Consciousness

[Alan V]

Unconsciousness cannot cause consciousness.

Our brainstems turn on and off our consciousness through the cycles of waking, sleeping, and dreaming.  This process depends on both neuromodulation and activation or deactivation.  Yet the brainstem is not conscious itself.

Per Google:

While the brainstem is crucial for wakefulness and basic life functions, it's not considered the seat of consciousness in the way the cerebral cortex is. The brainstem plays a role in consciousness, particularly in wakefulness and arousal, but complex conscious experiences are thought to arise from the interaction of the brainstem with other brain regions like the cerebral cortex and thalamus.
...
Lesions in specific areas of the brainstem, like the rostral dorsolateral pontine tegmentum, can lead to coma, further highlighting the brainstem's role in maintaining wakefulness and its connection to overall consciousness, according to Harvard Medical School.