The average person has about 48.6 thoughts per minute, according to the Laboratory of Neuro Imaging at the University of Southern California. That adds up to a total of 70,000 thoughts per day.
The average human brain weighs about 3 pounds and continues to grow from conception until the person is about 18 years old. Human brains contain around 100 billion cells, which can live for an entire human lifetime, making them frequently the oldest living cells in the human body. The left side of the human brain has considerably more neurons than the right side, and the forebrain, which controls intellectual function, is far larger in humans than in other animal species.
The thoughts in a human brain are powered by neurotransmitters, which in turn are powered by copious quantities of blood flowing through the brain every minute. The brain can only survive without oxygenated blood for 4 to 6 minutes. After that time, brain cells begin to die off. A person will lose consciousness after only about 10 seconds without oxygenated blood, however. Although the brain continues to process thoughts while its owner is asleep, different neurotransmitters control sleeping brain thoughts, which is why dreams can seem so different from waking thoughts.