Article Figures & Data
Figures
- Figure 1.
Task paradigm. ITI: inter-trial interval, CTI: cue-target interval.
- Figure 2.
ROIs locations. mPFC and LatOcc ROIs were obtained from the Desikan–Killiany atlas (caudal anterior cingulate and lateral occipital parcels, respectively). Hand ROIs were drawn with a 30-mm radius around the MNI motor areas hand coordinates ([±44, −17, 49]).
- Figure 3.
Behavioral results. Left panel, RTs (milliseconds). Right panel, Error rates. In each boxplot, the thick line inside box plots depicts the second quartile (median) of the distribution (n = 30). The bounds of the boxes depict the first and third quartiles of the distribution. Whiskers denote the 1.5 interquartile range of the lower and upper quartile. Dots represent individual subjects’ scores. Results for the 2 (Task) × 2 (Cued Side) × 2 (Response Side) rmANOVAs on RTs and error rates of regular trials are reported in Extended Data Figure 3-1.
- Figure 4.
Attentional contralateral alpha suppression. a, Time courses of the difference waves (contralateral vs ipsilateral) of α power from the LatOcc ROIs, time-locked to the onset of the retro-cue. Shading indicates the SEM, gray area refers to the extent of the significant cluster for the effect of Laterality (p < 0.001, cluster corrected). b, Source-reconstructed activity of the alpha power for the difference between contralateral and ipsilateral Cued Side, at 700 ms, for visualization purposes.
- Figure 5.
Motor contralateral beta suppression. a, Time courses of the difference waves (contralateral vs ipsilateral) of beta power from the Hand ROIs, time-locked to the onset of the retro-cue. Shading indicates the SEM, light gray area refers to the extent of the significant cluster for the effect of Laterality (p = 0.002, cluster corrected), dark gray area refers to the cluster for the interaction of Laterality and Task (p = 0.077, cluster corrected). b, Source-reconstructed activity of the beta power for the difference between contralateral and ipsilateral Response Side, at 1000 ms, for visualization purposes. au: arbitrary units.
- Figure 6.
Task-specific theta increase. a, Time courses of theta power from the mPFC ROIs, time-locked to the onset of the retro-cue. Shading indicates the SEM, gray area refers to the extent of the significant cluster for the effect of Task (p = 0.035, cluster corrected). Time courses of theta power time-locked to the retro-cue from Hand and LatOcc ROIs are reported in Extended Data Figure 6-1. b, Source-reconstructed activity of theta power for the difference between Implementation and Memorization, at 700 ms, for visualization purposes. au: arbitrary units.
- Figure 7.
Effect of mean theta power on RTs. a, Effect of theta power on RTs, for both Implementation and Memorization. High values of theta power are associated with faster RTs in both tasks. The interaction between theta power and Task was not significant. The dotted lines show the 95% confidence intervals. b, Mediation model with beta values. Task significantly influenced mPFC theta power, which in turns affected RTs. Therefore, theta power mediates the effect of tasks demands on behavioral performance. However, the direct effect of Task on RTs remained significant also when accounting for the mediating influence of theta power, suggesting a partial mediation. au: arbitrary units, asterisks denote the significance level (*p < 0.05, ***p < 0.001).
- Figure 8.
Connectivity between mPFC and posterior ROIs. LMMs revealed that Implementation task demands are associated with stronger connectivity in the theta frequency range between mPFC and motor regions (left panel) and visual regions (right panel). For visualization purposes, the plots depict subject-level averages. Blue and red curves represent the density distributions of subject-level averages of PLV of Implementation and Memorization, respectively. Light gray lines connect the average in the two Tasks for each individual participant, whereas the dark gray line connect the group-level averages (whiskers denote 95% confidence intervals). The same analysis performed on Parahippocampal ROIs as control regions and showing no difference across task demands is reported in Extended Data Figure 8-1. The same analyses performed computing the wPLI and confirming the pattern of results observed with PLV are reported in Extended Data Figure 8-2.
