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1.
BMJ ; 374: n1743, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348957

RESUMO

OBJECTIVES: To examine multiple objective and self-reported measures of motor function for their associations with mortality. DESIGN: Prospective cohort study. SETTING: UK based Whitehall II cohort study, which recruited participants aged 35-55 years in 1985-88; motor function component was added at the 2007-09 wave. PARTICIPANTS: 6194 participants with motor function measures in 2007-09 (mean age 65.6, SD 5.9), 2012-13, and 2015-16. MAIN OUTCOME MEASURES: All cause mortality between 2007 and 2019 in relation to objective measures (walking speed, grip strength, and timed chair rises) and self-reported measures (physical component summary score of the SF-36 and limitations in basic and instrumental activities of daily living (ADL)) of motor function. RESULTS: One sex specific standard deviation poorer motor function in 2007-09 (cases/total, 610/5645) was associated with an increased mortality risk of 22% (95% confidence interval 12% to 33%) for walking speed, 15% (6% to 25%) for grip strength, 14% (7% to 23%) for timed chair rises, and 17% (8% to 26%) for physical component summary score over a mean 10.6 year follow-up. Having basic/instrumental ADL limitations was associated with a 30% (7% to 58%) increased mortality risk. These associations were progressively stronger when measures were drawn from 2012-13 (mean follow-up 6.8 years) and 2015-16 (mean follow-up 3.7 years). Analysis of trajectories showed poorer motor function in decedents (n=484) than survivors (n=6194) up to 10 years before death for timed chair rises (standardised difference 0.35, 95% confidence interval 0.12 to 0.59; equivalent to a 1.2 (men) and 1.3 (women) second difference), nine years for walking speed (0.21, 0.05 to 0.36; 5.5 (men) and 5.3 (women) cm/s difference), six years for grip strength (0.10, 0.01 to 0.20; 0.9 (men) and 0.6 (women) kg difference), seven years for physical component summary score (0.15, 0.05 to 0.25; 1.2 (men) and 1.6 (women) score difference), and four years for basic/instrumental ADL limitations (prevalence difference 2%, 0% to 4%). These differences increased in the period leading to death for timed chair rises, physical component summary score, and ADL limitations. CONCLUSION: Motor function in early old age has a robust association with mortality, with evidence of terminal decline emerging early in measures of overall motor function (timed chair rises and physical component summary score) and late in basic/instrumental ADL limitations.


Assuntos
Força da Mão/fisiologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Velocidade de Caminhada/fisiologia , Atividades Cotidianas , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autorrelato , Taxa de Sobrevida , Fatores de Tempo , Reino Unido
2.
Neurology ; 97(7): e706-e719, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34400568

RESUMO

OBJECTIVE: To determine similarities and differences in key predictors of recovery of bimanual hand use and unimanual motor impairment after stroke. METHOD: In this prospective longitudinal study, 89 patients with first-ever stroke with arm paresis were assessed at 3 weeks and 3 and 6 months after stroke onset. Bimanual activity performance was assessed with the Adult Assisting Hand Assessment Stroke (Ad-AHA), and unimanual motor impairment was assessed with the Fugl-Meyer Assessment (FMA). Candidate predictors included shoulder abduction and finger extension measured by the corresponding FMA items (FMA-SAFE; range 0-4) and sensory and cognitive impairment. MRI was used to measure weighted corticospinal tract lesion load (wCST-LL) and resting-state interhemispheric functional connectivity (FC). RESULTS: Initial Ad-AHA performance was poor but improved over time in all (mild-severe) impairment subgroups. Ad-AHA correlated with FMA at each time point (r > 0.88, p < 0.001), and recovery trajectories were similar. In patients with moderate to severe initial FMA, FMA-SAFE score was the strongest predictor of Ad-AHA outcome (R 2 = 0.81) and degree of recovery (R 2 = 0.64). Two-point discrimination explained additional variance in Ad-AHA outcome (R 2 = 0.05). Repeated analyses without FMA-SAFE score identified wCST-LL and cognitive impairment as additional predictors. A wCST-LL >5.5 cm3 strongly predicted low to minimal FMA/Ad-AHA recovery (≤10 and 20 points respectively, specificity = 0.91). FC explained some additional variance to FMA-SAFE score only in unimanual recovery. CONCLUSION: Although recovery of bimanual activity depends on the extent of corticospinal tract injury and initial sensory and cognitive impairments, FMA-SAFE score captures most of the variance explained by these mechanisms. FMA-SAFE score, a straightforward clinical measure, strongly predicts bimanual recovery. CLINICALTRIALSGOV IDENTIFIER: NCT02878304. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that the FMA-SAFE score predicts bimanual recovery after stroke.


