Facial EMG Activity Is Associated with Hedonic Experiences but Not Nutritional Values While Viewing Food Images

Abstract

The physiological correlates of hedonic/emotional experiences to visual food stimuli are of theoretical and practical interest. Previous psychophysiological studies have shown that facial electromyography (EMG) signals were related to subjective hedonic ratings in response to food images. However, because other data showed positive correlations between hedonic ratings and objective nutritional values of food, whether the facial EMG reactions to food images could reflect the hedonic evaluation or nutritional assessment of food remains unknown. To address this issue, we measured subjective hedonic ratings (liking, wanting, valence, and arousal) and physiological signals (facial EMG of the corrugator supercilii, zygomatic major, masseter, and suprahyoid muscles, skin potential responses, and heart rates) while participants observed food images that had objective nutritional information (caloric, carbohydrate, fat, and protein contents). The results revealed that zygomatic major EMG activity was positively correlated with ratings of liking, wanting, and valence, but not with any objective nutritional value. These data indicate that facial EMG signals in response to food images reflect subjective hedonic experiences, but not objective nutritional values, associated with the food item.

Brow and Masticatory Muscle Activity Senses Subjective Hedonic Experiences during Food Consumption

“…Our results also revealed that the ratings of liking, wanting, and valence were not significantly associated with zygomatic major EMG activity with and without adjustment for masticatory EMG and acceleration, which is consistent with previous findings [8]. Although the results of several previous studies testing non-eating tasks revealed that subjective valence ratings were associated with EMG activity measured from both the corrugator supercilii and zygomatic major muscles (e.g., [12]), some studies found that subjective ratings were associated with EMG for only one of these muscles [14,59]. Taken together, our results imply that subjective hedonic experiences during eating are more evidently associated with EMG signals measured from corrugator supercilii EMG compared with zygomatic major EMG.…”

Decoding of facial muscle-brain relation by information-based analysis of electromyogram (EMG) and electroencephalogram (EEG) signals

“…Therefore, the variations in facial muscles and brain activities are linked. The conducted investigation in this study is more advanced comparing to the works [1][2][3][4][5][6][7] which only analyzed the facial muscles' reaction without linking to brain activity.…”

“…Researchers investigating facial muscle activity under varying conditions have reported plenty of prior works in the available literature. For instance, the reported studies that monitored EMG signals in decompression operation [1], analyzed EMG signals to recognize intensive valence and arousal affective [2], evaluated the influence of visual [3], emotional [4], and auditory [5] stimuli on EMG signals; judged smile authenticity by analysis of EMG signals [6], and evaluated the alterations of facial muscle activity in aging [7], are worthy of being mentioned.…”

Emotion Recognition – Recent Advances and Applications in Consumer Behavior and Food Sciences with an Emphasis on Facial Expressions

“…Applications are reported from fine arts but rarely from consumer behavior. For tasting food products or looking at pictures of food products, studies using fEMG have shown that the activity of selected facial muscles correlates with self-reported hedonic responses [55,56].…”