Implementation of activities of daily living retraining for individuals in post-traumatic amnesia.

Background Despite evidence of the efficacy of activities of daily living (ADL) retraining during post-traumatic amnesia (PTA) following traumatic brain injury (TBI), utilisation of this intervention in practice is unclear. Utilising an implementation science framework, the Consolidated Framework for Implementation Research, this study explored efforts to translate ADL retraining during PTA into the clinical practice of occupational therapists (OTs) working in TBI rehabilitation settings across Australia. Methods Participants were 44 OTs who attended a day-long training workshop that included knowledge and skill-based content regarding ADL retraining during PTA. Baseline and post-training ratings were completed including evaluation of workshop utility, and skill and knowledge-based competencies relevant to the intervention. Approximately 2 years later, nine trained OTs and two administrators were interviewed to explore the results of implementing the intervention. Results Overall, the training workshop was rated as being helpful and OT ratings of confidence (P P Conclusion Multiple barriers were identified in implementation of ADL retraining during PTA and require consideration to facilitate translation and promote best practice.

Post-traumatic amnesia: a scoping review & content analysis of behavioral disturbances.

OBJECTIVE: The aim of this scoping review was to identify behavioral disturbances exhibited by patients in post-traumatic amnesia (PTA). While behavioral disturbances are common in PTA, research into their presentation and standardized measures for their assessment are limited. DESIGN: The study protocol was registered with PROSPERO (CRD42021268275). A scoping review of databases was performed according to pre-determined criteria on 29 July 2021 and updated on 13 July 2022. A conventional content analysis was used to examine and categorize behavioral disturbances. RESULTS: Thirty papers met the inclusion criteria, of which 27 reported observations and/or scores obtained on behavioral scales, and 3 on clinician interviews and surveys. None focused exclusively on children. Agitation was the most frequently assessed behavior, and Agitated Behavior Scale was the most used instrument. Content analysis, however, bore eight broad behavioral categories: disinhibition, agitation, aggression, lability, lethargy/low mood, perceptual disturbances/psychotic symptoms, personality change and sleep disturbances. CONCLUSION: Our study revealed that while standardized assessments of behavior of patients in PTA are often limited to agitation, clinical descriptions include a range of behavioral disturbances. Our study highlights a significant gap in the systematic assessment of a wide range of behavioral disturbances observed in PTA.

A partial habituation method to test for anterograde and retrograde amnestic treatment effects: Evidence that antagonism of the NMDA receptor can induce anterograde but not retrograde amnestic effects.

BACKGROUND: A progressive decrease in spontaneous locomotion with repeated exposure to a novel environment has been assessed using both within and between-session measures. While both are well-established and reliable measurements, neither are useful alone as methods to concurrently assess treatment effects on acquisition and retention of habituation. NEW METHOD: We report a behavioral method that measures habituation by combining the within and between measurements of locomotion. We used a 30 min session divided into 6 five min blocks. In the first novel environment session activity was maximal in the first 5 min block but was reduced to a low level by the sixth block, indicative of within-session habituation. Using 8 daily sessions, we showed that this terminal block low level of activity progressed incrementally to the first block to achieve complete habituation. RESULTS/COMPARISON WITH EXISTING METHODS: Within-session activity across sessions was used to identify different stages of between session habituation. It was then possible to assess drug treatment effects from partial to complete habituation, so that treatment effects on retention of the previously acquired partial habituation, expressed as a reversion to an earlier within session habituation pattern (retrograde amnesia assessment), as well as the effects on new learning by the failure in subsequent sessions to acquire complete between-session habituation (anterograde amnesia assessment). CONCLUSIONS: The use of spontaneous motor activity to assess learning and memory effects provides the opportunity to assess direct treatment effects on behavior and motor activity in contrast to many learning and memory models.

Retrograde amnesia for the stress-induced impairment of extinction: time-dependent and not so forgotten.

We investigated whether retrograde amnesia for the stress-induced impairment of extinction retrieval shares similar characteristics with original acquisition memories. The first experiment demonstrated that cycloheximide administered shortly after a single restraint stress session alleviated the impairment of extinction retrieval but not when administered following a longer delay (i.e., the amnesia for stress is time-dependent). A second experiment showed that the retrograde amnesia for stress could be alleviated by a second brief exposure to the stressor. These results demonstrating that amnesia for stress shares characteristics similar to original memories are explained using a retrieval-based memory integration model of retrograde amnesia.

