Fig. 3From: Development of an electrooculogram-based eye-computer interface for communication of individuals with amyotrophic lateral sclerosisExperimental procedures of the three sessions for participants with ALS. a Instruction, b practice, c exercise. The numbers within the blanks denote the duration of image display. The sound images denote beeps or recorded verbal instructions (noted as Vx, where x denotes an instruction index). The verbal instructions consisted of cues for participant action. For the full instructions given to the participants, see Appendix Back to article page