Thursday, February 6, 2014

Capgras delusion (or Capgras syndrome)

From wikipedia:

The Capgras delusion (or Capgras syndrome) (pron: kăhp′grah IPA:/kap·'grɑ:/)[1] is a disorder in which a person holds a delusionthat a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor. The Capgras delusion is classified as a delusional misidentification syndrome, a class of delusional beliefs that involves the misidentification of people, places, or objects (usually not in conjunction).[2] It can occur in acute, transient, or chronic forms. Cases in which patients hold the belief that time has been "warped" or "substituted" have also been reported.[3]
The delusion most commonly occurs in patients diagnosed with paranoid schizophrenia, but has also been seen in patients suffering from brain injury[4] and dementia.[5] It presents often in individuals with a neurodegenerative disease, particularly at an older age.[6] It has also been reported as occurring in association with diabeteshypothyroidism andmigraine attacks.[7] In one isolated case, the Capgras delusion was temporarily induced in a healthy subject by the drug ketamine.[8] It occurs more frequently in females, with a female:male ratio of 3:2.[9]
The information gathered from studying people with the Capgras delusion has theoretical implications for understanding face perception and neuroanatomy in both healthy and unhealthy individuals.[2]
Link -

Notes from the video:

- a person see - stimulus  reaches the temporal lobe - then there is identification - then it reaches - the amygdala - gateway to the limbic system - that contains the emotional system of  the brain - response to what we look at ( When you see your mom you have love and veneration - an emotion created)

- but for those with rupture of vein connecting to the amygdala (had a car accident and suffered severe head trauma/concussion) - the information processed - but no appropriate response or it is missing - no emotional connection (seeing mother that recognize to looks like mom - but believed to be an impostor)

- but when a person suffering from capgras delusion is called over the phone  - the person could identify/recognized the voice and would have proper emotional connection/response to the person talked to (but not seeing just hearing). The auditory nerve has different pathway to the amygdala so a sufferer of capgras delusion will have an appropriate response to an auditory stimulus, voice of loved ones could be identified with an appropriate emotion.

"Closely link is the intellectual view of the world to your basic emotional reaction to the world" - Dr. V.S. Ramachandran, Director of the Center for Brain and Cognition at UCSD