Assuntos
Disfunção Cognitiva/fisiopatologia , Conectoma , Mãos/fisiopatologia , Avaliação de Resultados em Cuidados de Saúde , Paresia/fisiopatologia , Desempenho Psicomotor/fisiologia , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Paresia/diagnóstico , Paresia/etiologia , Prognóstico , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico
3.
Neurobiol Aging ; 106: 80-94, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34256190

RESUMO

Healthy aging is accompanied by reduced cognitive control and widespread alterations in the underlying brain networks; but the extent to which large-scale functional networks in older age show reduced specificity across different domains of cognitive control is unclear. Here we use cov-STATIS (a multi-table multivariate technique) to examine similarity of functional connectivity during different domains of cognitive control-inhibition, initiation, shifting, and working memory-across the adult lifespan. We report two major findings: (1) Functional connectivity patterns during initiation, inhibition, and shifting were more similar in older ages, particularly for control and default networks, a pattern consistent with dedifferentiation of the neural correlates associated with cognitive control; and (2) Networks exhibited age-related reconfiguration such that frontal, default, and dorsal attention networks were more integrated whereas sub-networks of somato-motor system were more segregated in older age. Together these findings offer new evidence for dedifferentiation and reconfiguration of functional connectivity underlying different aspects of cognitive control in normal aging.


Assuntos
Encéfalo/fisiologia , Desdiferenciação Celular/fisiologia , Cognição/fisiologia , Envelhecimento Saudável/fisiologia , Longevidade/fisiologia , Rede Nervosa/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Envelhecimento/psicologia , Encéfalo/diagnóstico por imagem , Feminino , Envelhecimento Saudável/psicologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Desempenho Psicomotor/fisiologia , Adulto Jovem
4.
Aging (Albany NY) ; 13(13): 17080-17096, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34232918

RESUMO

Emerging evidence suggests that olfactory function is closely linked to memory function. The aims of this study were to assess whether olfactory and episodic memory functions follow similar age-related decline trajectories, to identify different patterns of decline, as well as predictors of the patterns. 1023 participants from the Memory and Aging Project were followed for up to 8 years with annual episodic memory and odor identification assessments. Trajectories were modelled using growth mixture models. Multivariate logistic regression was used to identify pattern predictors. Three patterns of joint trajectories were identified; Class 1- stable average performance in both functions (n=690, 67.4%); Class 2- stable average episodic memory and declining odor identification (n=231, 22.6%); and Class 3- decline in both functions (n= 102, 10.0%). Class predictors included age, sex, APOE ε4 status, cognitive activity level and BMI. Participants in Class 3 were most likely to develop dementia. Episodic memory and olfactory function show similar trajectories in aging. Such classification can contribute to a better understanding of the factors related to cognitive decline and dementia.


