PyramidHead
Contributor
If subjective experience is a matter of what is happening in the brain, then it seems that there may be a difference between the time that elapses for the brain itself and the time that elapses in subjective experience. I'm not talking about the psychological effect of feeling like a speech has gone on forever when it's only been 20 minutes, or 'time flies when you're having fun.' I'm talking about a more obvious difference, which can be illustrated by (surprise surprise) some thought experiments.
A simple one to imagine is that the you are living in a simulation. Your brain is being fed impulses by a machine programmed to exactly replicate whatever the brain would have received if you were navigating the actual world. The program is entirely artificial and will go the way it goes regardless of your conscious control, although it will feel as though you are making conscious choices at times because the corresponding neural patterns will be so activated at those points in the simulation. One afternoon, a technician on duty accidentally hits the "pause" button on her way out, and your brain state is kept in stable stasis at that line of code for the duration of the night. The next morning, noticing her mistake, she un-pauses the machine and the program continues normally.
It might be tempting to think that, when the "pause" button was hit, you suddenly became aware that you were lying down in a lab somewhere (or worse yet, a brain in a vat of chemicals), and were paralyzed in terror for the entire night. Yet, there is no reason to think that this is true, because if it were, your brain state would have changed accordingly, which is not possible given the stipulation that the machine keeps your brain signals static while "pause" is active. The only alternative, then, is that you wouldn't notice the change at all. Your subjective experience would be seamless and uninterrupted, even if there had been a year or a decade between pausing and un-pausing the machine. Do you agree so far?
Let me add a wrinkle to this thought experiment. For some unknown reason, your brain has been divided into four parts. Each part is in a separate room, and is being fed impulses by the same kinds of machines, only the machine for each quarter of your brain is optimized to feed it only the necessary signals that would have been naturally received by that part, were it connected to the others and were you actually out there in the real world. There is no connection whatsoever among the four quarters of your brain, but the signals they are receiving individually are exactly what they would be receiving if they were integrated physically.
The inescapable conclusion is that you would still not notice anything different in your subjective experience. If subjective experience is a function of brain activity, and brain activity is reducible to inputs and outputs, then a sufficiently detailed machine capable of replicating the inputs and outputs of isolated segments of your brain would be a perfect stand-in for the regular kind of interconnected activity of your brain while intact. Remember, the entire program of your experiences is already planned ahead of time, and the machines know just what signals they would have gotten from the other parts of your brain during these experiences, and are programmed to provide exactly those signals without being connected to the others. The four parts of your brain could be separated by miles, even located in different countries, and as long as the correct information were being fed to each one, your experience would be no different. Do you still agree?
When we combine the two scenarios, there is a further complication. Suppose the careless technician accidentally hit the "pause" button on the machine that sent impulses to just your front-left segment before leaving for the night. Elsewhere, perhaps across the ocean, the other three segments continue to receive information from their respective machines. What would your experience be like during the night? What would it be like the next morning when she un-paused the front-left segment's machine, thus making it about 14 hours "out of sync" with the others?
Surprisingly, if we are being consistent with the functional activity of the brain ( and nothing else) determining subjective experience, you would still not notice any change. After all, your brain would still be receiving just the same signals as it would have under ordinary circumstances. In every functional respect, every part of your brain would still have the same inputs and outputs as your intact brain would if you were actually awake and in the real world. Since the four machines in charge of sending signals to the four quarters of your brain were never connected to each other anyway, why should it matter the order in which they carry out their respective programs? In fact, each portion of your brain could be fed its entire sequence of impulses separately, with a month passing between the activation and deactivation of each one, and your experience would not feel any different from the inside.
In fact, the sequence of "events" in the simulation itself could be scrambled, so that the machines first provide the impulses you would have received tomorrow, followed by the ones you would have received yesterday, followed by the ones you would have received today. As long as those impulses exactly replicate every part of your experience (including memory and the internal sensations associated with the passage of time), it would still appear to you as though you had lived yesterday, then today, and then tomorrow.
