Sleep dependent autonomic correlates of affect and arousal in younger and older adults

Figures

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  Figure 1. (A) Experimental timeline. Participants completed baseline emotional ratings at 10:00 a.m., followed by a 90-minute nap opportunity at 1:30 p.m. post-nap emotional ratings were obtained at 3:30 p.m. to assess changes in affect following sleep. (1B) Arousal–valence affect categories. Emotional ratings were organized into four categories based on arousal (low to high) and valence (positive to negative): High-arousal positive (joyful, happy), low-arousal positive (pleased), high-arousal negative (angry, anxious), and low-arousal negative (depressed, unhappy, frustrated).

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  Figure 2. (A) Mean post nap positivity ratings for high and low arousal emotions in younger and older adults. Positivity ratings represent the difference between positive and negative affect ratings within each arousal level (low vs. high), with higher values indicating greater positive than negative affect endorsement. Bars depict mean ratings for younger (orange) and older (blue) adults in each condition. Younger adults exhibited significantly greater positivity ratings for low arousal compared to high arousal emotions following the nap, whereas older adults did not show a significant difference between arousal conditions. Error bars represent ± SE. p < .01.

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  Figure 3. (A) Associations between autonomic activity during NREM sleep and post-sleep low-arousal positivity ratings. lnHF during NREM sleep. Higher lnHF during NREM was associated with lower post-nap low-arousal positivity ratings. (3B) lnLF during stage NREM sleep. Higher lnLF during NREM was associated with higher post-nap low-arousal positivity ratings. Lines represent marginal predictions from linear regression models relating sleep physiological variables (lnHF and lnLF) to post-nap low-arousal positivity ratings while holding other covariates constant at their mean values. Shaded areas indicate 95% confidence intervals. Points represent individual participants and are color-coded by age group (young adults: Orange circles; older adults: Blue triangles).

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  Figure 4. Associations between sleep physiological activity during NREM sleep and post-sleep high-arousal positivity ratings. Higher lnHF during NREM was associated with lower post-nap high-arousal positivity ratings. Lines represent marginal predictions from linear regression models relating sleep physiological variables to post-nap high-arousal positivity ratings while holding other covariates constant at their mean values. Shaded areas indicate 95% confidence intervals. Points represent individual participants and are colored by age group (young adults, orange circles; older adults, blue triangles).