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Quantum Mind Blog'Once we have bitten the quantum apple, our loss of innocence is permanent.' - R. Shankar RECENT BLOGS:- 7 February 2012 Dopamine and motivation 30 January 2012 Argument for the physical nature of free will 26 January 2012 Mathematical problems with inflation theory 25 January 2012 Despair with popular science treatment of consciousness 17 January 2012 Test for quantum entanglement 9 January 2012 Machine consciousness 6 January 2012 Consciousness and executive function 4 January 2012 Consciounsess as crosstalk mechanism 22 December 2011 Protophenomena 21 December 2011 Flexibility of preferences 20 December 2011 Predicting emotional reactions 19 December 2011 Neurobiology of preferences 18 December 2011 Subject-driven cognitive states 17 December 2011 Quantum boundary 16 December 2011 Quantum biology prospects - 2012 8 December 2011 Pressure for multiverse orthodoxy 6 December 2011 Self-only consciousness 29 November 2011 Implications of anaesthesia Older blogs in Archives 1 to Archive 16 7 FEBRUARY 2012 DOPAMINE AND MOTIVATION The influence of dopamine in generating action from motivation Mark Walton, Jerylin Gan & Paul Phillips Neural Basis of Motivational and Cognitive Control - MIT Press (2011) Keywords: dopamine, midbrain, basal ganglia, nucleus accumbens, opioid neurotransmitters INTRODUCTION: The release of dopamine into the striatum and particularly the nucleus accumbens is closely related to the subjective evaluation of sensory inputs, and to the subsequent selection of behaviour and actions. The authors start by referring to a distinction between the evaluation of reward, and the process of deciding to obtain, and then acting to obtain a reward. It is suggested that much twentieth century research fell short in not paying attention to the internal motivation of subjects. The authors acknowledge that several regions of the brain may be implicated; their emphasis here is concentrated on the striatum, particularly the nucleus accumbens and also dopamine projections. The dopamine projection to the nucleus accumbens come from the ventral tegmental area (VTA) in the midbrain. Dopamine is a modulatory neurotransmitter often associated with the modulation of the excitatory neurotransmitter, glutamine. There is particularly dense innervation of the striatum by dopamine. Release of dopamine and availability of dopamine receptors in the nucleus accumbens is associated with drug addiction and also with compulsive shopping, eating and gambling. A good deal of past research has concentrate on the role of dopamine in the selection of isolated rewards, rather than the more realistic situation of subjects assessing competing rewards and associated uncertainty as to the costs and probabilities of obtaining particular rewards. Recent studies, however, point to a correlation between the firing of dopamine neurons and the size and probability of particular rewards. Some studies also suggest a connection between dopamine activity and the timing of future rewards. Dopamine is seen as important in allowing the subject to exert the effort needed to obtain a particular reward. Dopamine release is viewed by the authors as facilitating, but not controlling, responses that seek potentially costly rewards. It is seen as a motivation to seek novel options and potential future rewards. Evidence suggests that dopamine is involved in signalling the availability of reward. This is partly related to the prediction of reward, but also to actions directed towards gaining rewards. Additionally, the release of dopamine from the VTA can increase the probability of a reward being sought. In situations where there is conditioning, dopamine release can change from being directly related to the arrival of the reward, to being merely something that predicts the future probability of the reward. Dopamine activity can also increase where a reward is either above or below the predicted level, being thus an indicator for error predictions. The authors see dopamine in the nucleus accumbens as being important in making reward predictions when the subject is encountering an uncertain environment. However, this is viewed as only one influence on the subject's actions. 30 JANUARY 2012 ARGUMENT FOR THE PHYSICAL NATURE OF FREEWILL Where has your willpower gone Roy Baumeister, Florida State University New Scientist, 28 January 2012 Keywords: Free will, will power, self control, emotions, neurotransmitters INTRODUCTION: It is quite encouraging to find Baumeister writing on free will or self control in a popular science magazine, given that as a psychologist, he is a long way from the mainstream's reliance on a simplistic interpretation of the Libet experiments. Although the article is given a rather reductionist spin, stressing that will power is driven by glucose based energy, its arguments are fatal for the deterministic establishment view as to the non-existence of free will. In contrast to the mainstream view that there is no such thing as free will, with unconscious and deterministic computations responsible for all human actions and behaviour, Baumeister argues that free will or self control requires energy, and is therefore part of the physical processing of the brain, rather than an illusion as the mainstream would have it. Baumeister states that research demonstrates that when subjects have had to exert self control, they perform poorly on a subsequent test of self control. It is argued that energy is depleted by the first exercise of self control leaving less available for the second attempt. In one such test, subjects were left next to a table with chocolate biscuits, which they were not supposed to eat. Some of the subjects succumbed to temptation and ate the biscuits. Subsequently, both the subjects who had succumbed and those who had resisted attempted a puzzle, which unbeknown to them was unsolvable. Those who had resisted the biscuit temptation gave up sooner on the puzzle, suggesting that their mental energy had been depleted by the effort of resisting temptation. In this context, will power is compared to a muscle that can tire, although its full energy can return after a period of recuperation. Baumeister proposes that the energy driving will power is ultimately based on glucose that is the basis of