Episodic Memory Retrieval Research Articles

Dopamine is a double-edged sword: dopaminergic modulation enhances memory retrieval performance but impairs metacognition.

While memory encoding and consolidation processes have been linked with dopaminergic signaling for a long time, the role of dopamine in episodic memory retrieval remained mostly unexplored. Based on previous observations of striatal activity during memory retrieval, we used pharmacological functional magnetic resonance imaging to investigate the effects of dopamine on retrieval performance and metacognitive memory confidence in healthy humans. Dopaminergic modulation by the D2 antagonist haloperidol administered acutely during the retrieval phase improved recognition accuracy of previously learned pictures significantly and was associated with increased activity in the substantia nigra/ventral tegmental area, locus coeruleus, hippocampus, and amygdala during retrieval. In contrast, confidence for new decisions was impaired by unsystematically increased activity of the striatum across confidence levels and restricted range of responsiveness in frontostriatal networks under haloperidol. These findings offer new insights into the mechanisms underlying memory retrieval and metacognition and provide a broader perspective on the presence of memory problems in dopamine-related diseases and the treatment of memory disorders.

Retrospective attribution of false beliefs in 3-year-old children

A current debate in psychology and cognitive science concerns the nature of young children's ability to attribute and track others' beliefs. Beliefs can be attributed in at least two different ways: prospectively, during the observation of belief-inducing situations, and in a retrospective manner, based on episodic retrieval of the details of the events that brought about the beliefs. We developed a task in which only retrospective attribution, but not prospective belief tracking, would allow children to correctly infer that someone had a false belief. Eighteen- and 36-month-old children observed a displacement event, which was witnessed by a person wearing sunglasses (Experiment 1). Having later discovered that the sunglasses were opaque, 36-month-olds correctly inferred that the person must have formed a false belief about the location of the objects and used this inference in resolving her referential expressions. They successfully performed retrospective revision in the opposite direction as well, correcting a mistakenly attributed false belief when this was necessary (Experiment 3). Thus, children can compute beliefs retrospectively, based on episodic memories, well before they pass explicit false-belief tasks. Eighteen-month-olds failed in such a task, suggesting that they cannot retrospectively attribute beliefs or revise their initial belief attributions. However, an additional experiment provided evidence for prospective tracking of false beliefs in 18-month-olds (Experiment 2). Beyond identifying two different modes for tracking and updating others' mental states early in development, these results also provide clear evidence of episodic memory retrieval in young children.

Entrainment enhances theta oscillations and improves episodic memory

ABSTRACTNeural oscillations in the theta band have been linked to episodic memory, but it is unclear whether activity patterns that give rise to theta play a causal role in episodic retrieval. Here, we used rhythmic auditory and visual stimulation to entrain neural oscillations to assess whether theta activity contributes to successful memory retrieval. In two separate experiments, human subjects studied words and were subsequently tested on memory for the words (‘item recognition’) and the context in which each had been previously studied (‘source memory’). Between study and test, subjects in the entrainment groups were exposed to audiovisual stimuli designed to enhance activity at 5.5 Hz, whereas subjects in the control groups were exposed to white noise (Expt. 1) or 14 Hz entrainment (Expt. 2). Theta entrainment selectively increased source memory performance in both studies. Electroencephalography (EEG) data in Expt. 2 revealed that theta entrainment resulted in band-specific enhancement of theta power during the entrainment period and during post-entrainment memory retrieval. These results demonstrate a direct link between theta activity and episodic memory retrieval. Targeted manipulation of theta activity could be a promising new approach to enhance theta activity and memory performance in healthy individuals and in patients with memory disorders.

Le réseau cérébral par défaut : un repos qui n’en est pas un

Le reseau cerebral par defaut comprend un groupe de regions plus actives lorsqu’un individu est au repos que lorsqu’il est engage dans une tâche cognitive. Le reseau comprend le cortex cingulaire posterieur, le cortex prefrontal medial, le cortex parietal inferieur et le lobe temporal interne. En imagerie par resonance magnetique fonctionnelle (IRMf) au repos, ces regions ont une activite qui covarie au cours du temps. Les etudes qui ont examine les correlats cognitifs du reseau cerebral par defaut ont montre son implication dans diverses tâches, incluant la recuperation en memoire episodique et en memoire autobiographique, la projection dans le futur, les traitements autoreferentiels et la theorie de l’esprit. Selon l’hypothese de la cognition interne, l’implication du reseau par defaut dans toutes ces tâches refleteraient son role general dans la modelisation mentale de scenarios potentiels et l’integration personnelle des evenements percus et rememores afin de preparer les individus a reagir aux evenements a venir. Une autre hypothese considere que la fonction du reseau par defaut transcenderait la conscience et refleterait l’architecture intrinseque du cerveau ou plusieurs systemes seraient continuellement actifs et ou le reseau par defaut, de par sa connectivite intense, jouerait le role de coordinateur facilitant la reactivite des autres systemes a tout changement dans l’environnement.

