RESUMO
Deficits in memory performance have been linked to a wide range of neurological and neuropsychiatric conditions. While many studies have assessed the memory impacts of individual conditions, this study considers a broader perspective by evaluating how memory recall is differentially associated with nine common neuropsychiatric conditions using data drawn from 55 international studies, aggregating 15,883 unique participants aged 15-90. The effects of dementia, mild cognitive impairment, Parkinson's disease, traumatic brain injury, stroke, depression, attention-deficit/hyperactivity disorder (ADHD), schizophrenia, and bipolar disorder on immediate, short-, and long-delay verbal learning and memory (VLM) scores were estimated relative to matched healthy individuals. Random forest models identified age, years of education, and site as important VLM covariates. A Bayesian harmonization approach was used to isolate and remove site effects. Regression estimated the adjusted association of each clinical group with VLM scores. Memory deficits were strongly associated with dementia and schizophrenia (p < 0.001), while neither depression nor ADHD showed consistent associations with VLM scores (p > 0.05). Differences associated with clinical conditions were larger for longer delayed recall duration items. By comparing VLM across clinical conditions, this study provides a foundation for enhanced diagnostic precision and offers new insights into disease management of comorbid disorders.
RESUMO
Difficulties in executive functioning (EF) can result in impulsivity, forgetfulness, and inattention. Children living in remote/regional communities are particularly at risk of impairment in these cognitive skills due to reduced educational engagement and poorer access to interventions. This vulnerability has been exacerbated by the COVID-19 pandemic and strategies are needed to mitigate long-term negative impacts on EF. Here we propose a pilot trial investigating the benefits, feasibility, and acceptability of a school-based EF intervention for primary school students (6-8 years) living in regional, developmentally vulnerable, and socio-economically disadvantaged communities. Students were randomised to a digital intervention or teaching as usual, for 7 weeks. Children completed measures of EF and parents/educators completed ratings of everyday EF and social/emotional wellbeing at pre-intervention, post-intervention, and 3-month follow-up. Change in EFs (primary outcome), everyday EF, and social/emotional wellbeing (secondary outcomes) from pre- to post-intervention and pre-intervention to 3-month follow-up were examined. Feasibility and acceptability of the intervention was assessed through educator feedback and intervention adherence.Protocol Registration: The stage 1 protocol for this Registered Report was accepted in principle on 20 April 2023. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/WT3S2 . The approved Stage 1 protocol is available here: https://osf.io/kzfwn .
Assuntos
COVID-19 , Cognição , Humanos , Criança , COVID-19/psicologia , COVID-19/epidemiologia , Projetos Piloto , Masculino , Feminino , Função Executiva , Pandemias , SARS-CoV-2 , Instituições Acadêmicas , Estudantes/psicologiaRESUMO
'Embodied cognition' suggests that our bodily experiences broadly shape our cognitive capabilities. We study how embodied experience affects the abstract physical problem-solving styles people use in a virtual task where embodiment does not affect action capabilities. We compare how groups with different embodied experience - 25 children and 35 adults with congenital limb differences versus 45 children and 40 adults born with two hands - perform this task, and find that while there is no difference in overall competence, the groups use different cognitive styles to find solutions. People born with limb differences think more before acting but take fewer attempts to reach solutions. Conversely, development affects the particular actions children use, as well as their persistence with their current strategy. Our findings suggest that while development alters action choices and persistence, differences in embodied experience drive changes in the acquisition of cognitive styles for balancing acting with thinking.
