Task 9 - Free will Flashcards
How does a voluntary act arise in relation to the cerebral process that mediate it?
READINESS POTENTIAL: Scalp recorded slow negative shifts in electrical potential generated in the Brain (SMA) and beginning up to a second or more before a voluntary motor act
- VOLUNTARY ACTS CAN BE INITIATED BY UNCONSCIOUS PROCESSES
- conscious control over actions remains possible
Type 1 and Type 2 RP
Self initiated acts were found to be preceded by RPs:
type 1 RP: om trials in which subjects reported PLANNING to act: ramp like RP with average onset at 1050 ms
Type 2 RP: uniquely associated with endogenous volitional process without any planning - onet at 550 ms before motor act
Definition of voluntary action and will
a) It arises endogenously, not in direct response to an external stimulus or cue
b) There are no externally imposed restrictions or compulsions that directly or immediately control subjects initiate and performance of act
c) Subjects feel introspectively that they are performing the act on their own initiative and that they are free to start or not to start the act as they wish
Study by Libet
Perform a prescribed motor act (flexing of finger) at some time (free to chose) while being scanned by EMG.
- Pay close introspective attention to the onset of the urge to perform the act
W- experience of first awareness of wanting to move
Timing; light split going around dock face - participants had to say on what number it was when the urge occurred
NOT PLAN THE ACT
W AND ONSET TIME OF ASSOCIATED CEREBRAL PROCESSES WERE COMPARED
Problems:
- Recording RP requires averaging many events, which may become boring and be performed in a stereotyped way - unsure that conscious control is used
- Since subjects are asked to act in a certain time interval, they may be under pressure to act
- Subjects were asked not to blink until just after each act - need to blink = external control factor
Solutions: external forces were minimized: each trial was a separate independent event determined after a delay by subjects readiness to proceed, no time limit, blinking allowed
RESULTS: RP onset time was consistently before W (urge to move). - 345 ms before
Problems: Validity of the criteria for W: it is impossible to determine the actual time of a subjective experience - there might be a discrepancy between actual and reported time of W
Solution: S-experiment
S-experiment
S-EXPERIMENT- Libet measured how precisely subjects could report W: He gave PP a skin-stimulus (S-value) knowing exactly when he gave it and PP reported when they felt it
RESULTS: subjects reported skin-sensations before they could actually be aware of it (skin sensations before W):
- this worked as an estimate for potential errors in reports of W:
Subjects probably also made the mistake of reporting S too early:
Transferred to W: subjects report too early to be aware of intention to move before actually being aware: Real W occurs at -150 ms
CRITICS: subjects may not judge the onset of an endogenous mental event the same way as a stimulus (external).
When subjects were asked to report when they started to actually move (may reflect awareness of initiation of cerebral Motor outflow) the problem did not happen
RP as an indicator of cerebral initiation
Is RP a valid indicator of the time when cerebral processes begin to produce an act?
- RP = volitional preparation to act = SMA
- RP = preprogramming processes that develop periodically without signifying a volitional function. Actions would depend on conscious activation of one of the preparing sequences
NOT SUPPORTED BY EVIDENCE:
a) RP didnt occur without movement so far
b) no conscious RP activating process has been found
- then actual motor performance would depend on conscious control, but what about reflexes?
CONCLUSION: Voluntary acts can be initiated by unconscious processes BEFORE conscious intention appear:
- conscious control may not initiate the act but select and control it: trigger final motor outcome vs. veto it
- both impulsive and deliberative acts are preceded by unconscious cerebral activity
Conscious volitional control
Motor potential (MP) is generated 50 ms before muscle EMG (0). There remains a period of -200 to -50 in which conscious control can block the onset of MP that would lead to an action
VETO: blocking of MP action by conscious control
- subjects report that during some trials an urge came up but was abolished before moving
- subjects were asked to develop an intention to act and veto it 100-200 ms before prearranged time: pre-event potential was recorded even though no act occured
ALTERNATIVE: a conscious trigger needed to impel unconsciously initiated cerebral processes to achieve a motor act
BOTH MODELS COULD BE AVAILABLE AT THE SAME TIME
Do the findings of Libet exclude the potential for free will?
