Declarative Memory Impairment Research Articles

A Strategy for Allowing Earlier Diagnosis and Rigorous Evaluation of BACE1 Inhibitors in Preclinical Alzheimer's Disease.

Given continued failure of BACE1 inhibitor programs at symptomatic and prodromal stages of Alzheimer's disease (AD), clinical trials need to target the earlier preclinical stage. However, trial design is complex in this population with negative diagnosis of classical hippocampal amnesia on standard memory tests. Besides recent advances in brain imaging, electroencephalogram, and fluid-based biomarkers, new cognitive markers should be established for earlier diagnosis that can optimize recruitment to BACE1 inhibitor trials in presymptomatic AD. Notably, accelerated long-term forgetting (ALF) is emerging as a sensitive cognitive measure that can discriminate between asymptomatic individuals with high risks for developing AD and healthy controls. ALF is a form of declarative memory impairment characterized by increased forgetting rates over longer delays (days to months) despite normal storage within the standard delays of testing (20-60 min). Therefore, ALF may represent a harbinger of preclinical dementia and the impairment of systems memory consolidation, during which memory traces temporarily stored in the hippocampus become gradually integrated into cortical networks. This review provides an overview of the utility of ALF in a rational design of next-generation BACE1 inhibitor trials in preclinical AD. I explore potential mechanisms underlying ALF and relevant early-stage biomarkers useful for BACE1 inhibitor evaluation, including synaptic protein alterations, astrocytic dysregulation and neuron hyperactivity in the hippocampal-cortical network. Furthermore, given the physiological role of the isoform BACE2 as an AD-suppressor gene, I also discuss the possible association between the poor selectivity of BACE1 inhibitors and their side effects (e.g., cognitive worsening) in prior clinical trials.

Robotic assessment of sensorimotor and cognitive deficits in patients with temporal lobe epilepsy

ObjectiveIndividuals with temporal lobe epilepsy (TLE) frequently demonstrate impairments in executive function, working memory, and/or declarative memory. It is recommended that screening for cognitive impairment is undertaken in all people newly diagnosed with epilepsy. However, standard neuropsychological assessments are a limited resource and thus not available to all. Our study investigated the use of robotic technology (the Kinarm robot) for cognitive screening. Methods27 participants with TLE (17 left) underwent both a brief neuropsychological screening and a robotic (Kinarm) assessment. The degree of impairments and correlations between standardized scores from both approaches to assessments were analysed across different neurocognitive domains. Performance was compared between people with left and right TLE to look for laterality effects. Finally, the association between the duration of epilepsy and performance was assessed. ResultsAcross the 6 neurocognitive domains (attention, executive function, language, memory, motor and visuospatial) assessed by our neuropsychological screening, all showed scores that significantly correlated with Kinarm tasks assessing the same cognitive domains except language and memory that were not adequately assessed with Kinarm. Participants with right TLE performed worse on most tasks than those with left TLE, including both visuospatial (typically considered right hemisphere), and verbal memory and language tasks (typically considered left hemisphere). No correlations were found between the duration of epilepsy and either the neuropsychological screening or Kinarm assessment. SignificanceOur findings suggest that Kinarm may be a useful tool in screening for neurocognitive impairment in people with TLE. Further development may facilitate an easier and more rapid screening of cognition in people with epilepsy and distinguishing patterns of cognitive impairment.

Impact of “Golden” tomato juice on cognitive alterations in metabolic syndrome: Insights into behavioural and biochemical changes in a high-fat diet rat model

“Golden” tomato (GT) plays a protective role in metabolic dysfunction induced by High-Fat Diet (HFD). Our aim is to characterize the phytonutrient composition of the juice and explore the influence of GT, orally administered for one month, on cognitive impairment associated with Metabolic Syndrome (MetS) in male rats. We investigated reactivity, stress response and memory, together with brain neurotrophic/inflammatory signaling. Our data showed that HFD-induced functional modifications were ameliorated by GT nutritional supplementation. In particular, the behavioural reactivity improved in HFD/GT rats, that also showed a better performance in tests measuring anxiety and anhedonia. Furthermore, GT consumption rescued the declarative memory impairment. Lastly, GT supplementation counteracted HFD-induced brain alterations in PI3K\\Akt and MAPK/ERK signalling pathways. In conclusion, this study provides evidence of the importance of food supplementation with GT in the protection from neuroinflammation and cognitive alterations associated with MetS.