neurotransmitters instructing axons to fire. A meta-analysis performed in 2010 showed that as in the tests mentioned earlier, subjects' performance deteriorated between a first and second self control test. However subjects dosed with glucose after the first test performed well on the second test. 26 JANUARY 2012 MATHEMATICAL PROBLEMS WITH INFLATION THEORY Death of the eternal cosmos Lisa Grossman/based mainly on Alexander Vilenkin New Scientist, 14 January 2012 The fashionable theory of eternal inflation at the beginning of the universe has been used to explain both the fine tuning of the laws of nature and to allow for string theory having 10500 solutions. Alexander Vilenkin of Tufts University has examined the equations relating eternal inflation to the Hubbke constant describing the expansion of the universe in Physical Review Letters, DOI: 10,1103/physrevlett.90.151301. The conclusion is that it is impossible to have a spacetime with this property, as the constant has a limit that prevents inflation. The same sort of constraint applies to the idea of cyclic universes going through endless Big Crunches followed by Big Bangs. From this Vilenkin concludes that there is no possibility of a universe that did not have a definite beginning. 25 JANUARY 2012 DESPAIR WITH POPULAR SCIENCE TREATMENT OF CONSCIOUSNESS Perhaps we should despair of modern consciousness, studies or at least ban it from appearing in popular magazines. A quarter century on from the lifting of the complete taboo on mentioning consciousness in scientific circles, a popular article in a popular science magazine (which often does good stuff on other subjects) can come over as a mixture of error, misrepresentation in the early stages, followed by a move to peripheral topics which could never by themselves explain consciousness. The first part of the article takes the familiar route of looking at Penrose's ideas, and then quickly demonstrating how they are wrong. Except unfortunately that these arguments are also in error. The ancient argument that microtubules can't support consciousness because they are present in all cells in the body and not just neurons is trundled out. While much of consciousness studies is painfully complex, here there is a simple answer, to the effect that microtubules are denser and more stable in neurons, making them more suitable for information processing than the cells in the rest of the body. Not content with this, the article goes on to make a double misrepresentation as to why quantum consciousness theories are unpopular. The article correctly states that 'almost everyone researching consciousness rejects the quantum computing theory' but misrepresents the reason for this. It is claimed to be because invoking one mystery (quantum theory) to explain another (consciousness) gets you nowhere. This lets down the less well informed reader, for the reason that Penrose never proposed that because quantum theory was a mystery, it was a good basis for explaining another mystery. This was a criticism, or rather just a piece of ridicule coined by the philosopher, David Chalmers, in the 1990s, but tirelessly repeated by the more superficial critics of quantum consciousness. In fairness to mainstream consciousness studies, there are more serious reasons for arguing against quantum consciousness, but these are not touched on in this article. Another misunderstanding here is the suggestion that Penrose's theory was proposing neural correlates of consciousness, whereas it was proposing the basis of mathematical understanding later extended to cover consciousness itself rather than a correlate, which is simply a feature found in the same times or places as consciousness. There is, an in itself interesting, section on building up knowledge of which brain areas react to which images an actual image of what the brain is looking at. This is a tremendous tour de force technically, but tells us precisely nothing about why these brain activities produce consciousness. Having whiled away a good deal of space discussing potential correlates of consciousness, the article ends on a curious note. It is suggested that scientists will never find the correlates of consciousness. Why? Because, we are told, there is no difference between conscious and unconscious processing, and as a result the whole idea of consciousness, or possibly just the idea of consciousness being a problem (which of these isn't really clear) is a function of muddled thinking. This seems wrong on first principles, because we know that some systems of activity in the brain are necessary for consciousness, (for instance the global gamma synchrony) and systems of activity lacking this are not conscious. Being conscious is a different for the subject from not being conscious and is produced by different systems of activity (as opposed to specific brain areas referred to in this article), and on this basis it is impossible to refer to the two as being the same. 17 JANUARY 2012 TESTING FOR QUANTUM ENTANGLEMENT Persistent dynamic entanglement from classical motion: How bio-molecular machines can generate non-trivial quantum states Guerreschi, G., Cai, J., Popescu, S. & Briegel, H., Universities of Innsbruck, Ulm and Bristol arXiv: 1111.2126v1 [quant-ph] 9 Nov 2011 Keywords: quantum entanglement, quantum error correction, thermal equilibrium INTRODUCTION: The authors' model studies the cyclic regeneration of quantum entanglement in hot systems. This looks to open the road to modelling or even experimental simulation that would constitute a possible test for/falsification of non-trivial quantum states in proteins such as those found in neurons. The paper refers to a simple mechanism by which a molecule forced out of thermal equilibrium by oscillations, can sustain quantum entanglement. This type of entanglement can survive intense noise, but cannot survive if the oscillation ceases. This is argued to be the basis for non-trivial quantum entanglement in biological matter. The authors remark that this reverses the previous orthodoxy, which held that quantum effects could not exist in biological systems because of the amount of noise in these systems. They note that research in photosynthetic organisms have undermined this case in recent years. The existence of entanglement in a system is seen as greatly increasing