Probing “pop-out”: Another look at the face-in-the-crowd effect

Abstract

1988) found that an angry face in a crowd of happy faces can be found faster than a happy face in a crowd of angry faces. They called this finding the face-inthe-crowd effect (FICE). The present experiments replicated this effect for nine-face crowds but not for four -face crowds. Hansen and Hansen concluded that their result was due to "pop out," because they found no reliable effect of crowd size for angry face targets. Contrary to prediction from the "pop out" hypothesis, we found that the position of the target face within the crowd had an effect on reaction time. Such positional effects demonstrate that subjects were scanning the face array to locate the target face . Examination of the literature on the perception of facial expression suggests that the FICE may be produced, at least in part, by the crowds scanned rather than by the target scanned for. The present paper suggests that conclusive evidence of "pop-out" should consist of both the absence oftarget-position effects and the conventionally accepted smallstimulus-set-size effects.C . H. Hansen and R. D. report that the search time to locate a face within an array of other faces depends on the expression of the target face. An angry face in an array of happy faces was found faster than a happy face in an array of angry faces. They call their finding the face-in-the-erowd effect (FICE). In order to argue that "pop-out " is actually occurring, there must be little or no relationship between the number of items in the display and the time taken to find a target embedded in that display (Treisman & Souther, 1985) . This is essentially what C. H. report. They suggest that faces are preattentively searched in parallel for features associated with a threatening expression, so that "an angry face in a happy crowd would pop out and not require an extensive, time-consuming, serial attentive search to discover its presence. . . . [On the other hand,] a happy face in an angry crowd would not be preattentively distinctive [because it is the only face whose expression does not represent a threatening emotion]; it would not pop out and discovering its presence would require a serial search of the faces " (p. 920).There is another requirement that the data must meet if conclusive evidence for "pop out" is to be found . If "pop out " occurs, reaction time to locate the angry face should not be influenced by the position of the target face Experiment 1 was conducted by Carol Hampton, as an honors independent study project, and Experiment 2 was conducted by Louis Bersine, as an independent study project. These projects were supervised by Dean G. Purcell . We wish to thank Eric Hiris for helping with data collection and analysis, and Alan L. Stewart for a critical review of the manuscript.

Tagging multiple emotional stimuli: Negative valence has little benefit.

“…For example, Eastwood and colleagues (2001) demonstrated in a visual search experiment that a negative target face presented amongst neutral faces could be detected more efficiently (i.e. more rapidly, and with a shallower search slope) than a positive face (see also Fox et al, 2000;Hansen & Hansen, 1988;Hampton et al, 1989). Furthermore, some authors have argued that negative expressions can be detected preattentively, again suggesting that emotional valence might act in the same way as a salient low-level feature in some situations (Öhman, Lundqvist & Esteves, 2001).…”

Differential attentional guidance by unattended faces expressing positive and negative emotion

“…Although these findings suggest that focal attention is more readily guided by an angry face than by a happy face, there is an equally plausible alternative interpretation. Perhaps the reason it took longer to detect the target face expressing happiness than to detect the target face expressing anger is that it takes longer to search through angry distractor faces than it takes to search through happy distractor faces (Hampton, Purcell, Bersine, Hansen, & Hansen, 1989).…”

“…In a number of studies, the underlying assumption has been that the only satisfactory evidence that a face guides focal attention is a pattern of findings showing that the speed with which a face is detected is relatively unaffected by the number of distractor faces (e.g., Hampton et al, 1989;Nothdurft, 1993;Purcell et al, 1996;White, 1995). In other words, the slope of the search function across increasing numbers of distractors should be relatively flat.…”

“…1 In the present experiments, we compared the slopes of the search functions for locating schematic faces expressing positive and negative emotions in order to assess the relative effectiveness of positive and negative emotional expressions in guiding the focus of attention (see Figure 1 for examples of the stimulus displays). Both the positive and the negative faces were embedded in displays of faces with a neutral emotional expression, to ensure that any differences in the slopes of the search functions were not due to differences in the distractor context (see Hampton et al, 1989). In order to have a sensitive measure of the presence of attentional guidance by faces expressing emotions, the number of distractor faces with a neutral expression was varied widely, with the resulting set sizes ranging from 7 to 19 faces.…”

Visual search is not blind to emotion

“…However, because these studies did not use consistent distractor contexts, it is possible that the results are attributable to distractor properties (e.g., see Hampton, Purcell, Bersine, Hansen, & Hansen, 1989). Williams, Moss, Bradshaw, and Mattingley (2005) also cite evidence for different search efficiencies for target faces; these efficiencies depend on emotional expressions.…”