Energy and brain activity

[neuro]

Brain activity poses an interesting two-level question about the energy needed to elaborate information:
1. information theory and Maxwell daimon have taught us that information content (decrease in randomness, negentropy) has an energetic cost.
2. the biochemical and electrical work of nerve cells, involved in information processing, must have an energetic cost which exceeds the mere informational work.

Actually, both aspects are relevant, as intense information processing requires a larger bandwidth (which corresponds to modulating spike emission rate by neurons over a larger range of frequencies, say 10-200 Hz); generating high spike rates, in turn, is metabolically demanding both in terms of electrical activity and in terms of transmitter release processes.

However, brain circuits generally are constantly active, even during sleep - contrary to the naive idea that sleep is necessary for neurons to rest.
Functional NMR studies indicate that blood flow to a particular area may increase to about +80% when such area is intensely activated, and oxygen extraction from blood (the BOLD NMR signal) may simultaneously increase by few percent. Thus, the energetic requirement appears to increase up to about twofold when a cerebral area is intensely activated, but not much more than that. (I am not an expert in NMR. These figures might be inaccurate due to my limited knowledge of literature, by I am quite confident that the order of magnitude is correct)

This suggests that energetic needs of neuronal activity should not be the limiting step (requiring a doubling of oxygen and glucose supply to a cerebral area is not so much demanding for the circulatory system).
On the other hand, neurons (and synapses) display fatigue, adaptation and self-limitation phenomena, which are not related to lack of oxygen/glucose supply, but to ionic unbalances (following intense, continuous activation of ion currents to sustain electrical activity), vesicle depletion at the nerve terminals, inactivation of receptors, inhibitory feed-back circuits, etc.

In conclusion, cognitive activity, thought and consciousness are demanding tasks for neurons, but not because there are problems in adequately supplying them with oxygen and glucose; rather, because the efficiency with which biochemical and functional changes involved in activity are recovered from is limited.

I should appreciate your comments and objections

[owleye]

....
This suggests that energetic needs of neuronal activity should not be the limiting step (requiring a doubling of oxygen and glucose supply to a cerebral area is not so much demanding for the circulatory system).
On the other hand, neurons (and synapses) display fatigue, adaptation and self-limitation phenomena, which are not related to lack of oxygen/glucose supply, but to ionic unbalances (following intense, continuous activation of ion currents to sustain electrical activity), vesicle depletion at the nerve terminals, inactivation of receptors, inhibitory feed-back circuits, etc.

In conclusion, cognitive activity, thought and consciousness are demanding tasks for neurons, but not because there are problems in adequately supplying them with oxygen and glucose; rather, because the efficiency with which biochemical and functional changes involved in activity are recovered from is limited.

I should appreciate your comments and objections

Interesting. If I'm to appreciate this, I think I need to know how to relate it to something anyone would be familiar with. Though the energy costs of information are not the limiting factor, in a ball park sense how many kilowatts of power do you think would be devoted to such information processing? I've heard that the efficiency of ATP and the Krep's (?) cycle is very high and so we might assume that overall, information processing would be highly efficient, despite what it has to work with.

Also, I'm not getting a clear picture of what you have in mind by "because the efficiency with which biochemical and functional changes involved in activity are recovered from is limited." In the context of information processing, this would come under the category of design constraints, so that part of it is clear enough (though in some sense it yet remains part of the actual overall energy cost of information). What is missing in my mind is the recovery process itself. Is recovery of the sort that is local to each of the cells or group of cells forming a functional entity or is it coordinated with other such entities, in the sense of a tag-team or even, conceivably, as a well-oiled army able to fill battle worn entities with recovered ones? (I'm not suggesting centralized control, though there may be some local hierarchies required for this to work -- maybe it's more like how ants in an ant colony work.)

James

[neuro]

Though the energy costs of information are not the limiting factor, in a ball park sense how many kilowatts of power do you think would be devoted to such information processing?

I think there are three distinct aspects in the relationship among thermodynamic cost of information, energy requirement for neuronal activity and the rate of biochemical re-equilibration in neurons during intense activity.
Depending on local conditions (phosphate balance, pH, etc) a molecule of ATP can deliver some 7-13 kT of work (k=Boltzmann's constant, T= absolute temperature=300°K at 37°C).
I should need some help by somebody who knows better about thermodynamics and information theory, but if I am not too wrong 10 kT=3,000 k should correspond to some 3000/log(2)=4,328 bits of information.
If you assume that a neuronal action potential may carry a bit of information (this is taking quite a bit [!?] of liberty, but I am talking about orders of magnitude), you should consider that generating an action potential costs to a neuron (this is a very rough computation, and may be again wrong by some orders of magnitude – see for example this paper) some 10⁶ molecules of ATP
So, the problem is not the cost of “information” but rather that (some 10¹⁰ times higher) of the biochemical machinery to represent and elaborate it. Furthermore, the “marginal” cost (to borrow a concept from economics) of information processing is not very high, as cerebral neurons do not stop firing at “rest” and energy consumption by a cerebral circuit does not rise to more than twofold its “resting” value during intense activity (much less for the whole brain).
Overall, considering that total body basal metabolic rate is in the order of 1500 kcal/day, the organism needs some 6.3 MJ/day (something more than 70 W, if I computed it correctly), of which you can estimate that some 15-20 W are used by nervous system activity. Intense "information processing" may raise this overall need of some percent points (i.e. possiblly up to, say, 3-5 W) [see. for example, ref: "Compared to the mentally alert young man with an O2 consumption of 3.5 mL per 100 g per minute, the mentally confused states associated with diabetic acidosis, insulin hypoglycemia, and some forms of cerebral arteriosclerosis might typically show O2 consumptions rates down to 2.8 mL per 100 g per minute"]

Also, I'm not getting a clear picture of what you have in mind by "because the efficiency with which biochemical and functional changes involved in activity are recovered from is limited." In the context of information processing, this would come under the category of design constraints, so that part of it is clear enough (though in some sense it yet remains part of the actual overall energy cost of information). What is missing in my mind is the recovery process itself.

