The amygdala is suspected of processing people's strong reactions to personal space violations since these are absent in those in which it is damaged and it is activated when people are physically close.[7] Research links the amygdala with emotional reactions to proximity to other people. First, it is activated by such proximity, and second, in those with complete bilateral damage to their amygdala, such as patient S.M., lack a sense of personal space boundary.[7] As the researchers have noted: "Our findings suggest that the amygdala may mediate the repulsive force that helps to maintain a minimum distance between people. Further, our findings are consistent with those in monkeys with bilateral amygdala lesions, who stay within closer proximity to other monkeys or people, an effect we suggest arises from the absence of strong emotional responses to personal space violation."[7]