinctive, first-time experiences, emotionally impactful, or simply because they were recent. They also predicted that older events would be more resistant to forgetting than very recent and recent events. The second experiment examined participants' memorable and forgettable events, and found that memorable events tended to be older, while forgettable events were more likely to be recent. These findings suggested that many retrievable memorable autobiographical memories were neither important nor transitional in nature. The studies contribute to our understanding of people's metamnemonic knowledge about their autobiographical memories.

Metamemory and executive function mediate the age-related decline in memory.

OBJECTIVE: Although the effect of aging on episodic memory is relatively well studied, little is known about how aging influences metamemory. In addition, while executive function (EF) is known to mediate the age-related decline in episodic memory, the role of metamemory in aging-related memory differences beyond EF remains unknown. This study aimed to elucidate the effect of aging on metamemory and to clarify the role of metamemory in the age-related decline in memory. METHOD: One hundred and four adults aged 18-79 years (50 M, 54 F) performed several EF tasks, as well as a face-scene paired-associate learning task that required them to make judgments of learning, feeling-of-knowing judgments, and retrospective confidence judgments. RESULTS: Aging was significantly associated with poor metamemory accuracy and increased confidence across metamemory judgment types, even after controlling for EF and memory performance. A parallel mediation analysis indicated that both confidence of learning and EF performance had significant partial mediation effects on the relationship between aging and memory, albeit in different ways. Specifically, poor EF explained the age-related decline in memory, whereas increased confidence of learning served to compensate for this memory decline. CONCLUSIONS: Aging is associated with general changes (i.e., poor inferences from cues) rather than specific changes (i.e., declined activation or utilization of certain cues) in metamemory monitoring. Also, changes in confidence of learning and in EF ability contribute to the preservation and decline of memory during aging, respectively. Therefore, boosting confidence during encoding and enhancing EF skills might be complementary memory intervention strategies for older adults.

How to Become a Memory: The Individual and Collective Aspects of Mnemicity.

Human adults distinguish their mental event simulations along various dimensions-most prominently according to their "mnemicity": we track whether these simulations are outcomes of past personal experiences or not (i.e., whether we are "remembering" or "imagining"). This distinction between memory and imagination is commonly thought to reflect a deep architectural distinction in the mind. Against this idea, I argue that mnemicity is not based on a fundamentalstructural difference between memories and imaginations but is instead the result of metacognitive attribution and social construction. On this attributional view, mnemicity is likely a uniquely human capacity that both serves collective functions and has been shaped by collective norms. First, on the individual level, mnemicity attribution is an outcome of metacognitive learning: it relies on acquired interpretations of the phenomenal features of mental event simulations. Such interpretations are in part acquired through interactive reminiscing with other community members. Further, how the distinction between memory and imagination is drawn is likely sensitive to cultural norms about what remembering is, when it is appropriate to claim to remember, what can be remembered, and what remembering entails. As a result, how individuals determine whether they remember or imagine is bound to be deeply enculturated. Second, mnemicity attribution solves an important collective challenge: who to grant epistemic authority about the past. Solving this challenge is important because-for humans-the past represents not just an opportunity to learn about the future but to coordinate present social realities. How a community determines such social realities both draws on individuals' remembering and in turn shapes when, what, and how individuals remember.

Judgments of learning reflect the encoding of contexts, not items: evidence from a test of recognition exclusion.

Two sources of evidence seem to be shared by judgments of past recognition and judgments of future performance: item memory or familiarity (i.e., memory for the item independent of the context in which it was experienced) and context memory or recollection (i.e., memory for the context specific to a particular prior encounter). However, there are few studies investigating the link between these two putative memory processes and judgments of learning (JOLs). We tested memory and metamemory using a continuous exclusion procedure - a modified recognition memory task where study events for two classes of items are interleaved with test trials in which the subject must endorse items from one class and reject items from the other. This procedure allowed us to estimate the influences of memory for context and memory for item on JOLs and licenses conclusions about the relative role of item and context information in supporting JOLs. An analysis of forgetting revealed that JOLs reflect both the initial degree of learning and the rate of forgetting, but only of memory for context and not of memory for items. These findings suggest that JOLs are predictive of memory for context-bound episodes, rather than for the semantic content of those episodes.

Subjective memory measures: Metamemory questionnaires currently in use.

Subjective memory evaluation is important for assessing memory abilities and complaints alongside objective measures. In research and clinical settings, questionnaires are used to examine perceived memory ability, memory complaints, and memory beliefs/knowledge. Although they provide a structured measure of self-reported memory, there is some debate as to whether subjective evaluation accurately reflects memory abilities. Specifically, the disconnect between subjective and objective memory measures remains a long-standing issue within the field. Thus, it is essential to evaluate the benefits and limitations of questionnaires that are currently in use. This review encompasses three categories of metamemory questionnaires: self-efficacy, complaints, and multidimensional questionnaires. Factors influencing self-evaluation of memory including knowledge and beliefs about memory, ability to evaluate memory, recent metamemory experiences, and affect are examined. The relationship between subjective and objective memory measures is explored, and considerations for future development and use of metamemory questionnaires are provided.

The role of dissociation-related beliefs about memory in trauma-focused treatment.

