Artificial intelligence can now produce acclaimed essays and support medical diagnoses with impressive precision, yet biological brains still outperform machines in one essential area: flexibility. Humans can absorb new information and adapt to unfamiliar situations with very little effort. People can jump into new software, follow a recipe they have never tried before, or learn the rules of a game they have just discovered, while AI systems often struggle to adjust in real time and to learn effectively “on the fly.”

A new study from Princeton neuroscientists offers insight into why the brain excels at this kind of rapid adjustment. The researchers found that the brain repeatedly draws on the same cognitive “blocks” when performing different types of tasks. By recombining these blocks in new ways, the brain can quickly generate fresh behaviors.