spxtr comments on $250 prize for checking Jake Cannell’s Brain Efficiency

[spxtr]

Hi Alexander,

I would be happy to discuss the physics related to the topic with others. I don’t want to keep repeating the same argument endlessly, however.

Note that it appears that EY had a similar experience of repeatedly not having their point addressed:

I’m confused at how somebody ends up calculating that a brain—where each synaptic spike is transmitted by ~10,000 neurotransmitter molecules (according to a quick online check), which then get pumped back out of the membrane and taken back up by the synapse; and the impulse is then shepherded along cellular channels via thousands of ions flooding through a membrane to depolarize it and then getting pumped back out using ATP, all of which are thermodynamically irreversible operations individually—could possibly be within three orders of magnitude of max thermodynamic efficiency at 300 Kelvin. I have skimmed “Brain Efficiency” though not checked any numbers, and not seen anything inside it which seems to address this sanity check.

Then, after a reply:

This does not explain how thousands of neurotransmitter molecules impinging on a neuron and thousands of ions flooding into and out of cell membranes, all irreversible operations, in order to transmit one spike, could possibly be within one OOM of the thermodynamic limit on efficiency for a cognitive system (running at that temperature).

Then, after another reply:

Nothing about any of those claims explains why the 10,000-fold redundancy of neurotransmitter molecules and ions being pumped in and out of the system is necessary for doing the alleged complicated stuff.

Then, nothing more (that I saw, but I might have missed comments. this is a popular thread!).

:), spxtr