OBJECTIVE: Dysfunctional cognitions play a central role in the development of post-traumatic stress disorder (PTSD). However the role of specific dissociation-related beliefs about memory has not been previously investigated. This study aimed to investigate the role of dissociation-related beliefs about memory in trauma-focused treatment. It was hypothesized that patients with the dissociative subtype of PTSD would show higher levels of dissociation-related beliefs, dissociation-related beliefs about memory would decrease after trauma-focused treatment, and higher pre-treatment dissociation-related beliefs would be associated with fewer changes in PTSD symptoms. METHOD: Post-traumatic symptoms, dissociative symptoms, and dissociation-related beliefs about memory were assessed in a sample of patients diagnosed with PTSD (n = 111) or the dissociative subtype of PTSD (n = 61). They underwent intensive trauma-focused treatment consisting of four or eight consecutive treatment days. On each treatment day, patients received 90 min of individual prolonged exposure (PE) in the morning and 90 min of individual eye movement desensitization and reprocessing (EMDR) therapy in the afternoon. The relationship between dissociation-related beliefs about memory and the effects of trauma-focused treatment was investigated. RESULTS: Dissociation-related beliefs about memory were significantly associated with PTSD and its dissociative symptoms. In addition, consistent with our hypothesis, patients with the dissociative subtype of PTSD scored significantly higher on dissociation-related beliefs about memory pre-treatment than those without the dissociative subtype. Additionally, the severity of these beliefs decreased significantly after trauma-related treatment. Contrary to our hypothesis, elevated dissociation-related beliefs did not negatively influence treatment outcome. CONCLUSION: The results of the current study suggest that dissociation-related beliefs do not influence the outcome of trauma-focused treatment, and that trauma-focused treatment does not need to be altered specifically for patients experiencing more dissociation-related beliefs about memory because these beliefs decrease in association with treatment.

This study investigated the role of dissociation-related beliefs about memory on trauma-focused treatment.Dissociation-related beliefs were related to post-traumatic and dissociative symptoms, and were especially prominent in patients with the dissociative subtype of post-traumatic stress disorder.Dissociation-related beliefs about memory do not impact the effectiveness of trauma-focused treatment. In fact, trauma-focused treatment effectively decreased these beliefs, suggesting that dissociation-related beliefs about memory should not be a determining factor in withholding patients from receiving trauma-focused therapy.

Exploring the Role of Attentional Reorienting in the Reactive Effects of Judgments of Learning on Memory Performance.

Making judgments of learning (JOLs) while studying related word pairs can enhance performance on tests that rely on cue-target associations (e.g., cued recall) compared to studying alone. One possible explanation for this positive JOL reactivity effect is that the prompt to make JOLs, which typically occurs halfway through the presentation of each pair, may encourage learners to devote more attention to the pair during the second half of the encoding episode, which may contribute to enhanced recall performance. To investigate this idea, an online sample of participants (Experiment 1) and undergraduate students (Experiment 2) studied a set of moderately related word pairs (e.g., dairy-cow) in preparation for a cued recall test. Some participants made JOLs for each pair halfway through the presentation, whereas other participants did not. Also, some participants were presented with a fixation point halfway through the presentation, whereas other participants were not. The goal of this fixation point was to simulate the possible "reorienting" effect of a JOL prompt halfway through each encoding episode. In both an unsupervised online context and a supervised laboratory context, cued recall performance was higher for participants who made JOLs compared to those who did not make JOLs. However, presenting a fixation point halfway through the presentation of each pair did not lead to reactive effects on memory. Thus, JOLs are more effective than a manipulation that reoriented participants to the word pairs in another way (i.e., via a fixation point), which provides some initial evidence that positive reactivity for related pairs is not solely driven by attentional reorienting during encoding.

Differential effects of remotely supervised transcranial direct current stimulation on recognition memory depending on task order.

Background: Prior work has shown positive effects of High Definition transcranial direct current stimulation (HD-tDCS) over the dorsolateral prefrontal cortex (DLPFC) on semantic memory performance and metamemory monitoring accuracy. However, HD-tDCS requires setup by a trained researcher, which is not always feasible. Few studies have used remotely supervised (rs) tDCS in healthy populations, and remote supervision has strong practical benefits. Objective/hypothesis: The goal of the current study was to test if previously shown effects of HD-tDCS over the left DLPFC on semantic memory performance and metamemory monitoring accuracy extended to conventional rs-tDCS, which is less focal than HD-tDCS, and to episodic memory and metamemory tasks. Materials and methods: A total of 36 healthy participants completed 6 weeks of rs-tDCS sessions, with either active left or right anodal DLPFC stimulation, or sham. Participants completed semantic and episodic memory and metamemory tasks, which each lasted for three consecutive sessions, and session order was counterbalanced across participants. Results: Overall, there were no main effects of rs-tDCS on metamemory monitoring accuracy or memory performance for either the semantic or the episodic tasks. However, there were effects of rs-tDCS that depended on the order of completing the episodic and semantic task sessions. When participants completed the semantic task sessions after the episodic task sessions, semantic recognition was greater in the left anodal DLPFC condition. In a parallel effect, when participants completed the episodic task sessions after the semantic task sessions, episodic recognition was greater in the right anodal DLPFC condition. Conclusion: Prior experience with tDCS is a factor for effects of rs-tDCS on cognition. Additionally, the current experiment provides evidence for the feasibility of fully remotely supervised tDCS in healthy participants.