Aftereffects of self-control exertion on brain activity in the right lateral prefrontal cortex.

<p>(a–c) More activity in participants suppressing emotions during the picture-viewing task relative to control participants was followed by relatively less activity during the Stroop task in a cluster located in the right middle frontal gyrus (BA 9), extending into the inferior frontal gyrus (BA 9/45). <i>t</i>-values of the interaction contrast are color coded and displayed at a threshold of <i>p</i> = .005 (uncorrected) superimposed on a coronal (a), axial (b) and sagittal (c) slice of an anatomical template image. (d) Parameter estimates (arbitrary units) of the averaged activity of the right lateral PFC cluster for the experimental groups. Parameter estimates are extracted as first eigenvariate of all activated voxels in the cluster. Means ± SE are indicated.</p

Bivariate correlations between Stroop interference effects and mean brain activity in the three regions of interest (ROI) during the Stroop task.

<p><i>Note</i>. *: significant after Bonferroni-Holm correction for multiple comparisons <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060385#pone.0060385-Holm1" target="_blank">[36]</a>. Stroop interference effects are calculated as errors on incongruent trials minus errors on congruent trials, residualized by average response latency. Brain activity during the Stroop task is calculated as the difference between incongruent vs. congruent trials. We extracted the parameter estimates for each subject for the left and right lateral PFC as well as the medial prefrontal ROI as first eigenvariate of all voxels in the respective ROI.</p

Regions of interest (ROI) used to identify effects of self-control exertion on prefrontal brain activity, superimposed on a coronal (a) or sagittal slice (b–c) of an anatomical template image.

<p>The three ROIs were functionally defined by the brain activation during the Stroop task (incongruent minus congruent trials; thresholded at <i>p = </i>.001, uncorrected, minimum cluster size k >28) in an independent sample of 19 healthy women who watched only neutral pictures before performing on the Stroop task. Blue: right lateral prefrontal cortex (lateral PFC); green: left lateral PFC; red: medial frontal cortex (MFC). (d) Overlap of activation during suppression of emotions during picture-viewing (yellow) with regions of interests obtained during the Stroop task (blue). Overlap is mainly observed in the right lateral prefrontal cortex and in the medial prefrontal cortex (red). Regions of activation are displayed with a minimum cluster size of k >28 at an individual voxel threshold of <i>p</i> = .001 in both analyses, superimposed on a coronal slice of an anatomical template image.</p

Results of the exploratory whole brain analysis for each task separately.

<p><i>Note.</i> BA: Brodmann area; R/L: right/left hemisphere; k_E: number of voxels; <i>Z</i>_max: Z-value at the peak activation of the cluster. Analysis thresholded at <i>p<</i>.001 (uncorrected) in a minimum of k_E >28 adjacent voxels. Cluster-level corrected <i>p</i>-values are indicated (*: <i>p</i><.05).</p

Overview of the experimental procedure and the behavioral results.

<p>(a) During the first task, the control group watched negative and neutral pictures. The suppression group suppressed emotions while watching the same pictures. Both groups subsequently completed a Stroop task. Brain imaging data was recorded during both tasks. (b) Participants in the emotion suppression group showed significantly stronger Stroop interference effects than participants in the control group. (Errors on incongruent minus errors on congruent trials.) Error bars represent standard errors of the mean (SE).</p

Results within the functionally defined prefrontal search volume for the interaction between activity during the picture-viewing and the Stroop task for different types of analyses.

<p><i>Note.</i> BA: Brodmann area; R/L: right/left hemisphere; k_E: number of voxels; <i>Z</i>_max: Z-value at the peak activation of the cluster. Analysis thresholded at <i>p<</i>.001 (uncorrected) inside the prefrontal ROI. Cluster-level corrected <i>p</i>-values are indicated (**: <i>p</i><.01). The search volume was functionally defined in an independent sample performing the Stroop task. It encompasses two activated clusters in the left and right lateral prefrontal cortices (including the inferior and middle frontal gyrus and the lateral precentral gyrus) as well as one activated cluster in the medial frontal cortex (supplementary motor area and superior frontal gyrus).</p

Age group dependence of mean FSFtot in Women (Fig 2a) and Men (Fig 2b) demonstrated in Box-and-Whisker plots.

<p>The line within the box represents the median value. Boxes represent 25^th to 75^th percentiles. The lines outside indicate the 10^th and 90^th percentiles.</p

Axial water-signal-only (left side) and fat-signal-only (right side) MR images in a 31-year-old woman.

<p>Regions of interest (ROIs) were placed in liver segments II, III, VI, VII and VIII on the water-signal-only images and copied to the fat-signal-only images.</p

Gender specific descriptive body characteristics of the study-group individuals.

<p>Abbreviations: WHR = waist-to-hip ratio, BMI = body mass index, BIA = body fat measured via fat analyzer</p><p>Gender specific descriptive body characteristics of the study-group individuals.</p

Group differences in resting-state regional cerebral blood flow (rCBF).

<p>R/L, left or right hemisphere; k<i>E</i>, cluster-size in voxels (one voxel is 2×2×2 mm); n.s., not significant; DID, patient group; SIM, DID simulating control group; DMPFC, dorsomedial prefrontal cortex.</p>a<p>MNI coordinates (in mm) refer to the maximum of signal change in each region.</p