Can you explain the role of predictive brain processing in FND?

[Lady4]

The above question is one of the Q&A questions in the session with Professor Jon Stones Education session with us tonight.

I think prediction error plays a big part but stay tuned and I will update with his response.

Update:

Role of predictive brain processing:

“This is a powerful way of understanding brain conditions and FND and psychiatric conditions as well. We have to be careful with it as we don’t absolutely know if it is correct but there are lots of reasons to think that the brain works by predicting what is going to happen in the world around it. The brain hallucinates reality as an idea. When I pick up my phone, my brain knows roughly how much it weighs so I use the right amount of effort to do so. We used to think I sense the phone and then lift it up but now the brain is predicting in advance what is going to happen and that helps us understand a lot of things that would otherwise seem weird.

Phantom limb for example, the idea is you have a strong prediction that is saying there is a leg but that memory is so strong it overrides the sensation that it isn’t there. It overrides sensation. In FND in leg weakness, what has happened is the brain is strongly predicting the leg is weak or isn’t there.

[210272]

Good to see this question on the list for tonight

Here's a useful paper about the predictive brain model. It's not clearly defined (much like the term 'functional') and there are many controversies about it:

Abstract

It has been widely asserted that humans have a “Bayesian brain.” Surprisingly, however, this term has never been defined and appears to be used differently by different authors. I argue that Bayesian brain should be used to denote the realist view that brains are actual Bayesian machines and point out that there is currently no evidence for such a claim.

Type

Open Peer Commentary

Information

Behavioral and Brain Sciences , Volume 42 , 2019 , e238

DOI: doi.org/10.1017/S0140525X19...

[Lady4 in reply to 210272]

Hi, it was last night but I need to re-watch when recording loaded. He did reference leg weakness, the brains prediction is at a level thats its hard to reach - something like that (have a few gaps). Asked another member who seems good at note taking, to share re Predictions.

Couldn't read the full article so wondered what Bayesian computations are?

Also I must add that there was a question re how do you describe FND to your patients and he sais he explains what someone can is in front of them (person specific).

The hardware / software reference which I know you so love was explained in greater detail.

[210272 in reply to Lady4]

Good that you have some note takers to ask but as things move forwards I think Jon and his crew need to be offering full transcripts to take the pressure off the patient participants. Likewise they need to provide plain summaries of some of the constructs involved (which I think is what they are trying to do, but it's all somewhat clunky at the moment and may continue to be so until they have training in effective scientific communication). Baysian brain computations are top down (IE brain first) as far as I can tell which makes very little sense to me since there are so many external factors (brains not being closed systems) which come in at every level. EG atmospheric pressure changes can hike or trigger migraine symptoms without someone being aware that the pressure has changed although some of us think that we're better at predicting weather changes than most forecasters Also there are internal factors eg hormones that may act as neurotransmitters which don't seem to fall under the predictive brain model (most brain models not being designed by women) as far as I can tell. Maybe Jon can ask the FND Feminists for their take on all this. If he can get some of them to take turns to be members of this hub (so they can arrange suitable interventions when people lose the will to live, amongst other tasks) that would be cool.

A lot of these articles are behind paywalls but I just wanted people to be aware that there are controversies about the Bayesian brain theory.

They need to consider dropping that hardware/software analogy. Now we know it's used to align their language with ours when giving a FND dx it looks like medical gaslighting or hoodwinking and it is dehumanising. Our brains are not computers and conceptualising them as such could hold back research. Maybe a better and more honest explanation would be to say that the symptoms are, as yet, of unknown aetiology, but can respond positively to various therapy modalities so people see a meaningful improvement to their quality of life. However they also need to be honest about how hard it can be to access effective treatments, especially in under resourced health care systems.

I'd be very interested to know what Jon thinks (and what he thinks patients think) about 'hysteria' being one of the keywords in the latest hypothesis about FND. The good thing about it is that it's a hypothesis, unlike the Perez patient blaming/psychiatric labelling stuff. But as it stands the only positive thing I can say about it is 'oh wow. Two psychiatrists have managed to accurately identify an adjective.' The adjective being 'functional' which was chosen partly because it maps onto an understanding of modern imaging techniques, partly because it avoids a pointless discussion about brain and mind (hmm) and partly because it is 'easily used with patients'. Yeah, right

[Lady4]

Its not top down it works both ways 😊