RESUMO
It is clear that people can learn a new sensory skill-a new way of mapping sensory inputs onto world states. It remains unclear how flexibly a new sensory skill can become embedded in multisensory perception and decision-making. To address this, we trained typically sighted participants (N = 12) to use a new echo-like auditory cue to distance in a virtual world, together with a noisy visual cue. Using model-based analyses, we tested for key markers of efficient multisensory perception and decision-making with the new skill. We found that 12 of 14 participants learned to judge distance using the novel auditory cue. Their use of this new sensory skill showed three key features: (a) It enhanced the speed of timed decisions; (b) it largely resisted interference from a simultaneous digit span task; and (c) it integrated with vision in a Bayes-like manner to improve precision. We also show some limits following this relatively short training: Precision benefits were lower than the Bayes-optimal prediction, and there was no forced fusion of signals. We conclude that people already embed new sensory skills in flexible multisensory perception and decision-making after a short training period. A key application of these insights is to the development of sensory augmentation systems that can enhance human perceptual abilities in novel ways. The limitations we reveal (sub-optimality, lack of fusion) provide a foundation for further investigations of the limits of these abilities and their brain basis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Assuntos
Aprendizagem , Percepção Visual , Humanos , Teorema de Bayes , Percepção Auditiva , Estimulação LuminosaRESUMO
INTRODUCTION: Regular aerobic exercise is associated with improved cognitive function, implicating it as a strategy to reduce dementia risk. This is reinforced by the association between greater cardiorespiratory fitness and larger brain volume, superior cognitive performance and lower dementia risk. However, the optimal aerobic exercise dose, namely the intensity and mode of delivery, to improve brain health and lower dementia risk has received less attention. We aim to determine the effect of different doses of aerobic exercise training on markers of brain health in sedentary middle-aged adults, hypothesising that high-intensity interval training (HIIT) will be more beneficial than moderate-intensity continuous training (MICT). METHODS AND ANALYSIS: In this two-group parallel, open-label blinded endpoint randomised trial, 70 sedentary middle-aged (45-65 years) adults will be randomly allocated to one of two 12-week aerobic exercise training interventions matched for total exercise training volume: (1) MICT (n=35) or HIIT (n=35). Participants will perform ~50 min exercise training sessions, 3 days per week, for 12 weeks. The primary outcome will be measured as between-group difference in cardiorespiratory fitness (peak oxygen uptake) change from baseline to the end of training. Secondary outcomes include between-group differences in cognitive function and ultra-high field MRI (7T) measured markers of brain health (brain blood flow, cerebrovascular function, brain volume, white matter microstructural integrity and resting state functional brain activity) changes from baseline to the end of training. ETHICS AND DISSEMINATION: The Victoria University Human Research Ethics Committee (VUHREC) has approved this study (HRE20178), and all protocol modifications will be communicated to the relevant parties (eg, VUHREC, trial registry). Findings from this study will be disseminated via peer-review publications, conference presentations, clinical communications and both mainstream and social media. TRIAL REGISTRATION NUMBER: ANZCTR12621000144819.
Assuntos
Demência , Substância Branca , Pessoa de Meia-Idade , Adulto , Humanos , Encéfalo/diagnóstico por imagem , Cognição , Exercício FísicoRESUMO
Investigators in neuroscience have turned to Big Data to address replication and reliability issues by increasing sample sizes, statistical power, and representativeness of data. These efforts unveil new questions about integrating data arising from distinct sources and instruments. We focus on the most frequently assessed cognitive domain - memory testing - and demonstrate a process for reliable data harmonization across three common measures. We aggregated global raw data from 53 studies totaling N = 10,505 individuals. A mega-analysis was conducted using empirical bayes harmonization to remove site effects, followed by linear models adjusting for common covariates. A continuous item response theory (IRT) model estimated each individual's latent verbal learning ability while accounting for item difficulties. Harmonization significantly reduced inter-site variance while preserving covariate effects, and our conversion tool is freely available online. This demonstrates that large-scale data sharing and harmonization initiatives can address reproducibility and integration challenges across the behavioral sciences.
RESUMO
This study investigated how ownership identification accuracy and object preferences in children with autism spectrum disorder (ASD) are influenced by visual distinctiveness and relative desirability. Unlike typically developing (TD) children matched on receptive language (M age equivalents: 58.8-59.9 months), children with ASD had difficulty identifying another person's property when object discriminability was low and identifying their own relatively undesirable objects. Children with ASD identified novel objects designated to them with no greater accuracy than objects designated to others, and associating objects with the self did not bias their preferences. We propose that, due to differences in development of the psychological self, ownership does not increase the attentional or preferential salience of objects for children with ASD.
Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Humanos , Criança , Pré-Escolar , Transtorno Autístico/psicologia , Transtorno do Espectro Autista/psicologia , Propriedade , Desenvolvimento Infantil , AtençãoRESUMO
BACKGROUND: Type 2 diabetes (T2DM) is recognised as a major contributor to cognitive decline. People with T2DM demonstrate abnormalities on MRI compared to control individuals. The aim of this analysis was to investigate differences in cognitive performance and brain volume between individuals with T2DM participating in the Diabetes-and-Dementia (D2) study and a group of healthy controls (HC) part of the Cognition And Neocortical Volume After Stroke (CANVAS) study. METHOD: One hundred and fifty individuals with T2DM and 36 cognitively-normal participants completed neuropsychological assessments and a 3T-MRI scan. FreeSurfer was used to estimate total brain volume (TBV), mean cortical thickness and subcortical volumes, including the thalami and caudate nuclei. Averages between left and right volumes were calculated for subcortical structures. WMH volumes were estimated manually using FLAIR MRI. Five cognitive domains, including attention, visuospatial skills, memory, language and executive function were computed using z-scores. These domains were used to compare cognitive performance between individuals with and without T2DM. Demographic and clinical comparisons were completed in MATLAB using Two-Sample t-test (age), Fisher Exact test (education, sex, APOE-e4), and Wilcoxon Rank Sum test (BMI). A linear regression model was used to compare cognitive performance between the two groups with correction for age, sex and education level (more/less than 12 years), as well as total intracranial volume for comparing brain volumes. RESULT: Participants with T2DM were significantly younger, with a higher BMI, had reduced cortical thickness, significantly smaller TBV and smaller subcortical volumes including thalamic, brainstem, amygdala, accumbens area and choroid plexus. Individuals with T2DM exhibited a poorer cognitive performance on tests of language, memory, attention, and visuospatial skills compared to the HC group. There were no significant differences between the two groups in terms of sex, education level, APOE-e4 carriage, WMH, hippocampal volume (see Table 1). CONCLUSION: T2DM is associated with accelerated structural brain aging, manifesting as cerebral atrophy and poorer cognitive function.
Assuntos
Encéfalo , Diabetes Mellitus Tipo 2 , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Humanos , Masculino , Feminino , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Idoso , Encéfalo/patologia , Encéfalo/diagnóstico por imagem , Testes Neuropsicológicos/estatística & dados numéricos , Pessoa de Meia-Idade , Disfunção Cognitiva/patologia , Tamanho do Órgão , Cognição/fisiologiaRESUMO
Cue combination describes the use of two sensory cues together to increase perceptual precision. Internal relative bias describes a situation in which two cues to the same state of the world are perceived as signaling different states of the world on average. Current theory and evidence have difficulty accounting for many instances where cue combination is absent, such as in children under 10 years old, and in a variety of tasks. Here we show that internal relative biases between cues could be a key explanatory factor. Experiment 1, studying children's three-dimensional (slant) perception via disparity and texture, found a negative cross-sectional correlation between internal relative bias and cue combination behavior in 7- to 10-year-olds. Strikingly, children who had below-median levels of internal relative bias were able to combine cues, unlike the typical result for that age range. Experiment 2, studying adults' visual-auditory localization, found that cue combination behavior increased after an intervention designed to decrease internal relative bias. We interpret this as strong but preliminary evidence that internal relative bias can disrupt cue combination behavior. This provides a plausible mechanism to explain why children under 10 generally do not combine cues and why the audiovisual cue combination is so inconsistent in adults. Moving forward, we suggest that researchers who fail to find an expected cue combination effect should further investigate the possibility of issues with internal relative bias. Decreasing internal relative bias may also be an important goal for rehabilitation and sensory substitution or augmentation approaches to promoting efficient multisensory perception.
Assuntos
Sinais (Psicologia) , Adulto , Criança , Humanos , Estudos Transversais , ViésRESUMO
Knowledge of one's own body size is a crucial facet of body representation, both for acting on the environment and perhaps also for constraining body ownership. However, representations of body size may be somewhat plastic, particularly to allow for physical growth in childhood. Here we report a developmental investigation into the role of hand size in body representation (the sense of body ownership, perception of hand position, and perception of own-hand size). Using the rubber hand illusion paradigm, this study used different fake hand sizes (60%, 80%, 100%, 120% or 140% of typical size) in three age groups (6- to 7-year-olds, 12- to 13-year-olds, and adults; N = 229). We found no evidence that hand size constrains ownership or position: participants embodied hands which were both larger and smaller than their own, and indeed judged their own hands to have changed size following the illusion. Children and adolescents embodied the fake hands more than adults, with a greater tendency to feel their own hand had changed size. Adolescents were particularly sensitive to multisensory information. In sum, we found substantial plasticity in the representation of own-body size, with partial support for the hypothesis that children have looser representations than adults.
