The impact of transcranial magnetic stimulation on cognitive processing:: an event-related potential study

Several neuropsychological studies have shown that repetitive transcranial magnetic stimulation (rTMS) can improve cognitive processing. We performed a study on the impact of rTMS on cognitive processing as measured by a neurophysiological method. In 14 healthy subjetcs, visually evoked event-related potentials (ERP) and mean choice reaction time were measured before and after 20 Hz rTMS of the left and of the right prefrontal cortex. The data were compared to sham stimulation and to 1 Hz single TMS. P3 latencies and reaction time were significantly decreased by rTMS of the left but not of the right prefrontal cortex, single TMS did not have any significant impact on the ERP components. We conclude that the facilitating effects of rTMS on cognitive processing can be proven even by objective neurophysiological measures. NeuroReport 12:2915-2918 (C) 2001 Lippincott Williams & Wilkins.