I chose the perceptual disorder known as Capgras Delusion. This is a perceptual disorder where one holds an irrational belief that a loved one has been replaced by an identical imposter. This disorder was named afterJoseph Capgras, a French psychiatrist who described the first case of Madame M who believed her husband had been exchanged for a double. This disorder is reported in late stage Alzheimer’s dementia but also typically developed after lesions in the right hemisphere of the brain.