Development and Decline of the Hippocampal Long-Axis Specialization and Differentiation During Encoding and Retrieval of Episodic Memories.

Change in hippocampal function is a major factor in life span development and decline of episodic memory. Evidence indicates a long-axis specialization where anterior hippocampus is more engaged during encoding than during retrieval, and posterior more engaged during retrieval than during encoding. We tested the life span trajectory of hippocampal long-axis episodic memory-related activity and functional connectivity (FC) in 496 participants (6.8-80.8 years) encoding and retrieving associative memories. We found evidence for a long-axis encoding-retrieval specialization that declined linearly during development and aging, eventually vanishing in the older adults. This was mainly driven by age effects on retrieval, which was associated with gradually lower activity from childhood to adulthood, followed by positive age relationships until 70 years. This pattern of age effects characterized task engagement regardless of memory success or failure. Especially for retrieval, children engaged posterior hippocampus more than anterior, while anterior was relatively more activated already in teenagers. Significant intrahippocampal connectivity was found during task, which declined with age. The results suggest that hippocampal long-axis differentiation and communication during episodic memory tasks develop rapidly during childhood, are different in older compared with younger adults, and that the age effects are related to task engagement, not the successful retrieval of episodic memories specifically.

Evidence for Reduced Autobiographical Memory Episodic Specificity in Cognitively Normal Middle-Aged and Older Individuals at Increased Risk for Alzheimer's Disease Dementia.

Alzheimer's disease (AD) typically eludes clinical detection for years, if not decades. The identification of subtle cognitive decline associated with preclinical AD would not only advance understanding of the disease, but also provide clinical targets to assess preventative and early intervention treatments. Disrupted retrieval of detailed episodic autobiographical memories may be a sensitive indicator of subtle cognitive decline, because this type of memory taxes a core neural network affected by preclinical AD neuropathology. To begin to address this idea, we assessed the episodic specificity of autobiographical memories retrieved by cognitively normal middle-aged and older individuals who are carriers of the apolipoprotein E ε4 allele - a population at increased risk for subtle cognitive decline related to neuropathological risk factors for AD. We compared the ε4 carriers to non-carriers of ε4 similar in age, education, and gender. The ε4 carriers did not perform worse than the non-carriers on a comprehensive battery of neuropsychological tests. In contrast, as a group, the ε4 carriers generated autobiographical memories that were reduced in "internal" or episodic details relative to non-carriers. These findings support the notion that reduced autobiographical episodic detail generation may be a marker of subtle cognitive decline associated with AD. (JINS, 2018, 24, 1073-1183).

Core Network Contributions to Remembering the Past, Imagining the Future, and Thinking Creatively.

The core network refers to a set of neural regions that have been consistently associated with episodic memory retrieval and episodic future simulation. This network is thought to support the constructive thought processes that allow the retrieval and flexible combination of stored information to reconstruct past and construct novel future experiences. Recent behavioral research points to an overlap between these constructive processes and those also engaged during divergent thinking-the ability to think creatively and generate novel ideas-but the extent to which they involve common neural correlates remains unclear. Using fMRI, we sought to address this question by assessing brain activity as participants recalled past experiences, simulated future experiences, or engaged in divergent thinking. Consistent with past work, we found that episodic retrieval and future simulation activated the core network compared with a semantic control condition. Critically, a triple conjunction of episodic retrieval, future simulation, and divergent thinking revealed common engagement of core network regions, including the bilateral hippocampus and parahippocampal gyrus, as well as other regions involved in memory retrieval (inferior frontal gyrus) and mental imagery (middle occipital gyrus). The results provide further insight into the roles of the hippocampus and the core network in episodic memory retrieval, future simulation, and divergent thinking and extend recent work highlighting the involvement of constructive episodic processes in creative cognition.

