Readiness potential (RP)
Refers to a scalp-recorded slow negative shift in electrical potential
generated by the brain
–> this begins up to a second or more before a voluntary motor act
When is an act regarded as voluntary ?
When
- it arises endogenously + not in direct response to an external stimulus
- there are no externally imposed restrictions that control the action
- one feels introspectively that one performs the act on ones own initiative
What were the participants of the Libet study instructed to do?
- Perform a prescribed motor act at some time after the start of each trial
- Pay close introspective attention to the onset of the urge to perform the act
BUT: should not plan the act but be “spontaneous”
What did the results of the Libet stud yield ?
The “physical” precedes the “mental”
–> the cerebral process precedes the conscious intention
What did Libet conclude based on the evidence ?
Voluntary acts can be initiated by unconscious cerebral processes before the conscious intention appears/occurs
–> so the brain decides to prepare the act before there is any reportable subjective awareness of the decision
Conscious volitional control
Operates to select + control volitional process
–> NOT to initiate it
Motor Potential
MP
Refers to an action potential that is elicited by the stimulation of a motor muscle
–> generated at about 50ms before the muscle EMG
THUS: there remains a fraction where conscious control could block the onset of MP
What did Soon try to investigate ?
They wanted to directly investigate
- which brain regions predetermine conscious intention
- the time at which brain regions start shaping the motor decision
Freely paced motor-decision task
Soon
Involved
- Fixating the centre of the green where a stream of letters was presented
- Choose to press one of 2 buttons + remembering the present letter
- After a response mapping screen appears, a second button should be pressed to choose the letter
–> a pattern-based decoder is used for analysis
Pattern-based decoders
Are trained to predict the specific outcome of a subjects motor intention
–> recognizes characteristic local brain patterns associated with each motor choice
Which brain regions encode the outcome during the execution phase ?
M1 and SMA
Which brain regions encode whether one is about to choose left or right prior to the conscious decision ?
(Soon)
- Frontopolar cortex
- -> first cortical stage at which the actual decision is made - Parietal cortex
- -> prenuceus is involved in the storage of the decision until it reaches awareness
What did the results of the Soon study yield?
The outcome of a decision can be encoded in the brain activity of the PFC + Parietal cortex up to 10s before it enters awareness
What is the basic argument of moral responsibility of our actions?
We cannot try be morally responsible for out actions because,
- Nothing can be cause sui ( because of itself)
2.
Responses against the basic argument
- Compatibilists
- -> one can be morally responsible even if determinism is true - Libertarian
- No-name option
Compatibilists
One is responsible as long as the actions are not caused by a certain se of constraints
e.g. OCD, threat
Name the problem associated with the compatibilists view.
It fails to amount for any sort of true moral responsibility
Libertarian view
Can be divided into 2 segments
- Incompatibilists
- -> belief that freedom + moral responsibility are incompatible with determinism - Libertarians
- -> we are free + morally responsible agents, therefore determinism is wrong
Name the problems associated withe the Libertarian view.
- How can falsity of determinism help?
- How can occurrence of partly random/indeterministic events contribute in any way to one’s being truly morally responsible for one’s actions/character?
- Moral responsibility depends on the falsity of determinism but determinism isn’t falsifiable
No name option
Accepts that one cannot ultimately be held responsible for ones personality no matter whether determinism is true or false
BUT: one can still truly be responsible for ones decisions + actions because ones self is independent of ones CPM
Name the problem associated with the no-name option view.
Whatever the self decides is because of the way one is.
–> thus the self must be responsible for the way it is in order for the objection to hold
Determinism
Refers to a doctrine that all events are ultimately determined by causes that are regarded as external to the will
e.g. human action