Keeping track of who knows what in multiparty conversation despite severe memory impairment

Language use has long been understood to be tailored to the intended addressee, a process termed audience design. Audience design is reflected in multiple aspects of language use, including adjustments based on the addressee's knowledge about the topic at hand. In group settings, audience design depends on representations of multiple individuals, each of whom may have different knowledge about the conversational topic. A central question, then, concerns how these representations are encoded and retrieved in multiparty conversation where successful conversation requires keeping track of who knows what. In the present research, we probe the biological memory systems that are involved in this process of multiparty audience design. We present the results of two experiments that compare language use in persons with bilateral hippocampal damage and severe declarative memory impairment (amnesia), and demographically matched neurotypical comparison participants. Participants played a game in which they discussed abstract images with one partner in conversation, and then discussed the images again with the same partner or with a new partner in a three-party conversation. Neurotypical participants' language use reflected newly formed representations of which partner was familiar with which images. Participants with amnesia showed evidence of partner-specific audience design in multiparty conversation but it was attenuated, especially when success required rapid alternations between representations of common ground. The findings suggest partial independence of the formation and use of partner-specific representations from the hippocampal-dependent declarative memory system and highlight the unique contributions of the declarative memory system to flexible and dynamic language use.

Impaired declarative memory consolidation in children with REM sleep-related obstructive sleep apnea.

We explored whether declarative memory consolidation is impaired in children with rapid eye movement sleep-related obstructive sleep apnea (REM-OSA) and investigated the correlation between memory consolidation and sleep-related respiratory parameters. Participants were children with habitual snoring aged 6-14 years and control children. Participants underwent polysomnography and declarative memory testing. Participants with snoring were categorized as primary snoring (PS), non-rapid eye movement sleep-related obstructive sleep apnea (NREM-OSA), stage-independent (SI)-OSA, and REM-OSA according to obstructive apnea-hypopnea index (OAHI), OAHI in REM sleep (OAHIREM), and OAHI in NREM sleep (OAHINREM). Declarative memory consolidation level was assessed by recall and recognition rates. There were 34 controls and 228 children with sleep-disordered breathing: 73 PS, 48 NREM-OSA, 59 SI-OSA, and 48 REM-OSA. Total arousal index was lower in the REM-OSA group than in the NREM-OSA group. In all groups, retest scores were higher than immediate test scores. Recall consolidation in PS, SI-OSA, and REM-OSA groups was lower than for controls and lower in REM-OSA than in NREM-OSA. There were no correlations between recall consolidation or recognition consolidation and OAHI, OAHINREM, oxygen desaturation index in REM sleep, total arousal index, or REM sleep percent. Recognition consolidation was negatively correlated with OAHIREM. Memory consolidation is impaired in children with REM-OSA compared with NREM-OSA and controls. There was no significant correlation between memory consolidation and OAHI, and recognition consolidation was negatively correlated with OAHIREM. It is important to pay attention to the OSA subtype in children. Tang Y, Yang C, Wang C, Wu Y, Xu Z, Ni X. Impaired declarative memory consolidation in children with REM sleep-related obstructive sleep apnea. J Clin Sleep Med. 2024;20(3):417-425.

The functional connectome of 3,4-methyldioxymethamphetamine-related declarative memory impairments.

The chronic intake of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") bears a strong risk for sustained declarative memory impairments. Although such memory deficits have been repeatedly reported, their neurofunctional origin remains elusive. Therefore, we here investigate the neuronal basis of altered declarative memory in recurrent MDMA users at the level of brain connectivity. We examined a group of 44 chronic MDMA users and 41 demographically matched controls. Declarative memory performance was assessed by the Rey Auditory Verbal Learning Test and a visual associative learning test. To uncover alterations in the whole brain connectome between groups, we employed a data-driven multi-voxel pattern analysis (MVPA) approach on participants' resting-state functional magnetic resonance imaging data. Recent MDMA use was confirmed by hair analyses. MDMA users showed lower performance in delayed recall across tasks compared to well-matched controls with moderate-to-strong effect sizes. MVPA revealed a large cluster located in the left postcentral gyrus of global connectivity differences between groups. Post hoc seed-based connectivity analyses with this cluster unraveled hypoconnectivity to temporal areas belonging to the auditory network and hyperconnectivity to dorsal parietal regions belonging to the dorsal attention network in MDMA users. Seed-based connectivity strength was associated with verbal memory performance in the whole sample as well as with MDMA intake patterns in the user group. Our findings suggest that functional underpinnings of MDMA-related memory impairments encompass altered patterns of multimodal sensory integration within auditory processing regions to a functional heteromodal connector hub, the left postcentral gyrus. In addition, hyperconnectivity in regions of a cognitive control network might indicate compensation for degraded sensory processing.

