The Mathematics of Consciousness

this video is brought to you by the great courses plus stick around for more information about them later physicists like to think they can explain everything and that of course includes human consciousness and so in the last few decades they've set out to demystify the brain by throwing math at the problem last year i attended a workshop on the mathematics of consciousness in oxford back then when we still met other people in real life remember that i find it to be a really interesting development that physicists take on consciousness and so today i want to talk a little about ideas for how consciousness can be described mathematically how that's going so far and what we can hope to learn from it in the future [Music] the currently most popular mathematical approach to consciousness is integrated information theory iit for short it was put forward by a neurologist giolio tunini in 2004. in iit each system has assigned a number that's big phi which is the integrated information and supposedly a measure of consciousness the better system is at distributing information while it's processing the information the larger phi a system that's fragmented and has many parts that calculate in isolation may process lots of information but this information is not integrated so phi is small for example a digital camera has millions of light receptors it processes large amounts of information but the parts of the system don't work much together so phi is small the human brain on the other hand is very well connected and neural impulses constantly travel from one part to another so phi is large at least that's the idea but iit has its problems one problem with iit is that computing phi is ridiculously time consuming the calculation requires that you divide up the system which you are evaluating in any possible way and then calculate the connections between the parts this takes up an enormous amount of computing power estimates show that even for the brain of a worm with only 300 synapses calculating phi would take several billion years this is why measurements of phi that have actually been done in the human brain have used incredibly simplified definitions of integrated information do these simplified definitions at least correlate with consciousness well some studies have claimed they do then again others have claimed they don't the magazine new scientist for example interviewed daniel bohr from the university of cambridge and reports fight should decrease when you go to sleep or are sedated by your general anaesthetic for instance but work in bohr's lab has shown that it doesn't it either goes up or stays the same he says i contacted bohr and his group but they wouldn't come forward with evidence to back up this claim i do not actually doubt it's correct but i do find it somewhat peculiar they'd make such a statement to a journalist and then not provide evidence for it yet another problem for iit is as the computer scientist scott aronson pointed out that one can think of rather trivial systems that solve some mathematical problem which distribute information during the calculation in such a way that phi becomes very large this demonstrates that phi in general says nothing about consciousness and in my opinion this just kills the idea nevertheless integrated information theory was much discussed at the oxford workshop another topic that received a lot of attention is the idea by roger penrose and stuart hameroff that consciousness arises from quantum effects in the human brain not in synopses but in microtubules what the heck are microtubules microtubules are tiny tubes made of proteins that are present in most cells including neurons according to penrose and hammeroff in the brain these microtubules can enter coherent quantum states which collapse every once in a while and consciousness is created in that collapse most physicists me included are not terribly excited about this idea because it's generally hard to create coherent quantum states of fairly large molecules and it doesn't help if you put these molecules into a warm and wiggly environment like the human brain for the penrose and hammer of conjecture to work the quantum state would have to survive at least a microsecond or so but the physicist max tickmark has estimated that they would last more like a femtosecond that's only 10 to the minus 15 seconds penrose and hammeroff are not the only ones who pursue the idea that quantum mechanics has something to do with consciousness the physicist tim palmer also thinks there's something to it though he's more concerned with the origins of creativity specifically than with consciousness in general according to palmer quantum fluctuations in the human brain create noise and that noise is essential for human creativity because it can help us when a deterministic analytical approach gets stuck he believes the sensitivity to quantum fluctuations developed in the human brain because that's the most energy efficient way of solving problems but it only becomes possible once you have small and thin neurons of the type you find in the human brain therefore palmer has argued that low energy transistors which operate probabilistically rather than deterministically might help us develop artificial intelligence that's actually intelligent another talk that i thought was interesting at the oxford workshop was that by ramon era one of the leading hypotheses for how cognitive processing works is that it uses the synchronization of neural activity in different regions of the brain to integrate information but era points out that during an epileptic seizure different parts of the brain are highly synchronized even though the patient is not conscious in this figure for example you see the correlations between the measured activity of 150 or so brain sites red is correlated blue is uncorrelated on the left is the brain during a normal conscious phase on the right is a seizure so clearly too much synchronization is not a good thing error has therefore proposed that a measure of consciousness could be the entropy and the correlation matrix of the synchronization which is low both for highly uncorrelated and highly correlated states but large in the middle where you expect consciousness however i worry that this idea has the same problem as integrated information theory which is that there may be very simple systems that you do not expect to be conscious that nevertheless score very highly on this simple measure of synchronization one final talk that i would like to mention is that by jonathan mason he asks us to imagine a stack of compact disks and a disk player that doesn't know which order to read out the bits on a compact disk for the first disk you then can always find a readout order that will result in a particular bit sequence that could correspond for example to your favorite song but if you then use that same readout order for the next disc you most likely just get noise which means there's very little information in the signal so if you have no idea how to read out information from the disks what would you do you'd look for a readout process that maximizes the information or minimizes the entropy for the readout result for all of the disks mason argues that the brain uses a similar principle of entropy minimization to make sense of information personally i think all of these approaches are way too simple to be correct in the best case their first steps on a long way but as they say every journey starts with a first step and i certainly hope that in the next decade we will learn more about just what it takes to create consciousness this might not only allow us to create artificial consciousness and help us tell when patients who can't communicate are conscious it might also allow us to make sense of the unconscious part of our thoughts so that we can become more conscious of them you can find recordings of all the talks at the workshop right here on youtube please check the info below the video for references this video was sponsored by the great courses plus i have learned a lot on youtube but it's hard to find well-structured content here when it comes to online learning i have found the great courses plus to be much more useful the great courses plus is a subscription on demand video learning platform that allows you to stream lectures on your browser or using an app on your phone it's kind of like netflix for learning they have more than 11 000 video lectures from recognized experts about whatever it is that you're interested in from science and math to linguistics to cooking and while we were stuck at home during the lockdowns i have particularly enjoyed their content about far away countries the great courses plus now offers a free trial for viewers of this channel which is a double benefit because it both serves your curiosity and supports this channel to make use of this offer please visit thegreatcoursesplus.com zabina that's 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Channel: Sabine Hossenfelder

