Alpha Rhythm

阿尔法节奏
  • 文章类型: Journal Article
    在受控实验室环境中认知需求测量的可靠性是有据可查的;然而,有限的研究直接建立了它们在现实生活和高风险条件下的稳定性,例如在实际高速公路上运行自动化技术。部分自动化车辆已经发展成为一种日常运输方式,和研究驾驶这些先进的车辆需要可靠的工具来评估对驾车者的认知需求,以维持在驾驶过程中的最佳参与。这项研究考察了五种认知需求测量的可靠性,而参与者在真实道路上操作部分自动驾驶车辆的次数有四次。71名参与者(18-64岁)在实际高速公路上开车,心率变异性,脑电图(EEG)α功率,同时测量检测响应任务的行为表现。研究结果表明,脑电图α功率具有出色的重测可靠性,心率和变异性都很好,检测响应任务反应时间和命中率具有中等可靠性。因此,当前的研究解决了对这些措施在评估现实世界自动化研究中的认知需求的可靠性的担忧,因为在不同场合的驾驶员的所有措施中都发现了可接受的重测可靠性。尽管每一项措施的可靠性都很高,观察到测量之间的相互关系较低,当认知需求被估计为多因素结构时,内部一致性更好。这表明他们在现实生活中操作自动化的同时利用了认知需求的不同方面。研究结果强调,心理生理学和行为方法的结合可以可靠地捕获现实世界自动化研究中多方面的认知需求。
    The reliability of cognitive demand measures in controlled laboratory settings is well-documented; however, limited research has directly established their stability under real-life and high-stakes conditions, such as operating automated technology on actual highways. Partially automated vehicles have advanced to become an everyday mode of transportation, and research on driving these advanced vehicles requires reliable tools for evaluating the cognitive demand on motorists to sustain optimal engagement in the driving process. This study examined the reliability of five cognitive demand measures, while participants operated partially automated vehicles on real roads across four occasions. Seventy-one participants (aged 18-64 years) drove on actual highways while their heart rate, heart rate variability, electroencephalogram (EEG) alpha power, and behavioral performance on the Detection Response Task were measured simultaneously. Findings revealed that EEG alpha power had excellent test-retest reliability, heart rate and its variability were good, and Detection Response Task reaction time and hit-rate had moderate reliabilities. Thus, the current study addresses concerns regarding the reliability of these measures in assessing cognitive demand in real-world automation research, as acceptable test-retest reliabilities were found across all measures for drivers across occasions. Despite the high reliability of each measure, low intercorrelations among measures were observed, and internal consistency was better when cognitive demand was estimated as a multi-factorial construct. This suggests that they tap into different aspects of cognitive demand while operating automation in real life. The findings highlight that a combination of psychophysiological and behavioral methods can reliably capture multi-faceted cognitive demand in real-world automation research.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    干电极在可穿戴设备等新兴应用中的潜在用途,灵活的纹身电路,可拉伸显示器需要,成为切实可行的解决方案,容易制造等问题,耐用性强,必须解决低成本材料问题。本研究的目的是提出由聚二甲基硅氧烷(PDMS)和碳纳米管(CNT)复合材料开发的软电极和干电极。与常规和内部NTAmp生物信号仪器相连,用于比较研究,通过肌电图(EMG)评估了所提出的干电极的性能,心电图(ECG),和脑电图(EEG)测量。结果表明,PDMS/CNT电极接收生物信号的能力与商用电极(粘合剂和金杯电极)相当。根据刺激的类型,实现了5-10dB范围的信噪比(SNR)。研究结果表明,所提出的干电极的性能与商用电极相当,提供各种应用的可能性。这些应用可能包括重要医学体征的身体检查,智能设备和机器人的控制,以及通过柔性材料传输信号。
    Potential usage of dry electrodes in emerging applications such as wearable devices, flexible tattoo circuits, and stretchable displays requires that, to become practical solutions, issues such as easy fabrication, strong durability, and low-cost materials must be addressed. The objective of this study was to propose soft and dry electrodes developed from polydimethylsiloxane (PDMS) and carbon nanotube (CNT) composites. Connected with both conventional and in-house NTAmp biosignal instruments for comparative studies, performances of the proposed dry electrodes were evaluated through electromyogram (EMG), electrocardiogram (ECG), and electroencephalogram (EEG) measurements. Results demonstrated that the capability of the PDMS/CNT electrodes to receive biosignals was on par with that of commercial electrodes (adhesive and gold-cup electrodes). Depending on the type of stimuli, a signal-to-noise ratio (SNR) of 5-10 dB range was achieved. The results of the study show that the performance of the proposed dry electrode is comparable to that of commercial electrodes, offering possibilities for diverse applications. These applications may include the physical examination of vital medical signs, the control of intelligent devices and robots, and the transmission of signals through flexible materials.