1961: American psychologist B. F. Skinner published his highly acclaimed book Walden Two. In it, Skinner advanced the theory of "behaviorism," which rejects the unobservable and the unconscious in favor of actual responses to actual events.

1966: French writer and so-called founder of surrealism Andre Breton died at the age of 70. Breton wrote three manifestos on surrealism and opened a studio for "surrealistic research."

1989: Spanish painter Salvador Dali died at the age of 85. Dali was a leader in surrealist visual art, using a precise style that enhanced the dreamlike effect of his work.

1990: President George Bush and the 101st Congress declared the 1990s to be the "Decade of the Brain." Throughout the decade, scientific information and research about the brain has amassed at an enormous rate, thanks mostly to technological advances in computer imaging and brain mapping.