The idea of subliminal perception - that stimuli presented below the threshold for awareness can influence thoughts, feelings, or actions – is a fascinating and kind of creepy one. Can messages you are unaware of, embedded in movies or ads or the music playing in the grocery store, really influence what you buy? Many such claims of the power of subliminal perception have been made. One of the most famous came from a market researcher who claimed that the message “Eat Popcorn” briefly flashed throughout a movie increased popcorn sales by more than 50% although he later admitted that the study was made up (Merikle, 2000).
Psychologists have worked hard to investigate whether this is a valid phenomenon. Studying subliminal perception is more difficult than it might seem, because of the difficulty establishing what the threshold for consciousness is or of even determining what type of thresholds important; for example, Cheesman and Merikle (1984, 1986) make an important distinction between objective and subjective thresholds. The bottom line is that there is some evidence that individuals can be influenced by stimuli they are not aware of, but how complex stimuli can be or the extent to which unconscious material can affect behavior is not settled.