A new study explains a possible reason why sometimes taking a nap break helps people perform better when they resume a task -- during sleep, short-term information related to the task at hand is converted into long-term, stronger memory, researchers found.

The team, led by researchers from Harvard Medical School, US, monitored brain activity of 25 participants as they were learning a typing sequence, followed by taking a nap.

During sleep, areas in the cortex -- brain's outermost layer that helps with higher-level functions such as memory -- that were active while the participants worked showed more rhythmic, repetitive patterns, indicating that information related to the task is being processed, the team found.