Whenever a neuron generates an action potential, some millions sodium ions enter from the extracellular liquid into the neuron; this has to be balanced by active extrusion (powered by ATP hydrolysis); apart from the energetic aspect, this requires time, so that during intense activity the capacity of the neuron to restore its electrochemical resting condition may be outpaced by ion fluxes involved in electrical activity, and the neuron may slowly drift away from its ideal biochemical condition. Similarly, transmitting a signal across a synapse implies the release of neurotransmitter from some (few to 100, depending on the synapse) synaptic vesicles; these have to be reformed and refilled with re-uptaken or re-synthesized transmitter; again, apart from the energy aspect, this requires time. The synapse generally has a good store of preformed vesicles, continuously reformed and refilled, but intense activity may gradually deplete such stores. This is reminiscent of how the muscle cell, during intense activity, gradually depletes its store of high energy compounds (phosphocreatine), glucose (stored as glycogen) and oxygen (stored in myoglobin), until it becomes strictly dependent on blood supply of oxygen and glucose, and must therefore limit its activity.
Thus, I think you are correct in assuming that there must be a tendency to a general oscillation, waxing and waning cycles, activity and recovery in the activity of neuronal circuits. But this is not because of problems in energy supply; it rather derives from the fact that intense activity may outpace the rate at which neurons preserve and restore their complex biochemical state.

Is recovery of the sort that is local to each of the cells or group of cells forming a functional entity or is it coordinated with other such entities, in the sense of a tag-team or even, conceivably, as a well-oiled army able to fill battle worn entities with recovered ones? (I'm not suggesting centralized control, though there may be some local hierarchies required for this to work -- maybe it's more like how ants in an ant colony work.)

I cannot think of any functional turnover process in the overall activity of the nervous system, in the sense of the duties of worn-out circuits being performed by other circuits. As said above, however, each cell has a series of quite relevant reserve and backup resources, which permit it to perform at higher rates than its metabolic efficiency would be able to sustain; this, however, can only be done for a limited period (as long as reserve mechanisms are not exhausted).

[owleye]

,,,
So, the problem is not the cost of “information” but rather that (some 10¹⁰ times higher) of the biochemical machinery to represent and elaborate it. Furthermore, the “marginal” cost (to borrow a concept from economics) of information processing is not very high, as cerebral neurons do not stop firing at “rest” and energy consumption by a cerebral circuit does not rise to more than twofold its “resting” value during intense activity (much less for the whole brain).

Based on your previous points, I'd been thinking (also borrowing a concept from economics) that, from the standpoint of energy, information shouldn't be thought of as a scarce resource in and of itself, since much like an electrical outlet, there exists a stable flow from which to draw (notwithstanding exceptions). It is the maintenance of the infrastructure that is the primary drain, and even here, there is sufficient energy from the wall socket to handle it. (Obviously there are costs, and such, it is to some degree a scarce resource, and as such it will have to be paid for. I'm merely thinking of it from the standpoint of the way the delivery system to the brain is designed in the way you've described it.)

... (skipped over interesting set of calculations that estimate energy usage associated with information processing, which I find impressive as well as informative)

Whenever a neuron generates an action potential, some millions sodium ions enter from the extracellular liquid into the neuron; this has to be balanced by active extrusion (powered by ATP hydrolysis); apart from the energetic aspect, this requires time, so that during intense activity the capacity of the neuron to restore its electrochemical resting condition may be outpaced by ion fluxes involved in electrical activity, and the neuron may slowly drift away from its ideal biochemical condition. Similarly, transmitting a signal across a synapse implies the release of neurotransmitter from some (few to 100, depending on the synapse) synaptic vesicles; these have to be reformed and refilled with re-uptaken or re-synthesized transmitter; again, apart from the energy aspect, this requires time. The synapse generally has a good store of preformed vesicles, continuously reformed and refilled, but intense activity may gradually deplete such stores. This is reminiscent of how the muscle cell, during intense activity, gradually depletes its store of high energy compounds (phosphocreatine), glucose (stored as glycogen) and oxygen (stored in myoglobin), until it becomes strictly dependent on blood supply of oxygen and glucose, and must therefore limit its activity.

Yes, I assumed something like this not just from what you've written but generally as a feature of physiology, if not psychology, I'd been exposed to over a lifetime of interest in them. (Note, I'm over 70.)

I cannot think of any functional turnover process in the overall activity of the nervous system, in the sense of the duties of worn-out circuits being performed by other circuits. As said above, however, each cell has a series of quite relevant reserve and backup resources, which permit it to perform at higher rates than its metabolic efficiency would be able to sustain; this, however, can only be done for a limited period (as long as reserve mechanisms are not exhausted).