information processing capacity, and this underlies the potential of quantum computing. It is pointed out that the previous orthodoxy was based on the assumption of thermal equilibrium, whereas biological systems are open and driven systems far from thermal equilibrium. Such systems are suggested to be capable of quantum error correction that could sustain longer-lived quantum entanglement in biological systems. In a 2010 paper in Phys Rev E (1.) the authors presented a mechanism by which a molecule subjected to non-thermal equilibrium oscillations could sustain entanglement between two states. This could be maintained despite a level of environmental noise that would not allow entanglement to persist in the absence of non-equilibrium oscillations. Protein molecules, which undergo conformational changes are suggested as the sort of environment in which quantum entanglement of the type found in this model could arise. In the first section of their paper, the authors look at the possibility of entanglement generated by molecular motion. A biomolecule undergoing conformational change can lead to an interaction between different sites of the molecule. The conformational changes of the molecule can force localised spins to come close or move apart. With the molecular configuration oscillating in a periodic way, cyclic regeneration of entanglement can be sustained over long periods of time, despite noise that would make static entanglement impossible. With thermal equilibrium, entanglement becomes impossible above a certain temperature. The authors, however, ask what happens when molecular motion is involved, and seek to demonstrate that entanglement can keep recurring in an oscillating molecule despite a hot environment. The authors consider a simple process, with spins that are far apart and with an interaction that is weaker than the surrounding field. In this state, there will be no entanglement. When the spins approach one another entanglement can appear transiently on time scales shorter than that required for thermalisation. The molecule is seen as being kicked out of thermal equilibrium. The generation of entanglement depends on the rate of thermalisation not being too fast. The sustained recurrence of entanglement requires a persistent supply of free energy that can be produced by the conformational changes of the protein. In the author's model the background field predominates when the spins of the particles are widely separated, but when they are close together their interaction predominates. The authors assume that two spins start far apart and are in a state of thermal equilibrium. The spins oscillate, move closer together, are driven out of thermal equilibrium, and entanglement is generated. Environmental noise here drives a persistent and cyclic generation of new entanglement. The periodic oscillations are seen to keep molecules far away from thermal equilibrium, with the continuous change in the shape of the molecule preventing thermalisation. The authors emphasise the constructive role played by thermalisation. In a hot thermal bath the first oscillation of the molecule is lost more quickly than in a cooler environment. However, the pumping of energy is seen to provide a reset mechanism. In discussing biological systems, the authors consider that chemical interactions would serve to keep the system out of equilibrium. But in gaps between chemical activity, equilibrium could return, and entanglement would therefore be transient. In summary, the authors say that they have demonstrated that entanglement can recur even in a hot noisy environment. In biological systems this can be related to changes in the conformation of macromolecules. The authors say that this modelling is a route by which to search for the signatures of entanglement in biomolecular systems. They also think that existing technology could provide an experimental simulation of their model. This could possibly amount to a test for/falsification of the hypothesis that non-trivial quantum states act within proteins, and thus test related theories of consciousness. 9 JANUARY 2012 MACHINE CONSCIOUSNESS Can machines be murdered? Tate, M.A. et al Keywords: consciousness, artificial intelligence INTRODUCTION: This chapter in 'Consciousness and the Universe' emphasises the lack of depth of thinking that can be seen as a hall mark of the functionalist approach to consciousness theory. The first sentence makes the assumption that particular actions or more especially the combining of particular actions will produce consciousness. Characteristically in this sort of writing, no argument is presented, and conclusions are merely asserted. Computers/robots are making advances in mobility, face recognition and other functions. It is not clear whether the authors think that a machine performing just one of these functions could become conscious. At any rate, their main emphasis appears to be concentrated on generating some magic out of the combination of different modalities that occurs in the brain, although this point isn't really clarified. Relating consciousness to the combining of modalities has a certain plausibility in respect of recent neuroscience, in that consciousness in the brain is correlated with the global gamma synchrony extending across regionally located modalities. It is possibly awareness of this arrangement in the brain that has suggested that combining a number of functions could produce consciousness, although again this neuroscience background is not discussed or even mentioned. A general problem relating to this suggestion is that the synchronisation of action spikes across billions of spatially separated neurons bears little resemblance to computing. Although functionalism is probably still the dominant orthodoxy, there is now more of a ground swell of awareness of the differences between computers and brains, and the authors do feel it necessary to address these reservations. They seem to put forward the argument that the operation of the gamma synchrony could be digitally replicated, although this isn't really clear. No doubt a computer could in principle replicate such connections, but this leaves open the question as to whether the basis for consciousness in the brain relates to the connections as such, or the physical/biological structures that allow