Activation of the medial prefrontal cortex and extended amygdala by individual ratings of emotional arousal: A fMRI study

Background: Significant differences between individual responses to emotional stimuli can be important for the study of emotion. We investigated whether incorporating individual ratings of emotional arousal in the analysis of functional magnetic resonance imaging (fMRI) data improves the detection of activation in the medial prefrontal cortex (MPFC) and sublenticular extended amygdala (SLEA), areas implicated in the processing of emotional salience. Methods: Healthy subjects viewed counterbalanced blocks of aversive, nonaversive, and blank images. Outside the scanner, they rated the intensity of emotional arousal (salience) of each presented picture. Results: Incorporating the subject's response to each stimulus by using individualized regressors produced more robust activations within MPFC and SLEA compared with a simple boxcar regressor, identical for all subjects. Conclusions: Our findings demonstrate that individual behavioral data are useful in improving detection of activation in block-design functional imaging studies.