Pareidolia

Pareidolia (/pærᵻˈdoʊliə/ parr-i-DOH-lee-ə) is a psychological phenomenon involving a stimulus (an image or a sound) wherein the mind perceives a familiar pattern of something where none actually exists.

Common examples are perceived images of animals, faces, or objects in cloud formations, the man in the moon, the moon rabbit, and hidden messages within recorded music played in reverse or at higher- or lower-than-normal speeds.

The word is derived from the Greek words (παρά, "beside, alongside, instead [of]", in this context meaning something faulty or wrong) and the noun (εἴδωλον "image, form, shape", the diminutive of eidos).

Pareidolia can cause people to interpret random images, or patterns of light and shadow, as faces. A 2009 magnetoencephalography study found that objects perceived as faces evoke an early (165 ms) activation of the fusiform face area at a time and location similar to that evoked by faces — whereas other common objects do not evoke such activation. This activation is similar to a slightly faster time (130 ms) that is seen for images of real faces. The authors suggest that face perception evoked by face-like objects is a relatively early process, and not a late cognitive reinterpretation phenomenon. An fMRI study in 2011 similarly showed that repeated presentation of novel visual shapes that were interpreted as meaningful led to decreased fMRI responses for real objects. These results indicate that the interpretation of ambiguous stimuli depends upon processes similar to those elicited by known objects.

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