Archive for September 11th, 2016

Quote note (#283)

Peter Watts on the neurology of psychological integrity:

This thing you think of as you: it spreads across two cerebral hemispheres connected by the corpus callosum, a fat meaty pipe more than 200 million axons thick. Suppose I took a cleaver to that pipe, split it down the middle. (That’s no mere thought experiment: severing the corpus callosum is a last-ditch measure against certain forms of epilepsy.) In the wake of such violent separation, each hemisphere would go its own way. It would develop its own tastes in clothes, music, even its own religious beliefs. […] … Even when the corpus callosum is severed, the hemispheres can communicate via the brainstem. It’s a longer route, though, and a much thinner pipe: think dial-up versus broadband. The essential variables, once again, are latency and bandwidth. When the pipe is intact, signals pass back and forth across the whole brain fast enough for the system to act as an integrated whole, to think of itself as I. But when you force those signals to take the scenic route – worse, squeeze them through a straw – the halves fall out of sync, lose their coherence. I shatters into we. […] You might expect that an established personality, built over a lifetime and then split down the middle, might take some time to develop into distinct entities. Yet hemispheric isolation can also be induced chemically, by anaesthetising half the brain – and the undrugged hemisphere, unshackled from its counterpart, sometimes manifests a whole new suite of personality traits right on the spot. …

(There’s much more in the article.)

September 11, 2016admin 61 Comments »