[Effects of spatial orientation on attention reaction time during pointing movement towards visual direction]. / Effets de l'orientation spatiale de l'attention sur le temps de réaction lors du mouvement de pointage sur une cible visuelle.

ABSTRACT

In the present study, it was consequently proposed to investigate how the spatial orientation of attention made by the explicit and implicit components of advance information, affected the reaction time (RT) performances. Subjects performed a simple RT task with an orientation cue and two choice RT situations, the one with a neutral cue and the other with a primed cue. The motor task to be performed consisted of pointing towards a visual target. The mechanisms involved in the orientation of attention were studied on the one hand by analysing the effects of the preparatory signal, which explicitly oriented the subjects' attention towards the forthcoming target position, and on the other hand, by examining whether the reinforced probability of warning stimulus(WS) and imperative stimulus (IS) being compatible affected the subjects' performances, i.e., whether they detected and made use of the information implicitly conveyed that there existed a bias in favour of the probability that IS would appear in the direction predicted by WS. The results of this study show that the subjects shortened their RTs by using both the explicit(auditory) and the implicit(probability-related) information with which they were provided prior to performing the movement. These data on the effects of the oriented auditory signal on the reaction times indicate that in our experiments, by orienting their attention depending on the position of the stimuli, the subjects were able to reduce their reaction times. The significant correlation found to exist here between the level of probability associated with the position of the WS and the choice RT values indicates that also the implicit information as to the WS-IS compatibility was taken into account by the subjects in all the situations.