Herbal Extracts That Reduce Ocular Oxidative Stress May Enhance Attentive Performance in Humans

Figure 1

One trial in the attention network (ANT) test. A fixation cross appeared in the center of the screen at all times. Then, one of three cue types (none, center, and spatial) appeared for 200 msec. After a random interval (300–11800 msec, mean = 2800 msec), the target stimulus (upper/lower locations and left/right congruent or incongruent arrows) appeared until the subject responded. The duration of the presentation was 2000 msec at most. As soon as a subject pressed the button, the target stimulus disappeared. The next trial began after an intertrial interval that varied randomly and included a reaction time of 3000–15000 msec, mean = 6000 msec.