Search Results (38)

Background/Objectives: Autobiographical memory (AM) is typically viewed in terms of comprising episodic (EAM) and semantic (SAM) components. Despite the emergence of numerous meta-analyses, the literature on these constructs remains fragmented. We aimed to summarize neural activations and to discuss the relations between constructs based on theory and experimentation, while evaluating the consistency between literature sources and discussing the critical issues and challenges of current research. Methods: We conducted a scoping meta-review on AM, EAM, and SAM based on meta-analytic studies in five scientific databases (PubMed, Web of Science, Scopus, PsychInfo, and PsychArticles). No temporal or language limits were applied. Results: We included twelve meta-analyses on AM, EAM and SAM in healthy populations. The meta-analyses of AM and EAM actually investigated the same construct, leading to misinterpretation. The two available meta-analyses on SAM used two different operationalizations of the construct. Neural data about EAM were analyzed via mean rank classification, finding the most relevant areas in the posterior cingulate cortex, hippocampus, precuneus, temporo-parietal junction, angular gyrus, and medial prefrontal cortex. SAM was linked to the posterior and anterior cingulate cortexes, middle and inferior frontal gyri, thalamus, middle and superior temporal gyri, inferior frontal and fusiform gyri, and parahippocampal cortex. Conclusions: Variability in reported activation patterns persists, reflecting differences in methodology and assumptions. We propose the homogenization the notations of EAM and AM based on experimental practice. In this notation, AM does not have a separate experimental task nor activation pattern and may not indicate a separate construct but an array of its components. Full article

Background/Objectives: Sexual minority older adults (SMOAs) report greater subjective cognitive decline (SCD) than heterosexual older adults (HOAs). This study aimed to compare the impact of multiple psycho-social risk factors on objective and subjective cognitive decline in HOAs and SMOAs. Methods: Two samples of self-identified HOAs and SMOAs were selected from the English Longitudinal Study of Ageing. Reliable change indices for episodic and semantic memory were created to assess cognitive decline. SCD was self-reported for memory and general cognition. Depressive symptoms, loneliness, marital status and socio-economic status were investigated as risk factors. Results: No between-group differences were found in cognitive decline. Higher depression was associated with greater SCD risk and worse semantic memory decline. The latter effect was stronger in SMOAs. The findings were largely replicated in the sensitivity analysis. Conclusions: Poor mental health may represent the strongest driver of cognitive decline in SMOAs and to a greater extent than in HOAs. Full article

Background: Aortic valve stenosis (AVS) is a common valvular heart disease affecting millions of people worldwide. It leads to significant neurocognitive and neuropsychological impairments, impacting patients’ quality of life. Objective: The objective of this article is to identify and discuss the potential neurocognitive effects on patients with aortic stenosis before and after undergoing surgical aortic valve replacement (SAVR). Method: Our study involved the assessment of 64 patients undergoing aortic valve replacement (SAVR) using a neurocognitive evaluation comprising a battery of 11 different cognitive tests. These tests were designed to analyze the patients’ overall cognitive functioning, executive abilities, short- and long-term memory, and attentional performance. The tests were administered to patients before the aortic valve surgery (T0) and after the surgery (T1). From a statistical perspective, numerical variables are presented as means (±standard deviation) and medians (IQR), while categorical variables are presented as counts and percentages. Normality was assessed using the Shapiro–Wilk test. T0 and T1 scores were compared with the Wilcoxon signed rank test, with p < 0.05 considered significant. Analyses were performed using SAS version 9.4. Results: Conducted as part of a fully financed Italian Ministry of Health project (RF-2016-02361069), the study found that most patients showed normal cognitive functioning at baseline. Cognitive assessments showed that executive functions, attention, language, and semantic knowledge were within the normal range for the majority of participants. After SAVR, cognitive outcomes remained stable or improved, particularly in executive functions and language. Notably, verbal episodic memory demonstrated significant improvement, with the percentage of patients scoring within the normal range on the BSRT increasing from 73.4% at T0 to 92.2% at T1 (p < 0.0001). However, visuospatial and visuoconstructive abilities showed stability or slight decline, while attentional skills remained relatively stable. The Clock Drawing Test indicated the maintenance of cognitive functions. Conclusions: The findings of our study indicate a global stability in cognitive status among patients after undergoing SAVR, with significant improvement noted in verbal episodic memory. While other cognitive domains did not demonstrate statistically significant changes, these insights are valuable for understanding the cognitive effects of SAVR and can guide future research and clinical practice in selecting the most effective surgical and rehabilitative options for patients. Monitoring cognitive outcomes in patients undergoing aortic valve replacement surgery remains crucial. Full article

