Working Memory-Related Prefrontal Hemodynamic Responses in University Students: A Correlation Study of Subjective Well-Being and Lifestyle Habits

Figures

• 

  Figure 1. Participants included in the analysis of each task. The number of participants remaining in the final analysis for each channel in the verbal working memory (VWM) task (A) and spatial working memory (SWM) task (B). Each channel is indicated by a square with the channel number and the sample number in parentheses.

• 

  Figure 2. The sequence of working memory tasks and experimental procedure. For the VWM task (A), four Hiragana characters were presented as the target (S1) and a Katakana character was presented as the probe (query) stimulus (S2). For the SWM task (B), eight squares including four red squares were presented as the target (S1) and one red square and seven white squares were presented as the probe (query; S2). The experimental procedure is outlined in the aligned feathered arrow shapes (C). SUBI, Subjective Well-Being Inventory; NIRS, near-infrared spectroscopy.

• 

  Figure 3. Wearable NIRS device. The attached probe unit (a wearable package as a headset) can fully cover the forehead (A). In the probe unit, emitters and detectors are alternately arranged in two rows at an inter-probe distance of 30 mm (B). The center channel was placed on the Fpz point. Channels surrounded by dotted circles were excluded from analysis. Written informed consent was obtained from this individual (A) for publication of this image.

• 

  Figure 4. Grand average waveform of the task-related oxygenation process. Signal-averaging was applied to depict the task-related oxygenation response at each channel across all analyzed participants (A). In the oxygenation process at the representative channel (channel 8), double-headed arrows indicate the target stimulus (S1) period, activation period, and the probe (query) stimulus (S2) period (B). VWM, Verbal working memory; SWM, spatial working memory.

• 

  Figure 5. The significance of task-related prefrontal cortex (PFC) activation. Channels with significant task-related oxy-hemoglobin signal changes during the activation period at each channel across participants are illustrated by colored squares in the VWM task (A) and SWM task (B). The color spectrum bars at the right end indicate the t-value scale. Channels with statistical significance are indicated by asterisks (*q < 0.05, **q < 0.01).

• 

  Figure 6. VWM task-related oxy-hemoglobin signal changes and the SUBI positive affect score. Levels of correlation are illustrated by colored squares (A). The color spectrum bar indicates the r-value scale. Channels with statistical significance even after false discovery rate (FDR) correction are indicated by an asterisk (q < 0.05). Scatter plots with a regression line and 95% confidence interval represent the significant channels (B). Outliers are indicated in parentheses. VWM, Verbal working memory; SUBI, Subjective Well-Being Inventory; oxy-Hb, oxy-hemoglobin.

• 

  Figure 7. Verbal working memory task-related oxy-hemoglobin signal changes and the number of gaming days in 1 week. Levels of correlation are illustrated by colored squares (A). The color spectrum bar indicates the r-value scale. The channel with statistical significance even after FDR correction is indicated by an asterisk (q < 0.05). The scatter plot with a regression line and 95% confidence interval represents the significant channel (B). An outlier is indicated in parentheses. VWM, Verbal working memory; oxy-Hb, oxy-hemoglobin.

• 

  Figure 8. SWM task-related oxy-hemoglobin signal change and the number of gaming days in 1 week. Levels of correlation are illustrated by colored squares (A). The color spectrum bar indicates the r-value scale. The channel with statistical significance even after FDR correction is indicated by an asterisk (q < 0.05). The scatter plot with a regression line and 95% confidence interval represents the significant channel (B). SWM, Spatial working memory; oxy-Hb, oxy-hemoglobin.

• 

  Figure 9. SWM task-related oxy-hemoglobin signal changes and the number of drinking days in 1 week. Levels of correlation are illustrated by colored squares (A). The color spectrum bar indicates the r-value scale. Channels with statistical significance even after FDR correction are indicated by an asterisk (q < 0.05). Scatter plots with regression lines and 95% confidence intervals represent the significant channels (B). Outliers are indicated in parentheses. SWM, Spatial working memory; oxy-Hb, oxy-hemoglobin.