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1.
Sports Biomech ; 19(2): 271-279, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29671697

RESUMO

Numerous studies have investigated anterior cruciate ligament (ACL) injury risk by examining gender differences in knee and hip biomechanics during a side-step cutting manoeuvre since it is known that ACL injury often occurs during such a task. Recent investigations have also examined lower extremity (LE) biomechanics during side-step cutting in individuals following ACL reconstruction (ACLR). Common research practice is to compare knee and hip biomechanics of the dominant limb between groups but this can add considerable complexity for clinicians and researchers. At this time, it is not known if there is a difference in LE biomechanics between the dominant and non-dominant limb during side-step cutting. Three-dimensional kinematics and kinetics were collected while 31 healthy participants performed five, side-step cutting manoeuvres with the dominant and non-dominant limbs. Knee and hip variables examined are those commonly investigated in ACL injury literature. There were no differences between limbs in all but one variable (knee internal rotation). These results demonstrate that healthy individuals exhibit little side-to-side differences in certain LE biomechanics when performing a side-step cutting manoeuvre. These findings can be utilised by clinicians when conducting dynamic evaluations of their ACLR patients and when developing injury prevention and rehabilitation programmes.


Assuntos
Lateralidade Funcional/fisiologia , Extremidade Inferior/fisiologia , Destreza Motora/fisiologia , Adolescente , Adulto , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Fenômenos Biomecânicos , Feminino , Quadril/fisiologia , Humanos , Cinética , Joelho/fisiologia , Masculino , Fatores de Risco , Rotação , Estudos de Tempo e Movimento , Adulto Jovem
2.
BMC Neurol ; 19(1): 279, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718589

RESUMO

BACKGROUND: Cerebral infarction occurs when the arteries to brain are obstructed, and motor impairment contralateral to responsible lesion is commonly recognized. Few studies have profiled the characteristics of cases with ipsilateral motor impairment. We sought to characterize clinical features of patients with motor dysfunction caused by ipsilateral ischemic stroke. METHODS: We retrieved and analyzed the medical data for patients with ipsilateral cerebral infarction. Patients were regarded as having ipsilateral cerebral infarction if motor impairment is ipsilateral to recent stroke lesions. RESULTS: Only 22 patients with unusual ipsilateral cerebral infarction were included in this study. Ipsilateral limb paralysis was observed in all cases, and one case showed central facioplegia. Majority of patients with limb paralysis (90.9%, 20/22) presented with mild muscle strength deficits (MRC grading of 4 or more). Most of the patients (72.7%, 16/22) had a past history of stroke, and previous strokes were contralateral to the side of the recent stroke in 14 out of 16 patients (87.5%). No history of stroke or cerebral injury was identified in seven patients. With aspect of MRI findings, recent infarct lesions of all cases were located along the corticospinal tract. CONCLUSIONS: History of stroke plays an important role in the pathogenesis of ipsilateral motor impairment, and cortical reorganization in the unaffected hemisphere may contribute to the compensation of motor function after stroke. Besides that, some cases with first stroke may be due to impairment of ipsilateral uncrossed corticospinal fibers.


Assuntos
Infarto Cerebral/complicações , Infarto Cerebral/patologia , Lateralidade Funcional/fisiologia , Paralisia/etiologia , Paralisia/fisiopatologia , Adulto , Idoso , Infarto Cerebral/diagnóstico por imagem , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtornos Motores/etiologia , Transtornos Motores/fisiopatologia , Neuroimagem , Paralisia/diagnóstico por imagem , Acidente Vascular Cerebral/complicações
3.
Handb Clin Neurol ; 163: 179-196, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31590729