Assuntos
Ilusões , Percepção do Tato , Adulto , Criança , Adolescente , Humanos , Imagem Corporal , Propriocepção , Percepção Visual , MãosRESUMO
Cortical thinning has been described in many neurodegenerative diseases and used for both diagnosis and disease monitoring. The imaging signatures of post-stroke vascular cognitive impairment have not been well described. We investigated the trajectory of cortical thickness over 3 years following ischaemic stroke compared to healthy stroke-free age- and sex-matched controls. We also compared cortical thickness between cognitively normal and impaired stroke survivors, and between APOE É4 carriers and non-carriers. T1-weighted MRI and cognitive data for 90 stroke survivors and 36 controls from the Cognition And Neocortical Volume After Stroke (CANVAS) study were used. Cortical thickness was estimated using FreeSurfer volumetric reconstruction according to the Desikan-Killiany parcellation atlas. Segmentation inaccuracies were manually corrected and infarcted ipsilesional vertices in cortical thickness maps were identified and excluded using stroke lesion masks traced a-priori. Mixed-effects regression was used to compare cortical thickness cross-sectionally between groups and longitudinally between timepoints. Healthy control and stroke groups did not differ on demographics and most clinical characteristics, though controls were less likely to have atrial fibrillation. Age was negatively associated with global mean cortical thickness independent of sex or group, with women in both groups having significantly thicker cortex. Three months post-stroke, cortical thinning was limited and focal. From 3 months to 3 years, the rate of cortical thinning in stroke was faster compared to that in healthy controls. However, this difference in cortical thinning rate could not survive family-wise correction for multiple comparisons. Yet, cortical thinning at 3 years was found more spread especially in ipsilesional hemispheres in regions implicated in motor, sensory, and memory processing and recovery. The cognitively impaired stroke survivors showed greater cortical thinning, compared to controls, than those who were cognitively normal at 3 years. Also, carriers of the APOE É4 allele in stroke exhibited greater cortical thinning independent of cognitive status. The temporal changes of cortical thickness in both healthy and stroke cohorts followed previously reported patterns of cortical thickness asymmetry loss across the human adult life. However, this loss of thickness asymmetry was amplified in stroke. The post-stroke trajectories of cortical thickness reported in this study may contribute to our understanding of imaging signatures of vascular cognitive impairment.
Assuntos
Afinamento Cortical Cerebral , Disfunção Cognitiva , AVC Isquêmico , Adulto , Feminino , Humanos , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/patologia , Córtex Cerebral/patologia , Afinamento Cortical Cerebral/patologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/genética , AVC Isquêmico/complicações , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/patologia , Imageamento por Ressonância Magnética/métodos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismoRESUMO
Dynamic whole-brain changes occur following stroke, and not just in association with recovery. We tested the hypothesis that the presence of a specific behavioural deficit after stroke would be associated with structural decline (atrophy) in the brain regions supporting the affected function, by examining language deficits post-stroke. We quantified whole-brain structural volume changes longitudinally (3-12 months) in stroke participants with (N = 32) and without aphasia (N = 59) as assessed by the Token Test at 3 months post-stroke, compared with a healthy control group (N = 29). While no significant difference in language decline rates (change in Token Test scores from 3 to 12 months) was observed between groups and some participants in the aphasic group improved their scores, stroke participants with aphasia symptoms at 3 months showed significant atrophy (>2%, P = 0.0001) of the left inferior frontal gyrus not observed in either healthy control or non-aphasic groups over the 3-12 months period. We found significant group differences in the inferior frontal gyrus volume, accounting for age, sex, stroke severity at baseline, education and total intracranial volume (Bonferroni-corrected P = 0.0003). In a subset of participants (aphasic N = 14, non-aphasic N = 36, and healthy control N = 25) with available diffusion-weighted imaging data, we found significant atrophy in the corpus callosum and the left superior longitudinal fasciculus in the aphasic compared with the healthy control group. Language deficits at 3 months post-stroke are associated with accelerated structural decline specific to the left inferior frontal gyrus, highlighting that known functional brain reorganization underlying behavioural improvement may occur in parallel with atrophy of brain regions supporting the language function.
