diff --git a/analysis/matlab/variations/unmerge_d0_13/learning_curve.png b/analysis/matlab/variations/unmerge_d0_13/learning_curve.png
index 6f6b35c..9a1cd74 100644
Binary files a/analysis/matlab/variations/unmerge_d0_13/learning_curve.png and b/analysis/matlab/variations/unmerge_d0_13/learning_curve.png differ
diff --git a/analysis/matlab/variations/unmerge_d0_13/learning_curve_rate.png b/analysis/matlab/variations/unmerge_d0_13/learning_curve_rate.png
index 5c6cd0f..c77f4c3 100644
Binary files a/analysis/matlab/variations/unmerge_d0_13/learning_curve_rate.png and b/analysis/matlab/variations/unmerge_d0_13/learning_curve_rate.png differ
diff --git a/analysis/matlab/variations/unmerge_d0_13/plotcurve.m b/analysis/matlab/variations/unmerge_d0_13/plotcurve.m
index 193a44b..8fb7f44 100644
--- a/analysis/matlab/variations/unmerge_d0_13/plotcurve.m
+++ b/analysis/matlab/variations/unmerge_d0_13/plotcurve.m
@@ -38,8 +38,9 @@ legend([e1 e2], {sprintf('anodal, N = %d', na), sprintf('control, N = %d', nc)},
     'Location', 'northwest', 'Box', 'off');
 xlabel('training day'); ylabel(ylab);
 title(vname, 'Interpreter', 'none');
-set(gca, 'XTick', xd, 'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
-xtickangle(90);                  % vertical x-axis tick labels
+set(gca, 'XTick', xd, 'XTickLabelRotation', 90, ...   % vertical x-axis tick labels
+    'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
+drawnow;                         % force layout so the rotation is applied headless
 exportgraphics(fig, outFile, 'Resolution', 150);
 close(fig);
 fprintf('%s: wrote %s (anodal N=%d, control N=%d)\n', vname, outFile, na, nc);
diff --git a/analysis/matlab/variations/unmerge_d0_5/learning_curve.png b/analysis/matlab/variations/unmerge_d0_5/learning_curve.png
index 270abdc..71777f7 100644
Binary files a/analysis/matlab/variations/unmerge_d0_5/learning_curve.png and b/analysis/matlab/variations/unmerge_d0_5/learning_curve.png differ
diff --git a/analysis/matlab/variations/unmerge_d0_5/learning_curve_rate.png b/analysis/matlab/variations/unmerge_d0_5/learning_curve_rate.png
index be1356c..23bcdaf 100644
Binary files a/analysis/matlab/variations/unmerge_d0_5/learning_curve_rate.png and b/analysis/matlab/variations/unmerge_d0_5/learning_curve_rate.png differ
diff --git a/analysis/matlab/variations/unmerge_d0_5/plotcurve.m b/analysis/matlab/variations/unmerge_d0_5/plotcurve.m
index 193a44b..8fb7f44 100644
--- a/analysis/matlab/variations/unmerge_d0_5/plotcurve.m
+++ b/analysis/matlab/variations/unmerge_d0_5/plotcurve.m
@@ -38,8 +38,9 @@ legend([e1 e2], {sprintf('anodal, N = %d', na), sprintf('control, N = %d', nc)},
     'Location', 'northwest', 'Box', 'off');
 xlabel('training day'); ylabel(ylab);
 title(vname, 'Interpreter', 'none');
-set(gca, 'XTick', xd, 'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
-xtickangle(90);                  % vertical x-axis tick labels
+set(gca, 'XTick', xd, 'XTickLabelRotation', 90, ...   % vertical x-axis tick labels
+    'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
+drawnow;                         % force layout so the rotation is applied headless
 exportgraphics(fig, outFile, 'Resolution', 150);
 close(fig);
 fprintf('%s: wrote %s (anodal N=%d, control N=%d)\n', vname, outFile, na, nc);
