Effects of visual and auditory stimuli in a choice reaction time task

The effect produced by a warning stimulus(i) (WS) in reaction time (RT) tasks is commonly attributed to a facilitation of sensorimotor mechanisms by alertness. Recently, evidence was presented that this effect is also related to a proactive inhibition of motor control mechanisms. This inhibition would hinder responding to the WS instead of the target stimulus (TS). Some studies have shown that auditory WS produce a stronger facilitatory effect than visual WS. The present study investigated whether the former WS also produces a stronger inhibitory effect than the latter WS. In one session, the RTs to a visual target in two groups of volunteers were evaluated. In a second session, subjects reacted to the visual target both with (50% of the trials) and without (50% of the trials) a WS. During trials, when subjects received a WS, one group received a visual WS and the other group was presented with an auditory WS. In the first session, the mean RTs of the two groups did not differ significantly. In the second session, the mean RT of the two groups in the presence of the WS was shorter than in their absence. The mean RT in the absence of the auditory WS was significantly longer than the mean RT in the absence of the visual WS. Mean RTs did not differ significantly between the present conditions of the visual and auditory WS. The longer RTs of the auditory WS group as opposed to the visual WS group in the WS-absent trials suggest that auditory WS exert a stronger inhibitory influence on responsivity than visual WS

Facilitatory effects of an auditory warning stimulus in a visual location identification task and a visual shape identification task

The occurrence of a weak auditory warning stimulus increases the speed of the response to a subsequent visual target stimulus that must be identified. This facilitatory effect has been attributed to the temporal expectancy automatically induced by the warning stimulus. It has not been determined whether this results from a modulation of the stimulus identification process, the response selection process or both. The present study examined these possibilities. A group of 12 young adults performed a reaction time location identification task and another group of 12 young adults performed a reaction time shape identification task. A visual target stimulus was presented 1850 to 2350 ms plus a fixed interval (50, 100, 200, 400, 800, or 1600 ms, depending on the block) after the appearance of a fixation point, on its left or right side, above or below a virtual horizontal line passing through it. In half of the trials, a weak auditory warning stimulus (S1) appeared 50, 100, 200, 400, 800, or 1600 ms (according to the block) before the target stimulus (S2). Twelve trials were run for each condition. The S1 produced a facilitatory effect for the 200, 400, 800, and 1600 ms stimulus onset asynchronies (SOA) in the case of the side stimulus-response (S-R) corresponding condition, and for the 100 and 400 ms SOA in the case of the side S-R non-corresponding condition. Since these two conditions differ mainly by their response selection requirements, it is reasonable to conclude that automatic temporal expectancy influences the response selection process

Assimetrias funcionais em pacientes com hemiparesia: uma revisão da literatura

Deficits funcionais decorrentes de lesões encefálicas unilaterais, bem como as diferenças entre pacientes que sofreram lesão no hemisfério esquerdo e pacientes que sofreram lesão no hemisfério direito, são descritos na literatura. Há, no entanto, poucos dados comparativos sobre como esses dois grupos de pacientes se recuperam. Considerando que a ocorrência de uma diferença importante nessa recuperação poderia implicar a necessidade de utilização de condutas de reabilitação específicas para cada caso, é importante a revisão do que foi investigado até o momento sobre o assunto. Este estudo visou rever dados da literatura referentes à recuperação de indivíduos com lesão hemisférica e também destacar as diferenças entre lesões à esquerda e à direita e as respectivas abordagens fisioterapêuticas.Physical impairment in patients with unilateral brain lesions and the differences between patients with left- and right-hemisphere lesions have been extensively described in the literature. However, few studies compared the recovery of patients with left- and right-hemisphere lesions. In view of theimportant differences between the latter, and the respectively specific rehabilitation approaches, it is important to verify what has been investigatedon the recovery of each side lesion. This study aimed to review the existingdata about rehabilitation of patients with hemispheric lesions and also toevidence the differences between left- and right-hemisphere lesions and thecorresponding therapeutic approaches

The influence of educational status on motor performance and learning: a literature review

