Exploring Fatigue Effects on Performance Variation of Intensive Brain–Computer Interface Practice

Motor imagery (MI) is an endogenous mental process and is commonly used as an electroencephalogram (EEG)-based brain–computer interface (BCI) strategy. Previous studies of P300 and MI-based (without online feedback) BCI have shown that mental states like fatigue can negatively affect participants’ EEG signatures. However, exogenous stimuli cause visual fatigue, which might have a different mechanism than endogenous tasks do. Furthermore, subjects could adjust themselves if online feedback is provided. In this sense, it is still unclear how fatigue affects online MI-based BCI performance. With this question, 12 healthy subjects are recruited to investigate this issue, and an MI-based online BCI experiment is performed for four sessions on different days. The first session is for training, and the other three sessions differ in rest condition and duration—no rest, 16-min eyes-open rest, and 16-min eyes-closed rest—arranged in a pseudo-random order. Multidimensional fatigue inventory (MFI) and short stress state questionnaire (SSSQ) reveal that general fatigue, mental fatigue, and distress have increased, while engagement has decreased significantly within certain sessions. However, the BCI performances, including percent valid correct (PVC) and information transfer rate (ITR), show no significant change across 400 trials. The results suggest that although the repetitive MI task has affected subjects’ mental states, their BCI performances and feature separability within a session are not affected by the task significantly. Further electrophysiological analysis reveals that the alpha-band power in the sensorimotor area has an increasing tendency, while event-related desynchronization (ERD) modulation level has a decreasing trend. During the rest time, no physiological difference has been found in the eyes-open rest condition; on the contrary, the alpha-band power increase and subsequent decrease appear in the eyes-closed rest condition. In summary, this experiment shows evidence that mental states can change dramatically in the intensive MI-BCI practice, but BCI performances could be maintained.

Thenar Muscle Motor Imagery Increases Spinal Motor Neuron Excitability of the Abductor Digiti Minimi Muscle

When a person attempts intended finger movements, unintended finger movement also occur, a phenomenon called “enslaving”. Given that motor imagery (MI) and motor execution (ME) share a common neural foundation, we hypothesized that the enslaving effect on the spinal motor neuron excitability occurs during MI. To investigate this hypothesis, electromyography (EMG) and F-wave analysis were conducted in 11 healthy male volunteers. Initially, the EMG activity of the left abductor digiti minimi (ADM) muscle during isometric opposition pinch movement by the left thumb and index finger at 50% maximal effort was compared with EMG activity during the Rest condition. Next, the F-wave and background EMG recordings were performed under the Rest condition, followed by the MI condition. Specifically, in the Rest condition, subjects maintained relaxation. In the MI condition, they imagined isometric left thenar muscle activity at 50% maximal voluntary contraction (MVC). During ME, ADM muscle activity was confirmed. During the MI condition, both F-wave persistence and the F-wave/M-wave amplitude ratio obtained from the ADM muscle were significantly increased compared with that obtained during the Rest condition. No difference was observed in the background EMG between the Rest and MI conditions. These results suggest that MI of isometric intended finger muscle activity at 50% MVC facilitates spinal motor neuron excitability corresponding to unintended finger muscle. Furthermore, MI may induce similar modulation of spinal motor neuron excitability as actual movement.

Impacts of different intensities of exercise on inflammation and hypoxia markers in low altitude

