Threat of shock increases excitability and connectivity of the intraparietal sulcus
- National Institute of Mental Health, National Institutes of Health, United States
Figures
Figure 1
Schematic of experimental paradigm.
(A) Subjects underwent alternating blocks of threat and safety. (B) Visual display present on the screen during the experiment. During the experiment subjects saw two circles. The color of the outer circle indicated the block type. The color of the inner circle was controlled by the subject, and reflected the subject’s then-current anxiety level.
Figure 2
Behavioral results from both experiments.
(A) Anxiety ratings during the MEG study. (B) Startle magnitude during the MEG study. (C) Anxiety ratings during the fMRI study. Bars represent the mean ± within-subject SEM (Cousineau, 2005). (D) Correlations between anxiety potentiated startle (APS) and differential anxiety ratings. The black squares represent the correlation between APS and ratings during the MEG session. The red dots represent the correlation between APS during the MEG study and anxiety ratings during the fMRI study in the subset of subjects who participated in both studies.
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Figure 2—source data 1
Source data for all graphs in Figure 2.
- https://doi.org/10.7554/eLife.23608.006
Figure 3
Overview of global brain connectivity (GBC) measure.
(A) Map showing average GBC across all safe and threat TRs. (B) Cartoon schematic of a correlation matrix. The 43204 voxel x 43204 voxel cross correlation matrix was calculated separately for each subject and each condition. Correlations were averaged across rows for the entire grey matter mask, to create a single map reflecting the average correlation between each voxel and all other voxels in the mask. (C) Graph representing the mean GBC following the Fisher’s Z transformation for safe and threat averaged across the entire grey matter mask. Bars represent the mean ± within-subject SEM (Cousineau, 2005).
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Figure 3—source data 1
Source data for graph in Figure 3C.
- https://doi.org/10.7554/eLife.23608.008
Figure 4
Results from voxelwise global brain connectivity (GBC) analysis.
(A) Statistical map showing results from a threat vs. safe paired-sample t-test. (B) Graph representing average GBC values after applying the Fisher’s Z transformation for clusters shown in panel A. Bars represent the mean ± within-subject SEM (Cousineau, 2005).
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Figure 4—source data 1
Source data for graph in Figure 4B.
- https://doi.org/10.7554/eLife.23608.011
Figure 5
Results from bilateral IPS seed-based connectivity analysis.
(A) Statistical map showing results from a threat vs. safe paired-sample t-test. (B) Graph representing average IPS connectivity values for clusters shown in panel A. Bars represent the mean ± within-subject SEM (Cousineau, 2005).
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Figure 5—source data 1
Source data for graph in Figure 5B.
- https://doi.org/10.7554/eLife.23608.014
Figure 6
Overview of MEG analyses.
(A) Spectrogram representing power averaged across all subjects and all sensors with peak in the alpha frequency band. (B) Graph showing the frequency of peak alpha (individual alpha frequency) averaged across subjects. Bars represent the mean ± SEM. (C) Example of single subject alignment with sensors (black dots) source grid (green dots) and headmodel (surface) plotted together.
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Figure 6—source data 1
Source data for graph in Figure 6A and B.
- https://doi.org/10.7554/eLife.23608.016
Figure 7
Alpha results from threat vs. safe t-test.
(A) Statistical map in sensor space showing a significant reduction in alpha power. Black symbols represent clusters of sensors showing significant threat vs. safe differences. (B) Graph showing average alpha power for safe and threat conditions in the largest cluster of sensors in panel A. (C) Statistical map in source space showing a significant reduction in alpha power. (D) Graph showing average alpha power for safe and threat conditions in the cluster in panel C. Bars represent the mean ± within-subject SEM (Cousineau, 2005).
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Figure 7—source data 1
Source data for graph in Figure 7B and D.
- https://doi.org/10.7554/eLife.23608.018
Figure 8
Conjunction map from voxelwise fMRI GBC analysis and MEG alpha power differences.
Colors represent significant safe vs. threat differences from the fMRI analysis (yellow), MEG analysis (blue), and both analyses (green).
Author response image 1
Author response image 2
Author response image 3
Author response image 4
Α connectivity across AAL regions during 2 second baseline prior to startle probe.
A) Mean α connectivity across AAL regions during safe periods. B) Mean α connectivity across AAL regions during threat periods. C) Unthresholded T-test results comparing α connectivity during safe and threat conditions. Thresholded T-test results comparing α connectivity during safe and threat conditions. Labels on Y-axis correspond to regions of the AAL axis. Labels on the X-axis correspond to groups from AAL atlas (frontal, limbic, occipital, parietal, subcortical, temporal, cerebellum). Boxes in A and B represent α connectivity in the occipital cortices.