them. This could be a subject of some discussion, but no discussion appears to be considered necessary in this chapter. A further problem here appears to be that the working of human-made computers is fully understood, and provides no examples of structures that do not exist elsewhere in the universe without them producing consciousness. On the other hand, our understanding of the brain and more especially the neuron's complexity at the microscopic level is less certain. It is noticeable that while philosophy and psychology talk in terms of certainties with relation to the mind, the nitty gritty of neuroscientific literature is hedged by 'perhaps' and 'could be'. Furthermore, the gamma synchrony, as is admitted even in the most conventional circles, is only a correlate of consciousness. Is it consciousness that produces the synchrony, visa versa or some interactive process between neurons and the brain-wide synchrony? Mind-brain identity: The writers are also supporters of mind-brain identity. The core of the mind-brain identity concept is that mental states and neural states are identical. In a trivial sense this appears to be true of all theories of consciousness that are not dualistic, so that even a Penrose-Hameroff theory of consciousness could be argued to be a mind-brain identity theory. Thus Penrose argued that the mind was not identical to a computer rather than not identical to a brain. However, in modern consciousness studies mind-brain theories tend to travel with a certain hidden agenda. The mind is identical to the brain as described by neuroscience text books. So far so good, except that when we read such a text book, there is nothing in it which either requires or could generate consciousness. We are presented with a closed information system from which consciousness is entirely missing. Incidentally an end chapter, which may be found in some more recent books, giving a round up of current theories of consciousness does not constitute an explanation of why consciousness is missing from the main text. The problem we have in conventional mind-brain identity theory is that the mind is claimed to be identical to a brain that, as described, has no requirement for consciousness and had no way of generating it. Elsewhere this chapter has a rather confused take on some other theories of consciousness. Curiously, the authors appear to conflate quantum consciousness with epiphenomenalism. The assumption appears to be that any quantum states in the brain must be by-products of processes based on classical physics, suggesting a rather strange take on physics, and this is odder still because epiphenomenonalists tend to indignantly reject the idea of any quantum involvement. Another curious idea is the conception of persistence through time as the factor underlying consciousness. Admittedly awareness or record of lifespan to date is usually part of the contents of human consciousness, but it is another thing to say that this produces consciousness. A non-conscious computer only needs a clock to record how long it has been in existence. It is also noticeable in this piece that in a fashion reminiscent of twentieth century thinking cognition is frequently equated to consciousness or the potential for consciousness, while emotion or evaluation of sensory input is hardly mentioned. Recent neuroscience, however points to a significant involvement of these latter factors. 6 JANUARY 2012 CONSCIOUSNESS AND EXECUTIVE FUNCTION The quest for animal consciousness Andrea Nani, Clare Eddy & Andrea Cavanna, Universities of Turin, Birmingham and UCL Journal of Cosmology, 2011, Vol. 14 Keywords: conscious sensory information, consciousness and executive function INTRODUCTION: The most interesting aspect of this paper is the reference to studies demonstrating that only sensory information that is reported as conscious in humans is able to activate brain regions dealing with executive functions. Studies of neural activity indicate an overlap between human and animal activity. Studies in many species suggest that some behaviours cannot be explained simply by stimulus and response. In humans there is a marked difference between the EEGs of conscious and unconscious subjects. Conscious activity is particularly associated with the approx. 20-70 Hz gamma synchrony. The distinctive EEGs as between waking states, and states regarded as unconscious in humans is also apparent in all mammals that have been studied in this respect. Conscious activity in humans correlates with specific interactions between the thalamus and the cortex, which are also found in animals. The thalamocortical system appeared mainly in mammals about 100 million years ago. Birds possess functionally comparable structures. The tendency for consciousness to be related to widespread activity in the brain is also found in animals performing functions that are correlated to consciousness in humans. Studies (Frackowiak, 2004) shows that in humans only sensory information that is reported as conscious activates the executive regions of the brain. The dorsolateral prefrontal is normally seen as the most important region of the brain in this respect. This implies that consciousness has an essential functional role in the human brain, and something similar is likely to arise in other mammals given their similar brains. Studies of animal behaviour produces instances of where they have to form simple executive plans, or have anticipated the likely future location of objects. 