Hippocampal ripples and replay reveal how brain recombines past knowledge for flexible planning

When facing new situations or problems, humans typically rely on knowledge they acquired in the past. Specifically, neuroscience studies suggest that the brain reorganizes past experiences and previously acquired knowledge, creating mental frameworks that can help humans to solve the problems they are facing. The recombination of past knowledge into new mental structures also allows humans to flexibly plan future actions in changing environments. Past studies suggest that two key brain regions contribute to this process, the hippocampus and the medial prefrontal cortex (mPFC).