Table 1.

Frequency and amplitude of D- and I-wave generation from different cortical areas

Cortical stimulus site	Number of sites generating D waves (percentage)	Number of sites generating I waves (percentage)	Number of sites generating neither D nor I waves (percentage)	Amplitude of D wave (mean ± SEM, μV)	Amplitude of I1 wave (mean ± SEM, μV)
New M1	14/18 (78%)	15/18 (83%)	3/18 (17%)	31.9 ± 9.5	27.5 ± 9.2
Border region	5/6 (83%)	5/6 (83%)	1/6 (17%)	7.5 ± 3.4	4.0 ± 1.3
Area 3a	2/10 (20%)	2/10 (20%)	8/10 (80%)	5.8 ± 2.3	2.4 ± 1.3
Old M1	10/14 (71%)	10/14 (71%)	4/14 (29%)	22.4 ± 9.4	28.5 ± 12.8