The impact of dyspnea and threat of dyspnea on error processing

Dyspnea induced by inspiratory loading limits dual-tasking in healthy young adults

OBJECTIVES

Dyspnea is a common and multidimensional experience of healthy adults and those with respiratory disorders. Due to its neural processing, it may limit or interfere with cognition, which may be examined with a dual-task paradigm. The aim of this study was to compare single-task performance of Stroop Colour and Word Test (SCWT) or inspiratory threshold loading (ITL) to their combined dual-task performance. Secondly, whether mood was related to dyspnea or cognitive performance was also evaluated.

MATERIALS & METHODS

A virtual pre-post design examined single (SCWT and ITL) and dual-task (SCWT+ITL) performance. For ITL, a Threshold Trainer™ was used to elicit a "somewhat severe" rating of dyspnea. The SCWT required participants to indicate whether a colour-word was congruent or incongruent with its semantic meaning. The Depression, Anxiety and Stress Scale-21 (DASS-21) was completed to assess mood. Breathing frequency, Borg dyspnea rating, and breathing endurance time were ascertained.

RESULTS

Thirty young healthy adults (15F, 15M; median age = 24, IQR [23-26] years) completed the study. SCWT+ITL had lower SCWT accuracy compared to SCWT alone (98.6%, [97.1-100.0] vs 99.5%, [98.6-100.0]; p = 0.009). Endurance time was not different between ITL and SCWT+ITL (14.5 minutes, [6.9-15.0]) vs 13.7 minutes, [6.1-15.0]; p = 0.59). DASS-21 scores positively correlated with dyspnea scores during ITL (rho = 0.583, p<0.001) and SCWT+ITL (rho = 0.592, p<0.001).

CONCLUSIONS

ITL significantly reduced dual-task performance in healthy young adults. Lower mood was associated with greater perceived dyspnea during single and dual-task ITL. Considering the prevalence of dyspnea in respiratory disorders, the findings of this dual task paradigm warrant further exploration to inform dyspnea management during daily activities.

Error Processing and Pain: A New Perspective

Errors put organisms in danger. Upon error commission, error processing allows for the updating of behavior that proved ineffective in light of the current context and goals, and for the activation of behavioral defensive systems. Pain, on the other hand, signals actual or potential danger to one's physical integrity and, likewise, motivates protective behavior. These parallels suggest the existence of cross-links between pain and error processing but so far their relationship remains elusive. In this review, we tie together findings from the field of pain research with those from electroencephalography studies on error processing [specifically the Error Related Negativity (ERN) and Positivity (Pe)]. More precisely, we discuss three plausible associations: Firstly, pain may enhance error processing as it increases error salience. Secondly, persons fearful of pain may be particularly vigilant towards painful errors and thus show a stronger neural response to them. Thirdly, the ERN as a component of the neural response to error commission is considered an endophenotype of threat sensitivity. As high sensitivity to pain threats is known to incite avoidance behavior, this raises the intriguing possibility that neural signatures of error processing predict pain-related protective behaviors, such as avoidance. We propose an integration of these findings into a common framework to inspire future research. Perspectives Inspired by research in anxiety disorders, we discuss the potential bi-directional relationships between error processing and pain, and identify future directions to examine the neural and psychological processes involved in acute and chronic pain and respective avoidance behavior.

Breathing control, brain, and bodily self-consciousness: Toward immersive digiceuticals to alleviate respiratory suffering

Breathing is peculiar among autonomic functions through several characteristics. It generates a very rich afferent traffic from an array of structures belonging to the respiratory system to various areas of the brain. It is intimately associated with bodily movements. It bears particular relationships with consciousness as its efferent motor control can be automatic or voluntary. In this review within the scope of "respiratory neurophysiology" or "respiratory neuroscience", we describe the physiological organisation of breathing control. We then review findings linking breathing and bodily self-consciousness through respiratory manipulations using virtual reality (VR). After discussing the currently admitted neurophysiological model for dyspnea, as well as a new Bayesian model applied to breathing control, we propose that visuo-respiratory paradigms -as developed in cognitive neuroscience- will foster insights into some of the basic mechanisms of the human respiratory system and will also lead to the development of immersive VR-based digital health tools (i.e. digiceuticals).

