The Nonlinear Library LW - 8 examples informing my pessimism on uploading without reverse engineering by Steven Byrnes
Nov 3, 2023
20:12
Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: 8 examples informing my pessimism on uploading without reverse engineering, published by Steven Byrnes on November 3, 2023 on LessWrong.
(If you've already read everything I've written, you'll find this post pretty redundant. See especially my old posts
Building brain-inspired AGI is infinitely easier than understanding the brain
, and
Randal Koene on brain understanding before whole brain emulation
, and
Connectomics seems great from an AI x-risk perspective
. But I'm writing it anyway mainly in response to
this post from yesterday
.)
1. Background / Context
1.1 What does uploading (a.k.a. Whole Brain Emulation (WBE)) look like with and without reverse-engineering?
There's a view that I seem to associate with
Davidad
and
Robin Hanson
, along with a couple other people I've talked to privately. (But I could be misunderstanding them and don't want to put words in their mouths.) The view says: if we want to do WBE, we do
not
need to reverse-engineer the brain.
For an example of what "reverse-engineering the brain" looks like, I can speak from abundant experience: I often spend all day puzzling over random questions like:
Why are there oxytocin receptors in certain mouse auditory cortex neurons?
Like, presumably Evolution put those receptors there for a reason - I don't think that's the kind of thing that appears randomly, or as an incidental side-effect of something else. (Although that's always a hypothesis worth considering!) Well, what is that reason? I.e., what are those receptors doing to help the mouse survive, thrive, etc., and how are they doing it?
…And once I have a working hypothesis about that question, I can move on to hundreds or even thousands more "why and how" questions of that sort. I seem to find the activity of answering these questions much more straightforward and tractable (and fun!) than do most other people - you can decide for yourself whether I'm unusually good at it, or deluded.
For an example of what uploading
without
reverse-engineering would look like, I think it's the idea that we can figure out the input-output relation of each neuron, and we can measure how neurons are connected to each other, and then at the end of the day we can simulate a human brain doing whatever human brains do.
Here's Robin Hanson arguing for the non-reverse-engineering perspective in
Age of Em
:
The brain does not just happen to transform input signals into state changes and output signals; this transformation is the primary function of the brain, both to us and to the evolutionary processes that designed brains. The brain is designed to make this signal processing robust and efficient. Because of this, we expect the physical variables (technically, "degrees of freedom") within the brain that encode signals and signal-relevant states, which transform these signals and states, and which transmit them elsewhere, to be overall rather physically isolated and disconnected from the other far more numerous unrelated physical degrees of freedom and processes in the brain. That is, changes in other aspects of the brain only rarely influence key brain parts that encode mental states and signals.
We have seen this disconnection in ears and eyes, and it has allowed us to create useful artificial ears and eyes, which allow the once-deaf to hear and the once-blind to see. We expect the same to apply to artificial brains more generally. In addition, it appears that most brain signals are of the form of neuron spikes, which are especially identifiable and disconnected from other physical variables.
If technical and intellectual progress continues as it has for the last few centuries, then within a millennium at the most we will understand in great detail how individual brain cells encode, transform, and transmit signals. This understanding should allow us to directly read rele...
(If you've already read everything I've written, you'll find this post pretty redundant. See especially my old posts
Building brain-inspired AGI is infinitely easier than understanding the brain
, and
Randal Koene on brain understanding before whole brain emulation
, and
Connectomics seems great from an AI x-risk perspective
. But I'm writing it anyway mainly in response to
this post from yesterday
.)
1. Background / Context
1.1 What does uploading (a.k.a. Whole Brain Emulation (WBE)) look like with and without reverse-engineering?
There's a view that I seem to associate with
Davidad
and
Robin Hanson
, along with a couple other people I've talked to privately. (But I could be misunderstanding them and don't want to put words in their mouths.) The view says: if we want to do WBE, we do
not
need to reverse-engineer the brain.
For an example of what "reverse-engineering the brain" looks like, I can speak from abundant experience: I often spend all day puzzling over random questions like:
Why are there oxytocin receptors in certain mouse auditory cortex neurons?
Like, presumably Evolution put those receptors there for a reason - I don't think that's the kind of thing that appears randomly, or as an incidental side-effect of something else. (Although that's always a hypothesis worth considering!) Well, what is that reason? I.e., what are those receptors doing to help the mouse survive, thrive, etc., and how are they doing it?
…And once I have a working hypothesis about that question, I can move on to hundreds or even thousands more "why and how" questions of that sort. I seem to find the activity of answering these questions much more straightforward and tractable (and fun!) than do most other people - you can decide for yourself whether I'm unusually good at it, or deluded.
For an example of what uploading
without
reverse-engineering would look like, I think it's the idea that we can figure out the input-output relation of each neuron, and we can measure how neurons are connected to each other, and then at the end of the day we can simulate a human brain doing whatever human brains do.
Here's Robin Hanson arguing for the non-reverse-engineering perspective in
Age of Em
:
The brain does not just happen to transform input signals into state changes and output signals; this transformation is the primary function of the brain, both to us and to the evolutionary processes that designed brains. The brain is designed to make this signal processing robust and efficient. Because of this, we expect the physical variables (technically, "degrees of freedom") within the brain that encode signals and signal-relevant states, which transform these signals and states, and which transmit them elsewhere, to be overall rather physically isolated and disconnected from the other far more numerous unrelated physical degrees of freedom and processes in the brain. That is, changes in other aspects of the brain only rarely influence key brain parts that encode mental states and signals.
We have seen this disconnection in ears and eyes, and it has allowed us to create useful artificial ears and eyes, which allow the once-deaf to hear and the once-blind to see. We expect the same to apply to artificial brains more generally. In addition, it appears that most brain signals are of the form of neuron spikes, which are especially identifiable and disconnected from other physical variables.
If technical and intellectual progress continues as it has for the last few centuries, then within a millennium at the most we will understand in great detail how individual brain cells encode, transform, and transmit signals. This understanding should allow us to directly read rele...