Have you ever seen someone else’s doppelganger? That is, have you ever seen someone who looks exactly like a friend or family member, but is in fact just a random person? I am sure most of us have. Now, imagine that doppelganger you see is actually your mother, and it’s your brain that’s deceiving you. It could happen. In a strange and very rare syndrome called the Capgras Delusion, patients believe that someone close to them has been replaced by an impostor.
When your brain perceives something, it actually undergoes a rather long and complicated process of perception. The image is first seen on the retina, where it travels to the occipital and temporal lobes. Within the temporal lobe of the brain, the fusiform gyrus is responsible for facial recognition (it’s known as the “face area” of the brain). Connections between the fusiform gyrus and amygdala, a structure usually associated with emotion, exchange the information and determine whether it is of emotional significance to the individual.
The Capgras Delusion is caused by damage to these connections. As the brain is no longer able to exchange information between the fusiform gyrus and the amygdala, the individual cannot assign an emotional importance to the sight of the person in front of them. In this case, the brain assumes that the person must be attempting to imitate their mother, as she looks eerily similar. There’s just too many similarities between this person and someone you know, and your brain reacts in a rather unpleasant way.
It’s a rather unfortunate syndrome, as it prevents the patient from assigning emotional significance to most things that they are able to see. However, the disorder is entirely visual: if a patient suffering from Capgras hears their mother or father (or other person close to them), they are able to easily conclude that it is actually their parent.
Imagine coming home to your parents. Except you don’t recognize them as your parents, only that they’re eerily similar to everything you know about your parents. They know your embarassing childhood stories, your scars, all your friends. Yet to you, they’re completely a stranger, a perfect replica who is undecidedly not your parent. It’s a pretty creepy thought.
-Roberto Barroso Luque
Ogden, J. (n.d.). Retrieved from http://www.psychologytoday.com/blog/trouble-in-mind/201208/the-capgras-delusion-you-are-not-my-wife
Ramachandran, V. (0). Retrieved from http://www.ted.com/talks/vilayanur_ramachandran_on_your_mind.html