How are memories formed and stored in the brain?

The answer

Memory formation begins in the hippocampus, where new experiences trigger a process called long-term potentiation (LTP), in which repeated stimulation of synapses strengthens the connections between neurons. Short-term memories are initially encoded in the hippocampus and then gradually consolidated into long-term storage distributed across the neocortex during sleep, a process called systems consolidation that can take weeks or years. Different aspects of a single memory are stored in different brain regions: the visual cortex stores the visual components, the auditory cortex stores sounds, and the amygdala encodes the emotional significance. Recalling a memory involves reactivating this distributed network, and each retrieval actually makes the memory temporarily malleable, allowing it to be updated before being restabilized through a process called reconsolidation.