A night owl — or an evening person with a late sleep-wake cycle — could be at a higher risk of cognitive decline with age compared to an early bird or a morning person, a study has found.

Chronotype refers to one's sleep-wake type or times during the day when one naturally tends to be awake and asleep. A 'night owl' chronotype is said to have a later sleep-wake cycle, compared to an 'early bird' or a 'lark'.

"Are you an early bird or a night owl? It's hard to adjust what your biological clock — your so-called chronotype — is, but you can adjust your life to it as best you can," study author Ana Wenzler, from the University Medical Center Groningen, the Netherlands, said.