Ghahghaei Saeideh, Verghese Preeti
The Smith-Kettlewell Eye Research Institute, San Francisco, CA, USA.
J Vis. 2017 Feb 1;17(2):10. doi: 10.1167/17.2.10.
Attention is important for selecting targets for action. Several studies have shown that attentional selection precedes eye movements to a target, and results in an enhanced sensitivity at the saccade goal. Typically these studies have used isolated targets on blank backgrounds, which are rare in real-world situations. Here, we examine the spatial profile of sensitivity around a saccade target on a textured background and how the influence of the surrounding context develops over time. We used two textured backgrounds: a uniform texture, and a concentric arrangement of an inner and an outer texture with orthogonal orientations. For comparison, we also measured sensitivity around the target on a blank background. The spatial profile of sensitivity was measured with a brief, dim, probe flashed around the saccade target. When the target was on a blank or a uniformly textured background, spatial sensitivity peaked near the target location around 350 ms after cue onset and declined with distance from the target. However, when the background was made up of an inner and outer texture, sensitivity to the inner texture was uniformly high, peaking at about 350 ms after cue onset, suggesting that the entire inner texture was selected along with the target. The enhancement of sensitivity on the inner texture was much smaller when observers attended the target covertly and performed the probe-detection task. Thus, our results suggest that the surface representation around the target is taken into account when an observer actively plans to interact with the target.
注意力对于选择行动目标很重要。多项研究表明，注意力选择先于眼睛向目标的移动，并导致在扫视目标处的敏感性增强。通常这些研究使用空白背景上的孤立目标，而这在现实世界情况中很少见。在这里，我们研究了有纹理背景上扫视目标周围的敏感性空间分布，以及周围环境的影响如何随时间发展。我们使用了两种有纹理的背景：一种均匀纹理，以及一种内部和外部纹理呈正交方向的同心排列。为了进行比较，我们还测量了空白背景上目标周围的敏感性。敏感性的空间分布是通过在扫视目标周围短暂、暗淡地闪现探测刺激来测量的。当目标位于空白或均匀纹理背景上时，空间敏感性在提示开始后约350毫秒在目标位置附近达到峰值，并随着与目标距离的增加而下降。然而，当背景由内部和外部纹理组成时，对内部纹理的敏感性始终很高，在提示开始后约350毫秒达到峰值，这表明整个内部纹理与目标一起被选中。当观察者 covertly 关注目标并执行探测检测任务时，内部纹理上敏感性的增强要小得多。因此，我们的结果表明，当观察者积极计划与目标互动时，会考虑目标周围的表面表征。
