Neural responses to masked fear faces: sex differences and trauma exposure in posttraumatic stress disorder.
Although women have a greater propensity than men to develop posttraumatic stress disorder (PTSD) following trauma, sex differences in neural activations to threat have received little investigation. This study tested the prediction that trauma would heighten activity in automatic fear-processing networks to a greater extent in women than in men. Functional magnetic resonance imaging (fMRI) data were recorded in 23 participants with PTSD (13 women, 10 men), 21 trauma-exposed controls (9 women, 12 men), and 42 non-trauma-exposed controls (22 women, 20 men) while they viewed masked facial expressions of fear. Exposure to trauma was associated with enhanced brainstem activity to fear in women, regardless of the presence of PTSD, but in men, it was associated only with the development of PTSD. Men with PTSD displayed greater hippocampal activity to fear than did women. Both men and women with PTSD showed enhanced amygdala activity to fear relative to controls. The authors conclude that greater brainstem activation to threat stimuli may contribute to the greater prevalence of PTSD in women, and greater hippocampal activation in men may subserve an enhanced capacity for contextualizing fear-related stimuli.
School of Psychology, University of New South Wales, Sydney, Australia. kfelmingham@psy.unsw.edu.au
Kim
K
Felmingham
Leanne M
LM
Williams
Andrew H
AH
Kemp
Belinda
B
Liddell
Erin
E
Falconer
Anthony
A
Peduto
Richard
R
Bryant
D000679:Amygdala / Q000378:metabolism*; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001933:Brain Stem / Q000378:metabolism*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005145:Face; D005149:Facial Expression; D005239:Fear; D005260:Female; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D008016:Life Change Events; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010470:Perceptual Masking; D012737:Sex Factors; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology*
D010100:Oxygen