Declarative Memory Impairment and Emotional Bias in Recurrent Depression with a Seasonal Pattern: The Interplay between Emotion and Cognition in Seasonal Affective Disorder.

Seasonal Affective Disorder (SAD) is a subtype of Major Depressive Disorder (MDD) with a seasonal pattern. Although it is a pathological condition limited to specific seasons of the year, during the symptomatic period, patients may experience a significant impairment of well-being and daily quality of life as a result of the depressed mood, associated with other symptoms defined as atypical of MDD. While extensive evidence of memory deficits has been found in MDD, explicit memory impairments in SAD are insufficiently studied. This study aims to investigate the cognitive processing of emotional stimuli in women with SAD, in particular the interplay between emotions and declarative memory. One hundred and twenty young women, screened from an initial number of 1125 university students, were divided into two groups, an experimental one that included 60 medically untreated women affected by “winter type SAD” and a control group of 60 non-SAD women. Different subjects were randomly submitted to two types of audio–visual stories, neutral or arousal, and then their memory performances were analyzed by means of a free-recall test and a recognition memory test. In both the free-recall test (p < 0.008) and in the recognition memory test (p < 0.002), the SAD group showed impaired memory performances. Taken together, our novel key findings suggest that SAD is characterized by impairment in declarative memory and attentional bias for emotional negative stimuli.

Evidence of Audience Design in Amnesia: Adaptation in Gesture but Not Speech.

Speakers design communication for their audience, providing more information in both speech and gesture when their listener is naïve to the topic. We test whether the hippocampal declarative memory system contributes to multimodal audience design. The hippocampus, while traditionally linked to episodic and relational memory, has also been linked to the ability to imagine the mental states of others and use language flexibly. We examined the speech and gesture use of four patients with hippocampal amnesia when describing how to complete everyday tasks (e.g., how to tie a shoe) to an imagined child listener and an adult listener. Although patients with amnesia did not increase their total number of words and instructional steps for the child listener, they did produce representational gestures at significantly higher rates for the imagined child compared to the adult listener. They also gestured at similar frequencies to neurotypical peers, suggesting that hand gesture can be a meaningful communicative resource, even in the case of severe declarative memory impairment. We discuss the contributions of multiple memory systems to multimodal audience design and the potential of gesture to act as a window into the social cognitive processes of individuals with neurologic disorders.

Revisiting the Role of the Medial Temporal Lobe in Motor Learning.

Classic taxonomies of memory distinguish explicit and implicit memory systems, placing motor skills squarely in the latter branch. This assertion is in part a consequence of foundational discoveries showing significant motor learning in amnesics. Those findings suggest that declarative memory processes in the medial temporal lobe (MTL) do not contribute to motor learning. Here, we revisit this issue, testing an individual (L. S. J.) with severe MTL damage on four motor learning tasks and comparing her performance to age-matched controls. Consistent with previous findings in amnesics, we observed that L. S. J. could improve motor performance despite having significantly impaired declarative memory. However, she tended to perform poorly relative to age-matched controls, with deficits apparently related to flexible action selection. Further supporting an action selection deficit, L. S. J. fully failed to learn a task that required the acquisition of arbitrary action-outcome associations. We thus propose a modest revision to the classic taxonomic model: Although MTL-dependent memory processes are not necessary for some motor learning to occur, they play a significant role in the acquisition, implementation, and retrieval of action selection strategies. These findings have implications for our understanding of the neural correlates of motor learning, the psychological mechanisms of skill, and the theory of multiple memory systems.

Future and past autobiographical memory in persons with HIV disease.

