Posner Attention Task

Background

What draws attention? The Posner attention task measures reaction times to the appearance of certain stimuli after a variety of different types of cues. Subjects are told to focus on a fixation target, and after a set period of time are given a cue as to where the stimulus will apear. Cue types can beendogenous or exogenous, and valid or invalid. An endogenous cue is one which appears in the same place as the fixation target. The exogenous cue is one which appears in the place where the stimulus will appear. Cues are valid if the cue indicates to the subject where the stimulus will appear. A cue is invalid if the stimulus appears in a location that is not where the cue indicated. As might be expected, reaction times are faster when subjects are provided with valid cues compared to invalid cues.

Instructions

Fixate on the center cross. An arrow will replace the cross to indicate a direction (left or right) of where the stimulus will appear. Alternatively, either the left square or the right square will be highlighted with bold lines to cue the stimulus location. After the cue disappears, the stimulus will appear. Hit the space bar when you see the stimulus.