A predição de uma ação transitiva é modulada pela valência emocional do objeto

Abstract

Recent experimental evidences demonstrate that the action observation and action execution directed to objects (i.e., transitive action) shared similar motor areas. This action-perception network is involved in our ability to predict the sensory consequences of actions performed by others. Thus, the main objective of the present work was to evaluate the effect of an object's emotional valence on to the action prediction process. For this, 38 undergraduate students were recruited to watch reach-to-grasp videos directed of pleasant, unpleasant or neutral objects on a computer screen. Two visual conditions were included: occlusion (a black rectangle occluded the last 50% of the movement) and full vision. In total, 90 repetitions were performed (2 visual conditions x 3 valences x 15 repetitions). The experiment always started with the occlusion block. The participant's task consisted in predict the time-to-contact (TTC) between the hand and the object by pressing the space bar on the keyboard. Prediction errors were calculated based on the temporal difference (ms) between the participants' prediction of TTC and the contact times of our videos. An ANOVA for repeated measures (2 visual conditions x 3 valences) was used to compare the prediction errors. The Tukey post-hoc test was used to compare the significant effects (p <0.05). Our results suggest that the prediction of action is modulated by the emotional valence of the object. We found a valence effect with a greater temporal precision for AGR and NEU objects when compared to DES. There was no visual effect on action prediction. Finally, we observed that the visual condition only modulated the prediction of the action directed to AGR and NEU objects. To our knowledge, this is the first behavioral demonstration that the emotional valence of objects interferes within the action prediction process. These results may contribute in the future to the development of complementary protocols to traditional motor rehabilitation.