Anita L. Hansen

Heart rate variability, prefrontal neural function, and cognitive performance: the neurovisceral integration perspective on self-regulation, adaptation, and health.

BackgroundIn the present paper, we describe a model of neurovisceral integration in which a set of neural structures involved in cognitive, affective, and autonomic regulation are related to heart rate variability (HRV) and cognitive performance.MethodsWe detail the pathways involved in the neural regulation of the cardiovascular system and provide pharmacological and neuroimaging data in support of the neural structures linking the central nervous system to HRV in humans. We review a number of studies from our group showing that individual differences in HRV are related to performance on tasks associated with executive function and prefrontal cortical activity. These studies include comparisons of executive- and nonexecutive-function tasks in healthy participants, in both threatening and nonthreatening conditions. In addition, we show that manipulating resting HRV levels is associated with changes in performance on executive-function tasks. We also examine the relationship between HRV and cognitive performance in ecologically valid situations using a police shooting simulation and a naval navigation simulation. Finally, we review our studies in anxiety patients, as well as studies examining psychopathy.ConclusionThese findings in total suggest an important relationship among cognitive performance, HRV, and prefrontal neural function that has important implications for both physical and mental health. Future studies are needed to determine exactly which executive functions are associated with individual differences in HRV in a wider range of situations and populations.

Vagal influence on working memory and attention

The aim of the present study was to investigate the effect of vagal tone on performance during executive and non-executive tasks, using a working memory and a sustained attention test. Reactivity to cognitive tasks was also investigated using heart rate (HR) and heart rate variability (HRV). Fifty-three male sailors from the Royal Norwegian Navy participated in this study. Inter-beat-intervals were recorded continuously for 5 min of baseline, followed by randomized presentation of a working memory test (WMT) based on Baddeley and Hitchs research (1974) and a continuous performance test (CPT). The session ended with a 5-min recovery period. High HRV and low HRV groups were formed based on a median split of the root mean squared successive differences during baseline. The results showed that the high HRV group showed more correct responses than the low HRV group on the WMT. Furthermore, the high HRV group showed faster mean reaction time (mRT), more correct responses and less error, than the low HRV group on the CPT. Follow-up analysis revealed that this was evident only for components of the CPT where executive functions were involved. The analyses of reactivity showed a suppression of HRV and an increase in HR during presentation of cognitive tasks compared to recovery. This was evident for both groups. The present results indicated that high HRV was associated with better performance on tasks involving executive function.

Heart rate variability and its relation to prefrontal cognitive function: the effects of training and detraining

The aim of the present study was to investigate the relationship between physical fitness, heart rate variability (HRV) and cognitive function in 37 male sailors from the Royal Norwegian Navy. All subjects participated in an 8-week training program, after which the subjects completed the initial cognitive testing (pre-test). The subjects were assigned into a detrained group (DG) and a trained group (TG) based on their application for further duty. The DG withdrew from the training program for 4 weeks after which all subjects then completed the cognitive testing again (post-test). Physical fitness, measured as maximum oxygen consumption (V̇O2max), resting HRV, and cognitive function, measured using a continuous performance task (CPT) and a working memory test (WMT), were recorded during the pre-test and the post-test, and the data presented as the means and standard deviations. The results showed no between-group differences in V̇O2max or HRV at the pre-test. The DG showed a significant decrease in V̇O2max from the pre- to the post-test and a lower resting HRV than the TG on the post-test. Whereas there were no between-group differences on the CPT or WMT at the pre-test, the TG had faster reaction times and more true positive responses on tests of executive function at the post-test compared to the pre-test. The DG showed faster reaction times on non-executive tasks at the post-test compared to the pre-test. The results are discussed within a neurovisceral integration framework linking parasympathetic outflow to the heart to prefrontal neural functions.

Relationship between heart rate variability and cognitive function during threat of shock

Abstract The aim of the present study was to investigate the relationship between resting heart rate variability (HRV) and cognitive functions during threat of shock. A Continuous Performance Task and a Working Memory Task were used to measure cognitive functions. Sixty-five male participants from the Royal Norwegian Navy participated. HRV was measured during baseline, test conditions and recovery. Participants were randomly assigned into non-threat and threat groups. Based on the median split of the high frequency (HF) spectral power, groups were divided into two additional groups. Overall, the high HRV participants showed superior performance on cognitive tasks independent of non-threat or threat conditions. During threat condition the low HRV group showed improved performance. Thus, individuals with high HRV were more stress tolerant and resilient in the face of environmental changes. The results from the study might have implications with regard to performance in operational settings, but also for other fields of psychological research such as individual differences, anxiety and coping.

The relationships among heart rate variability, executive functions, and clinical variables in patients with panic disorder.

Heart rate variability (HRV) is reduced in patients who suffer from panic disorder (PD). Reduced HRV is related to hypoactivity in the prefrontal cortex (PFC), which negatively affects executive functioning. The present study assessed the relationships between vagally mediated HRV at baseline and measures of executive functioning in 36 patients with PD. Associations between these physiological and cognitive measures and panic-related variables were also investigated. HRV was measured using HF-power (ms(2)), and executive functions were assessed with the Wisconsin Card Sorting Test (WCST) and the Color-Word Interference Test (CWIT) from the Delis-Kaplan Executive Function System (D-KEFS). Panic-related variables comprised panic frequency, panic-related distress, and duration of PD. Performance on the neuropsychological measures correlated significantly with HRV. Both panic-related distress and duration of PD were inversely related with measures of HRV and cognitive inhibition. The current findings support the purported relationship between HRV and executive functions involving the PFC.

