三维空间中视觉空间返回抑制对Simon效应的影响

通过虚拟现实技术构建虚拟三维场景,采用视觉空间返回抑制范式与Simon任务的变式相结合,操纵了目标深度、线索有效性以及空间一致性三个变量,考察三维空间深度位置上视觉空间返回抑制如何影响任务无关的反应表征(Simon效应)。结果发现,(1)三维空间深度位置上存在基于空间的返回抑制效应,且空间返回抑制效应会削减Simon效应;(2)目标出现在远处空间时,线索化条件下的Simon效应显著大于非线索化条件下的Simon效应;(3)目标出现在近处空间时,线索化条件与非线索化条件下的Simon效应之间无显著差异。研究表明,空间返回抑制并不是"深度盲",且目标的空间位置会对空间返回抑制与Simon效应的交互关系产生影响。

Influence of Visuospatial Inhibition of Return on Simon effect in Three-dimensional Space

It has been well documented that the anatomically independent attention networks in the human brain interact functionally to achieve goal-directed behaviors. By combining spatial inhibition of return (IOR) which implicates the orienting network with some executive function tasks (e.g ., the Stroop and the flanker tasks) which implicate the executive network, researchers consistently found that the interference effects are significantly reduced at cued compared to uncued locations, indicating the functional interaction between the two attention net works. However, a unique, but consistent effect is observed when spatial IOR is combined with the Simon effect: the Simon effect is significantly larger at the cued than uncued locations. Although the functional and anatomical interaction between the orienting and the executive networks have well established in two-dimensional (2D) space, little is known about their interaction in three-dimensional (3D) space. Therefore, in present study, we investigated the effect of spatial IOR on the task related response representation (Simon effect) in 3D space. In present study, by constructing a virtual 3D environment and presenting targets either closer to or father from the participants in an adapted version of Posner spatial-cuing paradigm, we made the classical experimental paradigm rotated 90°along the depth direction in 3D space, therefore, the experimental design was a 2 (depth of target: closer vs. farther) × 2 (cue validity: cued vs. uncued) × 2 (Simon congruency: congruent vs. incongruent) within-participants design, resulting in 8 experimental conditions in total and 60 trials in each of the experimental conditions. Due to the attending to space within (near space) and beyond (far space) arm’s reach is subserved by distinct brain circuits, we expected that the interaction between IOR and Simon effect was different in closer and farther depth plane.The main results showed, when targets appeared in the father depth plane, there was a interaction between cue validity and Simon congruency, F(1,22)=5.36, p<0.05. Futher tests on simple effects suggested that, at the incongruent condition, RTs to the cued target were significantly longer than RTs the uncued target, t(22)=3.36, p=0.005, a significant IOR effect (18ms); While, at the congruent condition, there was no difference between RTs to the cued target and RTs to the uncued target, t<1. Moreover, our results showed that the size of Simon effect was significantly larger at the cued location than at the uncued location, t(22)=2.31, p<0.05. However, when targets appeared in the closer depth plane, our results showed that only the main effect of cue validity was significant, F(1,22)=40.03, p<0.001, and there was no interaction between cue validity and Simon congruency, F<1. Taken together, by combining spatial IOR with the Simon task in 3D space, we found there were IOR effects at the depth direction in 3D, and we replicated the previous observation of larger Simon effect at the cued location of spatial IOR only when the target appeared in the farther depth plane, while there was no interaction between spatial IOR and the Simon task.