Subjective memory complaints in young people; their relationship withobjective cognitive performance and the role of neuroticism / Quejas subjetivas de memoria en jóvenes; su relación con el rendimiento cognitivo objetivo y el papel del neuroticismo

Las percepciones de olvidos recurrentes o episodios de distracción en la vida diaria se denominan quejas subjetivas de memoria (QSM). Su naturaleza se ha estudiado ampliamente en adultos mayores, pero su importancia y relación con el rendimiento neurocognitivo no se han abordado por completo en adultos más jóvenes. Se han sugerido algunos rasgos psicológicos como posibles moderadores de la asociación entre el rendimiento de la memoria objetiva y subjetiva. El primer objetivo de este estudio fue analizar la correspondencia entre la percepción objetiva y subjetiva de los fallos de memoria en jóvenes. En segundo lugar, estudiamos si el rasgo psicológico del neuroticismo podría estar influyendo en esta relación. Para ello, medimos QSM, diferentes dominios cognitivos (memoria episódica y de trabajo y funciones ejecutivas) y neuroticismo en 80 hombres y mujeres jóvenes. Los resultados mostraron que solo la memoria episódica inmediata estaba estadísticamente relacionada con los QSM. Curiosamente, las relaciones negativas entre el rendimiento de la memoria objetiva y subjetiva solo aparecieron en participantes con mayor neuroticismo. Por lo tanto, las quejas de memoria reportadas por los jóvenes podrían reflejar un peor rendimiento de la memoria episódica inmediata, mientras que el neuroticismo jugaría un papel principal en la asociación entre los déficits de memoria y las QSM. Este estudio proporciona datos que pueden ayudar a comprender mejor las QSM en los jóvenes.(AU)

Perceptions of recurrent forgetfulness or episodes of distraction in daily life are referred to as subjective memory complaints (SMCs). Their nature has been extensively studied in older adults, but their significance and relationship with neurocognitive performance have not been fully ad-dressed in younger adults. Some psychological traits have been suggested as possible moderators of the association between objective and subjective memory performance. The first aim of this study was to analyze the corre-spondence between the objective and subjective perception of memory failures in young people. Second, we studied whether the psychological trait of neuroticism could be influencing this relationship. Todo this, we measured SMCs, different cognitive domains (episodic and working memory and executive functions), and neuroticism in 80 young men and women. Results showed that only immediate episodic memory was statisti-cally related to SMCs. Interestingly, the negative relationships between ob-jective and subjective memory performance only appeared in participants with higher neuroticism. Thus, memory complaints reported by young people could reflect poorer immediate episodic memory performance, whereas neuroticism would play a main role in the association between memory deficits and SMCs. This study provides data that can help to bet-ter understand SMCs in young people.(AU)

Learning and Memory Impairments With Attention-Deficit/Hyperactivity Disorder.

ADHD is a common chronic neurodevelopmental disorder and is characterized by persistent inattention, hyperactivity, impulsivity and are often accompanied by learning and memory impairment. Great evidence has shown that learning and memory impairment of ADHD plays an important role in its executive function deficits, which seriously affects the development of academic, cognitive and daily social skills and will cause a serious burden on families and society. With the increasing attention paid to learning and memory impairment in ADHD, relevant research is gradually increasing. In this article, we will present the current research results of learning and memory impairment in ADHD from the following aspects. Firstly, the animal models of ADHD, which display the core symptoms of ADHD as well as with learning and memory impairment. Secondly, the molecular mechanism of has explored, including some neurotransmitters, receptors, RNAs, etc. Thirdly, the susceptibility gene of ADHD related to the learning and impairment in order to have a more comprehensive understanding of the pathogenesis. Key words: Learning and memory, ADHD, Review.

An Exploration of the Memory Performance in Older Adult Hearing Aid Users on the Integrated Digit-in-Noise Test.