4 JANUARY 2012 CONSCIOUSNESS AS CROSSTALK MECHANISM Conscious states are a crosstalk mechanism for only a subset of brain processes Ezequiel Morsella & Tiffany Jantz In:- Consciousness and the Universe Keywords: Consciousness, orbitofrontal, intra-brain communication The authors accept the consensus view that conscious states represent only a subset of brain processing, and that the integration of sensory information and most cognitive processes are unconscious, . It is suggested that identification of processes that are unconscious can reveal those processes that involve consciousness by a process of elimination. The hypothesis here is that consciousness establishes intra-brain communication for a subset of brain processes. These brain processes are suggested to the control of voluntary actions. This is designated as supramodular interaction theory (SIT).The authors specify what is not involved in SIT. It does not relate to complexity, feedback, memory or meaning. Instead their attention is focused on conscious conflicts such as holding breath, pain suppression, suppression of socially inappropriate behaviour, or a physically difficult process such as trying to look right when there is a bright flash to the left. It is suggested that consciousness is involved when two brain processes work towards different actions. Where there is just a single stream of processing leading to an action, such as withdrawing a hand from a hot stove, there is no requirement for consciousness. In situations of conflict, it is suggested that the impulses from different and conflicting streams of brain processing are held in the 'conscious field'. The authors describe the muscular system used for actions as a steering wheel that different parts of the brain try to control. Consciousness is viewed as the process by which conflicting parts of the brain communicate with one another. The authors accept that some process other than consciousness could in principle resolve these conflicts, but say that evolution has selected for consciousness to perform this function. The authors think that within the brain consciousness derives from a particular type of processing involving interaction between regions rather than depending on a particular region. Different outcomes result according to whether there is interregional activity or not. Unconscious processing involves smaller brain networks than conscious processing. Consciousness is related to the ventral stream which is not used for execution of action, but is involved in knowledge-based selection of actions. The authors are cautious in respect of the hypothesis that consciousness derives from the feedback loop between cortical and thalamic neurons, because we consciously experience smell, although in contrast to the other senses olfactory neurons go directly to the cortex, mainly the orbitofrontal and pyriform cortices rather than via the thalamus. However, the thalamus does subsequently receive inputs from the regions involved in olfactory processing. Recent studies are claimed to show that consciousness is only involved in perceptions preceding actions or the experience of the result of actions. This chapter also touches on suggestion going back to Penfield in the mid twentieth century that consciousness derives from the subcortical rather than the cortical regions of the brain. The authors criticise the rush to label consciousness as an epiphenomena without understanding much about it. This chapter seems to try to steer the consciousness debate towards the area of choice/preference or as described here the resolution of conflict, which accords with other studies correlating activity in evaluation/choice areas of the brain with subjective preferences or assessments. The suggestion that consciousness only arises in the communication of larger brain networks also accords with recent studies of the gamma synchrony. However, as the authors themselves remark there is no attempt to describe how subjectivity arises in a physical system, only how it functions. 22 DECEMBER 2011 PROTOPHENOMENA Protophenomena and their physical correlates Bruce MacLennan Journal of Cosmology, 2011, vol. 14 Keywords: consciousness, self, neurons MacLennan says that he is discussing phenomenal consciousness or subjective awareness, the hard problem raised by David Chalmers. This is approached through the concept of 'protophenomena' described as 'elementary units of embodied subjectivity'. MacLennan suggests that the apparent continuity of consciousness can be broken down into smaller units, and that these units may correlate with the response activity of single neurons, an idea which appears compatible with current neuroscience. The author argues that given that neurons do not vary between cortices, different sensory qualities are likely to derive from different neural connections. McLennan speculates as to the location of what he calls 'activity sites' that might support the suggested 'protophenomena' units. After some discussion, the author appears to favour a proposal by another researcher, Norman D. Cook. The suggestion here is that the openings of the cell membrane, as the action potential passing along the neuron, breaks the barrier between the 'cellular self' or neuronal self and the external world. This is suggested to lead to an increased correlation between the external and internal states of the neuron and an 'increase in the mutual information' between the interior and exterior of the neuron. There is a problem here with the special role given to the extracellular space. With the exception of some electromagnetic field theories of consciousness, which are not being proposed here, the extracellular space is given a relatively limited role in the brain's processing. The so-called opening of the cell is an opening to ions rather than anything more sweeping or mysterious, and it is not clear why such a common place physical fluctuation should suddenly be responsible for inducing consciousness. The theory speaks of the correlation between the internal and external areas, but if we crunch this down into what neuroscience actually describes, it is merely the fluctuation in electrical potential. The same applies to the vague reference to mutual exchange of information. The complex processing that might reasonably be thought to have some correlation with consciousness is within the neurons and between them in the form of neurotransmitters, with the extracellular mainly limited to assisting the fluctuation in potential across the cell membrane. In the fullness of time, it may transpire that this is too narrow a view, and that the extracellular area does play a larger role. But given that this is not at the moment the view of mainstream neuroscience, we need some developed argument from the author if this enlarged role for the extracellular region is to carry conviction. The process suggested here by the author is referred to as 'protocognition', which seems on reflection to be merely saying that action potentials lie at the basis of cognition, but not why this should involve or lead to consciousness. Further, the neuron is supposed to comprise a 'self' that becomes aware as a result of opening to its immediate exterior. But while recent studies do point to neurons that select for particular complex experiences such as recognising various people, faces or places, the concept of the 'self' does seem to be linked to more widespread prefrontal activity organising the distinction between the body and the external environment and its history as recorded in the long-term memory. Sensory inputs look to be selected for by individual neurons, but studies show that concentration on sensory inputs may in fact lead to reduced awareness of the self, which in turn correlates to lower activity in the prefrontal. 