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False alarms for all participants during the recognition memory task. There was a significant interaction of condition and valence. Osc+ participants had a higher rate of false alarm for neutral and positive images than negative images, while Osc− participants showed no differences in false alarm rate for neutral, positive, or negative images
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Previous research suggests that implicit automatic emotion regulation relies on the medial prefrontal cortex (mPFC). However, most of the human studies supporting this hypothesis have been correlational in nature. In the current study, we examine how changes in mPFC-left amygdala functional connectivity relate to emotional memory biases. In a rando...
Citations
... The Osc+ intervention also increased functional connectivity between the left amygdala and mPFC and within canonical emotion-related brain networks, whereas the Osc-condition did not affect these functional connectivity measures 12 . Emotional memory was more positively biased in the Osc+ than Osc-condition, an effect mediated by change in left amygdala-mPFC functional connectivity 9 . Furthermore, the two interventions affected structural volume in opposing directions in the left orbitofrontal cortex 15 , the region in which we previously had found individual differences in structure to be associated with resting vagal HRV 16,17 . ...
... At the Week-4 visit, the encoding and immediate free recall task were administered and at the Week-5 visit, participants completed the same free recall task followed by a recognition task. For more detail, see Cho et al. 9 . ...
We present data from the Heart Rate Variability and Emotion Regulation (HRV-ER) randomized clinical trial testing effects of HRV biofeedback. Younger (N = 121) and older (N = 72) participants completed baseline magnetic resonance imaging (MRI) including T1-weighted, resting and emotion regulation task functional MRI (fMRI), pulsed continuous arterial spin labeling (PCASL), and proton magnetic resonance spectroscopy (¹H MRS). During fMRI scans, physiological measures (blood pressure, pulse, respiration, and end-tidal CO2) were continuously acquired. Participants were randomized to either increase heart rate oscillations or decrease heart rate oscillations during daily sessions. After 5 weeks of HRV biofeedback, they repeated the baseline measurements in addition to new measures (ultimatum game fMRI, training mimicking during blood oxygen level dependent (BOLD) and PCASL fMRI). Participants also wore a wristband sensor to estimate sleep time. Psychological assessment comprised three cognitive tests and ten questionnaires related to emotional well-being. A subset (N = 104) provided plasma samples pre- and post-intervention that were assayed for amyloid and tau. Data is publicly available via the OpenNeuro data sharing platform.
With age, parasympathetic activity decreases, while sympathetic activity increases. Thus, the typical older adult has low heart rate variability (HRV) and high noradrenaline levels. Younger adults with this physiological profile tend to be unhappy and stressed. Yet, with age, emotional experience tends to improve. Why does older adults’ emotional well‐being not suffer as their HRV decreases? To address this apparent paradox, I present the autonomic compensation model. In this model, failing organs, the initial phases of Alzheimer's pathology, and other age‐related diseases trigger noradrenergic hyperactivity. To compensate, older brains increase autonomic regulatory activity in the pregenual prefrontal cortex (PFC). Age‐related declines in nerve conduction reduce the ability of the pregenual PFC to reduce hyperactive noradrenergic activity and increase peripheral HRV. But these pregenual PFC autonomic compensation efforts have a significant impact in the brain, where they bias processing in favor of stimuli that tend to increase parasympathetic activity (e.g., stimuli that increase feelings of safety) and against stimuli that tend to increase sympathetic activity (e.g., threatening stimuli). In summary, the autonomic compensation model posits that age‐related chronic sympathetic/noradrenergic hyperactivity stimulates regulatory attempts that have the side effect of enhancing emotional well‐being.
Many studies have examined the effects of meditation practice focused on the normal breath on vagal tone with mixed results. Heart Rhythm Meditation (HRM) is a unique meditation form that engages in the deep slow full breath, and puts the focus of attention on the heart. This form of breathing likely stimulates the vagus nerve with greater intensity. The purpose of this study was (a) to examine how the practice of HRM affects vagal activity as measured by heart rate variability (HRV); and (b) to examine how it affects participants’ well-being. 74 participants signed consent agreeing to: (a) take a six-week course to learn the practice of HRM; (b) engage in a daily practice for 10 weeks; (c) have their heart rate variability read through ECG technology and to take two validated well-being instruments at the beginning and end of the 10 weeks; and (d) participate in a focus group interview examining their perceptions of how the practice affected their well-being. 48 participants completed the study. Quantitative findings show the effect of the practice of HRM approached significance for multiple measures of HRV and vagal tone. An increase in well-being scores for those who did the meditation more than 10-minutes per day did meet statistical significance. Qualitative data indicate: (a) the positive effects of HRM on stress and well-being; (b) the development of a more expanded sense of self; and (c) an increased awareness of the interconnection of the body-heart-emotions and HRM’s role in emotion regulation.