RESUMO
PURPOSE: White matter hyperintensities (WMHs) are associated with poststroke cognitive decline and mortality. Physical activity (PA) may decrease WMH risk by reducing vascular risk factors and promoting cerebral perfusion. However, the association between poststroke PA and WMH progression remains unclear. We examined the association between PA and WMH volume 12 months after stroke, and between PA and change in WMH volume between 3 and 12 months after stroke. METHODS: We included ischemic stroke survivors from the Cognition And Neocortical Volume After Stroke cohort with available brain magnetic resonance imaging and objective PA data. Total, periventricular, and deep WMH volumes (in milliliters) were estimated with manually edited, automated segmentations (Wisconsin White Matter Hyperintensities Segmentation toolbox). Moderate-to-vigorous intensity PA (MVPA) was estimated using the SenseWear® Armband. Participants with MVPA ≥30 min·d -1 were classified as "meeting PA guidelines." We used quantile regression to estimate the associations between PA (MVPA and meeting PA guidelines) with WMH volume at 12 months and change in WMH volume between 3 and 12 months after stroke. RESULTS: A total of 100 participants were included (median National Institutes of Health Stroke Scale 2; interquartile range, 1-4). MVPA was not associated with WMH volume. In univariable analysis, meeting PA guidelines was associated with lower total, periventricular, and deep WMH volumes by 3.0 mL (95% confidence interval (CI), 0.5-9.7 mL), 2.8 mL (95% CI, 0.5-7.1 mL), and 0.9 mL (95% CI, 0.1-3.0 mL), respectively. However, in multivariable analysis, meeting PA guidelines was not associated with WMH volume, and older age was associated with greater WMH volume at 12 months. PA was not associated with change in WMH volume. CONCLUSIONS: Meeting PA guidelines was associated with lower WMH volume at 12 months in univariable analysis, but not in multivariable analysis. Age consistently predicted greater WMH volume.
Assuntos
Acidente Vascular Cerebral , Substância Branca , Encéfalo/diagnóstico por imagem , Cognição , Exercício Físico , Humanos , Imageamento por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologiaRESUMO
OBJECTIVES: Cognitive and mood dysfunction are major contributors to post-stroke disability. The longer-term trajectories of mood and cognition post-stroke remain unclear, as do which cognitive domains decline, improve, or remain stable after stroke, and in which patients. We aimed to characterize the cognitive trajectories of mild ischemic stroke survivors over one year compared to stroke-free controls, and to investigate whether symptoms of anxiety and depression were associated with cognitive function. MATERIALS AND METHODS: All participants were tested with a neuropsychological test battery at 3-months and 12-months post-stroke, assessing attention/processing speed, memory, visuospatial function, executive function, and language. Anxiety and depression symptomatology were also assessed at both timepoints. RESULTS: Stroke participants (N=126, mean age 68.44 years ±11.83, 87 males, median [Q1, Q3] admission NIHSS=2 [1, 4]) performed worse on cognitive tests and endorsed significantly higher depression and anxiety symptomatology than controls (N=40, mean age=68.82 years ±6.33, 25 males) at both timepoints. Mood scores were not correlated with cognitive performance. Stroke participants' scores trended higher across cognitive domains from 3- to 12-months but statistically significant improvement was only observed on executive function tasks. CONCLUSION: Stroke participants performed significantly worse than controls on all cognitive domains following mild ischemic stroke. Stroke participants only exhibited statistically significant improvement on executive function tasks between 3- and 12- months. Whilst anxiety and depression symptoms were higher in stroke participants, this was not correlated with cognitive performance. Further studies are needed to understand factors underlying cognitive recovery and decline after stroke.
