Week 5 - Conscious Will

Question 1

READINESS POTENTIAL

Answer 1

Brain activity which orepares the action

Question 2

Readiness potential complex

Answer 2

P1-n2 complex, positive. Name depends on polarity. Up negative and down is postive

Question 3

Kornhuber & Deecke were _____ who also believed in

Answer 3

materialists

free will, and were frustrated by behaviourism (which ignored the mind and only studied overt, stimulus-response relationships)

Question 4

KORNHUBER & DEECKE used eeg to

Answer 4

• They used EEG specifically to show that you could study mental activity, such as spontaneous, freely- willed actions, empirically and scientifically

Question 5

As far as Kornhuber & Deecke were concerned, the readiness potential proved that

Answer 5

willed actions have an underlying

basis in brain activity, in an ordinary materialistic way

Question 6

LIBET’S HYPOTHESIS

Answer 6

• said they didnt measure will per se.

- wanted to see when the will will happen

Question 7

3 D IFFERENT SERIES

Answer 7

• W-series: participants reported the time of their conscious awareness of wanting to perform a movement
• M-series: participants reported the time of their conscious awareness of having actually moved
• S-series: participants reported the time of an externally-applied skin stimulus

Question 8

2 DIFFERENT CLOCK MEASURES

Answer 8

• Absolute (A) mode: participants reported the clock time at the moment of conscious awareness

• Order (O) mode: participants reported if the clock’s stopping point was earlier or later than the point where they recalled becoming consciously aware
(Similar results fo both)

Question 9

TYPE I AND TYPE II MOVEMENTS

Answer 9

• Type I movements: pre-planned movements, where the participant recalled planning the movement prior to executing it
• Type II movements: spontaneous movements, where the participant did not recall planning the movement, and the movement happened spontaneously

Question 10

READINESS POTENTIAL MEASUREMENTS

Answer 10

• Readiness potential, main negative shift (RPmn): the time when the RP diverges from 0µV, marked by visual inspection by the researcher
• Readiness potential, 90% area under the curve (RP 90%): the time when the last 90% of the area under the RP curve begins

Question 11

Results:

• the W measire happened
• the readiness potential (rp 90%) begins on

Answer 11

• The W measure (the report of the conscious will to move) happens about 200ms before the actual movement begins
(Accounting for the bias revealed by the S-series reduces it to 160m)

• The readiness potential (RP 90%) begins on average 530ms before the movement for Type II movements, and 780ms before the movement for Type I movements
• Therefore, the readiness potential precedes the conscious experience of will by ~300ms
• Therefore, our conscious will cannot be the cause of the readiness potential which prepares the movement; the brain does this unconsciously

Question 12

Libets conclusions

Answer 12

• Libet considers this result as significantly constraining the role of consciousness in our behaviour
• Consciousness only happens later, after the movement plan is already on the verge of being executed
• experience of will might be caused by the readiness potential reaching a threshold, or by some other process

Question 13

Conscious will (W) happens after our brain prepares our action, but it still precedes the action; therefore, we may be able to
perform

Answer 13

a “conscious veto” of what our brain has prepared for us