Table 2. Classification statistics.
(A) Number of days with CA above chance level; (B) number of delivered sentences with CA above chance level; (C) maximum chance-level upper limit, calculated using the metric described in BCI effectiveness metric section; and (D) mean and standard deviation of CA above chance level, obtained using the fNIRS, EEG, and EOG signal data for patients F, G, B, and W. For the training sessions, the CA is reported for fNIRS, EEG, and EOG signals. For feedback and open question sessions, CA is only reported for the fNIRS signal because the feedback was provided using only the fNIRS signal as a result of superior CA of the fNIRS signal during the training sessions as compared to EEG and EOG signals. Table 2 data is located at https://doi.org/10.5281/zenodo.191884; https://doi.org/10.5281/zenodo.191887; https://doi.org/10.5281/zenodo.191891; https://doi.org/10.5281/zenodo.191899.
| Patient (sessions’ type) | A) Number of days with CA1 above chance | B) Number of sentences with CA1 above chance | C) Max chance-level upper limit | D) Mean CA1 of sessions above chance-level upper limit |
|---|---|---|---|---|
| (n.2/tot.3 = %4) | (n.5/tot.6 = %7) | (%8) | (mean%9 ± std%10) | |
| fNIRS classification accuracy | ||||
| F (training) | 11/14 = 78.6 | 929/1,020 = 91.1 | 64.8 | 69.5 ± 4.4 |
| F (FB* & OQ++) | 3/4 = 75.0 | 120/200 = 60.0 | 70.0 | 78.6 ± 6.9 |
| G (training) | 14/17 = 82.3 | 703/1,020 = 68.9 | 64.8 | 69.4 ± 4.2 |
| G (FB* & OQ++) | 4/5 = 80.0 | 80/160 = 50.0 | 70.0 | 78.8 ± 8.5 |
| B (training) | 9/12 = 75.0 | 630/800 = 78.7 | 64.8 | 69.6 ± 5.6 |
| B (FB* & OQ++) | 2/2 = 100.0 | 120/120 = 100.0 | 70.0 | 75.8 ± 6.6 |
| W (training) | 5/6 = 83.3 | 256/320 = 80.1 | 64.8 | 72.3 ± 4.3 |
| W (FB*) | 1/3 = 33.3 | 20/80 = 25.0 | 70.0 | 70.0 ± 0.0 |
| EEG classification accuracy | ||||
| F (training) | 7/14 = 50.0 | 546/1,020 = 53.5 | 64.8 | 65.7 ± 2.9 |
| G (training) | 6/17 = 35.3 | 555/1,020 = 54.4 | 64.8 | 66.0 ± 3.5 |
| B (training) | 2/12 = 16.7 | 44/800 = 5.5 | 64.8 | 67.5 ± 0.0 |
| W (training) | 4/6 = 66.7 | 254/320 = 79.5 | 64.8 | 68.9 ± 5.3 |
| EOG classification accuracy | ||||
| F (training) | 5/14 = 35.7 | 491/1,020 = 48.1 | 64.8 | 64.3 ± 2.6 |
| G (training) | 12/17 = 70.6 | 722/1,020 = 70.8 | 64.8 | 69.9 ± 5.5 |
| B (training) | 3/12 = 25.0 | 226/800 = 28.3 | 64.8 | 65.4 ± 1.9 |
| W (training) | 5/6 = 83.3 | 299/320 = 93.4 | 64.8 | 70.1 ± 4.3 |
1Classification accuracy.
2Number of days with fNIRS classification accuracy above chance-level threshold.
3Total number of days in which training or feedback and open question sessions were performed.
4Percentage of days for which fNIRS classification accuracy was above chance-level threshold.
5Number of delivered sentences with fNIRS classification accuracy above chance-level threshold.
6Total number of sentences delivered during training or feedback and open question sessions.
7Percentage of sentences for which fNIRS classification accuracy was above chance-level threshold.
8Maximum chance level threshold (or chance-level upper limit).
9Mean fNIRS classification accuracy of sessions above chance-level threshold.
10fNIRS classification accuracy standard deviation of sessions above chance-level threshold.
*FB: Feedback session during which participant received feedback for known questions.
++OQ: Open question session during which participant received feedback for open questions.