 | Term | Definition |
| |
event related potential |
erp |
| |
readiness potention |
rp - gradual buildup of activity prior to voluntary action - will to act |
| |
jahanshahi et al (1995) |
internally-generated movements: early, strong rp. externally triggest movements: minimal rp |
| |
supplementary motor |
probable source of rp. medial wall, in front of the motor cortex |
| |
libet (1983) |
chronometric method. voluntary action: brain preparation, conscious experience. when do we perceive intetions - if conscious will is the cause of our actions, then conscious intention should precede rp onset - not true. rp precedes conscious thought by 200ms |
| |
wegner (2003) |
no real conscious experience of will, but a retrospective invention to explain why our body moves, and retroinserted into a stream of consciousness |
| |
fried et al (1991) |
stimulation of sma - urge to move right arm on low stimulation, movement of arm on higher current. |
| |
brass & haggard (2007) |
inhibiting actions. prepare voluntary keypress actions, on freely chosen trials, cancel action at last minute. judge time of intention to move, whether moved or not. event related fmri locked to conscious intention.there is a veto process in the brain, does not mean it is conscious. there is a specific process for inhibiting actions that have been prepared and consciously intended: anterior frontomedial cortex |
| |
marcel |
perform well-formed actions in response to environmental cues - these actions are contrary to the patient's will, occur w/o preceding conscious intention - anarchic hand syndrome. |
| |
della sala et al |
patient reaches to grasp a cup, despite just commenting that she would leave it to cool |
| |
boccardi et al (2002) |
utilisation behaviour: bilateral sma lesion - failure to inhibit unwanted movement. induced by situation. lesions of sma release unwanted stimulus driven actions. normal function of sma must be to inhibit such actions until we want to do them. a major element of 'wanting to do this' may be 'wanting not to do that'. both excitatory and inhibitory aspects of volition are housed in sma |