diff --git a/analysis/matlab/variations/unmerge_d6_10/learning_curve.png b/analysis/matlab/variations/unmerge_d6_10/learning_curve.png
index ceb59d3..561cf02 100644
Binary files a/analysis/matlab/variations/unmerge_d6_10/learning_curve.png and b/analysis/matlab/variations/unmerge_d6_10/learning_curve.png differ
diff --git a/analysis/matlab/variations/unmerge_d6_10/learning_curve_rate.png b/analysis/matlab/variations/unmerge_d6_10/learning_curve_rate.png
index 481dddd..d0df499 100644
Binary files a/analysis/matlab/variations/unmerge_d6_10/learning_curve_rate.png and b/analysis/matlab/variations/unmerge_d6_10/learning_curve_rate.png differ
diff --git a/analysis/matlab/variations/unmerge_d6_10/plotcurve.m b/analysis/matlab/variations/unmerge_d6_10/plotcurve.m
index 193a44b..8fb7f44 100644
--- a/analysis/matlab/variations/unmerge_d6_10/plotcurve.m
+++ b/analysis/matlab/variations/unmerge_d6_10/plotcurve.m
@@ -38,8 +38,9 @@ legend([e1 e2], {sprintf('anodal, N = %d', na), sprintf('control, N = %d', nc)},
     'Location', 'northwest', 'Box', 'off');
 xlabel('training day'); ylabel(ylab);
 title(vname, 'Interpreter', 'none');
-set(gca, 'XTick', xd, 'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
-xtickangle(90);                  % vertical x-axis tick labels
+set(gca, 'XTick', xd, 'XTickLabelRotation', 90, ...   % vertical x-axis tick labels
+    'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
+drawnow;                         % force layout so the rotation is applied headless
 exportgraphics(fig, outFile, 'Resolution', 150);
 close(fig);
 fprintf('%s: wrote %s (anodal N=%d, control N=%d)\n', vname, outFile, na, nc);
diff --git a/analysis/matlab/variations/unmerge_d6_13/learning_curve.png b/analysis/matlab/variations/unmerge_d6_13/learning_curve.png
index 74f844d..310be29 100644
Binary files a/analysis/matlab/variations/unmerge_d6_13/learning_curve.png and b/analysis/matlab/variations/unmerge_d6_13/learning_curve.png differ
diff --git a/analysis/matlab/variations/unmerge_d6_13/learning_curve_rate.png b/analysis/matlab/variations/unmerge_d6_13/learning_curve_rate.png
index 41f75d7..558ce66 100644
Binary files a/analysis/matlab/variations/unmerge_d6_13/learning_curve_rate.png and b/analysis/matlab/variations/unmerge_d6_13/learning_curve_rate.png differ
diff --git a/analysis/matlab/variations/unmerge_d6_13/plotcurve.m b/analysis/matlab/variations/unmerge_d6_13/plotcurve.m
index 193a44b..8fb7f44 100644
--- a/analysis/matlab/variations/unmerge_d6_13/plotcurve.m
+++ b/analysis/matlab/variations/unmerge_d6_13/plotcurve.m
@@ -38,8 +38,9 @@ legend([e1 e2], {sprintf('anodal, N = %d', na), sprintf('control, N = %d', nc)},
     'Location', 'northwest', 'Box', 'off');
 xlabel('training day'); ylabel(ylab);
 title(vname, 'Interpreter', 'none');
-set(gca, 'XTick', xd, 'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
-xtickangle(90);                  % vertical x-axis tick labels
+set(gca, 'XTick', xd, 'XTickLabelRotation', 90, ...   % vertical x-axis tick labels
+    'FontName', 'Arial', 'FontSize', 13, 'LineWidth', 1.5, 'Box', 'off');
+drawnow;                         % force layout so the rotation is applied headless
 exportgraphics(fig, outFile, 'Resolution', 150);
 close(fig);
 fprintf('%s: wrote %s (anodal N=%d, control N=%d)\n', vname, outFile, na, nc);