No, because conscious control is needed in the end to block the onset (according to one theory) or facilitate the onset (according to the alternative)
Study: unconscious determinants of free decisions in the human brain
Directly investigates which brain regions predetermine conscious intentions
METHOD: freely paced motor decision task: fixate a screen where a stream of letters is presented. At one point chose to press one out of two buttons (left/right). One should remember the presented letter at the moment at which they acted. Response mapping screen occurred: 4 choices - one should indicate letter to map when they made a motor choice
PATTERN BASED- DECODERS: trained to predict the specific outcome of a subject’s motor intention by recognizing characteristic local brain patterns associated with each choice
- intentions were consciously formed 1000 ms before movement
RESULTS:
- outcome of subjects motor decision during execution: M1 and SMA
- Encoding subject choice to chose left or right button: prior to conscious decision!
a) frontpolar cortex (BA10): 7 sec before motor decision
b) Parietal cortex (precuneus) involved in storage of decision until it reaches awareness (shown by local spatial pattern of fMRI)
c) TIMING of decision: 5 s before- Pre-SMA& SMA
- in frontpolar and parietal cortex this was only possible just before the motor decision
CONCLUSION: SMA isn’t the ultimate decision stage where conscious intention is initiated:
PFC and parietal cortex encode up to 10 sec before it enters awareness
- double dissociation btw brain regions that shape specific outcome and those that determine timing
TENTATIVE CAUSAL MODEL OF INFO FLOW:
unconscious predictors of motor decision originate in FRONTOPOLAR –> PRECUNEUS –> SMA
Impossibility of moral responsibility
BASIC ARGUMENT: we cannot be truly responsible for our actions
- nothing can be the cause of itself
- in order to be truly responsible for ones actions, one would have to the the cause of himself
- therefore, nothing can be truly morally responsible
MAIN CLAIM: people cannot be expected to change themselves in such a way as to become morally responsible
1. one is the way one is (C-feature) as a result of heredity and experience
2. One cannot change the way one is later in life
3 the particular way in which one is moved to try to change oneself results from heredity and previous experience (S-procedure)
4. If changes are not due to those factors, they are due to indeterministic/random factors, for which one ist responsible either
TRUE MORAL RESPONSIBILITY:
situations of choice that occur regularly are the reason why we believe in true moral responsibility (self-conscious agent)
BUT according to the basic argument one cannot be
If one thinks about justice, the consequence of the basic argument is that no-one can ever be punished or rewarded
- punish someone for natural hair color is same as punish someone for their actions
How to reject the basic argument
To reject the basic argument, one must reject 2): To be truly responsible for what you do, one must be truly responsible for the way one is
Compatibilits (basic argument)
One can be tree and truly morally responsible even if determinism is true. One is truly responsible for what one does, just as long as one isn’t caused to act by any set of constraints
FALSE: it doesn’t require a person to be truly responsible for how one is - doesn’t reject the basic argument
- they think that punishment is appropriate in some setting and cannot do anything against counterarguments
Determinism
All events are ultimately determined by causes external to the will
Libertarian
we are all free and responsible moral agents and determinism is false. Decisions can only be explained in terms of free will:
- Indeterministic in its nature and outcome
- occurs in choice decision making
MORAL RESPONSIBILITY: behavior depends on genes and heredity, which she the way we are (C-features). S-procedure (trying to shape how we are) depend on C-features
This is the case independent of whether determinism is wrong or right
INDETERMINISTIC FACTORS:
Indeterministic factors cannot contribute to true moral responsibility in any way, because our actions are based on random influences, non-random influences (for which we are not responsible) and influences for which we are proximally responsible (but not ultimately)
PROBLEM: they say that true moral responsibility is only possible if indeterminism is true (determinism is wrong), but determinism is unfalsifiable