Assuntos
Envelhecimento/fisiologia , Memória Episódica , Desempenho Psicomotor/fisiologia , Olfato/fisiologia , Idoso , Idoso de 80 Anos ou mais , Apolipoproteína E4/genética , Índice de Massa Corporal , Cognição/fisiologia , Disfunção Cognitiva , Escolaridade , Exercício Físico , Feminino , Humanos , Estudos Longitudinais , Masculino , Odorantes , Caracteres Sexuais , Comportamento Social , Classe Social
5.
Medicine (Baltimore) ; 100(24): e26275, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34128859

RESUMO

ABSTRACT: This study was conducted to investigate the effects of the degree of dual-task (DT) interference on gait, dual-task cost (DTC), cognitive ability, balance, and fall efficacy in people with stroke.In this cross-sectional study, people with chronic stroke (N = 36) performed a DT gait assessment (gait and cognitive task). During the evaluation, DT interference in motor and cognition was evaluated simultaneously. Thus, the group with severe interference in both tasks (mutual interference) was compared with the group with mild interference in either.The main effects for the degree of motor interference were observed on gait performance, DTC in motor, time up and go, and trail-making test B. In the cognitive interference, the main effects were observed on correct response rate, DTC in cognition, time up and go, and trail-making test B. An interaction effect was observed in the trail-making test B.The degree of motor interference affected gait, balance ability, and executive function (EF), and the degree of cognitive interference influenced the correct response rate in the DT condition, balance ability, and EF. Furthermore, mutual interference led to a significant reduction in EF in people with stroke.


Assuntos
Cognição/fisiologia , Marcha/fisiologia , Equilíbrio Postural/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/psicologia , Acidentes por Quedas , Idoso , Estudos Transversais , Avaliação da Deficiência , Feminino , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor/fisiologia , Reabilitação do Acidente Vascular Cerebral , Análise e Desempenho de Tarefas
6.
Commun Biol ; 4(1): 816, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34188170

RESUMO

It is often necessary for individuals to coordinate their actions with others. In the real world, joint actions rely on the direct observation of co-actors and rhythmic cues. But how are joint actions coordinated when such cues are unavailable? To address this question, we recorded brain activity while pairs of participants guided a cursor to a target either individually (solo control) or together with a partner (joint control) from whom they were physically and visibly separated. Behavioural patterns revealed that joint action involved real-time coordination between co-actors and improved accuracy for the lower performing co-actor. Concurrent neural recordings and eye tracking revealed that joint control affected cognitive processing across multiple stages. Joint control involved increases in both behavioural and neural coupling - both quantified as interpersonal correlations - peaking at action completion. Correspondingly, a neural offset response acted as a mechanism for and marker of interpersonal neural coupling, underpinning successful joint actions.


Assuntos
Encéfalo/fisiologia , Comportamento Cooperativo , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Cognição/fisiologia , Sinais (Psicologia) , Potenciais Evocados , Feminino , Humanos , Masculino , Adulto Jovem
7.
Neuron ; 109(13): 2183-2201.e9, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34077741

RESUMO

The neuronal mechanisms generating a delayed motor response initiated by a sensory cue remain elusive. Here, we tracked the precise sequence of cortical activity in mice transforming a brief whisker stimulus into delayed licking using wide-field calcium imaging, multiregion high-density electrophysiology, and time-resolved optogenetic manipulation. Rapid activity evoked by whisker deflection acquired two prominent features for task performance: (1) an enhanced excitation of secondary whisker motor cortex, suggesting its important role connecting whisker sensory processing to lick motor planning; and (2) a transient reduction of activity in orofacial sensorimotor cortex, which contributed to suppressing premature licking. Subsequent widespread cortical activity during the delay period largely correlated with anticipatory movements, but when these were accounted for, a focal sustained activity remained in frontal cortex, which was causally essential for licking in the response period. Our results demonstrate key cortical nodes for motor plan generation and timely execution in delayed goal-directed licking.