I think what I had in mind has to do with the ability of the brain to improve performance by way of conditioning the means of achieving it -- making it more efficient, less wasteful, and so forth. Military terms are a handy metaphor for describing the results of this achievement, and even creeps into the biological vocabulary in the form of regarding certain ants as army ants. I was just wondering whether the wax/wane cycle can be subjected to this kind of conditioning and how best to characterize the results, if it could do so. In the case of the immune system, for example, one uses the term 'recruit' to indicate that on detection of an antigen, antibodies are produced in quantity. I've also heard the term used within performance physiology to indicate how blood vessels are recruited for certain activity, or that particular parts of a muscle (i.e, certain fast twitch muscle fibers can change their role so they can be used as if they were slow twitch, or something like that). There might even be a higher level control of red blood cell creation within bone marrow. I'm afraid I get carried away with all the things the brain might be able to accomplish. Obviously there has to be some good reason why we have skulls, but I may be over doing it.

James

[neuro]

So, the problem is not the cost of “information” ....

Based on your previous points, I'd been thinking (also borrowing a concept from economics) that, from the standpoint of energy, information shouldn't be thought of as a scarce resource in and of itself, since much like an electrical outlet, there exists a stable flow from which to draw (notwithstanding exceptions).

Actually, I was not talking about the cost of gathering information, but the energetic cost of making a choice in processing information: a binary classification (yes/no) has a cost in terms of physical (thermodynamic) units, Joules, calories (though it macroscopically is pretty tiny)

I think what I had in mind has to do with the ability of the brain to improve performance by way of conditioning the means of achieving it -- making it more efficient, less wasteful, and so forth. Military terms are a handy metaphor for describing the results of this achievement, and even creeps into the biological vocabulary in the form of regarding certain ants as army ants. I was just wondering whether the wax/wane cycle can be subjected to this kind of conditioning and how best to characterize the results, if it could do so. In the case of the immune system, for example, one uses the term 'recruit' to indicate that on detection of an antigen, antibodies are produced in quantity. I've also heard the term used within performance physiology to indicate how blood vessels are recruited for certain activity, or that particular parts of a muscle (i.e, certain fast twitch muscle fibers can change their role so they can be used as if they were slow twitch, or something like that). There might even be a higher level control of red blood cell creation within bone marrow.

Actually, even in the brain it has been amply shown that "exercise develops the muscle": most cerebral functions become more efficient in using them. But this is a slow process, it only occurs in the long run and requires complex remodeling of circuits.
On the other hand, similarly slow processes occur after brain injuries as well: spared regions of the cortex may take on functions that were initially performed by areas damaged by stroke, for example.

[owleye]

neuro...

Any thoughts on how idiot savants do their calculations so quickly? How about folks who have the ability to reproduce something (like an entire aerial scene of a city) from taking only one aerial pass over it. I've seen a clip of the the Vatican rendered in this way -- truly amazing. Something interesting must be going on in the brain that we ordinary souls lack. Might energy be more efficiently used in such folks or is energy just a wash, and it just a difference in the wiring?

James

[neuro]

Any thoughts on how idiot savants do their calculations so quickly? How about folks who have the ability to reproduce something (like an entire aerial scene of a city) from taking only one aerial pass over it. ... Might energy be more efficiently used in such folks or is energy just a wash, and it just a difference in the wiring?

It is difficult to say whether energy is used in a different way. I would tend to say: essentially no.
But differences in wiring certainly appear to be there.
You certainly know that most idiots savants would be medically classified within the Autistic Spectrum Disease (ASD), and non-idiot people may share such kind of abilities, but they generally are ASD (high performance) as well.
The causes of ASD are multiple, some 100 genes have been spotted up to date as sufficient or possible causes and many more may be involved. However, a common feature of autistic brains is a decrease in long-range connections and an increase in local connectivity, within the cortex. Given the importance of connections among different cortical areas for integrated consciousness and behavioral performance, this is thought to explain both the difficulties in communication and social behavior and the tendency to stereotypies and repetitions. On the other hand, in case overall cognitive performance is not compromized, local hyperconnectivity might give rise to abnormal enhancement of specific computational capabilities.

[owleye]

...On the other hand, in case overall cognitive performance is not compromized, local hyperconnectivity might give rise to abnormal enhancement of specific computational capabilities.

This is interesting. It is not uncommon that deficiencies in one area are compensated for by efficiencies in other areas. (I'm thinking here mostly of the coping strategies of the blind, but I suppose it could extend into other areas as well.)

James

[psionic11]

SYG-2000-15229-201110

I find this discussion very interesting, and have dabbled a "bit" in neuroscience enough to follow along with the technical aspects of what's being said. Much of the posts have dealt with the mechanisms and constraints of neurochemical processing. I found these points most relevant:

1. information theory and Maxwell daimon have taught us that information content (decrease in randomness, negentropy) has an energetic cost.
2. the biochemical and electrical work of nerve cells, involved in information processing, must have an energetic cost which exceeds the mere informational work.

Functional NMR studies indicate that blood flow to a particular area may increase to about +80% when such area is intensely activated

I think there are three distinct aspects in the relationship among thermodynamic cost of information, energy requirement for neuronal activity and the rate of biochemical re-equilibration in neurons during intense activity.

Intense "information processing" may raise this overall need of some percent points (i.e. possiblly up to, say, 3-5 W)

... it rather derives from the fact that intense activity may outpace the rate at which neurons preserve and restore their complex biochemical state.

Actually, even in the brain it has been amply shown that "exercise develops the muscle": most cerebral functions become more efficient in using them. But this is a slow process, it only occurs in the long run and requires complex remodeling of circuits.