This study aimed to preliminarily investigate the associations between performance on the integrated Digit-in-Noise Test (iDIN) and performance on measures of general cognition and working memory (WM). The study recruited 81 older adult hearing aid users between 60 and 95 years of age with bilateral moderate to severe hearing loss. The Chinese version of the Montreal Cognitive Assessment Basic (MoCA-BC) was used to screen older adults for mild cognitive impairment. Speech reception thresholds (SRTs) were measured using 2- to 5-digit sequences of the Mandarin iDIN. The differences in SRT between five-digit and two-digit sequences (SRT5-2), and between five-digit and three-digit sequences (SRT5-3), were used as indicators of memory performance. The results were compared to those from the Digit Span Test and Corsi Blocks Tapping Test, which evaluate WM and attention capacity. SRT5-2 and SRT5-3 demonstrated significant correlations with the three cognitive function tests (rs ranging from -.705 to -.528). Furthermore, SRT5-2 and SRT5-3 were significantly higher in participants who failed the MoCA-BC screening compared to those who passed. The findings show associations between performance on the iDIN and performance on memory tests. However, further validation and exploration are needed to fully establish its effectiveness and efficacy.

Virtual reality-based training may improve visual memory and some aspects of sustained attention among healthy older adults - preliminary results of a randomized controlled study.

BACKGROUND/AIMS: Older age and cognitive inactivity have been associated with cognitive impairment, which in turn is linked to economic and societal burdens due to the high costs of care, especially for care homes and informal care. Emerging non-pharmacological interventions using new technologies, such as virtual reality (VR) delivered on a head-mounted display (HMD), might offer an alternative to maintain or improve cognition. The study aimed to evaluate the efficacy and safety of a VR-based Digital Therapeutics application for improving cognitive functions among healthy older adults. METHODS: Seventy-two healthy seniors (experimental group N = 35, control group N = 37), aged 65-85 years, were recruited by the Medical University of Lodz (Poland). Participants were randomly allocated to the experimental group (a VR-based cognitive training which consists of a warm-up module and three tasks, including one-back and dual-N-back) or to the control group (a regular VR headset app only showing nature videos). The exercises are performed in different 360-degree natural environments while listening to a preferred music genre and delivered on a head-mounted display (HMD). The 12-week intervention of 12 min was delivered at least three times per week (36 sessions). Compliance and performance were followed through a web-based application. Primary outcomes included attention and working memory (CNS-Vital Signs computerized cognitive battery). Secondary outcomes comprised other cognitive domains. Mixed linear models were constructed to elucidate the difference in pre- and post-intervention measures between the experimental and control groups. RESULTS: The users performed, on average, 39.8 sessions (range 1-100), and 60% performed more than 36 sessions. The experimental group achieved higher scores in the visual memory module (B = 7.767, p = 0.011) and in the one-back continuous performance test (in terms of correct responses: B = 2.057, p = 0.003 and omission errors: B = -1.950, p = 0.007) than the control group in the post-test assessment. The results were independent of participants' sex, age, and years of education. The differences in CNS Vital Signs' global score, working memory, executive function, reaction time, processing speed, simple and complex attention, verbal memory, cognitive flexibility, motor speed, and psychomotor speed were not statistically significant. CONCLUSIONS: VR-based cognitive training may prove to be a valuable, efficacious, and well-received tool in terms of improving visual memory and some aspect of sustainability of attention among healthy older adults. This is a preliminary analysis based on part of the obtained results to that point. Final conclusions will be drawn after the analysis of the target sample size. TRIAL REGISTRATION: Clinicaltrials.gov ID NCT05369897.

The effect of misophonia on cognitive and social judgments.

Misophonia, a heightened aversion to certain sounds, turns common cognitive and social exercises (e.g., paying attention during a lecture near a pen-clicking classmate, coexisting at the dinner table with a food-chomping relative) into challenging endeavors. How does exposure to triggering sounds impact cognitive and social judgments? We investigated this question in a sample of 65 participants (26 misophonia, 39 control) from the general population. In Phase 1, participants saw faces paired with auditory stimuli while completing a gender judgment task, then reported sound discomfort and identification. In Phase 2, participants saw these same faces with novel ones and reported face likeability and memory. For both oral and non-oral triggers, misophonic participants gave higher discomfort ratings than controls did-especially when identification was correct-and performed slower on the gender judgment. Misophonic participants rated lower likeability than controls did for faces they remembered with high discomfort sounds, and face memory was worse overall for faces originally paired with high discomfort sounds. Altogether, these results suggest that misophonic individuals show impairments on social and cognitive judgments if they must endure discomforting sounds. This experiment helps us better understand the day-to-day impact of misophonia and encourages usage of individualized triggers in future studies.

