Hypothesis: Pulmonary Afferent Activity Patterns During Slow, Deep Breathing Contribute to the Neural Induction of Physiological Relaxation

AbstractThe stabilizing role of sensory feedback in relation to realistic 3-dimensional movement dynamics remains poorly understood. The objective of this study was to quantify how primary afferent activity contributes to shaping muscle activity patterns during reaching movements. To achieve this objective, we designed a virtual reality task that guided healthy human subjects through a set of planar reaching movements with controlled kinematic and dynamic conditions that minimized inter-subject variability. Next, we integrated human upper-limb models of musculoskeletal dynamics and proprioception to analyze motion and major muscle activation patterns during these tasks. We recorded electromyographic and motion-capture data and used the integrated model to simulate joint kinematics, joint torques due to muscle contractions, muscle length changes, and simulated primary afferent feedback. The parameters of the primary afferent model were altered systematically to evaluate the effect of fusimotor drive. The experimental and simulated data were analyzed with hierarchical clustering. We found that the muscle activity patterns contained flexible task-dependent groups that consisted of co-activating agonistic and antagonistic muscles that changed with the dynamics of the task. The activity of muscles spanning only the shoulder generally grouped into a proximal cluster, while the muscles spanning the wrist grouped into a distal cluster. The bifunctional muscle spanning the shoulder and elbow were flexibly grouped with either proximal or distal cluster based on the dynamical requirements of the task. The composition and activation of these groups reflected the relative contribution of active and passive forces to each motion. In contrast, the simulated primary afferent feedback was most related to joint kinematics rather than dynamics, even though the primary afferent models had nonlinear dynamical components and variable fusimotor drive. Simulated physiological changes to the fusimotor drive were not sufficient to reproduce the dynamical features in muscle activity pattern. Altogether, these results suggest that sensory feedback signals are in a different domain from that of muscle activation signals. This indicates that to solve the neuromechanical problem, the central nervous system controls limb dynamics through task-dependent co-activation of muscles and non-linear modulation of monosynaptic primary afferent feedback.New & NoteworthyHere we answered the fundamental question in sensorimotor transformation of how primary afferent signals can contribute to the compensation for limb dynamics evident in muscle activity. We combined computational and experimental approaches to create a new experimental paradigm that challenges the nervous system with passive limb dynamics that either assists or resists the desired movement. We found that the active dynamical features present in muscle activity are unlikely to arise from direct feedback from primary afferents.

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Effectiveness of Progressive Muscle Relaxation, Deep Breathing, and Guided Imagery in Promoting Psychological and Physiological States of Relaxation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/5924040 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Loren Toussaint ◽

Quang Anh Nguyen ◽

Claire Roettger ◽

Kiara Dixon ◽

Martin Offenbächer ◽

...

Keyword(s):

Stress Relaxation ◽

Relaxation Training ◽

Guided Imagery ◽

Muscle Relaxation ◽

The Body ◽

Progressive Muscle Relaxation ◽

Control Group ◽

Deep Breathing ◽

Physiological Level ◽

Physiological Relaxation

Research suggests that multiple forms of relaxation training (e.g., progressive muscle relaxation, meditation, breathing exercises, visualization, and autogenics) can help individuals reduce stress, enhance relaxation states, and improve overall well-being. We examined three different, commonly used approaches to stress relaxation—progressive muscle relaxation, deep breathing, and guided imagery—and evaluated them in a head-to-head comparison against each other and a control condition. Sixty healthy undergraduate participants were randomized to one of the four conditions and completed 20 minutes of progressive muscle relaxation, deep breathing, or guided imagery training that was delivered by recorded audio instruction. Baseline and follow-up assessment of psychological relaxation states were completed. Physiological relaxation was also assessed continuously using measures of electrodermal activity and heart rate. Results showed that progressive muscle relaxation, deep breathing, and guided imagery all increased the state of relaxation for participants in those groups, compared to participants in the control group. In each case, the increase was statistically significant and although the groups did not differ on relaxation before training, all groups were significantly higher on relaxation after training, as compared to the control group. Progressive muscle relaxation and guided imagery showed an immediate linear trend toward physiological relaxation, compared to the control group, and the deep breathing group showed an immediate increase in physiological arousal followed quickly by a return to initial levels. Our results lend support to the body of research showing that stress relaxation training can be effective in improving relaxation states at both the psychological and physiological level. Future research could examine stress relaxation techniques in a similar manner using designs where multiple techniques can be compared in the same samples.

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Behavior of cutaneous mechanoreceptors recorded in mandibular division of Gasserian ganglion of the rabbit during movements of lower jaw

Journal of Neurophysiology ◽

10.1152/jn.1982.47.2.151 ◽

1982 ◽

Vol 47 (2) ◽

pp. 151-166 ◽

Cited By ~ 29

Author(s):

K. Appenteng ◽

J. P. Lund ◽

J. J. Seguin

Keyword(s):

