Archive 9

Archive 9:

6 January - 2 February 2011

27 JANUARY 2011
PENROSE MISQUOTED
Roger Penrose must be one of the misquoted scientists in history, often by writers who rush to refute him without having bothered to read what he proposed. The 'New Scientist' is a useful guide to what's going on in the scientific world, and it hasn't attempted to refute Penrose, but it has still failed to quote his ideas correctly. An article on quantum theory in the January 22 issue claims that Penrose proposes that the outcome of experiments is the result of gravitational interactions. What is not made clear is that gravitational interactions only come into play if quanta are isolated from the environment for a sufficient time. This could happen naturally or in an experiment. For the rest he thinks that there is a wave function collapse as a result of environmental interaction/experiments with a random selection of properties such as position resulting from this.

25 JANUARY 2011
CONSCIOUS INFLUENCES ON PAIN AREAS IN THE BRAIN
Price et al carried out an experiment in which there was an increased level of pain. In the first session the patients received no treatment. In a second session using the same heightened level of pain, the patients were told that they were receiving a treatment that substantially reduced pain in some patients. The patients reported a substantially lower level of pain, although the treatment was a placebo. This was to be expected in line with long medical experience. What was more interesting was that brain scanning showed reduced activity in brain areas related to pain in the thalamus, somatosensory cortex and the insula. This appears to demonstrate the influence of spoken words and presumably conscious intake on processing within the brain.

19 JANUARY 2011
MORE ON THE VENTRAL AND DORSAL STREAMS
Pierre Jacob and Frederique de Vignemont discuss Goodale and Milner's the concept of the 'two visual systems' model in a recent chapter in 'Perception, Acion and Consciousness (2010) (under Neuroscience8). This concept involves a functional distinction between vision used for perception, involving the separation of an object from its background, and vision used for action. In this proposal, the ventral stream is related to perception and is conscious, while the dorsal stream is related to action, and is unconscious.

Goodale and Milner's research relates particularly to a patient known as D.F. who is impaired in the identification of the shape and size of objects, but who can reach and grasp objects accurately. The tests to establish this were manual rather than verbal, therefore the results cannot be accounted for by problems with language processing. This phenomenon is regarded by Goodale and Milner as being similar to blindsight, which is also usually related to the distinction between the ventral and the dorsal stream.

Other patients, who have damage to the dorsal stream, but not the ventral, can recognise objects but have difficulties in reaching to grasp them. This is argued to point to two independent methods for processing the same initial visual stimulus instantiated in the ventral and dorsal streams. The ventral stream projects from the primary visual cortex to the inferior temporal cortex, while the dorsal also projects from the primary visual area but to the superior parietal area. The ventral is concerned with perception, while the dorsal is concerned with spatial action. Further to this the ventral appears to be related to conscious processing and the dorsal to unconscious processing.

In reaching and grasping, as performed by the dorsal stream, the subject uses egocentric coordinates based on their own body for an action performed by the body. The ability of the patient D.F. to grasp objects is assumed to use egocentric coordinates based on her hands. Perceptual judgements are flexible in being able to use either egocentric coordinates or allocentric coordinates based on an object external from the body. Allocentric perception is about comparisons between external objects, and as such it is prone to visual illusions. New visual perceptions may also be linked to older perceptions stored in the memory. Perception handled by the ventral stream enlarges the subject's knowledge of their surroundings.

A counter argument to the two visual systems model has been that the distinction is not between perception and action but between allocentric and egocentric approaches. However, the authors argue that where the patient D.F. failed in certain tasks, it was because she was using the manual-dorsal information to attempt to perform a perceptual task. D.F. is viewed as being able to detect a target on the basis of egocentric coordinates based on her fingers, but her dorsal stream is not thought to be capable of providing spatial information that required an allocentric frame of reference.

One view of perception is that it allows a target to be discriminated from its background and from other potential targets. After this has been achieved vision-for-action can take over the control of actual movements. There is some argument as to whether patients with ventral stream damage are actually aware of the shape and size of objects, but are simply unable to report them. However, the authors argue that in cases where perceptual illusions might arise, there is no cognitive dissonance apparent between the ability to grasp an objection and some perception that might be at odds with what is grasped, meaning that there is in fact no conscious visual perception. However, the task of grasping by itself allowed the patient to gain an above chance level of locating the position of the object. Moreover a further experiment showed that the patient D.F. could actually only discriminate the width of the objection in question, but could not describe the overall shape. In conclusion, the authors consider it unlikely that the patient D.F. is visually aware of the shapes and features of the objects that she can grasp.

