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Freewill 1

Papers, articles and books relevant to freewill

Freewill 1-7 includes summaries and reviews of papers by Libet, Searle, Dennett, Jeffrey Schwarz, Sharon Begley, Henry Stapp, David Hodgeson, Kathleen Vos, Baer, Roy Baumeister, Albert Bandura, John Bargh, Chris Frith, Merlin Donald and Paula Droege.

1.) Mind Time - Benjamin Libet - Account of his life's work in consciousness experiments

2.) The Volitional Brain - Libet et al

3.) Do we have freewill - Benjamin Libet

4.) Functional anatomy of volition - Spence & Frith - Looks to have an evolutionary advantage from freewill, while still arguing against its reality

5.) On volition - Ingvar, D. - Discusses physical changes during willed actions

6.) Primate basal ganglia & voluntary behaviour - Schultz, W. - Discuuses neural activity underlying willed actions

7.) Volition & the readiness potential - Gomes, G. - Freewill discussed from the basis of deterministic assumptions

8.) Volition & Physical Laws - Jean Burns - Looks for consciouness to be based on fundamental physical properties

1.)

Mind Time

Benjamin Libet

In his introductory chapter, Libet admits that his views on subjective phenomena have altered somewhat since he was a young scientist. He says that he started with a full belief in determinsitic materialism, but has come round to the view that the subjective cannot be derived from neuronal function. He now instead highlights the distinction between being clever in the sense of solving complex problems and being conscious. In contrast to many 20th century philosophers and scientists, he stresses the importance of introspection. He thinks that any evidence that does not involve introspection cannot be taken as evidence of consciousness.

Large amounts of brain damage can occur without loss of consciousness, but on the other hand small amounts of damage to the brain stem or the intralaminar nuclei of the thalamus can cause loss of consciousness. Penfield, who performed many of the original experiments in the mapping of the brain, proposed that consciousness was located in these structures. However, Libet argues that although the brain stem is necessary for consciousness, it is not sufficient for consciouness as experieinced in large brains. For instance the functioning of the heart is necessary for consciousness in the brain, but it is certainly not sufficient for it. Penfield's experiments showed that while much of the cortex produced no conscious reponses, there were conscious reponses from the primary sensory somatic areas, the visual cortex and the temporal lobe. The other areas of the brain are assummed to mediate neural activity unconsciously.

Libet's own experiments showed that the brain needed about half a second of activation before anything could come into consciousness. Nevertheless, subjects feel as if we are aware of a stimuli almost immediately. In Libet's experiments, he placed electrodes on the somatosensory cortex, the area of the cortex that receives sensory input from the body. Sensory input from the skin ascends to the brain by several different spinal pathways. Repetitive pulses had to continue for about 0.5 seconds to come into consciousness, which is surprisingly long for any neural function. In the experiments there was no conscious sensation, if the train of pulses persisted for less than 0.5 seconds, even if a shorter pulse was of high intensity.

The 0.5 second delay for sensations to come into consciousness was nothing to do with the unusual process of directly stimulating the cortex. The nerves that carry sensory information from most of the body are carried up the spine and terminate on nuclei in the medulla oblongata in the lower part of the brain. From here nerve fibres run to the thalamus and from there to the somatosensory cortex. This is known as the specific projection pathway.

Libet discusses the electrical response of the cortex to a single stimulus to the skin that is itself shorter than 0.5 seconds. A single pulse gives rise to a sequence of cortical electrical changes called evoked potentials (EP), known to represent nerve cell reponses. A primary EP arises in the relevant part of the somatosensory cortex within tens of milliseconds of the original skin stimulus. This can produce further neural activity lasting for more than 0.5 seconds, so that the short impulse to the skin can get into consciousness. These so-called late responses are necessary for achieving consciousness. Although normally involved with conscious processing, the EP is neither necessary nor sufficient to consciousness. It is shown to be inessential, because direct stimuli to the cortex by electrodes can produce conscious experience without producing an EP.

Libet discusses the question of 'backward masking' of stimuli, a phenomenon that was already known before his experiments. Experiments show that if a small pulse of light is followed by a stronger pulse within 100ms or more, the subject may not be aware of the first pulse. This can also apply to stimuli to the skin. However, if the delay is greater than 500ms, the subject will be aware of the first pulse. Libet argues that with the brain needing 500ms of activation for a stimuli to come into consciousness, another pulse during this period may interfere with the completion of the activation. Where the first stimulus was applied to the skin but the second stronger pulse directly to the cortex, the first stimulus was masked even for a delay of between 200 and 500ms. This experiment was seen as giving further support to the notion that 500ms of neural activation is needed for anything to come into consciousness. It was also found that on occassions a second impulse enhanced rather than masked the perception of the first impulse. This was seen as significant, as there had been some suggestions that it was the memory of the first impulse that was disrupted by the second impulse.

Libet stresses that it is possible to detect and respond to unconscious stimuli in a much shorter period of time than 500ms, and that it is only access to consciousness that requires such a long period. Therefore consciousness itself is argued to be a separate property from the mental events of detecting and responding. Libet does not think the access to consciousness is some sort of energetic build up, otherwise a single very strong pulse might go straight into consciousness. Rather the duration of activation is itself a code for access to consciousness.

