It turns out that dopamine is a chemical on double duty in the brain. Along with its role in motor commands, it also serves as the main messenger in the reward systems, guiding a person toward food, drink, mates, and all things useful for survival. Because of its role in the reward system, imbalances in dopamine can trigger gambling, overeating, and drug addiction - behaviors that result from a reward system gone awry.
David EaglemanGiven the billions of neurons, this means there are as many connections in a single cubic centimeter of brain tissue as there are stars in the Milky Way galaxy.
David EaglemanEven while it's true that we are tied to our molecules and proteins and neurons - as strokes and hormones and drugs and microorganisms indisputably tell us - it does not logically follow that humans are best described only as pieces and parts.
David EaglemanKeep in mind that every single generation before us has worked under the assumption that they possessed all the major tools for understanding the universe, and they were all wrong, without exception.
David EaglemanReductionism is not the right viewpoint for everything, and it certainly won't explain the relationship between the brain and the mind. This is because of a feature known as emergence. When you put together large numbers of pieces and parts, the whole can become something greater than the sum.
David EaglemanIf you have certain problems with your brain but are raised in a good home, you might turn out okay. If your brain is fine and your home is terrible, you might still turn out fine. But if you have mild brain damage and end up with a bad home life, you're tossing the dice for a very unlucky synergy.
David Eagleman