Objective: Auditory event-related potentials (P-300-ERPs) were analyzed bef
ore and after repetitive transcranial magnetic stimulation (rTMS).
Methods: Two rTMS trains (10 Hz, 3 s, 100% motor threshold and 5 min interv
al) were delivered over the left frontal area in healthy subjects. P-300-ER
Ps were recorded at 14 electrode sites on the scalp using a typical oddball
paradigm before and after rTMS. The latencies and amplitudes of N-100, P-2
00, N-200(X) and P-300 were measured and compared. The directed coherence (
DCOH) was estimated to demonstrate information Row between different cortic
Results: rTMS significantly influenced P-300-ERPs. The effects differed on
the different components (P < 0.001). The latency of P-300 significantly in
creased after stimulation, which was more obvious in the frontal and centra
l areas. The changes in P-300 amplitude were not significant (P > 0.05). Th
e DCOH from the frontal. central, parietal and occipital areas to the tempo
ral area was significantly higher than the DCOH from the temporal area to t
he former 4 areas (P < 0.01).
Conclusions: rTMS with the present parameters can affect P-300-ERPs, leadin
g to a delayed P-300 component and changes in information connections aroun
d the stimulated site. Our data suggest that rTMS may postpone neuronal act
ivities related to cognitive processing. (C) 2001 Elsevier Science Ireland
Ltd. All rights reserved.