Extended Data
Extended Data Figure 3-1
Exploratory three-way ANOVAs on RTs (left panel) and Error rates (right panel). The exploratory three-way ANOVA on RTs confirmed the main effect of Task (F29,1 = 841.59, p < 0.001, η2p = 0.98) and additionally yielded significant effects of Response Side (F29,1 = 4.74, p = 0.038, η2p = 0.14) and the interaction of Cued * Response Side (F29,1 = 6.19, p = 0.019, η2p = 0.18). The corresponding ANOVA on Error Rates showed significant effects for Task (F29,1 = 13.36, p < 0.001, η2p = 0.31), Response Side (F29,1 = 5.64, p = 0.024, η2p = 0.16), the interaction of Cued * Response Side (F29,1 = 6.50, p = 0.016, η2p = 0.18), and the three-way interaction of Task * Cued Side * Response Side (F29,1 = 7.66, p = 0.010, η2p = 0.21). X-axis labels refer to the individual conditions resulting from the crossing of Cued Side and Response Side. The first letter indicates the cued hemispace (L for Left and R for right), the second letter denotes the instructed response hand (L for Left and R for Right). In each boxplot, the thick line inside box plots depicts the second quartile (median) of the distribution (n = 30). The bounds of the boxes depict the first and third quartiles of the distribution. Whiskers denote the 1.5 interquartile range of the lower and upper quartile. Dots represent individual subjects’ scores. Download Figure 3-1, TIF file.
Extended Data Figure 6-1
Theta power in LatOcc (left panel) and Hand (right panel) ROIs. To investigate to what extent our results might be affected by volume conduction, we compared theta power across tasks in the LatOcc and Hand ROIs. The aim of this control analysis was to check whether the task-specific increase in theta oscillations found in mPFC could be detected also from our other ROIs, namely Hand and LatOcc ROIs. To equate this analysis to the original one reported for mPFC, we used bilateral ROIs and compared theta power across tasks by means of a cluster-based permutation. No cluster was observed, supporting our claim that differences in connectivity between mPFC and posterior areas cannot be solely attributed to volume conduction from the former to the latter. The figure shows time courses of theta power, separately for each Task, time-locked to the onset of the retro-cue. Shading indicates the standard error of the mean (s.e.m). Download Figure 6-1, TIF file.
Extended Data Figure 8-1
Connectivity between mPFC and Parahippocampal ROIs. We investigated the connectivity patterns between mPFC and control areas, namely bilateral Parahippocampal ROIs. No task-related differences in synchronization between these regions were observed (F = 1.99, p = 0.17). This control analysis supports the assumption that mPFC selectively synchronizes the activity of task relevant areas, rather than producing a general effect across the whole brain. For visualization purposes, the figure depicts subject-level averages. Blue and red curves represent the density distributions of subject-level averages of PLV of Implementation and Memorization, respectively. Light gray lines connect the average in the two Tasks for each individual participant, whereas the dark gray line connect the group-level averages (whiskers denote 95% confidence intervals). Download Figure 8-1, TIF file.
Extended Data Figure 8-2
Connectivity between mPFC and posterior ROIs: wPLI. Connectivity analyses were additionally repeated using the weighted Phase-Lag Index (wPLI), a measure insensitive to volume conduction and source leakage issues, although more prone to false negatives in case of short delays between truly synchronized areas. wPLI values between mPFC and LatOcc ROIs are significantly larger during Implementation.The effect of task-demands in the synchronization between mPFC and Hand ROIs is significant with PLV, and only shows a trend towards significance for the wPLI. Given the higher spatial proximity of mPFC and Hand ROIs (as compared to mPFC and LatOcc ROIs), it is possible that the PLV between their signals is partially affected by volume conduction. At the same time, it is reasonable to speculate that true-connectivity would likely occur at a close-to-zero lag phase consistency, thus leading to the wPLI underestimating the existing phase synchronization However, the overall pattern of results with wPLI is consistent with the PLV, albeit less strong for the pair mPFC-Hand ROIs, and is in line with our hypothesis of stronger synchronization for Implementation task demands. The figure displays wPLI values between mPFC and motor regions (left panel) and visual regions (right panel); the plots depict subject-level averages. Blue and red curves represent the density distributions of subject-level averages of wPLI of Implementation and Memorization, respectively. Light gray lines connect the average in the two Tasks for each individual participant, whereas the dark gray line connect the group-level averages (whiskers denote 95% confidence intervals). Download Figure 8-2, TIF file.
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