Stress Impairs Episodic Retrieval by Disrupting Hippocampal and Cortical Mechanisms of Remembering.

Despite decades of science investigating the neural underpinnings of episodic memory retrieval, a critical question remains: how does stress influence remembering and the neural mechanisms of recollection in humans? Here, we used functional magnetic resonance imaging and multivariate pattern analyses to examine the effects of acute stress during retrieval. We report that stress reduced the probability of recollecting the details of past experience, and that this impairment was driven, in part, by a disruption of the relationship between hippocampal activation, cortical reinstatement, and memory performance. Moreover, even memories expressed with high confidence were less accurate under stress, and this stress-induced decline in accuracy was explained by reduced posterior hippocampal engagement despite similar levels of category-level cortical reinstatement. Finally, stress degraded the relationship between the engagement of frontoparietal control networks and retrieval decision uncertainty. Collectively, these findings demonstrate the widespread consequences of acute stress on the neural systems of remembering.

Differentiation of Human Medial Prefrontal Cortex Activity Underlies Long-Term Resistance to Forgetting in Memory.

It is well known that distributing study events over time leads to better memory over long time scales, compared with massing study events together. One explanation for such long-term resistance to forgetting is that distributed study leads to neural differentiation in memory, which supports retrieval of past experiences by disambiguating highly similar memory representations. Neuroanatomical models of episodic memory retrieval propose that the hippocampus and medial prefrontal cortex (MPFC) work together to enable retrieval of behaviorally appropriate memories. However, it is not known how representations in these regions jointly support resistance to forgetting long after initial learning. Using fMRI, we measured differentiation in retrieved memory representations following an extended delay in male and female human participants. After 1 week, word-object associations were better remembered if studied across 2 d (overnight), allowing associations to be learned in distinct temporal contexts, compared with learning within a single day (same day). MPFC retrieval patterns showed differentiation for overnight relative to same day memories, whereas hippocampal patterns reflected associative retrieval success. Overnight memory differentiation in MPFC was higher for associative than item memories and higher than differentiation assessed over a brain-wide set of retrieval-active voxels. The memory-related difference in MPFC pattern differentiation correlated with memory success for overnight learning and with hippocampal-MPFC functional connectivity. These results show that learning information across days leads to differentiated MPFC memory representations, reducing forgetting after 1 week, and suggest this arises from persistent interactions between MPFC and hippocampus.SIGNIFICANCE STATEMENT Neural activity in both the hippocampus and medial prefrontal cortex (MPFC) has been linked to memory-related representations, but prior work has not examined how these representations support episodic memory retrieval over extended time scales that are characteristic of everyday retrieval. We show that differentiation in MPFC activity 1 week after encoding is higher for retrieved information learned across 2 d compared with within a single day. In hippocampus, differentiation was greater for detailed memory retrieval but was not influenced by whether information had been learned over 1 or 2 d. Differentiation in MPFC predicted behavioral robustness to forgetting and was correlated with hippocampal-MPFC connectivity. The results suggest that context-based differentiation supports robust long-term memory via persistent MPFC-hippocampal interactions.

Speech Registration in Symptomatic Memory Impairment.

Background: An inability to recall recent conversations often indicates impaired episodic memory retrieval. It may also reflect a failure of attentive registration of spoken sentences which leads to unsuccessful memory encoding. The hypothesis was that patients complaining of impaired memory would demonstrate impaired function of “multiple demand” (MD) brain regions, whose activation profile generalizes across cognitive domains, during speech registration in naturalistic listening conditions.Methods: Using functional MRI, brain activity was measured in 22 normal participants and 31 patients complaining of memory impairment, 21 of whom had possible or probable Alzheimer’s disease (AD). Participants heard a target speaker, either speaking alone or in the presence of distracting background speech, followed by a question to determine if the target speech had been registered.Results: Patients performed poorly at registering verbal information, which correlated with their scores on a screening test of cognitive impairment. Speech registration was associated with widely distributed activity in both auditory cortex and in MD cortex. Additional regions were most active when the target speech had to be separated from background speech. Activity in midline and lateral frontal MD cortex was reduced in the patients. A central cholinesterase inhibitor to increase brain acetylcholine levels in half the patients was not observed to alter brain activity or improve task performance at a second fMRI scan performed 6–11 weeks later. However, individual performances spontaneously fluctuated between the two scanning sessions, and these performance differences correlated with activity within a right hemisphere fronto-temporal system previously associated with sustained auditory attention.Conclusions: Midline and lateralized frontal regions that are engaged in task-dependent attention to, and registration of, verbal information are potential targets for transcranial brain stimulation to improve speech registration in neurodegenerative conditions.

