Are attractive people rewarding? Sex differences in the neural substrates of facial attractiveness

Abstract

The current study examined the neural substrates of facial attractiveness judgments. Based on the extant behavioral literature, it was hypothesized that brain regions involved in identifying the potential reward value of a stimulus would be more active when men viewed attractive women than when women viewed attractive men. To test this hypothesis, we conducted an event-related functional magnetic resonance imaging experiment during which participants provided explicit attractiveness judgments for faces of the opposite sex. These individual ratings were subsequently used to perform analyses aimed at identifying the brain regions preferentially responsive to attractive faces for both sex groups. The results revealed that brain regions comprising the putative reward circuitry (e.g., nucleus accumbens [NAcc], orbito-frontal cortex [OFC]) showed a linear increase in activation with increased judgments of attractiveness. However, further analysis also revealed sex differences in the recruitment of OFC, which distinguished attractive and unattractive faces only for male participants.

Figure 1

Top: Response latencies for attractiveness ratings (1= Very attractive; 4 = Not attractive at all) were not significantly different between male and female participants. Bottom: Percentage of responses attributed to each attractiveness rating level was only significantly different between male and female participants for response 4 (Not attractive at all), with females making more of these responses than males.

Figure 2

(A) Coronal sections illustrating regions that increased their activity as a function of increasing judgments of attractiveness. The left OFC (BA11: −9 40 −15) and bilateral NAcc (left: −9 8 −5; right: 9 14 −3) showed this pattern of activity. (B) Coronal sections illustrating regions that increased their activity as a function of decreasing judgments of attractiveness. The right lateral OFC (BA47: 45 26 −11) and right middle frontal gyrus (BA32: 50 42 17), showed this pattern of activity.

Figure 3

Axial sections display left NAcc (top) and right NAcc (middle) and a sagittal section displays mOFC (bottom) spherical regions of interest superimposed on normalized anatomic images. Graphs to the right of each image display signal change (parameter estimates) for attractive and unattractive faces across female and male participants relative to the baseline fixation. Error bars indicate standard error of the mean. Activity in the left and right NAcc was greater for attractive than unattractive faces irrespective or the participants’ gender. Activity in the mOFC exhibited an interaction between facial attractiveness and participant gender displaying greater activity for attractive than unattractive faces only for male participants.