The Non-invasive Assessment of Autonomic Influences on the Heart Using Impedance Cardiography and Heart Rate Variability

A major goal of the present chapter is to try to provide a comprehensive framework that researchers can use to generate testable hypotheses about the autonomic influences on the heart. This will include a brief discussion of the differential autonomic influences on different cardiac effector tissues including sympathetic–parasympathetic interactions as well as the discussion of cardiovascular activation components and the baroreflex. In addition, we will briefly overview the genetics as well as the neural concomitants of impedance derived indices and heart rate variability (HRV). Another goal will be to expose researchers to the range of phenomena that might be related to measures of impedance cardiography and HRV. These include aspects of physiological regulation, emotional regulation, and cognitive regulation. Finally, we will try to present what we perceive to be some of the future challenges in using these important techniques.

Sleep Deprivation and Hemispheric Asymmetry for Facial Recognition Reaction Time and Accuracy

We investigated the processing of emotional stimuli during a nonsleep-deprived state and following sleep deprivation in 36 right-handed men. Using the visual half-field technique, cartoon line drawings of emotional facial expressions were flashed on a computer screen for 250 msec. The participants were instructed to remember the content of the picture seen and to recognize it among nine alternatives shown immediately after the display of a single picture. Compared to the nondeprived condition, response latencies increased and accuracy decreased in sleep deprivation. Moreover, response latencies indicated that the performance of the right hemisphere deteriorated more following sleep deprivation than did the performance of the left hemisphere. The results also showed that hemispheric preference (for response latencies and response accuracy) tended to favour the left hemisphere when the participants were tested during sleep deprivation.

BRIEF COMMUNICATION: PSYCHOPATHY AND RECOGNITION OF FACIAL EXPRESSIONS OF EMOTION

This study investigated the relationship between symptom clusters of psychopathy, as measured by the Hare Psychopathy Checklist-Revised (PCL-R; Hare 1991), and ability to recognize facial expressions of emotion. Participants were 43 adult male inmates. Facial expressions of emotion were taken from Ekman and Frisen (1976). The present results indicated that there were some significant relationships between facets of psychopathy and processing of disgust facial expressions. The experiment highlighted the importance of studying specific clusters of psychopathic symptoms, as opposed to measures of global symptomatology.

Fish consumption, sleep, daily functioning, and heart rate variability.

STUDY OBJECTIVES This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such as heart rate variability (HRV), vitamin D status (serum 25-hydroxyvitamin D (25OHD), and eicosapentaenoic acid (EPA, 20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3) in red blood cells. Moreover the relationship among sleep, daily functioning, HRV, vitamin D status, and levels of EPA+DHA was investigated. METHODS Ninety-five male forensic patients from a secure forensic inpatient facility in the USA were randomly assigned into a Fish or a Control group. The Fish group received Atlantic salmon three times per week from September to February, and the Control group was provided an alternative meal (e.g., chicken, pork, beef), but with the same nutritional value as their habitual diet, three times per week during the same period. Sleep (sleep latency, sleep efficiency, actual sleep time, and actual wake time), self-perceived sleep quality and daily functioning, as well as vitamin D status, EPA+DHA, and HRV, were assessed pre- and post-intervention period. RESULTS There was a significant increase in sleep latency from pre- to post-test in the Control group. The Fish group reported better daily functioning than the Control group during post-test. Fish consumption throughout the wintertime had also an effect on resting HRV and EPA+DHA, but not on vitamin D status. However, at post-test, the vitamin D status in the Fish group was still closer to the level regarded as optimal compared to the Control group. Vitamin D status correlated negatively with actual wake time and positively with sleep efficiency during pre-test, as well as positively with daily functioning and sleep quality during post-test. Finally, HRV correlated negatively with sleep latency and positively with daily functioning. CONCLUSIONS Fish consumption seemed to have a positive impact on sleep in general and also on daily functioning, which may be related to vitamin D status and HRV.

Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials

BACKGROUND It is well known that fish is the major natural source of vitamin D in the diet; therefore, this meta-analysis investigated the influence of fish consumption in randomized controlled trials (RCTs) on serum 25-hydroxyvitamin D [25(OH)D] concentrations. OBJECTIVE A literature search was carried out in Medline, Embase, Web of Science, and the Cochrane Library (up to February 2014) for RCTs that investigated the effect of fish consumption on 25(OH)D concentrations in comparison to other dietary interventions. RESULTS Seven articles and 2 unpublished study data sets with 640 subjects and 14 study groups met the inclusion criteria and were included in this meta-analysis. Compared with controls, the consumption of fish increased 25(OH)D concentrations, on average, by 4.4 nmol/L (95% CI: 1.7, 7.1 nmol/L; P < 0.0001, I(2) = 25%; 9 studies).The type of the fish also played a key role: the consumption of fatty fish resulted in a mean difference of 6.8 nmol/L (95% CI: 3.7, 9.9 nmol/L; P < 0.0001, I(2) = 0%; 7 study groups), whereas for lean fish the mean difference was 1.9 nmol/L (95% CI: -2.3, 6.0 nmol/L; P < 0.38, I(2) = 37%; 7 study groups). Short-term studies (4-8 wk) showed a mean difference of 3.8 nmol/L (95% CI: 0.6, 6.9 nmol/L; P < 0.02, I(2) = 38%; 10 study groups), whereas in long-term studies (∼6 mo) the mean difference was 8.3 nmol/L (95% CI: 2.1, 14.5 nmol/L; P < 0.009, I(2) = 0%; 4 study groups). CONCLUSION As the major food source of vitamin D, fish consumption increases concentrations of 25(OH)D, although recommended fish intakes cannot optimize vitamin D status.