Libet discusses the relationship between the 500ms access to consciousness and short-term or working memory. Dennett has suggested the 500ms is the time it takes to produce a short-term memory trace. There are two possible arguments here, either that the production of the memory trace is itself the code for consciousness, or that consciousness is not significantly delayed, but the memory trace needed to report consciousness does not emerge for 500ms.

Libet, however, argues against both these possibilities. He points out that patients who have lost the ability to form new memories retain normal consciousness. There is also trace conditioning, where one stimulus is associated with another, but there is a gap between the two. Amnesiacs, who have damage in the hippocampal region, cannot acquire trace conditioning. However, these patients are conscious suggesting that the ability to lay down memories and access to consciousness are separate functions.

Libet discusses a debate he had with Dennett at a conference in London. Dennett argued that the consciousness delay did not refer to consciousness, but the time needed to lay down a memory and then report it. Libet argues that delayed input of a second stimulus interfers with the consciousness of the first input suggesting that it is not merely a matter of memory recall, but Dennett suggested that the second input disrupted the laying down of memory for the first. Libet now counters that if there is a third input, consciousness of the second stimulus does not emerge, but the first stimulus re-emerges, which would not be the case if its emergence into consciousness was dependent on a memory trace erased by the second stimulus.

This still leaves the question of what the primary evoked potential actually does given that it is shown to be neither necessary nor sufficient for consciousness. In practise, it appears to be a timing marker, allowing the actual entry into conscious to feel as if it happened at the time of the stimulus. If, as in the case of some stroke patients, EPs no longer occur in certain parts of the somatosensory cortex, then stimuli to the relevant parts of the body will be expereinced as taking 500ms to come into consciousness. The loss of the EP deletes the ability to refer consciousness backward in time to the actual time of the stimulus.

Further experiments by Libet showed that readiness potentials arise in the brain 550ms before a voluntary act, but awareness of the intention to make the conscious act appears only 150-200ms before. So the supposedly voluntary act is initiated before the subject becomes aware of the wish to do it. P This experiment looked at free volntary acts performed without time restriction. The prescribed action was a sudden flexing of the wrist. The subjects were asked not to pre-plan when they would flex their wrists, but some insisted on doing this, so Libet gives results for planned and pre-planned action. With the planned responses the RP was 800-1000ms before the act. With no pre-planning the RP was narrowed down to 550ms, although Libet suggests the activity in the brain could start before there is a recordable RP. The awareness of the wish to act averaged 200ms in both the planned and unplanned instances. This awareness was in turn found to precede actual muscle activation by 150-200ms. Thus the will to act appears 350ms after the unplanned RP emerges.

Libet proposes the idea of a conscious veto. He points out that vetoing of an urge to act is a common experience. Tests on planned acts showed that the veto could be achieved in the last 100-200ms.

Libet attempts to discuss whether more complicated acts than a wrist flexion are governed in the same way. He points out that RPs have been found to precede more complex acts, such as starting to speak or write. This rather evades the point, since the act of beginning itself is an essentially simple mechanical act, such as moving a key on a key board, as distinct from the deliberative or strategic process of, for instance, deciding to write an article.

Libet gets round really discussing this by splitting off the deliberation about an act from the actual final action, and arguing that one can deliberate indefinitely and not act. This doesn’t really answer the question of what happens when we deliberate and do act, and the drive behind this is associated with the deliberation rather than a trivial mechanical act. P In the latter part of his book, Libet goes on to propose ‘a conscious mental field theory.’ He puts the familiar question as to how subjective experience can arise from nerve cells in the brain. He admits that finding the correlates of consciousness does not solve the problem, of how physical structures produce subjective sensation.

Libet finds himself forced back on the emergent property concept, but admits that it is a property that it is not directly observable or measurable. He likens this emergence of consciousness to the emergence of mass etc. from the fundamental particles, but apparently misses the point that neurons and other brain structures are far from fundamental. However, he regards conscious subjective experience as a fundamental property in nature. The binding problem is also supposed to be accounted for by the proposed emergent mental sphere, with no single cell or group of cells likely to be the site of consciouness. Consciousness is claimed to be globally distributed but only some cells are involved.

Libet wants to view conscious subjective experience as a field. Such a field would provide communication with the cerebral cortex outside of the neural pathways. The field would mediate between the physical activities of nerve cells and the emergent subjective experience. It solves the binding problem. The field would have the ability to effect or alter some neuronal functions. The field would not be in any category of physical fields or describable by any existing physical theory. In fact, it is detectable only in terms of subjective experience, and would not be amenable to observation in the way that all physical fields are.

It is, however, suggested to be a testable feature of brain function, although the proposed test, which is to create conscious experience in isolated bits of brain tissue, does not make it clear how consciousness would be communicated to the experimenters, and is in any case debatable because of the observed lack of ‘self starting’ qualities in actual isolated biological tissue. P The theory seems to suffer from all the disadvantages of dualism, without the advantage of not have to justify itself in terms of complex brain mechanisms.

2.)

