The dashed lines have slopes or 1.1, 1.0 and 0.9. The open symbols show the data from Table 2 of Jaric et al. Solid lines are linear regressions through the origin. Different symbols distinguish the three groups described above. A dashed line of unity slope through the origin defines the null-hypothesis.
Solid lines show linear regressions through the origin for each of the three conditions.
The null hypothesis is that expectation of load size has no effect on movement velocity. According to Jaric et al. The Table presents the results of analysis comparing each uncertain group to the known group using Student's t-test. In row 2 the actual load was greater than expected. In row 3 the actual load was less than expected.