Effect of practice on the voluntary control of a learned breathing pattern

Monitoring Breathing Muscle Performance During Singing Noninvasively Using Mechanomyography and Electromyography

OBJECTIVES

The aim of this study was to investigate the performance of mechanomyography (MMG) and electromyography (EMG) in monitoring the sternocleidomastoid (SCM) as accessory respiratory muscles when breathing during singing.

METHODS

MMG and EMG were used to record the activity of the SCM in 32 untrained singers reciting a monotonous text and a standard folk song. Their voices were recorded and their pitch, or fundamental frequency (FF), and intensity were derived using Praat software. Instants of inhale and exhales were identified during singing from their voice recordings and the corresponding SCM MMG and EMG activities were analysed.

RESULTS

The SCM MMG, and EMG signals during breathing while singing were significantly different than breathing at rest (p < 0.001). On the other hand, MMG was relatively better correlated to voice intensity in both reading and singing than EMG. EMG was better, but not significantly, correlated with FF in both reading and singing as compared to MMG.

CONCLUSIONS

This study established MMG and EMG as the quantitative measurement tool to monitor breathing activities during singing. This is useful for applications related to singing therapy performance measure including potentially pathologically effected population. While the MMG and EMG could not distinguish FF and intensity significantly, it is useful to serve as a proxy of inhalation and exhalation levels throughout a particular singing session. Further studies are required to determine its efficacy in a therapeutic setting.

Training of paced breathing at 0.1 Hz improves CO2 homeostasis and relaxation during a paced breathing task

Volitional control of breathing often leads to excessive ventilation (hyperventilation) among untrained individuals, which disrupts CO2 homeostasis and may elicit a set of undesirable symptoms. The present study investigated whether seven days of training without any anti-hyperventilation instructions improves CO2 homeostasis during paced breathing at a frequency of 0.1 Hz (6 breaths/minute). Furthermore, the present study investigated the effects of training on breathing-related changes in affective state to examine the hypothesis that training improves the influence of slow paced breathing on affect. A total of 16 participants performed ten minutes of paced breathing every day for seven days. Partial pressure of end-tidal CO2 (PetCO2), symptoms of hyperventilation, affective state (before and after breathing), and pleasantness of the task were measured on the first, fourth, and seventh days of training. Results showed that the drop in PetCO2 significantly decreased with training and none of the participants experienced a drop in PetCO2 below 30 mmHg by day seven of training (except one participant who already had PetCO2 below 30 mmHg during baseline), in comparison to 37.5% of participants on the first day. Paced breathing produced hyperventilation symptoms of mild intensity which did not decrease with training. This suggests that some participants still experienced a drop of PetCO2 that was deep enough to produce noticeable symptoms. Affective state was shifted towards calmness and relaxation during the second and third laboratory measurements, but not during the first measurement. Additionally, the breathing task was perceived as more pleasant during subsequent laboratory measurements. The obtained results showed that training paced breathing at 0.1 Hz led to decrease in hyperventilation. Furthermore, the present study suggests that training paced breathing is necessary to make the task more pleasant and relaxing.

Management of dyspnea guidelines for practice for adults with chronic obstructive pulmonary disease

Dyspnea is an important symptom to address in occupational therapy since it significantly contributes to decreased functional status and health-related quality of life in adults with chronic obstructive pulmonary disease (COPD). This article presents the Management of Dyspnea Guidelines for Practice. The guidelines direct the clinician to help adult patients with COPD overcome the disabling effects of dyspnea by helping patients to master combining controlled breathing with activity exertion and by desensitizing them to dyspnea. An example of an occupational therapy treatment program based on the practice guidelines is described. A case study example is also provided to illustrate how the guidelines can be applied to occupational therapy practice.