Unmanned Aerial Vehicles (UAVs) have garnered widespread attention in reconnaissance and search operations due to their low cost and high flexibility. However, when multiple UAVs (multi-UAV) collaborate on these tasks, a limited communication range can restrict their efficiency. This paper investigates the problem of multi-UAV collaborative reconnaissance and search for static targets with a limited communication range (MCRS-LCR). To address communication limitations, we designed a communication and information fusion model based on belief maps and modeled MCRS-LCR as a multi-objective optimization problem. We further reformulated this problem as a decentralized partially observable Markov decision process (Dec-POMDP). We introduced episodic memory into the reinforcement learning framework, proposing the CNN-Semantic Episodic Memory Utilization (CNN-SEMU) algorithm. Specifically, CNN-SEMU uses an encoder–decoder structure with a CNN to learn state embedding patterns influenced by the highest returns. It extracts semantic features from the high-dimensional map state space to construct a smoother memory embedding space, ultimately enhancing reinforcement learning performance by recalling the highest returns of historical states. Extensive simulation experiments demonstrate that in reconnaissance and search tasks of various scales, CNN-SEMU surpasses state-of-the-art multi-agent reinforcement learning methods in episodic rewards, search efficiency, and collision frequency. Full article

Accelerated brain aging is a possible mechanism of pathology in schizophrenia. Advances in MRI-based brain development algorithms allow for the calculation of predicted brain age (PBA) for individuals. Here, we assessed PBA in 70 first-episode schizophrenia-spectrum individuals (FESz) and 76 matched healthy neurotypical comparison individuals (HC) to determine if FESz showed advanced aging proximal to psychosis onset and whether PBA was associated with neurocognitive, social functioning, or symptom severity measures. PBA was calculated with BrainAgeR (v2.1) from T1-weighted MR scans. There were no differences in the PBAs between groups. After controlling for actual age, a “younger” PBA was associated with higher vocabulary scores among all individuals, while an “older” PBA was associated with more severe negative symptom “Inexpressivity” component scores among FESz. Female participants in both groups had an elevated PBA relative to male participants. These results suggest that a relatively younger brain age is associated with a better semantic memory performance. There is no evidence for accelerated aging in FESz with a late adolescent/early adult onset. Despite a normative PBA, FESz with a greater residual PBA showed impairments in a cluster of negative symptoms, which may indicate some underlying age-related pathology proximal to psychosis onset. Although a period of accelerated aging cannot be ruled out with disease course, it does not occur at the time of the first episode. Full article

Normal aging is commonly accompanied by a decline in cognitive abilities, including memory, yet some individuals maintain these abilities as they get older. We hypothesize that semantic clustering, as an effective strategy for improving performance on episodic recall tasks, may contribute to the maintenance of youthful memory in older adults. We investigated the dynamics of spontaneous production and utilization of the semantic clustering strategy in two independent samples of older adults who completed a list learning paradigm (N₁ = 40 and N₂ = 29, respectively). Specifically, we predicted and observed that older adults who spontaneously used a semantic clustering strategy throughout the encoding process learned more words by the culmination of the encoding trials (Sample 1, R²= 0.53, p < 0.001; Sample 2, R²= 0.51, p < 0.001), and that those who utilized this strategy during retrieval recalled more words, when compared to older adults who did not produce or utilize a semantic clustering strategy during both a short (Sample 1, R² = 0.81, p < 0.001; Sample 2, R² = 0.70, p < 0.001) and long delay retrieval (Sample 1, R² = 0.83, p < 0.001; Sample 2, R² = 0.77, p < 0.001). We further predicted and observed that older adults who maintained a youthful level of delayed free recall (i.e., “Superagers”) produced (Sample 1, F(1, 38) = 17.81, p < 0.0001; Sample 2, F(1, 27) = 14.45, p < 0.0001) and utilized (Sample 1, F(1, 39) = 25.84, p < 0.0001; Sample 2, F(1, 27) = 12.97, p < 0.01) more semantic clustering than did older individuals with normal memory for their age. These results suggest one cognitive mechanism through which Superagers maintain youthful memory function and raise the possibility that older adults may be able to train themselves to use strategies to promote better memory. Full article