A complete and perfect functional package of brain impulses, regardless of the objective timing, spatial location, and order in which its information is delivered, must therefore always be "stitched together" by subjective experience as a seamless package. This should give us compelling reason to doubt that there is anything absolute or reality-reflective in the way we subjectively experience time as constantly flowing.
A simple one to imagine is that the you are living in a simulation. Your brain is being fed impulses by a machine programmed to exactly replicate whatever the brain would have received if you were navigating the actual world. The program is entirely artificial and will go the way it goes regardless of your conscious control, although it will feel as though you are making conscious choices at times because the corresponding neural patterns will be so activated at those points in the simulation. One afternoon, a technician on duty accidentally hits the "pause" button on her way out, and your brain state is kept in stable stasis at that line of code for the duration of the night. The next morning, noticing her mistake, she un-pauses the machine and the program continues normally.
It might be tempting to think that, when the "pause" button was hit, you suddenly became aware that you were lying down in a lab somewhere (or worse yet, a brain in a vat of chemicals), and were paralyzed in terror for the entire night. Yet, there is no reason to think that this is true, because if it were, your brain state would have changed accordingly, which is not possible given the stipulation that the machine keeps your brain signals static while "pause" is active. The only alternative, then, is that you wouldn't notice the change at all. Your subjective experience would be seamless and uninterrupted, even if there had been a year or a decade between pausing and un-pausing the machine. Do you agree so far?
Let me add a wrinkle to this thought experiment. For some unknown reason, your brain has been divided into four parts. Each part is in a separate room, and is being fed impulses by the same kinds of machines, only the machine for each quarter of your brain is optimized to feed it only the necessary signals that would have been naturally received by that part, were it connected to the others and were you actually out there in the real world. There is no connection whatsoever among the four quarters of your brain, but the signals they are receiving individually are exactly what they would be receiving if they were integrated physically.
The inescapable conclusion is that you would still not notice anything different in your subjective experience. If subjective experience is a function of brain activity, and brain activity is reducible to inputs and outputs, then a sufficiently detailed machine capable of replicating the inputs and outputs of isolated segments of your brain would be a perfect stand-in for the regular kind of interconnected activity of your brain while intact. Remember, the entire program of your experiences is already planned ahead of time, and the machines know just what signals they would have gotten from the other parts of your brain during these experiences, and are programmed to provide exactly those signals without being connected to the others. The four parts of your brain could be separated by miles, even located in different countries, and as long as the correct information were being fed to each one, your experience would be no different. Do you still agree?
When we combine the two scenarios, there is a further complication. Suppose the careless technician accidentally hit the "pause" button on the machine that sent impulses to just your front-left segment before leaving for the night. Elsewhere, perhaps across the ocean, the other three segments continue to receive information from their respective machines. What would your experience be like during the night? What would it be like the next morning when she un-paused the front-left segment's machine, thus making it about 14 hours "out of sync" with the others?
Surprisingly, if we are being consistent with the functional activity of the brain ( and nothing else) determining subjective experience, you would still not notice any change. After all, your brain would still be receiving just the same signals as it would have under ordinary circumstances. In every functional respect, every part of your brain would still have the same inputs and outputs as your intact brain would if you were actually awake and in the real world. Since the four machines in charge of sending signals to the four quarters of your brain were never connected to each other anyway, why should it matter the order in which they carry out their respective programs? In fact, each portion of your brain could be fed its entire sequence of impulses separately, with a month passing between the activation and deactivation of each one, and your experience would not feel any different from the inside.
In fact, the sequence of "events" in the simulation itself could be scrambled, so that the machines first provide the impulses you would have received tomorrow, followed by the ones you would have received yesterday, followed by the ones you would have received today. As long as those impulses exactly replicate every part of your experience (including memory and the internal sensations associated with the passage of time), it would still appear to you as though you had lived yesterday, then today, and then tomorrow.
A complete and perfect functional package of brain impulses, regardless of the objective timing, spatial location, and order in which its information is delivered, must therefore always be "stitched together" by subjective experience as a seamless package. This should give us compelling reason to doubt that there is anything absolute or reality-reflective in the way we subjectively experience time as constantly flowing.