RESUMO

With the exception of language, hemispheric asymmetry has not historically been an important issue in the frontal lobe literature. Data generated over the past 20 years is forcing a reconsideration of this position. There is now considerable evidence to suggest that the left prefrontal cortex is an inference engine that automatically makes simple conceptual, logical, and causal connections to fill in missing information and eliminate uncertainty or indeterminacy. This is a fine-tuning of the "left hemisphere interpreter" account from the callosotomy patient literature. What is new is an understanding of the important contributions of the right prefrontal cortex to formal logical inference, conflict detection, and indeterminacy tolerance and maintenance. This chapter articulates these claims and reviews the data on which they are based. The chapter concludes by speculating that the inference capabilities of the left prefrontal cortex are built into the very fabric of language and can be accounted for by the left hemisphere dominance for language. The roles of the right PFC require multiple mechanisms for explanation. Its role in formal inference may be a function of its visual-spatial processing capabilities. Its role in conflict detection may be explained as a system for checking for consistency between existing beliefs and new information coming into the system and inferences drawn from beliefs and/or new information. There are at least three possible mechanisms to account for its role in indeterminacy tolerance. First, it could contain a representational system with properties very different from those of language, and an accompanying inference engine. Second, it could just contain this different representational system, and the information is at some point passed back to the left prefrontal cortex for inference. Third, the role of the right prefrontal cortex may be largely preventative. That is, it doesn't provide alternative representational and inference capabilities but simply prevents the left prefrontal cortex from settling on initial, local inferences. The current data do not allow differentiating between these possibilities. Successful real-world functioning requires the participation of both hemispheres.


Assuntos
Cognição/fisiologia , Lateralidade Funcional/fisiologia , Linguagem , Córtex Pré-Frontal/fisiologia , Tomada de Decisões/fisiologia , Humanos , Testes Neuropsicológicos
4.
Handb Clin Neurol ; 163: 221-235, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31590732

RESUMO

Recent research has demonstrated that the lateral prefrontal cortex is extensively involved in human memory, including working memory processes that support retention of information across short delays, and episodic long-term memory encoding and retrieval processes. This chapter reviews results from neuroimaging studies of memory, from noninvasive brain stimulation studies of memory, and from studies of memory in patients with prefrontal lesions. The available evidence is consistent with the idea that different prefrontal regions implement cognitive or executive control processes that support working memory and episodic long-term memory encoding and retrieval.


Assuntos
Lateralidade Funcional/fisiologia , Memória de Longo Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Mapeamento Encefálico , Estimulação Elétrica , Humanos , Neuroimagem , Testes Neuropsicológicos
6.
Exp Psychol ; 66(4): 310-317, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31530249

RESUMO

This work aimed to assess the role of manual laterality in action coding strategies and, subsequently, in environmental features relevant for each hand's action. Relying on Eder and Hommel's (2013) proposal, we distinguished stimulus-related and end state-related consequences in a Simon paradigm where right-handed participants were divided into two groups, one responding with gloves and one without. Two objects were presented pictorially: one for which sensory consequences of grasping were negatively valenced (a chestnut burr), and one for which they were positively valenced (an apricot). By these means, stimulus and end-state effects could be assessed separately, along with the relevance of each feature of the experimental settings. Results showed that the use of one's dominant or non dominant hand gives rise to different repercussions of stimulus-related and end state-related effects on response: Responses made with the right (dominant) hand were based on an elaborated coding (representing features of stimulus-related and end state-related consequences of action). In contrast, responses made with the left (non dominant) hand seemed to be based on a less elaborated coding (not taking into account end-state consequences of an action).


Assuntos
Lateralidade Funcional/fisiologia , Força da Mão/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Humanos , Masculino
7.
Dev Cogn Neurosci ; 39: 100704, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31476670

RESUMO

The humans' brain asymmetry is observed in the early stages of life and known to change further with age. The developmental trajectory of such an asymmetry has been observed for language, as one of the most lateralized cognitive functions. However, it remains unclear how these age-related changes in structural asymmetry are related to changes in language performance. We collected longitudinal structural magnetic resonance imaging data of children from 5 to 6 years to investigate structural asymmetry development and its linkage to the improvement of language comprehension abilities. Our results showed substantial changes of language performance across time, which were associated with changes of cortical thickness asymmetry in the triangular part of the inferior frontal gyrus (IFG), constituting a portion of Broca's area. This suggests that language improvement is influenced by larger cortical thinning in the left triangular IFG compared to the right. This asymmetry in children's brain at age 5 and 6 years was further associated with the language performance at 7 years. To our knowledge, this is the first longitudinal study to demonstrate that children's improvement in sentence comprehension seems to depend on structural asymmetry changes in the IFG, further highlighting its crucial role in language acquisition.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Lateralidade Funcional/fisiologia , Desenvolvimento da Linguagem , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Masculino , Tamanho do Órgão
8.
Psychol Addict Behav ; 33(7): 626-636, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31497986