Assuntos
Comportamento Animal , Neurônios/fisiologia , Desempenho Psicomotor/fisiologia , Córtex Sensório-Motor/fisiologia , Percepção do Tato/fisiologia , Animais , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Vias Neurais/fisiologia , Optogenética
8.
J Sports Sci ; 39(sup1): 62-72, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34092196

RESUMO

The current protocol for classifying Para swimmers with hypertonia, ataxia and athetosis involves a physical assessment where the individual's ability to coordinate their limbs is scored by subjective clinical judgment. The lack of objective measurement renders the current test unsuitable for evidence-based classification. This study evaluated a revised version of the Para swimming assessment for motor coordination, incorporating practical, objective measures of movement smoothness, rhythm error and accuracy. Nineteen Para athletes with hypertonia and 19 non-disabled participants performed 30 s trials of bilateral alternating shoulder flexion-extension at 30 bpm and 120 bpm. Accelerometry was used to quantify movement smoothness; rhythm error and accuracy were obtained from video. Para athletes presented significantly less smooth movement and higher rhythm error than the non-disabled participants (p < 0.05). Random forest algorithm successfully classified 89% of participants with hypertonia during out-of-bag predictions. The most important predictors in classifying participants were movement smoothness at both movement speeds, and rhythm error at 120 bpm. Our results suggest objective measures of movement smoothness and rhythm error included in the current motor coordination test protocols can be used to infer impairment in Para swimmers with hypertonia. Further research is merited to establish the relationship of these measures with swimming performance.


Assuntos
Paralisia Cerebral/fisiopatologia , Hipertonia Muscular/fisiopatologia , Desempenho Psicomotor/fisiologia , Esportes para Pessoas com Deficiência/fisiologia , Natação/fisiologia , Acelerometria , Adulto , Algoritmos , Ataxia/fisiopatologia , Atetose/fisiopatologia , Desempenho Atlético/fisiologia , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Masculino , Movimento/fisiologia , Hipertonia Muscular/classificação , Paratletas/classificação , Desempenho Físico Funcional , Amplitude de Movimento Articular/fisiologia , Ombro/fisiologia , Esportes para Pessoas com Deficiência/classificação , Natação/classificação , Gravação em Vídeo , Adulto Jovem
9.
J Sports Sci ; 39(sup1): 73-80, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34092197

RESUMO

This study examined the reliability of instrumented trunk assessment methods across two experiments to develop and improve evidence-based classification in Para swimming. Trunk coordination, range of motion (ROM), and strength were assessed in 38 non-disabled participants. Each test battery was completed on two occasions to determine inter-session reliability. Intra-session reliability was also determined in Experiment Two. Absolute agreement of two-way mixed intraclass correlation coefficients (ICC 3,1) was calculated to assess reliability. Standard errors of measurement (SEMs) were also reported to facilitate comparisons between different outcomes. Trunk coordination measures had low-to-moderate reliability (inter-session ICCs = 0.00-0.60; intra-session ICCs = 0.14-0.65) and variable SEMs (5-60%). Trunk ROM demonstrated moderate-to-excellent reliability (inter-session ICCs = 0.61-0.93; intra-session ICCs = 0.87-0.95) and good SEMs (<10%). Trunk strength measures demonstrated good-to-excellent reliability (ICCs = 0.87-0.98) and good SEMs (<10%). The strength values obtained for the load cell and hand-held dynamometer (HHD) were significantly different from each other with the HHD underestimating strength. Modifications provided in Experiment Two improved the reliability of strength and ROM assessments but did not improve coordination measures. Further research involving para swimmers is required to establish the validity of the methods.


Assuntos
Força Muscular/fisiologia , Desempenho Psicomotor/fisiologia , Amplitude de Movimento Articular/fisiologia , Natação/fisiologia , Tronco/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Voluntários Saudáveis , Humanos , Dinamômetro de Força Muscular , Paratletas/classificação , Reprodutibilidade dos Testes , Postura Sentada , Coluna Vertebral , Esportes para Pessoas com Deficiência/classificação , Esportes para Pessoas com Deficiência/fisiologia , Natação/classificação , Adulto Jovem
10.
Commun Biol ; 4(1): 719, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34117346

RESUMO

Decision making is a cognitive process that mediates behaviors critical for survival. Choosing spatial targets is an experimentally-tractable form of decision making that depends on the midbrain superior colliculus (SC). While physiological and computational studies have uncovered the functional topographic organization of the SC, the role of specific SC cell types in spatial choice is unknown. Here, we leveraged behavior, optogenetics, neural recordings and modeling to directly examine the contribution of GABAergic SC neurons to the selection of opposing spatial targets. Although GABAergic SC neurons comprise a heterogeneous population with local and long-range projections, our results demonstrate that GABAergic SC neurons do not locally suppress premotor output, suggesting that functional long-range inhibition instead plays a dominant role in spatial choice. An attractor model requiring only intrinsic SC circuitry was sufficient to account for our experimental observations. Overall, our study elucidates the role of GABAergic SC neurons in spatial choice.


