The purpose of flashbang grenades is to elicit varying degrees of psychological and physiological distress from a human target while minimizing the risk of significant injury to the human. The Institute for Defense Analyses (IDA) was tasked with examining the interaction of physiological and psychological responses to flashbang grenades in order to understand the processes driving measurable performance outcomes after exposure to a flashbang. This report provides a detailed path analysis of human responses to flashbangs, their relationship with performance outcomes, and their implications for the design of human subject experiments to quantify these effects. IDA used path analysis to identify what happens physiologically and psychologically between the deployment of a flashbang grenade and subsequent behavior change in the individual being subjected to the flashbang. Particular emphasis was placed on identifying relationships between immediate physiological effects such as eyeblink, intermediate psychophysiological effects such as distraction, and final measurable performance outcomes such as target detection and tracking accuracy, and targeting speed. The analyses were based on published studies of experiments with human subjects as well as those based on models of non-human organisms, mainly rodents. Five immediate effects were identified as the starting point of the analyses overpressure effects, hearing effects, the startle effect, StartReact (a cuing response that might enhance the performance of a planned motor action) and vision effectseach corresponding with unique physiological effects on the human body. For each immediate effect, we traced a path between the first physiological reaction and intermediate psychophysiological states such as distraction, disorientation and dizziness. The path from intermediate psychophysiological effects and final performance outcomes were then identified.