Chapter 5: Variations in Consciousness On the Nature of Consciousness Awareness of Internal and External Stimuli Variations on levels of awareness James ? stream of consciousness Freud ? unconscious Sleep/dreaming research The Electroencephalograph: A Physiological Index of Consciousness EEG ? monitoring of brain electrical activity Brain-waves Amplitude (height) Frequency (cycles per second) Beta (13-24 cps) Alpha (8-12 cps) Theta (4-7 cps) Delta (<4 cps) Table 5.1 EEG Patterns Associated with States of Consciousness Biological Rhythms and Sleep Circadian Rhythms ? 24 hr biological cycles Regulation of sleep/other body functions Physiological pathway of the biological clock: