Visual-Electrotactile Stimulation Feedback to Improve Immersive Brain-Computer Interface Based on Hand Motor Imagery

Table 4

Mean system perception levels on the Likert Scale from 1 to 7 of both feedback (F) groups (VIS: visual, VES: visual-electrotactile stimulation).

F	Ownership	Immersion	Attention	Difficulty
VIS	4.45  0.98	5.50  0.75	5.75  0.68	3.37  1.59
VES	4.15  0.75	4.80  1.30	5.90  0.84	2.80  1.20