The effects of subthreshold transcranial magnetic stimulation (TMS) on simple and go/no-go reaction time (RT) tasks were studied in seven healthy volunteers. Subjects were asked to respond by abducting the thumb in a warning-imperative signal paradigm. TMS was randomly delivered at variable delays to the imperative signal (IS). Simple RT was significantly shortened when TMS was delivered to the left motor cortex and parietal regions simultaneously with IS. In the go/no-go paradigm, a similar trend to shorter RT was seen at a delay of 0 ms. Additionally, a significant shortening was observed at a delay of 90 ms with TMS over the contralateral motor cortex only. Movement-related potentials (MRPs) in the two paradigms showed a predominantly contralateral negativity approximately 80 ms preceding EMG onset. Our findings support the existence of two differentiated effects of TMS on RT: (1) one non-specific effect, evidenced in both the simple and go/no-go paradigms at a 0 ms delay, which can be at least partially explained by intersensory facilitation; and (2) a motor-specific effect of TMS, unveiled in the go/no-go paradigm at a 90 ms delay.
|Number of pages||7|
|Journal||Experimental Brain Research|
|State||Published - 1999|
Bibliographical noteFunding Information:
Acknowledgements We wish to thank Dr. B Okuda, from Hyogo College of Medicine, for his invaluable suggestions during the planning of this study. We also gratefully acknowledge Dr. L.G. Cohen for inestimable comments in the final version of the present manuscript. This project was supported in part by a fellowship from the Ministry of Education, Science, Sports, and Culture of Japan, granted to L. Sawaki.
- Motor preparation
- Movement-related potential
- Reaction time
- Transcranial magnetic stimulation
ASJC Scopus subject areas
- Neuroscience (all)