Theta-burst transcranial magnetic stimulation over the supplementary motor area decreases variability of temporal estimates
Abstract
OBJECTIVES: Supplementary motor area (SMA) was suggested to have a dominant role in the temporal control of behavior by many neuroimaging studies. The aim of this study was to support this hypothesis by influencing time estimates with theta burst transcranial magnetic stimulation (TMS) over the SMA.
METHODS: Nineteen healthy volunteers with a mean age 25.9 +/- 3 (SD) years performed the time reproduction task (TRT) before and after 190 seconds of intermittent theta-burst TMS over SMA and the precuneus (total 600 pulses). The TRT consisted of an encoding phase (during which visual stimuli with durations of 5, 10 and 16.82 seconds were presented pseudorandomly) and a reproduction phase (during which interval durations were reproduced by pressing a button).
Mean subjects' interval estimates as a measure of accuracy and standard deviation as a measure of variability pre-TMS and post-TMS were compared. RESULTS: Theta-burst TMS over both areas had no effect on the accuracy of duration estimates.