Counterfactual thinking induces different neural patterns of memory modification in anxious individuals.

Episodic counterfactual thinking (eCFT) is the process of mentally simulating alternate versions of experiences, which confers new phenomenological properties to the original memory and may be a useful therapeutic target for trait anxiety. However, it remains unclear how the neural representations of a memory change during eCFT. We hypothesized that eCFT-induced memory modification is associated with changes to the neural pattern of a memory primarily within the default mode network, moderated by dispositional anxiety levels. We tested this proposal by examining the representational dynamics of eCFT for 39 participants varying in trait anxiety. During eCFT, lateral parietal regions showed progressively more distinct activity patterns, whereas medial frontal neural activity patterns became more similar to those of the original memory. Neural pattern similarity in many default mode network regions was moderated by trait anxiety, where highly anxious individuals exhibited more generalized representations for upward eCFT (better counterfactual outcomes), but more distinct representations for downward eCFT (worse counterfactual outcomes). Our findings illustrate the efficacy of examining eCFT-based memory modification via neural pattern similarity, as well as the intricate interplay between trait anxiety and eCFT generation.

Choline Metabolites Reverse Differentially the Habituation Deficit and Elevated Memory of Tau Null Drosophila.

Impaired neuronal plasticity and cognitive decline are cardinal features of Alzheimer's disease and related Tauopathies. Aberrantly modified Tau protein and neurotransmitter imbalance, predominantly involving acetylcholine, have been linked to these symptoms. In Drosophila, we have shown that dTau loss specifically enhances associative long-term olfactory memory, impairs foot shock habituation, and deregulates proteins involved in the regulation of neurotransmitter levels, particularly acetylcholine. Interestingly, upon choline treatment, the habituation and memory performance of mutants are restored to that of control flies. Based on these surprising results, we decided to use our well-established genetic model to understand how habituation deficits and memory performance correlate with different aspects of choline physiology as an essential component of the neurotransmitter acetylcholine, the lipid phosphatidylcholine, and the osmoregulator betaine. The results revealed that the two observed phenotypes are reversed by different choline metabolites, implying that they are governed by different underlying mechanisms. This work can contribute to a broader knowledge about the physiologic function of Tau, which may be translated into understanding the mechanisms of Tauopathies.

Postovulatory Aging of Mouse Oocytes Impairs Offspring Behavior by Causing Oxidative Stress and Damaging Mitochondria.

Information on long-term effects of postovulatory oocyte aging (POA) on offspring is limited. Whether POA affects offspring by causing oxidative stress (OS) and mitochondrial damage is unknown. Here, in vivo-aged (IVA) mouse oocytes were collected 9 h after ovulation, while in vitro-aged (ITA) oocytes were obtained by culturing freshly ovulated oocytes for 9 h in media with low, moderate, or high antioxidant potential. Oocytes were fertilized in vitro and blastocysts transferred to produce F1 offspring. F1 mice were mated with naturally bred mice to generate F2 offspring. Both IVA and the ITA groups in low antioxidant medium showed significantly increased anxiety-like behavior and impaired spatial and fear learning/memory and hippocampal expression of anxiolytic and learning/memory-beneficial genes in both male and female F1 offspring. Furthermore, the aging in both groups increased OS and impaired mitochondrial function in oocytes, blastocysts, and hippocampus of F1 offspring; however, it did not affect the behavior of F2 offspring. It is concluded that POA caused OS and damaged mitochondria in aged oocytes, leading to defects in anxiety-like behavior and learning/memory of F1 offspring. Thus, POA is a crucial factor that causes psychological problems in offspring, and antioxidant measures may be taken to ameliorate the detrimental effects of POA on offspring.

Eye movement intervention facilitates concurrent perception and memory processing.

