Background: Prepulse inhibition (PPI) of the startle reflex reflects early stages of information
processing and is modulated by selective attention. Animal models indicate medial frontal-
thalamic circuitry is important in PPI modulation. We report data from the first functional
magnetic resonance imaging (fMRI) study examining whether attending to or ignoring a
prepulse differentially activates brain areas within this circuitry. Methods: Ten healthy
subjects received structural and functional MRI. During fMRI acquisition, subjects heard …