Assuntos
Neurônios GABAérgicos/fisiologia , Desempenho Psicomotor/fisiologia , Colículos Superiores/fisiologia , Animais , Comportamento de Escolha/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Optogenética , Navegação Espacial/fisiologia , Colículos Superiores/citologia
11.
Nat Commun ; 12(1): 3373, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099727

RESUMO

Theta rhythms temporally coordinate sequences of hippocampal place cell ensembles during active behaviors, while sharp wave-ripples coordinate place cell sequences during rest. We investigated whether such coordination of hippocampal place cell sequences is disrupted during error trials in a delayed match-to-place task. As a reward location was learned across trials, place cell sequences developed that represented temporally compressed paths to the reward location during the approach to the reward location. Less compressed paths were represented on error trials as an incorrect stop location was approached. During rest periods of correct but not error trials, place cell sequences developed a bias to replay representations of paths ending at the correct reward location. These results support the hypothesis that coordination of place cell sequences by theta rhythms and sharp wave-ripples develops as a reward location is learned and may be important for the successful performance of a spatial memory task.


Assuntos
Hipocampo/fisiologia , Células de Lugar/fisiologia , Desempenho Psicomotor/fisiologia , Memória Espacial/fisiologia , Ritmo Teta/fisiologia , Algoritmos , Animais , Teorema de Bayes , Hipocampo/citologia , Aprendizagem/fisiologia , Masculino , Ratos Long-Evans , Recompensa
12.
Nat Commun ; 12(1): 3823, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158482

RESUMO

Adolescents are prone to social influence from peers, with implications for development, both adaptive and maladaptive. Here, using a computer-based paradigm, we replicate a cross-sectional effect of more susceptibility to peer influence in a large dataset of adolescents 14 to 24 years old. Crucially, we extend this finding by adopting a longitudinal perspective, showing that a within-person susceptibility to social influence decreases over a 1.5 year follow-up time period. Exploiting this longitudinal design, we show that susceptibility to social influences at baseline predicts an improvement in peer relations over the follow-up period. Using a Bayesian computational model, we demonstrate that in younger adolescents a greater tendency to adopt others' preferences arises out of a higher uncertainty about their own preferences in the paradigmatic case of delay discounting (a phenomenon called 'preference uncertainty'). This preference uncertainty decreases over time and, in turn, leads to a reduced susceptibility of one's own behaviour to an influence from others. Neuro-developmentally, we show that a measure of myelination within medial prefrontal cortex, estimated at baseline, predicts a developmental decrease in preference uncertainty at follow-up. Thus, using computational and neural evidence, we reveal adaptive mechanisms underpinning susceptibility to social influence during adolescence.


Assuntos
Comportamento do Adolescente/fisiologia , Infuência dos Pares , Comportamento Social , Incerteza , Adolescente , Desenvolvimento do Adolescente , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Grupo Associado , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Adulto Jovem
13.
Nature ; 594(7861): 82-87, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34012117

RESUMO

Precise tongue control is necessary for drinking, eating and vocalizing1-3. However, because tongue movements are fast and difficult to resolve, neural control of lingual kinematics remains poorly understood. Here we combine kilohertz-frame-rate imaging and a deep-learning-based neural network to resolve 3D tongue kinematics in mice drinking from a water spout. Successful licks required corrective submovements that-similar to online corrections during primate reaches4-11-occurred after the tongue missed unseen, distant or displaced targets. Photoinhibition of anterolateral motor cortex impaired corrections, which resulted in hypometric licks that missed the spout. Neural activity in anterolateral motor cortex reflected upcoming, ongoing and past corrective submovements, as well as errors in predicted spout contact. Although less than a tenth of a second in duration, a single mouse lick exhibits the hallmarks of online motor control associated with a primate reach, including cortex-dependent corrections after misses.


