the amygdala plays key roles in emotion and social cognition , but how this translates to face - to - face interactions involving real people remains unknown . 
 here we found that a patient with complete amygdala lesions lacks any sense of personal space . 
 furthermore , healthy individuals showed amygdala activation to close personal proximity . 
 the amygdala may be required to trigger the strong emotional reactions normally following personal space violations , thus regulating interpersonal distance in humans .