Improvisation and live accompaniment increase motor response and reward during a music playing task

What is the central question of this study? A transcranial magnetic stimulation (TMS)-induced twitch applied on isolated single breaths over the motor cortex somatotopic representation of the tongue briefly recruits submental muscles and improves airflow dynamics of flow-limited respiratory cycles without arousing sleep apnoea patients. However, the mechanical impact of the TMS-induced twitch applied during consecutive breathing cycles on airflow dynamics remains unknown. What is the main finding and what is its importance? Our results show that application of TMS with the stimulator output set at the sleep submental motor threshold intensity on consecutive respiratory cycles increases inspiratory flow and reduces the turbulent airflow component. These results indicate an improvement of airflow pattern after two single consecutive TMS-induced twitches without arousing sleep apnoea patients. Transcranial magnetic stimulation (TMS)-induced twitches applied on isolated breaths briefly recruit upper airway dilator muscles and improve airflow and inspiratory volume without arousing apnoeic patients from sleep, but the effects of applying such twitches consecutively on airflow dynamics is unknown. The objective of this study was to quantify the effects of five consecutive TMS-induced twitches applied on sleep-induced obstructive hypopnoeic breaths in 10 obstructive sleep apnoea patients. Submental muscle motor threshold (SUBMT) and motor-evoked potential were measured during wakefulness and sleep. The TMS-induced twitches were applied during stable non-rapid eye movement (NREM) sleep, at the beginning of inspiration of consecutive flow-limited respiratory cycles, with the stimulator output set at sleep SUBMT. Maximal inspiratory flow, inspiratory volume, inspiratory time, shifts of electroencephalogram frequency and pulse rate variability were assessed. During sleep, SUBMT increased (wakefulness, 25.3 ± 4.9%; NREM sleep, 27.0 ± 6.2%; P = 0.02). During each series of stimulations there was a rise in maximal inspiratory flow (from 306.7 ± 123.2 to 359.8 ± 154.1 ml s(-1); P = 0.0002) and in inspiratory volume (from 346.1 ± 128.1 to 414.9 ± 171.2 ml; P = 0.02) without differences in thoraco-abdominal efforts and inspiratory time. These responses were observed in the absence of arousals and ceased immediately after TMS interruption. Transcranial magnetic stimulation-induced cortical and/or autonomic arousal was observed in 30.2% of all series of stimulation. Consecutive twitch TMS of submental muscles may lead to arousals in a minority of patients but can be applied on consecutive respiratory cycles during sleep and can significantly improve maximal inspiratory flow and inspiratory volume of flow-limited cycles.

Breathing is a complex, vital function that can be modulated to influence physical and mental well-being. However, the role of cortical and subcortical brain regions in voluntary control of human respiration is underexplored. Here we investigated the influence of damage to human frontal, temporal or limbic regions on the sensation and regulation of breathing patterns. Participants performed a respiratory regulation task across regular and irregular frequencies ranging from 6 to 60 breaths per minute (bpm), with a counterbalanced hand motor control task. Interoceptive and affective states induced by each condition were assessed via questionnaire, and autonomic signals were indexed via skin conductance. Participants with focal lesions to the bilateral frontal lobe, right insula/basal ganglia and left medial temporal lobe showed reduced performance relative to individually matched healthy comparisons during the breathing and motor tasks. They also reported significantly higher anxiety during the 60bpm regular and irregular breathing trials, with anxiety correlating with difficulty in rapid breathing specifically within this group. This study demonstrates that damage to frontal, temporal or limbic regions is associated with abnormal voluntary respiratory and motor regulation and tachypnoea-related anxiety, highlighting the role of the forebrain in affective and motor responses during breathing. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.

