Posted by alexandra_k on December 21, 2004, at 17:02:04
In reply to Re: 1.3, posted by smokeymadison on December 21, 2004, at 16:37:20
There is some evidence that reasoning deficits turn up when the infomation to be processed has a strong affective componant. If you give someone with delusions two arguments (of the same form) and ask if the conclusions follow and one is neutral (about grass and rain) while the other is emotionally loaded (about people trying to kill you) then the faulty logic will show up on the second but not the first task.
This has led to some speculation that delusional subjects reasoning errors are the same as the reasoning errors exhibited by non-delusional subjects who are under a lot of emotional stress.
Here is something you might find interesting:
People with the Cotard delusion may claim that they are dead. It tended to occur in severe cases of depression, and it is less frequent now because of anti-depressants / shock treatment. What has been found is that while normal subjects have a heightened skin galvanisation response (sweat on the skin) to various stimuli - subjects with the Cotard delusion have a global lack of response.If you read the utterance 'I am dead' as expressing a claim about biological death then evidence against the delusion would be such things as 'do you feel your heart beating'. The fact that subjects who said 'I am dead' did not take their heart beating to count as evidence against their delusion was interpreted as evidence for their irrationality.
But lets try another interpretation of the utterance. Imagine (by empathy) how things must seem if you no longer feel affectively connected to either yourself or things in the world. This may plausibly lead to a sense of disembodiment or detachment. We often talk of emotional death or numbness. If this is what subjects with the Capgras delusion are trying to express then it is irrelevant to their expression of this that their heart is still beating! We have simply missed the point.
Can similar stories be told for all the different kinds of delusions?
I shall try...
PS just what a lack (or presence) of skin galvanisation response ammounts to is controversial. I talk about the f'd up galvinisation responses of subjects with the Capgras delusion in 1.4 and hypothesise a finding for subjects with the Fregoli delusion...
poster:alexandra_k
thread:432064
URL: http://www.dr-bob.org/babble/write/20041210/msgs/432548.html