The Posner Cueing Tast is a neuropsychological test often used to assess attention.
It assesses a person's ability to perform an attentional shift. It has been used and modified to assess the effects of experimental manipulations on spatial attention.
In this task participants need to indicate which side a target appears on by pressing the corresponding arrow key as quickly as possible. Before the target appears, an arrow is displayed as a cue. The arrow can be valid (facing the same direction where the target will appear, or invalid where it points in the opposite direction to the subsequent target thereby 'cueing' one or both locations
Posner, M. I. (1980). "Orienting of attention". Quarterly Journal of Experimental Psychology. 32 (1): 3–25.