Table 2.

Effective connectivity

ConnectionsIntrinsic connectivityaModulation of SMALLbModulation of LARGEbSMALL vs LARGEc
Rate constantsSEMp valuesRate constantsSEMp valuesRate constantsSEMp valuesRate constantsp values
V3A to V6A0.4680.0640.0000.099 (21%)0.0300.0040.031 (7%)0.0110.015d0.0680.045d
V3A to AIP0.2160.0780.014d0.066 (31%)0.0230.0100.003 (1%)0.0210.8950.0640.032d
V6A to PMd0.4210.0680.0000.019 (5%)0.0110.1000.014 (3%)0.0050.0090.0040.379
AIP to PMv0.2510.0930.016d0.026 (10%)0.0080.0070.007 (3%)0.0060.2300.0190.030d
AIP to V3A0.0730.0190.001
V6A to V3A0.1110.0320.003
PMv to AIP0.0380.0120.006
PMd to V6A0.0680.0200.003
INPUT to V3A0.1580.0280.000
  • aAverage rate constants [rate of change of neuronal activity (hertz) in one area as induced by another] over subjects for the intrinsic connections and their p values. The intrinsic connectivity refers to the impact that one region exerts over another on the basis of the overall experimental context, rather than in relation to a precise experimental perturbation.

  • bThe modulatory effects of object size on the forward connections over subjects (i.e., changes in connection strength). Rate constants are expressed in real values and in percentage change relative to the intrinsic connectivity.

  • cA contrast (SMALL vs LARGE) testing whether the interregional couplings are more strongly modulated during grasping a SMALL than during grasping a LARGE object.

  • dSignificant results that would not survive Bonferroni correction.