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Topic: | Libet's puzzle |
Posted by: | Michael Lamport Commons |
Date/Time: | 2011/10/15 23:03:04 |
This may be helpful: Libet's puzzle The experiment Benjamin Libet's experiment1, 2 is carried out by fixing electroencephalogram (EEG) electrodes to a subject's scalp and an oscilloscope timer is set before the subject in sitting position. Then the experimenter instructs the subject to carry out some motor activity such as for example pressing a button. The subject would be asked to note the position of the dot in the timer when the subject was aware of the wish or urge to act and the act of pressing the button is also recorded electronically. Approximately it takes two hundred milliseconds between the first appearance of the conscious will to press the button and the act of pressing the button. The experimenter notes from EEG that the onset of cerebral activity (called readiness potential) starts approximately three hundred milliseconds before the subject was aware of the "conscious will" to press the button. This experimental finding has led some3, 4 to interpret that unconscious processes in the brain are true initiators of volitional acts and free will therefore plays no part in their initiation.? Free will and the brain responses JC Bose5, 6 talked of the power of directive control by will. He said, "There can be no doubt of the predispositions which can be conferred on the nerve by internal power of will in facilitating or inhibiting the nervous impulse. The effect of attention or expectation in enhancing perception is familiar as also is the power of suggestion". The brain may produce different responses at different speeds to the same stimuli. A visual input (stimuli) flows through thalamus, neocortex (the thinking or logical brain) and neocortex in turn routes the flow to amygdala (the emotional brain) for proper emotional response. However under a perceived potential threat the thalamus may direct the flow first to amygdala which is the trigger for flight or fight response. See for example a man walking on the road in dim light may just quickly jump perceiving a curled rope on the road as snake and will realize (due to logical processing of information by neocortex) later that his emotional response is misconceived and such a quick emotional response?may take over the brain in a millisecond which is termed as "amygdala high jack" by Daniel Goleman7, 8.? Discussion Going back to Libet's experiment and its interpretation, it appears that there is some confusion about "conscious will". This author had been arguing that will/ free will, the ability to take a decision or a series of decisions and consciousness, the ability of being/becoming aware of, are two different primary properties of the living systems along with "self programmability". It must be noted that the subject in Libet's experiment already had information input in his brain about the experiment as "suggested" by the experimenter. As a result of this suggestion and by the stimuli of the free will the subject decides the course of action which is indicated by the on set of the cerebral activity. The subject becomes aware (becomes conscious) of this activity with a lapse of approximately three hundred milliseconds and responds physically with a lapse of two hundred milliseconds. It does not matter if the subject is unaware of (not conscious of) the action/stimuli of free will as it happens from within the brain of the subject. In other words the onset of cerebral activity is not due to any external stimuli but it is internal that is from within the brain of the subject. After all the subject can't be aware or conscious of an action to be taken before free will decides what action is to be taken. Let us?see this analogy. We feed a computer with data say values of r and q of an equation?p= q*r and we expect the answer to be displayed. The computer can display the answer, the value of p on the monitor only after the computer has calculated and not before it. In Libet's experiment the programmer, the program, the computer and the monitor are one and the same, the "subject'. Probably the right way of interpreting Libet's experiment is that the power of directive control by will5,?precedes consciousness which is noted as the on set of cerebral activity. Thus the lapse of time between the action of will as noted by the on set of cerebral activity and the realization of the action of will by the subject only tells us about "consciousness lag". Also what we say as "unconscious brain" or "sub consciousness" are forms of "latent consciousness" which are not accessible to brain based consciousness. Opinion In the opinion of this author Libet's experiment is a clear proof of the existence free will, that free will and consciousness are not one and the same. Like neocortex and amygdala, free will and consciousness may respond to the same input with different speeds. The subject becomes aware of the decision of his free will with some time lag. If the onset of the cerebral activity in Libet's experiment is not due to free will then what caused it? Is it an effect without a cause? Note: From Microsoft Thesaurus, English (US): consciousness = awareness, realization, notice, perception, mindfulness, cognizance. Free will = autonomy, self determination, choice, liberty, freedom, independence, self rule, self government. References: [1] Benjamin Libet, http://en.wikipedia.org/wiki/Benjamin_Libet [2] Libet, B., Gleason, C. A., Wright, E. W., and Pearl, D. K. Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act. Brain, 106: 1983, 623-642. (cf) 1. Original article not seen. [3] Wegner D., The Illusion of Conscious Will. Cambridge, MA: MIT Press. 2002, (cf) 1. Original not seen. [4] http://www.susanblackmore.co.uk/Conferences/tucson96.html , (cf) 1. [5] Bose, JC, Unity of Life, Everyman's Science, Vol. XXXIX, No. 4, Oct.-Nov. 2004. 206 ¨C 223. [6]https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0Bwimo6n_JQscZWVmZjE3OWUtYTgzZi00MTA4LThmNDItNjQ4ZWI3MWEwZDI2&hl=en_US [7] Daniel Goleman, Emotional Intelligence, Bantam Books, New York, 1996, p. 18 [8] http://en.wikipedia.org/wiki/Amygdala_hijack [9] Sekhar, D.M.R, The paradox of life, Genopsych, Tanscience Transactions, Vol. 2, Scientific Publishers, Jodhpur, 2011, 1 -5. [10] Sekhar, DMR. The paradox of life: Life: a Defunct Scientific Theory? [Internet]. Version 20. Knol. 2011 Feb 13. Available from: http://knol.google.com/k/dmr-sekhar/the-paradox-of-life/3ecxygf1lxcn2/35 |