Winston et al. (2007) used fMRI to explore how the brain responds to both attractive and unattractive faces.

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• Winston et al. (2007) used fMRI to explore how the brain responds to both attractive and unattractive faces. They found that unattractive faces elicited increased activation in the insula, a region of the brain associated with negative emotional responses, such as disgust or discomfort. This suggests that viewing unattractive faces may activate emotional responses linked to aversion or disinterest.
• Reference: Winston, J. S., O'Doherty, J., Kilner, J. M., Perrett, D. I., & Dolan, R. J. (2007). Brain systems for assessing facial attractiveness. Neuropsychologia, 45(1), 195-206. (https://sci-hub.ru/https://pubmed.ncbi.nlm.nih.gov/16828125/)