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Table 1 Laplace channel position, combination of motor imagery tasks and online BCI performance for every subject

From: Transcranial magnetic stimulation for individual identification of the best electrode position for a motor imagery-based brain-computer interface

Subject

BCI control tasks

ADM CoG-nearest electrode

Mu-modulation center

Significance

Laplace position

Online performance

Laplace position

Online performance

5

Right hand vs. feet

mC3

59 %

C3

96 %

***

8

Right hand vs. feet

mC3

87 %

C3

95 %

*

11

Right hand vs. feet

mC3

91 %

C3

92 %

n.s.

2

Right hand vs. feet

mC4

48 %

C4

92 %

***

4

Right hand vs. feet

mC3

65 %

C3

90 %

***

1

Right hand vs. feet

mC3

47 %

pC3

73 %

***

7

Right hand vs. feet

C3

37 %

lC3

72 %

***

6

Left hand vs. feet

mC4

57 %

pC4

64 %

n.s.

3

Right hand vs. feet

amC3

47 %

C3

56 %

n.s.

9

Right hand vs. feet

Identical with mu-modulation center

mC4

53 %

-

10

Left hand vs. feet

Identical with mu-modulation center

amC3

45 %

-

Mean of online performance

-

57.8 %

-

75.3 %

**

  1. Subjects are ranked by their online performance using the mu-modulation center. Most subjects showed a significantly better online BCI performance, when the mu-modulation center was used as the center of a next-neighbor Laplacian channel compared to the motor hand area. Prefixes of Laplace electrode positions: m = 23 mm medial to [electrode position] (Example: mC3 = 23 mm medial to C3), l = 23 mm lateral to [electrode position], a = 23 mm anterior to [electrode position], p = 23 mm posterior to [electrode position] (all electrode positions are also visualized in Fig. 2). Significance levels were *p < 0.05, **p < 0.01, ***p < 0.001 and n.s. p > = 0.05