Differential effects of high and low-frequency TMS on different tactile perceptual tasks and cortical excitability of human somatosensory cortex

Objective: Repetitive transcranial magnetic stimulation (rTMS) is used as a tool to interfere in a systematic way with ongoing brain activity allowing a targeted induction of LTP- and LTD-like processes. We have recently shown that 5Hz TMS applied over somatosensory cortex (SI) can drive perceptual improvement in the tactile domain (Tegenthoff et al. 2005, PloS Biology). Here we asked, how different stimulation frequencies affect perceptual tactile tasks in parallel to changes of cortical excitability in SI. Material: To assess perceptual performance, we measured spatial 2-point discrimination, touch-threshold a…