Epigenetic Processes of DNA Methylation Are Selectively Involved in the Mechanisms of Retrograde and Anteograde Amnesia.

The participation of DNA methylation processes in the mechanisms of anterograde and retrograde amnesia caused by impaired reconsolidation of conditioned food aversion memory by NMDA glutamate receptor antagonists or serotonin receptor antagonists, respectively, were studied on grape snails. Anterograde amnesia was characterized by impaired formation of long-term memory during repeated learning. Administration of a DNA methyltransferase (DNMT) inhibitor to amnestic animals resulted in accelerated formation of long-term memory during 1 day of repetitive training vs 3 days during initial training. In serotonin-dependent retrograde amnesia, repeated learning without DNMT inhibitor administration or after inhibitor injections led to the formation of long-term memory. The dynamics of memory formation was similar in both cases and did not differ from that during the initial training: the memory was formed within 3 days of training. Thus, epigenetic processes of DNA methylation are selectively involved in the mechanisms of anterograde amnesia, but do not participate in the mechanisms of retrograde amnesia.

Retrograde amnesia abolishes the self-reference effect in anterograde memory.

Is retrograde amnesia associated with an ability to know who we are and imagine what we will be like in the future? To answer this question, we had S.G., a patient with focal retrograde amnesia following hypoxia, two brain-damaged (control) patients with no retrograde memory deficits, and healthy controls judge whether each of a series of trait adjectives was descriptive of their present self, future self, another person, and that person in the future, and later recognize studied traits among distractors. Healthy controls and control patients were more accurate in recognizing self-related compared to other-related traits, a phenomenon known as the self-reference effect (SRE). This held for both present and future self-views. By contrast, no evidence of (present or future) SRE was observed in SG, who concomitantly showed reduced certainty about his personality traits. These findings indicate that retrograde amnesia can weaken the self-schema and preclude its instantiation during self-related processing.

Prolonged duration of post-traumatic amnesia: A sensitive classification for predicting cognitive outcomes in children recovering from traumatic brain injury.

OBJECTIVE: A paucity of data exists regarding the duration of post-traumatic amnesia (PTA) as a predictor of cognitive functioning among children after traumatic brain injury (TBI). The study aimed to assess the relationship between PTA duration and areas of neurocognitive function among the pediatric population in the sub-acute phase of recovery and rehabilitation. METHODS: Data were collected from medical files on 103 children aged 5.5-16.5 hospitalized at a pediatric rehabilitation department with a diagnosis of moderate-severe TBI (msTBI) between the years 2004-2019. The Children Orientation and Amnesia Test was used to evaluate PTA duration. Measures of high-order cognitive abilities of attention and executive function were collected using the Test of Everyday Attention-Child version (TEA-Ch). RESULTS: Three PTA duration groups were assembled out of a cluster analysis: "Long PTA" (M = 21 days), "Very Long PTA" (M = 47 days), and "Extremely Long PTA" (M = 94 days). Analyses revealed that the "Long PTA" group preformed significantly better than the "Very Long PTA" and "Extremely Long PTA" groups on all TEA-Ch measures, that is, Selective Attention, Attentional Control Switching, and Sustained Attention. CONCLUSIONS: This study is the first to demonstrate that PTA duration is a useful predictor of high-order cognitive functions among children with msTBI in the sub-acute phase of recovery and rehabilitation. The findings emphasize the importance of using a more sensitive classification of prolonged PTA durations to improve outcome prediction and allocation of resources to those who can benefit most after severe brain injuries.

Restoring myocardial infarction-induced long-term memory impairment by targeting the cystic fibrosis transmembrane regulator.

