induced wanting”: an external trigger causes a compulsive craving to repeat a bad habit. Once you notice something, you begin to want it. This process is happening all the time—often without us realizing it. Scientists have found that showing addicts a picture of cocaine for just thirty-three milliseconds stimulates the reward pathway in the brain and sparks desire. This speed is too fast for the brain to consciously register—the addicts couldn’t even tell you what they had seen—but they craved the drug all the same.

