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1.
Neuropsychol Rev ; 32(2): 274-293, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33886024

RESUMO

The relationship between cognitive function and frailty among older adults is a growing area of research due to the implications of cognitive and physical decline for functional independence in late life. Multiple studies demonstrate a meaningful relationship between these two factors, which together may constitute increased risk of negative health outcomes for older adults. The current analysis was conducted to 1) systematically review current evidence for differences in cognitive performance based on frailty status among older adults and provide quantitative evidence for the magnitude of this effect, and 2) assess the influence of demographic and methodological variables on this effect. The preregistered protocol (CRD42018087138) included a search of EBSCOhost, Pubmed, and Embase online databases and reference lists to identify cross-sectional studies comparing frail and non-frail or robust older adults (60+) on cognitive performance. In total, 42 effects were retrieved from 38 studies, expressed as Hedges' g, and pooled based on a random-effects model. Results indicated an overall significant, negative effect of frailty status on cognitive function among tests of global cognitive function (g = 0.734: 95% CI = 0.601-0.867) and individual cognitive domains (g = 0.439: 95% CI = 0.342-0.535). Age, frailty assessment used, and cognitive status of the sample did not significantly moderate the overall effect. Post-hoc moderator analysis revealed that difference in mean age of frail and robust groups significantly moderated the overall effect (R2 = 0.38, ß = .0974, 95% CI = 0.0537-0.141). Implications for future research are discussed.


Assuntos
Fragilidade , Idoso , Cognição , Estudos Transversais , Idoso Fragilizado , Humanos
2.
Clin Gerontol ; 45(3): 722-732, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-32543295

RESUMO

Objectives: The current study sought to evaluate the relationship between cognitive performance and Instrumental Activities of Daily Living (IADL) performance in a population of community dwelling older adults, and assess to what extent this relationship is moderated by cognitive reserve (Premorbid-IQ)Methods: 123 community-dwelling older adults completed a general cognitive assessment, a word-reading based premorbid-IQ estimate (PMIQE) measure, and the performance-based Direct Assessment of Functional Status, Revised (DAFS-R). Moderated regression analysis was used to assess the influence of PMIQE on the relationship between cognitive performance and IADLs.Results: There was a significant main effect of cognitive performance on IADLs, and no main effect of PMIQE on functional IADLs. There was a significant moderating effect of PMIQE on the relationship between cognitive performance and IADLs performance, such that at higher levels of PMIQE, cognitive performance scores became slightly less predictive of weaknesses in IADLs.Conclusions: Results suggest that for individuals with high reserve, assessment of cognitive performance alone may not be robust a predictor of IADLs functioning.Clinical implications: In estimating functional abilities as a consequence of cognitive performance, consideration should be given to premorbid-IQ/cognitive reserve.


Assuntos
Atividades Cotidianas , Reserva Cognitiva , Atividades Cotidianas/psicologia , Idoso , Estado Funcional , Humanos , Vida Independente , Análise de Regressão
3.
Health Promot Pract ; 22(5): 649-658, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32443945

RESUMO

Concussion education have served as a keystone for improving concussion reporting. Numerous factors affecting concussion reporting have been explored; however, the role of socioeconomic status (SES) in reporting has not been established. We examined the influence of SES and academic achievement (high-school grade point average [HS-GPA] and American College Testing [ACT] composite scores) on athletes' concussion-reporting intentions and behaviors. A cross-sectional study was employed among 191 athletes (94 female; age 19.3 ± 1.2 years). Athletes reported SES metrics (parental education and occupation, household income, HS-GPA, and ACT composite score) prior to their athletic season and completed a survey assessing symptom- and concussion-reporting intentions. Symptom- and concussion-reporting behaviors were assessed among athletes who experienced a concussion within the past year. SES was determined using the Hollingshead Four-Factor Index grouping athletes into SES strata. Athletes were grouped into low/high categories for academic achievement and household income variables. The 191 athletes were included for symptom- and concussion-reporting intentions analyses, while 46 and 41 were included for symptom- and concussion-reporting behavior, respectively. Nonparametric statistics with false discovery rate adjusted p values were employed. We found symptom- and concussion-reporting intentions, and symptom- and concussion-reporting behaviors were not significantly different based on SES strata (all p values ≥.64), household income (all p values ≥.64), HS-GPA (all p values ≥.24), or ACT scores (all p values ≥.25). Overall, SES and academic achievement may not play a role in understanding concussion reporting among middle- to high-SES collegiate athletes. Implementing policies targeting certain SES and academic levels might be an ineffective health care strategy for increasing reporting.