Many studies have shown the impact of the educational status on cognitive and motor control. However, few studies in the area of Physical Therapy and Motor Behavior consider the educational status of the subjects. This study aimed to describe evidences about the influence of the educational status on motor behavior (and its repercussions on physiotherapeutic assessment) and on motor learning (and its repercussions on physiotherapeutic treatment). We included in this review national and international studies from 1998 to 2013 from SciELO, MEDLINE and LILACS databases. We used the keywords: educational status, schooling level, motor control, motor behavior, motor performance, and motor learning. Sixty studies were located and 28 were selected, because they followed the inclusion criteria: (1) to investigate the effect of education on motor performance; (2) be available in Portuguese or English; and (3) be available in Brazil. The review showed that the educational status of patients must be considered by the physiotherapists in experimental and clinical practice, because many studies have shown its influence on assessment and treatment of young and older adults.Muchos estudios han demostrado el impacto de la educación en las habilidades cognitivas y motoras. Sin embargo, muy pocos estudios en el campo de la Terapia Física y Comportamiento Motor consideran la escolarización en la muestra. Este estudio tuvo como objetivo describir la evidencia sobre la influencia de la educación en el comportamiento motor (y sus efectos sobre la evaluación de terapia física) y aprendizaje motor (y sus repercusiones en la fisioterapia). Un sondeo 1998-2013 buscó revistas nacionales e internacionales en las bases de datos SciELO, MEDLINE y LILACS, utilizando las palabras clave: educación, nivel de educación, control de motores, el comportamiento del motor, el rendimiento del motor y de aprendizaje motor. Se localizaron 60 estudios. De éstos, 28 fueron seleccionados porque cumplen con los criterios de inclusión: (1) investigar el efecto de la educación sobre el rendimiento del motor; (2) estar en Portugués o Inglés; y (3) estará disponible en Brasil. La revisión mostró que la educación de los pacientes debe ser considerada por los fisioterapeutas en situaciones experimentales y clínicos, ya que varios estudios han demostrado su influencia en la evaluación y el tratamiento de jóvenes y ancianosMuitos estudos têm mostrado o impacto da escolaridade na cognição e motricidade. Porém, ainda poucos estudos na área de Fisioterapia e Comportamento Motor consideram a escolaridade da amostra. Este trabalho visou descrever evidências sobre a influência da escolaridade no comportamento motor (e suas repercussões na avaliação fisioterapêutica) e na aprendizagem motora (e suas repercussões no tratamento fisioterapêutico). Um levantamento de 1998 a 2013 buscou periódicos nacionais e internacionais nas bases de dados SciELO, MEDLINE e LILACS, com os descritores: escolaridade, nível educacional, controle motor, comportamento motor, desempenho motor e aprendizagem motora. Foram localizados 60 estudos. Desses, 28 foram selecionados por atenderem aos critérios de inclusão: (1) investigar o efeito da escolaridade sobre o desempenho motor; (2) estar em português ou inglês; e (3) estar disponível no Brasil. A revisão mostrou que a escolaridade dos pacientes deve ser considerada pelos fisioterapeutas em situações experimentais e clínicas, pois diversos estudos mostraram sua influência na avaliação e no tratamento de jovens e idosos

Influence of cueing on the preparation and execution of untrained and trained complex motor responses

This study investigated the influence of cueing on the performance of untrained and trained complex motor responses. Healthy adults responded to a visual target by performing four sequential movements (complex response) or a single movement (simple response) of their middle finger. A visual cue preceded the target by an interval of 300, 1000, or 2000 ms. In Experiment 1, the complex and simple responses were not previously trained. During the testing session, the complex response pattern varied on a trial-by-trial basis following the indication provided by the visual cue. In Experiment 2, the complex response and the simple response were extensively trained beforehand. During the testing session, the trained complex response pattern was performed in all trials. The latency of the untrained and trained complex responses decreased from the short to the medium and long cue-target intervals. The latency of the complex response was longer than that of the simple response, except in the case of the trained responses and the long cue-target interval. These results suggest that the preparation of untrained complex responses cannot be completed in advance, this being possible, however, for trained complex responses when enough time is available. The duration of the 1st submovement, 1st pause and 2nd submovement of the untrained and the trained complex responses increased from the short to the long cue-target interval, suggesting that there is an increase of online programming of the response possibly related to the degree of certainty about the moment of target appearance.CAPESCAPESCNPq-PIBICCNPqPIBI

Os componentes motor e visual de uma tarefa-dupla devem ser associados ou isolados durante o treinamento?