The Volitional Brain: Editor’s Introduction

Benjamin Libet, Anthony Freeman and Keith Sutherland

Journal of Consciousness Studies, 6, Nos 8-9, (1999)

In Libet’s experiment the subjects were asked to wait for the urge to make a previously specified wrist movement. This was intended to bring the largest possible element of freewill into the experiment. The subjects should want to act and feel they had control over the action. The article points out that their are many human actions in which the feeling of control is lacking. Involuntary actions related to conditions such as Parkinsonism and alien hand syndrome (pre-motor damage) are felt not to be under the patient’s control, and are made without or even against the patient’s will.The performance of acts perceived as voluntary is preceded by electrical changes known as readiness potentials (Kornhuber & Deecke, 1965) (1). Electrical activity was shown to start up to one second before the relevant action. The 1965 experiment did not allow the subjects a free choice in their timing of the required action. In his 1982 experiment, Libet removed this constraint, and the subjects could choose their own timing. On average the readiness potential in these tests occurred 550ms before the action was performed. However, Libet also wanted to know how long before the action, the subjects were conscious of the wish or decision to make a movement. His experiment showed that on average subjects were aware of the wish to act only 200ms before the action compared to a readiness potential of 550ms before the action. The timing of the conscious wish was the same even where the subjects had pre-planned to act at roughly that time. Libet calculated an average error of -50ms in the subjects judgement of time, so he reckoned the wish to act was only 150ms before the action, and 400ms after the readiness potential. Out of this time, Libet advised that one should take another 50ms for the signal to go from the motor cortex to the point of action, leaving only 100ms for any involvement of consciousness in the process.Libet thought that the conscious brain had the potential to stop the forthcoming action during this period, even though it was not responsible for the original initiation of the movement. Experimentally, Libet was able to demonstrate the vetoing of pre-planned actions. He also points out that in conditions such as Tourettes, where patients make unwilled movements or speech, these are not preceded by an RP. Similarly a quick reaction to an unexpected stimuli is not preceded by an RP. In acts which can be voluntary, but have become routine and automatic, the amplitude of the RP is indicated to be minimal.

Our sense of freewill depends on a balance between reliability and flexibility. Without reliability outcomes become arbitrary, and without flexibility outcomes are predetermined. The deterministic viewpoint is based on classical physics. A minority of physicists think that the debate on freewill and consciousness is taking place against the backdrop of an old fashioned view of science, and that full acceptance of quantum theory would have a dramatic impact on the free will debate. This position is complicated by the lack of agreement on the implications of quantum theory.

Mainstream science’s believe in determinism and rejection of freewill is beginning to have consequences in public life, beyond academic debate. Scientists such as Blakemore and Crick have demanded a radical recasting of the legal system to recognise the non-existence of freewill. This at least frankly recognises the consequences of their believes, by contrast with commentators such as Dennett and Pinker, who try to argue for determinism while continuing to draw some social benefits from freewill.

There is a also a bleak warning that while more knowledge may derive from progress in brain imaging, this is likely to be interpreted in line with the dominant paradigm, which simply assumes that freewill is an illusion.

3.)

Do we have freewill?

Benjamin Libet

The article concentrates on Libet’s own experiments showing that unconscious electrical activity in the brain preceded voluntary actions by up to 400ms. This discovery has been widely seized on, although not be Libet himself, as a proof that freewill does not exist and thus as a confirmation of the deterministic paradigm of mainstream neuroscience. The main flaw with these experiments and the conclusions drawn from them is that they focus on the trivial. In Libet’s own experiment the subjects had agreed to flex their wrist at some point, and therefore only the timing of the action constituted a free choice. The point about this is that we all know that we perform a lot of voluntary actions on automatic pilot. We go into a room, and then find we don’t know what we went in for, or we find ourselves walking or driving down the road to the commuter station, when we need to take another road that we only use once or twice a year. However, we would not normally take the view that we did have the freedom to choose not to go to the commuter station at any given point. This would look to apply even more to the large scale decisions in life, such as what university to go to, what career to follow or who to marry. It is hard to demonstrate that the readiness potential for a trivial movement such as flexing the wrist has much relevance to such decisions, although these are just the sort of decisions that one would associate with free will.

Libet does address this question in this article, in order to support the idea that it is satisfactory to base our view of free will on such trivial acts, although his arguments do not appear convincing. He points out that simple systems often inform as to the functioning of more complex ones. That measuring the charge of one electron led to knowing the charge of all electrons. However, the example does not provide a very good analogy for the temporal extension and complexity of the type of decisions that we most associate with goodwill. Libet also points out that readiness potentials have been found to precede more sophisticated activities such as beginning to speak or write. However, actual the action of speaking or writing is not in principle very different from flexing a wrist. The relevant thing for a discussion of freewill is the content of the speech or writing and possible earlier consideration of whether this content should be communicated. Libet accepts that deliberation on whether to do something can continue over an indefinite period, but stresses of the actual action which will be preceded by an RP. However, many people might associate their freewill with the process of deliberation, and not the trivial action of getting up from their chair to implement their decision.

Experiments by Libet and in an earlier period by Kornhuber & Deecke demonstrated that that actions that are perceived as voluntary are preceded by an electrical change in the brain known as a readiness potential (RP). This potential begins on average 550ms before an unplanned act. However, it takes human subjects another 350-400ms to become conscious of the intention to act, leaving only a maximum of 200ms before the actual motor act. The brain process for a conscious act therefore starts before the subject is consciously awareness of it.

