So don't read anything about it until some one mysteriously pops up with the complete brain specification?
It is not speculation, its a hypothesis and theory which has some evidence to support it. Now they and others will go off and try to build on it, or disprove it.
I don't understand why anyone would be scornful and dismissive of this?
"So don't read anything about it until some one mysteriously pops up with the complete brain specification?"
There are between 100.000 and 250.000 publications for every popular science every year, it DOES make sense to not read those which have no scientific background nor reasoning.
First reaction was a serious, audible "Ughhh". I'm skimming the paper now but this looks a lot like "we played with some in-silico models and came up with a nifty thing"
Edit: Christ, I don't even know where to begin. Seriously.
First of all, there is no mention of the fact that microtubles don't innervate dendritic spine heads. Actin is the primary cytoskeletal support for synapses. I can think of several plausible explanations to get around this fact, but they don't offer any which immediately put me on edge for the whole paper.
Second, there is zero in-vitro experimentation. It is extremely possible that none of this happens anywhere, let alone in the brain. Granted, in-silico experiments are often used to guide future benchwork...but I would have liked to see some preliminary wet-bench tests.
Here is a gem from the paper:
MTs appear to have intrinsic electro-mechanical vibrations, e.g. coherent oscillations in the low megahertz range. [...] Signal propagation will be influenced by, and depend on MT lattice vibrations and related effects.
In LTP, high frequency inputs (e.g. 50 to 100 Hz) are required for prolonged post-synaptic response. Kumar et al [58] showed that memory formation in dendrites depends on synchronized inputs, with an optimal frequency near 50 Hz. Density and patterns of CaMKII-induced tubulin phosphorylation in post-synaptic MT lattices would depend on frequency and synchrony of inputs.
Wait, what? They are correlating electro-mechanical oscilations (MT vibrations) with electro-chemical oscilations (synaptic firing)?
‘Scale-free’ implies self-similar information patterns repeating at different spatial and temporal scales (following 1/frequency power laws). Similar to ‘fractals’ and holograms, scale-free structures and processes arise commonly in nature and technology, and are inherently robust and resistant to disruption. In the brain, evidence suggests neuronal network structure, temporal dynamics, and representation of mental states are all ‘scale-free’, with self-similar patterns repeating at various temporal and spatial scales and locations [68]–[71]. Interference patterns of periodic, coherent reaction-diffusion waves in cytoplasm and larger spatial scales could account for scale-free information patterns regulating biological systems including the brain. Microtubules can generate three-dimensional reaction-diffusion patterns [70], and we suggest such patterns operate at multiple time scales to regulate biological systems.
Translation: There are fractals in the world and we see the brain structured in certain ways, so those patterns must apply to smaller things, right? We showed some dubious computer modeling of microtubules vibrating and a kinase phosphorylating. Therefore, the vibrations are encoding brain information. QED.
There's more, but I need to get to work. Let me just put it this way: there is a very good reason this paper is not in Nature Neuroscience.
On the contrary, this is a excellent example of the benefits of open publishing. A very dubious paper is hyped in the press and the actually published work is available to all to be read and critiqued as thoroughly as it deserves. This, in my opinion, is completely independent from issues with the benefits and problems of peer review.
Thanks to the fact it is open and published under PLoS's "limited warranty" everybody can read the actual paper and are encouraged to judge it. And this is good, because papers are voices in the discussion not an indisputable statements of truth.
Nature and Science pursuit for perfection is not only futile (Schön) but also slowly changes them into scientific tabloids.
Hameroff, the author, also subscribed to the quantum brain hypothesis, along with Roger Penrose; an idea which was widely dismissed as wildly implausible, if I recall correctly. The topic itself is fascinating though.
It was dismissed as implausible at the time due to the assertion that there was no evidence for biological processes being anything other than classical. Now there has been found a wide range of quantum biological effects, from the action of chlorophyll to the mechanism of our sense of smell, so it seems a lot less implausible than it used to.
I think it is still implausible because of the vast difference in scale between quantums and neurons, several orders of magnitude. Quantum effects don't manifest themselves on a macro-scale. I don't know precisely how quantum effects help our sense of smell or with photosynthesis as has been claimed, but I reckon it has to do with localized effects. The idea that quantum effects across the brain work in concert to create a single, global consciousness is quite a bit more far fetched, if not preposterous. But if you have a particular reference saying it's considered more plausible nowadays I'd love to hear about it.
It is still widely dismissed. And while coherence seems to be relevant for a particular stage of energy conversion in photosynthesis and also in allowing sensitivity to magnetic fields, the mechanisms for leveraging these are incidental. They are used passively to achieve an effect and not actively to perform computations as would be required for Penrose's hypotheses.
To claim the brain leverages quantum effects at biological scales is going far but still plausible. But to say that quantum computations are going on in the brain and are expressed at the level of thinking we acheive (evinced by claiming that we are not Turing machines), that is something that would require a lot of data to support (something that this theory sorely lacks). Much of what we know about quantum mechanics and neurobiology would have to be redressed. Indeed if such were true there would be indirect evidence - I expect we would find quantum mechanics, heck ordinary probability theory, more intuitive for example .
Far more interesting are the epigenetic like effects that occur in memory formation.
There are independent arguments for that position, namely that it's quite likely that the brain does not everywhere operate digitally, with well-defined discrete states. And even if it did in a trivial sense because the whole of physics operated that way it wouldn't really help with describing how the brain works (wrong level of abstraction).
