Table 1.

Properties of connections between periphery nodes and the core.

A	B	C	D	E	F	G	H	I	J	K	L
Area	#FFo	#FBo	#FFi	#FBi	FFo−0.5	FBo−0.5	FFi−0.5	FBi−0.5	F+|I|	|G|+H	L/C/R
2	4	6	3	2	0.136	−0.205	0.063	−0.035	0.171	0.268	R
5	5	6	2	5	0.225	−0.083	0.157	−0.205	0.430	0.240	L
7B	8	3	7	4	0.154	−0.328	0.069	−0.233	0.388	0.397	R-C
DP	10	1	2	11	0.203	−0.268	0.018	−0.158	0.361	0.287	L
F1	6	8	0	8	0.187	−0.253	N/A	−0.073	0.260	0.253	L-C
MT	6	4	4	7	0.384	−0.015	0.174	−0.377	0.760	0.189	L
ProM	2	7	4	2	0.104	−0.199	0.255	−0.145	0.249	0.453	R
TEO	3	4	6	8	0.211	−0.029	0.247	−0.434	0.645	0.276	L
TEpd	3	8	2	8	0.065	−0.336	0.157	−0.104	0.168	0.493	R
V1	3	1	0	4	0.318	−0.500	N/A	−0.442	0.760	0.0	L
V2	8	4	0	5	0.277	−0.260	N/A	−0.394	0.671	0.260	L
V4	8	1	1	6	0.395	−0.500	0.074	−0.463	0.858	0.074	L

All the individual links of an area from P (column A) have been classified into one of four classes. If a link had an SLN > 0.5, it was designated as FF, otherwise as FB. The index “o” indicates connections from the node to the core, and the index “i” indicates connections from the core into that node. Columns B to E give the number of links of a given type for an area. Columns F to I provide the cumulative effective SLN values (see below) for the four types of connection groups (streams) after subtracting 0.5 from the values. The closer the value to 0.5 (−0.5), the stronger the effective FF (FB) nature of the group of links is. The cumulative effective SLN values were obtained as follows. Let L_j (x) denote the set of nodes in the C that a node x in the P connects with via a link of type j (one of the four types). The effective SLN measure S_j(x) for node x for its connectivity with C, within every link class, weighted by the strength (FLN) of the connections is given by S_j(x) = (Σy∈L_j(x)s_xyf_xy)/Σy∈L_j(x)f_xy. Here f_xy is the FLN and s_xy is the SLN; s_xyf_xy is thus proportional to the number of supra neurons in that individual (x-y) projection, which is then summed over all connections within that class that node x has with C, normalized by the total strength of the connections within that class. Exploiting the correlations between the streams shown in Fig 4, A to C, we generated in columns J and K two counterstream indices by adding the absolute values of the paired columns. If the outstreams into the C were strong FF (correlated with strong FB from the core), we designated them as L (left wing of the bow tie), otherwise as R (right wing). According to these criteria, TEpd is an outlier; see legend of Fig. 4.