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    我们对脑瘫患者认知功能障碍的神经生物学基础的理解非常有限,特别是在视觉选择性注意的神经认知领域。这项研究利用脑磁图和基于Eriksen箭头的侧翼任务来量化一组患有脑瘫的年轻人和成年人(n=31;年龄范围=9至47岁)和神经典型对照(n=38;年龄范围=11至49岁)的选择性注意力的动力学。将脑磁图数据转换到时频域以识别神经振荡响应,并使用波束形成方法进行成像。行为结果表明,所有参与者都表现出侧翼效应(与一致状态相比,不一致状态的响应时间更长),并且脑瘫患者在任务执行过程中速度较慢且准确性较低。我们计算了干扰图以专注于注意力成分,并在脑瘫组中的右初级视觉皮层中发现了异常的α(8至14Hz)振荡。Alpha和theta(4至7Hz)振荡也在左右脑岛中看到,这些振荡随着所有参与者的年龄而变化。总的来说,脑瘫患者在提供视觉选择性注意力的皮质动力学方面表现出缺陷,但是这些畸变似乎并不受年龄的唯一影响。
    Our understanding of the neurobiology underlying cognitive dysfunction in persons with cerebral palsy is very limited, especially in the neurocognitive domain of visual selective attention. This investigation utilized magnetoencephalography and an Eriksen arrow-based flanker task to quantify the dynamics underlying selective attention in a cohort of youth and adults with cerebral palsy (n = 31; age range = 9 to 47 yr) and neurotypical controls (n = 38; age range = 11 to 49 yr). The magnetoencephalography data were transformed into the time-frequency domain to identify neural oscillatory responses and imaged using a beamforming approach. The behavioral results indicated that all participants exhibited a flanker effect (greater response time for the incongruent compared to congruent condition) and that individuals with cerebral palsy were slower and less accurate during task performance. We computed interference maps to focus on the attentional component and found aberrant alpha (8 to 14 Hz) oscillations in the right primary visual cortices in the group with cerebral palsy. Alpha and theta (4 to 7 Hz) oscillations were also seen in the left and right insula, and these oscillations varied with age across all participants. Overall, persons with cerebral palsy exhibit deficiencies in the cortical dynamics serving visual selective attention, but these aberrations do not appear to be uniquely affected by age.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:暴饮暴食(BE)与一系列与冲动性有关的认知控制缺陷有关,包括较低的反应抑制,偏爱即时满足,和不适应的决策。目的是调查冲动性和BE是否可能与超重或肥胖门诊患者的决策过程和潜在的大脑活动相互作用,这些患者正在开始治疗以实现体重减轻。
    方法:对26名超重或肥胖的门诊患者进行了冲动性评估,BE,和时间折现率。冲动性用Barratt冲动性量表(BIS-11)测量,根据这两组组成:高BIS和低BIS;BE是通过DSM5-Research版本的结构化临床访谈的饮食失调模块进行评估,根据其中两组组成:有(BE组)或无BE(NBE组)。奖励的主观价值的变化是用时间折扣任务(TDt)测量的,参与者必须在较早但较小的与之间进行选择后来,但更大的金钱奖励。这些选择是在两种不同的延迟条件下做出的(“现在”和“现在”)。在TDt期间通过高密度脑电图(hd-EEG)记录脑节律。
    结果:BE患者报告了更多的冲动倾向,并且当两种选择都延迟时,感觉更快的奖励更令人满意(Not-nowcondition,p=0.02)。TDt中的奖励选择伴随着在顶叶区域观察到的一般EEGα带不同步,实验条件和患者组之间没有差异。在Now条件下或在其他EEG波段中未观察到影响。
    结论:对于超重或肥胖的门诊患者,倾向于立即给予奖励的倾向可能构成了坚持治疗计划和实现减肥目标的障碍。因此,鼓励临床医生包括心理因素,比如冲动和功能失调的饮食行为,在设计减肥计划时。通过解决这些心理方面的问题,临床医生可以更好地支持患者克服依从性障碍并实现可持续减肥.
    背景:这项研究得到了心理部伦理委员会的批准,健康,和基耶蒂-佩斯卡拉的G.d'Annunzio大学的领土科学(Prot.2017年3月14日第254号)。
    BACKGROUND: Binge eating (BE) is associated with a range of cognitive control deficits related to impulsivity, including lower response inhibition, preference for immediate gratification, and maladaptive decision-making. The aim was to investigate whether impulsivity and BE may interact with the decision process and underlying brain activity in outpatients with overweight or obesity who are starting a treatment to achieve weight loss.
