ashennell

Hi, it really depends on your background. Neurosience these days is a very multidisiplinary area. There are numerous different levels at which can study the brain. I would recommend 'Essentials of Neural Science and Behaviour' by Kandel, Schwartz and Jessell - I think there are a view different versions of this book. You should read a couple of good psychology texts as well, maybe someone good suggest a good one. The distinction between neuroscience and psychology is rapidly decreasing - in my view anyway. Background again. Neuroscience can be studied at a purely biological level but it you are interested in 'how the brain works' then you really need focus on higher level interpretations. I would recommend some serious maths revision starting with linear algebra, stats and information theory, optimisation, dynamic systems theory and probably a whole bunch of other stuff. I guess it would be usefull to read a few 'philosophy of the mind' books as well to provide some kind of overview. Most neuroscience researchers will already have exprience with maths, biochemistry or physics. It really does depend on where you are coming from and what you want to achieve. If you can tell me that then I can suggest what to do next. Its a big subject. Edit: spelling

I should add, sorry, that if we assume: hallucination = brain making mistakes. Then any method of attaining a hallucinagenic state is probably not good for you.

Try staying awake for 3 or 4 days at a time. That is prety much guaranteed to induce some sort of hallucinations.

Sunspot - you are now spouting drivel. This last post about memory makes no sense at all. Reverse suggested that you present things clearly - I think this is good advice. Don't just keep posting long, confusing explanations of ideas that you have clearly made up with no regard for current knowledge. Try reading a few psychology books. You will realise that your ideas so far can be split into two categories : 1) something that someone else has explained better previously, 2) nonsense. Sorry, but that is how it is.

I can't say for sure without a quick review. I'll have a quick look at the data over the weekend and get back to you. However, there is one problem I can foresee, Scientists are kind of limited in what they can show people in a MRI. Also, I think that a picture of an apple will provide different activation to a real apple. Data from electrode studies is not going to be too useful in answering this - I guess. There must be some difference between viewing a real scene and imagining it but for the vision to 'mean' the same (or similar) as the real input it needs to recreate some of the same patterns of activity in the same parts of the brain.

I have met many people who believe the old 10% myth. I always try and convince them that it is indeed a myth. However, in the cortex the vast majority of the cells are support cells that provide insulation to the neural processes and help with biological functions rather than computational ones. So in some sense it might be accurate to say that only 10-20% of the cortical mass is used for coputation although I doubt this is equivalent in any sense to what people mean when they spout out this particular urban legend - it is still functional. It seems clear that sunspot means something different, conscious versus unconscious processing. I would prefer to use the terms attended versus non-attened processing. This distinction seems to be a fundamental consequence of the mode of operation of the thalmocortex. However, measuring the percentage or attened versus un-attended processing is probably not a useful way of understanding what is happening. These two types of processing are not separate at all - more like the opposite sides of the same coin. There are some nice little experiments that show that we constantly revise our own memory of what we have just been conscious of anyway (see Dennet) so you can't really be sure of your own subjective experience. However, you are right about automating sequences of actions and perceptual chunking - procedural learning basically. This seems to occur in the cortex and not just in the cerebellum. It is also thougtht that the basal ganglia is inportant in organising our action sequences. I'm not sure what a ego terminal is. Is it not just a desktop for your homunculus?

I have an opinion about this rather than a definate answer. I think that the cortex is optimised for dealing with sequential information / temporal structure. It seems our motor system is organised into a repertoire of automatic behaviours - learned sequences of actions. I believe perceptual chunking and cognitive chunking are a result of exploiting predictable sequences of events - dependancies between events. Converting data into a narrative can improve memory consolidation. Anyway, the point, data presented in a format that can be easily converted into sequential patterns is probably easier to comprehend. Honestly - no, not at all. If we visualise a house the visualisation occurs in the visual cortex. The information does not need to be transfered to the PFC for us to perceive it. This seems like a hang=up from the old cartesian theatre view (although this often occurs without realising it). Once we have one part of the cortex to represent something there is no point shifting it elsewhere to represent it again. If we were actually looking at a real house, our visual areas would contain house-related info, what would the PFC be doing? Well, in the visualisation of a house we are essentially trying to partially recreate this situation. Maybe this is not clear. If you are visualising a house there is probably a good reason, maybe the PFC is processing info about the reason.

Hi, sorry I've been busy. The results you refer to in your first post are correct. The motor and perceptual parts of the brain are indeed active during visualisation, thinking, imagining or what ever else you want to call it. As for abstract thought - the situation is not so clear. I have seen some evidence, from language research, that would suggest that abstract thought is given a spatial representation or some way interpreted in terms that are similar to the constraint placed on our perceptual systems. e.g. graphs are sueful for visualising functions. I'm seem ot recollect that many of the great scientists relied on a good visualisation of the problem in order to solve it. I'm sure that the PFC is critical in abstract thought but I think that by interpreting abstract ideas in this way would allow other cortical areas to become involved.

