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1.
Front Psychol ; 15: 1371014, 2024.
Article in English | MEDLINE | ID: mdl-38633874

ABSTRACT

This study investigated the impact of transcutaneous electrical acupoint stimulation (TEAS) at Neiguan acupoint (PC6) on the physiological and behavioral responses of participants exposed in virtual height. 40 participants were included in the study and were randomly assigned to either a control group or an intervention group. Participants had an immersive experience with a VR interactive platform that provided somatosensory interaction in height stimulation scenes. Psychological scores, behavioral and cognitive performance, and physiological responses were recorded and analyzed. The results indicated that the intervention group had significantly lower fear scores compared to the control group. Analysis of heart rate variability revealed that the intervention group exhibited improved heart rate variability, indicating enhanced cardiovascular function and emotion regulation. The behavioral and cognitive results demonstrated that the intervention group exhibited higher left eye openness, faster reaction times, and greater movement distance, suggesting enhanced attentional focus, cognitive processing, and reduced avoidance behaviors. These findings suggest that TEAS at PC6 can effectively reduce fear and improve the regulation of physiological and behavioral responses to negative emotional stimuli.

2.
Front Physiol ; 15: 1340061, 2024.
Article in English | MEDLINE | ID: mdl-38440348

ABSTRACT

Backgrounds: The validity of heart rate variability (HRV) has been substantiated in mental workload assessments. However, cognitive tasks often coincide with physical exertion in practical mental work, but their synergic effects on HRV remains insufficiently established. The study aims were to investigate the combined effects of cognitive and physical load on autonomic nerve functions. Methods: Thirty-five healthy male subjects (aged 23.5 ± 3.3 years) were eligible and enrolled in the study. The subjects engaged in n-back cognitive tasks (1-back, 2-back, and 3-back) under three distinct physical conditions, involving isotonic contraction of the left upper limb with loads of 0 kg, 3 kg, and 5 kg. Electrocardiogram signals and cognitive task performance were recorded throughout the tasks, and post-task assessment of subjective experiences were conducted using the NASA-TLX scale. Results: The execution of n-back tasks resulted in enhanced perceptions of task-load feelings and increased reaction times among subjects, accompanied by a decline in the accuracy rate (p < 0.05). These effects were synchronously intensified by the imposition of physical load. Comparative analysis with a no-physical-load scenario revealed significant alterations in the HRV of the subjects during the cognitive task under moderate and high physical conditions. The main features were a decreased power of the high frequency component (p < 0.05) and an increased low frequency component (p < 0.05), signifying an elevation in sympathetic activity. This physiological response manifested similarly at both moderate and high physical levels. In addition, a discernible linear correlation was observed between HRV and task-load feelings, as well as task performance under the influence of physical load (p < 0.05). Conclusion: HRV can serve as a viable indicator for assessing mental workload in the context of physical activities, making it suitable for real-world mental work scenarios.

3.
Ergonomics ; 67(4): 515-525, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37365918

ABSTRACT

To investigate whether high cognitive task load (CTL) for aircraft pilots can be identified by analysing heart-rate variability, electrocardiograms were recorded while cadet pilots (n = 68) performed the plane tracking, anti-gravity pedalling, and reaction tasks during simulated flight missions. Data for standard electrocardiogram parameters were extracted from the R-R-interval series. In the research phase, low frequency power (LF), high frequency power (HF), normalised HF, and LF/HF differed significantly between high and low CTL conditions (p < .05 for all). A principal component analysis identified three components contributing 90.62% of cumulative heart-rate variance. These principal components were incorporated into a composite index. Validation in a separate group of cadet pilots (n = 139) under similar conditions showed that the index value significantly increased with increasing CTL (p < .05). The heart-rate variability index can be used to objectively identify high CTL flight conditions.Practitioner summary: We used principal component analysis of electrocardiogram data to construct a composite index for identifying high cognitive task load in pilots during simulated flight. We validated the index in a separate group of pilots under similar conditions. The index can be used to improve cadet training and flight safety.Abbreviations: ANOVA: a one-way analysis of variance; AP: anti-gravity pedaling task; CTL: cognitive task load; ECG: electrocardiograms; HR: heart rate; HRV: heart-rate variability; HRVI: heart-rate variability index; PT: plane-tracking task; RMSSD: root-mean square of differences between consecutive R-R intervals; RT: reaction task; SDNN: standard deviation of R-R intervals; HF: high frequency power; HFnu: normalized HF; LF: low frequency power; LFnu: normalized LF; PCA: principal component analysis.


