Stefan Sütterlin

ARTiiFACT: a tool for heart rate artifact processing and heart rate variability analysis.

The importance of appropriate handling of artifacts in interbeat interval (IBI) data must not be underestimated. Even a single artifact may cause unreliable heart rate variability (HRV) results. Thus, a robust artifact detection algorithm and the option for manual intervention by the researcher form key components for confident HRV analysis. Here, we present ARTiiFACT, a software tool for processing electrocardiogram and IBI data. Both automated and manual artifact detection and correction are available in a graphical user interface. In addition, ARTiiFACT includes time- and frequency-based HRV analyses and descriptive statistics, thus offering the basic tools for HRV analysis. Notably, all program steps can be executed separately and allow for data export, thus offering high flexibility and interoperability with a whole range of applications.

Affective Instability in Daily Life Is Predicted by Resting Heart Rate Variability

Previous research has shown that being affectively unstable is an indicator of several forms of psychological maladjustment. However, little is known about the mechanisms underlying affective instability. Our research aims to examine the possibility that being prone to extreme fluctuations in one’s feelings is related to maladaptive emotion regulation. We investigated this hypothesis by relating affective instability, assessed in daily life using the experience sampling method, to self-reported emotion regulation strategies and to parasympathetically mediated heart rate variability (HRV), a physiological indicator of emotion regulation capacity. Results showed that HRV was negatively related to instability of positive affect (as measured by mean square successive differences), indicating that individuals with lower parasympathetic tone are emotionally less stable, particularly for positive affect.

Cold pressor stress induces opposite effects on cardioceptive accuracy dependent on assessment paradigm.

Interoception depends on visceral afferent neurotraffic and central control processes. Physiological arousal and organ activation provide the biochemical and mechanical basis for visceral afferent neurotraffic. Perception of visceral symptoms occurs when attention is directed toward body sensations. Clinical studies suggest that stress contributes to the generation of visceral symptoms. However, during stress exposure attention is normally shifted away from bodily signals. Therefore, the net effects of stress on interoception remain unclear. We, therefore, investigated the impact of the cold pressor test or a control intervention (each n=21) on three established laboratory paradigms to assess cardioceptive accuracy (CA): for the Schandry-paradigm, participants were asked to count heartbeats, while during the Whitehead-tasks subjects were asked to rate whether a cardiac sensation appeared simultaneously with an auditory or visual stimulus. CA was increased by stress when attention was focused on visceral sensations (Schandry), while it decreased when attention was additionally directed toward external stimuli (visual Whitehead). Explanations for these results are offered in terms of internal versus external deployment of attention, as well as specific effects of the cold pressor on the cardiovascular system.

Rumination and Age: Some Things Get Better

Rumination has been defined as a mode of responding to distress that involves passively focusing ones attention on symptoms of distress without taking action. This dysfunctional response style intensifies depressed mood, impairs interpersonal problem solving, and leads to more pessimistic future perspectives and less social support. As most of these results were obtained from younger people, it remains unclear how age affects ruminative thinking. Three hundred members of the general public ranging in age from 15 to 87 years were asked about their ruminative styles using the Response Styles Questionnaire (RSQ), depression and satisfaction with life. A Mokken Scale analysis confirmed the two-factor structure of the RSQ with brooding and reflective pondering as subcomponents of rumination. Older participants (63 years and older) reported less ruminative thinking than other age groups. Life satisfaction was associated with brooding and highest for the earlier and latest life stages investigated in this study.

Effects of resting heart rate variability on performance in the P300 brain-computer interface

OBJECTIVE Brain computer interfaces (BCI) can serve as a communication system for people with severe impairment in speech and motor function due to neurodegenerative disease or injury. Reasons for inter-individual differences in capability of BCI usage are not yet fully understood. Paradigms making use of the P300 event-related potential are widely used. Success in a P300 based BCI requires the capability to focus attention and inhibit interference by distracting irrelevant stimuli. Such inhibitory control has been closely linked to peripheral physiological parameters, such as heart rate variability (HRV). The present study investigated the association between resting HRV and performance in the P300-BCI. METHODS Heart rate was recorded from 34 healthy participants under resting conditions, and subsequently a P300-BCI task was performed. RESULTS Frequency domain measures of HRV were significantly associated with BCI-performance, in that higher vagal activation was related to better BCI-performance. CONCLUSIONS Resting HRV accounted for almost 26% of the variance of BCI performance and may, therefore, serve as a predictor for the capacity to control a P300 oddball based BCI. SIGNIFICANCE This is the first study to demonstrate resting vagal-cardiac activation to predict capability of P300-BCI usage.

Prepubertal gonadotropin-releasing hormone analog leads to exaggerated behavioral and emotional sex differences in sheep.

