Efeito do ciclo menstrual sobre as representações da ação

Abstract

Introduction: Sexual dimorphism is relevant in Sports and Exercise Medicine and Rehabilitation. Hormonal fluctuations during the menstrual cycle are unique to females and can affect the performance of visual perception and motor skills. Much of the movement production is based on the recruitment of endogenous representations of action. However, the motor repertoire is sensitive to several internal and external factors, such as laterality, dominance and geometric shapes. Hormonal factors influence abilities between the sexes in tasks such as linguistic ability, memorization and perception of biological movement. Thus, we want to investigate whether representations of action are sensitive to hormonal fluctuations in females. Objective: To evaluate the effect of the phases of the menstrual cycle on representations of action, such as action prediction, perception of biological movement, spatial perception, memorization and reaction time. Methods: The study will involve 20 participants and will be carried out at the Athletica Life&Sports clinic. A comparative design will be used, observing motor and mainly cognitive variables during two phases of the menstrual cycle, follicular and luteal, collected between the 4th and 7th postmenstrual day and the 5th and 3rd premenstrual day, respectively. Reaction time tests will be applied using light capsules (BlazePod®) in which the volunteer performs the greatest number of touches in the shortest possible time; visual memory, which consists of checking the regression of the light points; geometric-spatial perception, which consists of analyzing and checking mental rotations of geometric figures; visual perception of kinematic law (power law 2/3), where the test asks the volunteers to modulate the speed of movement of the light point, pressing the space bar when the movement presents linear speed in both curved and straight moments; and prediction of biological action using a handgrip task, psychophysical videos of contact between hand and object were presented to volunteers on a computer screen. In half of the videos, 50% of the final trajectory was occluded, while in the other half there was not occluded. Participants pressed the space bar on the keyboard to predict the moment of contact between the hand and the object. Data analysis: Data will be compared between these two periods using a paired t-test or a repeated measures ANOVA. The significance level will be set at p <0.05. In cases of significant effects, we will use the Holm post-hoc test. Results: In the analysis of five tests involving seven variables among three subgroups, only the number of touches variable in the reaction time test showed a statistically significant difference, specifically in the comparison between the luteal group and the control group (p < 0.05). The remaining results, although indicating a trend toward better performance in the follicular group, did not reach the statistical threshold for significance (p > 0.05). Conclusion: The results showed significance only for the number of touches variable in the comparison between the luteal and control groups. These findings suggest that the hormonal influence on action representations may be limited and non-linear or may even depend on other factors not included in the study.