Top-Down Executive Control in Traumatic Brain Injury (TBI), PTSD and Combined

Traumatic brain injury (TBI) and PTSD both are characterized by deficits in attention, yet it is unclear as to whether this is related to an inability to focus on relevant information or ignore non-relevant information. History of TBI and PTSD are common to returning soldiers from OEF/OIF and thus is highly relevant to veteran health care. It is unclear how TBI and PTSD separately, and together, affect one's ability to focus attention versus inhibit distracting stimuli. This research investigates this issue by use of a working memory paradigm with functional magnetic resonance imaging (fMRI) that entails the subject being instructed to ignore some stimuli and remember other stimuli resulting in discrete biomarkers of (1) task-related enhancement of neural processes as well as (2) suppression of task-irrelevant neural processes. In this way, the specific aspect of attention in TBI and PTSD will be elucidated in addition to exploring whether PTSD and TBI have an additive, or even synergist, effect when combined.