A widely used psychotherapeutic treatment for post-traumatic stress disorder (PTSD) involves performing bilateral eye movement (EM) during trauma memory retrieval. However, how this treatment-described as eye movement desensitization and reprocessing (EMDR)-alleviates trauma-related symptoms is unclear. While conventional theories suggest that bilateral EM interferes with concurrently retrieved trauma memories by taxing the limited working memory resources, here, we propose that bilateral EM actually facilitates information processing. In two EEG experiments, we replicated the bilateral EM procedure of EMDR, having participants engaging in continuous bilateral EM or receiving bilateral sensory stimulation (BS) as a control while retrieving short- or long-term memory. During EM or BS, we presented bystander images or memory cues to probe neural representations of perceptual and memory information. Multivariate pattern analysis of the EEG signals revealed that bilateral EM enhanced neural representations of simultaneously processed perceptual and memory information. This enhancement was accompanied by heightened visual responses and increased neural excitability in the occipital region. Furthermore, bilateral EM increased information transmission from the occipital to the frontoparietal region, indicating facilitated information transition from low-level perceptual representation to high-level memory representation. These findings argue for theories that emphasize information facilitation rather than disruption in the EMDR treatment.

Children exhibit superior memory for attended but outdated information compared to adults.

Research on the development of cognitive selectivity predominantly focuses on attentional selection. The present study explores another facet of cognitive selectivity-memory selection-by examining the ability to filter attended yet outdated information in young children and adults. Across five experiments involving 130 children and 130 adults, participants are instructed to use specific information to complete a task, and then unexpectedly asked to report this information in a surprise test. The results consistently demonstrate a developmental reversal-like phenomenon, with children outperforming adults in reporting this kind of attended yet outdated information. Furthermore, we provide evidence against the idea that the results are due to different processing strategies or attentional deployments between adults and children. These results suggest that the ability of memory selection is not fully developed in young children, resulting in their inefficient filtering of attended yet outdated information that is not required for memory retention.

Long-lasting negativity in the left motoric brain structures during word memory inhibition in the Think/No-Think paradigm.

In this study, we investigated the electrical brain responses in a high-density EEG array (64 electrodes) elicited specifically by the word memory cue in the Think/No-Think paradigm in 46 participants. In a first step, we corroborated previous findings demonstrating sustained and reduced brain electrical frontal and parietal late potentials elicited by memory cues following the No-Think (NT) instructions as compared to the Think (T) instructions. The topographical analysis revealed that such reduction was significant 1000 ms after memory cue onset and that it was long-lasting for 1000 ms. In a second step, we estimated the underlying brain generators with a distributed method (swLORETA) which does not preconceive any localization in the gray matter. This method revealed that the cognitive process related to the inhibition of memory retrieval involved classical motoric cerebral structures with the left primary motor cortex (M1, BA4), thalamus, and premotor cortex (BA6). Also, the right frontal-polar cortex was involved in the T condition which we interpreted as an indication of its role in the maintaining of a cognitive set during remembering, by the selection of one cognitive mode of processing, Think, over the other, No-Think, across extended periods of time, as it might be necessary for the successful execution of the Think/No-Think task.

Dexmedetomidine attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora.

Dexmedetomidine (Dex) has been used in surgery to improve patients' postoperative cognitive function. However, the role of Dex in stress-induced anxiety-like behaviors and cognitive impairment is still unclear. In this study, we tested the role of Dex in anxiety-like behavior and cognitive impairment induced by acute restrictive stress and analyzed the alterations of the intestinal flora to explore the possible mechanism. Behavioral and cognitive tests, including open field test, elevated plus-maze test, novel object recognition test, and Barnes maze test, were performed. Intestinal gut Microbe 16S rRNA sequencing was analyzed. We found that intraperitoneal injection of Dex significantly improved acute restrictive stress-induced anxiety-like behavior, recognition, and memory impairment. After habituation in the environment, mice (male, 8 weeks, 18-23 g) were randomly divided into a control group (control, N = 10), dexmedetomidine group (Dex, N = 10), AS with normal saline group (AS + NS, N = 10) and AS with dexmedetomidine group (AS + Dex, N = 10). By the analysis of intestinal flora, we found that acute stress caused intestinal flora disorder in mice. Dex intervention changed the composition of the intestinal flora of acute stress mice, stabilized the ecology of the intestinal flora, and significantly increased the levels of Blautia (A genus of anaerobic bacteria) and Coprobacillus. These findings suggest that Dex attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora.

