Abstract
Transcranial magnetic stimulation (TMS) has been used to investigate cortical function in healthy subjects for decades. However, prolonged disruptive effects of of a single pulse of TMS has not been investigated. Currently, it appears there is no standardized time period between TMS stimulation in order to limit interference between trials. In this experiment we used a combination of transcranial magnetic stimulation (TMS) and electroencephalography (EEG) techniques to examine the temporal and spatial characteristics of an evoked potential across the brain. Subjects were fitted with an EEG cap according to standard 10-20 EEG system. TMS stimulation was applied with an MRI-guided sterotactic system to ensure that the appropriate cortical areas are accurately stimulated. Motor threshold (MT) is found via movement evoked potential (MEP) of the first dorsal interosseous muscle and was used to sample subjects at threshold and sub-threshold values. Multiple stimulation sites are sampled in order to compare TMS effects on different areas of the brain. The experiment session will include a third sample of sham TMS is included in the testing protocol in order to eliminate auditory artifacts TMS present in EEG recordings. The resulting findings will facilitate future research in TMS by providing an appropriate time interval to negate interference between stimulations.
