Advanced Parkinson's disease: a form of 'nirvana'?
I had another interesting idea when reading about Karl Friston’s free energy hypothesis of the brain (see previous post).
Friston says that all action results from the brain trying to minimise prediction error. A simple example:
I expect a box to be empty. When I open the box * gasp * - there’s a cat inside (alive, definitely alive). I can now do one of two things:
Adjust my expectations: change my brain’s model of the box to include the fact that it contains a cat.
Act: take the cat out of the box and * phew *, order is restored. (In fact of course there are many many possible actions I could take in response to this surprise, but let’s keep it simple).
Friston contends that all of our actions stem from a version of picking option 2 in response to a prediction error. (I haven’t quite worked out how planned actions that we fully expect to have to perform fit into this framework - if anyone can help me out with that I’d be grateful!)
Parkinson’s disease is characterised by hypoactivity, and also a lack of dopamine. Dopamine is thought to be heavily involved in the signalling of prediction errors. Friston’s theory explains the hypoactivity seen in Parkinson’s thus:
The brain lacks dopamine, therefore dopaminergic prediction error signalling pathways are under-active.
This is interpreted as ‘no prediction error’.
Therefore, the brain decides ‘all is well, no action required’.
I’d always imagined having advanced Parkinson’s disease to feel a little like ‘locked-in syndrome’ - trapped in an unmoving body. Friston’s model, though, suggests that sufferers feel no urge to act. They simply exist.
Is advanced Parkinson’s similar to nirvana? Pure being with no urge to act?
(I’m not suggesting that Parkinson’s is in any way a ‘good thing’ - but perhaps those with advanced disease are not in themselves experiencing suffering.)