Drift of neural ensembles driven by slow fluctuations of intrinsic excitability.

Representational drift refers to the dynamic nature of neural representations in the brain despite the behavior being seemingly stable. Although drift has been observed in many different brain regions, the mechanisms underlying it are not known. Since intrinsic neural excitability is suggested to play a key role in regulating memory allocation, fluctuations of excitability could bias the reactivation of previously stored memory ensembles and therefore act as a motor for drift. Here, we propose a rate-based plastic recurrent neural network with slow fluctuations of intrinsic excitability. We first show that subsequent reactivations of a neural ensemble can lead to drift of this ensemble. The model predicts that drift is induced by co-activation of previously active neurons along with neurons with high excitability which leads to remodeling of the recurrent weights. Consistent with previous experimental works, the drifting ensemble is informative about its temporal history. Crucially, we show that the gradual nature of the drift is necessary for decoding temporal information from the activity of the ensemble. Finally, we show that the memory is preserved and can be decoded by an output neuron having plastic synapses with the main region.

Early adversity causes sex-specific deficits in perforant pathway connectivity and contextual memory in adolescent mice.

BACKGROUND: Early life adversity impairs hippocampal development and function across diverse species. While initial evidence indicated potential variations between males and females, further research is required to validate these observations and better understand the underlying mechanisms contributing to these sex differences. Furthermore, most of the preclinical work in rodents was performed in adult males, with only few studies examining sex differences during adolescence when such differences appear more pronounced. To address these concerns, we investigated the impact of limited bedding (LB), a mouse model of early adversity, on hippocampal development in prepubescent and adolescent male and female mice. METHODS: RNA sequencing, confocal microscopy, and electron microscopy were used to evaluate the impact of LB and sex on hippocampal development in prepubescent postnatal day 17 (P17) mice. Additional studies were conducted on adolescent mice aged P29-36, which included contextual fear conditioning, retrograde tracing, and ex vivo diffusion magnetic resonance imaging (dMRI). RESULTS: More severe deficits in axonal innervation and myelination were found in the perforant pathway of prepubescent and adolescent LB males compared to LB female littermates. These sex differences were due to a failure of reelin-positive neurons located in the lateral entorhinal cortex (LEC) to innervate the dorsal hippocampus via the perforant pathway in males, but not LB females, and were strongly correlated with deficits in contextual fear conditioning. CONCLUSIONS: LB impairs the capacity of reelin-positive cells located in the LEC to project and innervate the dorsal hippocampus in LB males but not female LB littermates. Given the critical role that these projections play in supporting normal hippocampal function, a failure to establish proper connectivity between the LEC and the dorsal hippocampus provides a compelling and novel mechanism to explain the more severe deficits in myelination and contextual freezing found in adolescent LB males.

Childhood adversity, such as severe deprivation and neglect, leads to structural changes in human brain development that are associated with learning deficits and behavioral difficulties. Some of the most consistent findings in individuals exposed to childhood adversity are reduced hippocampal volume and abnormal hippocampal function. This is important because the hippocampus is necessary for learning and memory, and it plays a crucial role in depression and anxiety. Although initial studies suggested more pronounced hippocampal deficits in men, additional research is needed to confirm these findings and to elucidate the mechanisms responsible for these sex differences. We found that male and female mice exposed to early impoverishment and deprivation exhibit similar structural changes to those observed in deprived children. Interestingly, adolescent male mice, but not females, display severe deficits in their ability to freeze when placed back in a box where they were previously shocked. The ability to associate "shock/danger" with a "box/place" is referred to as contextual fear conditioning and requires normal connections between the entorhinal cortex and the hippocampus. We found that these connections did not form properly in male mice exposed to impoverished conditions, but they were only minimally affected in females. These findings appear to explain why exposure to impoverished conditions impairs contextual fear conditioning in male mice but not in female mice. Additional work is needed to determine whether similar sex-specific changes in these connections are also observed in adolescents exposed to neglect and deprivation.