Background This study aims to determine and compare the effects of exercise modalities with different intensities on the secretion of key inflammation and hypoxia markers in amateur athletes. Methods Twenty-three athletes with a mean age of 20.1 years, living at low altitude (1850 m) participated in this study. The participants' maximal oxygen consumption values (VO2 max) were determined with an incremental cycle exercise test as 54.15 ± 6.14 mL kg min−1. Athletes performed four protocols: at rest, 50% VO2 max, 75% VO2 max and 100% VO2 max (until exhaustion) with one-week intervals. 50% VO2 max, 75% VO2 max sessions were performed continuously for 30 min on a bicycle ergometer and 100% VO2 max session was performed by cycling until exhaustion. Blood samples were obtained at rest and immediately after each exercise session. Serum tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), interleukin-10 (IL-10), and hypoxia inducible factor-1 alpha (HIF-1α) levels were measured. Results There were significant differences in serum TNF-α levels in 75% VO2 max and 100% VO2 max sessions (489.03 ± 368.37 and 472.70 ± 365.21 ng/L, respectively) compared to rest conditions (331.65 ± 293.52 ng/L). Serum CRP levels of 50% VO2 max and 75% VO2 max sessions (1.19 ± 0.50; 1.07 ± 0.52 mg/L) were significantly higher than the rest condition (0.74 ± 0.35 mg/L). There were significant differences in serum IL-10 levels of rest condition and 50% VO2 max; 50% VO2 max, and 100% VO2 max sessions (328.09 ± 128.87; 446.36 ± 142.84; 347.44 ± 135.69; 324.88 ± 168.06 pg/mL). Serum HIF-1α levels were significantly higher in 75% VO2 max session compared to rest (1.26 ± 0.16; 1.08 ± 0.19 ng/mL) (P < 0.05 for all comparisons). Conclusions Both inflammatory and anti-inflammatory pathway is induced on different exercise intensities. Exercise protocols performed until exhaustion may lead to activation of inflammatory pathways and hypoxia-induced damage.

Emotional Distraction by Constant Finger Tapping

This study examined the effects of emotional distraction in the context of recalling stressful interpersonal events in daily life. Previous studies have revealed that distraction decreases unpleasant emotions. In this study, we examined whether distraction tasks decrease unpleasant task-related thoughts in addition to unpleasant emotions. Furthermore, to investigate the implicit effects of emotional changes, we examined changes in pupil size in relation to unpleasant emotions and task-unrelated thoughts (TUT). The behavioral tasks were administered to 21 university students ( Mage = 21.24 ± 2.93 years; range: 18–30 years). After excluding participants for poor data quality, 16 (21.31 ± 3.34 years; 18–30 years) were included for further pupil data analysis. As an emotion induction procedure, participants were asked to freely recall memories of stressful interpersonal events in their daily lives and were given a series of questions about their recalled memories, which were presented on the monitor. In the following distraction experiment, questions during the emotion induction procedure were represented as emotional stimulation; a distraction task (non-constant or constant finger tapping) or rest condition was then performed; subsequently, ratings were given for attentional state, thought types conceived during the tasks, and emotional state. Upon analysis, differences in the ratings for unpleasant emotion and TUT were non-significant between all conditions. Nevertheless, pupil dilation in the non-constant and constant conditions was associated with decreased unpleasant emotions ( p < .05; p < .05 to .01). More importantly, pupil dilation was associated with decreased unpleasant TUT ( p < .05) only in the constant condition. Although the observed effects were subtle, we found that constant finger tapping decreased unpleasant emotions and TUT. It is expected for a future emotion regulation study to further investigate the effects in the relationships among emotions, thoughts, and physiological states, which can help in coping with unpleasant emotions.

Breaking up prolonged sitting with a 6 min walk improves executive function in women and men esports players: a randomised trial