RESUMO

Exerting self-control depletes capacity for future self-control, which can promote greater alcohol use. However, certain populations may be more susceptible to these effects of depleted self-control capacity. For example, individuals with lower alcohol sensitivity (i.e., requiring more drinks to experience the effects of alcohol) are a high-risk group who are likely to engage in hazardous alcohol use and develop an alcohol use disorder. Those lower in alcohol sensitivity also exhibit heightened motivational reactivity in response to alcohol-related cues, which may be enhanced following exertion of self-control. However, whether drinkers lower in alcohol sensitivity are at higher risk for exhibiting greater motivations toward alcohol-related cues after exerting self-control is unclear. The current research examined the role of alcohol sensitivity in predicting approach motivation following exertion of self-control. It was expected drinkers exerting self-control would exhibit greater orientation toward rewarding cues, particularly after viewing alcohol-related cues. However, we predicted this pattern would be most prominent among drinkers lower in alcohol sensitivity. Experiment 1 supported these hypotheses, with lower alcohol sensitivity predicting greater approach motivation among drinkers required to exert self-control prior to viewing alcohol-related compared to neutral cues. Experiment 2 aimed to replicate these findings by assessing asymmetrical frontal cortical activation, an index of approach motivation. Drinkers with lower alcohol sensitivity exhibited greater relative left frontal cortical activation, consistent with approach motivation, while viewing alcohol-related cues following exertion of self-control. Results have implications for interventions aimed at identifying those at risk for greater alcohol motivations during states of mental exhaustion. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Consumo de Bebidas Alcoólicas/fisiopatologia , Depressores do Sistema Nervoso Central/farmacologia , Sinais (Psicologia) , Etanol/farmacologia , Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Motivação/fisiologia , Autocontrole , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
9.
Rev. neurol. (Ed. impr.) ; 69(5): 190-198, 1 sept., 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-184456

RESUMO

Introducción. Habitualmente, el paciente con heminegligencia visuoespacial secundaria a un ictus no es consciente de que su percepción y exploración del espacio contralesional son defectuosas. Este fenómeno clínico, conocido como anosognosia, condiciona directamente el proceso rehabilitador y amplía sensiblemente su duración, al tiempo que dificulta la adhesión del paciente a dicho proceso. Objetivo. Valorar la eficacia de un programa de rehabilitación específico para el tratamiento de la anosognosia en pacientes que presentan heminegligencia visuoespacial. Pacientes y métodos. Se distribuyó a 12 pacientes con ictus hemisférico derecho en dos grupos. El grupo experimental recibió 15 sesiones de tratamiento cognitivo informatizado junto con 15 sesiones de rehabilitación específicas para la anosognosia. El grupo control realizó 15 sesiones de tratamiento cognitivo informatizado. A todos ellos se les administró, antes y después del tratamiento, una batería de test para evaluar la atención visuoespacial. El nivel de funcionalidad se valoró mediante la Catherine Bergego Scale. Resultados. Tras la intervención, el grupo control mostró diferencias psicométricas estadísticamente significativas. No sucedió lo mismo con el grupo experimental. No se obtuvieron diferencias en las comparaciones intergrupales pre y postratamiento, ni en las medidas psicométricas ni en la escala funcional. Conclusiones. Es necesario seguir realizando investigaciones que nos ayuden a mejorar el tratamiento de la anosognosia en pacientes que presentan heminegligencia visuoespacial. Se plantean algunas recomendaciones metodológicas surgidas de las limitaciones identificadas en el presente estudio


Introduction. Patients with unilateral visuospatial neglect secondary to a stroke are usually unaware of the fact that their perception and exploration of contralesional space are deficient. This clinical phenomenon, know as anosognosia, directly conditions the rehabilitation process and prolongs its duration to a significant extent, while also making it more difficult for the patient to adhere to it. Aim. To assess the efficacy of a specific rehabilitation programme for the treatment of anosognosia in patients presenting with unilateral visuospatial neglect. Patients and methods. Twelve patients with a stroke in the right hemisphere were divided into two groups. The experimental group received 15 sessions of computerised cognitive therapy along with 15 sessions of specific rehabilitation for anosognosia. The control group underwent 15 sessions of computerised cognitive treatment. All of them were administered, before and after treatment, a battery of tests to evaluate visuospatial attention. The level of functionality was evaluated by means of the Catherine Bergego Scale. Results. After the intervention, the control group showed statistically significant psychometric differences. The same did not occur with the experimental group. No differences were obtained in the pre- and post-treatment intergroup comparisons, or in the psychometric measures or on the functional scale. Conclusions. Further research is needed to help us improve the treatment of anosognosia in patients with unilateral visuospatial neglect. Some methodological recommendations emerge from the limitations identified in this study