Is it a painful error? The effect of unpredictability and intensity of punishment on the error-related negativity, and somatosensory evoked potentials

We examined how predictable and unpredictable punishment intensity contingent on error commission modulated ERN amplitudes. We recorded the ERN in 35 healthy volunteers performing the Eriksen flanker task. Errors were punished with predictable nonpainful, painful or unpredictable electrical stimulation. Furthermore, we investigated trait anxiety. We observed that ERN amplitudes did not differ across conditions, nor were there significant effects of anxiety. In contrast, we found that predictable painful punishments led to smaller Error Positivity (Pe). The effects of predictability and intensity were present in Somatosensory Evoked Potentials elicited by the punishments. N1 amplitudes were increased for painful compared to nonpainful stimulation, and P2/P3 amplitudes for painful compared to nonpainful, and for unpredictable compared to predictable stimulation. We suggest that unpredictability and increased painfulness of punishments enhance the potential motivational significance of the errors, but do not potentiate ERN amplitudes beyond the ones elicited by errors punished with predictable nonpainful stimulation.

Pain by mistake: investigating a link between error-related negativity and pain avoidance behavior

ABSTRACT

Pain can be considered as a signal of "bodily error": Errors put organisms at danger and activate behavioral defensive systems. If the error is of physical nature, pain is the warning signal that motivates protective action such as avoidance behavior to safeguard our body's integrity. Interestingly, an important component of neural error processing, the error-related negativity (ERN), has been found to be related to avoidance in anxiety disorders. The present study is the first to extend these findings to pain and investigate the relationship between ERN and pain-related avoidance behavior. It was hypothesized that individuals with larger ERN amplitudes would show more pain-related avoidance behavior and would be more persistent in their avoidance despite changes in the environment. Fifty-three healthy individuals performed the Eriksen Flanker task during which their brain activity upon correct and erroneous motor responses was recorded by means of high-density electroencephalography. Avoidance behavior was assessed with an arm-reaching task using the HapticMaster robot arm. Results showed that, in contrast to our hypothesis, avoidance was not related to ERN amplitudes. Surprisingly, persons with elevated ERN amplitudes showed low levels of avoidance specifically during early acquisition trials. In contrast to earlier findings in anxiety disorders, individuals with elevated ERN amplitudes did not engage in more pain-related avoidance behavior. In fact, the opposite pattern was found at the start of acquisition: individuals with higher compared to lower ERN amplitudes were slower in learning to avoid pain. Replications and future studies on the relationship between ERN and avoidance behavior are needed.

The impact of unpredictability of dyspnea offset on dyspnea perception, fear, and respiratory neural gating

Dyspnea is a debilitating and threatening symptom in various diseases. Affected patients often report the unpredictability of dyspnea episodes being particularly anxiety-provoking and amplifying the perception of dyspnea. Experimental studies testing dyspnea unpredictability together with related neural processes, physiological fear responses, and dyspnea-related personality traits are sparse. Therefore, we investigated the impact of unpredictability of dyspnea offset on dyspnea perception and fear ratings, respiratory neural gating and physiological fear indices, as well as the influence of interindividual differences in fear of suffocation (FoS). Forty healthy participants underwent a task manipulating the offset predictability of resistive load-induced dyspnea including one unloaded safety condition. Respiratory variables, self-reports of dyspnea intensity, dyspnea unpleasantness, and fear were recorded. Moreover, respiratory neural gating was measured in a paired inspiratory occlusion paradigm using electroencephalography, while electrodermal activity, startle eyeblink, and startle probe N100 were assessed as physiological fear indices. Participants reported higher dyspnea unpleasantness and fear when dyspnea offset was unpredictable compared to being predictable. Individuals with high levels of FoS showed the greatest increase in fear and overall higher levels of fear and physiological arousal across all conditions. Respiratory neural gating, startle eyeblink, and startle probe N100 showed general reductions during dyspnea conditions but no difference between unpredictable and predictable dyspnea conditions. Together, the current results suggest that the unpredictable offset of dyspnea amplifies dyspnea perception and fear, especially in individuals with high levels of FoS. These effects were unrelated to respiratory neural gating or physiological fear responses, requiring future studies on underlying mechanisms.