On the other hand, in case overall cognitive performance is not compromized, local hyperconnectivity might give rise to abnormal enhancement of specific computational capabilities.

So we've established that there is a base operating minimum, an energy "noise floor", or as owleye put it, the electrical wall outlet that always provides the energy needed. We know about the time constraints and computational limitations of local synaptic activity. Finally, performance efficiency of specific cerebral functions increases over time, much as exercise develops muscle or in musician's parlance, "practice makes perfect." This is why performing artists rehearse their parts over and over, why students study with flash cards or other mnemonic devices, and how young children learn the indoctrinations of the culture they're raised in, or more specifically, how they learn language by being immersed in it and repeating key phrases over and over and thus gradually build up their phrase repertoire and grasp of grammar until fluency is achieved.

What I'd like to ask about is what is known regarding increasing the efficiency of specific cerebral functions, or perhaps in general performance raising. Let me give a personal example as a launching point for discussion --

For the past couple of years, I've turned my musical attention to learning piano sonatas. Many of us know about Beethoven's Moonlight sonata, and for me the first movement only gradually coalesced into a becoming a single playable performance after several years of dabbling with it (I'm mostly a guitarist/bassist and trombonist with a decent foundation in musical theory).

More to the point -- having made a conscious decision to dedicate myself to learning the Moonlight Sonata's difficult 3rd Movement, over the long term I've noticed a trend in this particular set of cerebral functions. This sonata has hit a plateau, but each new piano piece is becoming exponentially easier to memorize and perform up to speed, taking only weeks instead of months to learn. So, as noted, "exercise develops the muscle." Also, within a particular practice session on a day off from work, after breakfast, much caffeine, and a one to two hour groove of "being in the zone", my technical performance reaches a high, and my ability to transcend the technical aspects to reach into the wider levels of expression and improvisation increases. This point is usually not reached until food, caffeine, and a couple continuous hours of practice time have all converged. This point is also a quite pleasurable and sustained state of reward, an almost addictive pleasure where the mundane falls away and the thoughts seem more alive and fluid compared to normal.

So here are the questions: Are there functional NMR studies showing increased output or efficiency in specific cerebral processes that involve repeated rehearsal of those routines? Are there other ways to measure not so much the thermodynamic aspects but more of the informational processing aspects? Can informational efficiency even be objectively measured? Finally, what role does caffeine and perhaps even the dopamine reward systems have to do with the energizing of these specific cerebral functions and the consequent increase in efficiency?

In other words, are there indicators pointing to a more neurochemical solution to increasing cognitive potential (smart drugs, nutritional supplements, neurohormonal boosters)... or is the subject of increased mental performance more in the domains of behavioral psychology, learning institions (curricula or internship), knowledge experts, or curious self-help techniques (Anthony Robbins, Stephen Covey)?

Anyone can study or repeat routine tasks over and over. How can we step up efficiency?

[neuro]

What I'd like to ask about is what is known regarding increasing the efficiency of specific cerebral functions, or perhaps in general performance raising. Let me give a personal example as a launching point for discussion -- ...
having made a conscious decision to dedicate myself to learning the Moonlight Sonata's difficult 3rd Movement, over the long term I've noticed a trend in this particular set of cerebral functions. This sonata has hit a plateau, but each new piano piece is becoming exponentially easier to memorize and perform up to speed, taking only weeks instead of months to learn. So, as noted, "exercise develops the muscle."

Learning a psychomotor task involves a quite fascinating interaction and synergy among neural systems. Whenever you perform a complex motor task, premotor areas in the frontal cortex elaborate the complex series of orders to be given to the muscles and the primary motor cortex (frontal) executes them. Meanwhile, the inferior olive (a brainstem nucleus) keeps comparing motor "orders" with the resultant position of muscles and joints; if it finds some inconsistencies, it sends this information to the cerebellum which corrects the movement. This circuit is much more efficient and rapid than the cortex (if the cerebellum is damaged movements are less precise and controlled). The cerebellum, which contains more than half of the neurons in the whole nervous system, also receives information by all sensory inputs and has a very plastic connectivity, so that it associates the motor orders it is sending (obeying the inf.olive) to the current sensory status; when this procedure is repeated, for a specific motor performance, the cerebellum becomes capable of executing it without cortical control; by the same token it is involved in classical conditioning, and in automatic tasks required by cognitive activity and language (taking care of grammar, of the order of the words in the sentence, of the tenses of verbs, of desinences and so on).
The extraordinary result of this control + servo-control system is that on the one hand, once learned, complex motor tasks are performed more precisely, rapidly and efficiently (because there is no need for the cortex to keep computing what to do and, slow[!] as it is, intefere with the movements); on the other hand, the cortex can turn to other aspects: much like a general who, after giving an order, does not have to care about how the order is executed, the cortex (our conscious concern) can turn to something else. If what we are performing has an emotional and/or esthetic component, then we can care about those aspects rather than performance.
Another wonderful fallback of this process is that similar motor tasks profit quite a lot of the established "tuning" of the control + servo-control system (cortex and cerebellum), so that learning similar tasks becomes much easier and faster.

Also, within a particular practice session on a day off from work, after breakfast, much caffeine, and a one to two hour groove of "being in the zone", my technical performance reaches a high, and my ability to transcend the technical aspects to reach into the wider levels of expression and improvisation increases. This point is usually not reached until food, caffeine, and a couple continuous hours of practice time have all converged. This point is also a quite pleasurable and sustained state of reward, an almost addictive pleasure where the mundane falls away and the thoughts seem more alive and fluid compared to normal.

