Further work will be required to determine whether the alternating rule of the PGNG and the increased number of targets are tapping the same underlying deficit, as represented by high scores on Cognitive Complexity. A notable absence was any effect of Motor Impulsiveness and Attentional Impulsivity that Keilp et al. (2005) identified with their standard Go/No-go task. We would suggest that the impact the increase in complexity has on performance is such that the influence of more basic aspects of impulsivity such as, for example, acting without thinking (Motor Impulsiveness) and quick decision making (Attentional impulsivity; Patton et al., 1995), are overshadowed on these complex forms of inhibition task, whereas the relative ease of the standard Go/No-go task leaves more room for these aspects of impulsivity to be observed.