Figure 3
ROI timecourses extracted from PMd (A,C) and SPL (B,D), comparing the fMRI-signal in the delayed reach task of Experiments 1 and 2 (A,B vs. C,D, respectively). Cyan-shaded areas represent time epochs during which paired t-test comparisons of signal amplitudes between “NEAR” and “FAR” reaches revealed statistically significant differences (p < 0.05) for at least three neighboring time-points. Such differences were considered indicative of an influence of trajectory. PMd shows different planning-related signal amplitudes in both experiments (leftward part of the panels A and C, aligned to CUE onset). SPL shows trajectory planning signal modulation in Experiment 2 only (D). PMd shows significant modulation in the reach phase in both experiments (A and C, right panels, aligned to REACH onset), whereas SPL shows such statistically significant difference only in Experiment 2 (D) although a hint of the same effect might be present in the reach phase of Experiment 1 as well (B). Dotted gray boxes indicate the late delay phase, in which activity merely represents planning but no longer CUE-related activity. Activity estimates of this period were also used for a subsequent statistical comparison between PMd and SPL across experiments (see RESULTS).
