Table 1.

Hierarchical regressions of conflict cost, baseline reaction time, and age on cognitive mechanics and processing fluctuation

Age group	Cognitive mechanics (Gf)	Processing fluctuation
6–17 years
Raw R2	0.073**	0.071**
Hierarchical regression
Predictor	Incremental R2
Baseline RT	0.44***	0.43***
Age	0.30***	0.071**
Conflict cost	0.003	0.009
18–55 years
Raw R2	0.03	0.006
Hierarchical regression
Predictor	Incremental R2
Baseline RT	0.071*	0.30***
Age	0.20***	0.02
Conflict cost	0.057**	0.004
56–89 years
Raw R2	0.093**	0.071**
Hierarchical regression
Predictor	Incremental R2
Baseline RT	0.12***	0.30***
Age	0.25***	0.14***
Conflict cost	0.04*	0.04*

* p < 0.05, ** p < 0.01, *** p < 0.001