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Biology

The Reticular Activating System and Its Role in Attention and Arousal

Quick fact

The reticular activating system is a tiny web of neurons, roughly the size of a pinky finger, housed deep in the brainstem, yet it helps control your entire level of wakefulness and focus.

Why this is interesting

Have you ever been able to sleep through loud noises but wake instantly when someone whispers your name? That’s your brain’s reticular activating system making split-second decisions about what matters.