13 JANUARY 2011
VENTRAL AND DORSAL STREAMS
The neuroscientists, David Milner and Melvyn Goodale writing in 'Perception, Action and Consciousness' (under Neuroscience8) propose a model in which there are distinct paths for vision for perception and vision for action. This involves to pathways the ventral and the dorsal streams. The authors understand the distinct streams in terms of their output rather than their input. It is claimed that initial visual information is transformed in different ways for different purposes. The ventral stream is argued to turn inputs into representations of the characteristics of objects including their spatial position. Both conscious and unconscious perceptions are here thought to be processed in the ventral stream. The dorsal stream is seen as guiding bodily actions such as reaching and grasping objects. The ventral stream is seen as providing our subjective experience of the world, but not the basis for physical action. It is accepted that perception can influence action, in fact this is one of the things it evolved to do, but the connection is argued to be indirect and flexible, and to involve memory and planning.

The authors distinguish between movement and action. For them movement refers to the simple physical movement of an arm or a leg etc., while action involves planning and possibly more than one movement. It is interesting in this context that the Libet and similar experiments that are taken as an absolute refutation of the existence of freewill refer exclusively to single movements, and not to the planning of actions involving multiple movements. The authors argue that the ventral stream is only involved in the planning of actions to deal with goal-objects that have been perceived. The actual implementation of the action depends on the dorsal stream.

The authors refer to evidence for the importance of the dorsal stream in control of action such as the acts of reaching or grasping. Such actions are impaired in patients with damage to the dorsal stream. Furthermore patients who have damage to the ventral stream, so that they cannot identify object, but who do have damage to the dorsal stream, can reach and grasp the objects that they cannot identify. This is similar to the phenomenon of blindsight, which is also thought to result from the distinction between the ventral and the dorsal stream.

The ways in which subjects are prone to visual illusions is also argued to support this distinction between the ventral and the dorsal functions. In particular tests subjects misjudge the length of objects, but when they reach to grasp these objects they correctly estimate their lengths. The author's findings have proved controversial within neuroscience. One criticism has been that the distinction in D.F.'s behaviour has not been between ventral and dorsal processing but between tasks where viewing is performed from the point-of-view of the subject (egocentric) and where it is based on a separate reference point (allocentric). However, the authors argue that the test quoted in fact showed the subject D.F. using her dorsal functioning to report on her perceptual judgement.

The authors argue that perception and action evolved to perform separate tasks in different ways. Action or grasping requires an accurate estimate of the size of objects, whereas for perception it may be more useful to have an estimate of the relative size of more than one remote object, preserved in time to allow the recognition of objects and their relationships. A study by Aglioti et al (1. 1995) showed that a grip aperture in a disc was less subject to a standard illusion when it had to be grasped than when the object was merely viewed. A study by Biegstraaten et al (2. 2007) showed no reason to think that perceived size guided how we grasped an object.

The authors think that their model suggests that the dorsal-based vision for action works only in real time. A study on the patient D.F. by Goodale et al (3. 1994a) showed that while she could grasp correctly when the object was present, she could not remember the correct grasp soon after the object was removed, indicating that working memory was not functioning in this respect. The authors accept that there will not be complete immunity to visual illusion and some element of illusion could come through from the visual cortex prior to the division of the dorsal and the ventral stream. Particular types of illusion arise in the early cortex rather than the ventral stream.

It is also admitted that more unpractised actions may require cognitive involvement and therefore be less dependent on the dorsal stream, and require more perceptual involvement. Control appears to pass to the dorsal stream once the movement becomes more practised. A study by Gonzalez et al (4. 2006) showed that unfamiliar actions where subject to the effect of visual illusions in the same manner as visual perception, but in contrast to familiar actions. The authors argue that some studies that have suggested that grasping type are subject to illusions only reflect the fact that equipment involved in the experiment has rendered the action required unfamiliar, and therefore subject to illusion. The Gonzalez study also showed that the right hand was less prone to illusions, presumably because it is more practised in most subjects. In studies involving patients pointing at objects, the performance of those with ventral stream damage deteriorated when they had to remember a position. This is ascribed to reliance on the dorsal stream. In contrast a patient with damage to the dorsal stream showed improved performance when having to remember a position, because as time passed they relied more on the perceptual/ventral stream.

6 JANUARY 2011
FOURTEEN PROBLEMS IN THINKING ABOUT CONSCIOUSNESS
The New Year seems a good time to consider why it has proved so difficult for modern researchers to think about consciousness in a constructive way, and why although the taboo on the subject has been removed for more than 20 years we still seem to be stuck with an orthodoxy that lacks convincing explanatory power.