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Agnosia/reabilitação , Agnosia/etiologia , Agnosia/fisiopatologia , Lateralidade Funcional/fisiologia , Estudos de Casos e Controles , Resultado do Tratamento , Escolaridade , Fatores de Tempo
10.
Medicina (Kaunas) ; 55(8)2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31390821

RESUMO

Background and Objective: The objective of this study was to evaluate the potential independent and interactive effects of handedness and grip strength on episodic memory function, and whether biological sex moderated these relationships. Materials and Methods: 162 young adults (Mage = 20.7 years) completed a series of memory assessments including a subjective memory complaint evaluation and several objective measures of memory. Handedness (i.e., left-hand dominant, inconsistent handedness (ICH), and right-hand dominant) was evaluated using the Edinburgh Handedness Inventory. Handgrip strength was determined from a handgrip dynamometer. Results: When compared to ICH individuals, retrospective memory scores were statistically significantly worse for left-handed (p = 0.02) and right-handed (p = 0.03) individuals. Higher grip strength was statistically significantly associated with fewer retrospective memory complaints (b = 0.10, 95% CI: 0.01, 0.19, p = 0.04). Conclusions: The present study provides some suggestive evidence that ICH (inconsistent handedness) and greater grip strength are associated with fewer retrospective memory complaints. However, we did not observe any evidence of an interaction effect of handedness and grip strength on memory, and similarly, biological sex did not interact with these parameters to influence memory.


Assuntos
Lateralidade Funcional/fisiologia , Força da Mão/fisiologia , Memória/fisiologia , Fatores Sexuais , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência/estatística & dados numéricos , Mississippi , Inquéritos e Questionários , Adulto Jovem
11.
Laterality ; 24(6): 707-739, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31399020

RESUMO

Several non-verbal perceptual and attentional processes have been linked with specialization of the right cerebral hemisphere. Given that most people have a left hemispheric specialization for language, it is tempting to assume that functions of these two classes of dominance are related. Unfortunately, such models of complementarity are notoriously hard to test. Here we suggest a method which compares frequency of a particular perceptual asymmetry with known frequencies of left hemispheric language dominance in right-handed and non-right handed groups. We illustrate this idea using the greyscales and colourscales tasks, chimeric faces, emotional dichotic listening, and a consonant-vowel dichotic listening task. Results show a substantial "breadth" of leftward bias on the right hemispheric tasks and rightward bias on verbal dichotic listening. Right handers and non-right handers did not differ in terms of proportions of people who were left biased for greyscales/colourscales. Support for reduced typical biases in non-right handers was found for chimeric faces and for CV dichotic listening. Results are discussed in terms of complementary theories of cerebral asymmetries, and how this type of method could be used to create a taxonomy of lateralized functions, each categorized as related to speech and language dominance, or not.


Assuntos
Dominância Cerebral/fisiologia , Lateralidade Funcional/fisiologia , Percepção/fisiologia , Adulto , Atenção/fisiologia , Testes com Listas de Dissílabos , Emoções , Feminino , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Caracteres Sexuais , Fala/fisiologia , Percepção Visual , Adulto Jovem
12.
Exp Brain Res ; 237(10): 2633-2643, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31384968