Assuntos
Sucesso Acadêmico , Traumatismos em Atletas , Concussão Encefálica , Adolescente , Adulto , Atletas , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/epidemiologia , Concussão Encefálica/diagnóstico , Estudos Transversais , Feminino , Humanos , Intenção , Classe Social , Adulto Jovem
4.
J Int Neuropsychol Soc ; 25(9): 950-960, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31383046

RESUMO

OBJECTIVE: Multiple concussions sustained in youth sport may be associated with later-life brain changes and worse cognitive outcomes. We examined the association between two or more concussions during high school football and later-life white matter (WM) microstructure (i.e., 22-47 years following football retirement) using diffusion tensor imaging (DTI). METHOD: Forty former high school football players aged 40-65 who received 2+ concussions during high school football (N = 20), or denied concussive events (N = 20) were recruited. Participants underwent neurocognitive testing and DTI scanning. RESULTS: Groups did not statistically differ on age, education, or estimated pre-morbid intelligence. Tract-based Spatial Statistics (TBSS) correcting for Family-Wise Error (FWE)(p < .05) did not yield differences between groups at the whole-brain level. Region of interest analyses showed higher mean diffusivity (MD) in the anterior limb of the internal capsule (ALIC) in the concussed group compared to the non-concussed former players. More liberal analyses (i.e., p < .001, uncorrected for multiple comparisons, ≥8 voxels) also revealed that former players endorsing 2+ concussions had higher MD in the ALIC. Analyses that covaried for age did not reveal differences at either threshold. Concussive histories were not associated with worse cognitive functioning, nor did it impact the relationship between neuropsychological scores and DTI metrics. DISCUSSION: Results suggest only minimal neuroanatomical brain differences in former athletes many years following original concussive injuries compared to controls.


Assuntos
Traumatismos em Atletas/patologia , Concussão Encefálica/patologia , Futebol Americano/lesões , Cápsula Interna/patologia , Substância Branca/patologia , Adulto , Idoso , Traumatismos em Atletas/diagnóstico por imagem , Traumatismos em Atletas/fisiopatologia , Concussão Encefálica/diagnóstico por imagem , Concussão Encefálica/fisiopatologia , Imagem de Tensor de Difusão , Seguimentos , Humanos , Cápsula Interna/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Substância Branca/diagnóstico por imagem
5.
Int Psychogeriatr ; 31(4): 455-465, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30786950

RESUMO

ABSTRACTObjectives:Centenarians have survived into very late life, but whether they reach very old age in good health remains unclear. The purpose of this study was to compare the cardiovascular health status and cognitive functioning of centenarians in the United States with centenarians in Japan. DESIGN, SETTING, AND PARTICIPANTS: This cross-national design compared centenarians from the United States and Japan. The sample of U.S. centenarians was recruited from the Georgia Centenarian Study and included 287 centenarians. The sample of Japanese centenarians was recruited from the Tokyo Centenarian Study and included 304 centenarians. MEASUREMENTS: Cognitive functioning was assessed with a mental status questionnaire, and cardiovascular disease by a health history assessment, blood pressure, and selected blood parameters. RESULTS: The results suggest that Tokyo centenarians had lower disease experiences and BMI values, when compared to Georgia centenarians, but blood pressure was higher among Japanese centenarians. Lower levels of hemoglobin in Japanese centenarians and higher levels of C-reactive protein in Georgia were also found. The positive association of hypertension and albumin levels with cognitive functioning and the negative association of stroke occurrence with cognitive functioning were replicated in both countries. Differential effects were obtained for heart problems, BMI, and C-reactive protein (with positive effects for Tokyo centenarians, except for C-reactive protein). CONCLUSION: For extremely old individuals, some markers of cardiovascular disease are replicable across countries, whereas differential effects for cardiovascular health also need to be considered in cardiovascular health.


