Efeito de diferentes demandas atencionais sobre os processos adaptativos do sistema de controle postural e do comportamento do olhar de adultos jovens
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2019-12-03
Autores
Brito, Matheus Belizário
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Universidade Estadual Paulista (Unesp)
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O objetivo do estudo foi investigar o efeito das tarefas visuais com diferentes demandas atencionais nos processos adaptativos do sistema de controle postural e no comportamento do olhar de adultos jovens frente à mudança abrupta da amplitude da sala móvel. Participaram do estudo quarenta e cinco adultos jovens (20,53 ± 2,04 anos). Foram mensurados o peso e a estatura corporal de todos os participantes. Ainda, os participantes realizaram o teste de Snellen para garantir acuidade visual normal entre todos os participantes. Em sequência, os participantes foram posicionados em pé sob uma plataforma de força (AMTI) dentro de uma “sala móvel”, utilizando o equipamento de rastreamento do olhar (ASL - H6) para calibração dos equipamentos. Os participantes foram divididos aleatoriamente em três grupos: 1-) Grupo Fixação (GFIX): no qual o participante permaneceu fixando o olhar em um alvo na parede frontal da sala; 2-) Grupo Movimentos Sacádicos Horizontais Imprevisíveis (GMSI): no qual os participantes realizaram movimentos sacádicos ora a direita e ora a esquerda a partir do centro da tela, envolvendo a incerteza de localização do alvo e 3-) Grupo Movimentos Sacádicos Horizontais Imprevisíveis com tarefa de Memória (GMSI-M), no qual os participantes realizaram a tarefa visual similar a do GMSI concomitante a uma tarefa de memorização de um número prédeterminado. Ao final de cada tentativa, o participante do GMSI-M deveria indicar quantas vezes este número apareceu. O alvo foi um círculo com 1,71 graus de diâmetro ou um “X”, de cor branca ou preta para contrastar comas listras pretas e brancas presentes nas paredes da sala. As condições de movimentação da sala foram: na primeira tentativa, a sala permaneceu estacionária. Nas tentativas 2, 3 e 4 (pré-mudança), a sala foi movimentada em amplitude baixa (amplitude: 0.6cm; frequência: 0.2Hz). Na quinta tentativa (mudança), a sala foi movimentada em amplitude alta (amplitude: 3.5cm; frequência: 0.2Hz), fornecendo uma mudança abrupta no ambiente. Nas tentativas 6, 7 e 8 (pós-mudança) os parâmetros da sala foram os mesmos da pré-mudança. Cada tentativa teve duração de 75 segundos e a cada três tentativas foi oferecido um minuto de descanso para os participantes. ANOVAS com medidas repetidas foram realizadas, tendo como fator: os grupos (GFIX, GMSI e GMSI-M) e as condições de mudança da sala (pré-mudança, mudança e pós-mudança). As variáveis dependentes destas análises foram: Amplitude Média de oscilação e Entropia nos eixos ântero-posterior (AP) e médio lateral (ML), Número de fixação, Duração Média das Fixações, Variabilidade da Duração Média das Fixações e o Tempo de Reação Sácadico. Ainda, MANOVAS foram realizadas, tendo como fatores os grupos e as condições de mudança da sala, semelhante ao das ANOVAS. Para a primeira MANOVA, as variáveis dependentes foram: Ganho e Fase. Para a segunda MANOVA, foram a Variabilidade de Posição e Variabilidade de Velocidade. Os resultados indicaram uma diminuição da amplitude média na direção AP, para o GMSI-M comparado ao GFIX (p=0,016), quando a sala estava estacionária. Foi encontrado uma maior amplitude média na direção AP durante a condição de mudança, comparado à pré-mudança (p=0,001) e pós-mudança (p=0,001) e uma menor Entropia, no eixo AP, durante a condição de mudança, comparado a condição de pré-mudança (p=0,002) e pós-mudança (p=0,001) quando a sala foi movimentada. Para as variáveis do acoplamento entre sala móvel e oscilação corporal, os resultados mostraram uma diminuição do Ganho durante a condição de mudança (p<0,0001) comparada à pré-mudança e pós-mudança, ainda houve um maior ganho durante a condição de pré-mudança comparado à pós-mudança (p=0,003). Além disso, os resultados mostraram uma menor Variabilidade de Posição e Velocidade durante a condição de mudança comparado a condição de pré-mudança (p<0,0001) e pós-mudança (p=0,001). Os resultados do olhar mostraram um menor número de fixações (p<0,0001) com maior duração média (p<0,0001) e variabilidade da duração das fixações (p<0,0001) para o GFIX comparado ao GMSI e GMSI-M. Ainda, as análises indicaram um maior tempo de reação sacádico para o GMSI-M comparado ao GMSI (p=0,016) e durante a condição de pós-mudança comparado a mudança (p=0,001). De modo geral, os resultados mostraram que os movimentos dos olhos não afetaram os processos adaptativos do sistema de controle postural de adultos jovens. Ademais, não foram encontradas diferenças entre os grupos para nenhuma das variáveis quando a sala foi movimentada, demonstrando que o sistema de controle postural apresenta processos adaptativos similares independentes do esforço adicional despendido na execução das tarefas concomitantes. Portanto, conclui-se que a adaptação do sistema de controle postural às alterações da sala móvel não é afetada pelos movimentos sacádicos dos olhos mesmo em situações de maior demanda atencional indicando que este mecanismo básico envolve baixo nível de atenção em adultos jovens.
