The purpose of the study is to determine preattentive mechanisms extracting information which is useful for the perception of facial expression. Face images were created from areas with different amplitude of contrast modulation. It was found that the higher the contrast of the regions from which the face is formed, the more accurately the emotion is determined. It is concluded that the areas with the greatest contrast are more informative for the perception of facial expression, and second-order visual filters are able to preattentively extract these areas from the image.