ASK A SCIENTIST
Question: Why do we dream?
Your amazing brain weighs about three pounds and has roughly 100 billion cells called neurons that communicate in a complex manner. They are responsible for your thoughts, actions, memories, feelings, and how you see and feel the world. Modern imaging helps us learn more every day, but there's a lot we don't know.
Each neuron is connected with thousands of others. They constantly form new connections, which is why it's important to keep mentally active. With so much going on, it's impossible to keep track of everything. You have a conscious brain that deals with information coming from your senses. The rest is called your subconscious brain where you process information you are not aware of.
When you think about something not coming from your senses, it's your unconscious brain talking. There a lot more subconscious thought than what you see in your conscious window. When you fall asleep, information from your senses is mostly turned off, but your neurons keep communicating. This is when the unconscious brain takes over, and it's where dreams come from.
When you first fall asleep, you enter deep sleep where not much dreaming occurs. After a few hours, you enter a stage of lighter sleep where your eyes move rapidly while they stay shut. This rapid eye movement sleep (REM sleep) features a lot more dreams. You average about two hours of dreams each night. Dreams usually last between five and twenty minutes. You don't remember about 95% of your dreams, but you remember the most vivid dreams, and dreams that are in progress when you wake up.
Dreams can be pleasant, weird, or scary. Scary dreams are called nightmares. Dreams are usually influenced by your recent activity, but they can deal with your distant past.
Scientists do not agree about weather dreams have any useful purpose, but for thousands of years, people have tried to analyze dreams, use them to predict the future, and communicate with the dead. There is no scientific support for this.
Sometimes dreamers know they are dreaming. This is called lucid dreaming. In lucid dreams you have some control. Consider starting a dream log by taking notes on dreams you remember. They might even contain solutions to problems you were trying to solve during the day. You to can join scientists as they try to expand our understanding of how the brain works. Welcome to the quest.
Ask a Scientist appears Thursdays. Questions are answered by faculty at Binghamton University. Teachers in the greater Binghamton area who wish to participate in the program are asked to write to Ask A Scientist, c/o Binghamton University, Office of Communications and Marketing, PO Box 6000, Binghamton, NY 13902-6000 or e-mail firstname.lastname@example.org. Check out the Ask a Scientist Web site at askascientist.binghamton.edu. To submit a question, download the submission form(.pdf, 460kb).