Recognition and familiarity elicited different emotions in Madame M. Her problem was she couldn’t reconcile the two emotions. The delusion of doubles wasn’t a sensory delusion, “but rather the conclusion of emotional judgment.”
.. Our modern understanding of the disorder tells us much about how the brain has separate modules for analyzing the cognitive aspects of recognition, and for feeling the emotional aspects of familiarity.
.. As we’ll see, these functional fault lines in the social brain, when coupled with advances in the online world, have given rise to the contemporary Facebook generation. They have made Capgras syndrome a window on our culture and minds today, where nothing is quite recognizable but everything seems familiar.
.. Some viewed Capgras as a delusion all its own (with its own special psychodynamic causes). Others viewed it as simply one of an array of psychodynamically rooted “delusional misidentification syndromes.” Those included Fregoli delusions, where the sufferer believes that various people are actually the same person in disguise; Cotard’s syndrome, the belief that your blood or organs have been absconded with, or that you don’t exist at all; or reduplicative paramnesia, the sense that a familiar place has been copied and substituted.
.. It was spurred by the shock waves sent by the discovery in the 1950s that using a drug to block a certain type of neurotransmitter receptor was a lot more helpful to a schizophrenic than years of psychotherapy. This fostered the recognition that all behavior is rooted in biology, that aberrancies of behavior and neuropsychiatric disorders are as “real” biologically as, say, diabetes.
.. Discrete damage to the brain can produce someone who can identify the features of a loved one, yet who insists that the living, breathing person in front of them is an imposter. Which turns out to tell us a lot about one of the great false dichotomies about the brain.
.. Selective damage to the vmPFC produces someone who also makes terrible decisions, but of a different type. This person has tremendous difficulty deciding anything; he or she lacks any “gut” intuition in such matters. Moreover, the decisions tend toward cold, heartless pragmatism. When meeting someone, he might say, “Hello, I see that you are quite overweight,” and when chastised about it later, will respond with a puzzled, “But it’s true.”
.. Identification is at the intersection of factual recognition and a sense of familiarity. In this framework, Capgras delusions arise when there is selective damage to the extended face processing network, impairing the sense of familiarity. Factual recognition is intact; you know that this person looks just like your loved one. But they just don’t feel familiar.
.. But this only gets you halfway to the delusion. Suppose there’s one of those quirky moments where your Significant Other says or does something out of character, feels unfamiliar. Wow, that’s not like him, we think. We don’t then conclude, however, that he must have been replaced by an identical imposter. Instead, we find a more plausible explanation—it’s, say, because he didn’t get much sleep.
.. prosopagnosia the mirror of Capgras delusions is the fact that with the former, amid destruction of cognitive recognition, the affective sense of familiarity is still there. Show someone with prosopagnosia a series of faces—Nope, I don’t recognize this person, not that one either—with a picture of a loved in the sequence, and you will see the same disavowal—Nah, don’t recognize this one—but the autonomic nervous system responds to familiarity. Heart rate changes, galvanic skin conductance shifts. Recognition is shot, you insist you’ve never seen this face before in your life, but the affective circuitry of the brain knows exactly who it is—this is the one who makes me feel safe, whose smile and form and scent have greeted me each morning since we joined our lives.
.. we become increasingly vulnerable to imposters. Our social media lives are rife with simulations, and simulations of simulations of reality. We are contacted online by people who claim they know us, who wish to save us from cybersecurity breaches, who invite us to open their links. And who are probably not quite who they say they are.
.. This withering of primate familiarity in the face of technology prompts us to mistake an acquaintance for a friend, just because the two of you have a Snapchat streak for the last umpteen days, or because you both like all the same Facebook pages. It allows us to become intimate with people whose familiarity then proves false. After all, we can now fall in love with people online whose hair we have never smelled.
.. It’s not that loved ones and friends are mistaken for simulations, but that simulations are mistaken for them.