ABSTRACT
The principle of Fitts' law explains that the difficulty of movement increases when targets are farther away and narrower in width, particularly when touching two parallel targets as quickly as possible. Understanding the differences in motor and gaze behaviors between extroverts and introverts when performing tasks that require speed and accuracy is crucial for the development of sensor-based interfaces for games and rehabilitation. This study aimed to investigate such differences in a computer task that assesses the speed-accuracy trade-off (Fitts' task). Twenty introverts and seventeen extroverts wore an eye tracker and an accelerometer attached to their hand while performing 12 trials through six levels of difficulty presented on a computer screen. The results showed that introverts had longer visual fixations at the higher difficulty levels and reduced pupil diameter variability when difficulty was intermediate, suggesting that their gaze behavior may be different from that of extroverts. However, no significant differences were found in the speed and accuracy performance or kinematic variables between extroverts and introverts. These findings have important implications for the design of interventions that require both speed and accuracy in movement, such as in the development of virtual reality/games for rehabilitation purposes. It is important to consider individual differences in motor and gaze behaviors, particularly in those who may struggle with longer visual fixations, for the design of sensor-based applications and to promote successful interventions and recovery.
Subject(s)
Extraversion, Psychological , Psychomotor Performance , Movement , Personality , ComputersABSTRACT
Extraverts are active and talkative, while introverts are quiet and calm. This difference has been attributed to the cortical activation level (arousal), which is low in extraverts and high in introverts. Thus, to reach an optimal level of arousal, extraverts seek stimulation and introverts avoid it. As caffeine increases arousal levels, our primary aim was to investigate the effect of caffeine on the performance of extraverted and introverted university students in the execution of stability, manipulative, and locomotor tasks. Considering the above, we evaluated side effects, such as restlessness and trembling of hands, we also analyzed the individual's perception regarding caffeine intake and the placebo. Forty two volunteers were classified as 21 extraverts and 21 introverts by the Eysenck Personality Questionnaire. Participants performed three tasks on two different days, having previously ingested caffeine and a placebo in counterbalanced order. A double-blind technique was employed. The dependent variable was the execution time to perform the tasks. The analyses of variance [2 (extraversion/introversion) x 2 (caffeine x placebo)] for each task did not show significant differences. Regarding the secondary aim, the chi-square test showed that introverts had a better perception of the substance they had ingested than did extraverts. Our findings indicate that in the execution of stability, manipulative, and locomotor tasks, either caffeine or the placebo produced the same effect, regardless of the participants' extraversion score. In addition, introverts were more sensitive to perceive which substance was ingested, caffeine or the placebo, than extraverts.
ABSTRACT
ABSTRACT Introduction: Extraversion/introversion and age differences might influence speed-accuracy tradeoff. Objective: The speed-accuracy tradeoff was investigated in extroverted and introverted female children, young adults and older adults. Method: Participants carried out an alternative version of Fitts' task, which involved making alternate clicks with the mouse held in the dominant hand, moving as fast as possible, on two rectangular targets on a computer screen in order to make twelve attempts at six random levels of difficulty (twelve combinations of target widths and distances between targets). Each of the three groups was composed of 16 introverted and 16 extroverted subjects, based upon Brazilian versions of Eysenck's questionnaire. Results: Elderly introverts fell short of the target more often and committed more overall errors than the elderly extroverts. Additionally, compared to their younger adult counterparts, the elderly subjects fell short of the target more often and committed more overall errors, besides taking longer to complete the task with higher levels of difficulty. Conclusion: The findings were interpreted in light of theories designed to explain the main processes underlying extroversion/introversion and age-related differences. Level of Evidence II; Lesser quality prospective study.
RESUMO Introdução: Diferenças de extroversão/introversão e idade podem influenciar na troca velocidade-precisão. Objetivo: A troca velocidade-precisão foi investigada em garotas, jovens adultas e idosas extrovertidas e introvertidas. Método: As participantes realizaram uma versão alternativa da tarefa de Fitts, a qual consistia em clicar alternadamente com a mão dominante no mouse, o mais rápido possível, em dois alvos retangulares na tela do computador, a fim de fazer doze tentativas em seis níveis aleatórios de dificuldade (doze combinações de larguras e distâncias entre os alvos). Cada um dos três grupos era composto por 16 introvertidas e 16 extrovertidas, com base nas versões brasileiras do questionário de Eysenck. Resultados: As idosas introvertidas acertaram menos o alvo com mais frequência e cometeram mais erros gerais em comparação às idosas extrovertidas. Ainda, as idosas acertaram menos o alvo com mais frequência e cometeram mais erros gerais, além de demorarem mais tempo para concluírem as tarefas com níveis maiores de dificuldade quando comparadas com as jovens adultas. Conclusão: Os achados foram interpretados com base nas teorias criadas para explicarem os principais processos sobre as diferenças relacionadas à extroversão/introversão e à idade. Nível de Evidência II; Estudo prospectivo de menor qualidade.
RESUMEN Introducción: Las diferencias de extroversión/introversión y edad pueden influir en el cambio velocidad-precisión. Objetivo: El cambio velocidad-precisión fue investigado en mujeres jóvenes adultas y de la tercera edad introvertidas y extrovertidas. Método: Las participantes realizaron una versión alternativa de la tarea de Fitts, que consistía en hacer clic alternadamente con el ratón, usando la mano dominante, lo más rápidamente posible, en dos objetos rectangulares en la pantalla de la computadora, a fin de realizar doce tentativas con seis niveles aleatorios de dificultad (doce combinaciones de anchos y distancias entre los objetos). Cada uno de los tres grupos fue compuesto por 16 introvertidas y 16 extrovertidas, con base en las versiones brasileñas del cuestionario de Eysenck. Resultados: Las mujeres de tercera edad introvertidas acertaron menos el objeto con más frecuencia y cometieron más errores generales en comparación a las mujeres de tercera edad extrovertidas. Además, las mujeres de tercera edad acertaron menos el objeto con más frecuencia y cometieron más errores generales, además de demorar más tiempo para concluir las tareas con niveles mayores de dificultad cuando comparadas con las mujeres jóvenes adultas. Conclusión: Los hallazgos fueron interpretados con base en las teorías creadas para explicar los principales procesos sobre las diferencias relacionadas a la extroversión/la introversión y a la edad. Nivel de Evidencia II; Estudio prospectivo de menor calidad.