Assuntos
Envelhecimento , Doenças Cardiovasculares , Cognição , Nível de Saúde , Hipertensão , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Envelhecimento/psicologia , Índice de Massa Corporal , Proteína C-Reativa/análise , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Comparação Transcultural , Feminino , Georgia/epidemiologia , Avaliação Geriátrica/métodos , Avaliação Geriátrica/estatística & dados numéricos , Humanos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Japão/epidemiologia , Masculino , Testes de Estado Mental e Demência/estatística & dados numéricos
6.
Brain Inj ; 33(5): 592-597, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30704294

RESUMO

PRIMARY OBJECTIVE: The objective of this study was to determine whether sex, years of sport eligibility completed, and sport contact level influenced student-athletes' concussion reporting intentions and behaviours. RESEARCH DESIGN: Cross-sectional. METHODS AND PROCEDURES: Student-athletes (n = 828) reported their sex, years of sport eligibility completed, sport, and completed concussion reporting intentions and behaviours surveys. Nonparametric statistics were conducted to compare intentions and behaviours between groups (alpha = 0.05). MAIN OUTCOMES AND RESULTS: Females had higher indirect intentions to report concussion than males (p = 0.035), but did not differ in direct intentions (p = 0.258) or behaviours (indirect: p = 0.756; direct: p = 0.686). Intentions (indirect: p = 0.383; direct: p = 0.397) and behaviours (indirect: p = 0.154; direct: p = 0.999) did not differ between years of sport eligibility completed. Limited/non-contact sport student-athletes intended to report more concussions than those in collision/contact sports (indirect: p = 0.001; direct: p = 0.021), but did not differ in behaviours (indirect: p = 0.184; direct: p = 0.497). CONCLUSIONS: Data suggest that female and limited/non-contact sport student-athletes intended to report more concussions, however differences did not translate to reporting behaviours.


Assuntos
Atletas/psicologia , Traumatismos em Atletas/diagnóstico , Concussão Encefálica/diagnóstico , Conhecimentos, Atitudes e Prática em Saúde , Intenção , Adolescente , Estudos Transversais , Feminino , Humanos , Masculino , Fatores Sexuais , Esportes , Universidades , Adulto Jovem
7.
J Int Neuropsychol Soc ; 24(1): 77-90, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28695791

RESUMO

OBJECTIVES: The present study constitutes the first randomized controlled trial to investigate the relation of lutein (L) and zeaxanthin (Z) to brain function using functional magnetic resonance imaging (fMRI). It was hypothesized that L and Z supplementation in older adults would enhance neural efficiency (i.e., reduce activation) and cognitive performance on a verbal learning task relative to placebo. METHODS: A total of 44 community-dwelling older adults (mean age=72 years) were randomly assigned to receive either placebo or L+Z supplementation (12 mg/daily) for 1 year. Neurocognitive performance was assessed at baseline and post-intervention on an fMRI-adapted task involving learning and recalling word pairs. Imaging contrasts of blood-oxygen-level-dependent (BOLD) signal were created by subtracting active control trials from learning and recall trials. A flexible factorial model was employed to investigate the expected group (placebo vs. supplement) by time (baseline vs. post-intervention) interaction in pre-specified regions-of-interest. RESULTS: L and Z appeared to buffer cognitive decline on the verbal learning task (Cohen's d=.84). Significant interactions during learning were observed in left dorsolateral prefrontal cortex and anterior cingulate cortex (p < .05, family-wise-error corrected). However, these effects were in the direction of increased rather than decreased BOLD signal. Although the omnibus interaction was not significant during recall, within-group contrasts revealed significant increases in left prefrontal activation in the supplement group only. CONCLUSIONS: L and Z supplementation appears to benefit neurocognitive function by enhancing cerebral perfusion, even if consumed for a discrete period of time in late life. (JINS, 2018, 24, 77-90).