You forget two aspects: cortisone being at its peak some 2-3 hors after waking up in the morning, and a kind of virtuous cycle among the esthetic pleasure of music, endorphine levels during pleasurable activity, the pleasure of performing at your best, and the possibility of expressing emotional states and feelings through this activity...

So here are the questions: Are there functional NMR studies showing increased output or efficiency in specific cerebral processes that involve repeated rehearsal of those routines?

I am pretty sure there must be NMR studies on this, but I am not a cerebral imaging expert and would only suggest you to search Pubmed on the topic, if you have access (I may do it for you if you don't).
On the other hand, you should be aware that functional studies cannot measure the "efficiency" of the process: presumably, you would have more oxygen consuption during learning than when your proficiency has increased; if you think again of the military similitude, when the army has become more organized and efficient in performing a task, the latter will not fatigue the soldiers more than it used to when they were learning.

Are there other ways to measure not so much the thermodynamic aspects but more of the informational processing aspects? Can informational efficiency even be objectively measured?

This is an interesting question. To my knowledge, at the moment the answer is NO to both questions. Or, better, you can measure informational efficiency by evaluating performance (either cognitive or psychomotor), but this is quite ovious, ain't it.

Finally, what role does caffeine and perhaps even the dopamine reward systems have to do with the energizing of these specific cerebral functions and the consequent increase in efficiency?

I believe they have a paramount role in this. Not only in terms of activation of reward system, but in the overall control of the process. The integration of different movements (and cognitive tasks) into a fluid and harmonic sequence is the main responsibility of basal ganglia, another particularly complex and fascinating servo-mechanism for the cortex; the whole activity of the basal ganglia is under accurate control by dopamine, released from terminals of neurons originating from the substantia nigra; the latter is nearby the other dopaminergic systems involved in reward (in the mesencephalon, which therefore constitutes a central relay in emotional and motivational control circuitry). Note that degeneration of the substantia nigra is the main problem in Parkinson's disease and is responsible for all the motor, affective and psychological disturbances in that disease.

In other words, are there indicators pointing to a more neurochemical solution to increasing cognitive potential (smart drugs, nutritional supplements, neurohormonal boosters)... or is the subject of increased mental performance more in the domains of behavioral psychology, learning institions (curricula or internship), knowledge experts, or curious self-help techniques (Anthony Robbins, Stephen Covey)?
Anyone can study or repeat routine tasks over and over. How can we step up efficiency?

Well, I am rather skeptic on all this story. Whereas using the built-in mechanisms for learning can certainly be profitable, and learning how to use them at best can be even more profitable, I do not believe in any neurochemical approaches: in the face of defects and disfunctions, the neurochemical approach (diet, drugs, whatever) may help compensating the defect. On the contrary, in a well-functioning brain, they always create more problems than they can solve. It would be like spraying some oil into a computer case hoping that everything may run more smoothly...
The system is too complex and no molecule has a single target.
I am afraid that, apart from learning to use it better, if we want our brain to WORK better we shall have to wait for evolution to improve it.
It may take quite a while, though.

[psionic11]

Thank you for the replies. Interesting -- so the cerbellum is actually involved in supposedly higher cognitive functions like grammar... I had some idea that its main purpose was the coordination of sensory and motor functions, but that it's involved in off-loading repetitive cognitive computation is surprising.

Certain species have highly developed cerbella compared to relatives within their clade. There's a type of benthic fish that uses electric fields as part of its sensory system, and it has a highly developed cerebellum to deal with this. I'm guessing that primates have a relatively very developed cerebellum, being tree-dwellers (balance and hand-eye coordination). Do humans have a further developed cerebellum compared to our closer relatives?

On the neurohormones -- thanks also for the bit on cortisone. I guess I shouldn't find it too surprising that cortico levels will rise and fall throughout the day, as melatonin and serotonin also have their cycles. I will have to do some Wiki research on cortisone. I don't suppose a layperson or college student would have access to PubMed...

Finally, the negative answer as to whether we can objectively measure and increase the efficiency of informational processing is a bit of a letdown. Neuroimaging and other measurements thus far seem only to provide quantities more than qualities. But we are on the cusp of understanding functional systems and thus a more qualitative understanding, aren't we? You mentioned in another thread that we have two systems that alternate with each other -- one that monitors wandering thoughts and attention, which then subsides as the cortex executes specific activities. Isn't it the anterior cingulate cortex (the "oops" center) that also provides feedback, alerting us when something unexpected happens, like a mistake? I'm guessing that this is part of the network that is active during the attention and planning stage of the two systems that alternate...

[neuro]

Certain species have highly developed cerbella compared to relatives within their clade. There's a type of benthic fish that uses electric fields as part of its sensory system, and it has a highly developed cerebellum to deal with this. I'm guessing that primates have a relatively very developed cerebellum, being tree-dwellers (balance and hand-eye coordination). Do humans have a further developed cerebellum compared to our closer relatives?

I am not an expert in comparative anatomy and physiology. So I do not know whether our cerebellum is more developed than that of other animals to the same extent to which cerebral cortex is more developed. Still, The cerebellum is connected with most of the cortex, and plays its support role towards all areas, thus I would suspect that rather than a massive overall increase, the relative weight of the cerebellar areas involved in baseline motor tasks (notice that standing up loads quite a lot of work on the cerebellum), fine adjustment of movements (hand, tongue, tail!) and cognitive tasks should be quite different.