The association of tasks (dual-task) has functional importance in daily activities; people usually have to learn new tasks. It is unclear whether tasks should be trained isolated or associated. This experiment aimed at verifying whether the best dual-task performance occurs after training isolated or associated tasks. Twenty volunteers underwent initial assessment, training, and final assessment; ten trained associated tasks (AT) and the others trained tasks separately (IT). The motor task consisted of alternating steps between the ground and a platform. The visual task measured the ability to name two visual stimuli displayed on a computer screen (bus or truck). The number of step alternations per second in the absence and presence of the visual task, and the number of errors in the visual task in the absence and presence of the motor task, were counted and statistically analysed. The AT group showed both motor (initial 1.10 alternations/s, final 1.25 alternations/s; p=0.028) and visual (initial 9.3 errors, final 6.9 errors; p=0.039) improvement in performance. The same did not occur to the IT group: motor improvement did not reach significance level, probably due to the higher variability in the number of step alternations per second during training, and no visual improvement was shown (p=0.844). It may thus be said that the kind of training interfered on performance. The best performance occurred after dual-task training.As atividades diárias requerem o desempenho simultâneo de tarefas (tarefa-dupla), não estando claro se seu treino deve ser realizado com tarefas isoladas ou associadas. Este estudo visou verificar se a aquisição de uma tarefa-dupla ocorre por meio do treinamento de tarefas isoladas ou associadas. Vinte voluntárias foram submetidas a avaliação inicial, treinamento e avaliação final. Dez treinaram as tarefas associadas (TA) e as demais, isoladas (TI). A tarefa motora consistia na alternância de passos do chão a uma plataforma. A tarefa visual consistia na nomeação de dois estímulos (ônibus ou caminhão), um no centro e outro na periferia da tela do computador. O número de passos por segundo na ausência e na presença da tarefa visual, e o número de erros na tarefa visual na ausência e na presença da tarefa motora, foram contados e comparados estatisticamente. O grupo TA apresentou melhora tanto no desempenho motor (inicial 1,10 alternâncias/s, final 1,25 alternâncias/s, p=0,028), quanto no desempenho visual (inicial 9,3 erros, final: 6,9 erros, p=0,039). O mesmo não ocorreu com o grupo TI: a melhora motora não atingiu nível significativo, provavelmente devido à maior variabilidade no número de alternâncias de passo por segundo durante o treinamento, e não houve melhora visual significativa (p=0,844). Portanto, o tipo de treinamento interferiu no desempenho. O melhor desempenho ocorreu após o treinamento da tarefa-dupla

Interferência mútua entre atividade visual e atividade motora em jovens e idosos

Since aging brings about difficulty in dividing attention, this study aimed at verifying, in youth and aged: (1) the possible interference between a visual and a motor task; (2) whether such interference varies between young and elderly subjects; (3) whether there is correlation between the proposed tasks and the trail making test (TMT) and the timed up-and-go test (TUGT). The visual task measured the ability to state whether two quickly presented figures were same or different. The motor task consisted on alternating steps from the ground to a 10 cm-high platform. Tasks were assessed both as single-task (isolated) and dual-task (simultaneous) in two groups: 10 young people (aged 23±2.8) and 10 elderly (aged 68.8±8.6). In the visual task, young volunteers presented less errors than the elderly (pComo o envelhecimento provoca dificuldade na capacidade de dividir a atenção, este estudo visou verificar, em jovens e idosos: (1) a eventual interferência entre uma tarefa visual e uma motora; (2) se essa interferência (caso exista) ocorre de forma diferente no desempenho de jovens e idosos; (3) se as tarefas propostas têm correlação com testes validados, de seqüência alfanumérica (TMT) e de levantar e caminhar cronometrado (TLCC). A tarefa visual consistiu na verbalização do reconhecimento de duas figuras iguais ou diferentes apresentadas rapidamente. A tarefa motora consistiu na alternância de passos do chão a uma plataforma fixa de 10 cm de altura. As tarefas foram avaliadas isoladas (tarefa-simples) e associadas (tarefa-dupla) em dois grupos: 10 jovens (23±2,8 anos) e 10 idosos (68,8±8,6 anos). Na tarefa visual, os jovens fizeram menos erros que os idosos (

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio