The Hidden World of Unconsciousness: Fainting, Alcohol Blackouts, and Coma Awareness
“Some people who appear completely unconscious may still be listening, understanding, and waiting for a way to respond.” — Dr. Vicki Draeger
The Hidden World of Unconsciousness: Fainting, Alcohol Blackouts, and Coma Awareness
Episode [10] · [June 12, 2026] · Blossoming Brains Podcast
Introduction:
What if someone who appears completely unconscious can still hear your voice?
The science of unconsciousness is revealing surprising truths about fainting, alcohol blackouts, memory loss, and coma awareness. In this episode, Dr. Vicki Draeger explores what happens when consciousness disappears—and what may remain active inside the brain when the outside world sees only silence.
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In this episode
What consciousness actually is and how it can disappear
Why fainting causes temporary loss of awareness
The dangerous truth about alcohol blackouts
How alcohol disrupts memory formation in the hippocampus
Why passing out from alcohol may increase dementia risk
New discoveries about hidden awareness in coma patients
Key takeaways
Consciousness depends on communication across large brain networks.
Fainting temporarily interrupts that communication.
Alcohol blackouts prevent memory storage even while a person appears awake.
Heavy alcohol-induced unconsciousness may have long-term neurological consequences.
Some coma patients retain awareness despite being unable to respond.
Familiar voices and shared memories may support recovery.
Resources mentioned
BrainFacts.org. (2016, September 13). The Three Causes of Fainting. Society for Neuroscience. Retrieved from https://www.brainfacts.org/brain-anatomy-and-function/body-systems/2016/the-three-causes-of-fainting
National Institute of Neurological Disorders and Stroke. (2024, July 19). Syncope. National Institutes of Health. Retrieved from https://www.ninds.nih.gov/health-information/disorders/syncope
Urban, K. (2018, February 22). The Unconscious Brain — Finding Clarity During Unconsciousness. Michigan Medicine Health Lab. Retrieved from https://www.michiganmedicine.org/health-lab/what-happens-brain-during-unconsciousness
White, A. M. (2003). What happened? Alcohol, memory blackouts, and the brain. Alcohol Research & Health, 27(2), 186–196. PMC6668891. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC6668891/
National Institute on Alcohol Abuse and Alcoholism. (2025, December). Alcohol and the Brain: An Overview. Retrieved from https://www.niaaa.nih.gov/publications/alcohol-and-brain-overview
Hermens, D. F., & Lagopoulos, J. (2018). Binge drinking and the young brain: A mini review of the neurobiological underpinnings of alcohol-induced blackout. Frontiers in Psychology, 9, 12. Retrieved from https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2018.00012/full
Washington University School of Medicine in St. Louis. (2011, July 6). The biology behind alcohol-induced blackouts. The Source. Retrieved from https://source.washu.edu/2011/07/the-biology-behind-alcoholinduced-blackouts/
Kivimäki, M., Singh-Manoux, A., Batty, G. D., Sabia, S., Sommerlad, A., Floud, S., … Strandberg, T. (2020). Association of Alcohol-Induced Loss of Consciousness and Overall Alcohol Consumption With Risk for Dementia. JAMA Network Open, 3(9), e2016084. doi:10.1001/jamanetworkopen.2020.16084. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC7489835/
Jain, S., & Iverson, L. M. (2023). Glasgow Coma Scale. In StatPearls. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK513298/
Brain & Life. (n.d.). What is the Difference Between Coma, Minimally Conscious State, and Persistent Vegetative State? American Academy of Neurology. Retrieved from https://www.brainandlife.org/articles/what-is-the-difference-between-coma-minimally-conscious-state-persistent
Columbia University Irving Medical Center. (2023, August 14). Source of Hidden Consciousness in 'Comatose' Brain Injury Patients Found. Retrieved from https://www.cuimc.columbia.edu/news/source-hidden-consciousness-comatose-brain-injury-patients-found
Bodien, Y. G., et al. (2024). Cognitive Motor Dissociation in Disorders of Consciousness. New England Journal of Medicine, 391(6), 598–608. As reported in: Harvard Gazette. (2024, August 21). International study detects consciousness in unresponsive patients. Retrieved from https://news.harvard.edu/gazette/story/2024/08/international-study-detects-consciousness-in-unresponsive-patients/
Paul, M. (2015, January 22). Family Voices and Stories Speed Coma Recovery. Northwestern Now, Northwestern University. Retrieved from https://news.northwestern.edu/stories/2015/01/family-voices-and-stories-speed-coma-recovery
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Episode transcript
Note: This summary was created from the episode transcript and highlights the main topics discussed.
What happens when consciousness disappears? In this episode of Blossoming Brains, Dr. Vicki Draeger explores the science of unconsciousness, from everyday fainting spells to alcohol-induced blackouts and the mysterious world of medical comas.
The episode begins by examining what consciousness is and how it depends on communication between different regions of the brain. Using the analogy of a city powered by oxygen-rich blood, Dr. Draeger explains how fainting occurs when blood flow to the brain briefly drops, causing a temporary loss of consciousness. She also discusses breath-holding spells in young children and the dangers of intentionally restricting oxygen to the brain through activities such as the "choking game" or "blackout challenge."
The discussion then turns to alcohol-induced unconsciousness and blackouts. Listeners learn how alcohol disrupts the hippocampus, the brain structure responsible for forming new long-term memories. The episode explains the difference between fragmentary blackouts and complete memory blackouts and reviews research linking alcohol-induced loss of consciousness to an increased risk of dementia later in life. Special attention is given to the vulnerability of the adolescent brain and the long-term consequences of heavy drinking during critical periods of brain development.
The final section explores medical comas and recent discoveries that are changing how scientists understand consciousness. Dr. Draeger explains the differences between coma, vegetative states, and minimally conscious states before discussing groundbreaking research showing that some patients who appear completely unresponsive may still possess hidden awareness. Studies using advanced brain imaging techniques suggest that as many as one in four behaviorally unresponsive patients may be consciously processing information despite being unable to respond physically.
The episode concludes with research demonstrating the power of familiar voices and personal stories in supporting recovery. Studies have found that recordings from loved ones can activate memory and language networks in some coma patients and may help promote recovery of consciousness.
Throughout the episode, Dr. Draeger emphasizes both the remarkable resilience and the fragility of the human brain, encouraging listeners to protect their brain health, stay informed, and appreciate the extraordinary complexity of consciousness.
About the host
Dr. Vicki Draeger is a science educator, author, and mother of five whose work focuses on lifelong learning, neuroscience, and how the brain changes at every age. Named one of Hawaii’s top science teachers and a finalist for the U.S. Department of Energy’s Albert Einstein Distinguished Educator Fellowship, she now hosts Blossoming Brains to explore how minds—from human children to octopuses—learn, adapt, and thrive.
