Subjective cognitive decline (SCD) is defined as self-experienced cognitive decline without objective impairment on standardised tests. Research suggests SCD may show subtle impairment on detailed neuropsychological assessment and might therefore indicate the earliest stage of neurodegeneration. This review (PROSPERO: CRD42023382096) seeks to determine whether group differences in memory task performance between people with and without SCD exist. The review included studies since 2014 comparing episodic memory performance between people with and without SCD; where people with SCD were recruited exclusively from community or medical settings. Studies providing data for people with mild cognitive impairment (MCI) were included in a separate meta-analysis comparing SCD and MCI. A systematic search was conducted (PsycINFO, Web of Science, MEDLINE, CINAHL, PubMed on 11th August 2023). Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. 1,815 records were identified, of which 45 met inclusion criteria and were included in a random-effects meta-analysis (SCD N = 5,948, Non-SCD N = 8,468). Twenty-one studies additionally provided data for an MCI group (SCD N = 1,034, MCI N = 2,119). Results indicated people with SCD performed significantly worse than people without SCD (Hedges' g = -0.19, 95% CI = -0.26, -0.11) and significantly better than MCI participants (Hedges' g = 1.20, 95% CI = 0.94, 1.46). For both meta-analyses there was significant between-study heterogeneity. There was a significant risk of publication bias for the meta-analysis comparing SCD to Non-SCD. These results suggest detailed memory assessment may be sensitive to reduced objective memory performance in SCD. However, it is unclear whether the small effect size has clinical significance. Higher quality and larger studies are needed to rule out the influence of moderating factors on memory performance.

This systematic review aimed to identify preserved and impaired memory processes in Huntington's disease (HD), with consideration of disease stage and the specific memory subsystems assessed. A systematic search was conducted in PubMed, ScienceDirect, and Google Scholar up to March 11, 2025. Eligible studies had to be peer-reviewed, had to involve participants aged 18 or older, had to include patients with genetically or clinically confirmed HD, and had to be published in English or French. Risk of bias was assessed using the ROBINS-I tool. A structured narrative synthesis was performed across seven memory subsystems and clinical stages (pre-manifest vs. manifest), and findings were summarized using tables and figures. A total of 136 studies were included. Verbal episodic memory impairments were consistently observed from early stages, particularly in free recall, while recognition was initially preserved. Visual episodic memory showed progressive deficits. Olfactory memory, though rarely examined, appeared to be impaired early. Autobiographical memory was underinvestigated but showed signs of disruption, seemingly independent of executive dysfunction. Semantic memory was generally preserved but showed reduced access without cues. Early-stage impairments were also reported in working memory. Priming was preserved, while complex procedural learning tasks showed variable deficits. Many studies presented methodological limitations, including confounding and lack of blinding. Memory profiles in HD appear heterogeneous and subsystem-specific. Autobiographical memory may constitute a distinct cognitive marker. Improved characterization of memory deficits is crucial to guide the development of targeted cognitive interventions.

Evidence exists that cocaine impacts cognition and behaviour. Yet, uncertainty remains as to what extent cognitive inhibition efficiency decreases in cocaine users. We carried out a systematic review and meta-analysis following the PRISMA 2020 checklist. Our search yielded 1725 articles from Scopus, PubMed and WOS, from which twenty-four studies were finally identified as meeting the inclusion criteria for the systematic review and twenty (providing twenty-three effect sizes) for the meta-analysis. A multi-level random-effects meta-analysis was conducted, and moderation analysis was implemented to examine the potential moderating effects of sex, age, years of regular cocaine use, days of cocaine abstinence, and sample type (clinical vs. community) in the estimated effects. Results showed worse inhibition in cocaine users compared to controls (g = 0.65; 95% CI [0.28, 1.03], p < .001), but none of the moderators significantly impacted this effect. Findings highlight the link between impaired cognitive inhibition and cocaine use disorder and suggest that inhibitory control training approaches would be promising. Future clinical studies are needed to elucidate on the efficacy of neuropsychological approaches for improving inhibitory control and augment the effectiveness of first-line interventions for cocaine use disorder.

Episodic memory impairment can persist in persons with HIV (PWH) despite treatment. Depression is among the most prevalent comorbidities in HIV. Changes to brain regions involved in episodic memory like the hippocampus and the prefrontal cortex have been well documented in depression. If episodic memory changes occur in PWH, it is important to understand the potential impact of concurrent depressive symptoms (DS). Thus, our objective was to conduct a systematic review and meta-analysis on the role of DS in episodic memory in PWH. We included cross-sectional and longitudinal studies that provided episodic memory test scores and a formal assessment of DS expecting that episodic memory in PWH (A) be lower with comorbid DS; (B) negatively correlated with DS severity and incidence of clinical depression; and (C) declines over time with comorbid depression. Following PRIMSA guidelines, 3505 papers were identified, of which 44 studies were ultimately included. Meta-analysis demonstrated that immediate but not delayed recall were lower in PWH with DS than without DS, with small average effect sizes. An inverse relationship between DS severity and episodic memory performance emerged in about a quarter of the studies, with a higher likelihood in studies measuring incidence of clinically elevated DS. If observed, longitudinal memory decline was limited to moderately-severely depressed PWH. Our results suggest that prevention and treatment of clinical levels of depressive symptomatology in PWH remains a paramount target in HIV care with important implications for memory and likely other cognitive functions long-term.

