Modern materialistic science is not sure about the origin and nature of most psychic phenomena including dreams. This information can be found in Vedic scriptures.
Srimad Bhagavatam 6.16.53-54, 7.7.25 or 7.15.61 describes three material states of consciousness:
1. jagrata, awakened state (beta, 14 – 20 Hz)
2. svapna, dreaming state (alfa, 7 – 14 Hz)
3. susupti, deep sleep (theta, 4 – 7 Hz)
Beyond them is the fourth state (turya) which is non-material (SB 6.5.12, 7.9.32, 7,15.54). On this level
