WHY THERE ARE COMPLEMENTARY LEARNING-SYSTEMS IN THE HIPPOCAMPUS AND NEOCORTEX - INSIGHTS FROM THE SUCCESSES AND FAILURES OF CONNECTIONIST MODELS OF LEARNING AND MEMORY

Damage to the hippocampal system disrupts recent memory but leaves rem ote memory intact: The account presented here suggests that memories a re first stored via synaptic changes in the hippocampal system, that t hese changes support reinstatement of recent memories in the neocortex , that neocortical synapses change a little on each reinstatement, and that remote memory is based on accumulated neocortical changes. Model s that learn via changes to connections help explain this organization . These models discover the structure in ensembles of items if learnin g of each item is gradual and interleaved with learning about other it ems. This suggests that the neocortex learns slowly to discover the st ructure in ensembles of experiences. The hippocampal system permits ra pid learning of new items without disrupting this structure, and reins tatement of new memories interleaves them with others to integrate the m into structured neocortical memory systems.