The theory of dreaming proposes that dreaming occurs when the cerebral cortex synthesizes neural signals generated from activity in the lower part of the brain. activation-synthesis cognitive manifest content latent reasoning

The answer activation-synthesis. The theory is pegged on the high brain activity in the brain stem during deep sleep (rapid-eye-movement phase). The activity in this region is different during sleep and wake states. According to the theory, the primary consciousness is activated,
and expanded into secondary consciousness, during dreaming, while the body is an atonic state.