In 1957 the pioneering work of Brenda Milner and her colleagues revealed that certain forms of long-term memory are acquired and encoded by the hippocampus and other regions of the medial temporal lobe, brain structures that are required for conscious awareness. It soon emerged that the brain is capable of forming two major types of memory: explicit (declarative) memory, for facts and events, people, places, and objects; and implicit (nondeclarative) memory, for perceptual and motor skills.
