Evidence for an active handoff between hemispheres during target tracking

The brain has somewhat separate cognitive resources for the left and right sides of our visual field. Despite this lateralization, we have a smooth and unified perception of our environment. This raises the question of how the cerebral hemispheres are coordinated to transfer information between them. We recorded neural activity in the lateral prefrontal cortex, bilaterally, as two male non-human primates covertly tracked a target that moved from one visual hemifield (i.e., from one hemisphere) to the other. Beta (15–30 Hz) power, gamma (30–80 Hz) power, and spiking information reflected sensory processing of the target. By contrast, alpha (10–15 Hz) power, theta (4–10 Hz) power, and spiking information seemed to reflect an active handoff of attention as target information was transferred between hemispheres. Specifically, alpha power and spiking information ramped up in anticipation of the hemifield cross. Theta power peaked after the cross, signaling its completion. Our results support an active hand-off of information between hemispheres. This “handshaking” operation may be critical for minimizing information loss, much like how mobile towers handshake when transferring calls between them. Significance Statement Multiple neurological disorders have reduced functional connectivity between the cerebral hemispheres, impacting interhemispheric communication. We characterized neural activity in the prefrontal cortex as information was transferred from one hemisphere to the other. We found neural signatures that both anticipated this information transfer and registered its completion. These signatures may prevent information loss and allow for a smooth perception of our visual field.