RESUMO

The Attentional-SNARC effect (Att-SNARC) originally described by Fischer et al. (Nat Neurosci 6(6):555, 2003), consists of faster RTs to visual targets in the left side of space when these are preceded by small-magnitude Arabic cues at central fixation and by faster RTs to targets in the right side of space when these are preceded by large-magnitude cues. Verifying the consistency and reliability of this effect is important, because the effect would suggest an inherent association between the representation of space and that of number magnitude, while a number of recent studies provided no positive evidence in favour of the Att-SNARC and the inherency of this association (van Dijck et al. in Q J Exp Psychol 67(8):1500-1513, 2014; Zanolie and Pecher in Front Psychol 5:987, 2014; Fattorini et al. in Cortex 73:298-316, 2015; Pinto et al. in Cortex, DOI:10.1016/j.cortex.2017.12.015, 2018). Here, we re-analysed Att-SNARC data that we have collected in 174 participants over different studies run in our laboratory. Most important, in a subsample of 79 participants, we also verified whether the strength and reliability of the Att-SNARC is eventually linked inter-individual variations in finger counting style, imagery vividness, and verbal/visual learning style. We found no evidence for the Att-SNARC effect or for the influence of finger counting style, imagery vividness, and learning style on its direction or consistency. These results confirm no inherent link between orienting of spatial attention and representation of number magnitudes. We propose that this link is rather determined by the joint use of spatial and number magnitude or parity codes in the performance of the numerical task at hand.


Assuntos
Atenção/fisiologia , Cognição/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Adulto , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Matemática , Reprodutibilidade dos Testes , Adulto Jovem
13.
Dev Cogn Neurosci ; 39: 100682, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31376589

RESUMO

Structural and functional neuroimaging studies show language and reading processes are left-lateralized, and associated with a dispersed group of left brain regions. However, it is unclear when and how asymmetry of these regions emerges. We characterized the development of structural and functional asymmetry of the language network in 386 datasets from 117 healthy children (58 male) across early childhood (2-7.5 years). Structural asymmetry was investigated using diffusion tensor imaging (DTI) and manual delineation of the arcuate fasciculus. Functional connectivity asymmetry was calculated from seed regions in the inferior frontal gyrus (IFG) and middle temporal gyrus (MTG). We show that macrostructural asymmetry of the arcuate fasciculus is present by age 2 years, while leftward asymmetry of microstructure and functional connectivity with the IFG increases across the age range. This emerging microstructural and functional asymmetry likely underlie the development of language and reading skills during this time.


Assuntos
Lateralidade Funcional/fisiologia , Desenvolvimento da Linguagem , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/crescimento & desenvolvimento , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/crescimento & desenvolvimento , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Imagem de Tensor de Difusão/métodos , Feminino , Neuroimagem Funcional/métodos , Humanos , Linguagem , Imagem por Ressonância Magnética/métodos , Masculino , Substância Branca/diagnóstico por imagem , Substância Branca/crescimento & desenvolvimento
14.
Behav Processes ; 167: 103911, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374226

RESUMO

Longitudinal research on manual preferences in humans and non-human primates has mainly been conducted from a developmental perspective, with only a few studies exploring long-term stability of this trait during adulthood. Therefore, we investigated short-term (1 year) and long-term (10 and 11 years) consistency of hand preference in a naturalistic group of 19 juvenile and adult chimpanzees (Pan troglodytes) by using two experimental tasks, one unimanual (simple reaching) and one bimanual (tube task). The experimental sessions were conducted in 2007, 2008 and 2018. We found that the direction of hand preference (right vs. left) in the tube task remained stable after both short-time and long-time periods. Conversely, hand preference direction for simple reaching was not consistent after the longest period (11 years), but the handedness indices (HI) between 2007 and 2008 (1-year period) and between 2008 and 2018 (10-year period) were positively correlated. The comparison between tasks confirmed that all the chimpanzees were more strongly lateralised for the tube task. Interestingly, however, the strength of hand preference in the tube task showed an increasing trend in the long term. We hypothesize that this could be a consequence of practice and experience with a particular motor action.


Assuntos
Lateralidade Funcional/fisiologia , Pan troglodytes/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Feminino , Masculino , Primatas , Fatores de Tempo
15.
IEEE Int Conf Rehabil Robot ; 2019: 101-107, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374614