Mitigating the adverse effects of response deadline on recognition memory: Differential effects of semantic memory support on item and associative memory

Abstract Prior research indicates that the effects of response deadline on episodic memory retrieval may be selective. Accordingly, this paper examines whether response deadline causes differential impairments in item and associative memory. Further, it investigates and contrasts the role of two types of semantic memory support– item memory support (in the form of meaningfulness of items, Experiment 1) and associative memory support (in the form of relatedness between items, Experiment 2), in potentially alleviating these episodic memory impairments. Across two experiments, participants studied pairs composed of pictures (presented as brand logo graphics) and words (presented as brand names), and later were tested on the components (item recognition) or the association between the components (associative recognition) under either long or short response deadlines. The results demonstrate the differential effects of response deadline on recognition memory, with larger detriments caused in associative memory versus item memory. Furthermore, while meaningfulness of items attenuates the negative effects of response deadline on item (versus associative) recognition (Experiment 1), relatedness between items alleviates the adverse effects of response deadline on associative (versus item) recognition (Experiment 2), though this was not the case in a boundary condition in which related pairs were used as foils, posing greater demand on recollection processes. The results are interpreted to indicate that the attenuation of the negative effects of response deadline on recognition memory occurs in the type of episodic memory that receives greater semantic memory support.

Neural correlates of glucocorticoids effects on autobiographical memory retrieval in healthy women

It is well known that elevated cortisol after stress or after exogenous administration impairs episodic memory retrieval including autobiographical memory (AM) retrieval. This impairment might be mediated by deactivation of a neural network associated with memory retrieval including the prefrontal cortex (PFC) and limbic structures. However, the neural underpinnings of these cortisol effects on AM retrieval have not been investigated yet.In this study, thirty-three healthy women received either placebo or 10 mg hydrocortisone in a double blind cross-over design before completing an AM test during fMRI. In this test, participants are asked to recall specific events from their own past in response to a cue word.In a first step, we analyzed the neural underpinnings of AM retrieval in the placebo condition. We found an activation pattern consistent with core regions involved in autobiographical memory recall, including the ventromedial PFC, anterior medial (am)PFC, inferior frontal gyrus, the posterior cingulate cortex, the tempoparietal junction, the middle temporal gyrus and the hippocampus. Further, we analyzed brain activation during AM retrieval after hydrocortisone compared to placebo. Region of interest (ROI) analyses revealed a hydrocortisone-induced deactivation during AM retrieval in the right amPFC. Results of the ROI analyses were non-significant in the left and right hippocampus, the left and right vmPFC and the left amPFCIn sum, during AM retrieval hydrocortisone had the most pronounced effects on the amPFC. This might be explained by the strong involvement of this brain region in self-referential behavior, which is essential for recalling autobiographic information.

The reduction of adult neurogenesis in depression impairs the retrieval of new as well as remote episodic memory.

Major depressive disorder (MDD) is associated with an impairment of episodic memory, but the mechanisms underlying this deficit remain unclear. Animal models of MDD find impaired adult neurogenesis (AN) in the dentate gyrus (DG), and AN in DG has been suggested to play a critical role in reducing the interference between overlapping memories through pattern separation. Here, we study the effect of reduced AN in MDD on the accuracy of episodic memory using computational modeling. We focus on how memory is affected when periods with a normal rate of AN (asymptomatic states) alternate with periods with a low rate (depressive episodes), which has never been studied before. Also, unlike previous models of adult neurogenesis, which consider memories as static patterns, we model episodic memory as sequences of neural activity patterns. In our model, AN adds additional random components to the memory patterns, which results in the decorrelation of similar patterns. Consistent with previous studies, higher rates of AN lead to higher memory accuracy in our model, which implies that memories stored in the depressive state are impaired. Intriguingly, our model makes the novel prediction that memories stored in an earlier asymptomatic state are also impaired by a later depressive episode. This retrograde effect exacerbates with increased duration of the depressive episode. Finally, pattern separation at the sensory processing stage does not improve, but rather worsens, the accuracy of episodic memory retrieval, suggesting an explanation for why AN is found in brain areas serving memory rather than sensory function. In conclusion, while cognitive retrieval biases might contribute to episodic memory deficits in MDD, our model suggests a mechanistic explanation that affects all episodic memories, regardless of emotional relevance.

