Threat modulates perception of looming visual stimuli

Abstract

Among the most critical of visual functions is the detection of potentially hazardous or threatening aspects of the environment. For example, objects on a collision course with an observer must be quickly identified to allow sufficient time to prepare appropriate defensive or avoidant responses. Directly approaching objects produce a specific accelerating pattern of optical expansion, known as 'looming, which in theory exactly specifies time-to-collision independent of object size or distance. Such looming stimuli have been shown to trigger stereotyped defensive responses in both monkeys [1] and human infants [2]. Psychophysical results in adult participants have similarly suggested sensitivity to looming at early stages of visual processing [3]. Such findings indicate specialization of the visual system to detect and react to such 'looming' stimuli, and have contributed to the traditional view of looming as a purely optical cue to imminent collision [1]. Here, we investigated whether the semantic content of a looming visual stimulus affects perceived time-to-collision by manipulating its threat value. We show that time-to-collision is underestimated for threatening (snakes and spiders) compared to non-threatening (butterflies and rabbits) stimuli. Further, the magnitude of this effect is correlated with self-reported fear. Our results demonstrate affective modulation of the perception of looming stimuli, and suggest that emotion shapes basic aspects of visual perception.

Cynophobic Fear Adaptively Extends Peri-Personal Space

“…This result seems consistent with previous results demonstrating that individuals underestimate the time at which a visual looming stimulus will collide with them when the stimulus is threatening (snakes, spiders, angry faces) compared to when it is non-threatening (butterflies, rabbits, neutral faces) (18, 19). Vagnoni et al also show that this underestimation of time-to-collision is bigger for individuals who are fearful of the threatening stimulus; the size of the underestimation is linked to individuals’ level of snakes- and spider-related anxiety.…”

Emotional modulation of interval timing and time perception

“…Looming objects on a collision course with an individual have been associated with faster time-to-contact responses than objects that would miss the individual (101). Furthermore, looming threats appear to move faster in approach than non-threatening objects, suggesting the importance of evaluating the threat to one’s person in driving the distortions (e.g., 19, 20, 244). The underestimation of time-to-contact estimates has been shown to positively correlate with fear ratings (244).…”

Subliminal Impending Collision Increases Perceived Object Size and Enhances Pupillary Light Reflex

“…Threat-related signals have been found to bias human visual perception and trigger physiological responses. For example, people are inclined to overestimate the perceived proximity (Cole et al, 2013), size (Vasey et al, 2012), and duration (Tipples, 2011) of threatening objects, or to underestimate the time to contact with them (Vagnoni et al, 2012). Observers with fear of heights overestimate the perceived vertical distances and the sizes of objects when looking down from a high place (Teachman et al, 2008; Stefanucci and Proffitt, 2009).…”