Human brain may know which eye is receiving information and can turn around and tell the eye to work even harder, suggests study.
"We have demonstrated for the first time that you can pay attention through one eye, even when you have no idea where the image is coming from," said Peng Zhang, who conducted the study with University of Minnesota colleagues Yi Jiang and Sheng He.
And the harder that eye is working-the heavier the "informational load"-the more effectively still that eye can attend to its object.
The researchers conducted two experiments, each with six observers ages 20 to 29, who viewed images through a mechanism that can separate stimuli by eye.
The viewers took less time to notice the emerging target when it was in the same eye as the cue.
In the second experiment, the task was harder. Two cues were displayed at once and participants had to attend to both or to two "features" at once-indicating for instance when both were red or both red and thick.
Again, the target appeared even faster when the cues were in the target eye and even slower when they were in the noise eye.
The findings, said Zhang, suggest some intriguing things about the visual system.
"Maybe there are binocular neurons in the brain"-neurons that take in and collate information from both eyes-"that also know which eye that information is coming from and can feed back to that eye," telling it to pay closer attention.
In other words, the mechanisms of visual perception, and the communications between eye and brain, may be even more flexible and powerful than scientists thought.
The findings will appear in an upcoming issue of Psychological Science, a journal published by the Association for Psychological Science.