| 1. |
- Raizen, David M., et al.
(författare)
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Beyond the symptom : the biology of fatigue
- 2023
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Ingår i: Sleep. - : Oxford University Press. - 0161-8105 .- 1550-9109. ; 46:9
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Tidskriftsartikel (refereegranskat)abstract
- A workshop titled “Beyond the Symptom: The Biology of Fatigue” was held virtually September 27–28, 2021. It was jointly organized by the Sleep Research Society and the Neurobiology of Fatigue Working Group of the NIH Blueprint Neuroscience Research Program. For access to the presentations and video recordings, see: https://neuroscienceblueprint.nih.gov/about/event/beyond-symptom-biology-fatigue.The goals of this workshop were to bring together clinicians and scientists who use a variety of research approaches to understand fatigue in multiple conditions and to identify key gaps in our understanding of the biology of fatigue. This workshop summary distills key issues discussed in this workshop and provides a list of promising directions for future research on this topic. We do not attempt to provide a comprehensive review of the state of our understanding of fatigue, nor to provide a comprehensive reprise of the many excellent presentations. Rather, our goal is to highlight key advances and to focus on questions and future approaches to answering them.
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| 2. |
- Koenig, Julian, et al.
(författare)
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Cortical thickness and resting-state cardiac function across the lifespan : A cross-sectional pooled mega-analysis
- 2021
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Ingår i: Psychophysiology. - : Wiley. - 0048-5772 .- 1469-8986 .- 1540-5958. ; 58:7
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12–87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS—or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
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| 3. |
- Critchley, Hugo D, et al.
(författare)
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Neural systems supporting interoceptive awareness.
- 2004
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Ingår i: Nat Neurosci. - : Springer Science and Business Media LLC. - 1097-6256 .- 1546-1726. ; 7:2, s. 189-95
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Tidskriftsartikel (refereegranskat)abstract
- Influential theories of human emotion argue that subjective feeling states involve representation of bodily responses elicited by emotional events. Within this framework, individual differences in intensity of emotional experience reflect variation in sensitivity to internal bodily responses. We measured regional brain activity by functional magnetic resonance imaging (fMRI) during an interoceptive task wherein subjects judged the timing of their own heartbeats. We observed enhanced activity in insula, somatomotor and cingulate cortices. In right anterior insular/opercular cortex, neural activity predicted subjects' accuracy in the heartbeat detection task. Furthermore, local gray matter volume in the same region correlated with both interoceptive accuracy and subjective ratings of visceral awareness. Indices of negative emotional experience correlated with interoceptive accuracy across subjects. These findings indicate that right anterior insula supports a representation of visceral responses accessible to awareness, providing a substrate for subjective feeling states.
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| 4. |
- Gray, Marcus A, et al.
(författare)
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Following one's heart: cardiac rhythms gate central initiation of sympathetic reflexes.
- 2009
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 29:6, s. 1817-25
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Tidskriftsartikel (refereegranskat)abstract
- Central nervous processing of environmental stimuli requires integration of sensory information with ongoing autonomic control of cardiovascular function. Rhythmic feedback of cardiac and baroreceptor activity contributes dynamically to homeostatic autonomic control. We examined how the processing of brief somatosensory stimuli is altered across the cardiac cycle to evoke differential changes in bodily state. Using functional magnetic resonance imaging of brain and noninvasive beat-to-beat cardiovascular monitoring, we show that stimuli presented before and during early cardiac systole elicited differential changes in neural activity within amygdala, anterior insula and pons, and engendered different effects on blood pressure. Stimulation delivered during early systole inhibited blood pressure increases. Individual differences in heart rate variability predicted magnitude of differential cardiac timing responses within periaqueductal gray, amygdala and insula. Our findings highlight integration of somatosensory and phasic baroreceptor information at cortical, limbic and brainstem levels, with relevance to mechanisms underlying pain control, hypertension and anxiety.
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| 5. |
- Gray, Marcus A, et al.
(författare)
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Modulation of emotional appraisal by false physiological feedback during fMRI.
- 2007
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Ingår i: PLoS ONE. - 1932-6203. ; 2:6, s. e546-
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Tidskriftsartikel (refereegranskat)abstract
- James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories ofemotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions.Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover,anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiologicalarousal. However, the neural underpinnings of these phenomena previously have not been examined. Methodology/Principal Findings. We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and secondorderlevels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of trueand false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faceswas enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behaviouralinteraction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anteriorinsula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change inperceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLDactivity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at botha group and an individual level. Conclusions/Significance. Our findings identify the neural substrates supportingbehavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states,including the importance of the right anterior insula in guiding second-order ‘‘cognitive’’ representations of bodily arousalstate.
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