Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Intracranial eLORETA alpha (8Hz-13Hz) current density across the brain. Current density was normalized (current density for a voxel divided by the summed current density across all voxels) and then log-transformed. Cooler colors (i.e., blue) indicate more alpha power and less activity. Hotter colors (orange and yellow) indicate less alpha power and more activity. Parietal-occipital regions showed the greatest alpha power. Anterior medial regions were characterized by less alpha power and more activity at rest.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Transformation Assay, Activity Assay

Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Intraclass correlation coefficients (ICCs) for various intracranial metrics. ICCs indicate the stability of intracranial source estimates across the eight EEG recordings collected in this study (four recording days, two recordings each day). Excellent reliability is colored green and includes coefficients greater than .75. Good reliability is colored blue and includes coefficients greater than .6 and less than .75. Fair reliability is colored pink or blue and includes coefficients greater than .4 and less than .6. Poor reliability is colored red and includes coefficients less than .4. Regions of dorsal-lateral, dorsal-medial, and polar PFC showed the lowest reliability, and these regions may be prone to state-like fluctuations in activity given their roles in on-demand executive functioning, working memory, and cortical organization. Top panel: ICCs for voxelwise eLORETA power estimates. Second from top panel: ICCs for eLORETA power estimates after averaging across 84 Brodmann areas. Second from bottom panel: ICCs for voxelwise intracranial asymmetry metric (LN[Right Voxel] – LN[Left Voxel]). White medial areas did not have asymmetry scores because of the asymmetrical eLORETA brain, nor was reliability computed. Bottom panel: ICCs for intracranial asymmetry metric for 84 Brodmann areas. Only the left hemisphere is displayed/colored for asymmetry scores (bottom two rows: left sagittal view and left medial view) because there is only one value for each pair of homologous left and right voxels. Bottom-right top panel: Histogram showing probability of ICC values for voxelwise eLORETA estimates and for eLORETA estimates after averaging within a Brodmann area. Bottom-right lower panel: Histogram showing probability of ICC values for voxelwise intracranial asymmetry scores and for average intracranial asymmetry scores within a Brodmann area.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Activity Assay

Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Correlations between surface asymmetry scores and intracranial asymmetry scores. Positive correlations (red voxels) indicate regions where more relative left activity at the surface was associated with more relative left intracranial activity. Only the left hemisphere is displayed/colored because these were asymmetry scores; thus, there is only one value for each pair of homologous left and right voxels. First column: left sagittal view. Second column: left medial view. Third column: bilateral ventral view (right hemisphere is displayed, but only left hemisphere is displaying correlation coefficients). Fourth column: left sagittal view with translucent scalp overlaid to show electrode positions relative to sources. Only correlations (r) greater than ± .3 are displayed.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Activity Assay

Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Intracranial asymmetry scores for MDD groups and healthy controls. Blue voxels indicate regions where MDD groups had smaller intracranial asymmetry scores (less relative left activity) than healthy controls. Participants with any lifetime MDD history (past or present) were characterized by less relative left mid-frontal activity compared to healthy controls. Top panel displays relationship between intracranial asymmetry after multiple comparisons correction, and bottom panel displays relationship between intracranial asymmetry with no multiple comparisons correction. Only the left hemisphere is displayed because these were asymmetry scores, and thus there is only one value for each pair of homologous left and right voxels. Top and left panels show left sagittal view. Bottom-right panel shows left medial view.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Activity Assay

Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Note. Interaction between group (e.g., MDD history) and hemisphere for voxels identified as significant from intracranial asymmetry analyses (left and right hemisphere voxels used for interaction are shown in black in upper right panel). Participants with any history of depression (blue line) were characterized by more alpha power in left hemisphere motor and premotor voxels than control participants (red line). There was no difference in alpha power for right-hemisphere voxels. Upper right inset shows voxels used for analysis. Results indicate that MDD risk may be characterized by less left frontal activity. Bars indicate standard errors of the mean.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Control, Activity Assay

Journal: Psychophysiology

Article Title: Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

doi: 10.1111/psyp.13019

Figure Lengend Snippet: Intracranial asymmetry scores for MDD groups and healthy controls presented along with regions identified as predictive of surface asymmetry. Light blue voxels indicate regions where MDD groups had smaller intracranial asymmetry scores (less relative left activity) than healthy controls. Red voxels indicate regions that correlated (r greater than ±.3) with surface asymmetry scores. Dark blue voxels were related to both surface asymmetry and lifetime depression history. Only the left hemisphere is displayed because these were intracranial asymmetry scores, and thus there is only one value for each pair of homologous left and right voxels.

Article Snippet: Contiguous voxels (6-way connectivity using the bwconncomp Matlab function) that were significant at p < .05 were treated as a cluster.

Techniques: Activity Assay