High blood pressure is associated with an elevated risk of dementia. However, much less is known about how high blood pressure is related to cognitive deficits in domains including episodic memory, semantic verbal fluency, fluid reasoning, and numerical ability. By analyzing data from 337 participants (57.39% female) with a history of clinical high blood pressure diagnosis with a mean age of 48.78 ± 17.06 years and 26,707 healthy controls (58.75% female) with a mean age of 45.30 ± 15.92 years using a predictive normative modeling approach and one-sample t-tests, the current study found that people with high blood pressure have impaired immediate (t(259) = −4.71, p < 0.01, Cohen’s d = −0.08, 95% C.I. [−0.11, −0.05]) and delayed word recall (t(259) = −7.21, p < 0.01, Cohen’s d = −0.11, 95% C.I. [−0.15, −0.08]) performance. Moreover, people with high blood pressure also exhibited impaired performance in the animal naming task (t(259) = −6.61, p < 0.0001, Cohen’s d = −0.11, 95% C.I. [−0.15, −0.08]), and number series (t(259) = −4.76, p < 0.01, Cohen’s d = −0.08, 95% C.I. [−0.11, −0.05]) and numeracy tasks (t(259) = −4.16, p < 0.01, Cohen’s d = −0.06, 95% C.I. [−0.09, −0.03]) after controlling for demographic characteristics. Clinicians and health professionals should consider including these tasks as part of the neuropsychological assessment for people with high blood pressure, to detect their cognitive deficits. Moreover, they should also come up with ways to improve cognitive performance in people with high blood pressure. Full article

This paper begins with a short case report of florid, spontaneous confabulation in a 61-year-old man with an alcohol-induced Wernicke-Korsakoff syndrome. His confabulation extended across episodic and personal semantic memory, as well as orientation in time and place, as measured on Dalla Barba’s Confabulation Battery. Five other brief case summaries will then be presented, followed by a summary of the clinical, neurological, and background neuropsychological findings in three earlier series of Korsakoff patients. These observations will be considered in light of Wijnia’s recent and my own, earlier reviews of the Korsakoff syndrome. Taken together, they indicate the need for a multi-faceted approach (clinical, neurological, neuropsychological, and neuroimaging) to the assessment and diagnosis of the disorder. Full article

Cognitive deficits are commonly seen in people with arthritis. However, previous studies focused primarily on small-sized clinical samples. There is a need for cohort-based studies, which are characterized by high generalizability. In addition, these studies mainly focused on attention, memory, and executive function. However, cognition is not a single concept, but includes other cognitive domains, such as verbal fluency and arithmetic abilities. Thus, we aim to explore how arthritis can affect cognitive abilities, including episodic memory, semantic verbal fluency, fluid reasoning, and numerical ability by using a large cohort from the United Kingdom. The main findings were that people with arthritis have significantly lower immediate word recall (t(2257) = −6.40, p < 0.001, Cohen’s d = −0.12, 95% C.I. = [−0.16, −0.08]), delayed word recall (t(2257) = −5.60, p < 0.001, Cohen’s d = −0.11, 95% C.I. = [−0.14, −0.07]), semantic verbal fluency (t(2257) = −3.03, p < 0.01, Cohen’s d = −0.06, 95% C.I. = [−0.10, −0.02]), fluid reasoning (t(2257) = −3.96, p < 0.001, Cohen’s d = −0.07, 95% C.I. = [−0.11, −0.04]), and numerical ability (t(2257) = −3.85, p < 0.001, Cohen’s d = −0.07, 95% C.I. = [−0.10, −0.03]) compared to what they would expect given their demographics. Interventions are needed to improve cognitive abilities in people with arthritis. Full article

