VATH: Vigilance Across the Hemifields

The corpus callosum is a major facilitator in hemispheric communication. When disrupted, via a corpus callosotomy, the two hemispheres function independently with minimal information exchanged. This disruption can give insight into the roles of each hemisphere when presented with lateralized stimuli. We developed a lateralized version of the Continuous Temporal Expectancy Task (LCTET) to investigate a difference in vigilance between the hemispheres. We conducted a pilot study (n=12) to validate the task in controls. Subjects were instructed to respond to long-duration images (10% of trials) with their left or right hand. Images were shown on either the center, left, right, or both left and right sides of the screen. We hypothesize that while centralized and peripheral images may be processed differently, this may not impact sustained attention. The results indicate that even though the detection rate was worse for left and right conditions compared to center, the vigilance decrement was apparent for these three conditions. This study has validated that a vigilance decrement is seen with an LCTET and people can perform the task comparably to the centralized version. Our next steps will be to perform a control study and soon administer the LCTET to split-brain patients to investigate the impact of a sustained attention task within the isolated hemispheres.

Project Mentor: Henri Etel Skinner

Faculty Mentor: Michael Miller