Figure 1. Associative memory cells and their connections.

Top includes three groups of primary associative memory cells (green, red and blue) in the sensory cortices. There are mutual innervations among associative memory cells in each group (intramodal) and among three groups of associative memory cells (cross-modal). Bottom demonstrates secondary associative memory cells (orange) in cognition- and emotion-related brain area, and where these cells are mutually innervated. The axons of primary associative memory cells project to secondary associative memory cells whose axons project back to primary associative memory cells. All of neurons possess innate synapse innervations (yellow axons).