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Explore how neuroimaging reveals our responses to faces, from attraction to avoidance, and how social cues influence brain activity. Discover the impact of facial expressions and dynamic movements on brain responses.
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Lecture 11 May 2005 (Updated Dec 2006) Neuroimaging and attitudes to faces
Neuroimaging + attitudes to faces • Attraction (ventral thalamus, medial orbito-frontal cortex) • attractiveness and social interest interact to determine the ‘reward value’ of faces • Avoidance (insula) - disgust expressions - unattractive faces - untrustworthy faces • Dynamic emotion - moving faces
-3 -3 Medial orbito-frontal cortex Attractive Faces O’Doherty et al. 2003 Medial orbital-frontal cortex is a reward centre Activity increased by attractive faces
Smiling and Neutral Faces Happy Neutral
0.10 Effect size 0.05 0.00 Mid-range Neutral Happy Attractiveness and Smiling Effect of attractiveness on medial orbito-frontal cortex greatest when faces are engaging the viewer
1. Attractiveness + social interest Attractive faces activate ‘reward’ structures more than unattractive faces Responses to attractive faces biggest when the person is engaging with us (i.e. smiling) In O’Doherty et al. engagement was signalled by expression Engagement can also be signalled by direct gaze
Direct GAZE Averted Kampe et al. 2001
Kampe et al. 2001 ventral thalamus activity modulated by attractiveness & gaze direction
1. Attractiveness + social interest Attractive faces activate ‘reward’ structures more than unattractive faces (ventral thalamus, medial orbito-frontal cortex) Responses to attractive faces biggest when the person is engaging with us (i.e. smiling, direct gaze) O’Doherty et al. 2003 Kampe et al. 2001
2. Avoidance - disgust expressions - unattractive faces - untrustworthy faces
Disgust Expressions & Insula Cortex (Phillips et al. 1997) Increased insula activity when viewing disgusted faces
2. Avoidance Insula cortex also activated by disgusting odours Keyser et al. (2004)
+22 R Insula Lateral PFC Unattractive Faces Activity increases with unattractive faces O’Doherty et al.
+22 R Insula Lateral PFC Untrustworthy Faces Increased insula response to faces judged untrustworthy (Winston et al., 2002 Nature Neurosci)
2. Avoidance Faces we might want to to avoid: unattractive (possibly unhealthy?) disgusted (there is a source of contagion about?) untrustworthy (they’ll cheat us?) activate the insula cortex [also disgusting odours]
Attraction and avoidance (Key themes) Attraction Ventral thalamus Medial orbito-frontal cortex !Approach this person! Avoidance Insula cortex ‘disgust region’ !Avoid this person! Activated by attractive faces (especially if engaging with you) Activated by unattractive, untrustworthy and disgusted faces
Dynamic expressions All the studies we’ve discussed in this course used static images Sato et al. asked if facial movements might communicate important information Dynamic facial expressions caused more brain activity than static expressions Dynamic (non-face) mosaics caused no more brain activity than static mosaics Movement matters!
Future directions Individual differences in neural responses to faces Use of dynamic faces Use of computer graphic methods to manipulate dynamic facial cues Integration of social and physical cues in perception
Next week 4 key revision topics covered Does attractiveness signal health? Self-resemblance as a cue of kinship Effects of hormonal profile on face preferences Condition-dependent mate preferences