Stability of amygdala BOLD response to fearful faces over multiple scan sessions.
We used fMRI to examine amygdala activation in response to fearful facial expressions, measured over multiple scanning sessions. 15 human subjects underwent three scanning sessions, at 0, 2 and 8 weeks. During each session, functional brain images centered about the amygdala were acquired continuously while participants were shown alternating blocks of fearful, neutral and happy facial expressions. Intraclass correlation coefficients calculated across the sessions indicated stability of response in left amygdala to fearful faces (as a change from baseline), but considerably less left amygdala stability in responses to neutral expressions and for fear versus neutral contrasts. The results demonstrate that the measurement of fMRI BOLD responses in amygdala to fearful facial expressions might be usefully employed as an index of amygdala reactivity over extended periods. While signal change to fearful facial expressions appears robust, the experimental design employed here has yielded variable responsivity within baseline or comparison conditions. Future studies might manipulate the experimental design to either amplify or attenuate this variability, according to the goals of the research.
Johnstone
Tom
T
W.M. Keck Laboratory for Functional Brain Imaging and Behavior, University of Wisconsin, WI 53705, USA. itjohnstone@wisc.edu
Somerville
Leah H
LH
Alexander
Andrew L
AL
Oakes
Terrence R
TR
Davidson
Richard J
RJ
Kalin
Ned H
NH
Whalen
Paul J
PJ
D000328:Adult; D000679:Amygdala / Q000378:metabolism* / Q000502:physiology*; D001007:Anxiety / Q000523:psychology; D005149:Facial Expression; D005239:Fear / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D010100:Oxygen / Q000097:blood*; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results
D010100:Oxygen