Objective: While HIV disease is associated with impairment in declarative memory, the ability of people with HIV (PWH) to describe past and future autobiographical events is not known. Method: Participants included 63 PWH and 28 seronegative individuals ages 50-78 who completed standardized neurocognitive and everyday functioning assessments. Participants described four events from the recent past and four imagined events in the near future, details from which were classified as internal or external to the main event. Result: PWH produced fewer autobiographical details with small-to-medium effect sizes but did not differ from seronegative participants in meta-cognitive ratings of their performance. Performance of the study groups did not vary across past or future probes or internal versus external details; however, within the entire sample, past events were described in greater detail than future events, and more external than internal details were produced. Within the PWH group, the production of fewer internal details for future events was moderately associated with poorer prospective memory, executive dysfunction, and errors on a laboratory-based task of medication management. Conclusion: Older PWH may experience difficulty generating autobiographical details from the past and simulated events in the future, which may be related to executive dyscontrol of memory processes. Future studies might examine the role of future thinking in health behaviors such as medication adherence and retention in healthcare among PWH. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

TDMQ20, a Specific Copper Chelator, Reduces Memory Impairments in Alzheimer's Disease Mouse Models.

Besides targeting amyloid or tau metabolisms, regulation of redox metal ions is a recognized therapeutic target for Alzheimer's disease (AD). Based on the bioinorganic chemistry of copper, we designed specific chelators of copper(II) (TDMQs) insight to regulate copper homeostasis in the brain and to inhibit the deleterious oxidative stress catalyzed by copper-amyloid complexes. An oral treatment by TDMQ20 was able to fully reverse the cognitive and behavioral impairment in three different murine models, two nontransgenic models mimicking the early stage of AD and a transgenic model representing a more advanced stage of AD. To our knowledge, such a comparative study using the same molecule has never been performed. Regular C57BL/6 mice received a single injection of human Cu-Aβ1-42 in the lateral ventricles (icv-CuAβ) or in the hippocampus (hippo-CuAβ). In both cases, mice developed a cognitive impairment similar to that of transgenic 5XFAD mice. Oral administration of TDMQ20 to icv-CuAβ or hippo-CuAβ mice within a 16-day period resulted in a significant improvement of the cognitive status. The 3-month treatment of transgenic 5XFAD mice with TDMQ20 also resulted in behavioral improvements. The consistent positive pharmacological results obtained using these different AD models correlate well with previously obtained physicochemical data of TDMQ20. The short-term novel object recognition (NOR) test was found particularly relevant to evaluate the rescue of declarative memory impairment. TDMQ20 was also able to reduce the oxidative stress in the mouse cortex. Due to its reliability and facile use, the hippo-CuAβ model can be considered as a robust nontransgenic model to evaluate the activity of potential drugs on the early stages of memory deficits.

An fMRI investigation of neural activation predicting memory formation in children with fetal alcohol spectrum disorders

Prenatal alcohol exposure (PAE) is associated with physical anomalies, growth restriction, and a range of neurobehavioral deficits. Although declarative memory impairment has been documented extensively in individuals with fetal alcohol spectrum disorders (FASD), this cognitive process has been examined in only one functional magnetic resonance imaging (fMRI) study, and mechanisms underlying this impairment are not well understood. We used an event-related fMRI design to examine neural activations during visual scene encoding that predict subsequent scene memory in 51 right-handed children (age range = 10–14 years, M = 11.3, SD = 1.3) whose mothers had been recruited and interviewed prospectively about their alcohol use during pregnancy. Following examination by expert dysmorphologists, children were assigned to one of three FASD diagnostic groups: FAS/PFAS (nFAS = 7; nPFAS = 4), nonsyndromal heavily exposed (HE; n = 14), and Controls (n = 26). Subsequent memory was assessed in a post-scan recognition test, and subsequent memory activations were examined by contrasting activations during encoding of scenes that were subsequently remembered (hits) to those for incorrectly judged as ‘new’ (misses). Recognition accuracy did not differ between groups. Pooled across groups, we observed extensive bilateral subsequent memory effects in regions including the hippocampal formation, posterior parietal cortex, and occipital cortex—a pattern consistent with previous similar studies of typically developing children. Critically, in the group of children with FAS or PFAS, we observed activations in several additional regions compared to HE and Control groups. Given the absence of between-group differences in recognition accuracy, these data suggest that in achieving similar memory compared to children in the HE and Control groups, children with FAS and PFAS recruit more extensive neural resources to achieve successful memory formation.

