Brain responses to facial attractiveness induced by facial proportions: evidence from an fMRI study.

Hui Shen,Desmond K P Chau,Ling-Li Zeng,Dewen Hu,Weixiong Jiang,Jianpo Su,Jufang He,Jintu Fan

doi:10.1038/srep35905

Abstract

Brain responses to facial attractiveness induced by facial proportions are investigated by using functional magnetic resonance imaging (fMRI), in 41 young adults (22 males and 19 females). The subjects underwent fMRI while they were presented with computer-generated, yet realistic face images, which had varying facial proportions, but the same neutral facial expression, baldhead and skin tone, as stimuli. Statistical parametric mapping with parametric modulation was used to explore the brain regions with the response modulated by facial attractiveness ratings (ARs). The results showed significant linear effects of the ARs in the caudate nucleus and the orbitofrontal cortex for all of the subjects, and a non-linear response profile in the right amygdala for only the male subjects. Furthermore, canonical correlation analysis was used to learn the most relevant facial ratios that were best correlated with facial attractiveness. A regression model on the fMRI-derived facial ratio components demonstrated a strong linear relationship between the visually assessed mean ARs and the predictive ARs. Overall, this study provided, for the first time, direct neurophysiologic evidence of the effects of facial ratios on facial attractiveness and suggested that there are notable gender differences in perceiving facial attractiveness as induced by facial proportions.

Highlights

Facial attractiveness is a facial attribute that conveys significant biological advantages as expressed in mating success[1], earning potential[2] and longevity[3], across different cultures and age groups[4]
We used a linear term of the mean facial attractiveness ratings with a one-sample t-test to evaluate the linear changes in the blood oxygen level dependent (BOLD) signal relative to the facial attractiveness
A second-order term in the polynomial expansion of facial ARs was used to test whether the addition of a quadratic term accounts for the change in the BOLD signal relative to the subject-specific attractiveness ratings

Summary

Introduction

Facial attractiveness is a facial attribute that conveys significant biological advantages as expressed in mating success[1], earning potential[2] and longevity[3], across different cultures and age groups[4]. A large body of studies have found that facial attributes that contribute to attractiveness include averageness[6,7,8,9], symmetry[9,10], sexual dimorphism[11,12], expression[13], and skin texture[14]. We used computer-generated, yet realistic face images that had varying facial proportions as stimuli to investigate the brain responses to facial attractiveness as induced by facial proportions This approach allowed us to explore only the effect of facial ratios on facial attractiveness using an event-related fMRI design, by manipulating the individual facial ratios and controlling the effects of other confounding factors, such as the hairstyle, skin texture and expression, to test whether some of the facial ratios or their combinations contribute to facial attractiveness

Methods

Results

Discussion

Conclusion