Media multitasking is a near-ubiquitous behavior in the modern world. Media multitasking has been associated with deficits in cognitive processing, but inconsistent and conflicting findings in this area point to the need for theoretical and operational clarity. This chapter outlines a neurophysiological approach to media multitasking research. First, it highlights brain networks that enable focused attention, distraction, and task switching. Second, it discusses how unique characteristics of digital media facilitate certain patterns of multitasking. Finally, three neurophysiological dimensions of media multitasking are outlined, providing a baseline for considering the relationship between multitasking behavior and potentially suboptimal cognitive outcomes.