The two-way interaction of task and period (iii, iv) was highly significant in the stimulus-offset condition, F (1,12) = 12.4, P < .01, η 2 p = .51, but not in the stimulus-maintenance condition, F (1,13) = 2.3, P = .15, η 2 p = .15.
There was a marginally significant contrast for the interaction of task and periods i and ii, F (1,25) = 4.0, P = .06, η 2 p = .14, indicating a steeper decline in mu power from period i to ii during the report-grasp task (from 4.75 μV 2 to 3.01 μV 2 ) than during the report-colour task (from 4.41 μV 2 to 3.12 μV 2 ).