Figure 3
Grand average movement parameter auto-/cross-correlation curves, and movement parameter tuning curves. (a–d) Grand average stimuli auto- and cross-correlations. (a) Auto- and cross-correlation curves of horizontal components relative to the horizontal cursor position during execution (solid lines) and observation (dashed lines). Movement parameters are color-coded. Shaded areas represent the standard-error of the mean. Cross-correlations were evaluated for lags, ranging from −0.5 s (leading relative to cursor position) to 0.5 s (lagging) in 0.1 s steps. (b) Auto- and cross-correlation curves of horizontal components relative to the horizontal cursor velocity. (c), Auto- and cross-correlation curves of vertical components relative to the vertical target position. (d) Vertical target velocity. (e) Outline of the regression approach. After EEG preprocessing (including bandpass-filtering), a sliding window (one sample) was used to decode the movement parameters at different lags. (f–i) Grand average correlations between movement parameters and their estimates at different lags (tuning curves). (f) Tuning curves for the horizontal target position (blue) and velocity (orange). The mean and its standard error summarize the results for execution (solid lines), observation (dashed lines) and their paired difference (dash dotted lines). Cross-correlation peaks between target position and velocity were used to align the time-lag axes. Lags with significant differences between conditions (paired Wilcoxon sign-rank tests, FDR adjustment for 88 comparisons, 0.05 significance level) are highlighted (*). (g) Tuning curves for horizontal cursor position (violet) and velocity (green). (h) Tuning curves for vertical target position (blue) and velocity (orange). (i) Tuning curves for vertical cursor position (violet) and velocity (green).
