“Memory is not a single entity but consists of several separate entities that depend on different brain systems. The key distinction is between the capacity for conscious recollection of facts and events (declarative memory) and a heterogeneous collection of nonconscious learning capacities (nondeclarative memory) that are expressed through performance and that do not afford access to any conscious memory content.” (Squire and Zola, 1996)
“A taxonomy of long-term memory systems together with specific brain structures involved in each system.”