Assuntos
Adaptação Fisiológica , Atenção , Ingestão de Líquidos , Córtex Motor/fisiologia , Desempenho Psicomotor/fisiologia , Língua/fisiologia , Animais , Fenômenos Biomecânicos , Aprendizado Profundo , Masculino , Camundongos , Tempo de Reação , Água
14.
Arch Dis Child ; 106(9): 834-838, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34035035

RESUMO

As survival rates for children born extremely preterm (EP, <28 weeks' gestation) have increased with advances in perinatal and neonatal care, their long-term functioning and quality of life assume more importance. Outcomes in early childhood provide some information, but outcomes at school-age are more informative of life-long functioning. Children born EP at school-age have substantially higher rates of intellectual impairment, poorer executive, academic and motor function, more neurodevelopmental disability, and poorer health-related quality of life than do contemporaneous term-born controls. Because the rates of adverse outcomes remain unacceptably high, and particularly since some outcomes may be deteriorating rather than improving over time, new strategies to ameliorate these problems, targeting periods before, during and after birth, and throughout the lifespan, are a priority.


Assuntos
Lactente Extremamente Prematuro/psicologia , Deficiência Intelectual/epidemiologia , Transtornos do Neurodesenvolvimento/epidemiologia , Instituições Acadêmicas/estatística & dados numéricos , Sucesso Acadêmico , Estudos de Casos e Controles , Criança , Pré-Escolar , Função Executiva/fisiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Desempenho Psicomotor/fisiologia , Qualidade de Vida , Instituições Acadêmicas/tendências , Taxa de Sobrevida
15.
PLoS Comput Biol ; 17(5): e1008594, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34010288

RESUMO

The central nervous system of humans and other animals modulates spinal cord activity to achieve several locomotion behaviors. Previous neuromechanical models investigated the modulation of human gait changing selected parameters belonging to CPGs (Central Pattern Generators) feedforward oscillatory structures or to feedback reflex circuits. CPG-based models could replicate slow and fast walking by changing only the oscillation's properties. On the other hand, reflex-based models could achieve different behaviors through optimizations of large dimensional parameter spaces. However, they could not effectively identify individual key reflex parameters responsible for gait characteristics' modulation. This study investigates which reflex parameters modulate the gait characteristics through neuromechanical simulations. A recently developed reflex-based model is used to perform optimizations with different target behaviors on speed, step length, and step duration to analyze the correlation between reflex parameters and their influence on these gait characteristics. We identified nine key parameters that may affect the target speed ranging from slow to fast walking (0.48 and 1.71 m/s) as well as a large range of step lengths (0.43 and 0.88 m) and step duration (0.51, 0.98 s). The findings show that specific reflexes during stance significantly affect step length regulation, mainly given by positive force feedback of the ankle plantarflexors' group. On the other hand, stretch reflexes active during swing of iliopsoas and gluteus maximus regulate all the gait characteristics under analysis. Additionally, the results show that the hamstrings' group's stretch reflex during the landing phase is responsible for modulating the step length and step duration. Additional validation studies in simulations demonstrated that the modulation of identified reflexes is sufficient to regulate the investigated gait characteristics. Thus, this study provides an overview of possible reflexes involved in modulating speed, step length, and step duration of human gaits.


