Evolutionary Evidence – Visual Search Paradigm

The visual search paradigm is one method to investigate how fear focuses our attention on a threat and prepares us for action to avoid the threat. In the visual search paradigm, participants are instructed to find specific target objects located among many control or distractor targets. For instance, in the two top photos in Figure 6, participants would be looking for the anger (left) or joy (right) face among all the neutral faces (called the “face in the crowd effect”). Generally, studies have found that people are faster to identify and more accurately identify the one anger face in the crowd than the one joyful face (Pinkham et al., 2010). Further, participants are faster and more accurate in identifying anger expressions than joy expressions in crowds of emotional crowds – as shown in the bottom two photos. Similar findings were obtained when participants were faster to locate a snake/spider among neutral objects and slower to locate a neutral object among snakes/spiders (Öhman, Flykt, et al., 2001). Together, these findings are taken as evidence of evolutionary preparedness to act in response to potential threats to our survival.

Basic emotions researchers believe that as part of the fear emotional experience, the brain, particularly the amygdala, is biased to quickly identify threatening facial expressions in other people, such as an anger facial expression. This threat-advantage bias means that over time, our brains and visual systems evolved to quickly and accurately identify threat in facial expressions and in animals our environment (Horstmann & Bauland, 2006; Öhman, Lundqvist, et al., 2001; Öhman & Mineka, 2001). Yet, Pinkham et al. (2010) findings suggest this mechanism operates best when the threatening facial expression occurs in a neutral versus emotional crowd, suggesting that mismatched emotional expressions could distract our amygdala from quickly and accurately detecting the threat.