Psyb57 chapter 2: the neural basis for cognition. Rare; seems to be one of the accompaniments to alzheimer"s disease and is sometimes observed in the elderly. The people with this are convinced that the people they know are not who they appear to be. They think that their family members have been replaced by imposters. This can lead to paranoid suspicions about why a loved one has been replaced and why no one is willing to acknowledge this replacement. Facial recognition involves two separate systems: cognitive appraisal, emotional appraisal. The emotional appraisal is disrupted in this syndrome leading to the intellectual identification without the familiarity response. Right temporal lobe is damaged in capgras patients and this damage disrupts circuits involving the amygdala. Amygdala serves as an emotional evaluator helping an organism to detect stimuli associated with threat or danger and for detecting positive stimuli.