Assuntos
Envelhecimento/fisiologia , Disfunção Cognitiva/prevenção & controle , Disfunção Cognitiva/fisiopatologia , Suplementos Nutricionais , Giro do Cíngulo/fisiologia , Luteína/farmacologia , Córtex Pré-Frontal/fisiologia , Aprendizagem Verbal/fisiologia , Zeaxantinas/farmacologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/efeitos dos fármacos , Disfunção Cognitiva/diagnóstico por imagem , Feminino , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/efeitos dos fármacos , Humanos , Vida Independente , Luteína/administração & dosagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/efeitos dos fármacos , Aprendizagem Verbal/efeitos dos fármacos , Zeaxantinas/administração & dosagem
8.
J Int Neuropsychol Soc ; 23(1): 11-22, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27776568

RESUMO

OBJECTIVES: It is well known that the carotenoids lutein (L) and zeaxanthin (Z) improve eye health and an accumulating evidence base suggests cognitive benefits as well. The present study investigated underlying neural mechanisms using functional magnetic resonance imaging (fMRI). It was hypothesized that lower L and Z concentrations would be associated with neurobiological inefficiency (i.e., increased activation) during cognitive performance. METHODS: Forty-three community-dwelling older adults (mean age=72 years; 58% female; 100% Caucasian) were asked to learn and recall pairs of unrelated words in an fMRI-adapted paradigm. L and Z levels were measured in retina (macular pigment optical density) and serum using validated procedures. RESULTS: Following first-level contrasts of encoding and retrieval trials minus control trials (p<.05, family-wise error corrected, minimum voxel cluster=8), L and Z were found to significantly and negatively relate to blood-oxygen-level-dependent signal in central and parietal operculum cortex, inferior frontal gyrus, supramarginal gyrus, planum polare, frontal and middle temporal gyrus, superior parietal lobule, postcentral gyrus, precentral gyrus, occipital cortex bilaterally, and cerebellar regions. CONCLUSIONS: To the authors' knowledge, the present study represents the first attempt to investigate neural mechanisms underlying the relation of L and Z to cognition using fMRI. The observed results suggest that L and Z promote cognitive functioning in old age by enhancing neural efficiency. (JINS, 2017, 23, 11-22).


Assuntos
Envelhecimento/sangue , Encéfalo/diagnóstico por imagem , Envelhecimento Cognitivo , Luteína/sangue , Imageamento por Ressonância Magnética , Zeaxantinas/sangue , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Mapeamento Encefálico , Depressão/sangue , Depressão/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Vida Independente , Pigmento Macular/metabolismo , Masculino , Testes Neuropsicológicos , Oxigênio/sangue , Leitura , Aprendizagem Verbal
9.
Neuropsychol Rev ; 26(2): 129-59, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27393566

RESUMO

Accumulating evidence suggests that the pre-dementia syndrome mild cognitive impairment (MCI) is characterized by decrements in instrumental activities of daily living (IADL). The current review was a quantitative synthesis of the available literature to objectively characterize IADL disability in MCI while clarifying inconsistencies in findings across studies. It was hypothesized that individuals with MCI would display significantly greater functional impairment relative to cognitively intact controls. Candidate moderators specified a priori included functional assessment approach, MCI subtype, depressive symptoms, and language conducted. Online databases (PubMed/MEDLINE and PsycINFO) and reference lists were searched to identify peer-reviewed publications assessing IADL in MCI compared to normal aging. A total of 151 effect sizes derived from 106 studies met inclusionary criteria (N = 62,260). Random effects models yielded a large overall summary effect size (Hedges' g = 0.76, 95 % confidence interval: 0.68 - 0.83, p < .001) confirmed in multi-level analyses adjusted for nesting of effect sizes within studies (g = 0.78, 95 % confidence interval: 0.69 - 0.87). Functional assessment strategy and MCI subtype were significant moderators of effect size, whereas depressive symptoms and language were not. Results convincingly demonstrate that MCI is associated with significant difficulties in the performance of complex everyday tasks. It appears that functional decline, like cognitive decline, exists on a continuum from healthy aging to dementia onset. Implications for clinical practice and research priorities are discussed.


Assuntos
Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Atividades Cotidianas , Depressão , Humanos , Idioma
10.
Int J Geriatr Psychiatry ; 30(9): 950-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25565648

RESUMO

OBJECTIVES: Extant research has established several predictors of functional ability (FA) in older adults (OAs); however, one factor that has been relatively ignored is personality. Preliminary evidence suggests that openness and agreeableness are associated with instrumental activities of daily living (IADLs). However, how personality is related to IADLs remains unclear. We aimed to determine how personality factors predict performance of IADLs, which we hypothesized, was because of executive functioning (EF). METHODS: To best understand the relationship between personality and IADLs, we recruited and ran 65 independent community dwelling OAs. Bivariate correlations and hierarchical regressions were completed to determine the associations between openness and agreeableness with IADLs. Lastly, mediation analyses were completed to examine our hypothesis that EF would mediate this relationship RESULTS: Correlation and regression findings support the relationship between openness and IADLs but not agreeableness and IADLs. As hypothesized, the relationship between openness and IADLs was mediated by EF. CONCLUSIONS: We replicated the relationship between openness and IADLs and extend the literature by showing the mechanism of action for this relationship is EF. While our mediation results support this perspective, future research should determine if interventions that increase OAs' EF, in turn, increase or attenuate decline in IADLs over time.