21 DECEMBER 2011 FLEXIBILITY OF PREFERENCES The flexibility of chemosensory preferences Geraldine Coppin & David Sander, University of Geneva In:- Neuroscience of Preference and Choice (2012) Keywords: preferences, choice, neural flexibility, choice, consciousness The authors study preferences relative to odours, flavours and tastes, arguing for some flexibility in preferences over and above genetically determined preferences. Satiety can arise with respect to a food stuff that is initially rated as pleasant. The activity of the orbitofrontal is related to the evaluation of smells and tastes. This brain region also relates to social and financial stimuli. Activity in the orbitofrontal diminishes in line with the experience of satiety for a particular food stuff, so the subjective pleasantness of food is modulated by how much has already been eaten. The study compared the brain processing of subjects attempting to maintain a healthy diet, with subjects who were not concerned with this. The decisions of both groups related to activity in the ventromedial cortex, but for those seeking a healthier diet decisions were also related to the executive area of the dorsolateral prefrontal, so brain processing as well as actual choices is different for the healthy eating group. Although the authors describe this without further comment, the additional intervention of the dorsolateral executive function does seem to conflict with the widely held stance that there is no element of freewill in these or any other type of choice. The behaviour of the amygdala also goes beyond a simple one-to-one response to external stimuli. In response to food stuffs there is greater activity in the amygdala when the subject is hungry, and there is also greater activity in relation to food that were liked by the subject and a reduction when there was satiety. 20 DECEMBER 2011 PREDICTING EMOTIONAL REACTIONS Predicting emotional reactions: Mechanisms, bias and choice Tali Sharot, UCL, London In:- Neuroscience of Preference and Choice – Eds:- Dolan, R. & Sharot, T. Keywords: preference, choice, emotion, consciousness, caudate nucleus, basal ganglia The author examines the extent to which choices of behaviour emerge from the emotional system. It is stressed that this does not necessarily refer to immediate emotions but also to anticipated emotions. The process of how emotions are anticipated is therefore argued to be important for the process of choice. The faculty of imagination is seen as being adaptive in this respect. It allows different future scenarios to be viewed, and the emotions generated by these can be used to choose between different courses of action. Brain structures imagining the future overlap with those structures involved in remembering the past. Thus patients with problems in recalling memory due to damage in the hippocampal and frontal regions also have difficulty in imagining future scenarios. It has even been suggested that imagination of future scenarios rather than recall of past events is the core adaptive reason for these brain systems. Imagination of future events appears to involve the medial temporal lobe, some frontal areas and the caudate nucleus in the basal ganglia. Increased activity in the caudate nucleus is associated with the anticipation of rewards, and where there is a choice of rewards, the greatest activity correlates with the reward eventually chosen. Activity in the caudate nucleus also correlates to the imagination of unpleasant or punishing outcomes. The caudate nucleus is also one of the main targets for dopamine, the neuromodulator most related to reward learning and reward seeking, and in the signalling of errors in predicting rewards. It is argued here to be related to subjective estimation of future reward in the case of imagined future scenarios. A large body of evidence is indicated to contradict the earlier idea that dopamine acted directly as a neurotransmitter of reward. It is instead argued to strengthen the link between an imagined stimuli and a pleasurable reaction. 19 DECEMBER 2011 NEUROBIOLOGY OF PREFERENCES Mkael Symmonds & Raymond Dolan, University College London In:- Neuroscience of Preference and Choice – Eds. – Raymond Dolan & Tali Sharot Keywords: neuroscience of preference/choice, consciousness, orbitofrontal, dopamine As far back as the 1960s neuroscience had demonstrated a clear correlation between laboratory rats pressing a lever apparently for pleasure and the electrical stimulation of subcortical dopamine structures. The dopamine system is ancient from an evolutionary point of view. It is shown that fruit flies can make choices that are supported by their dopamine system, without the need for a highly developed prefrontal cortex. Although preferences are seen to be rooted in biology, they also appear flexible and sometimes even inconsistent. However, there is also thought to be a sometimes unconscious default in favour of the status quo. This default requires enhanced neural activity to overcome it, and this is related to activity in the subthalamic nucleus. The orbitofrontal cortex appears to play an important role in representing the value of sensory inputs, but it does not act in isolation, having reciprocal connections with the parietal, cingulate and insula cortices and with subcortical areas such as the basal ganglia, all of which are involved in evaluation of sensory inputs. A distinction is made between 'wanting' and 'liking'. The latter is taken to refer to immediate sensory pleasure, while 'wanting' is related to longer-term anticipated rewards. The authors here suggest that 'liking' depends on an endogenous opiod system, while 'wanting' is related to the dopamine