Josh McDermott continues his lecture on attention in MIT's course 9.35, Perception. He examines texture segregation, the way the visual system groups or separates regions based on patterns rather than raw input, and attentional selection in time, looking at phenomena where the brain fails to register items presented in close temporal succession. The throughline is that attention is not a neutral spotlight on the world but a mechanism with systematic limits, and McDermott works through experimental demonstrations showing where perception diverges from the actual sensory input. The seventy three minute session builds on a prior lecture, moving through specific paradigms researchers use to probe these failures and what they reveal about how selective processing shapes what we consciously perceive. It is a technical, example driven session aimed at students already following the course's treatment of perceptual mechanisms.