ObjectiveThe effect of prolonged sitting on executive function and performance in competitive esports players are unknown. This study aimed to evaluate executive function following a 6 min bout of walking or rest during prolonged gaming in competitive esports players.Methods12 men and 9 women completed three separate 2-hour gaming session days assigned in randomised order consisting of a 6 min walk break, 6 min rest break and continuous before and after each session. Postintervention participant exit survey data were also collected.ResultsThe walk condition produced a significantly faster mean solution time (7613.6±3060.5 min, p=0.02) and planning time (5369.0±2802.09, p=0.04) compared with the resting condition (9477±3547.4; 6924±3247.7) and continuous play (8200.0±3031.6; 5862.7±2860.7). The rest condition resulted in the slowest mean solution time (9477.0±3547.4) and planning time (6924.0±3247.7), with the continuous play resulting in a faster mean solution time (8200.1±3031.6) and planning time (5862.7±2860.7) than the rest condition. There was no impact on game performance in any of the conditions. However, over 70% of participants felt that the walk break improved esports performance.ConclusionsReducing sit time and breaking up prolonged sitting have acute and chronic health benefits. This study provides evidence that a 6 min walking break in the middle of 2 hours of gameplay allows gamers to have these health benefits while improving processing speed and executive function.Trial registration numberNCT04674436.

Energy Intake and Appetite Sensations Responses to Aquatic Cycling in Healthy Women: The WatHealth Study

Background: The aim of this study was to investigate energy expenditure, food intake and appetite feelings in response to water- vs. land-based cycling exercises in healthy young women. Methods: Anthropometric measurements and body composition were assessed among 20 women who performed four experimental sessions in a randomized order: (i) a rest condition (CONT); (ii) a 30-min aqua-cycling exercise session (WAT), (iii) a 30-min land-cycling exercise session at the same rpm (LAND), (iv) a land-cycling session at the same heart rate and isoenergetic to WAT (LAND-Iso). Energy expenditure and substrate oxidation were measured by indirect calorimetry; ad libitum energy intake during subsequent lunch was assessed with appetite feelings recorded at regular intervals. Results: Energy expenditure was higher during the 30-min WAT than during CONT and LAND (p < 0.001). Carbohydrate oxidation was higher in the WAT session compared to CONT and LAND (p < 0.05). LAND-Iso duration was significantly increased (+14 min) to reach the same energy expenditure as in the WAT condition (p < 0.05). There was no differences in food intake between sessions. Conclusion: While further studies are needed to optimize the chronic energetic effects of aqua-cycling, the present study suggests that this exercise modality could represent an efficient strategy to induce acute energy deficit.

Adults with autism spectrum disorder show atypical patterns of thoughts and feelings during rest

Mind wandering constitutes a major part of everyday experience and is inherently related to how we feel and identify ourselves. Thus, probing the character and content of thoughts and feelings experienced during mind-wandering episodes could lead to a better understanding of the human mind in health and disease. How mind wandering and spontaneous thought processes are affected in disorders such as autism is poorly understood. Here, we used the eyes-closed rest condition to stimulate mind wandering and quantified the subjective experiences using the Amsterdam Resting-State Questionnaire—which quantifies subjective psychological states of resting-state cognition across 10 domains—in 88 adults with autism spectrum disorder and 90 controls. We observed an atypical pattern of both thoughts and feelings in the autism spectrum disorder cohort, specifically in the domains of Theory of Mind, Comfort, and Discontinuity of Mind. We propose that the use of the Amsterdam Resting-State Questionnaire as a standardized cognitive instrument could advance our understanding of thoughts and feelings in autism spectrum disorder as well as in a wide variety of other brain disorders and how these may change due to therapeutic interventions. Lay abstract Everyone knows the feeling of letting one’s mind wander freely in a quiet moment. The thoughts and feelings experienced in those moments have been shown to influence our well-being—and vice versa. In this study, we looked at which thoughts and feelings are being experienced by adults with autism spectrum disorder and compared them to adults without autism spectrum disorder. In total, 88 adults with autism spectrum disorder and 90 adults without autism spectrum disorder were asked to rest for 5 min with their eyes closed and let their mind wander. Directly after, they filled in the Amsterdam Resting-State Questionnaire, which probes what participants were feeling and thinking during the period of rest. We found that adults with autism spectrum disorder tend to think less about others, felt less comfortable, and had more disrupted thoughts during the rest compared to adults without autism spectrum disorder. Interestingly, autism spectrum disorder participants reporting lower levels of comfort during the rest also reported more autism spectrum disorder symptoms, specifically in social behaviors and skills, attention switching, and imagination. We propose to use the eyes-closed rest condition in combination with the Amsterdam Resting-State Questionnaire more widely to shed light on aberrant thoughts and feelings in brain disorders and to study the effect of therapeutic interventions.

