A functional magnetic resonance imaging (fMRI) study showed that the amygdala’s reaction to negative emotional stimuli is greater in magnitude/intensity and volume in people who miss a night of sleep when compared to a control group. This study also showed that the connections between the amygdala and the MPFC were weaker in the sleep deprived group. This means that the amygdala’s reactions can’t be inhibited as well by the MPFC in people who lack sleep.