Views: 284,646

Keywords: what is consciousness, consciousness, mathematics, physics, mathematics of consciousness, can mathematics explain consciousness, integrated information theory, hossenfelder, penrose, hameroff, brain, is the brain physics, physics of the brain, physics of consciousness, science without the gobbledygook

Id: efVBUDnD_no

Length: 11min 1sec (661 seconds)

Published: Sat Jan 09 2021

Reddit Comments

[u/basically_alive]

amazed they got a pic of my mom when she looks in my fridge for the thumbnail

[u/hexachoron]

Theoretical physicist Sabine Hossenfelder discusses mathematical approaches to describing consciousness in physics, including Integrated Information Theory, quantum effects in microtubules, Quantum Creativity, and more.

[u/Digitalapathy]

Thanks for posting, it’s an interesting summary but she doesn’t appear to be adding much to the subject. Given it’s one of our last frontiers of understanding scientists have to go out there with theories to move the field forward, it’s highly probable that we won’t make significant breakthroughs in any of our lifetimes. I’m also not convinced we will ever have a strong artificial consciousness, it’s a massive over simplification of what consciousness is IMHO.

[u/teafuck]

The breakdown of some of these theories where seemingly unconscious systems are described as being conscious due to connectivity can be smoothed over by accepting the possibility of panpsychism, or at least keeping an open mind about what is or isn't conscious. Not that I've found any great evidence for panpsychism outside of an acid trip.

[u/Rocky87109]

Here's her wiki if anyone wants a brief overview:

https://en.wikipedia.org/wiki/Sabine_Hossenfelder

[u/Felix_Orion]

Sabine Hossenfelder I'd fucking awesome, room mate tipped me off about this video earlier, thanks for spreading the good word.