Subject(s)
Cognition , Electrocardiography , Humans , Heart Rate/physiology , Principal Component Analysis
4.
Neuro Endocrinol Lett ; 44(8): 491-499, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38131172

ABSTRACT

BACKGROUND: Standard low-resolution electromagnetic tomography (sLORETA) was used to accurately detect EEG changes in mental fatigue of air traffic controllers (ATCo) under a simulated air traffic control (ATC) task. We explored the changes in standard current density, activated cortical intensity, and brain source location. METHODS: The participants were instructed to use the tower flight command simulation training system for three hours of uninterrupted ATC task. The 3-hour EEG signal was divided into four stages: task start, 1st hour, 2nd hour, and task end. Each stage was preprocessed for 3 minutes to explore the EEG changes and then processed by sLORETA in a statistical non-parametric mapping analysis. RESULTS: The current density distribution of δ and α oscillations differed significantly during the four tasks, while θ, ß and γ oscillations did not. Changes in δ oscillations of the brain during mental fatigue were detected mainly in the postcentral gyrus (BA2 and BA3), precentral gyrus (BA4 and BA6), inferior temporal gyrus (BA20), and superior temporal gyrus (BA38). The α oscillations were found mainly decreased in the postcentral gyrus (BA2) and inferior parietal lobule (BA40) when the task was in progress compared with the end of the task. CONCLUSION: The superior temporal gyrus and somatosensory cortex were the main activated cortical regions during the simulated ATC task. The α and δ oscillations showed contrasting activity during simulated ATC task, which might reflect the release of task-relevant brain's areas from inhibition and enhance the neural activity.


Subject(s)
Brain , Electroencephalography , Humans , Electroencephalography/methods , Brain/diagnostic imaging , Tomography/methods , Brain Mapping , Electromagnetic Phenomena , Mental Fatigue , Magnetic Resonance Imaging
5.
Clin Transl Sci ; 16(12): 2591-2603, 2023 12.
Article in English | MEDLINE | ID: mdl-37786330

ABSTRACT

This study aimed to evaluate the bioequivalence between test tablet dacomitinib and reference product Vizimpro® under fasting and fed conditions and assess their pharmacokinetic (PK) and safety profiles for gaining marketing approval of the new generic drug. A single-center, randomized, open-label, single-dose, two-treatment, two-period, crossover bioequivalence study was conducted in healthy Chinese subjects. Eligible healthy subjects randomly received a single 45 mg dose of test or reference formulations with an administration sequence of test tablet (T), reference tablet (R), or (RT), under both fasting and fed conditions, and each single administration was followed by a 21-day washout period. Plasma concentrations and corresponding non-compartmental PK parameters of dacomitinib were determined. The 90% confidence intervals of the geometric mean ratio (GMR) (test/reference) for Cmax , AUC0-t , and AUC0-∞ , respectively, were 97.75%-119.99%, 101.00%-115.09%, and 100.27%-113.90% under fasting conditions and 95.20%-104.94%, 97.24%-102.23%, and 97.27%-101.88% under fed conditions, which were within the limits of 80%-125%. Under fasting and fed conditions, the PK characteristics of the test dacomitinib tablet and reference Vizimpro® were comparable; the two formulations of dacomitinib were demonstrated to be bioequivalent and well-tolerated in healthy Chinese volunteers.


Subject(s)
Fasting , Humans , Therapeutic Equivalency , Cross-Over Studies , Healthy Volunteers , Tablets , China
6.
Front Neurosci ; 16: 910457, 2022.
Article in English | MEDLINE | ID: mdl-36161182

ABSTRACT

A prolonged period of vigilance task will lead to vigilance decrement and a drop in cognitive efficiency. Although transcranial direct current stimulation (tDCS) can be used to improve cognitive performance following vigilance decrement, the findings in this area of study are inconsistent. This study aims to identify the neuroelectrophysiological and behavioral effects of tDCS over the left dorsolateral prefrontal cortex (DLPFC) on executive vigilance under a continuous monotonous condition. We recruited 29 participants who randomly received 30 min active or sham tDCS before the vigilance task (anode electrode at the left DLPFC, cathode electrode at the right supraorbital area). Participants completed four sessions of vigilance task and five sessions of self-report sleepiness, Oddball task, and Go/Nogo task, for a total of about 5 h. EEG was acquired in real-time throughout the experiment. Repeated measures of ANOVA were utilized to analyze the evolution of each metric with task-on-time. The results demonstrated that subjective arousal state, vigilance performance, event-related potentials (ERPs), and EEG power were significantly affected by time on task. Brain stimulation did not significantly affect the evolution of subjective and objective executive vigilance performance, but significantly modulated spontaneous activity in the alpha and beta bands across the entire brain. The continuous enhancement of the prefrontal cortex increased P2 amplitude for the Oddball task, which was associated with the enhancement of the early stage of information processing. P3 amplitude had a temporary enhancement effect, which significantly decreased following a cognitive fatigue. tDCS had a continuous enhancement effect on N2 amplitude for the Go/Nogo task, which was associated with the enhanced inhibition of distracting stimuli. Together, the current data suggest that anodal tDCS over left DLPFC possibly enhances the early stage of relevant information processing and the inhibitory control of distracting stimuli during a continuous and monotonous vigilance task.

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