In this article, Libet considers the possibility that is favoured by some commentators, to the effect that the conscious veto is itself preceded by an unconscious RP. Libet argues that the veto is a different class of sensation from being aware of an intention to do something, in that it is a control function. He also refers to his own earlier experiments that demonstrate a 400ms difference between a signal reaching the brain, and the subject becoming consciously aware of this (Libet et al 1979) (2). Similarly, the later experiments showed a 400ms delay between the onset of the RP and consciousness of the intention to act. (Libet et al, 1983 and Libet 1985) (3&4). The volitional process is seen as coming into play at this point. Libet proposes that this volitional process is not confined to just the urge to act but could embrace aspects of the brain that might implement a veto. Libet sees the function of free will not as starting a voluntary action, but as deciding whether it should go ahead. The impulses for voluntary action are seen as something that appear spontaneously from the unconscious functioning of the brain.

4.)

Sean Spence & Chris Frith

Towards a Functional Anatomy of Volition

Journal of Consciousness Studies, 6, Nos. 8-9, 1999, pp. 11-29

The article attempts to examine the brain anatomy related to volition. It is indicated that a number of brain regions are involved in those actions that are felt by the subject to be conscious and willed. The dorsolateral prefrontal cortex (DLPFC) is particularly important in this respect. The normal function of choosing or feeling that one chooses one action rather than another is compromised in the event of dysfunction in the DLPFC. The experience of freewill is seen by the authors as linked to the activity of the DLPFC and associated brain areas.

The authors are more cautious than others in their claims for what brain imaging of subjects performing simple repetitive tasks can tell us. Elsewhere we discuss what seem to be rather unconvincing arguments advanced by Libet for seeing these studies as conclusive, while Gilberto Gomes does not discuss the problem, simply assuming that this approach is adequate. Spence and Frith, however, admit that the tests do not bear much resemblance to actions perceived as free in real life.

The article points out the importance of the distinction between the front and rear of the brain. The rear lobes comprising occipital, parietal and temporal are involved in analysing incoming data, while the frontal, comprising about a third of the brain is involved with response to this data. The premotor and motor areas produce actual actions by the body. In front of these, the prefrontal regions are responsible for initiating actions based on the data in the rear lobes. The prefrontal regions project to the premotor cortex. The speech centres are also located in the prefrontal.

The anterior cingulate, located in the prefrontal, is involved in paying attention to and selecting information for action, and is connected to the premotor area that programmes forthcoming motor acts seemingly including speech. The anterior cingulate is also concerned with emotion and pain. Two other areas of the prefrontal, the orbito-frontal region and the ventral prefrontal are now thought to be possibly involved in modulation of actions relative to rewards or social context. This area of the brain suffered damage in the famous case of Phineas Gage, and it is thought to have been responsible for an adverse change in his personality. It has also been suggested that deficits in this area are related to psychopathy.

The DLPFC is part of a loop that involves thalamic nuclei and the basal ganglia. Damage to this loop can lead to problems with the executive function (Masterman & Cummings, 1997) (5). Damage to the basal ganglia, as in Parkinson’s disease can also harm the executive function.

The DLPFC is involved in working memory, where data is used within consciousness. Damage to this area is known to result in lack of spontaneous activity, repetitive behaviour, stereotyped responses to the environment and various inappropriate responses. There is a serious loss of the apparent freewill seen in normal humans with the patient becoming effectively dominated by their environment. Studies of patients with this type of damage show disturbances in the initiation of actions (Petrides & Milner 1982) (1). The authors suggest that what is happening is a loss of the inhibitory control of the other brain areas that is normally exerted by these areas of the prefrontal.

Studies of normal subjects show DLPFC activation during exercises involving generation of words and also finger movements. Studies allowed the authors to suggest that the left DLPFC played a role in generating novel movements and in selecting responses. There was an increase in DLPFC activity, when actions were being chosen or manipulated. In contrast, patients with depression or schizophrenia show a reduction in activity in the DLFPC. So the evidence points to the involvement of this area in spontaneous action. It is suggested that this brain region formulates goals, while the specific motor commands needed are delegated to the premotor area. (Passingham 1993) (2). This theory is supported by studies of animal brains showing activity in the DLPFC before activity in the premotor. (Goldman-Rakic et al, 1992) (3). It is suggested that the DLPFC selects from a rear brain output, consisting of a range of possible behaviours. In this hypothesis, it is the job of the DLPFC to select the one particular most appropriate behaviour and to inhibit the other behaviours (Goldman-Rakic, 1997) (4). Support for this notion comes from the fact that patients with DLPFC damage are unable to inhibit inappropriate behaviour.

Passingham (1997) (6) has contrasted activity in the DLPFC and the anterior cingulate on the hand to the premotor and basal ganglia on the other. The prefrontal areas are active in paying attention, making conscious decisions and also when movements are simply imagined. (Ingvar & Philipson 1977). (7). By way of contrast, these areas are inactive during routine tasks, while posterior and sub-cortical areas of the brain remain active during these routine tasks. This is taken to suggest that the prefrontal areas modify the behaviour of the other areas, when non-routine tasks are involved. These findings, with respect to the inhibitory or modifying functions of parts of the prefrontal, would seem to lend support to the Libet veto idea of conscious behaviour being able to modify actions initiated by unconscious brain activity.

Damage to any part of the brain loop linking pre-frontal, thalamus and basal ganglia leads to disorders, but these vary according to where the damage occurs. Parkinsons, where the damage is in the basal ganglia, produces difficulties in achieving movement, or an inability to overcome inhibition of movement, while other disorders may result in abnormal movements due to lack of inhibitions.

