Table 4.

Anatomical locations and MNI coordinates of the peak activations showing an interaction effect between age and willingness to engage in 20% physical effort

			MNI coordinates
Region	Hem	BA	x	y	z	K	t
Frontopolar cortex	R	10	24	62	27	20	3.87
Insula	R	13	36	−6	2	29	3.55
Supplementary motor area	L	6	−9	−14	63	21	3.55

The frontopolar cortex cluster is significant after applying small-volume correction within a spherical mask centered on the coordinates for the FPC tDCS electrode placement (see main text). The results in the insula and supplementary motor area do not survive corrections for multiple comparisons at the whole brain level (P < 0.001 uncorrected, minimum cluster size k ≥ 20 voxels) but are reported here for completeness and to facilitate the formation of future hypotheses and replication studies. We do not make any inferences on these insula and supplementary motor area results in the current manuscript. Hem = hemisphere (L = left, R = right); BA = Brodmann area.