This cognitive psychology book presents the results of an experimental study consisting of determining the effect of two factors (the spatial arrangement of items and affordance based on colour) in the Trail Making Test and visual search when consulting content on websites. Used by clinicians, this test measures the speed of performing a cognitive task (going from one number to the next) at the attentional level (looking for the next number) involving visual-spatial processes. In this study, it is not a question of detecting an item among other items as in the research conducted by Charles Tijus (2003), distinguishing an object among others by an actionable property, or by Laure Léger on pop-out and masking (Léger, Tijus, 2007), but of choosing an easy path to move in an increasing manner from one item to another item. The author shows that thanks to visual affordance, the results of the computerised Trail Making Test are better than those of the paper-based Trail Making Test. He shows that the use of this concept also facilitates visual search.