That's a load of hogwash. They found that some molecules match and the press is going all "brain code cracked". The authors, of course, provoked all this by linkbaiting the article (talk about modesty; also, WTF PLoS?). Nobody believes these things but these people. We have optogenetic tools to probe memory functions much more efficiently and people do that already. This came up a some time ago btw: http://news.ycombinator.com/item?id=3688953
I think there may be something to this. I write pattern/word generation software for use in password cracking and some of the most common English consonant vowel patterns are six characters long. For example, the CV pattern cvccvc matches these proper words and slang words (batman, defcon, summer, winter, bigboy, number, fatdad, hotmom, badguy, soccer, etc). This is just one example of a popular six character pattern, there are more.
The point is segmenting things by six. No need to think of the 'things' in terms of bits or bytes (of which I'm very familiar). In my example, it is popular English word patterns. In the article, it's bits in memory. Both of which are 'things' of six.
Information is defined in terms of bits, not bytes. You can define a byte to be any number of bits, https://en.wikipedia.org/wiki/Byte#History But the amount of information is determined by the number of bits, not the number of bytes.
No. That's like saying that an "hour" is extravagantly long, because we could use 30-minute hours instead. We certainly could use 30-minute hours, but it wouldn't change anything. You're just playing games with the units.
Regardless of the speculation about the number of bits, what basis do they have for the idea that memory is digital & discrete? I thought analog would be more plausible.
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[ 2.8 ms ] story [ 42.8 ms ] threadIt is not speculation, its a hypothesis and theory which has some evidence to support it. Now they and others will go off and try to build on it, or disprove it.
I don't understand why anyone would be scornful and dismissive of this?
Calling the molecule's arms is the purest and most unwarranted speculation.
There are between 100.000 and 250.000 publications for every popular science every year, it DOES make sense to not read those which have no scientific background nor reasoning.
The original article seems to be http://www.newswise.com/articles/scientists-claim-brain-memo...
First reaction was a serious, audible "Ughhh". I'm skimming the paper now but this looks a lot like "we played with some in-silico models and came up with a nifty thing"
Edit: Christ, I don't even know where to begin. Seriously.
First of all, there is no mention of the fact that microtubles don't innervate dendritic spine heads. Actin is the primary cytoskeletal support for synapses. I can think of several plausible explanations to get around this fact, but they don't offer any which immediately put me on edge for the whole paper.
Second, there is zero in-vitro experimentation. It is extremely possible that none of this happens anywhere, let alone in the brain. Granted, in-silico experiments are often used to guide future benchwork...but I would have liked to see some preliminary wet-bench tests.
Here is a gem from the paper:
MTs appear to have intrinsic electro-mechanical vibrations, e.g. coherent oscillations in the low megahertz range. [...] Signal propagation will be influenced by, and depend on MT lattice vibrations and related effects.
In LTP, high frequency inputs (e.g. 50 to 100 Hz) are required for prolonged post-synaptic response. Kumar et al [58] showed that memory formation in dendrites depends on synchronized inputs, with an optimal frequency near 50 Hz. Density and patterns of CaMKII-induced tubulin phosphorylation in post-synaptic MT lattices would depend on frequency and synchrony of inputs.
Wait, what? They are correlating electro-mechanical oscilations (MT vibrations) with electro-chemical oscilations (synaptic firing)?
‘Scale-free’ implies self-similar information patterns repeating at different spatial and temporal scales (following 1/frequency power laws). Similar to ‘fractals’ and holograms, scale-free structures and processes arise commonly in nature and technology, and are inherently robust and resistant to disruption. In the brain, evidence suggests neuronal network structure, temporal dynamics, and representation of mental states are all ‘scale-free’, with self-similar patterns repeating at various temporal and spatial scales and locations [68]–[71]. Interference patterns of periodic, coherent reaction-diffusion waves in cytoplasm and larger spatial scales could account for scale-free information patterns regulating biological systems including the brain. Microtubules can generate three-dimensional reaction-diffusion patterns [70], and we suggest such patterns operate at multiple time scales to regulate biological systems.
Translation: There are fractals in the world and we see the brain structured in certain ways, so those patterns must apply to smaller things, right? We showed some dubious computer modeling of microtubules vibrating and a kinase phosphorylating. Therefore, the vibrations are encoding brain information. QED.
There's more, but I need to get to work. Let me just put it this way: there is a very good reason this paper is not in Nature Neuroscience.
Nature and Science pursuit for perfection is not only futile (Schön) but also slowly changes them into scientific tabloids.
We certainly used to think so, not so much any more. http://physicsworld.com/cws/article/news/2003/sep/03/entangl...
To claim the brain leverages quantum effects at biological scales is going far but still plausible. But to say that quantum computations are going on in the brain and are expressed at the level of thinking we acheive (evinced by claiming that we are not Turing machines), that is something that would require a lot of data to support (something that this theory sorely lacks). Much of what we know about quantum mechanics and neurobiology would have to be redressed. Indeed if such were true there would be indirect evidence - I expect we would find quantum mechanics, heck ordinary probability theory, more intuitive for example .
Far more interesting are the epigenetic like effects that occur in memory formation.
There are independent arguments for that position, namely that it's quite likely that the brain does not everywhere operate digitally, with well-defined discrete states. And even if it did in a trivial sense because the whole of physics operated that way it wouldn't really help with describing how the brain works (wrong level of abstraction).
But i don't think it applies to words (other languages are very different)
If you want a (still speculatory) but rigorous take on this: http://www.med.nyu.edu/buzsakilab/content/PDFs/Buzsaki2010Ne...
Computers nowadays standardized on eight bit bytes, synonymous with octet, but the definition of a byte is actually hardware-dependent.
Our pattern matching engine is extremely prone to false positives.
I'm reminded that "nature is lazy" and always goes for the easiest and quickest route for efficiency.