Are stimuli screened out early, during sensory input, or late, after the brain has processed it. Storage: involves maintaining encoded information in memory over time. You generally need to pay attention to information if you intend to remember it. Attention: involves focusing awareness on a narrowed range of stimuli or events. Attention is like a filter that screens out most potential stimuli while allowing a select few to pass through into conscious awareness. The cocktail party effect suggests it is after the brain has processed it. Studies have found evidence for both as well as for intermediate selection. It is clear that people have difficulty if they attempt to focus their attention on two or more inputs simultaneously. When people multitask, they are really switching their attention back and forth amongst tasks, rather than processing them simultaneously. Differences in how people attend to info are the main factors influencing how much they remember.