In mammals, sex specialization is reflected by differences in brain anatomy and function. Measurable differences are documented in reproductive behavior, cognition, and emotion. We hypothesized that gonadotropin-releasing hormone (GnRH) plays a crucial role in controlling the extent of the brains sex specificity and that changes in GnRH action during critical periods of brain development, such as puberty, will result in altered sex-specific behavioral and physiological patterns. We blocked puberty in half of the 48 same-sex Scottish mule Texel cross sheep twins with GnRH analog (GnRHa) goserelin acetate every 3 weeks, beginning just before puberty. To determine the effects of GnRHa treatment on sex-specific behavior and emotion regulation in different social contexts, we employed the food acquisition task (FAT) and measurement of heart rate variability (HRV). ANOVA revealed significant sex and sex×treatment interaction effects, suggesting that treated males were more likely to leave their companions to acquire food than untreated, while the opposite effect was observed in females. Concordant results were seen in HRV; treated males displayed higher HRV than untreated, while the reverse pattern was found in females, as shown by significant sex and sex×treatment interaction effects. We conclude that long-term prepubertal GnRHa treatment significantly affected sex-specific brain development, which impacted emotion and behavior regulation in sheep. These results suggest that GnRH is a modulator of cognitive function in the developing brain and that the sexes are differentially affected by GnRH modulation.

Frames, decisions, and cardiac-autonomic control

The “framing effect” (FE) describes the phenomenon whereby human choices are susceptible to the way they are presented rather than objective information. The present study extends common decision-making paradigms with frame variation by including inhibitory control, operationalized as vagally mediated heart rate variability (HRV) at rest and motor response inhibition during a stop-signal task (SST). We hypothesized that inhibitory control is inversely associated with susceptibility to framing effects. Forty adult volunteers performed a risky-choice framing task in which identical information about wins and losses was presented using loss or gain frames. As predicted, there was an inverse association between HRV and framing effects, accounting for 23% of the variance in framing effects. Inhibitory control as indexed by performance in the SST was not associated with framing effects. These results are discussed in terms of the role of inhibitory processes (as indicated by vagal activity) for decision-making processes.

Enhanced cardiac perception predicts impaired performance in the Iowa Gambling Task in patients with panic disorder

Somatic marker theory predicts that somatic cues serve intuitive decision making; however, cardiovascular symptoms are threat cues for patients with panic disorder (PD). Therefore, enhanced cardiac perception may aid intuitive decision making only in healthy individuals, but impair intuitive decision making in PD patients.

Overcoming Selfishness: Reciprocity, Inhibition, and Cardiac-Autonomic Control in the Ultimatum Game

The processes underlying decision-making in response to unfair offers in the ultimatum game (UG) have recently been discussed in light of models of reciprocity and fairness-related behavior. It has been suggested that behavior following norm-oriented, internalized expectations of reciprocity requires overcoming economic self-interest. In this study we investigated both, behavioral and peripheral-physiological indicators of inhibitory capacity related to neuronal networks that are likely to be involved in the behavioral response to unfair offers. Both heart-rate variability as an index of inhibitory capacity, and performance in a motor response inhibition task predicted rejection of unfair offers in an UG, suggesting an important role of inhibitory processes in overcoming economic temptations and regulating behavior conforming to social norms of reciprocity and fairness. The role of parasympathetic activity as a physiological trait-marker predicting inter-individual differences in the rejection of unfair offers is discussed.

Cognitive, emotional and psychosocial functioning of girls treated with pharmacological puberty blockage for idiopathic central precocious puberty

Central precocious puberty (CPP) develops due to premature activation of the hypothalamic-pituitary-gonadal (HPG) axis, resulting in early pubertal changes and rapid bone maturation. CPP is associated with lower adult height and increased risk for development of psychological problems. Standard treatment of CPP is based on postponement of pubertal development by blockade of the HPG axis with gonadotropin releasing hormone analogs (GnRHa) leading to abolition of gonadal sex hormones synthesis. Whereas the hormonal and auxological effects of GnRHa are well-researched, there is a lack of knowledge whether GnRHa treatment influences psychological functioning of treated children, despite the fact that prevention of psychological problems is used as one of the main reasons for treatment initiation. In the present study we seek to address this issue by exploring differences in cognitive function, behavior, emotional reactivity, and psychosocial problems between GnRHa treated CPP girls and age-matched controls. Fifteen girls with idiopathic CPP; median age 10.4 years, treated with slow-release GnRHa (triptorelin acetate—Decapeptyl SR® 11.25) and 15 age-matched controls, were assessed with a comprehensive test battery consisting of paper and pencil tests, computerized tasks, behavioral paradigms, heart rate variability, and questionnaires filled in by the childrens parents. Both groups showed very similar scores with regard to cognitive performance, behavioral and psychosocial problems. Compared to controls, treated girls displayed significantly higher emotional reactivity (p = 0.016; Cohens d = 1.04) on one of the two emotional reactivity task conditions. Unexpectedly, the CPP group showed significantly lower resting heart rates than the controls (p = 0.004; Cohens d = 1.03); lower heart rate was associated with longer treatment duration (r = −0.582, p = 0.037). The results suggest that GnRHa treated CPP girls do not differ in their cognitive or psychosocial functioning from age matched controls. However, they might process emotional stimuli differently. The unexpected finding of lower heart rate that was associated with longer duration of the treatment should be further explored by methods appropriate for assessment of cardiac health.