The conditioning of dyspneic suffocation fear. Effects of carbon dioxide concentration on behavioral freezing and analgesia

Previous studies in our laboratory have shown that a single exposure to 100% carbon dioxide (CO2) can serve as an effective unconditioned stimulus (US) in a Pavlovian aversive-context conditioning paradigm in rats. Although the US exposure parameters employed in the initial studies were sufficient for producing a context-specific enhancement of behavioral freezing and analgesia, it had yet to be determined whether variations of these CO2 conditioning procedures would produce other conditioning effects. Thus, the purpose of the following experiment was to investigate the intensity of the US on the conditioned response (CR). The findings confirm that variations in CO2 concentrations produce changes in the CR that are consistent with principles of Pavlovian conditioning. The findings lend additional support to the tenability of a dyspneic suffocation fear theory of panic disorder, a theory that postulates that at least one type of panic attack could be a consequence of Pavlovian conditioning.

Learning in respiratory control

In this article, it is argued that learning participates to fulfill the metabolic requirements by adapting respiratory control to changing internal and external states. Recent classical-conditioning experiments in newborn mice or adult rats show the close link between conditioned respiratory and arousal responses. The conditioned fear model may be a suitable and largely unexplored model of emotionally induced hyperventilation. The parabrachial nucleus and periacqueducal grey may play a pivotal role in the ventilatory component of conditioned fear. The sensitivity of breathing to conditioning in newborn and adult animals suggests that learning processes may shape breathing pattern throughout life.

The modification of breathing behavior. Pavlovian and operant control in emotion and cognition

The purpose of this article is to bring attention to breathing as a behavior that can be modified by means of Pavlovian and operant principles of control. With this aim in mind, this paper (a) reviews a selection of early and recent conditioning studies (Pavlovian and operant paradigms) in respiratory psychophysiology, (b) discusses the bidirectional relationship between breathing and emotion/cognition, and (c) discusses theoretical and applied implications that point to new directions for research in the laboratory and clinic. Emphasis is placed on dyspnea/suffocation fear and the acquisition of anticipatory dyspnea/suffocation fear in panic, anxiety, and stress disorders and their concomitant cognitive deficits. Discussions throughout the article focus on research relevant to theory and application, especially applications in programs of remedial breathing (breathing retraining) designed for the treatment of psychophysiological disorders (e.g., panic, anxiety, and stress) and the accompanying cognitive deficits that result from cerebral hypoxia induced by conditioned hyperventilation.

Effects of voluntary changes in breathing frequency on respiratory comfort

Previous experiments on voluntary breathing have suggested that spontaneous breathing is partly determined by the minimization of respiratory sensations. However, during instructed breathing, respiratory sensations may be confounded with difficulty in achieving the prescribed pattern. In the present experiment, we tested the hypothesis that the subjective assessment of respiratory comfort and the difficulty in following breathing instructions are closely related. A total of 15 subjects adjusted breathing frequency to prescribed values ranging from 40 to 250% of individual spontaneous levels. Then, they scored the difficulty of this task and the discomfort associated with the target frequency. Difficulty scores sharply increased above 100% (spontaneous level) and discomfort scores displayed a similar shape. A significant positive correlation between discomfort and difficulty was found, thus suggesting a possible influence of the difficulty to follow ventilatory instructions on respiratory sensation scores.

The effects of breathing pattern training on ventilatory function in patients with COPD

The purpose of this study was to assess the effects of a particular breathing pattern training (BPT) on forced expiratory volume during the first second (FEV1) and forced vital capacity (FVC) in patients with chronic obstructive pulmonary disease (COPD). The subjects adjusted each breath to a target breath displayed on a video screen, by using visual feedback. This target was chosen in an individual sample recorded at rest. We used a randomized, controlled group design. Twenty patients with stable COPD, FEV1 less than 1.5 liters, undergoing a traditional rehabilitation program were randomly assigned to the BPT group or to the control group. Each BPT subject underwent 30-35 training sessions spread out over four weeks, in addition to the traditional program. FEV1 and FVC were performed before and after this program. ANOVAs showed that FEV1 and FVC significantly improved in BPT subjects, with a mean percent increase of 22% and 19%, respectively. Corresponding changes in controls were not significant. This study showed short-term increases in FEV1 and FVC in COPD patients practicing BPT in addition to respiratory rehabilitation, in comparison with controls. Further studies should incorporate outcome data to clarify the mechanisms and the duration of this effect.