Assuntos
Marcha/fisiologia , Locomoção/fisiologia , Modelos Neurológicos , Fenômenos Biomecânicos , Biologia Computacional , Simulação por Computador , Humanos , Modelos Anatômicos , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Sistema Musculoesquelético/anatomia & histologia , Sistema Musculoesquelético/inervação , Desempenho Psicomotor/fisiologia , Reflexo de Estiramento/fisiologia , Caminhada/fisiologia
16.
World Neurosurg ; 151: 182-189, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34033950

RESUMO

OBJECTIVE: Metric-based surgical training can be used to quantify the level and progression of neurosurgical performance to optimize and monitor training progress. Here we applied innovative metrics to a physical neurosurgery trainer to explore whether these metrics differentiate between different levels of experience across different tasks. METHODS: Twenty-four participants (9 experts, 15 novices) performed 4 tasks (dissection, spatial adaptation, depth adaptation, and the A-B-A task) using the PsT1 training system. Four performance metrics (collision, precision, dissected area, and time) and 6 kinematic metrics (dispersion, path length, depth perception, velocity, acceleration, and motion smoothness) were collected. RESULTS: For all tasks, the execution time (t) of the experts was significantly lower than that of novices (P < 0.05). The experts performed significantly better in all but 2 of the other metrics, dispersion and sectional area, corresponding to the A-B-A task and dissection task, respectively, for which they showed a nonsignificant trend towards better performance (P = 0.052 and P = 0.076, respectively). CONCLUSIONS: It is possible to differentiate between the skill levels of novices and experts according to parameters derived from the PsT1 platform, paving the way for the quantitative assessment of training progress using this system. During the current coronavirus disease 2019 pandemic, neurosurgical simulators that gather surgical performance metrics offer a solution to the educational needs of residents.


Assuntos
Competência Clínica , Neuroendoscopia/educação , Neuroendoscopia/métodos , Desempenho Psicomotor/fisiologia , Treinamento por Simulação/métodos , Competência Clínica/normas , Humanos , Neuroendoscopia/normas , Treinamento por Simulação/normas
17.
Neuropsychology ; 35(3): 310-322, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33970664

RESUMO

Objective: Right brain-damaged patients may show omissions and/or additional marks in target cancellation. The latter is classified as perseverative behavior and has been attributed to defective response inhibition or attentional disengagement deficit. This study aimed at (a) verifying that consecutive (immediate) and return (temporally distant) motor perseverations could be due to different mechanisms; (b) investigating the relationships among different types of perseveration (e.g., consecutive, return, scribble), spatial neglect and the impairment in specific components of executive functioning. Method: Seventeen right brain-damaged patients underwent letter, star, bell, and apple cancellation tasks. A global index for each type of perseveration found and Mean Position of Hits, as a neglect index, were calculated. The following components of executive functioning were evaluated: motor programming (Frontal Assessment Battery [FAB] subtest), inhibitory control FAB, interference sensitivity (FAB and Stroop color-word interference test), set-shifting (Weigl sorting test, Phonemic/semantic alternate fluencies), and working memory (Backward Digit span). Results: Ten patients out of 17 showed some degree of perseveration. Regularized linear regression analyses demonstrated that interference sensitivity and Stroop test performances were related to return perseverations and backward digit to scribble ones. No significant relationships were found for consecutive perseverations and between neglect and any type of perseverations. Conclusions: The present study showed that return perseverations might have a distinct etiology from consecutive ones, being related to an inability to update and shift between action programs according to the visual stimuli. A finer classification of perseverations could help in unveiling the neuropsychological mechanisms underlying each type of behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Lesões Encefálicas/fisiopatologia , Lateralidade Funcional , Transtornos da Percepção/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/psicologia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/psicologia , Neoplasias Encefálicas/fisiopatologia , Neoplasias Encefálicas/psicologia , Córtex Cerebral , Função Executiva , Feminino , Humanos , Hemorragias Intracranianas/fisiopatologia , Hemorragias Intracranianas/psicologia , Masculino , Memória de Curto Prazo , Pessoa de Meia-Idade , Testes Neuropsicológicos , Transtornos da Percepção/psicologia , Estudos Prospectivos , Desempenho Psicomotor/fisiologia , Teste de Stroop
18.
Nat Commun ; 12(1): 3112, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34035303