Assuntos
Disfunção Cognitiva , AVC Isquêmico , Acidente Vascular Cerebral , Afeto , Idoso , Cognição , Disfunção Cognitiva/complicações , Disfunção Cognitiva/etiologia , Função Executiva , Humanos , Masculino , Testes Neuropsicológicos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnósticoRESUMO
BACKGROUND: The structural integrity of hippocampal subfields has been investigated in many neurological disorders and was shown to be better associated with cognitive performance than whole hippocampus. In stroke, hippocampal atrophy is linked to cognitive impairment, but it is unknown whether the hippocampal subfields atrophy differently. PURPOSE: To evaluate longitudinal hippocampal subfield atrophy in first year poststroke, in comparison with atrophy in healthy individuals. STUDY TYPE: Cohort. SUBJECTS: A total of 92 ischemic stroke (age: 67 ± 12 years, 63 men) and 39 healthy participants (age: 69 ± 7 years, 24 men). FIELD STRENGTH/SEQUENCE: A3 T/T1-MPRAGE, T2-SPACE, and T2-FLAIR. ASSESSMENT: FreeSurfer (6.0) was used to delineate 12 hippocampal subfields. Whole hippocampal volume was computed as sum of subfield volumes excluding hippocampal fissure volume. Separate assessments were completed for contralesional and ipsilesional hippocampi. STATISTICAL TESTS: A mixed-effect regression model was used to compare subfield volumes cross-sectionally between healthy and stroke groups and longitudinally between 3-month and 12-month timepoints. False discovery rate at 0.05 significance level was used to correct for multiple comparisons. Also, a receiver operating characteristic (ROC) curve analysis was performed to assess differentiation between healthy and stroke participants based on subfield volumes. RESULTS: There were no volume differences between groups at 3 months, but there was a significant difference (P = 0.027) in whole hippocampal volume reduction over time between control and stroke ipsilesionally. Thus, the ipsilesional whole hippocampal volume in stroke became significantly smaller (P = 0.035) at 12 months. The hippocampal tail was the highest single-region contributor (22.7%) to ipsilesional hippocampal atrophy (1.19%) over 9 months. The cornu ammonis areas (CA1) subfield volume reduction was minimal in controls and stroke contralesionally but significant ipsilesionally (P = 0.007). CA1 volume significantly outperformed whole hippocampal volume (P < 0.01) in discriminating between stroke participants and healthy controls in ROC curve analysis. DATA CONCLUSION: Greater stroke-induced effects were observed in the ipsilesional hippocampus anteriorly in CA1 and posteriorly in the hippocampal tail. Atrophy of CA1 and hippocampal tail may provide a better link to cognitive impairment than whole hippocampal atrophy. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.
Assuntos
Disfunção Cognitiva , AVC Isquêmico , Idoso , Atrofia/patologia , Disfunção Cognitiva/patologia , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-IdadeRESUMO
INTRODUCTION: The Digit-Symbol-Substitution Test (DSST) is used widely in neuropsychological investigations of Alzheimer's Disease (AD). A computerized version of this paradigm, the DSST-Meds, utilizes medicine-date pairings and has been developed for administration in both supervised and unsupervised environments. This study determined the utility and validity of the DSST-Meds for measuring cognitive dysfunction in early AD. METHOD: Performance on the DSST-Meds was compared to performance on the WAIS Coding test, and a computerized digit symbol coding test (DSST-Symbols). The first study compared supervised performance on the three DSSTs versions in cognitively unimpaired (CU) adults (n = 104). The second compared supervised DSST performance between CU (n = 60) and mild-symptomatic AD (mild-AD, n = 79) groups. The third study compared performance on the DSST-Meds between unsupervised (n= 621) and supervised settings. RESULTS: In Study 1, DSST-Meds accuracy showed high correlations with the DSST-Symbols accuracy (r = 0.81) and WAIS-Coding accuracy (r = 0.68). In Study 2, when compared to CU adults, the mild-AD group showed lower accuracy on all three DSSTs (Cohen's d ranging between 1.39 and 2.56) and DSST-Meds accuracy was correlated moderately with Mini-Mental State Examination scores (r = 0.44, p < .001). Study 3 observed no difference in DSST-meds accuracy between supervised and unsupervised administrations. CONCLUSION: The DSST-Meds showed good construct and criterion validity when used in both supervised and unsupervised contexts and provided a strong foundation to investigate the utility of the DSST in groups with low familiarity to neuropsychological assessment.
Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Adulto , Humanos , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Testes NeuropsicológicosRESUMO
Introduction: Coronavirus (COVID-19) instigated unprecedented global effects on healthcare systems, economies, employment, education, travel, and social lives. In addition to increased mental health challenges, pandemic restrictions have triggered emerging cognitive concerns. University students are at particularly high risk of adverse lockdown-related effects, yet despite the substantial adaptions to learning necessitated by COVID-19, limited research has so far focused on the cognitive consequences of the pandemic among university students. This study aimed to comprehensively examine the nature, prevalence, and correlates of subjective cognitive concerns among 972 students (Median age = 22âyears, 70% female) enrolled at Monash University, Australia, in December 2020. Methods: Students completed the online THRIVE@Monash survey, 5âweeks following prolonged lockdown in Melbourne. Using group comparisons and hierarchical binary logistic regression analyses, we examined associations between demographic and enrolment characteristics, COVID-19-related experiences and impacts (author-developed questions), self-reported anxiety and depression symptoms (PROMIS Anxiety and Depression scales), and students' perceived changes in everyday cognitive functions (author-developed questions). Results: Over 60% of students reported subjective cognitive concerns (SCCs). After controlling for anxiety and depression symptoms, students reporting more SCCs were more likely to be younger, from White/European ethnic backgrounds, and in their first year of undergraduate study. No differences in SCCs were found between male and female students. Greater worry, anxiety, or stress related to COVID-19 (e.g., infection, leaving the house, hygiene and exposure prevention, impact on physical and mental health), and time spent reading or talking about COVID-19, were generally not associated with SCCs after controlling for anxiety and depression symptoms. Discussion: These findings highlight vulnerable subgroups of students who might benefit from regular monitoring, education, and interventions to support their cognitive health during the pandemic and beyond. In addition, cognitive concerns may provide additional insight into mental health problems among students, and emphasize the importance of understanding factors that impact students' long-term academic and career success.
