Fig 6. The stimuli presentation diagram for single session: A single session consisted of 10 trials presenting m-sequence or chaotic code visual stimuli.

Each trial had 18 consecutively presented epochs. Each epoch presented a single visual stimulus code. Each trial was followed by 2 second break time. As there were 4 m-sequence (M₁ − M₄) and 4 chaotic codes (Ch₁ − Ch₄), each subject had total 8 sessions of stimulus presentation (see Fig 7 and text for details).