Background: Peritraumatic dissociation is purported to emerge together with attenuated autonomic arousal, immobility, and staring. However, empirical evidence is scarce and heterogeneous. Moreover, it is still a matter of debate whether these responses predict intrusion formation. Objective: The present trauma-analogue study examined associations between peritraumatic dissociation, autonomic activation, facial movements, staring, and intrusion formation. Method: Seventy-one healthy women watched a highly aversive film, while autonomic activation (heart rate, respiratory sinus arrhythmia, skin conductance level), facial movements (temporal variations in corrugator electromyography), and staring (fixation duration, tracklength) were assessed. Afterwards, participants rated the intensity of dissociation during film viewing and reported intrusions and associated distress in a smartphone application for 24 hours. Results: Peritraumatic dissociation was linked to higher autonomic arousal (higher heart rate and, on a trend-level, lower respiratory sinus arrhythmia), increased facial movements, and staring (lower tracklength). Peritraumatic dissociation, higher autonomic arousal (higher heart rate and lower respiratory sinus arrhythmia), staring (higher fixation duration), and, on a trend-level, more facial movements were linked to higher intrusion load (number x distress of intrusions) and together explained 59% of variance. Skin conductance level was neither linked to peritraumatic dissociation nor intrusion load. Conclusions: Our results suggest that, at low-dissociation-levels observed in trauma-analogue studies, peritraumatic dissociation may occur together with heightened autonomic arousal and facial movements, indexing increased negative affect. Staring might, irrespectively of dissociation-levels, serve as objective marker for dissociation. Together, peritraumatic dissociation and its psychophysiological correlates might set the stage for later intrusion formation.

Injured athletes' psychological distress has been explored using a stress-response paradigm and through a variety of research methodologies. Despite growing interest in psychophysiological stress-response research (Gatchel, 1997), physiological features of psychological distress have not yet been explored among injured athletes (Flint, 1998). Psychological distress has been associated with delayed healing among other medical populations (Kiecolt-Glaser, Page, Marucha, MacCallum, & Glaser, 1998), and physiological features of distress have lead to increased reports of a variety of health-related problems (Baum, Gatchel, & Krantz, 1997). The present research consists of two studies designed to validate preliminary reports and advance current knowledge regarding the presence of posttraumatic distress among injured athletes through sampling younger athletes and utilizing psychophysiological indices of distress. In the first study, high school athletes (n = 162) reported frequency of experiencing two common cognitive-affective and behavioral features of posttraumatic distress, intrusive thoughts and avoidance behavior. ANOVA indicated that athletes who had incurred injuries the previous year experienced greater frequency of intrusive thoughts and avoidance behavior regarding prior injuries than athletes who had not incurred injuries the prior year. In the second study, Varsity male athletes (n = 7) who incurred a severe injury within the past 2 years and matched controls (n = 5) were compared on both psychological and physiological indices of distress. Specifically, injured and non-injured athletes' self-reported distress and autonomic arousal, as measured by heart rate and electrodermal activity, in response to a series of injury and non-injury-related video clips was measured. A priori planned contrast analyses revealed that injured athletes' had a greater degree of physiological reactivity and experienced more subjective distress than non-injured controls, and reactivity was greatest during injury-related stimuli than during non-injury or neutral stimuli. Correlation analyses indicated that athletes' self-reported and physiological responses were related. Results are discussed in relation to existing literature regarding the nature of athletes' post-injury response as well as provide novel information regarding athletes' physiological reactivity to stimuli indicative of the competitive sport environment to which they must return following a severe injury.

The way in which the tendency to fear somatic arousal sensations (anxiety sensitivity), in interaction with the created expectations regarding arousal induction, might affect defensive responding to a symptom provocation challenge is not yet understood. The present study investigated the effect of anxiety sensitivity on autonomic arousal, startle eyeblink responses, and reported arousal and alertness to expected vs. unexpected caffeine consumption. To create a match/mismatch of expected and experienced arousal, high and low anxiety sensitive participants received caffeine vs. no drug either mixed in coffee (expectation of arousal induction) or in bitter lemon soda (no expectation of arousal induction) on four separate occasions. Autonomic arousal (heart rate, skin conductance level), respiration (end-tidal CO2, minute ventilation), defensive reflex responses (startle eyeblink), and reported arousal and alertness were recorded prior to, immediately and 30 min after beverage ingestion. Caffeine increased ventilation, autonomic arousal, and startle response magnitudes. Both groups showed comparable levels of autonomic and respiratory responses. The startle eyeblink responses were decreased when caffeine-induced arousal occurred unexpectedly, e.g., after administering caffeine in bitter lemon. This effect was more accentuated in high anxiety sensitive persons. Moreover, in high anxiety sensitive persons, the expectation of arousal (coffee consumption) led to higher subjective alertness when administering caffeine and increased arousal even if no drug was consumed. Unexpected symptom provocation leads to increased attention allocation toward feared arousal sensations in high anxiety sensitive persons. This finding broadens our understanding of modulatory mechanisms in defensive responding to bodily symptoms.

