IT TAKES A CONFOUNDED FACE TO POP OUT OF A CROWD

It is widely reported that a picture of an angry face seems to figurat ively pop out of an array of happy faces, although all of these report s are based on a single experiment by Hansen and Hansen. Pop out, when it occurs, indicates that an observer has located the target by means of a preattentive, parallel search. Hansen and Hansen concluded that it was the affect displayed by the face which caused it to pop out fro m its surrounding distracters. However, Hansen and Hansen's angry face s contained extraneous dark areas which were introduced when they tran sformed Ekman and Friesen's photographs of angry and happy faces into black-on-white sketches. When the original artifact-free gray-scaled v ersions of angry and happy faces were used no evidence for pop out was found. All target faces were found during a serial, self-terminating search regardless of their expression. The angry face in Hansen and Ha nsen's experiments may have popped out from a crowd of happy faces bec ause of a contrast artifact inadvertently introduced when they created their stimuli.