A dominância manual afeta a predição motora durante a observação de uma ação dirigida a um objeto?

Abstract

Introduction: Voluntary movements imply a predictive control that ensures the anticipation of sensory-motor consequences related to the execution and observation of actions. According to the literature, handedness influences the pattern of neural activation during manual action observation. Aim: To investigate whether the prediction of manual actions object-directed varies according to handedness during observation. Methodology: Videos of actions toward to manipulable objects were presented to twenty healthy subjects (age: 21.70 ± 3.88 years). Next, the subjects reconstructed the observed actions chronologically (from the beginning to the end of the action) or reversely (from the back to the beginning of the action) based on frames taken from the same videos. The videos started with the actor with his hand in the resting position, and then the hand moved, right or left, towards the object. Thus, after interaction with the object, the natural and expected outcome of the observed action is the hand return to the resting position. The parameter measured in this protocol was the response time to start the reconstruction of the observed action. Results: Left-handed subjects have a longer response time than right-handed individuals to start the task. In addition, the response time was longer during the chronological condition of frame organization when compared to the reverse situation, suggesting that the neural mechanisms activated for both conditions differ in some way and the predictive mechanism seems to be more readily activated. Conclusion: The present study indicates that the handedness of a subject and the laterality of the hand observed acting seem not to modulate the response time within a paradigm of reconstruction of a manual action.