RESUMO

Assessing proprioception is important for understanding and treating sensorimotor impairments. Many daily tasks require bimanual manipulation of objects, but state of the art methods for the assessment of proprioception are far away from bimanual activities, and instead evaluate sensorimotor integrity in oversimplified and often unimanual goal-directed tasks. Here, we developed a new device and method to assess proprioception and force production by simulating a realistic bimanual behavior. Twelve healthy participants held a physically coupled object - a sensorized box - and matched target orientations about the three principal axes without and with added weights. Our preliminary findings indicate that bimanual proprioception during orientation matching depends on the axis of rotation. For example, in rotations about the lateral axis of the body, underestimation and overestimation of the target angle depends on its orientation in a body-centered reference frame: participants tended to underestimate targets that required rotation far away from the body and overestimated angles that required rotation towards the body. We also found that for the same rotation axis, the larger were the rotations, the higher was the force applied. Moreover, we also found that fatigue causes undershoot in orientation matching. In the future, this tool could be adopted for assessment and treatment of sensorimotor deficits in bimanual functional tasks.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/fisiologia , Propriocepção/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Força da Mão , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
16.
BMC Neurosci ; 20(1): 38, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366317

RESUMO

BACKGROUND: In this study, nonlinear based time-frequency (TF) and time domain investigations are employed for the analysis of electroencephalogram (EEG) signals of mild cognitive impairment-Alzheimer's disease (MCI-AD) patients and healthy controls. This study attempts to comprehend the cognitive decline of MCI-AD under both resting and cognitive task conditions. RESULTS: Wavelet-based synchrosqueezing transform (SST) alleviates the smearing of energy observed in the spectrogram around the central frequencies in short-time Fourier transform (STFT), and continuous wavelet transform (CWT). A precise TF representation is assured due to the reassignment of scale variable to the frequency variable. It is discerned from the studies of time domain measures encompassing fractal dimension (FD) and approximate entropy (ApEn), that the parietal lobe is the most affected in MCI-AD under both resting and cognitive states. Alterations in asymmetry in the brain hemispheres are analysed using the homologous areas inter-hemispheric symmetry (HArS). CONCLUSION: Time and time-frequency domain analysis of EEG signals have been used for distinguishing various brain states. Therefore, EEG analysis is highly useful for the screening of AD in its prodromal phase.


Assuntos
Doença de Alzheimer/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Lateralidade Funcional/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Estudos de Casos e Controles , Disfunção Cognitiva/complicações , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Ondaletas
17.
Neuropsychology ; 33(8): 1101-1110, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31448940

RESUMO

OBJECTIVE: The concept of overlapping neural networks supporting both speech production and fine motor praxis is well accepted; however, few studies have explored the lateralized behavioral characteristics of both functions when performed simultaneously. METHOD: This study probes the characteristics of the dominant hemisphere by overloading cognitive processing via a novel dual-task paradigm. In 2 experiments, participants performed sets of motor and speech tasks under single-task and dual-task conditions. The sets of tasks differed as to the extent to which they relied on sequential processing, and we hypothesized that tasks more reliant on this type of processing would suffer a greater performance decrement under dual-task conditions. A reliable measure of hemispheric language dominance was obtained via functional transcranial Doppler (fTCD) ultrasound. RESULTS: Speech production scores in the experimental set (i.e., sequential processing) were consistently impaired under dual-task conditions, a distinction that was not seen in the control set. Results of Experiment 2 confirm those of Experiment 1, whereby speech scores were most strongly impaired under dual-task conditions, especially in the experimental set. Motor performance suffered less than speech performance in dual-task conditions in both the experimental and control sets across both experiments. CONCLUSION: Data suggest that the common processing capacity for speech and fine motor praxis can be disrupted through a dual-task paradigm. This novel behavioral data supports theories of a motor-based gestural origin for language and indicates that speech production is more sensitive to the effects of increased processing requirements than are motor skills. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Encéfalo/fisiologia , Função Executiva/fisiologia , Lateralidade Funcional/fisiologia , Destreza Motora/fisiologia , Rede Nervosa/fisiologia , Fala/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Neuroimagem Funcional , Humanos , Masculino , Rede Nervosa/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana , Adulto Jovem
18.
Biomed Res Int ; 2019: 5610849, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467897