On the neurohormones -- thanks also for the bit on cortisone. I guess I shouldn't find it too surprising that cortico levels will rise and fall throughout the day, as melatonin and serotonin also have their cycles.

It does, and our feeling more or less "energetic" during the day essentially parallels its levels. Just a detail, I said cortisone to be more direct, but to be appropriate the most important endogenous hormones of the adrenal cortex are cortisol and corticosterone (which have the same effects).

I will have to do some Wiki research on cortisone. I don't suppose a layperson or college student would have access to PubMed...

Actually, PubMed is free access: the problem is only a minority of the published articles can be accessed in "full text" from a private connection. College students may have full access through institutional connections.

we have two systems that alternate with each other -- one that monitors wandering thoughts and attention, which then subsides as the cortex executes specific activities. Isn't it the anterior cingulate cortex (the "oops" center) that also provides feedback, alerting us when something unexpected happens, like a mistake? I'm guessing that this is part of the network that is active during the attention and planning stage of the two systems that alternate...

The anterior cingulate and the surrounding areas (ventromedial prefrontal cortex) certainly are the key regions for orienting and triggering the execution of cognitive and motor tasks. And surely they are considered as part of the "resting state network": actually, in a sense they may play a role of "control" over the resting state network itself...

[owleye]

...
For the past couple of years, I've turned my musical attention to learning piano sonatas. Many of us know about Beethoven's Moonlight sonata, and for me the first movement only gradually coalesced into a becoming a single playable performance after several years of dabbling with it (I'm mostly a guitarist/bassist and trombonist with a decent foundation in musical theory).

More to the point -- having made a conscious decision to dedicate myself to learning the Moonlight Sonata's difficult 3rd Movement, over the long term I've noticed a trend in this particular set of cerebral functions. This sonata has hit a plateau, but each new piano piece is becoming exponentially easier to memorize and perform up to speed, taking only weeks instead of months to learn. So, as noted, "exercise develops the muscle." Also, within a particular practice session on a day off from work, after breakfast, much caffeine, and a one to two hour groove of "being in the zone", my technical performance reaches a high, and my ability to transcend the technical aspects to reach into the wider levels of expression and improvisation increases. This point is usually not reached until food, caffeine, and a couple continuous hours of practice time have all converged. This point is also a quite pleasurable and sustained state of reward, an almost addictive pleasure where the mundane falls away and the thoughts seem more alive and fluid compared to normal.
...

I as well am interested in this area. Though I'm not a musician and never will be, I, too, am making an attempt to learn difficult pieces on the piano. To steal a line from someone I know in a completely different context, translating: "a non-musician, like myself, would practice a piece until they get it right, whereas a musician would practice a piece until they don't get it wrong." I confess not even ever achieving the former, though on occasion I come close. Even so, I do appreciate the 'zone' you speak of. It is something I don't experience often (and certainly not to the level you appear to be capable of), but there is a bit of magic in it, I think.

Anyway, of interest here is that I assume you begin by playing against sheet music and at some point disengage this and begin to practice without it until you've mastered it, possibly here and there checking with the sheet to make sure you've played it right, or maybe not, and practice until it sounds like someone who you believe plays it the way you'd like to. (Note that, for me, I never really get past the sheet music stage, it being very difficult for me to memorize pieces, or that I don't know the tricks for this, or that I don't practice enough, etc.) In any case, in consideration that reading sheet music involves language translation to action, it seems not all the activity is related to conditioning the fingers to play by themselves, so to speak. Some cerebral energy would require devoting oneself to reading the music. Indeed, this may require considerable concentration. What I usually do is get to a place where I can read the bass clef and play the treble clef by ear or to a lesser extent, merely automatically. Once this occurs, improvement is a lot faster, suggesting that to achieve the highs you need to be able to have memorized it, ridding oneself of the sheet music altogether. Of course, I've also heard that memorization and its recall involve imagining the sheet music in front of you and playing off of it -- but this doesn't sound right.

James

[psionic11]

Glad to hear someone interested in learning music, even better is merging discussion about brain activity and learning...

It seems to me that there are various stages or functional areas involved in learning to play a song free of sheet music and entirely concentrating on the emotional performance. I guess a parallel could be drawn to an actor getting his script handed to him to the point of delivering that perfect take on camera. It also draws from the same domains as learning language -- understanding elements and how they work together, as in meaning, both relational and independently, and in the rules, like grammar or music theory or acting styles. Then there is the area of sheer memorization... and this also involves more than one level. We don't just memorize words, but also phrases, tenses and conjugations, idioms, delivery or intonation, context, etc.

Anyhow, so as not to hijack the thread so much, let's return a bit to the corresponding activities in the brain. What little I know is that the cortex processes higher cognitive functions, the hypothalamus is involved in memory formation, that symbolism and language processing goes through Brodmann's and Wernicke's areas, and as mentioned earlier, the cerebellum offloads repetitive tasks given to it from the cortex. Unlike computer memory, less is not more. Meaning that the more a particular stimulus is presented to the brain, the more likely it is to retain and have immediate access to it in the future. Repetition.

But a similar principle applies -- you don't want to just stimulate one particular functional area (blind rote memorization of "facts" or musical motions). You want to engage several areas simultaneously. There are, for example, mnemonic techniques that go back to the Greek and Roman orators of old. Techniques where you associate pictures and colors and other outlandish ideas or tags to one particular idea. What this does is bloat the one simple, boring and hard-to-memorize concept (Leather Jacket, model 1776ac-007) with something strikingly easy to remember: At the end of a cold winter when our country was founded, James Bond skinned a deer and made a nice leather jacket to keep himself warm. See the mnemonic hints, and how you've conjured an image easily remembered in the future?)