The DLPFC receives its largest input from the parietal lobe, which integrates information related to vision, touch, balance, spatial coordinates, memories of movements and also contributes to the direction of attention. A circuit involving the frontal and parietal lobes is vital to the execution of movements. The basal ganglia and supplementary motor area are also seen as faciltating movement, with DLPFC probably making the choice of movement. The authors note that even the very simple movements needed to scan experiments require complex neuronal activity spread over a wide area of the brain.

The article discusses the situation of patients who do not feel their actions to be self-determined. They discuss ‘alien hand syndrome’ where the patient’s hand or arms moves without the conscious involvement of the patient. Feinberg et al (1992) (8) interprets this as exploratory actions by the hand that emanate from the parietal, and would normally be inhibited and suppressed by the prefrontal areas. Some schizophrenic behaviour is seen in a similar light. Patients feel that their actions are not under their own control but that of some other agent. Frith (1992) (9) hypothesises that the problem derives from the patient’s lack of internal representation of the will to act, leading to a failure to suppress inappropriate acts. Scans of patients with alein control delusions have shown over activity in the parietal and other areas, activities which might have been suppressed by the prefrontal if it had had a representation of the planned action.

The authors conclude by saying that particular patterns of brain activity are related to the free will process of deciding what to do and when. The cingulate, premotor cortex, basal ganglia and parietal are also involved in these processes, but when actions are routine, they can perform tasks without the prefrontal areas. The parietal is thought to produce representations of intended actions, while the DLPFC keeps track of these, and selects one when action is necessary.

The article ends with a mention of freewill. The authors seem to side step the problem, by electing to discuss the evolutionary advantages of having the experience of freewill. Here they lack conviction. They suggest that the experience of choice is necessary for the distinction between ourselves and the external world. It is not apparent why this should be so, since any reasonably sophisticated monitoring device should be able to achieve this without any call for subjectivity or qualia. The authors also appear to touch on what is normally called theory of mind, the double guessing of the likely feelings and decision taking of other people or possibly animals. However, it still throws no light on what it is that produce these feelings, even if it could be shown that an algorithm could give a reasonable estaimates of what sort of feelings might arise.

Although the article sidesteps a discussion of freewill or consciousness, it nevertheless provides useful background relative to many of the discussions in this area. The location of much of the perception of consciousness and freewill in the prefrontal runs contrary to much of the spirit of Daniel Dennett’s thesis in ‘Consciousness Explained’. At the same time, the view that the prefrontal has a role in inhibiting unnecessary or inappropriate movement or speech is similar to Libet’s concept of a veto on actions arising from unconscious brain activity. It is worth remembering that the authors and those they quote draw on experimental evidence in contrast to Dennett and also some of Libet’s critics.

5.)

On Volition

David H. Ingvar

Journal of Consciousness Studies, 6, Nos 8-9 (1999) pp. 1-10

The article discusses studies of actual and imagined willed acts. These studies suggest that such acts are planned in the frontal and prefrontal cortex as programmes for motor, verbal, cognitive and other acts. Brain scanning shows that prefrontal activity is different for actual and imagined activities. In psychiatric illnesses, reductions in the resting activity of the prefrontal have been recorded. The relationship between will and prefrontal activity is compatible with the idea that the frontal and prefrontal cortex are involved in programming motor and speech behaviour and thinking.

The article defines will as the experience that one can generate objectives for future actions or thinking. This done, the will is further used to achieve these actions. Pure perception, including many qualia are, however, non-volitional. The article defines three steps to a willed act. Step one is the awareness of the need to obtain a particular objective, which is often related to sensory inflow with an emotional colouring. There may be an inner representation of the objective.

Brain scanning studies by Deecke & Lang (1996) (1 & 2) have reported that readiness potentials may build up seconds before a willed finger movement. This is at variance with Libet (1992) where the potential began only 550ms before the willed movement. The article suggests that the formulation of the objective may involve active suppression of thoughts that interfere with the objective. This inhibition of disruptive thoughts may emanate from the prefrontal and from the cingulate gyrus, Fuster (1989 & 1995) (3 & 4), Frith et al (1991) (5), Posner and Raichle (1994) (6).

Willed objectives range from simple motor acts to long term and complex activities. In the latter cases, objectives may be retained over a period of years. The article views them as a type of memory, which may be altered over the course of years.

Studies show that mental activity such as reasoning are accompanied by a moderate increase in blood flow, particularly in the frontal and prefrontal areas. The blood flow increased in relation to the difficulty of the mental problems posed. These studies also showed the differences between actual and imagined actions.

Studies demonstrate that willed acts cause a reduction of activity in some brain regions. The article suggests that this may represent a suppression of alternative plans. Some studies show a relationship between volition and the dorsolateral prefrontal cortex, an area known to be related to working memory.

Eccles (1982) (7) suggests that the supplementary motor area (SMA) might be particularly involved in the production of willed motor acts. This is suggested as an interface area between the prefrontal and motor action and behaviour. Deecke et al also think that willed movements may emanate from this area.

6.)

Wolfram Schultz

The Primate Basal Ganglia and the Voluntary Control of Behaviour

Journal of Consciousness Studies, 6, Nos 8-9 (1999)

The article discusses experiments to determine the neural processes underlying goal-directed behaviour. It was found that single neurons in the striatum became active a few seconds before movements made in the absence of external stimuli. There was also activation in the closely connected supplementary motor area. These activations may be related to intentional states directed at bodily movements. In relation to animals responding to the expectation of reward, it is suggested that these activations might relate to a prediction as to the likely outcome of behaviour before it is actually enacted.

