When a person smokes or snorts cocaine, it reaches all areas of the brain, but it binds to sites in some very specific areas. These are highlighted with the yellow dots: the VTA, the nucleus accumbens, and the caudate nucleus (the largest structure). Point out that cocaine binds especially in the reward areas that you have just discussed. The binding of cocaine in other areas such as the caudate nucleus can explain other effects such as increased stereotypic (or repetitive) behaviors (pacing, nail-biting, scratching, etc..)