The origin of each of the major memory systems of the brain is the vast expanse of the cerebral cortex, in particular on the highest stages of the several distinct sensory and motor processing hierarchies — the cortical association areas. The cerebral cortex provides major inputs to each of three main pathways associated with distinct memory functions as shown in studies that employ double dissociation of their functions.

1. One pathway is to the hippocampus, which supports the relational memory and flexibility in memory expression.
2. Another major system involves the amygdala as a nodal stage in the association of exteroceptive sensory inputs to emotional outputs, which is essential for emotional memory.
3. The third system involves the neostriatum as a nodal stage in the association of sensory and motor cortical information with voluntary responses, and this pathway plays a critical role in habit memory or procedural memory.

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