Algorithms run on turing machines. Not all algorithms are eqivalent to turing machines. The brain is NOT equivalent to a turing machine running an algorithm but it is deterministic (probably) and therefore can be converted into an algorithm and run on a turing machine itself. The Church-Turing thesis, put simply, states that any algorithm (that satisfies certain requirements) can be ran on a turing machine equivalent device given sufficient time and storage. It also states that these computers have equal computational power. Undecideability, the halting problem etc., is not really an issue for the brain in my opinion. It seems to assume that the main function of our nervous system is to determine the truth of paticular statements or act as a theorum proover or something likewise. It is strange then that most people are pretty poor at abstract logic problems. The way that most people model nervous tissue at the moment is by using sets of dynamic equations (plus other bits and bobs) so we could compare thi s kind of simulation with weather forecasting programmes. I assume that they use dynamic equations. If we imagine a huge wheather forecasting computer where in particular would undecideablilty come in? I think it's a lot easier to ignore that brain performs cognitive tasks and think about it instead as a non-linear dynamic system.

The effects of alcoholo nthe Nervous system are quite complex. Primarily, it increases the fluidity and permeabillity of the plasma membrane. Ion channels, involved in neurotransmission, are also effected by ion channels. This rather general mechanism means that alcohol could modulate the function of many different transmitter systems. The effect on GABAergic trasmission has been well studied. Alcohol activates the GABA-A receptor-coupled Cl- channel. This, as has already been mentioned, potentiates, GABAergic transmission. Many of the effects of alcohol can be explained through it's effect on this transmitter system. Alcohol does seem to influence other transmitter systems. In particular, cholinergic and serotonergic transmission is enhanced and NMDA-dependant glutamatergic transmission is reduced. Alcohol also effects mesolimbic and nigrostriatal dopamine transmission. It seems that cronic alcohol intoxication down-regulates the DA systems. I also believe that there is some interaction between alcohol and the opioid system.

I think you are mistaken here. If the brain is deterministic then is can be simulated on a turing machine but this doesn't mean that it is equivalent to a turing machine. Undecideability is not an issue here.

So, can we just be clear here Bascule, you argue against any form of quantum theory of consciousness but support the idea that consciousness on mass can effect quantum random number generators at a distance? So there is a connection between consciousness and quantum processes outside the brain but not inside? Both suggestions are highly speculative at best but for some reason you dismiss one from the start and yet support the other, the evidence for which is not widely supported inthe academic world. Dick Bierman, who is involved in this GCP, is also a proponent of quantum explanations of consciousness and it would not suprise me that many of the others are too - given the effect they are investigating. Perhaps you would like to update the wikipedia as the same criticisms have been levelled there:http://en.wikipedia.org/wiki/Talk:Global_Consciousness_Project Does this mean that quantum computation research is a waste of time? What point is a computer if its bits get flipped every time you think too much?

Quite coincidentally, I have a meeting tomorrow with a non-scientist (arty type) who is collaberating with one of the people involved in this project. I think I'm suppost to go and tell them why it is a load of rubbish - im not really sure. Anyway, perhaps I will be able to find out a little more detail. I was going to critise this research but just read the link instead it basically sums up my opinion: http://www.skepticnews.com/2005/02/rednova_news_ca.html

I think this seemed important at it's time but not anymore. Trying to understand the brain as turing equivalent is pretty pointless. I think the most promising approaches that we have for representational learning stem from empirical bayes, infomax, predictive coding and the like, all of which come under the umbrella of expectation maximisation algorithms. There has been some fantastic papers recently concerning the implementation of these methods in reasonably biologically plausible ways. I think Bayes will be at the centre when all is said and done. Dynamical systems theory is also becoming a mainstay of computational neuroscience research. I read an interesting paper recently that suggested that recurrent networks would need to stay near the critical border between chaotic dynamics and ordered dynamics to perform computations on time series. I think this type of analysis is still in it's infancy with regard to neuroscience but I think it will have a lot more to offer. I think that most of the models can be organised into related groups. There are way too many though and analysis of neural nets has always lagged behind the creative part. Connctionism has rediscovered numerous mathematical techniques with even realising it. Symbols... Well this is a different discussion but I'm not convinced that the brain is a true symbol manipulator at any level of analysis. There are some good arguements that it probably is (Fodor etc) but no proofs that it must be. Agreed.