Klüver‐Bucy syndrome due to stroke in the left temporal lobe

AbstractBackgroundKlüver‐Bucy syndrome (KBS) comprises: 1) hyperorality, 2) hypermetamorphosis, 3) hypersexuality, 4) eating disorder, 5) placidity, 6) visual agnosia (psychic blindness) and 7) amnesia (at least three components are described as partial KBS). The classic description involves bilateral injuries to the anterior temporal lobes, but it has been reported that unilateral lesions can also lead to KBS.MethodCase report and analyses of MR Images (T1, Flair and Tractography) of a patient presenting partial KBS due to stroke in the left temporal lobe.ResultMale patient, 69 years‐old, with cognitive deficits that have begun after a left frontotemporal stroke in 2003, with remarkable changes in the temporal pole. In the first months after the stroke, he used to get lost when out of home and had difficulty remembering names and recognizing well known persons due to psychic blindness. During the next years, the patient developed impairment in declarative memory, but preserved visuospatial skills (many times coming to the medical appointments alone, using public transportation). Over time, he developed binge eating (once eating 1 kilogram of cheese, for instance), inability to deal with money (unnecessary loans in banks) and bizarre sexual behavior (such as excessive addiction to porn movies, public masturbation, flirting with women in his neighborhood, and an episode of inappropriate sexual behavior with his daughter‐in‐law). The patient still resists taking bath and changing clothes.ConclusionThe exact anatomic basis of KBS is still controversial. What is remarkable is the main role of the amygdala in the syndrome. However, periamygdalar lesions can cause disconnection syndromes and damage the limbic network that involves the uncus, the hippocampus, the insular cortex, orbitofrontal and cingulate gyri. Patients with KBS can mimic behavioral variant frontotemporal lobar degeneration (bvFTLD) – particularly regarding eating and sexual disorders, probably due to the connections between the amygdala and the orbitofrontal gyri. The integrity of these two regions and their connections probably play an important role in emotional continence, modulating basic desires in the human species. Lesions in the uncinate fasciculus can predispose to KBS. Our patient exhibits lack of fibers connecting temporal lobe and orbitofrontal cortex showed in the tractography.

Age-related impairment of declarative memory: linking memorization of temporal associations to GluN2B redistribution in dorsal CA1.

GluN2B subunits of NMDA receptors have been proposed as a target for treating age‐related memory decline. They are indeed considered as crucial for hippocampal synaptic plasticity and hippocampus‐dependent memory formation, which are both altered in aging. Because a synaptic enrichment in GluN2B is associated with hippocampal LTP in vitro, a similar mechanism is expected to occur during memory formation. We show instead that a reduction of GluN2B synaptic localization induced by a single‐session learning in dorsal CA1 apical dendrites is predictive of efficient memorization of a temporal association. Furthermore, synaptic accumulation of GluN2B, rather than insufficient synaptic localization of these subunits, is causally involved in the age‐related impairment of memory. These challenging data identify extra‐synaptic redistribution of GluN2B‐containing NMDAR induced by learning as a molecular signature of memory formation and indicate that modulating GluN2B synaptic localization might represent a useful therapeutic strategy in cognitive aging.

Environmental Enrichment During Adolescence Mitigates Cognitive Deficits and Alcohol Vulnerability due to Continuous and Intermittent Perinatal Alcohol Exposure in Adult Rats.

Perinatal alcohol exposure affects ontogenic neurodevelopment, causing physical and functional long-term abnormalities with limited treatment options. This study investigated long-term consequences of continuous and intermittent maternal alcohol drinking on behavioral readouts of cognitive function and alcohol vulnerability in the offspring. The effects of environmental enrichment (EE) during adolescence were also evaluated. Female rats underwent continuous alcohol drinking (CAD)—or intermittent alcohol drinking paradigm (IAD), along pregestation, gestation, and lactation periods—equivalent to the whole gestational period in humans. Male offspring were reared in standard conditions or EE until adulthood and were then assessed for declarative memory in the novel object recognition test; spatial learning, cognitive flexibility, and reference memory in the Morris water maze (MWM); alcohol consumption and relapse by a two-bottle choice paradigm. Our data show that perinatal CAD decreased locomotor activity, exploratory behavior, and declarative memory with respect to controls, whereas perinatal IAD displayed impaired declarative memory and spatial learning and memory. Moreover, both perinatal alcohol-exposed offspring showed higher vulnerability to alcohol consummatory behavior than controls, albeit perinatal IAD rats showed a greater alcohol consumption and relapse behavior with respect to perinatal-CAD progeny. EE ameliorated declarative memory in perinatal CAD, while it mitigated spatial learning and reference memory impairment in perinatal-IAD progeny. In addition, EE decreased vulnerability to alcohol in both control and perinatal alcohol-exposed rats. Maternal alcohol consumption produces drinking pattern-related long-term consequences on cognition and vulnerability to alcohol in the offspring. However, increased positive environmental stimuli during adolescence may curtail the detrimental effects of developmental alcohol exposure.