Introduction: Mild cognitive impairment (MCI) is a syndrome defined as a decline in cognitive performance greater than expected for an individual according to age and education level, not interfering notably with daily life activities. Many studies have focused on the memory domain in the analysis of MCI and more severe cases of dementia. One specific memory system is represented by autobiographical memory (AM), which has been largely studied in Alzheimer’s disease and its effect on AM; however, the impairment of AM in moderate forms of decline, such as MCI, is still controversial. Objective: The main aim of this systematic review is to analyze the functioning of autobiographical memory in patients with MCI, considering both the semantic and the episodic components. Materials: The review process was conducted according to the PRISMA statement. The search was conducted until 20 February 2023 in the following bibliographical databases: PubMed, Web of Science, Scopus, and PsycInfo, and twenty-one articles were included. Results: The results highlight controversial findings concerning the semantic component of AM since only seven studies have found a worse semantic AM performance in patients with MCI compared to the HC group. The results of impaired episodic AM in individuals with MCI are more consistent than those concerning semantic AM. Conclusions: Starting from the evidence of this systematic review, further studies should detect and investigate the cognitive and emotional mechanisms that undermine AM performance, allowing the development of specific interventions targeting these mechanisms. Full article

Illusory conscious experience of the “presentation” of unstudied material, called phantom recollection, occurs at high levels in long-term episodic memory tests and underlies some forms of false memory. We report an experiment examining, for the first time, the presence of phantom recollection in a short-term working memory (WM) task in 8- to 10-year-old children and young adults. Participants studied lists of eight semantically related words and had to recognize them among unpresented distractors semantically related and unrelated to the studied words after a retention interval of a few seconds. Regardless of whether the retention interval was filled with a concurrent task that interfered with WM maintenance, the false recognition rate for related distractors was very high in both age groups, although it was higher in young adults (47%) than children (42%) and rivaled the rate of target acceptance. The conjoint recognition model of fuzzy-trace theory was used to examine memory representations underlying recognition responses. In young adults, phantom recollection underpinned half of the false memories. By contrast, in children, phantom recollection accounted for only 16% of them. These findings suggest that an increase in phantom recollection use may underlie the developmental increase in short-term false memory. Full article

With the advancement of artificial intelligence technologies in recent years, research on intelligent robots has progressed. Robots are required to understand human intentions and communicate more smoothly with humans. Since gestures can have a variety of meanings, gesture recognition is one of the essential issues in communication between robots and humans. In addition, robots need to learn new gestures as humans grow. Moreover, individual gestures vary. Because catastrophic forgetting occurs in training new data in traditional gesture recognition approaches, it is necessary to preserve the prepared data and combine it with further data to train the model from scratch. We propose a Multi-scopic Cognitive Memory System (MCMS) that mimics the lifelong learning process of humans and can continuously learn new gestures without forgetting previously learned gestures. The proposed system comprises a two-layer structure consisting of an episode memory layer and a semantic memory layer, with a topological map as its backbone. The system is designed with reference to conventional continuous learning systems in three ways: (i) using a dynamic architecture without setting the network size, (ii) adding regularization terms to constrain learning, and (iii) generating data from the network itself and performing relearning. The episode memory layer clusters the data and learns their spatiotemporal representation. The semantic memory layer generates a topological map based on task-related inputs and stores them as longer-term episode representations in the robot’s memory. In addition, to alleviate catastrophic forgetting, the memory replay function can reinforce memories autonomously. The proposed system could mitigate catastrophic forgetting and perform continuous learning by using both machine learning benchmark datasets and real-world data compared to conventional methods. Full article

Coronary heart disease (CHD) is one of the main cardiovascular diseases that can cause disability and death across the globe. Although previous research explored the links between CHD and cognitive deficits, only a subset of cognitive abilities was analyzed and a small clinical sample size was used. Thus, the aim of the current study is to assess how CHD can affect the cognitive domains of episodic memory, semantic verbal fluency, fluid reasoning, and numerical ability in a large cohort of participants from the United Kingdom. Results revealed that episodic memory, semantic verbal fluency, fluid reasoning, and numerical ability are negatively affected by CHD. Prevention and intervention should be developed to preserve cognitive abilities in people with CHD, but more studies should explore specific ways of doing so. Full article