This exploratory study aimed to deepen our understanding of relational and embodied processes implicated in psychotherapy, by examining the association of alliance ruptures with therapeutic dyad’s autonomic arousal during psychotherapy sessions. A central assumption of the study was that the therapeutic alliance is a core and dynamic aspect of therapy process, shaped by the mutual influence of therapist and client on both verbal/explicit and embodied/implicit levels. The research material consisted of 12 video-recorded sessions drawn from seven psychodynamic therapy cases; it included data regarding the activation of the autonomic nervous system, as reflected in the Absolute Stress Vector, an index derived from heart-rate measurements, and ruptures in the therapeutic alliance, as coded by the Rupture Resolution Rating System. A multilevel model (MLM) was applied to explore possible relationships between autonomic arousal and the specific type of rupture (no rupture, withdrawal, confrontation, mixed). The MLM showed that clients displayed higher autonomic arousal during periods of mixed ruptures compared to periods of no rupture, of confrontation and withdrawal rupture; and lower arousal during episodes of confrontation ruptures as compared to periods of no rupture. Based on this exploratory study, mixed ruptures seem to reflect a distinct pattern of disaffiliation in the therapeutic relationship and which merits further investigation in relation to its contribution to the therapy process.

Rating of perceived exertion (RPE) and affective responses are important aspects of the exercise experience. Limited research suggests that exercise intensity may be important in the formation of the overall view of the exercise experience. PURPOSE: Determine the impact of varying the intensity of an exercise bout relative to the ventilatory threshold on RPE, affect, and self-efficacy. METHODS: Eight participants (6 male, 2 female, mean age = 24 years) were tested for aerobic fitness to determine VO2max (mean = 49 ml × kg-1 × min-1). Participants completed five 30-minute trials of treadmill exercise prescribed to be equivalent in terms of external work and distance travelled. Each trial differed with respect to the variation of the workload: 1) steady throughout, 2) increasing, 3) decreasing, 4) peak in middle, and 5) valley in middle. All workload changes occurred at the 10 and 20 minute marks of the trial. Measures of RPE, affect, arousal, and heart rate (HR) were taken before, every five minutes during, immediately after, and 15 minutes after exercise. Enjoyment and self-efficacy were assessed immediately and 15 minutes after exercise. RESULTS: Data were analyzed using ANOVA and pairwise comparisons. No differences were noted for anticipated or post-exercise RPE (P > 0.05), despite numerous differences in RPE and HR during exercise (P < 0.05). Similarly, no differences were noted for post-exercise ratings of exercise self-efficacy (P > 0.05). Several differences were noted within the affective data including lower post-exercise affect scores in the trial with reduced effort in the middle and higher post-exercise enjoyment in the trial with greatest effort in the middle (P < 0.05). Several other comparisons trended toward significance but did not reach acceptable alpha levels due in part to lack of statistical power. CONCLUSIONS: Findings suggest that variations in intensity during trials of exercise sufficient to induce significant in-task differences in HR and RPE do not impact post-exercise RPE. This data also suggests that affective and enjoyment responses post-exercise can be impacted by within trial variations in exercise intensity. However, more research is needed in larger and more diverse samples to more fully understand how varied exertion during exercise impacts post-exercise perceptions.

