Here's the latest Narco Polo comic by Rob Arthur, a a former inner-city teacher and public defender and author of one of my favorite books, You Will Die: The Burden of Modern Taboos.
The astronomer and author, Carl Sagan, attributed numerous insights to marijuana and has defended this inspiration from those who call it illusory. (5) To read his entire treatise on the cerebral benefits of marijuana use go to this link.
The psychologist, Susan Blackmore, has written, "I can honestly say that without cannabis, most of my scientific research would never have been done and most of my books on psychology and evolution would not have been written." (1)
One way in which creativity can be described is the ability to find new and novel connections between concepts. In scientific terms the ability to find connections between words is called semantic priming. A 2010 study published in Psychiatry Research found that the use of marijuana induces a state of hyper-priming. (9) When presented with an activation word, subjects reacted faster to distantly-related words when high than when sober. (For a neuroscience journalist's take on this study go here.) The flow of loose associations promoted by marijuana is a real phenomenon.