The Redistribution of Power: Neurocardiac Signaling, Alcohol and Gender

Human adaptability involves interconnected biological and psychological control processes that determine how successful we are in meeting internal and environmental challenges. Heart rate variability (HRV), the variability in consecutive R-wave to R-wave intervals (RRI) of the electrocardiogram, captures synergy between the brain and cardiovascular control systems that modulate adaptive responding. Here we introduce a qualitatively new dimension of adaptive change in HRV quantified as a redistribution of spectral power by applying the Wasserstein distance with exponent 1 metric (W1) to RRI spectral data. We further derived a new index, D, to specify the direction of spectral redistribution and clarify physiological interpretation. We examined gender differences in real time RRI spectral power response to alcohol, placebo and visual cue challenges. Adaptive changes were observed as changes in power of the various spectral frequency bands (i.e., standard frequency domain HRV indices) and, during both placebo and alcohol intoxication challenges, as changes in the structure (shape) of the RRI spectrum, with a redistribution towards lower frequency oscillations. The overall conclusions from the present study are that the RRI spectrum is capable of a fluid and highly flexible response, even when oscillations (and thus activity at the sinoatrial node) are pharmacologically suppressed, and that low frequency oscillations serve a crucial but less studied role in physical and mental health

Rest, Reactivity, and Recovery: A Psychophysiological Assessment of Borderline Personality Disorder

Difficulty regulating emotion is a cardinal feature of borderline personality disorder (BPD), yet little is known about the automatic psychophysiological processes involved in this phenotype. Inconsistent findings have emerged from studies that employed limited assessments (e.g., heart rate variability, skin conductance) of autonomic nervous system response to emotional contexts, and compared groups based on the presence or absence of BPD as a categorical diagnosis. This exploratory study assessed a comprehensive set of autonomic nervous system processes in 44 individuals (22 with BPD) at rest, in response to emotionally evocative stimuli, and during a subsequent recovery period. BPD was characterized with a dimensional measure of BPD symptom severity, as a well by categorical diagnosis. At baseline and across experimental tasks, higher heart rate was observed in those diagnosed with BPD compared to controls, and in those expressing greater BPD symptom severity. These effects, however, were fully mediated by differences in physical exercise. In contrast, during recovery from emotional activation, greater symptom severity predicted consistently higher levels of multiple sympathetic and parasympathetic processes compared to lower symptom severity. Overall, these findings suggest that the heart rate elevations sometimes observed in those diagnosed with BPD may be associated with individual and group differences in levels of physical exercise. Results further indicate that adaptive psychophysiological recovery responses following emotional challenge may be disrupted in proportion to BPD symptom severity, independently of exercise. Results highlight the utility of considering lifestyle factors and symptom severity in studies of emotional activation and regulation processes in BPD

Directionality of redistribution differed between men and women.

<p>Spectral power showed little redistribution during the control beverage condition (n = 55 females, 54 males) in response to the post-drinking baseline (B2) and the neutral (Nt), negative (Ng), and positive (Ps) visual cue tasks. Spectral power redistributed towards lower frequencies in the placebo (n = 55 females, 54 males) and alcohol (n = 88 females, 84 males) beverage conditions in response to positive and negative visual cues, more so in women than men (* = p<.05).</p

Mean change from pre-drinking baseline in the logarithm of high frequency (HF) heart rate variability (HRV) differed in men and women during intoxication.

<p>Suppression of HF HRV (i.e., spectral power in the HF range) by alcohol (n = 88 females, 84 males) was noted during the post-drinking baseline (B2), and the neutral (Nt) and negative (Ng) visual cue tasks. This suppression was generally greater in men than women (* = p<.05). No gender differences were noted in the control (n = 55 females, 54 males) or placebo (n = 55 females, 54 males) beverage conditions.</p

Mean change from pre-drinking baseline in the logarithm of low frequency (LF) heart rate variability (HRV) differed between men and women.

<p>Changes in LF HRV (i.e., spectral power in the LF range) were noted during the post-drinking baseline (B2) and the neutral (Nt), negative (Ng), and positive (Ps) visual cue tasks. Changes were observed in the control (n = 55 females, 54 males), placebo (n = 55 females, 54 males), and alcohol (n = 88 females, 84 males) beverage conditions (* = p<.05, men versus women).</p

Mean W₁ index differed for men and women.

<p>Redistribution of spectral power was observed during the control (n = 55 females, 54 males), placebo (n = 55 females, 54 males), and alcohol (n = 88 females, 84 males) beverage conditions in response to a post-drinking baseline (B2) and while viewing neutral (Nt), negative (Ng), and positive (Ps) visual cues. Women, compared to men, demonstrated a significantly greater redistribution in response to a post-drinking baseline and all visual cue stimulations during alcohol and placebo challenges (* = p<.05).</p

Mean change from pre-drinking baseline in the low frequency (LF)/high frequency (HF) ratio differed between men and women.

<p>Changes in the LF/HF HRV ratio were noted during the post-drinking baseline (B2) and the neutral (Nt), negative (Ng), and positive (Ps) visual cue tasks. Changes were observed in the control (n = 55 females, 54 males) and placebo (n = 55 females, 54 males) beverage conditions, but not in the alcohol condition (* = p<.05, men versus women).</p