Background
In healthy people, the “fight-or-flight” sympathetic system is counterbalanced by the “rest-and-digest” parasympathetic system. As we grow older, the parasympathetic system declines as the sympathetic system becomes hyperactive. In our prior heart rate variability biofeedback and emotion regulation (HRV-ER) clinical trial, we found that increasing parasympathetic activity through daily practice of slow-paced breathing significantly decreased plasma amyloid-β (Aβ) in healthy younger and older adults. In healthy adults, higher plasma Aβ is associated with greater risk of Alzheimer’s disease (AD). Our primary goal of this trial is to reproduce and extend our initial findings regarding effects of slow-paced breathing on Aβ. Our secondary objectives are to examine the effects of daily slow-paced breathing on brain structure and the rate of learning.
Methods
Adults aged 50–70 have been randomized to practice one of two breathing protocols twice daily for 9 weeks: (1) “slow-paced breathing condition” involving daily cognitive training followed by slow-paced breathing designed to maximize heart rate oscillations or (2) “random-paced breathing condition” involving daily cognitive training followed by random-paced breathing to avoid increasing heart rate oscillations. The primary outcomes are plasma Aβ40 and Aβ42 levels and plasma Aβ42/40 ratio. The secondary outcomes are brain perivascular space volume, hippocampal volume, and learning rates measured by cognitive training performance. Other pre-registered outcomes include plasma pTau-181/tTau ratio and urine Aβ42. Recruitment began in January 2023. Interventions are ongoing and will be completed by the end of 2023.
Discussion
Our HRV-ER trial was groundbreaking in demonstrating that a behavioral intervention can reduce plasma Aβ levels relative to a randomized control group. We aim to reproduce these findings while testing effects on brain clearance pathways and cognition.
Trial registration
ClinicalTrials.gov NCT05602220. Registered on January 12, 2023.
Background
Despite accumulation of a substantial body of literature supporting the role of exercise on frontal lobe functioning, relatively less is understood of the interconnectivity of ventromedial prefrontal cortical (vmPFC) regions that underpin cardio-autonomic regulation predict cardiac chronotropic competence (CC) in response to sub-maximal exercise.
Methods
Eligibility of 161 adults (mean age = 48.6, SD = 18.3, 68% female) was based upon completion of resting state brain scan and sub-maximal bike test. Sliding window analysis of the resting state signal was conducted over 45-s windows, with 50% overlap, to assess how changes in photoplethysmography-derived HRV relate to vmPFC functional connectivity with the whole brain. CC was assessed based upon heart rate (HR) changes during submaximal exercise (HR change /HRmax (206–0.88 × age) – HRrest).
Results
During states of elevated HRV the vmPFC showed greater rsFC with an 83-voxel region of the hypothalamus (p < 0.001, uncorrected). Beta estimates of vmPFC connectivity extracted from a 6-mm sphere around this region emerged as the strongest predictor of CC (b = 0.283, p <.001) than age, BMI, and resting HRV F(8,144) = 6.30, p <.001.
Conclusion
Extensive glutamatergic innervation of the hypothalamus by the vmPFC allows for top-down control of the hypothalamus and its various autonomic efferents which facilitate chronotropic response during sub-maximal exercise.
Introduction. In modern conditions humans are exposed to the high level of stress that causes the gain in psychosomatic disorders. The problem of tolerance to increasing stress is becoming more and more urgent. The study of the possibilities of the dorsolateral prefrontal cortex stimulation, which affects the mechanisms of autonomic regulation, is of clinical interest. The aim of the study is to research the mechanisms of the resistance to increasing stress after transcranial magnetic stimulation of the dorsolateral prefrontal cortex of the right hemisphere in young males engaged in mental work. Materials and methods. Thirty four healthy male 20 to 22 years students were observed. Transcranial magnetic stimulation of the dorsolateral prefrontal cortex projection at the F4 point in the electrode system marked “10–20” was carried out with an individually determined stimulus intensity in the amount of 300 stimuli with a frequency of 1 Hz. Autonomic effects were evaluated using spectral analysis of heart rate variability before and after stimulation. Seven-test was used as a stress test. Results. The predominance of oscillations in the low frequency of heart rate variability, indicating sympathetic activation, was determined in the examined young men, engaged in mental labour. After stimulation of the prefrontal cortex, there was an increase in heart rate variability, to a greater extent very low frequency oscillations associated with the central mechanisms of parasympathetic activity. During the stress test, the increase in adaptive capabilities was manifested by a less pronounced decrease in heart rate variability in comparison to the reaction before stimulation. A model of the effect of stimulation of the dorsolateral prefrontal cortex on heart rate variability was proposed. Limitations. The study is limited to the evaluation of spectral parameters of heart rate variability in 34 young healthy students before and after transcranial magnetic stimulation of the dorsolateral prefrontal cortex. Conclusion. Stimulation of the prefrontal cortex increased the adaptive capabilities of the body and can be used to increase stress resistance in people with intellectual work.