Author response image 5
Β connectivity across AAL regions during 2 second baseline prior to startle probe.
A) Mean β connectivity across AAL regions during safe periods. B) Mean β connectivity across AAL regions during threat periods. C) Unthresholded T-test results comparing β connectivity during safe and threat conditions. Thresholded T-test results comparing β connectivity during safe and threat conditions. Labels on Y-axis correspond to regions of the AAL axis. Labels on the X-axis correspond to groups from AAL atlas (frontal, limbic, occipital, parietal, subcortical, temporal, cerebellum).
Author response image 6
Adjacency matrices constructed from downsampled timeseries for the α and β bands.
https://doi.org/10.7554/eLife.23608.027
Author response image 7
Adjacency matrices constructed from non-downsampled timeseries for the α and β bands.
https://doi.org/10.7554/eLife.23608.028
Author response image 8
Adjacency matrices constructed from downsampled timeseries that have been converted to z-scores for the α and β bands.
https://doi.org/10.7554/eLife.23608.029
Author response image 9
Adjacency matrices constructed from non-downsampled timeseries that have been converted to z-scores for the α and β bands.
https://doi.org/10.7554/eLife.23608.030Tables
Table 1
Individual differences for MEG (N = 28) and MRI (N = 25) experiments.
| Measure | MEG | MRI |
|---|---|---|
| STAI | ||
| State | 26.04 (1.37) | 23 (0.9) |
| Trait | 27.12 (0.93) | 28.18 (1.27) |
| ASI | 11.59 (1.21) | 8.64 (1.18) |
| BAI | 1.37 (0.42) | 0.58 (0.26) |
| BDI | 0.89 (0.32) | 0.42 (0.19) |
| Shock | ||
| Intensity (mA) | 5.66 (0.66) | 6.91 (1.01) |
| Rating | 8.51 (0.2) | 9.09 (0.19) |
| Anxiety | ||
| Pre | 2.04 (0.27) | 1.98 (0.25) |
| Safe | 2.47 (0.31) | 1.76 (0.21) |
| Threat | 5.41 (0.37) | 5.97 (0.39) |
| Fear | ||
| Pre | 1.41 (0.15) | 1.5 (0.23) |
| Safe | 1.84 (0.27) | 1.27 (0.12) |
| Threat | 4.44 (0.39) | 4.7 (0.42) |
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Note: Numbers reflect the mean and standard deviation of the results [M (SD)].
Table 2
Results from voxelwise GBC analysis.
| Label | Volume | t-value | Peak activation (LPI) | ||
|---|---|---|---|---|---|
| x | y | z | |||
| Right Angular Gyrus | 158 | 3.45 | 48 | −51 | 27 |
| Right Intraparietal Sulcus | 83 | 3.42 | 21 | −60 | 66 |
| Left Intraparietal Sulcus | 81 | 3.6 | −18 | −63 | 66 |
Table 3
Results from voxelwise IPS connectivity analysis.
| Label | Volume | t-value | Peak activation (LPI) | ||
|---|---|---|---|---|---|
| x | y | z | |||
| Left Thalamus | 342 | 3.92 | -9 | 6 | 12 |
| Right Inferior Parietal Lobule | 208 | 3.67 | 57 | −57 | 39 |
| Left Superior Medial Gyrus | 184 | 3.65 | 3 | 36 | 42 |
| Left Precuneus | 179 | 3.59 | 3 | −69 | 48 |
| Right Middle Frontal Gyrus | 137 | 3.64 | 33 | 15 | 60 |
| Left Angular Gyrus | 113 | 3.51 | −57 | −54 | 30 |
| Left Middle Frontal Gyrus | 96 | 3.69 | −24 | 15 | 60 |
| Left Middle Frontal Gyrus | 90 | 3.48 | −45 | 51 | -3 |
Additional files
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Source code 1
Code used to conduct Startle, MEG, and MRI analyses.
This zip file contains shell scripts and matlab functions that were used to analyze the Startle, MEG, and MRI data.
- https://doi.org/10.7554/eLife.23608.020
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Supplementary file 1
High resolution adjacency matrices for the MEG connectivity analyses.
This zip file contains high resolution images of the adjacency matrices for the MEG connectivity analysis suggested by the editor and reviewers.
- https://doi.org/10.7554/eLife.23608.021
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Threat of shock increases excitability and connectivity of the intraparietal sulcus
eLife 6:e23608.
https://doi.org/10.7554/eLife.23608
