Face perception is modulated by sexual preference Kranz, F. & Ishai, A. Institute of Neuroradiology University of Zurich Zurich, Switzerland Institute for Biomedical Engineering Swiss Federal Institute of Technology Zurich, Switzerland

INTRODUCTION  Face perception modulated by distributed cortical network  Visual cortex, limbic system, PFC  Cognitive factors  Attention and emotion  Visual imagery  Memory

HYPOTHESIS A greater response (fMRI) to sexually preferred faces is modulated by the reward circuitry. (e.g. thalamus, medial orbitofrontal cortex)

PROCEDURE  10 HeW, 10 HeM, 10 HoW, 10 HoM (age: M = 26±3 yrs)  Measured reaction times in assessing attractiveness of face stimuli  fMRI scan – neural activation

PROCEDURE  Viewed photos of faces/phase- scrambled faces  8 trials – 3 viewing, 5 assessing  Viewing: 60M, 60F  10 faces, 7 P-S faces..  Assessing facial attractiveness: 100M, 100F  10 faces, 4 P-S faces…

RESULTS - RT  M/F faces assessed similarly for attractiveness across all groups  Regardless of gender or sexual orientation

RESULTS - fMRI  Similar patterns of activation in face- selective regions across all groups AMYGDALA FUSIFORM GYRUS

RESULTS - fMRI  In mdT and OFC: Attractive faces  stronger activation than unattractive or neutral faces  M faces  greater response in HeW, HoM  F faces  greater response in HeM, HoW

DISCUSSION  Face perception activates regions:  Processing facial identity and expression  Visual cortex, limbic system, PFC  Processing assessment of facial beauty  PFC, reward circuitry

DISCUSSION  Similar responses from M/F U,N,A, faces  M/F equally notice + respond to beauty of same and opposite sex  Both in RTs AND neural activation in face-selective regions  Gender processed in cortical network mediating face perception

DISCUSSION  Stronger activation in reward circuitry (mdT, OFC)  In response to sexually preferred faces  reward value of stimuli  HeW, HoM respond to M faces  HoW, HeM respond to F faces

CONCLUSION  Face stimuli  similar activation  Visual cortex (lateral fusiform gyrus)  Limbic system (amygdala)  Prefrontal regions  Sexually relevant faces  Stronger neural responses in reward circuitry  Represents the value of the stimuli

 Strengths  Inherently interesting!  Complete results section   Explicitly assessed facial attractiveness  Limitations  Procedure was poorly written and difficult to interpret

NEXT STEP?  Do the results found also apply to transgendered or transsexual individuals?  No differential effect in amygdala – emotion?  Role of OFC in sex-related motivational behaviours