Assuntos
Atividades Cotidianas/psicologia , Personalidade , Idoso , Idoso de 80 Anos ou mais , Atitude , Função Executiva/fisiologia , Feminino , Avaliação Geriátrica/métodos , Humanos , Vida Independente/psicologia , Masculino , Testes Neuropsicológicos , Análise de Regressão
11.
Hum Brain Mapp ; 35(7): 2911-23, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24123412

RESUMO

Mild cognitive impairment (MCI) has received increasing attention not only because of its potential as a precursor for Alzheimer's disease but also as a predictor of conversion to other neurodegenerative diseases. Although MCI has been defined clinically, accurate and efficient diagnosis is still challenging. Although neuroimaging techniques hold promise, compared to commonly used biomarkers including amyloid plaques, tau protein levels and brain tissue atrophy, neuroimaging biomarkers are less well validated. In this article, we propose a connectomes-scale assessment of structural and functional connectivity in MCI via two independent multimodal DTI/fMRI datasets. We first used DTI-derived structural profiles to explore and tailor the most common and consistent landmarks, then applied them in a whole-brain functional connectivity analysis. The next step fused the results from two independent datasets together and resulted in a set of functional connectomes with the most differentiation power, hence named as "connectome signatures." Our results indicate that these "connectome signatures" have significantly high MCI-vs-controls classification accuracy, at more than 95%. Interestingly, through functional meta-analysis, we found that the majority of "connectome signatures" are mainly derived from the interactions among different functional networks, for example, cognition-perception and cognition-action domains, rather than from within a single network. Our work provides support for using functional "connectome signatures" as neuroimaging biomarkers of MCI.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/patologia , Disfunção Cognitiva/patologia , Conectoma , Vias Neurais/irrigação sanguínea , Vias Neurais/patologia , Idoso , Idoso de 80 Anos ou mais , Conjuntos de Dados como Assunto , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio , Máquina de Vetores de Suporte
12.
J Geriatr Psychiatry Neurol ; 27(4): 253-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24763070

RESUMO

Older adults (OAs) with mild cognitive impairment (MCI) are traditionally thought to have preservation of activities of daily living (ADLs). However, recent evidence suggests OAs with MCI may have difficulty completing ADLs and specifically instrumental ADLs (IADLs). The ADLs are frequently evaluated through self- or collateral report questionnaires, while performance-based measures are infrequently utilized, despite the decreased bias and increased accuracy and sensitivity associated with these instruments. This investigation compared ADLs between community-dwelling OAs with (n = 20) and without MCI (n = 30) using a self-report questionnaire (Older American Resources and Services Activities of Daily Living Scale; OARS), a collateral report questionnaire (OARS), and a performance-based measure (the Direct Assessment of Functional Status-Revised). Consistent with our hypothesis, OAs with MCI had decreased ADLs and IADLs on the performance-based measure compared to cognitively intact OAs, while there were no differences in ADLs or IADLs on self-report questionnaires or collateral report questionnaires. Our results suggest OAs with MCI have decreased ability to complete IADLs. However, this investigation suggests these deficits may not be detected by questionnaires and are more likely to be found with performance-based testing.