RESUMO

Sleep is thought to support memory consolidation via reactivation of prior experiences, with particular electrophysiological sleep signatures (slow oscillations (SOs) and sleep spindles) gating the information flow between relevant brain areas. However, empirical evidence for a role of endogenous memory reactivation (i.e., without experimentally delivered memory cues) for consolidation in humans is lacking. Here, we devised a paradigm in which participants acquired associative memories before taking a nap. Multivariate decoding was then used to capture endogenous memory reactivation during non-rapid eye movement (NREM) sleep in surface EEG recordings. Our results reveal reactivation of learning material during SO-spindle complexes, with the precision of SO-spindle coupling predicting reactivation strength. Critically, reactivation strength (i.e. classifier evidence in favor of the previously studied stimulus category) in turn predicts the level of consolidation across participants. These results elucidate the memory function of sleep in humans and emphasize the importance of SOs and spindles in clocking endogenous consolidation processes.


Assuntos
Encéfalo/fisiologia , Aprendizagem/fisiologia , Consolidação da Memória/fisiologia , Memória/fisiologia , Sono/fisiologia , Sinais (Psicologia) , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Estimulação Luminosa , Polissonografia/métodos , Desempenho Psicomotor/fisiologia , Adulto Jovem
19.
Nat Commun ; 12(1): 2514, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947840

RESUMO

Primates use their arms in complex ways that frequently require coordination between the two arms. Yet the planning of bimanual movements has not been well-studied. We recorded spikes and local field potentials (LFP) from the parietal reach region (PRR) in both hemispheres simultaneously while monkeys planned and executed unimanual and bimanual reaches. From analyses of interhemispheric LFP-LFP and spike-LFP coherence, we found that task-specific information is shared across hemispheres in a frequency-specific manner. This shared information could arise from common input or from direct communication. The population average unit activity in PRR, representing PRR output, encodes only planned contralateral arm movements while beta-band LFP power, a putative PRR input, reflects the pattern of planned bimanual movement. A parsimonious interpretation of these data is that PRR integrates information about the movement of the left and right limbs, perhaps in service of bimanual coordination.


Assuntos
Potenciais de Ação/fisiologia , Movimento/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Escala de Avaliação Comportamental , Eletrofisiologia , Lateralidade Funcional/fisiologia , Macaca mulatta , Masculino , Córtex Motor/fisiologia , Neurônios/fisiologia , Movimentos Sacádicos/fisiologia , Transdução de Sinais/fisiologia
20.
Cogn Res Princ Implic ; 6(1): 41, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34046743

RESUMO

The novel coronavirus disease 2019 (COVID-19) has considerably heightened health and financial concerns for many individuals. Similar concerns, such as those associated with poverty, impair performance on cognitive control tasks. If ongoing concerns about COVID-19 substantially increase the tendency to mind wander in tasks requiring sustained attention, these worries could degrade performance on a wide range of tasks, leading, for example, to increased traffic accidents, diminished educational achievement, and lower workplace productivity. In two pre-registered experiments, we investigated the degree to which young adults' concerns about COVID-19 correlated with their ability to sustain attention. Experiment 1 tested mainly European participants during an early phase of the pandemic. After completing a survey probing COVID-related concerns, participants engaged in a continuous performance task (CPT) over two, 4-min blocks, during which they responded to city scenes that occurred 90% of the time and withheld responses to mountain scenes that occurred 10% of the time. Despite large and stable individual differences, performance on the scene CPT did not significantly correlate with the severity of COVID-related concerns obtained from the survey. Experiment 2 tested US participants during a later phase of the pandemic. Once again, CPT performance did not significantly correlate with COVID concerns expressed in a pre-task survey. However, participants who had more task-unrelated thoughts performed more poorly on the CPT. These findings suggest that although COVID-19 increased anxiety in a broad swath of society, young adults are able to hold these concerns in a latent format, minimizing their impact on performance in a demanding sustained attention task.


Assuntos
Ansiedade/etiologia , Ansiedade/fisiopatologia , Atenção/fisiologia , COVID-19 , Reconhecimento Visual de Modelos/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Europa (Continente) , Feminino , Humanos , Masculino , Estados Unidos , Adulto Jovem
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