So, in the same way, when learning new music, you pull together several levels and you progress up the stage. First, of course, you must identify those levels, and perhaps even step back and populate or fill them out with the appropriate framework -- individual note names and what scales and chords they belong to, traditional chord voicings and progressions versus ones that break the rules, allusions to other musical motifs, the use of motifs and their variations, the likely type of audience or intent for the piece, the emotions intended or their historical context, practice with a metronome, exaggerated use/misuse of the sustain pedal or soft/loud passages, imagining a particular line executed by a brass instrument or a voice instead, etc.

This may seem a lot, but like in the mnemonic example, the more you associate with a part, the more "tags" you give to the section you're trying to memorize (both mechanically with your hand memory and also with musical meaning), then the more weight and substance and life you give to it, thus making it more easily memorable.

Whew, sorry for the long-winded explanation. It takes paragraphs to deliver in writing, but only a minute when spoken.

Bringing it full circle, what I imagine happens in the various brain centers are measurable and predictable associations. Visualizing a scene activates the parts of the visual cortex processing centers, hearing internally still excites auditory nerves (well not the cochlea, but the auditory processing centers), conscious attention to measured and repeated fingering techniques eventually gets written into the cerebellum, and the whole experience gets recorded into the hypothalamus. Overall, when the nitty-gritty details start to become second-nature, the resting state awareness system can kick in, allowing a more existential or transcendent shift of experience to the performance, and once again the cortex can slightly modulate the automated delivery that the cerebellum is delivering, changing the performance to deliver a slightly louder accent here, a more staccato part here, more sustain pedal here, etc., and the more successful renditions giving a feedback loop which boosts the dopamine levels at that particular moment, causing the moment to be recorded and referenced again in the future at the right time -- all this resulting in a more overall emotional and polished performance.

And over time, as these all gel together and the working parts of the machinery get well-greases, memorization actually comes easier, not harder, as it would in a space-dependent environment like serial processing CPUs and hard disks. This is what allows us to distinguish a beginner or amateur from a professional musician -- the amount of refinement, on many levels, including technical mastery, choice or expense of instrument, the context or mood, and the very place you are witnessing the master perform (environmental clues).

This is all why I was asking if there are hints as to some ways to improve informational efficiency. It's not just a matter of more flash cards, or thicker books, or more caffeine. It's more of everything on many levels -- meaning, memorization, association, repetition, self-evaluation, refinement. Much of this is the domain of learning experts, but I imagine there must be some neuroscientists familiar enough with the academic psychological aspects to provide clues as to which functional areas relate to what and, more importantly, how they inter-relate with other areas. Knowing this, there must be then some physical things we can do to foster these interconnections to boost efficiency -- time of day, lighting conditions, nutrition and supplements, electric or magnetic stimulation, biofeedback, physical exercise and blood flow, oxygen levels, etc.

I'll stop now.

[neuro]

hi psionic11,
I like this last post, because it hits what in my opinion is the crucial point.
Memory is mostly, as you say, a trick of connecting information, so that richness and ease of retrieval are both enhanced.
If one thinks of the enormous brain plasticity in an infant (and her rate of learning) or a child, as compared to a young adult, one should suppose that memorizing be the easiest for the infant. Instead this capacity grows with age (otherwise why wouldn't we - nor wouldn't a child - recall anything that happened in the first years of life?), exactly because the network of possible connections grows and makes it easy to fix new "information", which is not fixed as raw data (as a computer would do) but in terms of procedures to reproduce it (and putting together pieces is easier than building from scratch...)

This is all why I was asking if there are hints as to some ways to improve informational efficiency. It's not just a matter of more flash cards, or thicker books, or more caffeine. It's more of everything on many levels -- meaning, memorization, association, repetition, self-evaluation, refinement.

Agree. And I think that if one is looking for a bit of creativity as well, then the question is not only "on many levels -- meaning, memorization, association, repetition, self-evaluation, refinement" but also, and maybe specially, on many modes, by switching standpoints and attitudes, and gathering stimuli from each topic and perspective.
(though maybe this is only my own trick, which I turn to, in search of creativity, simply because I am no artist)

[neuro]

In any case, in consideration that reading sheet music involves language translation to action, it seems not all the activity is related to conditioning the fingers to play by themselves, so to speak. Some cerebral energy would require devoting oneself to reading the music. Indeed, this may require considerable concentration.