BACKGROUND: Cognitive impairment is a serious comorbidity in heart failure patients, but effective therapies are lacking. We investigated the mechanisms that alter hippocampal neurons following myocardial infarction (MI). METHODS: MI was induced in male C57Bl/6 mice by left anterior descending coronary artery ligation. We utilised standard procedures to measure cystic fibrosis transmembrane regulator (CFTR) protein levels, inflammatory mediator expression, neuronal structure, and hippocampal memory. Using in vitro and in vivo approaches, we assessed the role of neuroinflammation in hippocampal neuron degradation and the therapeutic potential of CFTR correction as an intervention. FINDINGS: Hippocampal dendrite length and spine density are reduced after MI, effects that associate with decreased neuronal CFTR expression and concomitant microglia activation and inflammatory cytokine expression. Conditioned medium from lipopolysaccharide-stimulated microglia (LCM) reduces neuronal cell CFTR protein expression and the mRNA expression of the synaptic regulator post-synaptic density protein 95 (PSD-95) in vitro. Blocking CFTR activity also down-regulates PSD-95 in neurons, indicating a relationship between CFTR expression and neuronal health. Pharmacologically correcting CFTR expression in vitro rescues the LCM-mediated down-regulation of PSD-95. In vivo, pharmacologically increasing hippocampal neuron CFTR expression improves MI-associated alterations in neuronal arborisation, spine density, and memory function, with a wide therapeutic time window. INTERPRETATION: Our results indicate that CFTR therapeutics improve inflammation-induced alterations in hippocampal neuronal structure and attenuate memory dysfunction following MI. FUNDING: Knut and Alice Wallenberg Foundation [F 2015/2112]; Swedish Research Council [VR; 2017-01243]; the German Research Foundation [DFG; ME 4667/2-1]; Hjärnfonden [FO2021-0112]; The Crafoord Foundation; Åke Wibergs Stiftelse [M19-0380], NMMP 2021 [V2021-2102]; the Albert Påhlsson Research Foundation; STINT [MG19-8469], Lund University; Canadian Institutes of Health Research [PJT-153269] and a Heart and Stroke Foundation of Ontario Mid-Career Investigator Award.

Sevoflurane-induced amnesia is associated with inhibition of hippocampal cell ensemble activity after learning.

General anesthesia could induce amnesia, however the mechanism remains unclear. We hypothesized that suppression of neuronal ensemble activity in the hippocampus by anesthesia during the post-learning period causes retrograde amnesia. To test this hypothesis, two experiments were conducted with sevoflurane anesthesia (2.5%, 30 min): a hippocampus-dependent memory task, the context pre-exposure facilitation effect (CPFE) procedure to measure memory function and in vivo calcium imaging to observe neural activity in hippocampal CA1 during context exploration and sevoflurane/home cage session. Sevoflurane treatment just after context pre-exposure session impaired the CPFE memory, suggesting sevoflurane induced retrograde amnesia. Calcium imaging showed sevoflurane treatment prevented neuronal activity in CA1. Further analysis of neuronal activity with non-negative matrix factorization, which extracts neural ensemble activity based on synchronous activity, showed that sevoflurane treatment reduced the reactivation of neuronal ensembles between during context exploration just before and one day after sevoflurane inhalation. These results suggest that sevoflurane treatment immediately after learning induces amnesia, resulting from suppression of reactivation of neuronal ensembles.

Long-Term Retrograde Global Amnesia Following Minor Trauma.

BACKGROUND Retrograde amnesia has several causes and may be the core concern in several conditions. When acute, somatic, and neurologic causes are excluded, along with substance use, a consideration of psychiatric disease is imminent. Here, we present a case with amnesia, where diagnostics and treatment were challenging due to severe psychiatric symptoms and course of the disease. CASE REPORT After a minor trauma while driving an electric scooter, a 41-year-old man lost all memories of the past 20 years. The patient was raised in a refugee camp, where he experienced traumatic events, and later came to Denmark and established family and work life. He had 1 prior contact with the psychiatric ward. After the incident, the patient was brought to the emergency room. The patient could not recognize his wife or children and believed he was 21 years old and living with his mother in the refugee camp. A full somatic and neurological workup was performed and no somatic or organic cause could explain the retrograde amnesia. He developed post-traumatic stress disorder (PTSD) and psychotic symptoms. Treatment consisted of a combination of psychoeducation, cognitive remediation, and medical treatment for psychotic symptoms and PTSD. CONCLUSIONS The diagnosis "prolonged delirium", "PTSD", and "dissociative amnesia" were considered. Psychiatric comorbidity and previous traumatic experiences might have contributed to the development of long-term amnesia, which eventually was considered to be dissociative. During 8 months, the patient slowly regained his memory. It is impossible to conclude with certainty whether the successful outcome was the result of psychological treatment, pharmacological treatment, the passing of time, or a mixture of these.

"This looks like a movie": a case report of post-surgical amnesia.