Episodic memory retrieval is impaired in negative schizotypy under fast response deadline

Schizotypy offers a useful, multidimensional framework for understanding the development and expression of schizophrenia-spectrum psychopathology. Nonclinically ascertained young adults who endorse positive and negative schizotypy traits exhibit similar, albeit milder, versions of the symptoms and impairment seen in schizophrenia-spectrum disorders. Previous studies have demonstrated that negative, but not positive, schizotypy is associated with impairment in free-recall, recognition, and source memory. Furthermore, these deficits appear to result from context processing deficits in negative schizotypy. However, neither positive nor negative schizotypy were associated with variation in the set size effect. The present study further examined the association with set-size effect under fast and slow response deadlines across the schizotypy continuum. We replicated the finding that the set size effect was invariant across both positive and negative schizotypy dimensions. However, negative schizotypy was associated with poorer overall recall, and the negative schizotypy by response deadline interaction revealed that negative schizotypy was differentially impaired by the speeded responding in overall memory. Despite instructions to guess on the cued-recall task, negative schizotypy was associated with increased likelihood of omission errors (failing to produce a response), whereas positive schizotypy was associated with decreased omission errors. The findings provide further support for the multidimensional model of schizotypy and previous findings that negative schizotypy is associated with impaired retrieval, especially under fast response deadlines.

Gender dependent contribution of muscarinic receptors in memory retrieval under sub-chronic stress

Stress induces retrograde amnesia in humans and rodents. Muscarinic antagonism under normal physiological conditions causes gender dependent impairment in episodic memory retrieval. We aimed to explore the gender dependent role of muscarinic receptors in memory retrieval under sub-chronic stress condition. Male and female mice were trained for Morris water maze test and contextual fear conditioning, followed by 3 h restraint stress per day for five days. Stress was either given alone or in combination with a daily subcutaneous injection of scopolamine (1 mg/kg) or donepezil (1 mg/kg). Control mice were given saline without any stress. Sub-chronic stress (induced for five days) impaired spatial memory retrieval in males (P < 0.005) but not in females (P > 0.05). Stress induced spatial memory recall deficit in male mice was independent of muscarinic receptor activity (P > 0.05). However, stress induced contextual fear memory recall impairment was reversed by donepezil treatment in male (P < 0.005) and female (P < 0.0001) mice. These findings suggest that differential role of muscarinic activity in retrieving different types of memories under stress depends on gender of subjects.

Δ9-Tetrahydrocannabinol at Retrieval Drives False Recollection of Neutral and Emotional Memories

BackgroundIt is well established that the main psychoactive constituent of cannabis, Δ9-tetrahydrocannabinol (THC), impairs episodic memory encoding and modulates emotional processing, but little is known about the impact of THC during the retrieval of emotional episodic memories. With the rise of cannabis to treat medical conditions, including those characterized by emotional and episodic memory disturbances, there is an urgent need to determine the effects of THC on memory accuracy and distortion. Here, we report the first study investigating the effects of THC during retrieval of neutral and emotional episodic memories. MethodsUsing a double-blind, placebo-controlled, within-subjects design, healthy volunteers (N = 23) viewed negative, neutral, and positive pictures (emotional memory task) and lists of semantically related words (false memory task). Forty-eight hours later, participants ingested a capsule containing either THC (15 mg) or placebo and completed tasks to test their memories for the previously studied pictures and words. ResultsTHC during retrieval did not reduce the number of correct responses to studied items. Instead, it robustly increased false recollection on both the emotional memory and false memory tasks. This effect was found for both neutral and emotional items. ConclusionsThese findings show that THC has adverse effects during memory retrieval, distorting both neutral and emotional memories. Coupled with THC’s known effects during encoding, these new retrieval findings are important in light of the spreading acceptance of cannabis.

Neural activation and memory for natural scenes: Explicit and spontaneous retrieval.

