Methods and stimuli.
(A) An example of eye movements during reading. The lines of text are an excerpt from one of the paragraphs used in the study. The size of the foveola (the high-acuity region of the retina) is also shown for comparison. Different types of eye movements are color-coded. (B) Accuracy in gaze localization. Error in gaze localization for one subject, each dot represents the offset between the gaze position and the fixated marker in an individual repetition of the calibration procedure (see Methods for details). The 99% confidence ellipse and the marginal distributions with their Gaussian fits are also shown. The numbers on the graph indicate horizontal and vertical standard deviations of the distribution. (C) Number of characters spanned as a function of saccade size. The shaded area in the graph represents the microsaccade range. Data points are averages across observers, and error bars represent s.e.m.