Conscious intention and brain activity

Conscious Intention & Brain Activity

Peter Haggard, Institute of Cognitive Neuroscience, University College London
 & Benjamin Libet

Journal of Consciousness Studies, 8, No. 11, 2001, pp. 47-63

Haggard advances the idea that conscious awareness of intention is linked to the choice of a specific action, rather than the initiation of an action process. Libet’s experiments had suggested that readiness potentials for action happened before the consciousness of volition to act. The experiments appeared to confirm a pre-existing neuroscientific bias in favour of the idea that consciousness had little or no role to play. His theory seemed to show that unconscious preparations for action preceded awareness of the wish to act. He did however try to save freewill by positing a conscious veto that could prevent the action being performed. This qualification of his initial finding proved a good deal less popular with the neuroscientific establsihment.
Haggard’s first substantial criticism of the Libet experiment is that the fact that the readiness potential came before the conscious awareness is necessary but not sufficient to establish a causal relationship. Other neural events might also impact consciousness. Haggard distinguishes between the initial readiness potential and the lateral readiness potential (LRP), which comes when the subject has decided which hand to use in the Libet experiment. The LRP was found to have a closer correlation with perceived moment of conscious volition than the original readiness potential (RP) highlighted by the Libet experiment. This suggested that the conscious intention was related to specific rather than a general preparation for action. Haggard asks why it is might be that consciousness was associated with the selection of a specific action. Computational work relative to motor control has established that movement selection is the most difficult problem in action, because there are an infinite number of possible movements that could achieve a particular end, and there is no unique solution. Haggard suggests a relation between the necessary information processing for movement selection and conscious information processing. He suggests that his proposition could be tested by experiment, by matching experience of intention to movement selecting processing in the brain. In terms of the Libet veto, Haggard connects this to the decision as to whether a specific action selected at the point of the readiness potential is in fact the best possible action, or a suitable action at all.
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One Response

  1. I recently got the idea that the memory is a filing archive where copies of every considered action was lodged just prior to a conscious decision to act.

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