The functions of the basal ganglia have been defined by the deficits that arise when there is brain damage or degeneration in these areas, notably in the case of Parkinson’s disease. This suggests that this area is related to voluntary limb and eye movement, particularly spontaneous movements. The basal ganglia are closely connected to the frontal lobe, and this is taken to suggest that the basal ganglia are involved in cognition directed at the organisation of behaviour. Experiments with primates has revealed activity in the basal ganglia related to the preparation of movement (Apicella et al 1992) (1). Other studies have shown that parts of the basal ganglia are involved in motivational behaviour, such as learning in relation to rewards.

Experiments with monkeys have been used to studying movements initiated without any external stimuli. In one study, a monkey moved its arm in order to obtain a food reward. The neurons activated in this process were different from those activated when the arm was moved in response to an external stimulus. The area of the striatum appears to be active in between an urge to move and the actual movement. There is also pre-movement activity in the frontal cortex, notably the supplementary motor and pre-supplementary motor areas, the supplementary eye field, and premotor cortex, which all direct to the anterior striatum. Activity here, that is related to preparation for movement and rewards is taken to show that the striatal neurons access information about both the environment and the subject’s own actions.

This is seen by the author as providing the ‘aboutness’ or intentionality that is a feature of consciousness. They are not directly driven by events, but precede them, and concern forthcoming events. These beliefs, fears desires and intentions all have the property of intentionality. They are about particular objects, events or actions. Mental states with intentionality directed at goals are described as intentions. The striatum and frontal cortex are active preceding self-initiated movements, but are not acting on the basis of any external signal. In the case of a monkey seeking a food reward, it is suggested that the monkey has a desire for the food at the beginning of the experiment, and an intention of performing so as to obtain the food.

References:-

(1) Apicella et al (1992) Neural activity in monkey striatum related to expectation of predictable environmental events Journal of Neurophysiology, 68, pp. 945-60

Dickinson A Motivational control of goal directed action Animal Learning and Behaviour, 22, pp. 1-18

Libet, B et al (1983) Timing of conscious intention to act in relation in relation to onset of cerebral activities Brain, 106, pp. 623-642

Romeo, R & Schultz W (1987) Neuronal activity preceding self-initiated movements Experimental Brain Research, 91, pp. 396-407

Romeo, R & Schultz W (1992) Role of primate basal ganglia and frontal cortex in the internal generation of movements Experimental Brain Research , 91, pp. 396-407

Schlag, J. (1987) Evidence for a supplementary eye field Journal of Neurophysiology, 57, pp. 179-200

7.)

Gilberto Gomes

Volition and the Readiness Potential

Journal of Consciousness Studies, 6 Nos 8-9, pp. 59-76

Gomes appears to discuss the whole question of free will, from the basic assumption of a deterministic world, qualified by some macroscopic impact from the quantum level. As the latter is random, it is also deemed irrelevant for freewill. He assumes that what he calls the naturalistic view of the physical world means that the mind can only be properly looked at from the third person point of view. This is despite our lack of a theory of consciousness and the many unresolved problems in physics. It comes dangerously close to assuming what you set out to prove.

The article discusses the experiments of Kornhuber & Deecke (1965) (1) and Libet (1983-93) (2-5) relative to consciousness. It points out that Libet’s results indicated that the conscious intention to act happened after the onset of the readiness potential, but before the actual command that determined the movement of the muscle. He also found that a conscious decision could veto the action. Libet's view was that conscious acts started unconsciously, but could be controlled or vetoed by consciousness. Free will does not initiate but can control. Gomes says that he agrees with some of Libet’s propositions, namely that actions begin unconsciously and that they can be stopped.

Gomes gives both a first and third person definition of a conscious act. From the first person point of view it is an action that the subject feels they have determined. From the third person point of view, it is defined as an act that looks as though the person doing it has the feeling that it was a conscious decision. In either case, there is an implication that the person concerned had a choice about what they did.

In discussing choice Gomes touches on the question of quantum involvement, and like much of the mainstream literature tries to bat it away quickly as something unworthy of serious discussion. He admits that a random quantum event can initiate a causal chain that ends up being detectable at the macroscopic level. Like others, he points out that randomness is no more like the perception of free will than is determinism.

Gomes goes onto to discuss the experience of schizophrenic patients, who feel that their acts are not the result of their conscious decision, but are controlled by someone else. This impression can, however, be removed by the use of drugs. Gomes feels that this means that impression of voluntary acts is itself dependent on chemical events in the brain. However, it could just as well be argued, that when the brain does not detect its own agency it substitutes another false agency. This is consistent with the way in which the brain interprets, sometimes wrongly, the raw data that it receives from the outside world.

Gomes tackles the difficult question of what happens to morality and personal responsibility, if we accept that our actions are deterministic. He seeks to get himself out of this with a somewhat convoluted bit of reasoning. He takes the case of a person, who knowing that their actions are deterministic, decides that they should take no account of right or wrong. This situation is rejected as unrealistic as the very word 'should' in 'should take no account of right and wrong' is seen as meaningless in a determinstic world. However, he does not, as would seem necessary, discuss the difference or otherwise in brain processes between someone who thought they had decided to ignore right and wrong and a control who still thought they were taking it into account.

