On a related note, is anyone familiar with the following variation on the fading qualia argument? It’s inspired by (and very similar to) a response to Chalmers given in the paper “Counterfactuals Cannot Count” by M. Bishop. (Unfortunately, I couldn’t find an ungated version.) Chalmers’s reply to Bishop is here.
The idea is as follows. Let’s imagine a though experiment under the standard computationalist assumptions. Suppose you start with an electronic brain B1 consisting of a huge number of artificial neurons, and you let it run for a while from some time T1 to T2 with an input X, so that during this interval, the brain goes through a vivid conscious experience full of colors, sounds, etc. Suppose further that we’re keeping a detailed log of each neuron’s changes of state during the entire period. Now, if we reset the brain to the initial state it had at T1 and start it again, giving it the same input X, it should go through the exact same conscious experience.
But now imagine that we take the entire execution log and assemble a new brain B2 precisely isomorphic to B1, whose neurons are however not sensitive to their inputs. Instead, each neuron in B2 is programmed to recreate the sequence of states through which its corresponding neuron from B1 passed during the interval (T1, T2) and generate the corresponding outputs. This will result in what Chalmers calls a “wind-up” system, which the standard computationalist view (at least to my knowledge) would not consider conscious, since it completely lacks the causal structure of the original computation, and merely replays it like a video recording.
You can probably see where this is going now. Suppose we restart B1 with the same initial state from T1 and the same input X, and while it’s running, we gradually replace the neurons from B1 with their “wind-up” versions from B2. At the start at T1, we have the presumably conscious B1, and at the end at T2, the presumably unconscious B2 -- but the transition between the two is gradual just like in the original fading qualia argument. Thus, there must be some sort of “fading qualia” process going on after all, unless either B1 is not conscious to begin with, or B2 is conscious after all. (The latter however gets us into the problem that every physical system implements a “wind-up” version of every computation if only some numbers from arbitrary physical measurements are interpreted suitably.)
I don’t find Chalmers’s reply satisfactory. In particular, it seems to me that the above argument is damaging for significant parts of his original fading qualia thought experiment where he explains why he finds the possibility of fading qualia implausible. It is however possible that I’ve misunderstood either the original paper or his brief reply to Bishop, so I’d definitely like to see him address this point in more detail.
Bishop responds that mere counterfactual sensitivity can’t make a difference to consciousness: surely it’s what actually happens to a system that matters, not what would have happened if things had gone differently
This is a false distinction if (as I believe) counterfactual sensitivity is part of what happens. For example, if what happens is that Y causes Z, then part of that is the counterfactual fact that if Y hadn’t happened then Z wouldn’t have happened. (Maybe this particular example can be nitpicked, but I hope that the fundamental point is made.)
Thus, there must be some sort of “fading qualia” process going on after all, unless either B1 is not conscious to begin with, or B2 is conscious after all.
If counterfactual sensitivity matters—and I think it does—then some sort of fading (I hesitate to call it “fading qualia” specifically—the whole brain is fading, in that its counterfactual sensitivity is gradually going kaput) is going on. And since the self is (by hypothesis) unable to witness what’s happening, then this demonstrates how extreme our corrigibility with regard to our own subjective experiences is. Not at all a surprising outcome.
I think that something like this must be the case. Especially considering the hypothesis that the brain is a dynamical system that requires rapid feedback among a wide variety counterfactual channels, even the type of calculation in Simplicio’s simulation model wouldn’t work. Note that this is not just because you don’t have enough time to simulate all the moves of the computer algorithm that produces the behavior. You have to be ready to mimic all the possible behaviors that could arise from a different set of inputs, in the same temporal order. I’m sure that somewhere along the way, linear methods of calculation such as your simulation attempts, must break down.
In other words, your simulation is just a dressed up version of the wind up system from a dynamical system point of view. The analogy runs like this: The simulation model is to the real consciousness what the wind-up model is to a simulation, in that it supports much fewer degrees of freedom. It seems that you have to have the right kind of hardware to support such processes, hardware that probably has criteria much closer to our biological, multilateral processing channels than a linear binary logic computer. Note that even though Turing machines supposedly can represent any kind of algorithm, they cannot support the type of counterfactual channels and especially feedback loops necessary for consciousness. The number of calculations necessary to recreate the physical process is probably beyond the linearly possible with such apparatuses.
This puts the computed human in a curious position in as much as she must consider, if philosophising about her existence, whether she is a reductionist version of a ‘deceptive demon’ that (even more) mystically oriented philosophers have been want to consider. Are her neurons processing stimulus or controlled by their own pattern?
On the other hand she does have some advantages. Because her neuron’s responses are initially determined stimulus X and her own cognitive architecture she is free to do whatever experiments are possible within the artificial world X. X will then either present her with a coherent world of the sort humans would be able to comprehend or present her with something that more or less befuddles her mind. After doing experiments to determine how her brain seems to work she knows that either things are what they appear or that the deceptively demonic computationalist overlords are messing with her electronic brain (or potentially any other form of processing). Either by giving her bogus X or making her entire state totally arbitrary. Throw in Boltzman brains as equivalent to ‘computationalist overlords’ too, as far as she is concerned.
I don’t know what points Chalmer’s or Bishop were trying to make about ‘qualia’ because such arguments often make little to no sense to me. This scenario (like most others) looks like just another curious setup in a reductionist universe.