Hair Follicle ◽

Activity Patterns ◽

Receptive Fields ◽

Firing Frequency ◽

Gasserian Ganglion ◽

Afferent Activity ◽

Cutaneous Mechanoreceptors ◽

Lower Jaw ◽

Movement Parameters ◽

Anterior Posterior

1. The activity of cutaneous mechanoreceptors was recorded extracellularly in the mandibular division of the Gasserian ganglion of hemidecerebrate anesthetized rabbits. Fifty-four hair follicle afferents and 80 skin mechanoreceptor afferents were functionally identified. Their receptive-field characteristics were described and their activity patterns were recorded while the jaw was displaced by hand in the vertical, horizontal, and anterior-posterior directions, and during masticatory movements. 2. All hair follicle afferents were classified as rapidly adapting, whereas skin afferents could be divided into two categories: rapidly adapting and slowly adapting. Rapidly and slowly adapting receptors were found in all regions of the mandibular skin. Only one hair follicle afferent and four skin afferents fired spontaneously with the jaw at rest. 3. Fifty-eight percent (29/50) of the hair follicle afferents were activated by imposed displacement of the jaw and all of these tested also discharged during chewing. They were sensitive to movement in all three axes and their firing frequency was linearly related to the velocity, regardless of direction. 4. Only 10% (8/80) of the skin afferents were activated by imposed displacement of the jaw if their receptive fields were not directly contacted. Firing frequency was not well related to either the amplitude or velocity of movement. During chewing, the discharge frequency was variable but, in general, firing was restricted to the jaw-closing phase. Most skin afferents that were active during jaw movement had receptive fields close to the corner of the mouth. 5. The results are discussed within the context of a possible involvement of cutaneous afferents in kinesthesia and in the control of jaw movements. Hair afferents could make specific contributions to the appreciation of movement because their discharge pattern was clearly related to one of its parameters. The lack of activity of most skin afferents, as well as the absence of a strong correlation between the firing frequency of those that were active and the movement parameters, suggest that they do not make specific contributions to the awareness of movement. 6. Hair and skin afferents may also make different contributions to the control of ongoing movements. It is suggested that skin afferent activity during jaw closure may elicit a reflex reduction in the velocity or duration of this phase. Some evidence from other studies suggests that hair afferent activity may indirectly influence movement via effects on elevator fusimotor neurons.

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Predicting spatial activity patterns in a neural map from a probabilistic atlas of 3-D reconstructed neurons

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140439 ◽

1995 ◽

Vol 53 ◽

pp. 812-813

Author(s):

G. Jacobs ◽

F. Theunissen

Keyword(s):

Activity Patterns ◽

Three Dimensional ◽

Sensory System ◽

Neural System ◽

Probabilistic Atlas ◽

Uniform Sample ◽

Dimensional Reconstruction ◽

The Time Domain ◽

And Function ◽

Visualization Techniques

In order to understand how the algorithms underlying neural computation are implemented within any neural system, it is necessary to understand details of the anatomy, physiology and global organization of the neurons from which the system is constructed. Information is represented in neural systems by patterns of activity that vary in both their spatial extent and in the time domain. One of the great challenges to microscopists is to devise methods for imaging these patterns of activity and to correlate them with the underlying neuroanatomy and physiology. We have addressed this problem by using a combination of three dimensional reconstruction techniques, quantitative analysis and computer visualization techniques to build a probabilistic atlas of a neural map in an insect sensory system. The principal goal of this study was to derive a quantitative representation of the map, based on a uniform sample of afferents that was of sufficient size to allow statistically meaningful analyses of the relationships between structure and function.

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234 Persons with asymptomatic left ventricle dysfunction can not increase heart rate variability during deep breathing

European Journal of Heart Failure Supplements ◽

10.1016/s1567-4215(04)90161-0 ◽

2004 ◽

Vol 3 (1) ◽

pp. 54-55

Author(s):

D TRIFUNOVICZAMAKLAR

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Left Ventricle ◽

Increase Heart Rate ◽

Deep Breathing ◽

Left Ventricle Dysfunction

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Inducing Unconscious Stress

Journal of Psychophysiology ◽

10.1027/0269-8803/a000247 ◽

2020 ◽

Vol 34 (3) ◽

pp. 192-201

Author(s):

Melanie M. van der Ploeg ◽

Jos F. Brosschot ◽

Markus Quirin ◽

Richard D. Lane ◽

Bart Verkuil

Keyword(s):

Repeated Measures ◽

Activity Patterns ◽

Physiological Changes ◽

Implicit Measures ◽

Prime Word ◽

Student Sample ◽

Priming Task ◽

Subject Design ◽

The Relationship ◽

Stress And Health

Abstract. Stress-related stimuli may be presented outside of awareness and may ultimately influence health by causing repetitive increases in physiological parameters, such as blood pressure (BP). In this study, we aimed to corroborate previous studies that demonstrated BP effects of subliminally presented stress-related stimuli. This would add evidence to the hypothesis that unconscious manifestations of stress can affect somatic health. Additionally, we suggest that these findings may be extended by measuring affective changes relating to these physiological changes, using measures for self-reported and implicit positive and negative affectivity. Using a repeated measures between-subject design, we presented either the prime word “angry” ( n = 26) or “relax” ( n = 28) subliminally (17 ms) for 100 trials to a student sample and measured systolic and diastolic BP, heart rate (HR), and affect. The “angry” prime, compared to the “relax” prime, did not affect any of the outcome variables. During the priming task, a higher level of implicit negative affect (INA) was associated with a lower systolic BP and diastolic BP. No association was found with HR. Self-reported affect and implicit positive affect were not related to the cardiovascular (CV) activity. In sum, anger and relax primes elicited similar CV activity patterns, but implicit measures of affect may provide a new method to examine the relationship between (unconscious) stress and health.

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