FIGURE 3.

Overview of the modified fear-conditioning/fear-extinction protocol. (A) At baseline, participants were conditioned to fear two of three stimuli (i.e., blue truck and red car) by a mild but not painful electric shock (Pace-Schott et al., 2009), and skin conductance was measured. (B) On the same day, participants underwent extinction of the blue truck, but not the red car. Extinction was demonstrated by a reduction in skin conductance. (C) After 6 weeks of morning light treatment (blue or amber), participants returned to the lab and were shown the same stimuli again and skin conductance was measured. (D) Participants were shown the same stimuli, in a different visual context, while undergoing functional magnetic resonance imaging (fMRI).