Below are detailed fourteen problems that seem to stymie consciousness studies:-

1.) Newtonian assumption: Much of consciousness studies makes the elementary error of assuming the thing that it sets out to prove. The assumption is that consciousness in the brain can be explained in terms of classical Newtonian physics as already understood one hundred a years ago. This can be argued to have led to much convoluted and unrewarding effort to try and shoehorn consciousness into macroscopic classical physics.

2.) Non-physical: A curious subscript to the Newtonian assumption is the frequent and confidently asserted claim that consciousness is 'non-physical'. A newcomer to consciousness studies might expect this claim to come from the dualist wing, but the theorists who advance this idea invariably subscribe to a universe which is purely physical. In their view, which I would not disagree with, knowledge or experience of the external world could only come from physical signals from that world and can only be registered by some physical process. In that consciousness provides representations of the external world, it must itself be physical in order to receive signals from the external physical world.

3.) Complexity: Some approaches attempt to leverage consciousness out of the complexity of the brain. This is a beguiling solution as it encourages a sloppy, non-specific idea that somehow or other the property of consciousness must be conjured from this mass of complexity. When this notion is questioned more closely it does not stand up that well, as it is difficult to find a specific place or process, where the non-conscious changes into the conscious by means of some classical physical process. A favourite candidate has been the repeated exchange of signals between different areas of the brain, such as between the thalamus and the cortex, or more abstractly thoughts about thoughts, which is essentially one lot of processing reacting to another lot of processing. The detail of this is electrochemical signals passing to and fro again and again, but it is not apparent how or where these non-conscious electrochemical signals would change into conscious ones. The idea that if one thing observes another, it will become conscious has no validity in terms of modern technology, where non-conscious machinery manages surveillance and reactivity very well without any hint of consciousness.

4.) Non-explanations: Other popular classical explanations are in a sense non-explanations. Functionalism has been the most popular mainstream version of consciousness in recent decades. This is the concept that wherever an information processing system comparable to the brain arises it will become consciousness regardless of whether its physical basis is in biological tissue, a silicon computer or something else. The trouble with this, although it is not often noticed in the mainstream literature, is that the proposal does not actually explain the process by which we move from non-conscious to conscious in either brains or computers. Epiphenomenonalism where consciousness is a usually non-efficacious by-product of brain processing is similarly a non-explanation since even if consciousness is a by-product, classical physics still lacks a way of generating or physically describing this by-product.

5.) Flat Earthism: This is essentially the argument that because in the past the way the world appeared to be in the end turned out to be better described by classical physics, it will only be a matter of time before research demonstrates that consciousness is part of classical physics. The problem here is the very success of classical physics and related areas of biochemistry that have told us everything that macroscopic classical physics can do or produce, and consciousness is not a property that is amongst these.

6.) Problem denial: Closely related to 'flat Earthism' are attempts at problem denial. In a classic example of this it is suggested that further research will show that consciousness does not really exist, in the same way that phlogiston that was used to explain fire in some seventeenth century theories was shown not to exist. The problem here is not so much improbability as a basic violation of logic. In the analogy here, consciousness is in the place of the fire which the seventeenth century scientists were trying to explain, not of phlogiston which was merely a means to that end. The equivalent of what their modern counterparts are trying to do is to say that there is no such thing as fire.

7.) Redefinition: A common line of attack is to redefine consciousness as some part of the contents of consciousness, explain that, and then move on quickly claiming to have explained consciousness. The favourite route here is to explain the self or self- consciousness, which is easily done in terms of memory and awareness of the boundaries of the body, and then claim to have explained consciousness. The problem here is that we aware of things other than the self and conscious observation continues even when the sense of self is lost.

8.) Qualia: In general consciousness studies is for ever veering away from the fact that what is really difficult to explain is the qualia or subjective conscious experiences, so much learning and effort is expended on areas that are at best peripheral to consciousness.

9.) Fundamental physics: The difficulties that classical physics has in explaining how consciousness arises are not hard to see. From this it would be expected that theorists would have turned to fundamental physics for an explanation. Classical physics functions on the basis of a limited set of rules as to what it can do or produce, and is powerless to explain things that do not fit into these rules. It is nowadays seen as a special case or subset of physics as a whole. The difference with fundamental physics is that it is possible to postulate things that are irreducible, that have no further explanation, or are given properties of the universe. Thus the electromagnetic, expressed in terms of the charge on particles such as the electron, has no further explanation, it is just a primitive fact of the universe. Given the failure of classical physics in this area, consciousness looks capable of falling into a similar category.

