The brain has a special mechanism for integrating movement and vision, says new research from University College London (UCL) and Cambridge University. The researchers found evidence that a dedicated information ‘highway’ links spatial awareness of one’s own movements with visual input regarding body motion. The findings contribute to the body of knowledge regarding sensory processing.
Fifty-two healthy adults participated in three experiments for this study. In each experiment, the participants used robotic arms to control cursors on a computer display. The participants fixed their gaze on the screen’s center (confirmed through eye-tracking) while their hand motions were linked to cursor movement.
In the first experiment, participants controlled a cursor with each hand. The goal of this task was to guide each cursor from the center of the screen to a target at the top. This was made difficult by periodic ‘jumps’ of the cursor to the left or right; these jumps were occasionally signaled by a flash on the side of the screen. The second test was nearly the same as the first, but the researchers introduced changes in brightness to observe its effect on visual perception. In the third and final task, the researchers tested the participants’ abilities to deal with distractions. The participants guided a cursor to a target amid four decoy cursors and targets.
The results from all three experiments suggest that there is a mechanism in the brain that can visually track our bodies even when we are not paying attention. This ‘visuomotor binding’ mechanism is less affected by distractions than other visual processing regions of the brain.
“… We react very quickly to changes relating to objects directly under our own control, even when we are not paying attention to them” explains Dr. Alexandra Reichenbach of UCL’s Institute of Cognitive Neuroscience, lead study author. “This provides strong evidence for a dedicated neural pathway linking motor control to visual information, independently of the standard visual systems that are dependent on attention.
This research is published in the journal Current Biology.
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