Attention Can Impair Visual Perception

Visual stimuli with more contrast between their lighter and darker areas are easier to see. Previous work has suggested that attention makes a visual stimulus easier to see by effectively increasing its contrast. However, contrast sensitivity decreases after prolonged periods of looking at high-contrast stimuli. Ling and Carrasco showed people black and white stripes, and had them report whether these stripes leaned to the left or the right; this task is harder to do when the contrast between the stripes is lower. The researchers found that when people paid attention to a particular set of stripes, they could initially do the task even with low-contrast stripes. However, after a prolonged period of attention, people needed higher-contrast stimuli to succeed at the same task. These results indicate that prolonged periods of attention to specific stimuli may eventually impair rather than improve perception.

Author contact:

Samuel Ling (New York University, NY, USA)
E-mail: ling@nyu.edu

Abstract available online.

Nature Neuroscience press release.

Message posted by: Trevor M. D'Souza