Cracking the Brain’s Codes
technologyreview.com
technologyreview.com
If you're a bio-hacker with a penchant for hardware upgrades, I think that you don't need to wait for anyone to discover "the encoding" to install an interface to your mind. Just do it, and like everything else in your brain, you'll spend a few weeks training your mind to use the new sense and digital motor skills. Bio-feedback technology is already here.
Meanwhile, preparing experiments for creatures not yet alive is an altogether different game. Growing a structure, by controlling chemical pathways, or physically restricting the movement of neurons trained or genetically modified to fire according to pre-defined external stimuli seems to be what the article is driving at. But what good will that do me, if I'm already alive? Maybe a tiny lobotomy for me, and then drop in a blob vat grown cells, that brain slug their way into place? Would I still be me after that?
Would it be like trying to mend a spinal cord injury, which we still haven't quite mastered? Or since it would be surgery, would the brain take to it like rejoined pieces of healthy brain tissue, after the removal of a malignant tumor? I suppose a lot of that would depend on the quality of the custom grown tissue, and the technique of the operation.
Either way, nerve cells are essentially highly specialized finicky amoeba, with dendrites acting as elaborately decorated pseudopods. They don't quite "swim" like white blood cells, but sort of creep along, and test each other out, delicately and selectively. And apparantly human cells can specialize to the point where a single cell can recognize key concepts of individualized external human identities (the article mentions Jennifer Aniston and Luke Skywalker).
So, in the sense that dendrites are pseudopods, and pseudopods are, along their external surface, celluar membranes (lipid bi-layers, decorated with embedded proteins), the proteins are the specialized structures that ultimately drive the behavior of the cell to direct it's psuedopods this way or that way. It's a mixture of chemical reactions all the way down, even if there is a layer of very fundamental electrical processes mixed in, due to the deliberately maintained PH value, and shifting electrolytic potential of the chemicals involved.
There was an article describing brain behavior as analogous to a swarm of ants. This makes sense, since ant communities guide their collective behavior by tagging their territories with scent, which gets reinforced with increased ants marching along pathways. So, at the end of the day, some kind of transplant process would probably require an arm of research tackling the micro-scale and nano-scale structures and living behavior of the tissue, but also the chemical aspects of how neurons sniff each other out, and decide to stimulate each other through the electric polarity fluctuations of their electrolyte juices.
I am not aware of any evidence that this is the case. (That is not to say that I think the two are unrelated, I just think this assumption ought to be challenged, rather than taken for granted).
It's not assumption that there is nothing more to the mind than the material brain. This is based on very strong empirical evidence.
We have about 100 years worth of Neuroscience.
We also have fundamental physics and laws of chemistry. There is no reason or evidence to believe that something magical is happening in the brain, or that somehow particles which behave according to the laws of physics outside of the brain, somehow don't, when part of the brain. We have a very good understanding of all the fundamental forces that govern the physics of our everyday experience.
> I just think this assumption ought to be challenged, rather than taken for granted
Challenge it then. What is your reason to believe the laws of physics are broken in the brain or that the mind is more than the material brain? Is there even one shred of evidence for that?
There's a fascinating course on this topic available from The Great Courses:
http://www.thegreatcourses.com/tgc/courses/course_detail.asp...
Could you point me to some of this evidence?
Even the article says :
We know that many different molecular processes are involved, but we still know little about which synapses are modified and when, and almost nothing about how to work backward from a neural connectivity diagram to the particular memories encoded.
> What is your reason to believe the laws of physics are broken in the brain or that the mind is more than the material brain? Is there even one shred of evidence for that?
I am not saying its breaking any laws of physics. As far as I am aware the laws of physics do not apply to the conscious. I can't observe it. I can't touch it. It doesn't seem to be a physical entity as far as I can deduce. Can you measure consciousness (I am not referring to brain activity)?
Whats your reason for assuming that the conscious self is a result of the laws of physics?
The article doesn't say what you think it says.
We don't understand how consciousness works, but we're pretty confident that we can constrain the ultimate answer to being compatible with the known laws of physics. There's no good reason to believe anything otherwise.
>As far as I am aware the laws of physics do not apply to the conscious.
Woah. In what way? I'm not saying that we'll use the nomenclature and terminology of particle physics or field theory to describe consciousness when (if ever) we understand it, just like we don't when we explain how weather or even biological processes work, but it damn well better square with particle physics.
>Whats your reason for assuming that the conscious self is a result of the laws of physics?
It comes down to the following: The current fundamental physics are incredibly successful in modeling particle and field interactions in pretty much every domain we studied them under, certainly in every domain that we as humans interact with. Even though we may not understand how consciousness arises from a material brain, it is a huge leap in logic to segregate that particular domain and say that this one part of our world is not (in principle) explainable by our physics, because the laws of physics do not share that distinction. You have to have a very good reason to say that the most successful theory in the history of mankind is wrong about this point.
Having said that, we know that consciousness is affected by our material brain. Heck, I can whack you over the head with a hammer, cause you brain damage which will then irrevocably change the way you perceive (or not perceive) the world. I can give you some drugs that can do the same. Neuroscience has been studying the brain and consciousness and there has been ZERO evidence to suggest that the consciousness is somehow separate from the material brain. We also know that we are a products of evolution, which means the brain and our consciousness is also the product of evolution.
>I can't observe it. I can't touch it. It doesn't seem to be a physical entity as far as I can deduce.