Cognitive load and autonomic arousal are hypothesized to affect voice production, yet the nature of these relationships is unclear. The purpose of this study was to assess how cognitive load and autonomic arousal differentially affect voice production and vocal motor control. Physiological measures of autonomic arousal were recorded from 30 adults under different cognitive loads elicited by a Stroop task. In Experiment 1, voice acoustic measures were measured during speech production. In Experiment 2, fundamental frequency (fo) responses to predictably altered auditory feedback (sensorimotor adaptation) were measured. Mixed linear-effects models assessed relationships between variables. Changes between cognitive loads were compared among the two experiments. In Experiment 1, increased cognitive load was associated with increases in sound pressure level, whereas increases in autonomic arousal measures (i.e., decreases in skin conductance rise time, pulse amplitude, and period) were related to decreases in cepstral peak prominence. Increased autonomic arousal (i.e., decreased pulse amplitude) was related to increased adaptation in Experiment 2. Participants who responded to increased cognitive load by decreasing fo during Experiment 1 showed more adaptation in Experiment 2. Differential effects of cognitive load and autonomic arousal emphasize the importance of individual physiological variability when assessing how stress affects the voice.

Response perseveration is the tendency to continue a response set for reward despite punishment. In the present study, response perseveration and sensitivity to reward and punishment were assessed in boys with oppositional defiant disorder (ODD). The study also examined the relation between punishment sensitivity and autonomic arousal. Nineteen ODD boys (mean age 9.8 years) and 20 normal control boys (NC) (mean age 9.7 years) were administered the door-opening task. In this task, the subject chooses either to open the next door or to stop playing; the opening of doors is initially rewarded and then increasingly punished. ODD boys opened more doors than NC boys. Following punishment, ODD boys took less time than NC boys before opening the next door, but did not differ from NC boys in time after reward. Mean skin conductance level was lower in ODD boys than in NC boys. The correlation coefficient between time after punishment and skin conductance level was moderately positive in the total sample. These results suggest that response perseveration in ODD boys is related to low punishment sensitivity and that skin conductance level is a marker of punishment sensitivity.

Influence of sympathetic autonomic arousal on cortical arousal: implications for a therapeutic behavioural intervention in epilepsy

Human grip is commonly used in sport and recreational activities and involves the coordinated activation of forearm muscles. Lateral epicondylalgia (LE) is a common musculoskeletal disorder that involves pathology of the tendon of extensor carpi radialis brevis (ECRB) at its insertion onto the lateral epicondyle of the humerus. LE presents clinically as pain provoked by gripping activities and has a major impact on function. This results in days off work and time off sport. Despite considerable research into the pathophysiology of LE, it remains poorly understood whether forearm muscles activity is altered during gripping in individuals with LE. This thesis aimed to comprehensively understand the extent of current knowledge and provide new data of activity of the wrist/forearm muscles in LE. Study 1 clarifies the current understanding of muscle activity in LE by way of systematic review with quantitative analysis. This review identified that studies of individuals with LE revealed altered motor unit morphology, abnormal patterns of muscle activity during resisted wrist extension and tennis strokes, fewer cortical peaks and less distance between cortical representation of muscles (mapped with transcranial magnetic stimulation), and delayed activation of wrist extensor muscles during gripping, when contrasted to pain-free controls. The latter finding was also present on the asymptomatic limb. Importantly, this systematic review identified limited understanding of gripping despite the clinical importance of this task in provocation of LE. The only study that had investigated muscle activity during this task had severe limitations that compromise the interpretation of the results. Limitations included the use of surface electromyography (which does not record from individual muscles), and performance of sustained contraction with high grip force (50% maximum voluntary contraction), which is likely to be provocative of pain in some individuals with LE. On the basis of some evidence of sensorimotor changes in the asymptomatic limb of individuals with unilateral LE, Study 2 was conducted as a systematic review with meta-analysis to determine the extent bilateral differences in sensorimotor function between individuals with unilateral tendinopathy and pain-free controls. Study 2 identified evidence for several sensory and motor system differences, and evidence for tendon pathology in the asymptomatic limb of individuals with other unilateral tendinopathies (Achilles tendinopathy) but not LE when contrasted to pain-free controls. On the foundation that tendon pathology was present in asymptomatic limb of individuals with Achilles tendinopathy, Study 3 investigated whether there was a greater prevalence of tendon pathology of the asymptomatic common extensor tendon of individuals with LE than pain-free controls. Unlike the findings in the Achilles tendon, Study 3 did not identify greater tendon pathology in the asymptomatic limb of individuals with unilateral LE than that present in the tendons of pain-free individuals. As no studies had explored specific muscle activation during a low level grip, Study 4 compared the contribution of forearm muscle activity to gripping between the symptomatic and asymptomatic sides in individuals with unilateral LE and pain-free individuals. This study highlighted altered muscle activity in LE characterised by a lower contribution of ECRB in the symptomatic arm and a greater contribution of extensor digitorum communis (EDC) and flexor digitorum profundus (FDP) to total EMG bilaterally, in individuals with LE than pain-free individuals. Modified distribution of activity between the synergist wrist extensor muscles ECRB and EDC has potential to impact on the functional performance of grip. The strategy used by individuals with might compromise efficient grip as finger flexor muscles (FDP) would need to overcome finger extensor muscle activity (EDC). Although potentially negative for grip, the different motor pattern could have consequences for ECRB pathology by unloading the muscle. This could provide a benefit of pain reduction, but also potential negative effects from stress shielding of the tendon. Study 5 investigated potential differences in muscle synergies (defined as groups of muscles working together to simplify central nervous system processing) between individuals with LE and pain-free individuals. For both groups, analysis with non-negative matrix factorization identified two muscle synergies involved in control of forearm muscles during repetitive gripping. Comparison between groups indicated the variance accounted for by the muscle synergies was lower in the LE group than pain-free individuals, which suggests more variation in muscle activation pattern for that group. The studies outlined in this thesis identified differences in the control of forearm muscles between individuals with and without LE. The findings imply that EDC provides a greater contribution and ECRB a lesser contribution to the gripping task in individuals with LE than pain-free controls. Given the cross-sectional study design it is not possible to clarify whether the differences preceded or followed LE, but in both cases rehabilitation of muscle activation is likely to be beneficial for recovery. Clinical interventions to modify forearm muscle activity may provide clinical benefit, but future research is needed to determine whether altered muscle activity can be changed and whether this improves outcomes.

