Volition and the readiness potential

Gilberto Gomes

Volition and the Readiness Potential

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

http://ingentaconnect.com/journals/browse/imp/jcs

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.

 

 

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