Fetal Bisphenol-A Induced Changes in Murine Behavior and Brain Gene Expression Persisted in Adult-aged Offspring.

In utero Bisphenol A (BPA) exposure has been linked to many deficits during brain development, including sexual differentiation, behavior, and motor coordination. Yet, how BPA induces these disorders and whether its effects are long lasting are largely unknown. In this study, using a mouse model, we demonstrated that in utero exposure to an environmentally relevant dose of BPA induced locomotor deficits, anxiety-like behavior, and declarative memory impairments that persisted into old age (18 months). Compared to the control animals, the BPA-exposed mice had a significant decrease in locomotor activity, exploratory tendencies, and long-term memory, and an increase in anxiety. The global brain gene expression profile was altered permanently by BPA treatment and showed regional and sexual differences. The BPA-treated male mice had more changes in the hippocampus, while female mice experienced more changes in the cortex. Overall, we demonstrate that in utero exposure to BPA induces permanent changes in brain gene expression in a region-specific and sex-specific manner, including a significant decrease in locomotor activity, learning ability, long-term memory, and an increase in anxiety. Fetal/early life exposures permanently affect neurobehavioral functions that deteriorate with age; BPA exposure may compound the effects of aging.

Time-Dependent Impairment of Fear Conditioning and Associated Brain Regions After Pilocarpine-Induced Status Epilepticus.

Our study aimed to demonstrate time-dependent declarative memory changes and its associated brain regions after status epilepticus (SE) using structural imaging techniques and machine learning methods. Pilocarpine was administrated to establish the SE model. At four different time points after SE (1, 2, 3, and 4 months, respectively), rats were subjected to structural imaging acquisition as well as contextual fear conditioning for the measurement of brain structural changes and declarative memory. Voxel-based morphometry (VBM) analysis were performed. Those significantly different regions were selected as features for training support vector machine (SVM). A linear kernel was chosen for regression of declarative memory. Leave-one-out cross-validation was applied to ensure generalization. Our results showed that the pilocarpine groups displayed the most severely impaired declarative memory at 2 months after SE and improved afterward, but failed to recover to the normal condition at 4 months after SE. The pilocarpine groups showed lower gray matter volumes and larger cerebrospinal fluid (CSF) volumes. After controlling for the total brain volumes, ANOVA demonstrated gray matter volume changes in the CA1 subfield of the hippocampus, primary somatosensory cortex, entorhinal cortex, etc. The combination of VBM and SVM identifies the somatosensory cortex and entorhinal cortex as the correlated brain regions for declarative memory dysfunctions after SE. Our study indicates that compensational mechanisms might be triggered to help with the recovery of memory functions after SE. Structural changes of the somatosensory cortex and entorhinal cortex might be involved in memory impairment after SE.

Subjective working memory predicts objective memory in cognitively normal aging: a HUNT study

BackgroundRecent studies have shown that subjective memory is multi-, rather than uni-dimensional, in line with the results of objective memory tests. The purpose of this study was to investigate whether there is an association between aspects of memory measured by the subjective Meta-Memory Questionnaire (MMQ) and aspects of memory measured by the objective Wechsler Memory Scale-III (WMS-III) and Wechsler Adult Intelligence Scale-III (WAIS-III) tests in cognitively normal older adults.MethodThe study subjects (n = 106) were cognitively normal, were aged 57–89 years and had participated in the third wave of the North-Trøndelag Health survey (HUNT3). All subjects had completed the MMQ, the WMS-III and the WAIS-III. Previous results from the MMQ (measured as the total MMQ score; the Component I score, related to long-term explicit declarative memory; and the Component II score, related to working/short-term memory) were compared with objective results from WMS-III (Logical Memory) and WAIS-III (Vocabulary and Letter-Number Sequencing) subtests. We conducted linear regression analyses with each objective memory test result as the dependent variable, and subjective memory measures and demographics as independent variables, as well as analyses of MMQ items vs. objective memory.ResultsSubjective working memory impairment (Component II) was significant related to poor performance in objective episodic memory, according to correlation and regression analyses with demographic covariates. In contrast, ratings of impaired subjective declarative memory (Component I) were not related to poor objective memory performance.ConclusionsSpecific aspects of subjective memory related differentially to performance in specific objective memory tests. Clinicians and researchers might consider targeting working memory aspects of subjective memory tests, when seeking an estimate of objective memory performance.

