Table 1.

Hub regions in the cortical 154-node network revealed by weighted degree and betweenness centrality

	Synesthetes				Nonsynesthetes
	Rank	Node	Absolute centrality	Normalized centrality	Rank	Node	Absolute centrality	Normalized centrality
Degree	1	r_CgS_i	42.4	0.2756	1	r_MTG	28.5	0.1851
	2	l_IFS	36.6	0.2374	2	l_FuG	26.7	0.1732
	3	l_FuG	35.9	0.2333	3	r_CgS_i	26.3	0.1708
	4	r_SOG	35.3	0.2292	4	r_OFG	24.6	0.1598
	5	l_InsG_L	32.8	0.2130	5	l_FMG	24.5	0.1592
	6	l_TMP	32.1	0.2083	6	r_SbGG	24.1	0.1564
	7	r_OCP	32.0	0.2079	7	r_SOG	23.3	0.1511
	8	l_OFS_H	31.8	0.2065	8	r_ITG	22.8	0.1480
	9	r_ITG	31.0	0.2014	9	r_Cun	22.3	0.1448
	10	l_TTS	31.0	0.2014	10	l_IFS	22.1	0.1435
	11	r_SPL	31.0	0.2010	11	r_InsG_L	21.6	0.1400
	12	l_IMS_pJ	30.6	0.1988	12	l_SbPS	21.5	0.1397
	13	r_LF_av	30.2	0.1960	13	l_OFS_H	20.7	0.1343
	14	r_CG_I	29.9	0.1943	14	l_CG_M	19.7	0.1282
	15	r_TTS	29.8	0.1933	15	r_IFG_Op	19.6	0.1270
	19	r_FuG	28.1	0.1824	48	r_FuG	12.3	0.0797
	22	r_IPS	27.2	0.1765	108	r_IPS	6.1	0.0393
	68	l_IPS	15.4	0.1002	112	l_IPS	5.7	0.0372
Betweenness centrality	1	l_Pcu	643.4	0.0553	1	r_POS	544.7	0.0468
	2	r_SFG	408.8	0.0352	2	l_SFG	432.2	0.0372
	3	r_POS	353.0	0.0304	3	l_POS	420.9	0.0362
	4	l_SFG	298.1	0.0256	4	l_Pcu	399.1	0.0343
	5	l_IFG_Op	286.0	0.0246	5	l_SbCG	362.2	0.0311
	6	l_IFG_Tr	258.0	0.0222	6	l_IPS	332.3	0.0286
	7	l_AOS	255.0	0.0219	7	l_AnG	309.9	0.0266
	8	r_CG_M	232.6	0.0200	8	l_CG_M	304.2	0.0262
	9	l_InsS_Ca	207.7	0.0179	9	l_LiG	297.3	0.0256
	10	l_MTG	207.4	0.0178	10	r_MTG	287.3	0.0247
	11	l_LiG	195.1	0.0168	11	l_ITG	245.1	0.0211
	12	l_AnG	190.5	0.0164	12	r_IFG_Tr	242.9	0.0209
	13	r_Cun	185.9	0.0160	13	l_PCL	239.3	0.0206
	14	l_PrCS_S	175.8	0.0151	14	l_SMG	238.0	0.0205
	15	r_OTS_m	168.6	0.0145	15	l_STS	231.3	0.0199
	28	l_IPS	130.8	0.0112	37	r_FuG	116.4	0.0100
	45	l_FuG	98.0	0.0084	44	l_FuG	91.2	0.0078
	74	r_IPS	43.4	0.0037	95	r_IPS	37.2	0.0032
	94	r_FuG	28.1	0.0024

Shown are the 15 largest hub regions. The ranks of the left and right FuG and IPS are shown also. Note the significantly higher degree centrality scores of the 15 largest hubs in synesthetes compared with nonsynesthetes (two-sample t test, p ≪ 0.0001). Although nonsynesthetes showed Increased betweenness centrality scores, this difference is not statistically significant (p = 0.21). Normalized degree centrality is computed by dividing the absolute degree by the number of nodes (154) in the network. Normalized betweenness centrality scores were computed by dividing the absolute betweenness by [(1/2) × (154 − 1) × (154 − 2)]. The values of the FuG and IPS are printed in bold. For the code of the structural parcellation labels, see supplemental Table S2 (available at www.jneurosci.org as supplemental material).