system. The authors also touch on the existence of 'exploratory behaviour' that goes beyond established preferences. This behaviour appears to derive from parts of the prefrontal. The authors think in terms of preferences being based on communication between a network of brain regions rather than any individual region. A study by Gottfried, O'Doherty & Dolan (2003) showed responses that were not directly related to the stimulus, but where activation decreased, when satiety with a particular sensory input occurred. This study involved activity in the orbitofrontal, the amygdala, the piriform cortex and the midbrain, but only particular sub-regions of the orbitofrontal and the amygdala decreased in response to satiety. Reductions in activity in line with satiety were also observed in the insula cortex and the striatum in the basal ganglia. Recordings in the orbitofrontal have shown a correlation between preferences and the activity of single neurons. Dopaminergic neurons located in the ventral tegmental and substantia nigra (SN) regions of the mid brain vary their firing in response to reward stimuli, but dopamine release does not always correlate to preference. One suggestion is that these areas monitor the relationship between predicted reward and reward obtained. There are specific dopaminergic projections to brain regions, particularly the striatum and areas of the prefrontal. Modulation of dopamine in the orbitofrontal and the striatum is related to decision taking. The orbitofrontal is particularly involved with the evaluation of stimuli where there has been a learning process, but the anterior cingulate also appears to be involved in the evaluation of actions. Dopamine depletion in both the ventral striatum area of the basal ganglia and the interior cingulate leads to reduced disposition to making physical efforts. Other neurotransmitters such as noradrenaline and serotonin are thought to be involved in risky decision taking. 18 DECEMBER 2011 SUBJECT DRIVEN COGNITIVE STATES Decoding subject-driven cognitive states with whole-brain connectivity patterns Shirer, W.R. et al, Stanford Cerebral Cortex, doi.10.193/cercor/bhr099 Keywords: consciousness, cognition, brain connectivity In this research 90 functional regions of interest were identified across the connectivity of the whole brain, involving a matrix of 3,960 cells. Subjects were performing simple functions such as remembering the events of the day. This meant brain processing was generated internally by the subject (subject-driven) rather than in response to external prompting. This type of processing is suggested to account for the greater part of conscious processing. By contrast most research has focused on discontinuous events rather than the more continuous processing that seems to be common in conscious processing. Out of the 3,960 cells studied, 187 were regions of interest for the resting brain, 147 for memory, 114 for music and 265 for the function of subtraction. In a task such as recalling the events of the day, connectivity in memory related regions is seen to be increased. Other tasks activate connectivity extending to the basal ganglia. The authors review cognitive processing as a reshuffling or shifting pattern of connectivity between a set of spatially distributed brain networks.17 DECEMBER 2011 QUANTUM BOUNDARY Researchers at Oxford University have produced quantum entanglement at room temperature between two diamonds each measuring three millimetres across. This experiment is pushing the quantum boundary in two directions, in terms of the size of things that can be entangled, now coming up to being visible to the naked eye, and in achieving this at room temperature. The earlier expectation was that the number of atoms in objects of this size, and the relatively high temperature would mean that quantum entanglement would be destroyed. The diamond experiment could be seen as supportive of the idea that quantum superposition never collapses, but is somehow fudged out in macroscopic objects. However, there may be another aspect to these findings. The researchers point out that their success in this project really comes from observing the diamonds over the very short timescale of 100 femtoseconds. (= 100 x 10^-13 seconds). This could be argued to tie in with the Penrose hypothesis that wave function collapse relates directly to the size of objects, with time to collapse being shorter and shorter as size increases. It also appears relevant to the recent discoveries in photosynthetic organisms, where quantum coherence over femtosecond timescales is seen to play a role in energy transfer within organisms. This might make it easier to conceive of quantum states playing a role within individual neurons over a femto or picosecond timescale rather than the more ambitious concept of quantum states being sustained over 25 ms across the whole of the brain-spanning global gamma synchrony.16 DECEMBER 2011 QUANTUM BIOLOGY PROSPECTS - 2012 Jim Al-Khalili, professor of physics at the University of Surrey writes that he expects quantum biology to 'really take off'' in 2012 following the discovering of quantum states in photosynthesis and other areas of biology. He hopes to organise an international workshop in the summer to discuss the state of and prospects for this field. 8 DECEMBER 2011 PRESSURE FOR MULTIVERSE ORTHODOXY The pressure is on to get multiverses and many world theories accepted as an orthodoxy. A popular science magazine claims that everything from cosmology to quantum mechanics and string theory points to multiple universes, and that this solves the fine tuning problem. But these claims should be examined with care. The inclusion of quantum mechanics presumably refers to the Everett many worlds hypothesis. This is an entirely different theory from the idea of multiverses formed at the beginning, and proposes instead the constant splitting of the modern universe into new universes. It was proposed well before the multiverse idea became popular. The claim that string theory supports the multiverse borders on spin. The equations of string theory may have 10^500 solutions. This would normally be taken to show that a theory could not be falsified and did not qualify as a scientific theory rather than allowing it to support another theory. Even the apparently more reasonable claim that a multiverse solves the fine tuning problem looks more shaky on examination. The inflationary phase that allows the generation of multiverses may require a low entropy which is even more improbable than the fine tuning that it solves. This in turn can be claimed to be solved by a chaotic inflaton field preceding the inflationary phase. However, this looks to require something lawlike to specify the behaviour of the inflation field. As usual with the beginning, we look to be stuck in an infinite regress. 