Why do we sometimes wake up a few minutes before our alarm rings?


When you wake up at the same time every day, your brain learns.

When you wake up at the same time every day, your brain learns.
| Photo Credit: Solving Healthcare/Unsplash

— Dev

The human body has a built-in timekeeping system called the circadian rhythm. It is governed by a group of cells in the brain, centred on the suprachiasmatic nucleus, which uses signals such as daylight to keep the body’s roughly 24-hour cycle aligned with the outside world.

When you wake up at the same time every day, your brain learns. In the hours before your usual waking time, the body slowly prepares for wakefulness: e.g. levels of the stress hormone begin to rise and body temperature increases. Over time, these changes can help you wake naturally when you expect to.

But this process is not precise. If you wake at 6:57 am when your alarm is set for 7 am, it could be your circadian system doing its job. But if you wake at 6:59 once, it could just be coincidence. We tend to remember the uncanny ‘successes’, like waking seconds before the alarm, and forget the mornings when we woke at 5:43 for no apparent reason.

The phenomenon is thus neither pure coincidence nor pure foresight.

  • Related Posts

    How scientists are using menstrual blood to treat osteoarthritis

    For most of history, menstrual blood has been dismissed as biological waste. But emerging research is now recasting this material as a goldmine for non-invasive diagnostics and regenerative medicine. Its…

    Continue reading
    Nepal flash floods wash away illusions of clean, easy hydropower

    The wake of the August 26 flash floods in Nepal, which devastated several towns and villages, killed more than a thousand people, and left several more unaccounted for, follows a…

    Continue reading