In this experiment (Plane, S., Alamargot, D. & Chesnet, D., 2005), a professionnal writer is asked to resume a text.
The subject wears an Eyelink2 eyetracker (headmounted), which allows to record her eye movements while reading the incipit and while writing her own text.
She wrote on an LCD tablet, which allows to read the text incipit while writing on a single surface, which is also convenient way to manage the eyetracking device data.
As one may see, the pen “trace” is drawn on the display.
A closer view …