| Abstrakt: |
Fluctuations in the force of a goal-directed sustained contraction can be influenced by age, vision, and physiological arousal. Additionally, when no goal force is required, exposure to unpleasant images leads to increased sustained force production. The purpose of the present study was to determine how emotional state modulates force production during a goal-directed sustained pinch grip task. Participants (N = 39) performed 35 trials. On each trial, a 10% MVC pinch grip was sustained as accurately as possible across three sequential stages: feedback only (4 s), exposure to an affective image with no feedback (6 s) (adventure, erotica, attack, mutilation, or neutral), and feedback only (4 s). Manipulated trials were compared with a control condition during which no image was presented to ensure visual feedback throughout the entire trial. Root mean square error (RMSE) and information transmission (IT) were calculated for each of four 1-s epochs that were extracted from the exposure period. In line with prediction, RMSE was stable during the control condition and progressively increased during the no feedback conditions. Notably, greater RMSE was evidenced during Epoch 4 when exposed to neutral and adventure images as compared with all epochs during exposure to mutilation images, Epochs 1-3 during erotica and attack images, and Epochs 1-2 during adventure and neutral images. Contrary to prediction, therefore, increases in arousal of the displayed image generally attenuated movement error. Corroborating previous research, removal of visual feedback reduced IT. Additionally, increases in IT were evidenced during erotica and mutilation images as compared with attack and neutral exposure periods. Thus, when performing a goal-directed sustained movement without visual feedback, increased arousal resulted in greater IT and less error relative to movements performed under comparatively reduced arousal. Implications and future research directions are offered while integrating conceptual notions of emotional interference, emotion regulation, and motor control. [ABSTRACT FROM AUTHOR] |