SIR–Our recent review on the effect of surgery of the spastic hand of children with cerebral palsy (CP) indicated that only studies with a low level of evidence were available, i.e. series of cases.1 The existing information indicated that surgery seems to have a positive effect on supination and dorsiflexion of the wrist, may improve grip strategy, and may induce an increase of the repertoire of grips and spontaneous use of the hand. The effect of surgery of the spastic hand on muscle coordination had only been addressed by three studies in a relatively systematic way.2–4 Unfortunately, it remained unclear, whether the putatively better hand function was the result of a better positioning of the hand and fingers and/or changes in muscle coordination induced by tendon transfer. Therefore, we started a pilot study in order to obtain insight into changes in muscle coordination and quality of reaching movements after surgical muscle transfers of the upper extremity in adolescents with unilateral CP. We hypothesised that surgery would result in more coordinated and more efficient muscle recruitment, i.e. in lower muscle activation rates, a reduction in recruitment of all arm muscles in concert, and in a temporal coordination which more closely resembles that of typically developing adolescents.4–7 In addition we evaluated whether surgery would result in qualitative improvement of motor behaviour during reaching. Three adolescents with unilateral CP who had surgery for their spastic hand to improve grip strategy and functional use of the paretic hand were studied. Hand posture, movement quality, and muscle coordination during a simple reaching task were assessed preoperatively and three times during the first postoperative year. Six age-matched typically developing adolescents had a single assessment to attain normative electromyography (EMG) data. Surgical procedures and patient characteristics are summarized in Table I.8–10 Postoperative treatment consisted of 5 weeks plaster immobilization, followed by a period of 6 weeks during which a removable splint was worn and intensive occupational therapy was applied. EMG was recorded continuously with bipolar surface electrodes of the following muscles: biceps brachii, triceps brachii, wrist extensors, and wrist flexors. A computer algorithm was used for the detection of phasic muscle activity.11 The analysis focused on (1) muscle activation rate, i.e. percentage of trials during which a muscle was activated; (2) ‘In concert’ muscle activation rate, i.e. percentage of trials during which all muscles were recruited; (3) percentage of trials during which a specific muscle was the ‘prime mover’; (4) onset latency of muscle activation; and (5) sequence of muscle activation: percentage of trials during which the sequence of activation consisted of (a) wrist Extensors, (b) biceps Brachii, and (c) wrist Flexors (EBF-sequence). The participants and their parents gave written informed consent and the procedures were approved by the ethics committee of the University Medical Center in Groningen. The operated hand showed in all three participants at 3 to 12 months postoperatively improvement in hand position and movement quality of wrist and fingers. This finding is in agreement with literature reports.12–15 The EMG-data indicated that surgery did not affect the rate of isolated or in concert muscle recruitment, the nature of the ‘prime mover’, or onset latencies. It did however affect muscle recruitment order: the atypical EBF-recruitment order decreased from 55% prior to surgery to 30%, 10%, and 10% at 3, 6, and 12 months respectively after the operation (Friedman: p=0.04. Fig. 1). Wrist Extensors, biceps Brachii, and wrist Flexors. (EBF)-sequence of non-dominant extremity of typically developing adolescents and adolescents with cerebral palsy pre -and post-operative. The findings of this pilot study suggest that surgery of the spastic hand does not only result in improved hand position, but also in a better quality of wrist and finger movements and a reduction of an atypical recruitment order of arm muscles. The latter may indicate that improved hand position may improve a person’s capacity to select a more efficient strategy out of the motor repertoire.5 Further investigation into the functional consequences of surgery of the spastic hand is highly recommended.