Assuntos
Atividades Cotidianas/psicologia , Cognição , Disfunção Cognitiva/diagnóstico , Avaliação Geriátrica/métodos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Envelhecimento/psicologia , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Função Executiva , Feminino , Georgia , Humanos , Masculino , Testes Neuropsicológicos , Inquéritos e Questionários , Análise e Desempenho de Tarefas , Pensamento
13.
Cereb Cortex ; 23(4): 786-800, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22490548

RESUMO

Is there a common structural and functional cortical architecture that can be quantitatively encoded and precisely reproduced across individuals and populations? This question is still largely unanswered due to the vast complexity, variability, and nonlinearity of the cerebral cortex. Here, we hypothesize that the common cortical architecture can be effectively represented by group-wise consistent structural fiber connections and take a novel data-driven approach to explore the cortical architecture. We report a dense and consistent map of 358 cortical landmarks, named Dense Individualized and Common Connectivity-based Cortical Landmarks (DICCCOLs). Each DICCCOL is defined by group-wise consistent white-matter fiber connection patterns derived from diffusion tensor imaging (DTI) data. Our results have shown that these 358 landmarks are remarkably reproducible over more than one hundred human brains and possess accurate intrinsically established structural and functional cross-subject correspondences validated by large-scale functional magnetic resonance imaging data. In particular, these 358 cortical landmarks can be accurately and efficiently predicted in a new single brain with DTI data. Thus, this set of 358 DICCCOL landmarks comprehensively encodes the common structural and functional cortical architectures, providing opportunities for many applications in brain science including mapping human brain connectomes, as demonstrated in this work.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Fibras Nervosas Mielinizadas/fisiologia , Vias Neurais/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Algoritmos , Atenção/fisiologia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/irrigação sanguínea , Imagem de Difusão por Ressonância Magnética , Emoções/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Semântica
14.
Cereb Cortex ; 22(12): 2831-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22190432

RESUMO

Convoluted cortical folding and neuronal wiring are 2 prominent attributes of the mammalian brain. However, the macroscale intrinsic relationship between these 2 general cross-species attributes, as well as the underlying principles that sculpt the architecture of the cerebral cortex, remains unclear. Here, we show that the axonal fibers connected to gyri are significantly denser than those connected to sulci. In human, chimpanzee, and macaque brains, a dominant fraction of axonal fibers were found to be connected to the gyri. This finding has been replicated in a range of mammalian brains via diffusion tensor imaging and high-angular resolution diffusion imaging. These results may have shed some lights on fundamental mechanisms for development and organization of the cerebral cortex, suggesting that axonal pushing is a mechanism of cortical folding.


Assuntos
Axônios/ultraestrutura , Córtex Cerebral/ultraestrutura , Macaca/anatomia & histologia , Vias Neurais/ultraestrutura , Pan troglodytes/anatomia & histologia , Animais , Feminino , Humanos , Masculino , Especificidade da Espécie , Adulto Jovem
15.
Exp Aging Res ; 39(2): 125-44, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23421635

RESUMO

UNLABELLED: BACKGROUND/STUDY CONTEXT: The goal of the study was to identify and characterize latent profiles (clusters) of cognitive functioning in centenarians and the psychometric properties of cognitive measures within them. METHODS: Data were collected from cross-sectional, population-based sample of 244 centenarians (aged 98 to 108, 15.8% men, 20.5% African American, 38.0% community-dwelling) from 44 counties in northern Georgia participating in the Georgia Centenarian Study (2001-2008). Measures included the Mini-Mental State Examination (MMSE), Severe Impairment Battery (SIB), Wechsler Adult Intelligence Scale-III Similarities subtest (WAIS), Hand Tapping, Behavioral Dyscontrol Scale (BDS), Controlled Oral Word Association Test (COWAT), and Fuld Object Memory Evaluation (FOME). The Global Deterioration Rating Scale (GDRS) was used to independently evaluate criterion-related validity for distinguishing cognitively normal and impaired groups. Relevant covariates included directly assessed functional status for basic and instrumental activities of daily living (DAFS), race, gender, educational attainment, Geriatric Depression Scale Short Form (GDS), and vision and hearing problems. RESULTS: Results suggest two distinct classes of cognitive performance in this centenarian sample. Approximately one third of the centenarians show a pattern of markedly lower cognitive performance on most measures. Group membership is independently well predicted (area under the curve [AUC] = .83) by GDRS scores (sensitivity 67.7%, specificity 82.4%). Membership in the lower cognitive performance group was more likely for individuals who were older, African Americans, had more depressive symptoms, lower plasma folate, carriers of the apolipoprotein E (APOE) ε4 allele, facility residents, and individuals who died in the 2 years following interview. CONCLUSIONS: In a population expected to have high prevalence of dementia, latent subtypes can be distinguished via factor mixture analysis that provide normative values for cognitive functioning. The present study allows estimates for normative cognitive performance in this age group.