Relation between Reaction Time and the Phase of Spontaneous and Controlled Breathing Patterns

In this study simple reaction time (simple RT) to a visual stimulus of a single subject was measured during spontaneous and controlled breathing, in which the duration of expiration was prolonged (Asian technique). The phases of breathing were classified as the pause between expiration and inspiration, the inspiration phase, the transition from inspiration to expiration, and the expiration phase. Analysis of data from about 6000 trials indicated that RT to the stimulus was shortest during the transition from inspiration to expiration in controlled breathing.

Effects of abdominal and thoracic breathing upon multiple-site electromyography and peripheral skin temperature

Peripheral finger temperature, frontalis and upper trapezius EMG, and self-report of arousal were assessed for four subjects during abdominal and thoracic breathing in a single-subject reversal design. Two subjects displayed significant differences between abdominal and thoracic breathing conditions; one for frontalis EMG, trapezius EMG, and self-report of arousal and one for trapezius EMG. Two subjects showed no significant effects. All subjects reached performance criteria during training sessions. Abdominal breathing performance during reversals was 100% and 92% of sampled breath cycles for the two subjects who showed significant change, and 65% and 42% for the two subjects who showed none. Methodological issues for measurement of breathing patterns and peripheral skin temperature are discussed.

Regulation of mental states and biofeedback techniques: effects on breathing pattern

The purpose of the present study was to examine whether breathing pattern may be used as a reliable index for the effectiveness of techniques applied for the regulation of mental states. Heart rate (HR), breathing pattern, galvanic skin response (GSR), and electromyogram (EMG) of the frontalis muscle were measured in 39 male and female subjects aged 18-25 years during 10-minute treatment with relaxation technique (autogenic training and/or music) followed by 10 minutes of imagery training. In the first 7 sessions biofeedback (BFB) was not included, while during the last 6 sessions BFB was introduced and utilized by the subjects. Relaxation (music or autogenic training) led to a decrease in breathing frequency, attributed to lengthening of expiration time, as well as reduced HR, GSR, and frontalis EMG response. In most instances imagery training was related to an increase in these indices. Specifically, significant tachypnea was observed during imagery of sprint running. In most cases BFB substantially augmented the physiological responses. In conclusion, our data suggest that, compared with HR, GSR, and EMG responses, the breathing pattern is at least as sensitive to the mental techniques employed, and may be useful as a psychophysiological index for diagnosis and testing, especially in sport practice.

Ventilatory conditioning by self-stimulation in rats: a pilot study

This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but after prolonged conditioning, the brain stimulation was associated with quiet wakefulness. Although the general procedure appears to be well-suited to the experimental study of voluntary breathing, some possible improvements are suggested for further, more extensive investigations.

Performance and learning during voluntary control of breath patterns

Fourteen subjects learned to adjust their breath pattern to two target breaths displayed on a video screen, by using visual feedback, during two sessions 24 h apart. These two targets were respectively the smallest and the largest breaths of a ten-breath sample previously recorded from each subject's resting spontaneous breathing. Performances were significantly better for the large than for the small target breath. This cannot be directly inferred from current knowledge related to the control of movement time and amplitude, but rather it may be inferred from the periodic character of breathing, to the higher mental load during the small breath task, or to the presumably different frequencies of target breaths in the whole span of spontaneous breathing. In the second session, performance on the two targets levelled out as a result of learning.

The effect of voluntary breathing on reaction time

The effect of voluntary changes in inspiratory duration on reaction time was studied in 17 normal subjects. All received a visual feedback on inspiratory duration and successively adjusted this variable to two target values which were respectively higher and slightly lower than resting level. The order of the two tasks was counterbalanced across subjects. Reaction times to auditory stimuli were measured during a key-pressing task immediately after voluntary breathing. Voluntary control of inspiration induced concomitant changes in breathing period and minute ventilation. Per cent changes in these breathing variables and in reaction times under the two conditions were analysed. Correlations were significant for period not for minute ventilation. This effect was probably due to neuromuscular rather than humoral factors.