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Table 3 Results of the users’ performance in the virtual navigation session

From: Brain-Computer Interface application: auditory serial interface to control a two-class motor-imagery-based wheelchair

Participant Time lapse Failed commands IC changes Classification matrix’s measures
Absolute Relative F R L Total Recall Specificity Precision NPV Accuracy
  Virtual navigation task 1: visual-auditory interface
A1 215 1.09 0 0 0 0 0 .94 1.00 1.00 .92 .97
A2 381 1.92 2 0 11 13 0 .85 .67 .57 .90 .73
A6 432 2.18 1 0 0 1 1 .81 .96 .94 .85 .89
A8 312 1.80 1 0 7 8 0 .89 .65 .68 .88 .76
A9 294 1.48 0 1 1 2 0 .94 .86 .89 .92 .91
A12 284 1.43 1 0 2 3 0 .94 .75 .85 .90 .87
B13 413 1.78 1 0 2 3 1 .63 .92 .85 .78 .80
B14 392 1.98 2 1 0 3 0 .81 .80 .85 .75 .81
B15 284 1.43 0 0 4 4 0 1.00 .67 .81 1.00 .86
Average 334 ± 73 1.68 ± 0.34 0.89 ± 0.78 0.22 ± 0.44 3.00 ± 3.78 4.11 ± 4.01 0.22 ± 0.44 .87 ± .11 .81 ± .13 .83 ± 13 .88 ± .08 .84 ± .08
  Virtual navigation task 2: auditory interface
A1 246 1.24 2 0 0 2 0 .89 .86 .89 .86 .88
A2 513 2.59 0 6 25 31 0 1.00 .39 .35 1.00 .54
A6 410 2.09 1 3 3 7 0 .89 .63 .71 .86 .76
A8 251 1.27 0 1 1 2 0 1.00 .80 .89 1.00 .93
A9 303 1.53 2 0 0 2 0 .85 .85 .89 .79 .85
A12 278 1.40 0 1 0 1 0 .94 .92 .94 .92 .93
B13 644 3.25 4 0 0 4 8 .41 .95 .81 .76 .76
B15 252 1.27 0 0 1 1 0 1.00 .89 .94 1.00 .96
Average 362 ± 148 1.83 ± 0.75 1.13 ± 1.48 1.38 ± 2.13 3.75 ± 8.65 6.25 ± 10.20 1 ± 2.83 .75 ± .36 .79 ± .19 .80 ± .20 .90 ± .10 .83 ± .14
  1. The Relative time is calculated by comparing the Absolute Time and the time obtained on a reference path in which, once a selection is made, the NC interface is presented for the selection of a new command (in this way, a subject can only make one selection per IC interface)