Abstract
The effects of transcranial magnetic stimulation were studied on the performance of a warned, forced-choice response time task by normal adults. The task consisted of extension of the index finger in response to the click produced by the discharge of the magnetic coil (go-signal). The subjects were asked to choose the right or left finger only after the go-signal was delivered. Single magnetic stimuli were delivered to the prefrontal or motor area, and in the control situation, away from the head. Magnetic stimulation affected hand preference only when it was delivered to the motor area. With stimulation of this area, subjects more often chose the hand contralateral to the site stimulated with response times that were mainly less than 200 ms. With longer response times (between 200 and 1100 ms), magnetic stimulation had no effect on hand preference regardless of the site stimulated. Stimulation of prefrontal areas yielded results similar to the control situation. These results suggest that response bias in this paradigm is caused by an effect of magnetic stimulation on neural structures within, or closely related to, the motor areas of the brain. Although the response bias was clear and predictable, the subjects were unaware of its existence. It is possible to influence endogenous processes of movement preparation externally without disrupting the conscious perception of volition.
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Selected References
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- Ammon K., Gandevia S. C. Transcranial magnetic stimulation can influence the selection of motor programmes. J Neurol Neurosurg Psychiatry. 1990 Aug;53(8):705–707. doi: 10.1136/jnnp.53.8.705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen L. G., Bandinelli S., Sato S., Kufta C., Hallett M. Attenuation in detection of somatosensory stimuli by transcranial magnetic stimulation. Electroencephalogr Clin Neurophysiol. 1991 Oct;81(5):366–376. doi: 10.1016/0168-5597(91)90026-t. [DOI] [PubMed] [Google Scholar]
- Cohen L. G., Roth B. J., Nilsson J., Dang N., Panizza M., Bandinelli S., Friauf W., Hallett M. Effects of coil design on delivery of focal magnetic stimulation. Technical considerations. Electroencephalogr Clin Neurophysiol. 1990 Apr;75(4):350–357. doi: 10.1016/0013-4694(90)90113-x. [DOI] [PubMed] [Google Scholar]
- Cohen L. G., Topka H., Cole R. A., Hallett M. Leg paresthesias induced by magnetic brain stimulation in patients with thoracic spinal cord injury. Neurology. 1991 Aug;41(8):1283–1288. doi: 10.1212/wnl.41.8.1283. [DOI] [PubMed] [Google Scholar]
- Day B. L., Rothwell J. C., Thompson P. D., Maertens de Noordhout A., Nakashima K., Shannon K., Marsden C. D. Delay in the execution of voluntary movement by electrical or magnetic brain stimulation in intact man. Evidence for the storage of motor programs in the brain. Brain. 1989 Jun;112(Pt 3):649–663. doi: 10.1093/brain/112.3.649. [DOI] [PubMed] [Google Scholar]
- Dunlap K. VISUAL SENSATIONS FROM THE ALTERNATING MAGNETIC FIELD. Science. 1911 Jan 13;33(837):68–71. doi: 10.1126/science.33.837.68-a. [DOI] [PubMed] [Google Scholar]
- Gratton G., Coles M. G., Sirevaag E. J., Eriksen C. W., Donchin E. Pre- and poststimulus activation of response channels: a psychophysiological analysis. J Exp Psychol Hum Percept Perform. 1988 Aug;14(3):331–344. doi: 10.1037//0096-1523.14.3.331. [DOI] [PubMed] [Google Scholar]
- Libet B., Gleason C. A., Wright E. W., 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. 1983 Sep;106(Pt 3):623–642. doi: 10.1093/brain/106.3.623. [DOI] [PubMed] [Google Scholar]
- Oldfield R. C. The assessment and analysis of handedness: the Edinburgh inventory. Neuropsychologia. 1971 Mar;9(1):97–113. doi: 10.1016/0028-3932(71)90067-4. [DOI] [PubMed] [Google Scholar]