Neuronal firing patterns, illustration. In a study of epilepsy patients, researchers at the US National Institutes of Health (NIH) found that human brains may store memories in neuronal firing patterns that are replayed just before remembering past experiences. They monitored the electrical activity of thousands of brain cells (neurons) in patients as word memory tests were conducted. They discovered these distinct sequences of neural spiking activity in the anterior temporal lobe during learning and the formation of memories. Studies into how we form and retrieve memories help scientists understand brain function, and how memory disorders can be caused through the breakdown of neuronal circuits.