Chapter 9 describes the integrated system model of perception, attention, visual working memory (VWM), and decision making, which characterizes performance in perceptual tasks that use brief, backwardly masked stimuli. Decisions in these tasks take longer to make than the time during which the stimulus is physically present. After an initial, time-varying, period of stimulus encoding, the evidence entering the decision process appears not to decay after the stimulus is masked, although the decision process is not yet complete. The lack of decay implies that the decision process is driven by stable representations in VWM and not by the decaying perceptual trace. The integrated system model assumes that drift and diffusion rates depend on a time-varying VWM trace that is formed under the control of attention. The chapter describes fits of the integrated system model to data from these kinds of tasks. The second part of the chapter describes two related models for decisions about stimuli presented in dynamic noise: the time-changed diffusion model and the release from inhibition model. The models capture the large changes in response time distributions produced by these stimuli.