The purpose of this systematic review was to synthesize the current evidence on motor learning in mild cognitive impairment (MCI). A search of five databases returned a total of 6058 references, 10 of which met criteria for inclusion in this review. The existing evidence was notably variable with an overall moderate risk of bias. Eight articles compared behavioral motor learning outcomes in MCI and age matched, non-cognitively impaired (NCI) samples. In 37.5% of these studies, the degree of motor skill acquisition in the MCI group was statistically significantly less than in the NCI group. Skill retention was only compared between MCI and NCI samples in one article, which reported a relative reduction in MCI group performance following a 24-h, no-practice delay. Importantly, none of the included articles examined motor skill transfer. We discuss possible sources of heterogeneity among collective findings including variability in motor tasks, outcome measurement, and research design. Further research is needed to support a comprehensive understanding of motor learning in the early stages of age-related cognitive decline. Future investigations should emphasize functional motor tasks and clinically relevant learning outcomes, including retention and transfer of motor skills, while controlling for potentially confounding factors such as motivation and sleep performance. This systematic review was registered with PROSPERO international prospective register of systematic reviews (registration ID CRD42023417329).

To effectively diagnose and treat subjective cognitive symptoms in post-acute sequalae of COVID-19 (PASC), it is important to understand objective cognitive impairment across the range of acute COVID-19 severity. Despite the importance of this area of research, to our knowledge, there are no current meta-analyses of objective cognitive functioning following non-severe initial SARS-CoV-2 infection. The aim of this meta-analysis is to describe objective cognitive impairment in individuals with non-severe (mild or moderate) SARS-CoV-2 cases in the post-acute stage of infection. This meta-analysis was pre-registered with Prospero (CRD42021293124) and utilized the PRISMA checklist for reporting guidelines, with screening conducted by at least two independent reviewers for all aspects of the screening and data extraction process. Fifty-nine articles (total participants = 22,060) with three types of study designs met our full criteria. Individuals with non-severe (mild/moderate) initial SARS-CoV-2 infection demonstrated worse objective cognitive performance compared to healthy comparison participants. However, those with mild (nonhospitalized) initial SARS-CoV-2 infections had better objective cognitive performance than those with moderate (hospitalized but not requiring ICU care) or severe (hospitalized with ICU care) initial SARS-CoV-2 infections. For studies that used normative data comparisons instead of healthy comparison participants, there was a small and nearly significant effect when compared to normative data. There were high levels of heterogeneity (88.6 to 97.3%), likely reflecting small sample sizes and variations in primary study methodology. Individuals who have recovered from non-severe cases of SARS-CoV-2 infections may be at risk for cognitive decline or impairment and may benefit from cognitive health interventions.

The first 6 years of lifeare when 90% of brain development occurs, setting the foundation for lifelong neurodevelopment. The field of infant and early childhood neurodevelopment has made marginal advancements since introduced in 1988. There remains a gap in knowledge around early neurodevelopmental domains and trajectories given that there are few established assessment procedures for infants and young children and controversies around reserving assessments until school age. Throughout this systematic review, we (1) identified neurodevelopmental assessment measures employed in the literature by domain and age of assessment, (2) compiled a repository of 608 domain-specific neurodevelopmental assessment measures, and (3) established a preliminary conceptual framework for cross-domain neurodevelopmental assessments across infancy and early childhood. This review adhered to PRISMA guidelines and spanned three databases (PsycINFO, MEDLINE, PubMed). Articles were reviewed for (1) infancy and early childhood (0-6 years), (2) neurodevelopmental measures, and (3) English language. This systematic review spanned 795 articles from 1978 to 2020 with international representation. Advancements in assessment methods (e.g. measures, domains, frameworks) are essential for the evaluation of early neurodevelopmental profiles to inform early interventions, thus harnessing the neuroplasticity and dynamic development notable during early childhood. We hope this work catalyzes future research and clinical guidelines around early assessments methods.

Thalamus function and structure are known predictors of individual differences in the risk of age-related neurocognitive disorders (NCD), such as dementia. However, to date, little is known about their role in the perioperative setting. Here, we provide a narrative review of brain-imaging studies of preoperative and postoperative thalamus scanning parameters associated with risks of developing perioperative NCD, such as postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) during the postoperative phase. These findings are discussed in light of the concept of reserve capacity.

In this study, we ran a meta-analysis of neuroimaging studies to pinpoint the neural regions that are commonly activated across space, time, and numerosity, and we tested the existence of gradient transitions among these magnitude representations in the brain. Following PRISMA guidelines, we included in the meta-analysis 112 experiments (for space domain), 114 experiments (time domain), and 115 experiments (numerosity domain), and we used the activation likelihood estimation method. We found a system of brain regions that was commonly recruited in all the three magnitudes, which included bilateral insula, the supplementary motor area (SMA), the right inferior frontal gyrus, and bilateral intraparietal sulci. Gradiental transitions between different magnitudes were found along all these regions but insulae, with space and numbers leading to gradients mainly over parietal regions (and SMA) whereas time and numbers mainly over frontal regions. These findings provide evidence for the GradiATOM theory (Gradient Theory of Magnitude), suggesting that spatial proximity given by overlapping activations and gradients is a key aspect for efficient interactions and integrations among magnitudes.