RESUMO

Left-handers show lower asymmetry in manual ability when compared to right-handers. Unlike right-handers, left-handers do not show larger deactivation of the ipsilateral primary sensorimotor (SM1) cortex on functional magnetic resonance imaging when moving their dominant than their nondominant hand. However, it should be noted that morphometric MRI studies have reported no differences between right-handers and left-handers in volume, thickness, or surface area of the SM1 cortex. In this regard, magnetization transfer (MT) imaging is a technique with the potential to provide information on microstructural organization and macromolecular content of tissue. In particular, MT ratio index of the brain gray matter is assumed to reflect the variable content of afferent or efferent myelinated fibers, with higher MT ratio values being associated with increased fibers number or degree of myelination. The aim of this study was hence to assess, for the first time, through quantitative MT ratio measurements, potential differences in microstructural organization/characteristics of SM1 cortex between left- and right-handers, which could underlay handedness side. Nine left-handed and 9 right-handed healthy subjects, as determined by the Edinburgh handedness inventory, were examined with T1-weighted and MT-weighted imaging on a 3 T scanner. The hands of subjects were kept still during all acquisitions. Using FreeSurfer suite and the automatic anatomical labeling parcellations defined by the Destrieux atlas, we measured MT ratio, as well as cortical thickness, in three regions of interests corresponding to the precentral gyrus, the central sulcus, and the postcentral gyrus in the bilateral SM1 cortex. No significant difference between left- and right-handers was revealed in the thickness of the three partitions of the SM1 cortex. However, left-handers showed a significantly (p = 0.007) lower MT ratio (31.92% ± 0.96%) in the right SM1 central sulcus (i.e., the hand representation area for left-handers) as compared to right-handers (33.28% ± 0.94%). The results of this preliminary study indicate that quantitative MT imaging, unlike conventional morphometric MRI measurements, can be a useful tool to reveal, in SM1 cortex, potential microstructural correlates of handedness side.


Assuntos
Lateralidade Funcional/fisiologia , Movimento/fisiologia , Córtex Sensório-Motor/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Mãos/diagnóstico por imagem , Mãos/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Lobo Occipital/fisiologia , Córtex Sensório-Motor/diagnóstico por imagem
19.
Acta Psychol (Amst) ; 199: 102900, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31400650

RESUMO

There are many similarities and differences between the human hands and feet. On a psychological level, there is some evidence from clinical disorders and studies of tactile localisation in healthy adults for deep functional connections between the hands and feet. One form these connections may take is in common high-level mental representations of the hands and feet. Previous studies have shown that there are systematic, but distinct patterns of confusion found between both the fingers and toes. Further, there are clear individual differences between people in the exact patterns of mislocalisations. Here, we investigated whether these idiosyncratic differences in tactile localisation are shared between the fingers and toes, which may indicate a shared high-level representation. We obtained confusion matrices showing the pattern of mislocalisation on the hairy skin surfaces of both the fingers and toes. Using a decoding approach, we show that idiosyncratic differences in individuals' pattern of confusions are shared across the fingers and toes, despite different overall patterns of confusions. These results suggest that there is a common representation of the fingers and toes.


Assuntos
Dedos/fisiologia , Lateralidade Funcional/fisiologia , Dedos do Pé/fisiologia , Tato/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Física/métodos
20.
Behav Neurosci ; 133(4): 350-360, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31294590

RESUMO

Spatial judgment is impaired in Parkinson's disease (PD), with previous research suggesting that disruptions in attention and executive function are likely contributors. If judgment of center places demands on frontal systems, performance on tests of attention/executive function may correlate with extent of bias in PD, and attentional disturbance may predict inconsistency in spatial judgment. The relation of spatial judgment to attention/executive function may differ for those with left-side versus right-side motor onset (LPD, RPD), reflecting effects of attentional lateralization. We assessed 42 RPD, 37 LPD, and 67 healthy control participants with a Landmark task (LM) in which a cursor moved horizontally from the right (right-LM) or left (left-LM). The task was to judge the center of the line. Participants also performed neuropsychological tests of attention and executive function. LM group differences were found on left-LM only, with both PD subgroups biased leftward of the control group (RPD p < .05; LPD p < .01; no RPD-LPD difference). For left-LM trials, extent of bias significantly correlated with performance on the cognitive tasks for PD but not for the control group. PD showed greater variability in perceived center than the control group; this variability correlated with performance on the cognitive tasks. The correlations between performance on the test of spatial judgment and the tests of attention/executive function suggest that frontal-based attentional dysfunction affects dynamic spatial judgment, both in extent of spatial bias and in consistency of response as indexed by intertrial variability. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Doença de Parkinson/fisiopatologia , Navegação Espacial/fisiologia , Idoso , Atenção/fisiologia , Função Executiva/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Desempenho Psicomotor , Percepção Espacial/fisiologia
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