The study aimed to assess the impact of clinical symptoms and cognitive impairment on disability in patients with paranoid schizophrenia (PS). Methods: 108 patients with schizophrenia were included (66 male and 42 female). Their average age was 38.86 ± 10.02 years and the disease duration was 12.80 ± 8.20 years, with mean disease onset of 24 years. Clinical symptoms were assessed with the PANSS, and cognitive performance was measured using a seven-item neurocognitive battery. The disability level of the subjects was assessed using the World Health Organization—Disability Assessment Schedule 2.0 (WHO-DAS 2.0). The relation between the variables studied was assessed using Spearman’s rank correlation coefficient (r_s) at a probability level of p < 0.05. Results: An increase in symptom severity resulted in worsening of the “participation in society” (r = 0.56, p < 0.01), “life activities—household” (r = 0.55, p < 0.01), and “getting along with people” (r = 0.59, p < 0.01) WHO-DAS 2.0 domains. Positive symptoms (13.89 ± 3.48) correlated strongly with “getting along with people” (r = 0.55, p < 0.01), “life activities—household” (r = 0.58, p < 0.01), and “participation in society” (r = 0.62, p < 0.01), and negative symptoms (14.25 ± 4.16) with “participation in society” (r = 0.53, p < 0.01) and “life activities—household” (r = 0.48, p < 0.01). Symptoms of disorganization (15.67 ± 4.16) had the highest impact on “life activities—household” (r = 0.81, p < 0.01), “getting along with people” (r = 0.56, p < 0.05), and “participation in society” (r = 0.65, p < 0.01). Episodic memory (r = −0.28, p < 0.01) was remotely related to comprehension and communication. The information processing speed (r_s = 0.38, p < 0.01), visual memory (r_s = −0.30, p < 0.01), and focused executive functions showed moderate correlations with all domains on the WHO-DAS 2.0 scale (r_s = 0.38, p < 0.01). Attention (r_s = −0.33, p < 0.01) was moderately related to community activities. Semantic (r_s = −0.29, p < 0.01) and literal (r_s = −0.27, p < 0.01) verbal fluency demonstrated weak correlations with “cognition—understanding”, “getting along with people”, and “participation in society”. Conclusion: Symptoms of disorganization and disturbed executive functions contribute most to disability in patients with schizophrenia through impairment of real-world functioning, especially in social interactions and communication. Severe clinical symptoms (negative and disorganization-related ones) as well as deficits in executive function, verbal memory, and verbal fluency cause the biggest problems in the functional domains of interaction with other people and participation in society. Full article

Early cognitive decline in patients with Alzheimer’s (AD) is associated with quantifiable structural and functional connectivity changes in the brain. AD dysregulation of Aβ and tau metabolism progressively disrupt normal synaptic function, leading to loss of synapses, decreased hippocampal synaptic density and early hippocampal atrophy. Advances in brain imaging techniques in living patients have enabled the transition from clinical signs and symptoms-based AD diagnosis to biomarkers-based diagnosis, with functional brain imaging techniques, quantitative EEG, and body fluids sampling. The hippocampus has a central role in semantic and episodic memory processing. This cognitive function is critically dependent on normal intrahippocampal connections and normal hippocampal functional connectivity with many cortical regions, including the perirhinal and the entorhinal cortex, parahippocampal cortex, association regions in the temporal and parietal lobes, and prefrontal cortex. Therefore, decreased hippocampal synaptic density is reflected in the altered functional connectivity of intrinsic brain networks (aka large-scale networks), including the parietal memory, default mode, and salience networks. This narrative review discusses recent critical issues related to detecting AD-associated early cognitive decline with brain synaptic structural and functional markers in high-risk or neuropsychologically diagnosed patients with subjective cognitive impairment or mild cognitive impairment. Full article