On a related note, is anyone familiar with the following variation on the fading qualia argument? It’s inspired by (and very similar to) a response to Chalmers given in the paper “Counterfactuals Cannot Count” by M. Bishop. (Unfortunately, I couldn’t find an ungated version.) Chalmers’s reply to Bishop is here.
The idea is as follows. Let’s imagine a though experiment under the standard computationalist assumptions. Suppose you start with an electronic brain B1 consisting of a huge number of artificial neurons, and you let it run for a while from some time T1 to T2 with an input X, so that during this interval, the brain goes through a vivid conscious experience full of colors, sounds, etc. Suppose further that we’re keeping a detailed log of each neuron’s changes of state during the entire period. Now, if we reset the brain to the initial state it had at T1 and start it again, giving it the same input X, it should go through the exact same conscious experience.
But now imagine that we take the entire execution log and assemble a new brain B2 precisely isomorphic to B1, whose neurons are however not sensitive to their inputs. Instead, each neuron in B2 is programmed to recreate the sequence of states through which its corresponding neuron from B1 passed during the interval (T1, T2) and generate the corresponding outputs. This will result in what Chalmers calls a “wind-up” system, which the standard computationalist view (at least to my knowledge) would not consider conscious, since it completely lacks the causal structure of the original computation, and merely replays it like a video recording.
You can probably see where this is going now. Suppose we restart B1 with the same initial state from T1 and the same input X, and while it’s running, we gradually replace the neurons from B1 with their “wind-up” versions from B2. At the start at T1, we have the presumably conscious B1, and at the end at T2, the presumably unconscious B2 -- but the transition between the two is gradual just like in the original fading qualia argument. Thus, there must be some sort of “fading qualia” process going on after all, unless either B1 is not conscious to begin with, or B2 is conscious after all. (The latter however gets us into the problem that every physical system implements a “wind-up” version of every computation if only some numbers from arbitrary physical measurements are interpreted suitably.)
I don’t find Chalmers’s reply satisfactory. In particular, it seems to me that the above argument is damaging for significant parts of his original fading qualia thought experiment where he explains why he finds the possibility of fading qualia implausible. It is however possible that I’ve misunderstood either the original paper or his brief reply to Bishop, so I’d definitely like to see him address this point in more detail.
Well, this bit seems wrong on Bishop’s part:
This is a false distinction if (as I believe) counterfactual sensitivity is part of what happens. For example, if what happens is that Y causes Z, then part of that is the counterfactual fact that if Y hadn’t happened then Z wouldn’t have happened. (Maybe this particular example can be nitpicked, but I hope that the fundamental point is made.)
If counterfactual sensitivity matters—and I think it does—then some sort of fading (I hesitate to call it “fading qualia” specifically—the whole brain is fading, in that its counterfactual sensitivity is gradually going kaput) is going on. And since the self is (by hypothesis) unable to witness what’s happening, then this demonstrates how extreme our corrigibility with regard to our own subjective experiences is. Not at all a surprising outcome.
I think that something like this must be the case. Especially considering the hypothesis that the brain is a dynamical system that requires rapid feedback among a wide variety counterfactual channels, even the type of calculation in Simplicio’s simulation model wouldn’t work. Note that this is not just because you don’t have enough time to simulate all the moves of the computer algorithm that produces the behavior. You have to be ready to mimic all the possible behaviors that could arise from a different set of inputs, in the same temporal order. I’m sure that somewhere along the way, linear methods of calculation such as your simulation attempts, must break down.
In other words, your simulation is just a dressed up version of the wind up system from a dynamical system point of view. The analogy runs like this: The simulation model is to the real consciousness what the wind-up model is to a simulation, in that it supports much fewer degrees of freedom. It seems that you have to have the right kind of hardware to support such processes, hardware that probably has criteria much closer to our biological, multilateral processing channels than a linear binary logic computer. Note that even though Turing machines supposedly can represent any kind of algorithm, they cannot support the type of counterfactual channels and especially feedback loops necessary for consciousness. The number of calculations necessary to recreate the physical process is probably beyond the linearly possible with such apparatuses.
Allenwang voted up—I don’t understand why there was a negative reaction to this.
This puts the computed human in a curious position in as much as she must consider, if philosophising about her existence, whether she is a reductionist version of a ‘deceptive demon’ that (even more) mystically oriented philosophers have been want to consider. Are her neurons processing stimulus or controlled by their own pattern?
On the other hand she does have some advantages. Because her neuron’s responses are initially determined stimulus X and her own cognitive architecture she is free to do whatever experiments are possible within the artificial world X. X will then either present her with a coherent world of the sort humans would be able to comprehend or present her with something that more or less befuddles her mind. After doing experiments to determine how her brain seems to work she knows that either things are what they appear or that the deceptively demonic computationalist overlords are messing with her electronic brain (or potentially any other form of processing). Either by giving her bogus X or making her entire state totally arbitrary. Throw in Boltzman brains as equivalent to ‘computationalist overlords’ too, as far as she is concerned.
I don’t know what points Chalmer’s or Bishop were trying to make about ‘qualia’ because such arguments often make little to no sense to me. This scenario (like most others) looks like just another curious setup in a reductionist universe.