The document discusses theories of short-term memory (STM) structure and capacity. It describes both multi-store models which view STM and long-term memory (LTM) as separate systems, and unitary-store models which view STM as activated representations in LTM. Evidence is presented supporting both views, with newer evidence favoring unitary-store models and an STM capacity of approximately 4 items that can be maintained through focused attention. Frontal cortex is believed to support executive attention processes rather than memory storage.

1. The Mind and Brain of Short-Term Memory John Jonides, Richard L. Lewis, Derek Evan Nee, Cindy A. Lustig, Marc G. Berman, and Katherine Sledge Moore Annual Review of Psychology