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But knowing that still doesn't bring you that much closer to simulating it. There's a couple a of great papers where they got biologists to attempt to figure ou

But knowing that still doesn't bring you that much closer to simulating it. There's a couple a of great papers where they got biologists to attempt to figure out how relatively simple, very well known things worked - one was a radio[1], one was an old Atari chip[2]. So they used biological techniques used to try to figure out how brains worked. For example lesions - they took transistors out of the arcade machine and tested if the game still started up. And if, say, they found that taking a and b out stopped Donkey Kong from working, and x and y stopped space invaders working, then maybe they could make the assumption that a and b were the Donkey Kong transistors, etc. Or if they destroyed tiny parts of the radio circuit board and it still appeared to work, then those parts were junk, unnecessary. But of course that's completely misleading. It doesn't matter how much data they had either. It's not to say the data that is currently held isn't important; it is, but it doesn't then translate to 'we can model this insanely complex system', because there's so, so much missing from the understanding of how it works [1] https://www.cmu.edu/biolphys/deserno/pdf/can_a_biologist_fix_a_radio.pdf https://www.cmu.edu/biolphys/deserno/pdf/can_a_biologist_fix... [2] http://biorxiv.org/content/biorxiv/early/2016/05/26/055624.full.pdf http://biorxiv.org/content/biorxiv/early/2016/05/26/055624.f...

intrasight 10y ago
It's just as revealing to have an engineer try to understand a living thing. There's a huge cultural and language gap between the disciplines.
- regularfry 10y ago
  Apparently opticians can spot an engineer a mile off because they think of the eye as a simple lens system. It's not.
merastius 10y ago
This, and our failure to simulate something as well understood as the c. elegans' 302 neurons, makes me think that biologists need to push a new approach. When it comes to understanding a radio or a microchip, my first instinct would be to try to isolate components which are as small as possible, and actually try to map inputs to outputs... And if that's not working, either the component isn't small/basic enough, or I haven't really captured all the inputs. I'd hopefully start getting an idea about logic gates and voltage thresholds and eventually building up to larger and more complex processes and parts. 1) Would such an approach work in theory for a radio or chip? 2) I'm assuming I'm not the first person to think of this - is that approach basically what's already being done? (edit: a lot of stuff in this seem to be along those line: https://en.wikipedia.org/wiki/Electrophysiology https://en.wikipedia.org/wiki/Electrophysiology ) 3) Is it just much harder than I imagine to isolate a single neuron (or small set of neurons) and try some inputs to come up with the algorithm to properly simulate it? 4) Or are neurons too complex for this approach to be effective, and we need to dig down to more basic components or get a better understanding of inputs?
- regularfry 10y ago
  It's 4. Biological neurons are much more complex than they appear: they're sensitive to many, many different chemical signals, they have internal structure that's non-trivial, and they can have not just excitatory/inhibitory outputs, but modulatory as well. It's hard to know how to even start extracting subcomponents.
- marcosdumay 10y ago
  Biological systems are a tangled mess where everything interacts with everything else, and anything that goes in also goes out, and the other way around.

intrasight 10y ago

It's just as revealing to have an engineer try to understand a living thing. There's a huge cultural and language gap between the disciplines.

regularfry 10y ago
Apparently opticians can spot an engineer a mile off because they think of the eye as a simple lens system. It's not.

merastius 10y ago

This, and our failure to simulate something as well understood as the c. elegans' 302 neurons, makes me think that biologists need to push a new approach. When it comes to understanding a radio or a microchip, my first instinct would be to try to isolate components which are as small as possible, and actually try to map inputs to outputs... And if that's not working, either the component isn't small/basic enough, or I haven't really captured all the inputs. I'd hopefully start getting an idea about logic gates and voltage thresholds and eventually building up to larger and more complex processes and parts. 1) Would such an approach work in theory for a radio or chip? 2) I'm assuming I'm not the first person to think of this - is that approach basically what's already being done? (edit: a lot of stuff in this seem to be along those line: https://en.wikipedia.org/wiki/Electrophysiology https://en.wikipedia.org/wiki/Electrophysiology ) 3) Is it just much harder than I imagine to isolate a single neuron (or small set of neurons) and try some inputs to come up with the algorithm to properly simulate it? 4) Or are neurons too complex for this approach to be effective, and we need to dig down to more basic components or get a better understanding of inputs?

regularfry 10y ago
It's 4. Biological neurons are much more complex than they appear: they're sensitive to many, many different chemical signals, they have internal structure that's non-trivial, and they can have not just excitatory/inhibitory outputs, but modulatory as well. It's hard to know how to even start extracting subcomponents.
marcosdumay 10y ago
Biological systems are a tangled mess where everything interacts with everything else, and anything that goes in also goes out, and the other way around.