Assuntos
Idoso de 80 Anos ou mais/psicologia , Cognição/classificação , Apolipoproteínas E/genética , Depressão/epidemiologia , Depressão/psicologia , Análise Fatorial , Feminino , Ácido Fólico/sangue , Georgia/epidemiologia , Avaliação Geriátrica , Humanos , Modelos Logísticos , Masculino , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica
16.
Heliyon ; 9(7): e17271, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37539228

RESUMO

In this study we assessed the neural correlates of functional vision while varying patterns of light filtration. Four filter conditions used relatively flat filtering across the visible spectrum while one filter was a step filter that selectively absorbed violet light (wavelengths below about 415 nm). Neural effects were quantified by measuring the BOLD response ((T2*-based fMRI) while subjects performed a challenging visual task (judging gap direction in Landolt Cs that randomly varied in size). In general (based on p < 0.01 directional criterion not corrected for aggregated error), as filtering increased (less interference by bright light), brain activity associated with the task also increased. This effect, even using the most conservative statistics, was most evident when using the violet filter (especially for the older subjects) despite only reducing the very highest energy portion of the visible spectrum. This finding suggests that filtering can increase neural activity associated with functional vision; such effects might be achievable through filtering just the highest visible energy (violet).

17.
Am J Sports Med ; 51(10): 2732-2739, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37462687

RESUMO

BACKGROUND: Current medical practices and recommendations largely ignore the safety of postconcussion driving, even though commonly used measures of neurocognition, balance, and vestibulo-ocular function show impairment. PURPOSE: To compare simulated driving between patients with concussion and controls throughout concussion recovery using a case-control design. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 26 concussed and 23 control Division I collegiate athletes completed a driving simulation assessment at 3 time points (within 72 hours, asymptomatic, and return to sport). Cumulative driving simulation outcome variables included total number of collisions, speed exceedances, stop signs missed, lane excursions, total drive time, percentage of time over the speed limit, and percentage of time out of the lane. The mean speed, standard deviation of speed (SDS), lateral lane position, and standard deviation of lateral lane position (SDLP) were examined for each of the 11 drive segments. Outcomes were compared using generalized linear mixed models with random intercepts by participant with Poisson or normal distributions. RESULTS: Within 72 hours of injury, the concussion group committed more lane excursions (median difference, 2; P = .003), exhibited greater SDS while avoiding a child pedestrian crossing the road (Cohen d = 0.73; P = .011), drove ~7 inches (~18 cm) closer to the centerline during a residential left curve (d = 0.90; P = .015), and had greater SDLP while navigating around a car crash compared with controls (d = 0.72; P = .016). When asymptomatic, the concussion group committed fewer speed exceedances (median difference, 2; P = .002) and had lower SDLP while navigating through a traffic light compared with controls (d = 0.60; P = .045). No differences were evident at return to sport. Groups did not differ in total collisions at any time point. CONCLUSION: The concussion group showed more impaired driving patterns within 72 hours of injury, drove more conservatively once asymptomatic, and had similar driving performance at the time they returned fully to sport. Clinicians should consider these findings when discussing driving with patients acutely after concussion. Further research is needed to determine whether on-road collision risk is elevated after concussion.


Assuntos
Traumatismos em Atletas , Concussão Encefálica , Esportes , Criança , Humanos , Estudos de Coortes , Concussão Encefálica/diagnóstico , Atletas , Traumatismos em Atletas/diagnóstico
18.
Neuroimage ; 59(2): 1382-93, 2012 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-21875672

RESUMO

Segregation and integration are two general principles of the brain's functional architecture. Therefore, brain network analysis is of significant importance in understanding brain function. Critical to brain network construction and analysis is the identification of reliable, reproducible, and accurate network nodes, or Regions of Interest (ROIs). Task-based fMRI has been widely considered as a reliable approach to identify functionally meaningful ROIs in the brain. However, recent studies have shown that factors such as spatial smoothing could considerably shift the locations of detected activation peaks. As a result, structural and functional connectivity patterns can be significantly altered. Here, we propose a novel framework by which to optimize ROI sizes and locations, ensuring that differences between the structural connectivity profiles among a group of subjects is minimized. This framework is based on functional ROIs derived from task-based fMRI and diffusion tensor imaging (DTI) data. Accordingly, we present a new approach to describe and measure the fiber bundle similarity quantitatively within and across subjects which will facilitate the optimization procedure. Experimental results demonstrated that this framework improved the localizations of fMRI-derived ROIs. Through our optimization procedure, structural and functional connectivities were more consistent across different individuals. Overall, the ability to accurately localize network ROIs could facilitate many applications in brain imaging that rely on the accurate identification of ROIs.