RESUMO
There are vast potential applications for children's entertainment and education with modern virtual reality (VR) experiences, yet we know very little about how the movement or form of such a virtual body can influence children's feelings of control (agency) or the sensation that they own the virtual body (ownership). In two experiments, we gave a total of 197 children aged 4-14 years a virtual hand which moved synchronously or asynchronously with their own movements and had them interact with a VR environment. We found that movement synchrony influenced feelings of control and ownership at all ages. In Experiment 1 only, participants additionally felt haptic feedback either congruently, delayed or not at all - this did not influence feelings of control or ownership. In Experiment 2 only, participants used either a virtual hand or non-human virtual block. Participants embodied both forms to some degree, provided visuomotor signals were synchronous (as indicated by ownership, agency, and location ratings). Yet, only the hand in the synchronous movement condition was described as feeling like part of the body, rather than like a tool (e.g., a mouse or controller). Collectively, these findings highlight the overall dominance of visuomotor synchrony for children's own-body representation; that children can embody non-human forms to some degree; and that embodiment is also somewhat constrained by prior expectations of body form.
Assuntos
Gráficos por Computador , Realidade Virtual , Mãos , Movimento , HumanosRESUMO
Background: Stroke survivors are at high risk of dementia, associated with increasing age and vascular burden and with pre-existing cognitive impairment, older age. Brain atrophy patterns are recognised as signatures of neurodegenerative conditions, but the natural history of brain atrophy after stroke remains poorly described. We sought to determine whether stroke survivors who were cognitively normal at time of stroke had greater total brain (TBV) and hippocampal volume (HV) loss over 3 years than controls. We examined whether stroke survivors who were cognitively impaired (CI) at 3 months following their stroke had greater brain volume loss than cognitively normal (CN) stroke participants over the next 3 years. Methods: Cognition And Neocortical Volume After Stroke (CANVAS) study is a multi-centre cohort study of first-ever or recurrent adult ischaemic stroke participants compared to age- and sex-matched community controls. Participants were followed with MRI and cognitive assessments over 3 years and were free of a history of cognitive impairment or decline at inclusion. Our primary outcome measure was TBV change between 3 months and 3 years; secondary outcomes were TBV and HV change comparing CI and CN participants. We investigated associations between group status and brain volume change using a baseline-volume adjusted linear regression model with robust standard error. Results: Ninety-three stroke (26 women, 66.7 ± 12 years) and 39 control participants (15 women, 68.7 ± 7 years) were available at 3 years. TBV loss in stroke patients was greater than controls: stroke mean (M) = 20.3 cm3 ± SD 14.8 cm3; controls M = 14.2 cm3 ± SD 13.2 cm3; [adjusted mean difference 7.88 95%CI (2.84, 12.91) p-value = 0.002]. TBV decline was greater in those stroke participants who were cognitively impaired (M = 30.7 cm3; SD = 14.2 cm3) at 3 months (M = 19.6 cm3; SD = 13.8 cm3); [adjusted mean difference 10.42; 95%CI (3.04, 17.80), p-value = 0.006]. No statistically significant differences in HV change were observed. Conclusions: Ischaemic stroke survivors exhibit greater neurodegeneration compared to stroke-free controls. Brain atrophy is greater in stroke participants who were cognitively impaired early after their stroke. Early cognitive impairment was associated greater subsequent atrophy, reflecting the combined impacts of stroke and vascular brain burden. Atrophy rates could serve as a useful biomarker for trials testing interventions to reduce post-stroke secondary neurodegeneration. Clinical Trail Registration: http://www.clinicaltrials.gov, identifier: NCT02205424.