Pulmonary circulation biomarkers acquired by cardiovascular magnetic resonance in population after heart transplant

Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This study was supported by the European Regional Development Fund - Project ENOCH. This study was conducted at Masaryk University as part of the project "New Methods in Diagnostic and Stratification of Cardiovascular Diseases" MUNI/A/1393/2019 with the support of the Specific University Research Grant, as provided by the Ministry of Education, Youth and Sports of the Czech Republic in 2019. Introduction Right heart catheterization still remains the golden standard in measuring pulmonary circulation parameters, although its clinical use is limited due to it being an invasive examination. Pulmonary circulation biomarkers acquired by cardiovascular magnetic resonance (CMR) could provide a non-invasive alternative for assuming congestion in patients. Biomarkers such as pulmonary transit time (PTT), pulmonary transit beats (PTB) and pulmonary blood volume index (PBVI) are not new themselves, however, data on cut-off values of these biomarkers and on different populations are limited. To our knowledge, these biomarkers have never been measured in patients after heart transplant (HT) before and PTT from stress perfusion has only been acquired by a single study, which makes the data on this relatively new marker very limited. Purpose The purpose of this study was to calculate PTT stress/rest ratio and provide more evidence about pulmonary circulation biomarkers in HT patients. Methods In this retrospective study, 38 patients after HT who had undergone a CMR examination including contrast methods and stress CMR perfusion were enrolled. PTT values in both rest and stress perfusion were measured as peak-to-peak time in main contrast bolus of dual-bolus stress CMR examination. PTB was calculated by dividing PTT by RR interval obtained from heart rate and PBVI from PTB and right ventricle systolic volume. PTT under stress and rest condition was afterwards compared and PTT ratio was calculated dividing stress values by rest values. Obtained results were further compared to a healthy group as published previously. PTT ratio of HT patients was then compared to measurements conducted on a control group consisting of 10 patients after anthracycline treatment. Results Patients after HT showed biomarker values as follows PBVI 250 ± 59 mL/m2, PTT 6,26 ± 1,05 s, PTT stress 5,66 ± 1,09 s, PTB 7,39 ± 1,31 and PTT ratio 0,91 ± 0,14. These results resemble previously published healthy group values (PBVI 308 ± 92 ml/m2, PTT 6,8 s, PTB 7) and none of the patients enrolled in our study crossed the presented cut-off value of PBVI 492 mL/m2 for hemodynamic congestion. PTT ratio in our control group was 0,77 ± 0,14. In both the populations, PTT values under stress were lower than in rest condition and therefore PTT ratio values were below 1. Conclusions The study provided more evidence about pulmonary circulation biomarkers acquired by CMR in HT patients and presented PTT ratio as a new biomarker. Patients 1 year after HT have comparable values to those of healthy population. PTT stress values were shorter than PTT rest values in both HT group and control group.

A New Soft RCC Device with Pneumatic Regulation

The work described in this paper aims at exploiting the characteristic of a special deformable actuator with rolling membranes to realize a device with defined Remote Center of Compliance (RCC). Starting from theoretical approaches to the definition of the RCC, the authors propose a novel and simple formulation that can be applied to the soft actuator to determine its RCC. The position of the device’s RCC was determined by creating an asymmetry on the geometry of the device along its axis, i.e., by imposing a longitudinal displacement to the piston with respect to the membranes’ rest condition. FEM simulations of the device behavior were carried out and a first formulation describing the placement of the RCC by varying the operating pressure was found. Finally, a comparison of the theoretical model and FEM results is presented, validating the proposed formulation.