Figure 6

Possible confounding factors in immediate (online) task performances and delayed (offline) skill consolidation.
The confounding factors (i–v) could manipulate training–retest Go/Nogo task performance. Although the statistical analyses results demonstrate that the offline improvement in Go/Nogo response time (RT) seems to be directly influenced by the time-of-day effect (ii), the potent time-of-day effect on the online task performance of Go/Nogo RT could make it appear as though there was offline improvement (iv). The effects of sleep/wake state (i), training–retest time duration (iii) on offline RI skill consolidation and the effect of alertness (v) on online RI performances were statistically ruled out.