Subliminal Priming

Subliminal priming refers to the finding that a stimulus presented so briefly, faintly, or otherwise degraded that a person cannot consciously perceive or report it can nonetheless measurably influence that person's subsequent thoughts, judgments, or reaction times to a related, consciously presented stimulus. In controlled laboratory demonstrations, researchers typically use techniques such as very brief exposure followed immediately by a masking pattern to ensure the priming stimulus genuinely falls below the threshold of conscious awareness, then measure whether it speeds up or otherwise affects performance on a task involving a related word or image presented afterward. The idea of subliminal influence entered popular culture largely through a widely publicized but later discredited 1957 claim of subliminal advertising success in a movie theater, which its own promoter eventually admitted had been fabricated, a hoax episode that is frequently distinguished in the academic literature from the smaller, carefully measured effects that legitimate subliminal priming research has subsequently documented under tightly controlled experimental conditions. Contemporary research supports the existence of genuine, if generally modest and short-lived, subliminal priming effects on simple perceptual and cognitive tasks, but has found much weaker and less consistent support for the far more dramatic claims once made about subliminal messages being able to covertly control complex real-world decisions such as purchasing behavior.