The current protocol will utilize a paradigm which is well suited to examine frontal attentional neuronal mechanisms by eliciting event related potential components known to reflect automatic stimulus detection as well as involuntary and voluntary attentional processes. The that end the proposed research has two specific aims. 1) Identify what areas of the frontal lobe and corresponding cognitive functions are impacted by excessive sleepiness in shift work sleep disorder and 2) identify specific brain areas affected by armodafinil and their role in improvement of fundamental attentional processes using a complex cognitive task targeting attentional control.