Figure 3.

Areas activated when the weight of the object was unpredictably changed, regardless of whether it was lighter or heavier than predicted. We tested the main effect of change in object weight [(Change to heavier − No change heavy) + (Change to lighter − No change light); p < 0.05 corrected]. Activity was found in the right supramarginal gyrus right (R. Supramarginal g.) of the posterior parietal lobe (right; p < 0.01 corrected) as shown on a coronal (left). The activations are superimposed on a mean image of the participants’ structural scans. For illustrative purposes, we used p < 0.001 uncorrected and >5 voxels to threshold the statistical parametric maps. L, Left hemisphere; R, right hemisphere. The coordinate in standard space for the two slices is indicated. In the right panel, we plot the BOLD response in terms of the contrast estimates from the right supramarginal gyrus (R. SMG) for the two contrasts, (Change to heavier − No change heavy) and (Change to lighter − No change light). As can be seen, there is stronger activity during both types of lifts with unpredictable weight changes compared with the well programmed lifts. a.u., Arbitrary units.