Olga Vasconcelos

ASYMMETRIES OF MANUAL MOTOR RESPONSE IN RELATION TO AGE, SEX, HANDEDNESS, AND OCCUPATIONAL ACTIVITIES '

Questions about left- and right-hand asymmetries require the analysis of preference and manual skill with respect to handedness. Hand preference and hand skill were examined in relation to sex, age, and occupational activities. 512 adults from manual, mixed, and intellectual activities and 253 children were tested for their manual preferences and performance. Analysis of variance followed by Scheffé post hoc tests, for right-handed adults, indicated significant effects for occupational activity and sex in dexterity and strength. Manual workers, under technological pressure, seemed more consistent in their manual preferences than their peers. For left-handed persons there were no significant effects. Dexterity and strength were also related to sex and age, suggesting different cultural opportunities for both sexes in relation to motor activities.

Lateral Manual Asymmetries: A Longitudinal Study From Birth to 24 Months

Longitudinal studies tracking the early development of manual asymmetries are fairly rare compared to the large number of studies assessing hand preference in infancy. Moreover, most prior longitudinal studies have performed behavioral observation over relatively short-time spans considering the celerity of early development. This study aims (i) to investigate the direction and consistency of manual lateral asymmetries over a longer period, from birth to 24 months of age, and (ii) to compare individual and group trajectories to better understand discrepancies between prior studies. Nineteen healthy infants were observed eight times in tasks that were adjusted progressively as infants manual skills developed. Results suggested two distinct periods in terms of the direction, strength, and consistency of manual preference. First, infants went through an initial phase characterized by a lack of lateral manual asymmetries. From 9 months of age, however, group analyses revealed an emerging and steadily growing right lateral bias over time, while individual trajectories revealed that the group-level right-bias formed progressively from a background of highly fluctuating and highly variable developmental trajectories.

Manual asymmetry in a complex coincidence- anticipation task: Handedness and gender effects

This study investigated the effects of handedness and gender on manual asymmetry in the performance of a complex coincidence-anticipation task. Left-handed (N=63) and right-handed (N=93) undergraduate students (78 males, 78 females) were required to press six buttons sequentially in conjunction with visual stimulation provided by a coincidence-anticipation apparatus. Participants were further separated into subgroups based on the degree of hand preference. Timing accuracy (AE, CE, VE) and timing response (IT, MT, AT) were analysed. Results showed that, concerning accuracy, (i) strong left-handers were more accurate than the other groups; (ii) performance with the preferred hand was superior to that of the non-preferred hand; and (iii) males outperformed females. Concerning timing response, (i) the preferred hand was faster than the non-preferred hand for movement time and (ii) males were faster in initiating the movement than females. These findings indicate that coincidence-anticipation competence appears to be influenced by hand preference, performing hand, and gender. In addition, findings are discussed in the framework of the hemispheric functional lateralisation for the planning and organisation of movement execution.

Stimulus velocity effect in a complex interceptive task in right- and left-handers

Abstract This study investigated stimulus velocity effect on manual asymmetry during planning and execution of a complex coincidence-anticipation task. Left- and right-handers were required to press six buttons sequentially in conjunction with visual stimulus provided by a coincidence-anticipation device. Results showed that (1) stimulus velocity affected timing response and timing accuracy only for right-handers, who responded faster but less accurately in the fast stimulus velocity, (2) manual asymmetries for both handedness groups revealed a left-hand advantage for initiating the movement, and a preferred-hand advantage for movement time. The preferred-hand advantage in timing accuracy was only observed in the fast stimulus velocity. These findings are discussed in the framework of the hemispheric functional lateralisation.

Perceived Somatotype as Indicator of Accuracy of Body Image, a Method Using Somatotype Attitudinal Distance

A method intended to assess accuracy of body image was applied to 52 Caucasian girls aged 14 and 15 years. Each girl, after being somatotyped by the Heath-Carter anthropometric method, was asked to select, among ten somatotype standard photographs, the one she perceived closest to her own objective somatotype. The purposes of the research were (i) to measure the distance between the objective and subjective judgements, self-perceived somatotypes by means of the somatotype attitudinal distance, and (ii) to assess the stability of the subjective somatotype by a test-retest correlation. The girls were also asked to select the pictures corresponding to the most preferred and aversive somatotypes. The test-retest coefficients were significant for the three somatotype choices. Hence, the method provides adequate stability and may be employed to reproduce the discrepancies between body image and real body build by a quantitative continuous measure.