Electrophysiological Evidence of Event-Related Potential Changes Induced by 12 h Abstinence in Young Smokers Based on the Flanker Study

The cognitive control processes may be disrupted by abstinence in smokers, which may be helpful in the development and maintenance of addictive behavior. The purpose of this study was to measure the performance of cognitive task after 12 h of smoking abstinence by using event-related potentials (ERPs), including the error-related negativity (ERN) and the error positivity (Pe). In Eriksen flanker task, electroencephalography (EEG) signals of 24 smokers were recorded in two conditions: satiety and 12 h abstinence. In the behavioral data, both conditions exhibited more errors and more time on the incongruent trials than congruence. Meantime, the Minnesota Nicotine Withdrawal Scale (MNWS) score was increased during abstinence. Smokers showed reduced ERN and Pe after 12 h of abstinence, compared with satiety condition. The results indicate that the diminished error processing in young smokers after 12 h of abstinence. It may be related to increased withdrawal symptoms. In conclusion, the disrupted neurophysiological indexes in the general behavior monitoring system may be caused by abstinence. The results of this study may provide us with new ideas about the effects of short-term abstinence on brain cognitive neuroscience and be helpful for the solution of relapse.

The Effects of Repeated Dyspnea Exposure on Response Inhibition

In order to treat dyspnea (=breathlessness) successfully, response inhibition (RI) as a major form of self-regulation is a premise. This is supported by research showing that self-regulation is associated with beneficial behavioral changes supporting treatment success in patients. Recent research showed that dyspnea has an impairing effect on RI, but the effects of repeated dyspnea exposure on RI remain unknown. Therefore, the present study tested the effects of repeated resistive load-induced dyspnea on RI over a 5-day period. Healthy volunteers (n = 34) performed the standard version of the Stroop task during baseline and dyspnea conditions on the first and fifth testing day and underwent an additional dyspnea exposure phase on each testing day. Variables of interest to investigate RI were reaction time, accuracy as well as the event-related potentials late positive complex (LPC) and N400 in the electroencephalogram. Reduced accuracy for incongruent compared to congruent stimuli during the dyspnea condition on the first testing day were found (p < 0.001). This was paralleled by a reduced LPC and an increased N400 for incongruent stimuli during the induction of dyspnea (p < 0.05). After undergoing dyspnea exposure, habituation of dyspnea intensity was evident. Importantly, on the fifth testing day, no differences between baseline, and dyspnea conditions were found for behavioral and electrophysiological measures of RI. These findings demonstrate that the impairing effect of dyspnea on RI disappeared after repeated dyspnea exposure in healthy participants. Translated to a clinical sample, it might cautiously be suggested that dyspnea exposure such as dyspnea perceived during physical exercise could reduce the impairing effect of dyspnea on RI which might have the potential to help increase self-regulation abilities and subsequent treatment efforts in dyspneic patients.

The Impact of Unpredictability on Dyspnea Perception, Anxiety and Interoceptive Error Processing

Dyspnea is a prevalent interoceptive sensation and the aversive cardinal symptom in many cardiorespiratory diseases as well as in mental disorders. Especially the unpredictability of the occurrence of dyspnea episodes has been suggested to be highly anxiety provoking for affected patients. Moreover, previous studies demonstrated that unpredictable exteroceptive stimuli increased self-reports and electrophysiological responses of anxiety such as the startle probe N100 as well as amplified the processing of errors as reflected by greater error-related negativity (ERN). However, studies directly examining the role of unpredictability on dyspnea perception, anxiety, and error processing are widely absent. Using high-density electroencephalography, the present study investigated whether unpredictable compared to predictable dyspnea would increase the perception of dyspnea, anxiety and interoceptive error processing. Thirty-two healthy participants performed a respiratory forced choice reaction time task to elicit an interoceptive ERN during two conditions: an unpredictable and a predictable resistive load-induced dyspnea condition. Predictability was manipulated by pairing (predictable condition) or not pairing (unpredictable condition) dyspnea with a startle tone probe. Self-reports of dyspnea and affective state as well as the startle probe N100 and interoceptive ERN were measured. The results demonstrated greater dyspnea unpleasantness in the unpredictable compared to the predictable condition. Post hoc analyses revealed that this was paralleled by greater anxiety, and greater amplitudes for the startle probe N100 and the interoceptive ERN during the unpredictable relative to the predictable condition, but only when the unpredictable condition was experienced in the first experimental block. Furthermore, higher trait-like anxiety sensitivity was associated with higher ratings for dyspnea unpleasantness and experimental state anxiety ratings. The present findings suggest that unpredictability increases the perception of dyspnea unpleasantness. This effect seems related to increased state and trait anxiety and interoceptive error processing, especially when upcoming dyspnea is particularly unpredictable, such as in early experimental phases. Future studies are required to further substantiate these findings in patients suffering from dyspnea.