Amygdala and hippocampus fail to habituate to faces in individuals with an inhibited temperament.

"Conflict of Interest None declared."

"We thank Jerome Kagan and Margaret Benningfield for helpful comments on the article and Kristi Simmons for research assistance. Portions of this work were presented at the Cognitive Neuroscience Society meeting, San Francisco, April 2011 and the Society for Biological Psychiatry, San Francisco, May 2011. This work was supported in part by funding from the National Institutes of Health [MH083052 to J.U.B., DA015137 to R.L.C., DA020149 to R.L.C., MH073800 to R.L.C., RR024975 to the Vanderbilt Institute for Clinical and Translational Research]; the American Academy of Child and Adolescent Psychiatry [Summer Medical Student Fellowship to A.H.A.]; and the Vanderbilt University Institute of Imaging Science."