Fig. 1.
Schematic representation of the experimental procedures (Experiment 1 and 2 in green and Experiment 3 in orange). (a) Experimental timelines. To activate the key regions involved in emotion regulation participants performed the social scenes task (localizer). Based on an individual’s localizer activity, we then defined three regions of interests (ROIs): left prefrontal cortex (PFC), left amygdala, left corticospinal tract (CST). Each NF run comprised fc-NF mini-blocks (20 volumes in Experiments 1 and 2; 40 volumes in Experiment 3) and no-NF mini-blocks (20 volumes), presented in alternating order. (b) Detailed view of the procedure during the NF task. NF was based on partial correlations rp between the PFC and amygdala activity, while controlling for CST ‘activity’, whereby partial correlations were obtained from a moving window comprising 20 subsequent volumes, which was updated with every incoming volume. Thus, for Experiments 1 and 2, the ratio of fc-NF: no-NF volumes in the correlation window is 1:19 at the first volume of the mini-block, 2:18 at the second volume of the mini-block and 20:0 at the last volume of the mini-block, and vice versa for no-NF mini-blocks. Note that due to the extended window length for the fc-NF mini-blocks in Experiment 3, the ratio of fc-NF: no-NF volumes in the correlation window is 20:0 for twenty volumes. Number of fc-NF volumes in the correlation window (N of fc-NF volumes in rp) is illustrated in form of a grey shape (c) Probabilistic maps of subject-specific ROIs (i.e. PFC and amygdala). superimposed on the groups’ average structural image in MNI space. The respective centre of the PFC probabilistic maps (Experiment 1 and 2: x = −20, y = 50, z = 24; Experiment 3: x = −26, y = 47, z = 22) are classified as Brodmann area 10 within the left middle frontal gyrus. The respective centre of the amygdala probabilistic maps (Experiment 1 and 2: x = −17, y = −1, z = −14; Experiment 3: x = −16, y = −3, z = −15) are classified as left amygdala (Eickhoff et al., 2005).