Resting heart rate variability modulates the effects of concurrent working memory load on affective startle...

Area of Science:

• Psychophysiology
• Neuroscience
• Emotion Regulation

Background:

• Vagally mediated heart rate variability (vmHRV) is theorized to represent top-down control in emotion regulation.
• The Generalized Unsafety Theory of Stress (GUTS) posits that vmHRV reflects resources for inhibiting threat responses.
• Previous research linked vmHRV to affective startle modification, but the mediating role of top-down resources was unclear.

Purpose of the Study:

• To directly test if top-down resources mediate the relationship between vmHRV and context-appropriate affective responding.
• To investigate the impact of working memory (WM) load on affective responses in relation to vmHRV.

Main Methods:

• 92 college-aged participants completed a picture viewing task with concurrent working memory (WM) load.
• Affective startle (SR) response was measured during picture viewing under manipulated WM load.
• Electrocardiography and electromyography were used to assess vmHRV and SR eyeblink.

Main Results:

• Increased WM load attenuated affective SR modification.
• This attentuation effect was more pronounced in individuals with lower vmHRV compared to those with higher vmHRV.
• Findings suggest vmHRV is linked to context-appropriate affective responding via top-down resources.

Conclusions:

• Results support the GUTS theory by demonstrating vmHRV's role in top-down regulation of affective responses.
• Low vmHRV may be associated with atypical affective responding due to insufficient working memory resources.
• The study highlights the connection between vmHRV, top-down resources, and emotion regulation, offering insights into emotion dysregulation in psychopathology.