I agree with your opinion about quantum consciousness theories here but why do you invoke this in response to a suggestion that the brain is essentially determinisitc. Is the only contribution or addition from quantum theory a means of avoiding determinism. If so, then it is useless, just an addition source of noise in the system. We don't need anything other than deterministic processes to describe behaviour, determinsitic processes can generate psuedo random behaviour, complex enough that it is unpredictable. I think gib65 is right here, we could have an artificial brain and still not be able to prove that it is conscious. I think we would feel that there was something missing even if there was not. Fine, one day we will be able to describe the brai nas a set of dynamic equations, learning rules, etc., etc. but which ones exactly make consciousness. Which intrinsic part of the processing procedure results in subjective experience. I dont' think we will need to add something to create consciousness but I don't think we will be able to prove that it is conscious either. This is just not true. There is still plenty of things that we still don't understand at every level. We have little idea of how the brain deals with motivation or motivated behaviour for example. The quote you provide describing CorticalBD is a perfect example of our lack of understanding. If we really understand what the brain is doing why are we busy coping the intricate details of neuron types? Because we don't really know which features mean what and which are irrelevent. It is a fantastic research tool but I'd much prefer a set of principles that explain wht the cortex is doing. This is an association between two different phenomena and not and explanation of the relation. It is almost like denying that the problem of explaining consciouness exists at all.

Many textbooks actually describe Shannon's information as equivalent to suprise given that it is inversely proportional to the probability of an event occurring. However, this measure of suprise is not context-dependant (subjective). I think that the conditional probability has been used to obtain context-dependant measures of information but it would seem logical to make use of Bayes theorem. This seems to be what these people have done. I've had a quick look what they have done seems to make sense. They are using the Bayesian framework for reasoning with uncertain information. In the Bayesian framework the prior probability distribution represents our expectations 'prior' to observing an event. They are measuring suprise as the change in this distribution following the observation of an event.i.e the extent to which an observation changes our expectations. Thanks for posting this , it's something I should definately read. Once I've had a proper read through maybe I will be able ot make complete sense of it.

Perhaps we would label them as radical or eccentric but certainly not schizophrenic (not these days anyway). Schizophrenia is a clinical condition and not just having an unconventional viewpoint. Postmortem of a schizophrenics brain shows substantial deteriation of a large number of neural structures I doubt this is likely to result from just being non-conformist. From the information provided so far in this thread it would seem that this is not the accepted scientific view. Why is there this need for people to defend marijuana? The fact is at the moment we just don't know exactly what it's effects are in the long term. This means that any arguement that condemns or supports marijuana use is just propaganda and is baseless. This applies equally to either side of the arguement. I think people should be able to decide for them selves on this issue but should be able to make an educated decision. Claining marijuana is risk-free is as dishonest as claiming it to be at the root of all that is wrong in the western world. I agree with this at least. The idea that pot smokers contemplate these issues more than other people is nonsense. So assuming they develop there own logic structure, is this because they have competently covered all the relavant issuses from every viewpoint and come to a sound logical conclusion or is it just a lazy way of self-validation through dismissing other peoples values. When people claim that the majority play 'follow the leader' the emphasis is that the majority is wrong , what exactly they are doing wrong is secondary. western civilisation is far from perfect but I doubt the solution lies in dissociation from the environment or smoking more pot.

Honestly? I think that the neurosciences takes a qiuck look and then runs away in the other direction. I'm not sure if there is any solid science behind any of these statements- not any I'm aware of anyway. I would be interested to be pointed to something I could read to support this view - something based on actual data. I believe that lateralisation in the brain is complex and certainly does not occur the absolute sense depicted above. Allthough I'm not denying that there is lateralisation to some extent. I would think that the lateralisation of language comprehension and production is the most extreme example and may be the driving force behind other hemispheric differences. Hemispatial neglect can occur on either side with equal effect so this would suggest that any hemispheric bias on consciousness is limited. While this is true, it is also true for everything else that the brain does as well. Parts of the brain that are known to be involved in emotion include the amygdala, the anterior cingulate and orbitofrontal cortical areas, the hypothalamus, and the hippocampus. These areas are linked together as the limbic system. Ventral parts of the striatum, in particular the nucleus accumbens, are also involved in emotional / motivated behaviour. The link between any particular neurotransmitter and a particular emotion is tenuous at best. Serotonin, for example, is linked to regulation of feeding behaviour and agression. The activity of serotonergic neurons of the raphe nuclei is closely correlated with the arousal state of the animal in question. The firing rate is highest during active wakefulness, lower during slow wave sleep and abolished in REM sleep. The activity is also increased during repetitive movements or habits. SO the point is - that serotonin= happiness is a serious over simplification. This is equally true for any other nuerotransmitter system. I think that happiness is probably a term applied to a number of different actual mental states. Is happiness just being content with your life or is it an intantaneous feeling induced by your immediate surroundings. Happiness can be linked to relaxation, the absence of stressors, humour, love, good intellectual discussion, etc,etc. I'm not so sure that it is the same thing in each of these instances. What I am trying to say is that I don't think that happiness is just a single variable that can be high or low - it is more complex than that.