Declarative Memory and Structural Language Impairment in Autistic Children and Adolescents.

Two experiments tested the hypothesis that a plausible contributory factor of structural language impairment in Autism Spectrum Disorder (ASD) is impaired declarative memory. We hypothesized that familiarity and recollection (subserving semantic and episodic memory, respectively) are both impaired in autistic individuals with clinically significant language impairment and learning disability (ASDLI/LD ); whereas recollection is selectively impaired in autistic individuals with typical language (ASDTL ). Teenagers with ASDLI/LD (n = 19) and primary school age children with ASDTL (n = 26) were compared with teenagers with learning disability (LD) (n = 26) without autism, and primary school aged typically developing (TD) children (n = 32). Both experiments provided strong support for the hypothesized links between declarative memory processes and lexical-semantic facets of language in the two autistic groups, but not in the TD group. Additional findings of interest were that declarative memory processes and lexical-semantic knowledge were also linked in the LD group and that the ASD groups-and to a lesser extent the LD group-may have compensated for declarative memory impairments using spared visual-perceptual abilities, a finding with potential educational implications. Relative difficulties with familiarity and recollection in ASDLI/LD and LD may help explain structural language impairment, as investigated here, but also the broader learning disabilities found in these populations. Autism Res 2020. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2020, 13: 1947-1958. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Language impairment and learning disability affect 45% of the autistic population yet the factors that may be contributing to them is remarkably under-researched. To date there are no explanations of the lexical semantic (word meaning) abnormalities observed in ASD. We found that declarative memory is associated with lexical semantic knowledge in autism and learning disability but not in typical development. Difficulties with declarative memory may also be compensated for using visual-perceptual abilities by autistic and learning-disabled adolescents, which has positive implications for educationalists.

CHANGES IN OPEN FIELD BEHAVIOR AND DECLARATIVE MEMORY IN “DEPRESSIVE” RATS WITH HIGH IMMOBILITY AND DECREASED LEVEL OF BRAIN MONOAMINES

INTRODUCTION Changes in some forms of motivational-emotional behavior, learning and memory are thought to be characteristic for major depressive disease. However, results existing until today about the character of changes in motivational-emotional and exploratory behavior as well as character of disorders in declarative memory, accompanying major depressive disease, are not unambiguous. Therefore, studying them in animal models of depression is very topical and important. METHODS Experiments were conducted on adult white wild rats (with 250-300 g weight). “Depressive” and “non- depressive” rats were selected according to the level of immobility in forced swim test. Rats with low level of immobility, “non-depressive” rats, constituted control group and rats with high level of immobility, “depressive” rats, constituted the experimental group (10 rats in each). Changes of motivational-emotional and exploratory behavior were studied in open field test. The changes of learning and memory were studied in the fear motivated one trial passive avoidance test considered as the declarative memory test. Experiments were carried out on “non-depressive”, control and “depressive”, experimental groups (10 rats in each). Obtained results were processed statistically by Student’s t-test. RESULTS Sharp decrease in locomotion was found in rats with high level of immobility. It was manifested in a significant decrease of the number of crossed squares. The quantitative indices of vertical activity, vertical standings, head risings, were also sharply decreased. Fear reaction was considerably increased in “depressive” rats, manifested in the significant decrease of the number of entering in the center of open field and grooming and sharp increase in defecation rate. Investigation of the changes of learning and memory in the passive avoidance test has shown that the latency of entering from the light into dark section of passive avoidance camera, in the learning session, was sharply increased in “depressive” rats. They revealed an impaired ability to evaluate the level of danger coming from the brightly illuminated open area and therefore they do not hurry to escape from the dangerous section. The difference between “depressive” and “non-depressive” rats was maintained even after 24 hours from receiving a painful stimulation. In particular, the animals of control group remember that they have received a painful stimulation in dark section during learning session and do not enter there during testing session, whereas the experimental animals with considerable delay but still enter in the dark section during testing session, therefore, they show significant impairment of declarative memory in passive avoidance task. CONCLUSIONS Locomotor and exploratory behavior are impaired and fear motivation is increased in the open field in “depressive” rats with high immobility and low level of monoamines content in the brain. Learning and memory in one of the tests of declarative memory, so called passive avoidance task, is disturbed.