The aim of this study was to investigate the effect of visual tasks with different attentional demands on the adaptive processes of the postural control system and eyes behavior of young adults during the implicit knowledge of altered moving room amplitude. Forty-five young adults (20.53 ± 2.04 years) participated in the study. Weight and height of all participants were measure. In addition, participants performed the Snellen Test to ensure visual acuity between all participants. After, they were positioned on a force plate (AMTI) inside a “moving room” using the eye tracking (ASL - H6) for equipment calibration. Participants were randomly divided into three groups: 1-) Fixation Group (GFIX): participant remained fixed at a target on the front wall of the room; 2-) Unpredictable Horizontal Saccade Movements Group (GMSI): participants performed saccades movements to the right and to left from the center of the screen, involving the uncertainty of the target location and 3-) Unpredictable Horizontal Saccade Movements Group with Memory task (GMSI-M): participant performed the visual task similar of the GMSI concomitantly with a number memorization task of a predetermined number. At the end of each trial, participants of the GMSI-M should indicated how many times this number appeared. The target was a circle with 1.71 degrees in diameter or an “X”, white or black because of the stripes on the walls of the room. The room movement conditions were: in first trial, the room remained stationary. In trials 2, 3 and 4 (pre-change), the room was moved at low amplitude (amplitude: 0.6cm; frequency: 0.2Hz). On the fifth trial (change), the room was moved at high amplitude (amplitude: 3.5cm; frequency: 0.2Hz), providing implicit information about the environment. In trials 6, 7, and 8 (post-change) room parameters were the same as pre-change. Each trial has duration of 75 seconds and every 3 trials one minute of rest was offered to the participants. Repeated measures ANOVAS were performed, having as a factor: the groups (GFIX, GMSI and GMSI-M) and the room change conditions (pre-change, change and post-change). The dependent variables of these analyzes were: Mean Sway Amplitude in Ântero-posterior (AP) and Mediolateral (ML) directions, Number of Fixations, Mean Fixation Duration, Variability of Mean Fixation Duration and the Saccades Reaction Time. Also, MANOVAS were performed. The factors, groups and room changing conditions are similar to ANOVAS. For the first MANOVA, the dependent variables were: Gain and Phase. For the second MANOVA, were the Variability of Position and Velocity. The results indicated a decrease in mean amplitude in the AP direction for GMSI-M compared to GFIX (p=0.016) when the room was stationary. A higher mean amplitude in the AP direction was found during the change condition compared to the pre-change (p=0.001) and post-change (p = 0.001) and a lower Entropy on the AP direction during the change condition compared the pre-change (p=0.002) and post-change (p=0.001) condition when the room was moved. For the coupling variables between moving room and body sway, the results showed a decrease in Gain during the change condition (p<0.0001) compared to the pre-change and post-change. Also, there was a greater gain during the pre-change compared to post-change (p=0.003). In addition, the results showed lower Position and Velocity Variability during the change condition compared to the pre-change (p<0.0001) and post-change (p=0.001) conditions. The results of the gaze showed a lower number of fixations (p<0.0001) with longer mean duration (p <0.0001) and Variability of fixation duration (p<0.0001) for GFIX compared to GMSI and GMSI-M. In addition, the analyzes indicated a longer time of acidic reaction for GMSI-M compared to GMSI (p=0.016) and during the post-change condition compared to change (p=0.001). Overall, the results showed that eye movements did not affect the adaptive processes of the young adults postural control system. Moreover, no differences were found between the groups for any of the variables when the room was moved, demonstrating that the postural control presents similar adaptive processes independent of the additional effort expended in performing the concurrent tasks. Therefore, it is concluded that the adaptation of the postural control system to changes in the moving room is not affected by saccadic eye movements even in situations of higher attentional demand indicating that this basic mechanism involves low attention to attentional capacity in young adults.
