Group averages on symmetric template. (a) All the pits from every individual projected onto the left fsaverage_sym template (presented with external, internal, bottom, and top views of the left hemisphere). (b) Density map corresponding to the sum of the smoothed pits map across subjects and across hemispheres. (c) Average DPF map corresponding to the same sum as for the density map. (d) Group-level sulcal basins obtained after performing the watershed on the density map. Nomenclature of our areals mainly based on existing literature (Im et al. 2010; Meng et al. 2014). 1 mid frontal a, 2 sup frontal a, 3 mid frontal b, 4 sup frontal b, 5 mid frontal c, 6 junct sup frontal and precentral, 7 precentral, 8 junct precentral and inf frontal, 9 inf frontal b, 10 inf frontal a, 11 central a, 12 central b, 13 central c, 14 postcentral a, 15 postcentral a bis, 16 postcentral b, 17 postcentral c, 18 intraparietal a, 19 intraparietal b, 20 intraparietal c, 21 supra marginal gyrus, 22 junct intraparietal and sup temporal, 23 sup temporal a, 24 sup temporal b, 25 sup temporal c, 26 sup temporal d, 27 temporale pole, 28 inf temporal a, 29 inf temporal b, 30 inf temporal c, 31 inf temporal d, 32 occipito temporal a, 33 occipito temporal b, 34 collateral a, 35 collateral b, 36 collateral c, 37 collateral d, 38 orbital, 39 olfactory, 40 cingulate a, 41 cingulate b, 42 cingulate c, 43 cingulate d, 44 cingulate e, 45 supplementary motor area, 46 below subparietal and cingulate, 47 subparietal, 48 subparietal b, 49 lateral occipital a, 50 junct collateral and calcarine a, 51 junct collateral and calcarine b, 52 calcarine a, 53 calcarine b, 54 calcarine c, 55 lateral occipital b, 56 parieto-occipital a, 57 parieto-occipital b, 58 circular insular a, 59 circular insular b, 60 circular insular c, 61 circular insular d, 62 circular insular e, 63 planum temporale area, 64 planum parietale.