A 52-year-old male patient with a background of adaptive personality disorder was admitted for mitral valve repair and cardiac ablation for atrial fibrillation. He suffered intraoperative complications with severe mitral insufficiency that suffered ischemia.. Post-operatively, he demonstrated acute loss of retrograde autobiographical memory, prosopagnosia and a loss of public semantic memory. His CT scan was normal and MRI was not possible due to intra-cardiac leads. An initial diagnosis of hypoxic-ischemic encephalopathy was considered. A neuropsychological examination undertaken 20 days after his surgery showed a severe alteration of retrograde autobiographical memory, marked alteration of semantic knowledge and prosopagnosia. He demonstrated an average performance in tasks measuring constructional praxis, visuospatial ability, and executive functions. 34 days after surgery, and after a short nap, the patient "returns" to the day before admission and consequently recovers his memory. Repeat neuropsychological assessment demonstrated performance within the normal range across all previously tested domains. This sudden recovery of memory, together with a normal MRI, led to a rethinking of the diagnosis of dissociative amnesia. This case illustrates the long-standing discussion about the organic or functional origin of some memory disorders, in which, despite advances in neuroimaging techniques, it is still difficult to know their etiology .

Pathological Slow-Wave Activity and Impaired Working Memory Binding in Post-Traumatic Amnesia.

Associative binding is key to normal memory function and is transiently disrupted during periods of post-traumatic amnesia (PTA) following traumatic brain injury (TBI). Electrophysiological abnormalities, including low-frequency activity, are common following TBI. Here, we investigate associative memory binding during PTA and test the hypothesis that misbinding is caused by pathological slowing of brain activity disrupting cortical communication. Thirty acute moderate to severe TBI patients (25 males; 5 females) and 26 healthy controls (20 males; 6 females) were tested with a precision working memory paradigm requiring the association of object and location information. Electrophysiological effects of TBI were assessed using resting-state EEG in a subsample of 17 patients and 21 controls. PTA patients showed abnormalities in working memory function and made significantly more misbinding errors than patients who were not in PTA and controls. The distribution of localization responses was abnormally biased by the locations of nontarget items for patients in PTA, suggesting a specific impairment of object and location binding. Slow-wave activity was increased following TBI. Increases in the δ-α ratio indicative of an increase in low-frequency power specifically correlated with binding impairment in working memory. Connectivity changes in TBI did not correlate with binding impairment. Working memory and electrophysiological abnormalities normalized at 6 month follow-up. These results show that patients in PTA show high rates of misbinding that are associated with a pathological shift toward lower-frequency oscillations.SIGNIFICANCE STATEMENT How do we remember what was where? The mechanism by which information (e.g., object and location) is integrated in working memory is a central question for cognitive neuroscience. Following significant head injury, many patients will experience a period of post-traumatic amnesia (PTA) during which this associative binding is disrupted. This may be because of electrophysiological changes in the brain. Using a precision working memory test and resting-state EEG, we show that PTA patients demonstrate impaired binding ability, and this is associated with a shift toward slower-frequency activity on EEG. Abnormal EEG connectivity was observed but was not specific to PTA or binding ability. These findings contribute to both our mechanistic understanding of working memory binding and PTA pathophysiology.

The Retrograde Memory for News Events Test (RM-NET) and the relationship between news event memory and performance on standard neuropsychological tests.

Novel tests of semantic memory (SM)-for example, memory for news events (NE; news facts) or famous personalities-are useful for estimating the severity of retrograde amnesia. Individuals with mild cognitive impairment exhibit relatively intact SM/language on traditional neuropsychological tests but exhibit consistent impairment on novel tests of SM, suggesting novel SM tests are dissimilar from traditional SM tests. To identify the relationship between NE memory and traditional cognitive measures, older adults (N = 51) completed a traditional neuropsychological battery and the Retrograde Memory News Events Test (RM-NET; a new test that robustly measures NE memory across the adult life span with high temporal resolution), and the relationship between performance on these tests was examined. Total RM-NET scores were more closely aligned with episodic memory scores than SM scores. The strength of the association between NE scores and episodic memory scores decreased as the age of NE memory increased. Tests of news events appear to reflect performance on traditional tests of episodic memory rather than SM, especially when recent news events are tested.

Deriving testable hypotheses through an analogy between individual and collective memory.

