Viewing images of snakes accelerates making judgements of their colour in humans: red snake effect as an instance of ‘emotional Stroop facilitation’

Abstract

One of the most prevalent current psychobiological notions about human behaviour and emotion suggests that prioritization of threatening stimuli processing induces deleterious effects on task performance. In order to confirm its relevancy, 108 adults and 25 children were required to name the colour of images of snakes and flowers, using the pictorial emotional Stroop paradigm. When reaction time to answer the colour of each stimulus was measured, its value was found to decrease when snake images were presented when compared with when flower images were presented. Thus, contrary to the expectation from previous emotional Stroop paradigm research, emotions evoked by viewing images of snakes as a biologically relevant threatening stimulus were found to be likely to exert a facilitating rather than interfering effect on making judgements of their colour.

Delayed disengagement of attention from snakes in children with autism

“…Similar experiments reported in the past have consistently shown that detection of a tilted straight line target among vertical straight line distractors is easier than vice versa, and that detection of a snake among flower distractors is easier than vice versa. This contrasting pattern for the two related tasks is known as a “search asymmetry” effect (Treisman and Souther, 1985; Treisman and Gormican, 1988) and was again confirmed by the present study in children both with and without autism.…”

Negative emotion evoked by viewing snakes has a motivating effect on cognitive processing in human children with or without intellectual disability

“…A 22‐inch monitor connected to a personal computer was placed on a table. An adapted single‐trial version of the pictorial emotional Stroop task (Constantine et al., ; Shibasaki et al., ; 9 was used in the present experiment. Participants were told by an experimenter, who had not been notified about the purpose of this study, that they would see a series of color‐filtered images, and they were instructed to indicate the color of each image as quickly as possible via a key‐press, while ignoring the content of each image.…”

“…The relationship between keypad position and color was counterbalanced across the participants. More detailed information about the protocol has been provided elsewhere (Shibasaki et al., ).…”

“…Asserting the opposite notion, Charles Darwin () claimed that “a man or animal driven through terror of desperation, is endowed with wonderful strength” and argued that these responses are adaptive because men and animals possessing them are more adept at avoidance when exposed to evolutionarily dangerous stimuli. Recently, Darwin's argument was experimentally confirmed by a study (Shibasaki, Isomura, & Masataka, ) in which 108 adults and 25 children were required to name the color of images of snakes and flowers (Constantine, McNally, & Hornig, ). The reaction time (RT) to name the color of each stimulus was found to be shorter when snake images were presented as compared to when flower images were presented in both adults and children.…”

“…If fear evoked by viewing snakes facilitates perception of the animals in individuals with DS, as it is known to do in neurotypical individuals (Shibasaki et al., ), then naming the color of snakes’ images should also be facilitated in individuals with DS as well. Such facilitation would not be observed if the unresponsiveness of individuals with DS to social danger signals extends to nonsocial danger signals, as represented by snakes.…”