Ross School - Senior Project 2008-09

Student: YiYing Zhu

Mentor: Dr. Costello

Title: On the Neurological State of Dreaming and Sleeping


For my Senior Project I tested the hypothesis of whether or not our brain returns to an "ancestral state" during slumber. For my final product I created a poster about the answer to this theory. The reason I chose my topic was because I am very interested in how the brain functions during slumber. I have learned that sleep is necessary for memory processing, so therefore, I will use the knowledge I gained from my Senior Project in the following way: since sleep is good the body, I will sleep more in the future.


I presented my research and discoveries in the form of a poster.

Final Poster

For my senior project, I came up with an original scientific hypothesis and tested it through literature review. I presented my research and ideas in the form of a poster.

I chose neuroscience for my senior project during 11th grade. I did some research during the summer. I became very interested in visual perception. As my knowledge expanded my interest broaden in this field. Instead of just focusing on vision, I created a hypothesis that involves dreaming, sleeping, hallucination and blindness.

My hypothesis is that the human brain will return to an “ancestral state” when we sleep or dream. In the “ancestral state,” only the mammalian brain (the limbic system) is active, while the rest of the human brain “shuts down” or becomes less functional. This brain state is very similar to an undeveloped brain. There are similarities and differences in mental states when humans are conscious and when they are unconscious. A conscious mental state is when humans are awake; the unconscious refers to the mental state during dreaming and sleeping. The mental state of an unconscious brain turns out to be more complex than an undeveloped brain. Emotions, memory, daily experiences, and unconscious cognition all play important roles during sleep.

Before, compositing everything together to make the poster, I decided to write a paper as an intermediate step. I wanted to organize all my research and knowledge I learned together. My paper is about 7-8 pages. I got feedbacks from my mentor and outside consultants. I contacted with two of my outside consultants, Dr. Pamela Lein and Dr. Todd Rose through e-mail. Dr. Kurt Fisher actually came to the Ross campus once to meet with me face to face. Thanks to all of them, I cleared out many mistakes and also learned a lot of knowledge.

In conclusion, during sleep, many parts of the brain, such as the limbic system, work in similar ways as when we are conscious. However, this is not the only part of the brain that is functioning. Many parts of the brain, such as the cerebrum, do not “shut down” at all, but merely work differently than when we are conscious. Part of the cerebral cortex that registers emotions is still effective, while other parts of the cortex are engaged mainly in memory processing. Nevertheless, the limbic system, a more ancestral part of our brain, is rather prevalent when we sleep. During sleep, functions of the mammalian brain are heightened, and the cortex turns to an unconscious state, mainly devoted to unconscious cognition. The fundamental and biochemical mechanisms underlying unconscious cognition still remain unclear. These questions need to be further investigated.

Throughout the course of my senior project, my research and writing skills improved a lot. This is the first serious research project I have ever done in my whole academic career. This project prepared me for my future. I am probably going to pursue in the field of neuroscience in the near future.

Works Cited

Andreasen, N.C. 2005. The Creating Brain. New York (NY): Dana Press  p. 18-23.

Blakeslee, S. 1993. Seeing and Imagining: Clues to the Workings of the Mind’s Eye. Wade, N. The New York Times Book of The Brian. Guilford (CT): The Globe Pequot Press. p. 19-24.

Blakeslee, S. 1994. Clues to the Irrational Nature of Dreams. Wade, N. The New York Times Book of The Brian. Guilford (CT): The Globe Pequot Press. p. 226-231.

Bower, B. 1990. A Thoughtful Angle on Dreaming. Science News 137(22): 348

Carter, R. 1998. Mapping the Mind. (CA):University of California Press . p. 16-17, 32-33, 82, 161, 194.

Fong, L. 2006. It’s Not All in the Eyes. Seed [Internet]. [cited 2008 December 16]; 10:10. Available from:

Gibson, J.J. On the Relation Between Hallucination and Perception [Internet]. Leonardo. Pergamon Press; 1970 [cited 2008 December 15]. Available from:

Gray, Peter. 2007. Psychology. (NY): Worth Publishers. p. 201-209

 Hobson, J. Allan, Pace-Schott, E. and Stickgold, R. (2000), DREAMING and the BRAIN: Toward a Cognitive Neuroscience of Conscious States, Behavioral and Brain Sciences 23 (6)

Hurovitz, C., Dunn, S., Domhoff, G. W., Fiss, H. 1999. The dreams of blind men and women: A replication and extension of previous findings. Dreaming, 9, 183-193.

Kerr, N., Domhoff, G.W. 2004. Do the Blind Literally “See” in Their Dreams? A critique of a recent claim that they do. Dreaming, 14, 230-233

Miejan, J. 1998. The EDGE Interview with Bill Harris of Centerpointe Research Institute. Trans4mind [Internet]. [cited 2008 December 16]; 9:53. Available from:

Ramachandran, V.S., Ramachandran, D.R. 2008. I See, But I Don’t Know. Scientific American Mind 19(6):20-22.

Stickgold R., Ellenbogen, J.M. 2008. Quiet! Sleeping Brain at Work. Scientific American Mind 19(4): 23-29.

Swaminathan, N. 2005. Disconnections During Sleep. Seed [Internet]. [cited 2008 December 16]; 10:13. Available from:

Watakabe, A. 2007. What is Neocortex? BraInSitu [Internet]. [cited 2008 December 16]; 9:19. Available from:

Welker, W., Johnson, J.I., Noe, A. Comparative Mammalian Brain Collections. Major National Resources For Study of Brain Anatomy [Internet]. [cited 2008 December 16]; 9:40. Available from:

Community Member (Details)

Dr. Pamela Lein—Scientist at Oregon Health and Science University

Dr. Todd Rose—Research scientist at Harvard

Dr. Kurt Fisher—Director of the Mind Brain Education