- The Default Mode Network (DMN) is a group of brain regions that show higher activity when the brain is at rest and not focused on the outside world.
- This network is primarily involved in self-referential thoughts, daydreaming, and mind-wandering.
- It becomes less active during tasks that require focused attention and external goal-directed behavior.

- During restful wakefulness, individuals are awake but not actively engaged in any specific task, allowing the DMN to be highly active.
- In contrast, when a person is engaged in goal-directed tasks (Option 1), the brain shifts activity away from the DMN toward task-positive networks involved in attention and problem-solving.
- In deep non-REM sleep (Option 2), brain activity patterns change significantly, and the DMN is not prominently active.
- Similarly, during REM sleep (Option 4), although there is increased brain activity, the pattern differs and the DMN is not the primary network active.

Therefore, the Default Mode Network is most active during restful wakefulness, when the brain is internally focused and not engaged in specific external tasks.