Gomes says ‘All we need is to suppose that there is, in human beings, a decision system that can represent actions and action sequences before their performance, that can select among them, and the output of which is not fully determined by its input, by also by its internal state, by representations of aims to be achieved, by internal criteria that affect its activity (moral and personal values, and also by a certain degree of randomness.’

This is all perfectly logical. Most theories accept that the brain can represent actions and their possible consequences. Post-behavioursim, most would accept that output is not solely determined by input. Pre-existing targets for activity may be adaptive. Similarly moral values may derive from earlier conditioning and/or from evolutionary selection in favour of organisms that to some degree cooperated with one another, or even assist one another. The whole thing hinges on some mechanism that selects amongst the possible courses of action. Even this does not present a problem. Since this is a deterministic model, selection or decision taking will be the product of an algorithm.

However, one problem remains. Consciousness has been left out or left unexplained. There is absolutely no requirement for consciousness in the process as described. Gomes seems to assume, but does not actually state that the ‘select’ command in this process is where consciousness comes in. But as this is a deterministic model, the select process must be performed by an algorithm, which cannot involve freewill, and has absolutely no requirement for consciousness.

The most common way round this has been to dismiss freewill and consciousness as illusions, thus creating formidable problems in terms of a physical process or thing (consciousness) that has no impact on the physical world around it, and which in a physical description of the brain must demand energy, without giving anything adaptive in return. Further to this there is a problem of how one could have an illusion without being conscious in the first place.

Gomes side steps this problem by trying to preserve a kind of facade of freewill, thus running with the freewill hare, while hunting with the deterministic pack. Free will is not then an illusion. Instead, it is something to do with the distinction between input from the external world and the brain. But here Gomes drags in the ‘self’ that favourite soft target of the reductionists. It doesn’t matter how often it is pointed out that the self is merely part of the contents of consciousness, the reductionists continue to confuse self and consciousness. Self is most often and reasonably deconstructed into the distinction between the body and the rest of the world, but the narrative history of brain and body as stored in and retrievable from the long term memory.

However, Gomes apparently ignores the body, but implicitly adopts a wider definition of self in other respects, including everything that he as listed in terms of representations of actions, aims and moral values. This is a bit of a jump. Firstly, some of this might be unconscious. Some of our objectives and some of our moral values or assumptions would appear to be below the conscious level. Furthermore, it is questionable whether representations of future actions can be regarded as part of the self. This looks more like a probability for the future development of the external world on which our actions will impact.

Whether or not we buy the Gomes view of the self, Gomes tries to make his trick, by saying that his form of self is free to select a decision about the external world, but that the self which is just the brain system is deterministic. He has his cake and eats it! But this is an argument with mirrors. If actions are selected by the self and the self is determinstic the amount of freedom in the system equals zero.

After this unpromising start, Gomes moves on to discuss the hard science. Gomes starts by mentioning the Kornhuber & Deecke experiment of 1965, which detected that voluntary movements were detected by cortical negative potentials, known as readiness potentials. These began between 400 and 4,000ms before the action was performed, but on average they fell into a range of 1,000 and 1,500ms before the action. A later series of experiments gave a lower average of 750ms but with some results above 1500ms. Kornhuber and Deecke commented that such an early readiness potential meant that the RP could not relate directly to the motor command, something must come in between. This conclusion may have been controversial given that behaviorism was still influential in the 1960s.

From the late 1970s onwards Libet performed experiments, where they tried to make the action tested as free as possible. The experiments quoted here averaged 577ms in one case and only 240ms in another. More typically an average of 550ms was quoted. The common factor is that they were all much shorter than the 1965 experiment. Despite this shortening, Libet also discovered that subjects only became conscious of the intention to act up to 400ms after the RP. On this basis, Libet concluded that voluntary acts were not spontaneously initiated. However, he estimated that there was an average 100ms between awareness of the intention to act and the start of an irrevocable command in the motor cortex. He thought that this period allowed consciousness/free will an opportunity to veto the intended action.

Gomes points out that there can be an ambiguity in the use of the word ‘intention’. It can refer to a mental event directly relating to a voluntary act, as in the Libet experiments. The other meaning is an intention to perform an action in the future, which can be viewed as a representation of an unperformed action. It can also refer to the intention to achieve the result of such an action, in which case it contains a representation of that result. Such an action can only be actually performed as a result of another decision, whether conscious or unconcious, at some point in the future.

At this point, Gomes, like Libet, seems to deliberately deny what most people might regard as the main function of any freewill that does exist. Gomes arbitrarily decides that deliberation about future actions doesn’t count. Only the final motor act counts. So if an individual spends a whole year deciding whether or not to go to a university, that doesn’t count, but the final act of getting out of their chair to go to the university is the only thing that counts. This seems nothing short of perverse, when we compare it to the ways people actually organise their lives, and raises suspicions of a metaphysical agends aimed at doing away with freewill. Nevertheless, it is reasonable to, as Gomes does, distinguish between three stages, the intention to act in the future, the intention to act now, or at least within the next 100ms, and the irrevocable motor decision.

Gomes discusses the Libet experiment where subjects aborted pre-planned actions 100-200ms before the planned time. This study was aimed at testing Libet’s proposed veto. The study showed the normal onset for the RP, but a falling off from 200ms before the planned time, which is in contrast to the experience when the action is carried out. Libet’s interpretation was that the subject could abort the action between becoming conscious of it and the onset of the irrevocable motor command. Gomes stresses that in Libet’s model it is only the decision not to carry out the action that may be experienced as a discrete event. Libet indicates that his experiments show that an action which has been initiated by an RP can be aborted after it has emerged into consciousness. Gomes points out that the decision to abort could be initiated by an unconscious process, just like the original RP. Libet and Gomes both admit that there is no experimental evidence on either side here. Gomes claims that the lack of specific evidence against a conscious control function is the extent of Libet’s argument.