The focus of this highly interdisciplinary essay is on an analogy between the formation of memory in individual brains and in collectives of individuals, and on the use of that analogy to derive two hypotheses. The first hypothesis involves the application of understanding of retrograde amnesia in individual brains, to the phenomenon of amnesia in collectives. The second hypothesis involves the application of observations of competition in the formation of collective memory, to memory formation in individuals. Evidence in support of both hypotheses is presented. This analogical reasoning leads to deeper understanding of memory on both individual and collective levels. It also raises many new questions-difficult questions that likely would not have arisen in the absence of the analogy.

Posttraumatic Amnesia: A Systematic Review and Meta-Analysis. Proposal for a New Severity Classification.

BACKGROUND: Posttraumatic amnesia (PTA) duration is used to predict outcome after traumatic brain injury (TBI): however, no meta-analysis exists. METHODS: A systematic review was performed following PRISMA reporting guidelines. The databases Scopus-1966, PubMed/MEDLINE, CINAHL, PsycINFO, and Embase were searched for relevant texts. Random effects meta-analysis derived pooled estimates of the odds ratio of outcomes of interest and sensitivity and specificity of PTA at different cutoffs, and subsequently a summary receiver operating curve was derived. PTA prediction of Glasgow Outcome Scale (GOS) and Glasgow Outcome Scale-Extended (GOSE) scores was assessed both qualitatively and quantitatively by pooled odds ratio regarding both a good outcome (GO: GOS-5 or GOSE-7/GOSE-8) and a severe disability outcome (SDO: GOS-3 or a GOSE-3/GOSE-4). Summary receiver operating curve analysis was performed in the prediction of composite of a moderate disability outcome (MDO: GOS-4 or GOSE-5/GOSE-6) and SDO. RESULTS: Twenty-four studies were included in qualitative synthesis, and 9 (12,386 patients; males, 64%-84%) in meta-analysis. The odds of a GO and SDO were significantly different between PTA >56 days and PTA <7 days (P = 0.04 and P = 0.03). PTA <7 days (mild TBI) excluded MDO/SDO and SDO alone with 87% and 90% sensitivity. PTA of 43-86 days (severe TBI) predicted MDO/SDO or SDO with 90%-96% and 80%-90% specificity. However, PTA of 7-42 days (moderate TBI) predicted MDO/SDO or SDO with only 38%-89% and 30%-80% specificity. CONCLUSIONS: PTA duration was reliable in predicting outcome when <7 days, and especially when >42 days but was often unreliable between 7 and 42 days duration.

Revisiting systems consolidation and the concept of consolidation.

For more than 50 years, knowledge of memory processes has been based on the consolidation hypothesis, which postulates that new memories require time to become stabilized. Two forms of the consolidation model exist. The Cellular Consolidation concept is based upon retrograde amnesia induced by amnesic treatments, the severity of which decreases as the learning to treatment increases over minutes or hours. In contrast, The Systems Consolidation model is based on post-training hippocampal lesions, which produce more severe retrograde amnesia when induced after days than after weeks. Except for the temporal parameters, Cellular and Systems Consolidation show many similarities. Here we propose that Systems consolidation, much as Cellular Consolidation (see Gisquet- Verrier and Riccio, 2018), can be explained in terms of a form of state-dependency. Accordingly, lesions of the hippocampus induce a change in the internal state of the animal, which disrupts retrieval processes. But the effect of contextual change is known to decrease with the length of the retention intervals, consistent with time-dependent retrograde amnesia. We provide evidence supporting this new view.

Aspects of Cognitive Impairment Associated with Agitated Behaviour during Post-traumatic Amnesia.

OBJECTIVES: Post-traumatic amnesia (PTA) is a transient period of recovery following traumatic brain injury (TBI) characterised by disorientation, amnesia, and cognitive disturbance. Agitation is common during PTA and presents as a barrier to patient outcome. A relationship between cognitive impairment and agitation has been observed. This prospective study aimed to examine the different aspects of cognition associated with agitation. METHODS: The sample comprised 82 participants (75.61% male) admitted to an inpatient rehabilitation hospital in PTA. All patients had sustained moderate to extremely severe brain injury as assessed using the Westmead Post-Traumatic Amnesia Scale (WPTAS) (mean duration = 42.30 days, SD = 35.10). Participants were assessed daily using the Agitated Behaviour Scale and WPTAS as part of routine clinical practice during PTA. The Confusion Assessment Protocol was administered two to three times per week until passed criterion was achieved (mean number assessments = 3.13, SD = 3.76). Multilevel mixed modelling was used to investigate the association between aspects of cognition and agitation using performance on items of mental control, orientation, memory free recall, memory recognition, vigilance, and auditory comprehension. RESULTS: Findings showed that improvement in orientation was significantly associated with lower agitation levels. A nonsignificant trend was observed between improved recognition memory and lower agitation. CONCLUSIONS: Current findings suggest that the presence of disorientation in PTA may interfere with a patient's ability to understand and engage with the environment, which in turn results in agitated behaviours. Interventions aimed at maximizing orientation may serve to minimize agitation during PTA.

