Better understanding of rehabilitation and prosthetics through eye-arm co-ordination
Neuroscientists at New York University have found that we move our eyes earlier or later according to our arm movements.
A study published in the journal Neuron suggests this co-ordination is controlled by a brain mechanism
and could affect rehabilitation and prosthetics.
Researchers have long sought to understand what happens in our brains to sync our eyes and arms when we reach for objects. This coordination is vital to how brain systems communicate and is governed by many factors (for example, weight differences mean arms take longer to move than eyes).
A better comprehension of such neurological processes
is vital to rehabilitation and could help those with brain injury who cannot properly co-ordinate movements of different parts of the body.
New insights could also prompt advances in neural prosthetics: the artificial body extensions that aid functions of the nervous system lost during disease or injury
Due to comparatively limited knowledge of how the brain co-ordinates movement, these devices are currently unrefined.
The NYU researchers examined neurological activity in macaque monkeys performing tasks that required them to either reach and simultaneously employ rapid eye movements, or to use rapid eye movements (or saccades) alone.
Findings showed significant coherent patterns of firing of neurons in the brain's posterior parietal cortex (PPC)
when both the eyes and arms were required to move for the same task, but not for tasks that involved only saccades. Firing patterns were found in PPC regions that specialise in moving the eye and the arm.
The research team concluded that coherent firing patterns may be because of these different brain areas communicating when co-ordinating movement.
Prof Bijan Pesaran, the study's lead author, said: "We think we have a mechanism for co-ordination."
Adding that additional study is likely to reveal more complex processes, Prof Pesaran continued: "Our findings show it is the patterns of activity in a specific region of the brain just prior to both saccades and reaching that are important."
The study team's data also demonstrated a co-ordination of movement between the eyes and arms.
"The brain adjusts timing of eye movements, depending on how long it takes to start moving the arm," concluded Prof Pesaran. "Our study is asking how information flows between the arm and eye movement systems, and it shows how coherent patterns of neural activity are important to this communication."Useful links