Table 2.

Effect of difficulty level in the frontal lobe ROIs.

Contrast	ROI	Con	t	p corrected
Positive effect of condition	Left IFO	0.76	2.17	0.061
	Right IFO	1.07	2.97	0.007
	Right IFS	1.65	4.34	< 0.001
	Left IFG	1.29	3.46	0.001
Contrast	ROI	Con	F	p corrected
Main effect of time	Left IFO	2.05	2.07	0.13
	Right IFO	2.46	2.38	0.058
	Right IFS	4.05	3.60	0.001
	Left IFG	4.36	4.07	< 0.001

Numbers in bold are significant at the p < 0.05 threshold.