(A) The experimental sequence comprised a T1-weighted structural scan (8 min, grey), BOLD (6 min, orange) and ASL (6 min, green) at rest. This was followed by task-specific PET/MR acquisition. …
Task-specific changes of different metabolic demands as obtained with functional PET (fPET), blood oxygen level dependent (BOLD) signal and arterial spin labeling (ASL, all pFWE < 0.05 corrected …
Task-induced changes CMRGlu, CBF and BOLD signal.
To compute task-specific CMRGlu estimates independent of BOLD changes, fPET was also calculated using a method previously developed by our group (Hahn et al., 2016). In this method, the baseline …
MCM was calculated as correlation between glucose metabolism and functional connectivity across all subjects (z-transformed Pearson’s r values). The small circles in the plots show z-scores of …
Metabolic connectivity mapping data.
Similar to MCM, also functional connectivity was sensitive to task performance and showed significant increases from rest to task for all three connections. As functional connectivity by definition …
Functional connectivity data.
It has been suggested that the order of common preprocessing steps may impact the estimates of functional connectivity, especially when performing motion scrubbing (Carp, 2013). To directly test …
Metabolic connectivity mapping data with alternative functional connectivity preprocessing.
Unsmoothed data on functional connectivity and CMRGlu were separately permuted across voxels, yielding MCM values tightly centered on zero (blue bars, z = 0.00005 ± 0.004). Spatial smoothing still …
Unsmoothed random permutation MCM data for IPS -> Occ.
Smoothed random permutation data for IPS -> Occ.
Unsmoothed random permutation MCM data for FEF -> Occ.
Smoothed random permutation MCM data for FEF -> Occ.
Inference across the entire model space indicates the highest probability for the first model, which corresponds to the model resulting from the MCM analysis (Figure 3). Testing each task modulation …
Probability of DCM models.
Probability of DCM family inference.
BOLD time series were extracted from spheres of 5 mm radius, each individually shifted to the location with the maximum effect size in the analysis of task changes (F-test) and constrained by the …
For the effective connections Occ –> IPS, Occ -> FEF and FEF –> IPS the relevance of task modulation was tested, whereas for the connection IPS -> FEF the relevance of the intrinsic connection was …
Similar to the results from the original analysis (Figure 4), model one showed the highest posterior probability and family inference indicated high probabilities for all four connections.
Probability of DCM models with 8 mm smoothing.
Probability of DCM family inference with 8 mm smoothing.