REBUS and the Anarchic Brain
Happy Friday! Saturday!
I write this from a car park near Trieste airport, where I'm waiting to pick up one of the steely thighed humans who will ride 680km from here to Dubrovnik this coming week. I am also being bitten to shreds by mosquitoes, an animal that indirectly kills over a million people a year.
We're lucky to be alive at all, really.
Since last week, I've done a lot of travelling, sleeping in hot rooms while thunder rolls around my head. Fat raindrops greeted me in Cherbourg, and spattered my carriage window as I rattled along the railways to Paris and Milan.
I will always defend slow travel over flight travel. Catching the ferry from Poole is an entirely calm experience, with the 'security' provided by a single gentleman who could have been an extra in Dad's Army. No stress and plenty of time to take photographs.
But the hours accumulated do take their toll. It's a shame that the Eurostar has adopted aggressive airline security because there is no doubt that the train is the most refreshing way to travel to and from the continent.
Nevertheless, 64 hours after leaving England, I met up with the rest of the Thighs of Steel core team in Trieste, and we drove out to stay in Dolnje Lezece, a village on the edge of the Škocjan Caves.
I'd love to tell you more about this world heritage site, but most of our time in the area was spent unpacking and cleaning Calypso, our support van.
One afternoon we picked our way down through the beech and pine woods on the sheer slopes of the gorge until we reach the river, pools of barely flowing water shrivelled from the summer sun. A long cold swim cured my travel-sore headaches.
So now the van is packed (albeit now also full of mosquitoes) and it is time to pick up the last of the cyclists. See you in Dubrovnik...
If you like this sort of thing, then you'll probably also like my back catalogue of over 500 posts, all found at davidcharles.info.
The only other thing that I'd like to do today is draw your attention to a very interesting new paper by Robin Carhart-Harris and Karl Friston.
REBUS and the Anarchic Brain is an attempt to model the brain action of psychedelics and neatly explains various phenomena related to the psychedelic experience, such as visual hallucinations.
But in the process, the authors propose the mechanism behind creative insights, the action and treatment of mental disorders, and quite possibly give us the key to unlock our better selves.
A sampler:
The present work proposes that a principal action of classic psychedelics is to relax the precision weighting of prior beliefs encoded in the spontaneous activity of neuronal hierarchies. ...
Functionally, the effect of relaxing the precision weighting of high-level priors is to create a state in which these priors are imbued with less confidence. As just touched on, an important example of a high-level prior is the belief that one has a particular personality and set of characteristics and views. ...
A corollary of relaxing high-level priors or beliefs under psychedelics is that ascending prediction errors from lower levels of the system (that are ordinarily unable to update beliefs due to the top-down suppressive influence of heavily-weighted priors) can find freer register in conscious experience, by reaching and impressing on higher levels of the hierarchy.
Under psychedelics, one can view global brain function as entering a mode or state that: 1) features a lightening or relaxation of the precision weighting on priors and 2) allows for a (potentially enduring) revision of such priors, via the release of prediction error that impacts on the sensitized priors.
It's well worth persevering with: the perfect reading material for a seven hour transcontinental train ride.
Much love, - dc
CREDITS
David Charles wrote this newsletter. David is co-writer of BBC Radio sitcom Foiled, and also writes for The Bike Project, Forests News, Elevate and Thighs of Steel. Reply to this email, or read more at davidcharles.info.