Test-Retest Reliability of a Semi-Structured Interview to Aid in Pediatric Traumatic Brain Injury Diagnosis.

OBJECTIVE: Retrospective self-report is typically used for diagnosing previous pediatric traumatic brain injury (TBI). A new semi-structured interview instrument (New Mexico Assessment of Pediatric TBI; NewMAP TBI) investigated test-retest reliability for TBI characteristics in both the TBI that qualified for study inclusion and for lifetime history of TBI. METHOD: One-hundred and eight-four mTBI (aged 8-18), 156 matched healthy controls (HC), and their parents completed the NewMAP TBI within 11 days (subacute; SA) and 4 months (early chronic; EC) of injury, with a subset returning at 1 year (late chronic; LC). RESULTS: The test-retest reliability of common TBI characteristics [loss of consciousness (LOC), post-traumatic amnesia (PTA), retrograde amnesia, confusion/disorientation] and post-concussion symptoms (PCS) were examined across study visits. Aside from PTA, binary reporting (present/absent) for all TBI characteristics exhibited acceptable (≥0.60) test-retest reliability for both Qualifying and Remote TBIs across all three visits. In contrast, reliability for continuous data (exact duration) was generally unacceptable, with LOC and PCS meeting acceptable criteria at only half of the assessments. Transforming continuous self-report ratings into discrete categories based on injury severity resulted in acceptable reliability. Reliability was not strongly affected by the parent completing the NewMAP TBI. CONCLUSIONS: Categorical reporting of TBI characteristics in children and adolescents can aid clinicians in retrospectively obtaining reliable estimates of TBI severity up to a year post-injury. However, test-retest reliability is strongly impacted by the initial data distribution, selected statistical methods, and potentially by patient difficulty in distinguishing among conceptually similar medical concepts (i.e., PTA vs. confusion).

[Systematic revision of the neural bases of dissociative amnesia]. / Las bases neurales de la Amnesia Disociativa (AD): una revisión sistemática de la bibliografía.

INTRODUCTION: Dissociative amnesia (DA) is a retrograde amnesia characterized by an alteration in episodic memory. AIM: Establish the neural bases which underlie the development of dissociative amnesia. METHODS: Systematic and evaluative bibliographic review of qualitative type. RESULTS: The bibliography found suggested functional inhibition in the hippocampus, amygdala, temporal lobes, prefrontal cortex and thalamus. Also, hypoglycemia was observed in right cerebral cortex, at the fronto-temporal junction. An inhibition in the potential action P300 was also stated. CONCLUSIONS: There is enough evidence to say that dissociative amnesia is an objectifiable biologically based pathology. There is a need to review the current conceptualization of this syndrome and to establish new criteria that would allow us to distinguish DA from organic amnesias.

Retrograde amnesia of contextual fear conditioning: Evidence for retrosplenial cortex involvement in configural processing.

It has been suggested that contextual fear conditioning can be supported by either an elemental system, where individual features of the environment are associated with shock, or a configural system, where environmental features are bound together and associated with shock. Although the retrosplenial cortex (RSC) is known to be involved in contextual fear conditioning, it is not clear whether it contributes to the elemental or configural system. To isolate the role of the RSC in contextual fear conditioning, the current experiments examined the influence of RSC lesions on the context preexposure facilitation effect, a procedure known to produce conditioning to a configural representation of context. In Experiment 1, rats that were preexposed to the conditioning context froze more compared to rats that were not, replicating the context preexposure facilitation effect. Although pretraining lesions of the RSC had no impact on the context preexposure facilitation effect (Experiment 2a), posttraining lesions attenuated the effect (Experiment 2b), suggesting that the RSC normally contributes to a configural context representation. Retrohippocampal contributions to contextual fear conditioning are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).