Homo Sapiens Reading

Reading is a standard day-to-day activity of a modern human being. It includes three components: sensoric (perception of visual stimulus – letters and other characters), motoric (eyes’ movements) and cognitive (attention, memory, and character and word recognition). The reading process requires quick eye movements – saccades, which move the eyes quickly from one text fragment to another. Only the retina’s central part, which contains cones, is capable of recognizing objects (characters). This dictates the necessity of quick eyes’ movements to project each successive text fragment exactly to the retina’s central part. To recognize objects it is necessary to fix the glance and the eye stays static for 100-200 ms. Then follows another saccade and another fixation.

The video-oculographic system determines eye coordinates based on the analysis of the infra-red light reflected from the surface of different parts of the eyeball. It is the position of the darker pupil in the infra-red light that coincides with the eye coordinates.

The research was aimed at studying the effect of the text’s properties on the parameters of eye movements in the process of reading such texts. For this purpose, the testees – students aged 19 to 23 years, were asked to read four text fragments on the monitor screen, their line length being 83, 62, 40 and 30 characters (font: Arial 16) with a single line spacing, and then – four text fragments with the same line length and 1.5 line spacing. All fragments represented an educational text on psychology. The testees were instructed to read the text to the end at an arbitrary speed. In another research the testees were offered text fragments typed in small-size (Arial 9) and large-size (Arial 16) fonts.

The results of the experiments demonstrate certain regularities inherent in the reading process. Thus, the reading time depends on the number of characters in the text but it is independent of the interline spacing. The speed of reading somewhat increased with the increase of the line length, it was higher when the line spacing was 1.5 line in comparison with a single line spacing and at the same time there was no correlation with the font size. The number of characters read during a fixation (informational capaciy of fixations)also increased with the line length. The fixation capacity was higher when reading a text typed in a small-size font than in a large-size font. The testees fixed their eyes more often in the beginning (first third part) of each line than in the end.

It turned out that, when reading, the testees often reread previous text fragments because of their wrong initial perception and for better understanding. In general, there was no correlation between the text properties and the number of times it was reread (the number of times the eyes returned to the previous text fragment).

The received correlations can be applied to estimate the extent of the text’s perception, exhaustion threshold and attention decrease when a monotonous task is fulfilled. It will be possible to define the optimal characteristics of a text – line length and interline spacing – for its better perception. To maintain the required level of attention, it is possible, for example, to highlight informatively important words or use other methods. And this will be very helpful in compiling textual materials for educational purposes.