Friday, June 15, 2012

Transient global amnesia and free will


Transient global amnesia is a condition in which a person temporarily loses the ability to create new memories.  One of the hallmarks of the disorder is that the patient's short term memory periodically resets, frequently resulting in the patient getting stuck in a loop.  Unlike Phil, Bill Murray's character in Groundhog Day, the patient doesn't remember events from cycle to cycle.  However, observers get a taste for Phil's surreal experience as they watch the patient repeat the same questions, statements, and behaviors over and over again like a broken record.

An episode of Radiolab (at 7:15) features a woman suffering from transient global amnesia, whose memory resets every 90 seconds.  Her daughter recorded the exchange with her mother, which replayed almost verbatim every 90 seconds over the course of several hours:
Mother:  "What's the date?"
Daughter:  August 24
Mother:  My birthday has already passed?
Daughter:  Yes
Mother:  "Darn" (same inflection) (laughs)
Mother:  "What happened?"
Daughter:  "You were working in the garden ... I called the paramedics"
Mother:  (eyes widening)  "This is so creepy"

[Reset]
Dr. Jonathan Vallejos, who treated the woman, has seen a number of these cases. According to Dr. Vallejos:
Everyone becomes a broken record, down to the phrasing of the sentences.  It makes the brain seem a little more like a machine.  You give the machine exactly the same set of inputs and see if the output ever varies.  It doesn't.  It almost seems like the patient has no free will.
I would agree with Dr. Vallejos if he removed "little more" and "almost."  The brain is a machine.  The patient does not have free will.  If there is any better evidence that the brain is computer and performs determined actions in response to external input, I have not seen it.

2 comments:

  1. Whew, what a relief, because for us "compatiblists" (see: http://canonizer.com/topic.asp/128/2 ), the only way to be 'free' is if we can reliably, absolutely, deterministically make the best choice. Anything, such as randomness or some twisted kind of free will that possibly enables us to make a choice that deviates from what we really want, destroys that true free will. Certainly, God, once there is one, will absolutely and deterministically always make the right choice, for as long as he fails to do so, for whatever reason, he will not yet be the perfect God, right?

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  2. As compatiblists define free will, that is true. Determinism does not rule out free will.

    My question is this: when a computer is executing a program, is it free? A person with transient global amnesia appears to operate just like a computer. It would be interesting to test. If you kept the inputs the same from iteration to iteration, would people behave exactly the same way without variation? In the case of this story, there was some minor variation, because the daughter was not trying to test a hypothesis about free will. It is like Groundhog Day. The initial conditions always start out the same. The only variables are the external inputs.

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