Mitigating cognitive deficits with teriflunomide: unraveling PI3K-modulated behavioral outcomes in mice.

BACKGROUND: Alzheimer's disease is a leading neurological disorder that gradually impairs memory and cognitive abilities, ultimately leading to the inability to perform even basic daily tasks. Teriflunomide is known to preserve neuronal activity and protect mitochondria in the brain slices exposed to oxidative stress. The current research was undertaken to investigate the teriflunomide's cognitive rescuing abilities against scopolamine-induced comorbid cognitive impairment and its influence on phosphatidylinositol-3-kinase (PI3K) inhibition-mediated behavior alteration in mice. METHODS: Swiss albino mice were divided into 7 groups; vehicle control, scopolamine, donepezil + scopolamine, teriflunomide (10 mg/kg) + scopolamine; teriflunomide (20 mg/kg) + scopolamine, LY294002 and LY294002 + teriflunomide (20 mg/kg). Mice underwent a nine-day protocol, receiving scopolamine injections (2 mg/kg) for the final three days to induce cognitive impairment. Donepezil, teriflunomide, and LY294002 treatments were given continuously for 9 days. MWM, Y-maze, OFT and rota-rod tests were conducted on days 7 and 9. On the last day, blood samples were collected for serum TNF-α analysis, after which the mice were sacrificed, and brain samples were harvested for oxidative stress analysis. RESULTS: Scopolamine administration for three consecutive days increased the time required to reach the platform in the MWM test, whereas, reduced the percentage of spontaneous alternations in the Y-maze, number of square crossing in OFT and retention time in the rota-rod test. In biochemical analysis, scopolamine downregulated the brain GSH level, whereas it upregulated the brain TBARS and serum TNF-α levels. Teriflunomide treatment effectively mitigated all the behavioral and biochemical alterations induced by scopolamine. Furthermore, LY294002 administration reduced the memory function and GSH level, whereas, uplifted the serum TNF-α levels. Teriflunomide abrogated the memory-impairing, GSH-lowering, and TNF-α-increasing effects of LY294002. CONCLUSION: Our results delineate that the improvement in memory, locomotion, and motor coordination might be attributed to the oxidative and inflammatory stress inhibitory potential of teriflunomide. Moreover, PI3K inhibition-induced memory impairment might be attributed to reduced GSH levels and increased TNF-α levels.

Beneficial effects of metformin treatment on memory impairment.

Memory issues are a prevalent symptom in different neurodegenerative diseases and can also manifest in certain psychiatric conditions. Despite limited medications approved for treating memory problems, research suggests a lack of sufficient options in the market. Studies indicate that a significant percentage of elderly individuals experience various forms of memory disorders. Metformin, commonly prescribed for type 2 diabetes, has shown neuroprotective properties through diverse mechanisms. This study explores the potential of metformin in addressing memory impairments. The current research gathered its data by conducting an extensive search across electronic databases including PubMed, Web of Science, Scopus, and Google Scholar. Previous research suggests that metformin enhances brain cell survival and memory function in both animal and clinical models by reducing oxidative stress, inflammation, and cell death while increasing beneficial neurotrophic factors. The findings of the research revealed that metformin is an effective medication for enhancing various types of memory problems in numerous studies. Given the rising incidence of memory disorders, it is plausible to utilize metformin, which is an affordable and accessible drug. It is often recommended as a treatment to boost memory.

Effective modulation from the ventral medial to the dorsal medial portion of the prefrontal cortex in memory confidence-based behavioral control.