Ah ha, now it is perfect. Interesting ideas bascule, I can follow the reasoning all the way throught but at the end you say that everything will revert to chaos. This dosn't seem to come from the principles that you have used for all that came previously - So why this final step?

Any drugs that effect neurotransmitter systems are very crude, very far from ideal medical solution for the conditions that they are designed to alleviate. Basically they are neuropharmacological sledgehammers. --- Addiction and anxiety/depression are intelligent enemies - they use your brain against you. Examples that seem to be suitable to this discussion would be: Treating temptations to drink during a course of drugs as proof that you cannot beat your addiction. i.e. playing on expectations of how well the drugs will work. Telling yourself that you are stong enough to not need the treatment so you stop taking the tablets knowing that if you relapse you can blame the lack of medication instead of the lack willpower. Emphasising the side effects of the medical so they become 'worse' then the addiction itself. etc.,etc., I think pharmalogical treatments need to be balanced with councelling as well as a personal understanding of what addiction is and how it will work against you. I guess the second pert of this post comes more from my personal experience than from a science textbook.

I can't believe that you didn't find a way to fit the word 'singularity' in there somehow bascule. Very disappointed.

I want to try and disect your post to try and get at what you are talking about. As others have suggested, highest or most evolved dosn't make sense. the sucesses of evolution are those species that are closely adapted to survival in their niche.Our general problem solving skills or 'intelligence' is just one solution the the survival problem. What do you mean by potential? potential energy, membrane potential or some other potential ? what potential would the different forms of non-brain matter be at? The branching structures of neurons? Do you mean dendritic structure or axonal branching. different types of neurons within the brain have very different branching patterns and these patterns are reasonably similar between speicies. So what particular neuron types are you talking about, local circuit neurons, cortical pyramidal neurons, granular neurons, thalamic relay neurons? What do you mean by higher curvature, I really dont get that, parhaps you could expand on this. You use the term surface potential - I assume you mean the resting potential of a neuron - the electronic gradient between the intracellular and extracellular spaces. . Are you still talking about surface (resting) potential? Or are you now refering to some kind of behavioural potential? If you are talking about the physiological resting potential then this statement is not true. This potential word keeps cropping up! It kinda feels like you are trying describe a theory of the brain in terms of a function of one variable - potential. Can you elaborate a little on this theory and perhaps provide a concrete definition of brain potential.

Sorry, I meant to do put this in my last post. As far as I am aware the genetic data applies to all types of schizophrenia. The use of the Kraepelin subdivisions (catatonic, paranoid, hebephrenic and simple) does not seem to capture any consistant differences in terms of abnormalities, neurological changes or etiology. This is my understanding of the situation but I am happy to be corrected if someone else knows better. As for genes - i think an area on chromosome 22 has been associated with schizophrenia but not a gene and this is not definate.The pseudoautosomal region on the sex chromosome may also be involved.

The general population have a life-time risk of about 1% 1st-Degree relatives of a Schizophrenic have a life-time risk of about 12% 2nd-Degree relatives have a 4% risk. Concordance for monozygotic twins is 48% but only 17% for dizygotic twins. However there is some evidence that factors in the prenatal environment could contribute to these high monozygotic concordance rates and hence lead to overestimation of the genetic component or heritability in schizophrenia. if a condition is not completely detemined by the genetics then there would be not reason why two identical individuals should both develop it. While we are talking about Schizophrenia and drugs - PCP intoxication is apparently indistinguishable from an acute episode of schizophrenia and is know to intensify the primary symptoms of schizophrenia.

This would seem to require that consciousness came before life (amongst other revelations). Yes, I think that telepathy and precognition are all down to co-incidence and the brains ability to obtain more information from the environment than we are consciously aware of. Yes, this is quite a common parapsychological approach. They use electronic random number generators and ask a subject to try and wish the numbers to be either higher or lower or something. I think a number of these studies have been published in parapsychology journals that show that biasing of random number generation does occur in this situation. However, I am of course very skeptical about this kind of research and I recently had the opportunity to read one of these papers. It was pretty terrible - there was insufficient detail to allow the experiment to be repeated, parts sounded confused and jumbled. Basically, I was suprised that this kind of junk could be published at all.