Assuntos
Algoritmos , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Interpretação de Imagem Assistida por Computador/métodos , Armazenamento e Recuperação da Informação/métodos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Automatizado de Padrão/métodos , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Neuroimage ; 61(1): 82-97, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22414991

RESUMO

Identification of regions of interest (ROIs) is a fundamental issue in brain network construction and analysis. Recent studies demonstrate that multimodal neuroimaging approaches and joint analysis strategies are crucial for accurate, reliable and individualized identification of brain ROIs. In this paper, we present a novel approach of visual analytics and its open-source software for ROI definition and brain network construction. By combining neuroscience knowledge and computational intelligence capabilities, visual analytics can generate accurate, reliable and individualized ROIs for brain networks via joint modeling of multimodal neuroimaging data and an intuitive and real-time visual analytics interface. Furthermore, it can be used as a functional ROI optimization and prediction solution when fMRI data is unavailable or inadequate. We have applied this approach to an operation span working memory fMRI/DTI dataset, a schizophrenia DTI/resting state fMRI (R-fMRI) dataset, and a mild cognitive impairment DTI/R-fMRI dataset, in order to demonstrate the effectiveness of visual analytics. Our experimental results are encouraging.


Assuntos
Mapeamento Encefálico/métodos , Processamento de Imagem Assistida por Computador/métodos , Rede Nervosa/anatomia & histologia , Idoso , Disfunção Cognitiva/patologia , Imagem de Tensor de Difusão , Feminino , Humanos , Conhecimento , Imageamento por Ressonância Magnética , Masculino , Memória de Curto Prazo/fisiologia , Rede Nervosa/patologia , Testes Neuropsicológicos , Neurociências , Reprodutibilidade dos Testes , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Software , Interface Usuário-Computador , Adulto Jovem
20.
Brain Inj ; 26(13-14): 1684-96, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23163249

RESUMO

INTRODUCTION: Mild traumatic brain injury (mTBI) or concussion has been acutely associated with several cognitive symptoms, including deficits in response inhibition, working memory and motor performance. The pervasiveness of these cognitive symptoms has been more controversial. The effects of multiple concussions on neuropsychological functioning and brain activation following at least 6-months post-mTBI were examined. METHODS: Twenty right-handed male athletes with a history of at least two concussions and 20 age/pre-morbid IQ/athletic-experience matched controls underwent neuropsychological assessment and fMRI scanning where they performed versions of a colour-word Stroop interference task, an operation-span working memory task and a finger-tapping task. RESULTS: The Attention index score on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was lower for the concussion group, but only at liberal statistical threshold. Total RBANS score approached statistical significance. Reaction time during neurobehavioural tasks was similar across groups, but accuracy was reduced in the concussed group on the working memory task. Despite expected activation patterns within each group, there were no group differences in neural activation on any functional tasks using either whole-brain or ROI-specific analyses at liberal statistical thresholds. CONCLUSION: There were minimal differences between the two closely matched groups. Results point to the relative plasticity of younger adults' cognitive abilities following concussion.


Assuntos
Traumatismos em Atletas/fisiopatologia , Concussão Encefálica/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Imageamento por Ressonância Magnética , Memória de Curto Prazo , Adolescente , Adulto , Traumatismos em Atletas/complicações , Traumatismos em Atletas/psicologia , Concussão Encefálica/complicações , Concussão Encefálica/etiologia , Concussão Encefálica/psicologia , Estudos de Casos e Controles , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Estudos Transversais , Humanos , Masculino , Plasticidade Neuronal , Testes Neuropsicológicos , Tempo de Reação , Reprodutibilidade dos Testes , Análise e Desempenho de Tarefas , Fatores de Tempo , Adulto Jovem
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