The early catches the worm. This means people who wake up early do things. This may be . Scientists found that who sleep early do in . People who sleep and wake up early (early birds) do than people who sleep and wake up (night owls). brains are .
The tested 38 people. They answered about sleep and . They had scans and did tests. The early were less . They did the tests than the night owls. The scientists said night owls have to get up for and work. They want to sleep late.