I think I see your hang up. Part of the problem with consciousness is that a) it is an ill-defined concept, b) it is subjective to individual brains, which makes us really biased observers of it and c) people don't really want to define it. You feel that it's there, but you can't define it, and it doesn't feel like it's part of our material universe.
This is where you have to take a step back and accept the things we DO know are true, that is, our consciousness is a product of our material brains, and those brains are themselves the products of Evolution, and are made up of particles that follow well known and well tested laws of chemistry and physics. If we ever understand (or define!) consciousness, this picture is not going to change.
You say this, but show no evidence. If there is proof of this I would genuinely like to see it. I am not saying you are wrong, I just like some proof before we base everything on these assumptions.
> So you feel that it's there, but you can't define it, and it doesn't feel like it's part of our material universe.
So what is it? If it is subject to the laws of physics, then we should be able to measure it, no? Hell you cant even observe (a) consciousness. Does it have mass? Does it have energy? We can't even answer that, which is reason enough for me to question whether the laws of physics apply.
> This is where you have to take a step back and accept the things we DO know, that is, our consciousness is a product of our material brains,
Again, show me some solid proof of this. Again, I am not saying they are not related, I am pretty sure they are. But why consciousness a product of the brain? Why don't you believe they are two separate entities that interact in a two way manner?
When I choose to move my arm, my conciseness decides that, it somehow interacts with my brain, which starts firing neurons in the physical world. The consciousness becomes before the physical in that case.
You have this backwards, your arm moves and then your "consciousness" decides to perform the action after the fact, as demonstrated in the Libet experiment among others.
>Libet finds that conscious volition is exercised in the form of 'the power of veto' (sometimes called "free won't"[9][10]); the idea that conscious acquiescence is required to allow the unconscious buildup of the readiness potential to be actualized as a movement.
So he never denied conscious volition, he described it differently. Yet people claim the experiments denied conscious volition.
What do you mean, science doesn't have an answer for that either???
Then you have to explain exactly how physical particles interact with the supernatural consciousness, and for that you pretty much have to invent some new exotic physics.
>Why don't you believe they are two separate entities that interact in a two way manner?
Several reasons: 1) The theories underlying our understanding of fundamental particles and forces, have been empirically tested for decades to extremely high precision. We know they are correct in the domain of our daily experience.
2) There is no evidence that something outside the domain of applicability of our physics takes places in the brain.
3) Everything we've learned about the brain and consciousness thus far is consistent with our material understanding of the world.
So there is no reason to invent new physics to account for consciousness. If there is some evidence that shows our current physics don't work, we'll talk then, until that time, we don't need to.
In terms of specific evidence, I would point you to the Wikipedia article on Neuroscience and Free Will [1], which has a good overview of the field.
>When I choose to move my arm, my conciseness decides that, it somehow interacts with my brain, which starts firing neurons in the physical world. The consciousness becomes before the physical in that case.
That's patently not true. We know for a fact that is not the right chain of events. Neuroscience has known that for a while. In fact, your arm moves, and your mind becomes aware of it after the fact.
Sam Harris, in several of his talks gave a thought experiment in which he asked the audience to close their eyes and think of three cities, any three cities (you can try it yourself, it's pretty wild if you try to be objective). As you close your eyes, what you'll find is that three cities pop into your mind, it may be Paris, London and New York, or it may be something else. So then you ask yourself, why those particular three, and not another three? You may give yourself a reason such as "I just came from New York, so it was on my mind", but then, why that reason, and not another reason, and why not another city with its own good reason (e.g. "Istanbul, because you read a Wikipedia article about it last week).
What this shows you is that things just happen in your brain. Your unconscious brain processed the instructions in a deterministic fashion (following all laws of physics, mind you) and spat out a result into your conscious part, which itself is a product of natural processes. That you had some conscious input into this is an illusion, a very powerful illusion but an illusion nonetheless. It starts with neurons and ends with neurons.
"In many senses the field remains highly controversial and there is no consensus among researchers about the significance of findings, their meaning, or what conclusions may be drawn."
You seem very sure of the significance of the results however.
The fact is we are dealing with something which physics can't describe. So trying to shoehorn the model into classic physics is kind of dumb. A bit like trying to describe subatomic physics using the model where the atom was indivisible. We can't observe "a consciousness". How can you apply science with something you can't observe or measure? Those are fundamental parts of science.
The closest description to what modern science is doing is changing the colors of a lightbulb and then claiming they can produce electricity.
[0]: https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_R...
[0]: https://github.com/numenta/nupic/wiki/Sparse-Distributed-Rep...
I'm not too sure about that.
My gut feeling is that at least half of the information in the brain is encoded in the exact timing of the spikes. In a model that takes time into account, certain neurons function as a "coincidence detector" sensitive to certain events.
e.g. your brain deduces which direction a sound is coming from by analyzing the delay difference for the sound input from each ear to arrive to the brain. Specifically, sound-orientation detector neurons read from neurons of different lengths to each ear. You know the sound is coming from front-and-left if the coincidence-detector neuron that has a short lead to the left ear and a long lead to the right ear fires.
The receptors of sensory afferents faithfully report the timing of individual events (of photons, pinpricks of the skin, etc) with single spikes. But after a few synapses the pattern of spikes looks much more like a (noisy) rate code. The origin of the noise, whether it even is noise, how the temporal code is transformed into a rate code, and many other questions along these lines are active research topics.
All that aside, Koch is well aware that there is evidence for both rate and temporal codes. As he wrote, "spikes mean different things in different contexts."