Mental imagery is related to our perception of the external world, according to a new study of how the brain processes images.

Joel Pearson of the University of New South Wales and colleagues asked participants to imagine a green circle with vertical lines or a red circle with horizontal lines, and rate how vivid the mental image was and how difficult it was to conjure. They then presented the subjects with a binocular rivalry display, where the left and right eyes each see a different pattern, and asked them to report which pattern their brain settled on as dominant.

The researchers found that the pattern that participants reported as being most vivid when imagined was the same as the one that dominated in binocular rivalry. They suggest that this supports the idea that internal mental images are closely related to how brains perceive the external world.

Ref.: Psychological Science