We make our eye movements earlier or later in order to coordinate with movements of our arms, New York University (NYU), New York, neuroscientists have found. Their study, which appears in the journal Neuron, points to a mechanism in the brain that allows for this coordination and may have implications for rehabilitation and neuroprosthetic technology.
Such coordination is central to the way different systems of the brain communicate with each other, and these undertakings are complicated-due to differences in weight, for instance, the arm takes longer than the eye to move. A better understanding of these neurological processes may help address the needs of those who have suffered brain injuries and struggle to coordinate movements among different parts of the body. In addition, new insights in this area could lead to more advanced neuroprostheses.
In their study, the NYU researchers examined the neurological activity of macaque monkeys while the subjects performed a variety of tasks that required them to either reach and to simultaneously employ rapid eye movements or to only use rapid eye movements, also known as saccades. The resulting readings revealed 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. The patterns of firing were found in regions of the PPC that are specialized for moving either the eye or the arm. Coherent patterns of firing may be due to these different brain areas communicating when coordinating movement, the research team concluded.
However, the finding is only a step and additional study is likely to reveal a more complex process, said Bijan Pesaran, an assistant professor of neural science in NYU’s Center for Neuroscience and the study’s senior author.
In addition, their data showed a coordination 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,” Pesaran said. “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.”
