Adult age differences in the Color Stroop Test: A comparison between an Item-by-item and a Blocked version

The Color Stroop Test is consensually considered as a task to assess the efficiency of inhibitory mechanisms. If the Stroop interference effect is largely undisputed, it is also acknowledged that the size of this effect varies as a function of various task manipulations, such as the task format. The aim of the present study was to compare the size of adult age-related differences in inhibition as assessed by two different versions of the Color Stroop Test: a standard Blocked paper-and-pencil version and a computerized Item-by-item one. Results showed pronounced age-related differences in the interference effect in the Blocked version, but not in the Item-by-item one. These findings are discussed in terms of the characteristics of the tasks. The choice of the appropriate version with respect to clinical aims is also addressed.