However, this is not really the case, in that Libet argues that the veto is a different type of action, because of the involvement of consciousness, and because conscious control or inhibition is a different type of process from unconscious initiation. Moreover, Gomes does not take account of studies made during the 1990s suggesting that the dorsolateral prefrontal cortex, which is known to be active when conscious choices are being made, was also responsible for inhibiting and suppressing a possible range of other actions deriving from unconscious areas of the brain, especially when these were socially inappropriate. These include studies by Fuster (1989 & 1995), Frith et al (1991), Goldman-Rakic (1992 & 1997), while studies of alien hand syndrome by Feinberg et al (1992) and of schizophrenia by Frith (1992) suggests that these conditions involve unconscious impulses that would normally be suppressed by the dorsolateral prefrontal.

Gomes in fact becomes somewhat convoluted in trying to get rid of the idea of a veto. He admits that everyone has the experience of deciding not to an action they were close to doing. However, he argues that almost doing something is the same as not doing it, and that rather than thinking of a veto, one should simply think of the act not being done. This is a very strange line of reasoning since the whole previous line of thinking has been based on the early onset of readiness potentials. Unless he is arguing that they have a tendency to randomly peter out, these potentials would seemed to need some action from the brain to prevent them developing into actual motor acts.

8.)

Volition and Physical Laws

Jean Burns

Journal of Consciousness Studies, 6, No. 10, 1999, pp. 27-47

The author starts by pointing out that the presently known physical laws provide only determinism in classical physics and randomness within quantum physics neither of which can be a basis for freewill or volition. Burns suggests that if such a thing as volition does exist it only acts under certain conditions in the brain, and has only a limited effect, although the indirect effect may be magnified by a subjects subsequent actions.

Burns discusses the idea of emergent phenomena. It is frequently suggested that consciousness is an emergent property of the brain. Burns points out that combinations of particles and systems can lead to the emergence of new structures that have different characteristics from the component parts. She takes the example of a proton and electron combining to from a hydrogen atom which has quite different characteristics from the free particles, but are nonetheless determined by known laws of physics. The fact that the emergent properties are determined by known laws of physics means that this is termed ‘ordinary emergence.’

This is supposed to be distinct from ‘radical emergence’ where the emergent properties are not determined by the known laws of physics. Burns discusses Chalmers arguments relative to emergence. He says that if something is to be explained in terms of physics, it must be possible to trace it all the way back to the basic concepts and laws. Alwyn Scott criticised this position saying there were emergent properties such as the equations describing the ionic currents along the neuron membrane. He claims that these are incompatible with the physical law, because they are not time reversible. However, Burns argues that this only puts them in the same class as thermodynamics, where the non-reversibility is usually thought to be a result of involvement with the environment. Burns takes this to mean that there is no physical property, which can be completely unlike the physical laws and yet be derived from them.

Burns argues that if consciousness is physical, it must involve radical emergence, which would mean new elements in the physical law with specific relevance to consciousness. If consciousness arises from sufficiently complex matter, or in the case of functionalism from sufficiently complex calculations or computer activity, it is argued that this involves the radical emergence of a new physical law. Burns looks at the possibility that volition could arise from a choice between the possibilities inherent in quantum randomness. She argues that for this to be of any use, the randomness would have to have some ordering, and this too would require some new aspect to the physical law. The Penrose/Hameroff model looks to involve radical emergence since it requires the new physics of Penrose's objective reduction of the wave function.

Further to this, Burns looks at the possibility that volition is created by a new type of particle or field. She argues that this field would have to interact with electric charges, because brain processing involves electrical potentials. The interaction with this hypothetical new field or particle would add a new element to the electromagnetic field. This is argued to be impossible, because it would contradict known and experimentally tested data by which the electromagnetic field is shown to be unified with the weak nuclear field as the electroweak field at very high levels of energy. Libet has suggested a purely mental field called the conscious mental field (CMF). Burns argues that any physical effects from this field would require an alteration to the physical law.

Hagelin (1987) suggests that the sought after unified field, involving electromagnetism, gravity and the strong and the weak nuclear forces is the same as consciousness and that it acts via the collapse of the wave function. Burns argues that the unified field should comprise only the features of the four known fields and these do not include volition. Burns appears to favour a theory involving string theory. This involves hyperdimensional space. Sirag (1993 & 1996) has suggested that a hyperdimensional space that described all observables would be accompanied by another space called ‘reflection space’. The first space is suggested to describe all physical space, while reflection space corresponds to a universal mind, and consciousness would be the intersection of the two spaces. There are echoes of this in other theories. With Penrose consciousness is ultimately rooted in the fundamental spacetime geometry. His own ideas on spacetime involving spin networks and twistor theory are close to quantum loop gravity, which is a rival to string theory. The ideas of Jibu, Yasue and Vitiello also have similarities, appearing to ultimately invoke an interface between the brain and the external world, with consciousness as something acting between the two. The action of free will is suggested to be neither mathematically prescribed nor random, a concept which has apparent similarity to the non-computability advocated by Penrose.