New findings clarify where and how the brain’s “slow waves” originate. These rhythmic signal pulses, which sweep through the brain during deep sleep at the rate of about one cycle per second, are assumed to play a role in processes such as consolidation of memory. For the first time, researchers have shown conclusively that slow waves start in the cerebral cortex, the part of the brain responsible for cognitive functions. They also found that such a wave can be set in motion by a tiny cluster of neurons.
