Because of the large numbers of reciprocal connections between brain areas, the results of processing in one part of the brain can easily affect processing in other parts. Figure 5.2 displays many interactions among the dopamine system, which includes the nucleus accumbens, the cognitive appraisal system in the prefrontal cortex, and the emotional perception system involving the amygdala and the insula. There is no central processor that coordinates all the results and yields a decision. Rather, the brain's reaction to a scary face or other sensory stimulus comes about through the dynamic interaction of external sensory perception, internal sensory perception, cognitive appraisal, and positive and negative valuation. Note that the connections between brain areas in the EMOCON model are reciprocal, based on neural evidence that there is extensive feedback between neural populations in each pair of regions.