We find instead that fundamental or quantum theories of consciousness studies are a ridiculed fringe area. The reasons for this look to be deeply rooted in the century-long failure of the educational system and popular scientific thinking to get to grips with quantum theory. Instead the approach has been to retain the Newtonian billiard ball picture of the universe, and confine quantum to a box for specialists. Even those who continue into higher physics education have been encouraged to regard quantum theory as a system of calculations without physical implications. In recent decades this has to some extent boomeranged on the establishment by allowing the suggestion that something outright dualist or fantastic is going on in quantum physics. However, an association with sometimes ungrounded ideas has allowed the mainstream to pour ridicule on quantum consciousness, bandying around phrases such as 'pixie dust' or 'hallucinating pseudoscientists'. Here it is also frequently considered sufficient to rely on the single knock out punch argument, rather than a proper consideration of theories. A classic example is the claim sometimes seen that quantum features cannot be relevant because they could not operate at the neuronal level, thus not bothering to register that most quantum proposal are at much smaller levels. Further to this, on the internet, attacks based on exceptionally superficial knowledge of quantum theories have become a handy way of demonstrating a writer's supposedly superior scientific education or knowledge. P. 10.) Levels: An idea has crept into consciousness studies, particularly in respect to quantum consciousness that some consciousness proposals can be ruled out because they do not operate at the right 'level', the idea presumably being that quantum features are at the wrong level for larger scale brain processing. This seems misleading on two counts, firstly that quantum features may act upwards from intra neuronal processing via neural assemblies and the gamma synchrony, and secondly relatively small number of individual molecules via receptors can act on an overall brain state.

11.) Science-lite consciousness studies: Related to the virtual taboo surrounding fundamental physics is the surprising relative neglect of science as a whole and neuroscience in particular in the greater part of consciousness studies. This has an historical basis in that so far as consciousness was discussed at all, it was seen as being part of the realm of philosophy or psychology rather than disciplines such as physics or neuroscience. Papers and even whole books that discuss consciousness proceed with barely a reference to the nitty-gritty of the brain, or to recent important advances in neuroscience and biophysics. In the background is either an assumption that everything important about the brain had been discovered by the middle of the last century, or functionalism where biology is not important and the computer properties of the system are supposed to already be understood. Evolution is an area of science that is frequently discussed at length in consciousness studies, but at the same time there is a tendency to play fast and loose with the basic discipline of the theory, which is that nature selects for features that are adaptive, which might suggest that there must be something adaptive about consciousness.

12.) Computers and brains: Another area where conventional consciousness studies has not got to grips with the increasing problems is the question of computers and brains. In the mid-twentieth century computers tended to be seen as a more or less analogous to brains, and it was confidently predicted that in the quite short-term computers could be linked to machines so as to produce autonomous robots. Inspite of much and continuing spin to the contrary in popular science writing, the history of artificial intelligence has demonstrated a failure to find an algorithm for how the brain achieves perception. This of itself demonstrates that the brain does something that existing computers cannot.

13.) The emotional brain: Another problem of consciousness studies, at least until fairly recently, was the insistence on ignoring the role of emotions. Science fiction in the last century enjoyed the idea of aliens and robots whose superior performance derived in part from a lack of emotions that could supposedly get in the way of reasoning. More recently, it has been understood that brains malfunction badly when the influence of the emotional system is disrupted. Moreover, the emotional rather than the rational preference of one thing or course of action for another, rooted as it is in qualia, is the one thing that an external observer might use to decide that a particular entity was conscious. Despite this, even amongst those neuroscientists who are doing excellent work on the emotional brain, there is a tendency to assume that consciousness has to be exclusively related to reasoning, although no basis for this assumption is given.

14.) Bullying/appeals to authority/outsourcing/trivia: Several additional flaws can be seen as common in modern consciousness studies. Notable is a type of bullying where the reader is constantly told that opposition to the writer's idea are ridiculous, until there is a willingness to accept whatever the writer proposes. This has been quite a successful tactic in expressing the current orthodoxy. Appeals to authority are also quite popular, such as a statement in a peer-reviewed paper that quantum consciousness must be wrong because it conflicted with existing ideas. Related to this is a tendency for neuroscientists and artificial intelligence theorists to outsource discussions of consciousness to authoritative third parties, usually philosophers intent on conserving a Newtonian world view. This does not involve an integration of philosophical ideas with data, but rather a wholesale downloading of the established mainstream position without any reference to the data. Further to this, fixation with trivia has been a problem related to the freewill debate. The discovery by Libet that trivial actions such as flexing a finger were not controlled by conscious thought has placed a virtual block on the discussion of agency in more deliberative or strategic activities.