The gaze-shift strategy in drawing

Alternating the point of gaze between an original (model or sitter, object, or scene) and a picture (paper, canvas, or digital touch screen) is the most common observational drawing strategy. However, a number of investigations into eye-hand interactions in drawing have revealed the existence of some "blind" drawing taking place (drawing the picture while the eye remains on the original or during gaze shifts between the original and the drawing). These observations of a direct visual-to-motor transformation challenge the commonly held assumption that the gaze-shifting strategy reflects a memory process in which the gaze on the original is used to encode a visual detail to short or long term memory, subsequently retrieved during the gaze on the picture. To study the blind drawing strategy in more depth during naturalistic drawing, we compared 3 basic drawing tasks-copying, contouring, and drawing of graded zones as lines, where original and picture were placed side by side on a vertical plane. We found that subjects drew almost continuously, thus exhibiting periods of blind drawing while the eye was on the original. The amount of blind drawing increased progressively between the copying task, the contouring task, and the graded zone task. When gaze shifted to the picture, it was generally to a fixation point located in advance of the hand on the part of the line not yet drawn. For individual tests, gaze ratios (gaze duration on original divided by gaze duration on picture) were approximately equal to drawing ratios (drawing duration during original gaze divided by drawing duration during picture gaze). We propose a general gaze-shift strategy that takes into account these observations.