Sleep's contribution to affective regulation is insufficiently understood. Previous human research has focused on memorizing or rating affective pictures and less on physiological affective responsivity. This may result in overlapping definitions of affective and declarative memories and inconsistent deductions for how rapid eye movement sleep (REMS) and slow-wave sleep (SWS) are involved. Literature associates REMS theta (4–8 Hz) activity with emotional memory processing, but its contribution to social stress habituation is unknown. Applying selective sleep stage suppression and oscillatory analyses, we investigated how sleep modulated affective adaptation toward social stress and retention of neutral declarative memories. Native Finnish participants (N = 29; age, M = 25.8 years) were allocated to REMS or SWS suppression conditions. We measured physiological (skin conductance response, SCR) and subjective stress response and declarative memory retrieval thrice: before laboratory night, the next morning, and after 3 d. Linear mixed models were applied to test the effects of condition and sleep parameters on emotional responsivity and memory retrieval. Greater overnight increase in SCR toward the stressor emerged after suppressed SWS (intact REMS) relative to suppressed REMS (20.1% vs 6.1%; p = 0.016). The overnight SCR increase was positively associated with accumulated REMS theta energy irrespective of the condition (r = 0.601; p = 0.002). Subjectively rated affective response and declarative memory recall were comparable between the conditions. The contributions of REMS and SWS to habituation of social stress are distinct. REMS theta activity proposedly facilitates the consolidation of autonomic affective responses. Declarative memory consolidation may not have greater dependence on intact SWS relative to intact REMS.

Soft exosuits offer promise to support users in everyday workload tasks by providing assistance. However, acceptance of such systems remains low due to the difficulty of control compared with rigid mechatronic systems. Recently, there has been progress in developing control schemes for soft exosuits that move in line with user intentions. While initial results have demonstrated sufficient device performance, the assessment of user experience via the cognitive response has yet to be evaluated. To address this, we propose a soft pneumatic elbow exosuit designed based on our previous work to provide assistance in line with user expectations utilizing two existing state-of-the-art control methods consisting of a gravity compensation and myoprocessor based on muscle activation. A user experience study was conducted to assess whether the device moves naturally with user expectations and the potential for device acceptance by determining when the exosuit violated user expectations through the neuro-cognitive and motor response. Brain activity from electroencephalography (EEG) data revealed that subjects elicited error-related potentials (ErrPs) in response to unexpected exosuit actions, which were decodable across both control schemes with an average accuracy of 76.63 ± 1.73% across subjects. Additionally, unexpected exosuit actions were further decoded via the motor response from electromyography (EMG) and kinematic data with a grand average accuracy of 68.73 ± 6.83% and 77.52 ± 3.79% respectively. This work demonstrates the validation of existing state-of-the-art control schemes for soft wearable exosuits through the proposed soft pneumatic elbow exosuit. We demonstrate the feasibility of assessing device performance with respect to the cognitive response through decoding when the device violates user expectations in order to help understand and promote device acceptance.

Stability analysis of the elbow with a load