The aim of this study was to investigate the effect of visual tasks with different attentional demands on the adaptive processes of the postural control system and eyes behavior of young adults during the implicit knowledge of altered moving room amplitude. Forty-five young adults (20.53 ± 2.04 years) participated in the study. Weight and height of all participants were measure. In addition, participants performed the Snellen Test to ensure visual acuity between all participants. After, they were positioned on a force plate (AMTI) inside a “moving room” using the eye tracking (ASL - H6) for equipment calibration. Participants were randomly divided into three groups: 1-) Fixation Group (GFIX): participant remained fixed at a target on the front wall of the room; 2-) Unpredictable Horizontal Saccade Movements Group (GMSI): participants performed saccades movements to the right and to left from the center of the screen, involving the uncertainty of the target location and 3-) Unpredictable Horizontal Saccade Movements Group with Memory task (GMSI-M): participant performed the visual task similar of the GMSI concomitantly with a number memorization task of a predetermined number. At the end of each trial, participants of the GMSI-M should indicated how many times this number appeared. The target was a circle with 1.71 degrees in diameter or an “X”, white or black because of the stripes on the walls of the room. The room movement conditions were: in first trial, the room remained stationary. In trials 2, 3 and 4 (pre-change), the room was moved at low amplitude (amplitude: 0.6cm; frequency: 0.2Hz). On the fifth trial (change), the room was moved at high amplitude (amplitude: 3.5cm; frequency: 0.2Hz), providing implicit information about the environment. In trials 6, 7, and 8 (post-change) room parameters were the same as pre-change. Each trial has duration of 75 seconds and every 3 trials one minute of rest was offered to the participants. Repeated measures ANOVAS were performed, having as a factor: the groups (GFIX, GMSI and GMSI-M) and the room change conditions (pre-change, change and post-change). The dependent variables of these analyzes were: Mean Sway Amplitude in Ântero-posterior (AP) and Mediolateral (ML) directions, Number of Fixations, Mean Fixation Duration, Variability of Mean Fixation Duration and the Saccades Reaction Time. Also, MANOVAS were performed. The factors, groups and room changing conditions are similar to ANOVAS. For the first MANOVA, the dependent variables were: Gain and Phase. For the second MANOVA, were the Variability of Position and Velocity. The results indicated a decrease in mean amplitude in the AP direction for GMSI-M compared to GFIX (p=0.016) when the room was stationary. A higher mean amplitude in the AP direction was found during the change condition compared to the pre-change (p=0.001) and post-change (p = 0.001) and a lower Entropy on the AP direction during the change condition compared the pre-change (p=0.002) and post-change (p=0.001) condition when the room was moved. For the coupling variables between moving room and body sway, the results showed a decrease in Gain during the change condition (p<0.0001) compared to the pre-change and post-change. Also, there was a greater gain during the pre-change compared to post-change (p=0.003). In addition, the results showed lower Position and Velocity Variability during the change condition compared to the pre-change (p<0.0001) and post-change (p=0.001) conditions. The results of the gaze showed a lower number of fixations (p<0.0001) with longer mean duration (p <0.0001) and Variability of fixation duration (p<0.0001) for GFIX compared to GMSI and GMSI-M. In addition, the analyzes indicated a longer time of acidic reaction for GMSI-M compared to GMSI (p=0.016) and during the post-change condition compared to change (p=0.001). Overall, the results showed that eye movements did not affect the adaptive processes of the young adults postural control system. Moreover, no differences were found between the groups for any of the variables when the room was moved, demonstrating that the postural control presents similar adaptive processes independent of the additional effort expended in performing the concurrent tasks. Therefore, it is concluded that the adaptation of the postural control system to changes in the moving room is not affected by saccadic eye movements even in situations of higher attentional demand indicating that this basic mechanism involves low attention to attentional capacity in young adults.
Descrição
Palavras-chave
Controle postural, Comportamento do olhar, Adultos jovens