6 DECEMBER 2011 SELF-ONLY CONSCIOUSNESS The Importance of what's missing Terrence Deacon, University of California Berkeley New Scientist, 26 November 2011 Keywords: Consciousness, the self, sensory cortex, frontal cortex The author acknowledges at the beginning of this article that despite two decades of intensive work in both neuroscience and consciousness studies, we do not appear to be any nearer to forming a scientific consensus on the nature of consciousness. He starts by discussing the constraints that emerge in physical forms. For example, as a snow crystal grows the positions for new additions to the crystal become more and more restricted. What is not present or not able to be present is seen as being as important as what is present. The author intends to relate this type of abstract rule to consciousness. This leads him to discuss molecular processes in relation to the constitution of 'the self'. These molecular processes tend to self-assemble and to reconstitute in the event of disruption, and thus become a self-sustaining process with an 'end' of maintaining themselves. This is suggested to bring with it a capacity for distinguishing self and non-self. This approach to the self may be interesting, but what is disappointing from the point of view of deriving a theory of consciousness is that it is effectively a resort to the oldest 'get out of jail free' card in consciousness studies. The author assumes without seeming to be aware of any need for even arguing the case that 'the self' is the same thing as consciousness. Now all that he needs to do is to explain or deconstruct the self, which has been done by many writers with less complex systems than the molecular basis suggested here. Self-only consciousness The initial argument against 'self-only' consciousness is that we are conscious of a lot of things other than the self. However, this introspective approach is now supported by recent studies. Rafael Malach of the Weizmann Institute carried out a study, in which he scanned the brains of subjects watching a film containing dramatic or emotional content. It was shown that the more engaging the film, the less activity there was in the frontal cortex, which is associated with the formation of the self. There was a similar finding in a study by Hasson et al (2004), which also scanned brain activation in subjects viewing a film. In general, the rear part of the brain, which is orientated towards the external environment, demonstrated widespread activation. In contrast, the front of the brain and some areas of the rear brain showed little activation. These less active areas are referred to as the 'intrinsic system' that deals with introspection, and the 'first person' or 'self' aspects of the mind. This network shows a major reduction in activation at the times that perception is most absorbing for the subject. In Malach's study, the gamma synchrony, which is the best known correlate of consciousness, was seen to have widespread activity in the sensory cortex and the limbic areas rather than the frontal regions associated with planning and execution. Malach suggests that the role of the frontal areas is not to create perceptual consciousness, but to deliberate on the significance of the sensory experience. He thinks that when subjects are sufficiently absorbed by their sensory perceptions, as with the film used in his study, they 'lose themselves', in the sense of not having any introspection about what they are perceiving. It is also argued here that consciousness arises of its own accord in the sensory cortex, without being dependent on the frontal cortices supposed to be related to the sense of self. This argument looks to undermine attempts to dismiss the problem of consciousness by conflating it with the self, and then after that deconstructing the self. 29 NOVEMBER 2011 IMPLICATIONS OF ANAESTHESIA based on, Linda Geddes, New Scientist, 26 November 2011 Keywords: Consciousness, anaesthetics, gamma synchrony, single neurons This article highlights an important change in the understanding of anaesthetics during the last part of the twentieth century. Previously it had been thought that anaesthetics worked by disrupting the lipid membranes of neurons. Later experiments showed that anaesthetics can bind to receptor proteins. The widely used anaesthetic, Propofol, binds to receptors for the inhibitory neurotransmitter, GABA. Studies by the anaesthetist, George Mashour, show in particular that feedback from the frontal to the sensory cortex is inhibited in anaesthesia. Modern studies of the influence of anaesthetics on the brain have implicated a large number of brain regions suggesting that there is no single site or region that is switched off by anaesthetics. The author links this to Bernard Baars' global workspace theory in which sensory information is first processed locally and unconsciously before becoming conscious when broadcast to the wider brain. Baars' theory as originally proposed appeared to lack any real basis in neuroscience, but seemed to 'get lucky' when neuroscience identified the workings of the local and global gamma synchronies. In respect of anaesthesia, studies show a loss of synchrony between different regions of the cortex. Under Propofol, small regions of the brain of the brain are still responsive to stimuli, but the spread of activity to other regions seen in normal brain processing is lacking. This article also raises the old question as to whether consciousness is an 'all-or-nothing' property, or as favoured here by both the writer and Mashour, more like a dimmer switch. In essence, there are three stages to anaesthesia. In the first stage, the patient is consciousness, but experiences a state similar to being drunk. At the secon |
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