Still, as the proficiency of a musician grows, the connection between the drawings on the sheet, the resulting music and the psychomotor procedures involved in playing it becomes more and more direct, and requires less and less involvement of the conscious (or cognitive) activity.
On the other hand, don't you hear the sound of a word (with no "conscious energy") when you just see the characters wich constitute it, printed down?
Until this happens, you wouldn't say one can really "read", would you?
(gee, I realize you may interpret this as me saying that you can't really "read" music... I'm afraid I went too far, this time... :°)

[owleye]

On the other hand, don't you hear the sound of a word (with no "conscious energy") when you just see the characters wich constitute it, printed down?
Until this happens, you wouldn't say one can really "read", would you?
(gee, I realize you may interpret this as me saying that you can't really "read" music... I'm afraid I went too far, this time... :°)

Actually, no. What I believe I'm doing by reading notes is converting them to actions by my fingers. It's true that I can hear mistakes (though because I'm a bit hearing impaired, it works better with earphones on my electronic piano), but this I consider feed back. I guess the sheet music should be considered a kind of crutch, but, I've never been successful in getting rid of it even for a single piece of music. In my latest attempt, I tried to memorize the first theme of the second movement of Beethoven's Sonata #8. It is not a particularly difficult passage and with the sheet music in front of me, I work my way through it rather easily. My fingers seem to remember how to play it, and I've even a few times attempted to play it without this help, sometimes even successfully. However, it doesn't take much for me to lose it. (This is true also when reading it from the sheet music.) A simple lapse of concentration (or alternatively, too much concentration), and I forget where I'm at or what comes next. Indeed, if I have to look down at the piano to strike a note, I may lose my place. Turning a page is also a problem and I've noticed that some who read music memorize what's on the next page before eventually turning it. I do this to some degree, but I can't get very far before I don't remember what comes next.

If I look in greater detail where my problem is, let me acknowledge that my fingers know better how to play it than I do. So, what happens is that as I let go of trying to guide my fingers (letting them do what they have learned to do), they do play what they've learned and I presumably can reach for a higher level of music making. But what really happens is that I hear all the mistakes I've made -- not hitting the keys precisely, or inadvertently touching an adjacent key, or (because of fat fingers) not being able to prevent hitting adjacent keys, or any of a number of ways of performing badly -- I wind up having to intervene (which typically throws off what my fingers have learned), or sometimes I ignore what I'm hearing and go with its flow instead. Perhaps the question is which should be done first, performing it well, or memorizing. One problem with the latter is that the fingers might be memorizing the piece wrongly (mixed up fingering), and if one memorizes too soon, one may never be able to play the piece correctly. (Well, maybe not, I don't know.)

James

[psionic11]

Once you can play the piece fluently without your fingers getting mixed up, then in my opinion you've learned correct enough fingering. Since we now can say that what we traditionally called finger or hand memory is likely nested in the cerebellum, you can then separately approach the goal of playing without sheet music and with more of a detached artistic director approach using your cortex.

Quick side story regarding letting the fingers do their own thing -- a long time ago while noodling on my acoustic guitar around age 18, I found myself daydreaming about something. My mind must have wandered for a good 30 seconds, and when my attention came back around to my fingers, they were still playing!! It dawned on me and shocked me that for that whole 30 seconds they were playing as if they had their own mind! I was outside looking in. Just one more anecdote into the dissection of consciousness.

[neuro]

Well, owleye, it seems you are clearly aware that two profoundly different processes are involved, characterized by different modes and features, and carried out by different structures and circuits.
In memorizing the sheet music, we use explicit memory circuits (hippocampus+cortex) to store a sequence of symbols as we would store any other sequence of data, possibly with the help of similarity or evocative links among the symbols. Some use some more of a visual memory, and kind of memorize the images of the pages themselves or of groups of notes as complex drawings. In memorizing music the whole thing is facilitated by memorizing the melody as well, as an auditive stream, and by moving in the frame of harmony.
Memorizing the performative aspect (let your finger learn to play the piece), on the other hand, is a psychomotor learning task which is performed by a wonderful interacion among cortex (guides the motor behavior), the cerebellum (corrects by feedback control and gradually learns to execute) and the basal nuclei (prepare subsequent movements and smoothly link the movements so that the motor scheme is performed in a fluid and harmonic way)

When you play, then, the brain is only supposed to inject the motivation to acting, supervise and tell what's next, take care of interpretation (crescendo, pianissimo, etc) and possibly put a bit of soul into it. But if it tryes to do more, then it jams up the whole story, because it is slow and imprecise, whereas the cerebellum is fast and particularly precise (thank to real-time feedback in the hundredth-of-second scale).
Still, you are right: until performance is adequate, the brain has to intervene when an error occurs and everything gets jammed. I think this is why when you learn under supervision of a teacher he will have you play over and over each single phrase where you happen to make an error, to avoid the problem you point out that "your fingers" might "memorize" the wrong procedure. I think this procedure might also help in memorizing, as you end up memorizing the sequence of "blocks" (what comes next), which are singularly well known, rather than the whole sequence.

Anyway, you have all my sympathy, because I have always dreamed myself I could have my finger correctly move as I read music, the same way my tongue and larynx correctly move when I read words. But that seems to be a not so common gift (or possibly we did not practice enough...)

PS sorry, psionic11, I see now your post (I was writing offline), so my post may interrupt the flow of music ... :°)

[psionic11]

Music sometimes flow, sometimes introduces sudden new elements.... much like life =)

Don't know if a new thread needs to be started, but I'd like now to catalog the various brain centers' functionalities.

cerebellum
storehouse of rehearsed and commonly orchestrated muscular movements, like swinging limb to limb in trees or swimming or acrobatic maneuvers or finger memorization/automation of musical parts

basal nuclei
preparation of pre-programmed movements, resulting in smooth flow from process to process

substantia nigra
dopamine heavy centers, involved in reward/learning

anterior cingulate cortex
center involved in monitoring general expectations, and alerting other cortical areas when something unexpected happens

pituitary gland
regulates hormones

hippocampus
memory

hypothalamus
memories


I would post more, but I find this forum reply box VERY IRRITATING as it doesn't scroll down and makes it difficult to make lengthy posts because it always scrolls the view back up away from what you were last typing....grrr