A mixed-longitudinal study of children’s growth, motor development and cognition. Design, methods and baseline results on sex-differences

Abstract Background: There is a renewed interest in longitudinal studies which link children’s growth, motor and cognition development. This is important for both educational outcomes and identification of children who are at risk. Aim: To identify cross-sectional sex-differences. Subjects and methods: In total, 1166 Portuguese children, aged 4–11 years, were recruited into the Growth, Motor Development and Cognition Study (GMDC-Vouzela study). Measures included: anthropometry, gestational development, motor coordination, cognitive performance, laterality, physical fitness, metabolic syndrome risk, lifestyle characteristics and environmental exposures. Analysis of covariance was used to compare outcomes between boys and girls, adjusting for chronological age. Results: Most variables did not show significant differences between the sexes (p > 0.05). However, girls had more body fat mass than boys (p < 0.05) and boys were significantly heavier at birth (p < 0.05); furthermore, boys outperformed girls in a hopping high coordination test (p < 0.001) and were more physically fit (p < 0.05). Conclusions: Baseline results from the GMDC-Vouzela study indicate the dynamic relationships between childrens biological and environmental characteristics. They also highlight lifestyle traits that will most likely effect subsequent growth, motor and cognitive development.

Visuomotor memory in elderly: effect of a physical exercise program

O presente estudo pretendeu investigar o efeito do exercicio fisico (EF) na memoria visuomotora (MVM) de idosos em funcao do sexo e da idade. Foram testados 74 participantes com idades entre os 60 e os 90 anos, sendo 36 praticantes de EF (70,22 ± 0,90 anos) e 38 nao praticantes (68,26 ± 1,12 anos). A MVM foi avaliada atraves do teste de Thinus et al., sendo registado o tempo gasto na execucao do teste e o numero de erros durante a sua execucao. Atraves das ANOVAs grupo x genero e grupo x idade, os resultados demostraram um efeito significativo do grupo, mas nao do sexo e da idade, quer para o tempo de desempenho quer para os erros. Os praticantes apresentaram menores tempos e menos erros do que os nao praticantes. Conclui-se que o EF apresenta um efeito positivo na MVM, independentemente do sexo e da idade. Sugerem-se estudos longitudinais com um numero amostral superior e incluindo a aplicacao de um programa de EF, para melhor compreender o comportamento da MVM dos idosos.

COGNIÇÃO E ATIVIDADE FÍSICA: A RELAÇÃO EXISTENTE ENTRE ATENÇÃO E A VELOCIDADE PERCEPTIVA EM IDOSAS PRATICANTES E NÃO PRATICANTES DE ATIVIDADE FÍSICA

O Presente estudo teve como objetivo avaliar a Atencao (AT) e Velocidade Perceptiva (FI) numa populacao idosa, praticante e nao praticante de atividade fisica. Foram sujeitos da pesquisa 54 idosos do sexo feminino residentes na Cidade do Porto e pertencentes ao Centro de Investigacao em Atividade Fisica, Esporte e Lazer (CIAFEL) da Faculdade de Desporto da Universidade do Porto. Os instrumentos para mensuracao dos dados foram: os testes de Atencao Toulouse-Pieron (1982) e Figuras Identicas de Thurstone (1998) para afericao da velocidade perceptiva.

MEMÓRIA, EXERCÍCIO FÍSICO E ENVELHECIMENTO: UM ESTUDO SOBRE A RELAÇÃO EXISTENTE ENTRE A MEMÓRIA VISUOMOTORA E IDOSOS PRATICANTES E NÃO PRATICANTES DE ATIVIDADE FÍSICA

Este estudo teve como objetivo avaliar a memoria visuo-motora de idosos praticantes e nao-praticantes de atividade fisica. Foram sujeitos 70 voluntarios residentes na Cidade do Porto pertencentes ao Centro de Investigacao em Atividade Fisica, Saude e Lazer (CIAFEL) da Faculdade de Desporto da Universidade do Porto. O instrumento para mensuracao da memoria visuo-motora foi o teste de memoria visuo-motora adaptado de THINUS-BLANC et al., (1996). Os testes estatisticos utilizados utilizaram Statiscal Package for the Social Sciences (SPSS), versao 17.0., e compreenderam a analise de variância (p>=0,05). Da analise dos resultados, destacam-se as seguintes conclusoes: a memoria visuo-motora dos idosos em funcao da pratica de atividade fisica apresentou diferenca significativa nas variaveis de desempenho do teste visual-motor 1 e 2.