Metacognition includes the ability to refer to one's own cognitive states, such as confidence, and adaptively control behavior based on this information. This ability is thought to allow us to predictably control our behavior without external feedback, for example, even before we take action. Many studies have suggested that metacognition requires a brain-wide network of multiple brain regions. However, the modulation of effective connectivity within this network during metacognitive tasks remains unclear. This study focused on medial prefrontal regions, which have recently been suggested to be particularly involved in metacognition. We examined whether modulation of effective connectivity specific to metacognitive behavioral control is observed using model-based network analysis and dynamic causal modeling (DCM). The results showed that negative modulation from the ventral medial prefrontal cortex to the dorsal medial prefrontal cortex was observed in situations that required metacognitive behavioral control but not in situations that did not require such metacognitive control. Furthermore, this modulation was particularly pronounced in the group of participants who could better use metacognition for behavioral control. These results imply hierarchical properties of metacognition-related brain networks.

A sparse quantized hopfield network for online-continual memory.

An important difference between brains and deep neural networks is the way they learn. Nervous systems learn online where a stream of noisy data points are presented in a non-independent, identically distributed way. Further, synaptic plasticity in the brain depends only on information local to synapses. Deep networks, on the other hand, typically use non-local learning algorithms and are trained in an offline, non-noisy, independent, identically distributed setting. Understanding how neural networks learn under the same constraints as the brain is an open problem for neuroscience and neuromorphic computing. A standard approach to this problem has yet to be established. In this paper, we propose that discrete graphical models that learn via an online maximum a posteriori learning algorithm could provide such an approach. We implement this kind of model in a neural network called the Sparse Quantized Hopfield Network. We show our model outperforms state-of-the-art neural networks on associative memory tasks, outperforms these networks in online, continual settings, learns efficiently with noisy inputs, and is better than baselines on an episodic memory task.

Human intraparietal sulcal morphology relates to individual differences in language and memory performance.

The sulco-gyral pattern is a qualitative feature of the cortical anatomy that is determined in utero, stable throughout lifespan and linked to brain function. The intraparietal sulcus (IPS) is a nodal associative brain area, but the relation between its morphology and cognition is largely unknown. By labelling the left and right IPS of 390 healthy participants into two patterns, according to the presence or absence of a sulcus interruption, here we demonstrate a strong association between the morphology of the right IPS and performance on memory and language tasks. We interpret the results as a morphological advantage of a sulcus interruption, probably due to the underlying white matter organization. The right-hemisphere specificity of this effect emphasizes the neurodevelopmental and plastic role of sulcus morphology in cognition prior to lateralisation processes. The results highlight a promising area of investigation on the relationship between cognitive performance, sulco-gyral pattern and white matter bundles.

Memory, mood and associated neuroanatomy in individuals with steroid sulphatase deficiency (X-linked ichthyosis).

Steroid sulphatase (STS) cleaves sulphate groups from steroid hormones, and steroid (sulphate) levels correlate with mood and age-related cognitive decline. In animals, STS inhibition or deletion of the associated gene, enhances memory/neuroprotection and alters hippocampal neurochemistry. Little is known about the consequences of constitutive STS deficiency on memory-related processes in humans. We investigated self-reported memory performance (Multifactorial Memory Questionnaire), word-picture recall and recent mood (Kessler Psychological Distress Scale, K10) in adult males with STS deficiency diagnosed with the dermatological condition X-linked ichthyosis (XLI; n = 41) and in adult female carriers of XLI-associated genetic variants (n = 79); we compared results to those obtained from matched control subjects [diagnosed with ichthyosis vulgaris (IV, n = 98) or recruited from the general population (n = 250)]. Using the UK Biobank, we compared mood/memory-related neuroanatomy in carriers of genetic deletions encompassing STS (n = 28) and non-carriers (n = 34,522). We found poorer word-picture recall and lower perceived memory abilities in males with XLI and female carriers compared with control groups. XLI-associated variant carriers and individuals with IV reported more adverse mood symptoms, reduced memory contentment and greater use of memory aids, compared with general population controls. Mood and memory findings appeared largely independent. Neuroanatomical analysis only indicated a nominally-significantly larger molecular layer in the right hippocampal body of deletion carriers relative to non-carriers. In humans, constitutive STS deficiency appears associated with mood-independent impairments in memory but not with large effects on underlying brain structure; the mediating psychobiological mechanisms might be explored further in individuals with XLI and in new mammalian models lacking STS developmentally.