Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

Table 1 Mean Δ[O₂Hb] and Δ[HHb] profiles.

Mean Δ[O₂Hb] Δ[HHb] Overall-subjects	Channel 1	Channel 2	Channel 3	Overall channels
MI-simple
Δ[O₂Hb] μmol/l	0.101 ± 0.013	0.054 ± 0.014	0.038 ± 0.011	0.064 ± 0.012
Δ[HHb] μmol/l	-0.017 ± 0.002	-0.0130 ± 0.003	-0.011 ± 0.003	-0.014 ± 0.003
Δ[O₂Hb] SNR	0.99	0.54	1.08	0.87
MI-complex
Δ[O₂Hb] μmol/l	0.192 ± 0.012	0.095 ± 0.012	0.065 ± 0.010	0.118 ± 0.011
Δ[HHb] μmol/l	-0.008 ± 0.006	-0.010 ± 0.003	-0.007 ± 0.003	-0.009 ± 0.003
Δ[O₂Hb] SNR	1.04	1.23	1.55	1.27
Inter-task paired t-test [simple vs complex]	Channel 1	Channel 2	Channel 3	Overall channels
	Δ[O₂Hb] (p-values)	Δ[O₂Hb] (p-values)	Δ[O₂Hb] (p-values)	Δ[O₂Hb] (p-values)
Overall-subjects	≤ 0.001*	0.018*	0.064	≤ 0.001*
Subject 1	≤ 0.001*	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 2	0.341	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 3	1.000	0.003*	≤ 0.001*	0.032*
Subject 4	1.000	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 5	≤ 0.001*	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 6	0.105	0.007*	0.002*	0.046*
Subject 7	≤ 0.001*	0.023*	≤ 0.001*	≤ 0.001*
Subject 8	0.086	≤ 0.001*	0.004*	0.002*
Subject 9	≤ 0.001*	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 10	0.976	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 11	0.181	≤ 0.001*	≤ 0.001*	≤ 0.001*
Subject 12	0.324	0.026*	≤ 0.001*	0.039*

(Top) Mean Δ[O₂Hb] and Δ[HHb] (mean ± SE μmol/l) and Δ[O₂Hb] signal-to-noise ratio (SNR, defined as the ratio of the mean signal to its standard deviation) on the overall-subject-level averaged over channels 1-3 and for each channel separately, of the contralateral (right) hemispheres during performance of MI-simple and MI-complex (Bottom) Inter-task paired t-test (CI 95%, p-values) for each subject of Δ[O₂Hb] between the two tasks, MI-simple and ME-complex.
Significant values are highlighted with (*).

ISSN: 1743-0003