Gender-related effects of prefrontal cortex connectivity: a resting-state functional optical tomography study.

This figure consists of a 3D anatomical model of a head (top left) and a 2D schematic diagram (bottom) illustrating the localization of 52 fOT channels. The schematic uses red circles for light sources and blue circles for detectors, with yellow diamonds marking the measuring regions of the prefrontal cortex. Positions are mapped according to the international 10-20 system, with specific markers labeled as $F_Z$, $F_{P1}$, $F_{P2}$, $T_3$, and $T_4$, and a grid spacing of 3 cm indicated.

This figure is a multi-panel flowchart illustrating the resting-state fOT data analysis pipeline. It includes anatomical diagrams of channel localization (a), a power spectrum plot (b), a group-level spectrogram (c), and time-series data (e) for $\Delta\text{HbO}_2$, $\Delta\text{Hb}$, and $\Delta\text{tHb}$. The workflow concludes with schematic representations of group average correlation matrices (f), cortical lateralization (g), functional connectivity in the PFC (h), and correlation coefficients between the left and right PFC (i).

This figure consists of six correlation matrices (heatmaps) comparing functional connectivity across 52 channels for male (a-c) and female (d-f) groups. The matrices are categorized by hemodynamic measures: $\Delta\text{HbO}_2$, $\Delta\text{Hb}$, and $\Delta\text{tHb}$. A color scale on the right indicates correlation strength, ranging from approximately -0.2 (blue) to 1 (red), with the diagonal showing perfect positive correlation.

This figure consists of three scatter plots (a, b, and c) comparing the correlation coefficients of male and female groups for $\Delta\text{HbO}_2$, $\Delta\text{Hb}$, and $\Delta\text{tHb}$, respectively. Each plot features a red linear regression line showing a positive correlation between the male and female groups. The strength of these correlations varies by channel, with $R^2$ values of 0.6342 for $\Delta\text{HbO}_2$, 0.3038 for $\Delta\text{Hb}$, and 0.6182 for $\Delta\text{tHb}$.

This figure presents six heatmaps showing the correlation of hemodynamic responses between bilateral prefrontal cortex (PFC) regions for male (a, c, e) and female (b, d, f) groups. The maps analyze three variables: $\Delta\text{HbO}_2$, $\Delta\text{Hb}$, and $\Delta\text{tHb}$, with background colors representing mean concentration changes and overlaid shaded diamonds indicating correlation values based on a provided coding scheme. Correlation strength is categorized from $<0.2$ (lightest) to $>0.8$ (black), with the right and left PFC regions labeled across the horizontal axis.

This figure consists of two brain diagrams, (a) for the male group and (b) for the female group, illustrating functional connectivity patterns in the prefrontal cortex (PFC). Red dots represent channels within the left and right PFC regions, while orange lines indicate group-level correlations with a coefficient $r_{XY} > 0.6$. Both groups show dense inter- and intra-hemispheric connectivity networks across the PFC regions.

This figure consists of two brain diagrams, (a) for males and (b) for females, illustrating cortical dominance in the prefrontal cortex (PFC) region. Blue diamonds indicate channels with leftward or rightward dominance, while non-shaded diamonds represent bilateral dominance. Both groups show a distribution of dominant channels across the left and right hemispheres, with slight variations in the specific channels highlighted between males and females.

This figure presents spectrograms of $\Delta$tHb for male (a) and female (b) groups, with the y-axis representing channels (1–50) and the x-axis representing frequency (Hz). A color bar indicates intensity, showing higher concentrations of signal in the lower frequency range (0.01 to 0.08 Hz) across various channels. Each group includes a zoomed-in bottom panel highlighting specific PFC region channels within that 0.01 to 0.08 Hz frequency range.

This figure is a schematic diagram of a brain showing the distribution of electrode channels across the prefrontal cortex (PFC). Specific channels are highlighted in orange to indicate significant differences (p < 0.001) between male and female groups based on power spectrum analysis. The highlighted channels include 7, 8, 19, 29, 30, 38, and 39 in the left PFC, and 13, 23, 34, and 45 in the right PFC.