Facial disgust in response to touches, smells, and tastes.

Abstract

Disgust serves to defend the body from the entry of toxins and disease. Central to this function is a strong relationship with the proximate senses of smell, taste, and touch. Theory suggests that distinct and reflexive facial movements should be evoked by gustatory and olfactory disgusts, serving to impede bodily entry. While this hypothesis has received some support from facial recognition studies, whether smell and taste disgusts actually produce distinct facial responses, is unknown. Moreover, there has been no assessment of the facial response evoked by contact with disgusting objects. To address these issues, this study compared facial responses to touch, smell, and taste disgusts. Sixty-four participants were asked to touch, smell, and taste disgust-evoking and neutral control stimuli, and rate them on disgust, on two occasions-first, while they were video recorded and second, with facial electromyography (EMG) applied (measuring levator labii and corrugator supercilii activity). Videos were coded for facial expressions by humans and for facial action units (FAUs) by machines. Self-report data confirmed the disgust stimuli as highly disgusting. Comparison of the overall pattern of FAUs evoked by touch, smell, and taste disgusts, indicated two distinct facial disgusts for the proximate senses-a chemosensory and a tactile-disgust face. The nose wrinkle and upper lip raise were central to all facial disgusts, indicating their centrality to the disgust face. Several facial disgusts appear to exist, each with different functional goals.

The Functions of Human Touch: An Integrative Review

“…The relationship between coldness and disgust likely occurred because wetter objects feel colder (Filingeri et al, 2014). Objects perceived as disgusting are also touched for shorter durations than those perceived as neutral or pleasant (Saluja et al, 2023). Thus, the tactile sense can detect textures associated with pathogens and their recognition instigates disease avoidant reactions.…”

Differential involvement of the senses in disgust memories

“…involving smell, taste and touch-are suggested to result in more intense disgust experiences than distal sensory disgust cues-i.e. involving vision and audition [7][8][9][10][11]. It has been reasoned that proximal sensory cues are more intense elicitors of disgust because pathogens and toxins enter the body at surfaces the proximal senses bind to-i.e.…”

“…nasal passageways (smells), mouth (tastes and smells) and skin openings (touch). In contrast, sights and sounds often signal distant potential harms, thereby posing a less immediate threat than proximal sensory disgusts [7,[9][10][11]. If proximal sensory cues evoke more intense disgust than distal sensory cues, memories of disgusting experiences should feature smelling, tasting and touching to a greater degree than seeing or hearing.…”