Stimulus repetition elicits either enhancement or suppression in neural activity, and a recent fMRI meta-analysis of repetition effects for visual stimuli (Kim, 2017) reported cross-stimulus repetition enhancement in medial and lateral parietal cortex, as well as regions of prefrontal, temporal, and posterior cingulate cortex. Repetition enhancement was assessed here for repeated and novel scenes presented in the context of either an explicit episodic recognition task or an implicit judgment task, in order to study the role of spontaneous retrieval of episodic memories. Regardless of whether episodic memory was explicitly probed or not, repetition enhancement was found in medial posterior parietal (precuneus/cuneus), lateral parietal cortex (angular gyrus), as well as in medial prefrontal cortex (frontopolar), which did not differ by task. Enhancement effects in the posterior cingulate cortex were significantly larger during explicit compared to implicit task, primarily due to a lack of functional activity for new scenes. Taken together, the data are consistent with an interpretation that medial and (ventral) lateral parietal cortex are associated with spontaneous episodic retrieval, whereas posterior cingulate cortical regions may reflect task or decision processes.

Mind-to-mind heteroclinic coordination: Model of sequential episodic memory initiation.

Retrieval of episodic memory is a dynamical process in the large scale brain networks. In social groups, the neural patterns, associated with specific events directly experienced by single members, are encoded, recalled, and shared by all participants. Here, we construct and study the dynamical model for the formation and maintaining of episodic memory in small ensembles of interacting minds. We prove that the unconventional dynamical attractor of this process-the nonsmooth heteroclinic torus-is structurally stable within the Lotka-Volterra-like sets of equations. Dynamics on this torus combines the absence of chaos with asymptotic instability of every separate trajectory; its adequate quantitative characteristics are length-related Lyapunov exponents. Variation of the coupling strength between the participants results in different types of sequential switching between metastable states; we interpret them as stages in formation and modification of the episodic memory.

Human Episodic Memory Retrieval Is Accompanied by a Neural Contiguity Effect.

Cognitive psychologists have long hypothesized that experiences are encoded in a temporal context that changes gradually over time. When an episodic memory is retrieved, the state of context is recovered-a jump back in time. We recorded from single units in the medial temporal lobe of epilepsy patients performing an item recognition task. The population vector changed gradually over minutes during presentation of the list. When a probe from the list was remembered with high confidence, the population vector reinstated the temporal context of the original presentation of that probe during study, a neural contiguity effect that provides a possible mechanism for behavioral contiguity effects. This pattern was only observed for well remembered probes; old probes that were not well remembered showed an anti-contiguity effect. These results constitute the first direct evidence that recovery of an episodic memory in humans is associated with retrieval of a gradually changing state of temporal context, a neural "jump back in time" that parallels the act of remembering.SIGNIFICANCE STATEMENT Episodic memory is the ability to relive a specific experience from one's life. For decades, researchers have hypothesized that, unlike other forms of memory that can be described as simple associations between stimuli, episodic memory depends on the recovery of a neural representation of spatiotemporal context. During study of a sequence of stimuli, the brain state of epilepsy patients changed slowly over at least a minute. When the participant remembered a particular event from the list, this gradually changing state was recovered. This provides direct confirmation of the prediction from computational models of episodic memory. The resolution of this point means that the study of episodic memory can focus on the mechanisms by which this representation of spatiotemporal context is maintained and sometimes recovered.

The role of KIBRA in reconstructive episodic memory

BackgroundIn order to retrieve episodic past events, the missing information needs to be reconstructed using information stored in semantic memory. Failures in these reconstructive processes are expressed as false memories. KIBRA single nucleotide polymorphism (rs17070145) has been linked to episodic memory performance as well as an increased risk of Alzheimer’s disease and post-traumatic stress disorder (PTSD).MethodsHere, the role of KIBRA rs17070145 polymorphism (male and female CC vs. CT/TT carriers) in reconstructive episodic memory in the Deese-Roediger-McDermott (DRM) paradigm was investigated in N = 219 healthy individuals.ResultsFemale participants outperformed males in the free recall condition. Furthermore, a trend towards a gender x genotype interaction was found for false recognition rates. Female CT/TT carriers exhibited a lower proportion of false recognition rates for associated critical lures as compared to male CT/TT. Additionally, an association between KIBRA rs17070145 genotype, familiarity and recollection based recognition performance was found. In trials with correct recognition of listed items CT/TT carriers showed more “remember”, but fewer “know” responses as compared to CC carriers.Discussion and conclusionOur findings suggest that the T-allele of KIBRA rs17070145 supports recollection based episodic memory retrieval and contributes to memory accuracy in a gender dependent manner. Findings are discussed in the context of the specific contribution of KIBRA related SNPs to reconstructive episodic memory and its implications for cognitive and emotional symptoms in dementia and PTSD.