    METHODS: A sample of 26 treatment-seeking outpatients with overweight or obesity was evaluated for impulsivity, BE, and temporal discounting rates. Impulsivity was measured with the Barratt Impulsiveness Scale (BIS-11), according to which two groups were composed: high BIS and low BIS; BE was assessed with the eating disorders module of the Structured Clinical Interview for DSM5-Research Version, according to which two groups were composed: with (BE group) or without BE (NBE group). Changes in subjective value of rewards were measured with the Temporal Discounting Task (TDt) where participants had to choice between sooner but smaller vs. later but larger monetary rewards. These choices were made in two differently delayed conditions (\"Now\" and \"Not-now\"). Brain rhythms were recorded through high-density electroencephalogram (hd-EEG) during the TDt.
    RESULTS: Patients with BE reported more impulsive tendencies and perceived sooner rewards as more gratifying when both options were delayed (Not-now condition, p = 0.02). The reward choice in the TDt was accompanied by a general EEG alpha band desynchronization in parietal areas observed without differences between experimental conditions and patients groups. No effects were observed within the Now condition or in the other EEG bands.
    CONCLUSIONS: The tendency to favor immediate rewards may constitute an obstacle to adhering to treatment plans and achieving weight loss goals for outpatients with overweight or obesity. Clinicians are therefore encouraged to include psychological factors, such as impulsivity and dysfunctional eating behaviors, when designing weight loss programs. By addressing these psychological aspects, clinicians can better support patients in overcoming barriers to adherence and achieving sustainable weight loss.
    BACKGROUND: This study was approved by the Ethics Committee of the Department of Psychological, Health, and Territorial Sciences of the University G. d\'Annunzio of Chieti-Pescara (Prot. n. 254 of 03/14/2017).
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    参与对话需要对话者协调发送和接收语言信号,以建立基于与一系列情感相互联系的解释和感知的话语。用外语交谈可能会引起焦虑等情绪,从而影响沟通的质量。支持这些互动的神经过程对于理解外语焦虑(FLA)至关重要。脑电图(EEG)研究表明,焦虑通常通过半球额叶α不对称(FAA)表现出来。为了检查FLA背后的神经机制,我们收集了第二语言技能特定焦虑量表(L2AS)的听力和口语部分的自我报告数据,认知,和体域,并在参与第一(L1,中文)和第二(L2,英语)语言的词链转向活动期间记录EEG信号。回归分析显示,L2状况的FAA主要是L2AS口语部分的行为和体细胞域的重要预测因子。讨论了结果,以及对改善L2交互过程中的交流的启示。
    Engaging in dialog requires interlocutors to coordinate sending and receiving linguistic signals to build a discourse based upon interpretations and perceptions interconnected with a range of emotions. Conversing in a foreign language may induce emotions such as anxiety which influence the quality communication. The neural processes underpinning these interactions are crucial to understanding foreign language anxiety (FLA). Electroencephalography (EEG) studies reveal that anxiety is often displayed via hemispheric frontal alpha asymmetry (FAA). To examine the neural mechanisms underlying FLA, we collected self-reported data on the listening and speaking sections of the Second language skill specific anxiety scale (L2AS) over behavioral, cognitive, and somatic domains and recorded EEG signals during participation in word chain turn-taking activities in first (L1, Chinese) and second (L2, English) languages. Regression analysis showed FAA for the L2 condition was a significant predictor primarily of the behavioral and somatic domains on the L2AS speaking section. The results are discussed along with implications for improving communication during L2 interactions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    关于知觉训练的研究很多,然而,大多数人都专注于时间视听感知的精确度,而更少的人专注于视听整合(AVI)的能力提升。为了调查这些问题,连续5天的视听知觉训练,在此期间进行脑电图检查以响应仅听觉(A),训练前后的仅视觉(V)和视听(AV)刺激。结果表明,训练组的知觉敏感性高于对照组,后测中的知觉敏感性高于前测。对于年龄较大的训练组,后测对AV刺激的反应明显快于前测,但对于年轻的训练组,A和V刺激的反应明显更大。脑电图分析发现,后测中的P3AVI振幅[AV-(AV)]高于训练组的预测试,随后通过增加的α(8-12Hz)振荡响应和增强的全球功能连通性(加权相位滞后指数)来反映。此外,老年培训组的这些便利程度高于年轻培训组.这些结果证实,随着视听知觉训练的进展,AVI的年龄相关代偿机制可能会得到加强。为老年人的认知干预提供有效的候选人。
    Numerous studies on perceptual training exist, however, most have focused on the precision of temporal audiovisual perception, while fewer have concentrated on ability promotion for audiovisual integration (AVI). To investigate these issues, continuous 5-day audiovisual perceptual training was applied, during which electroencephalography was performed in response to auditory-only (A), visual-only (V) and audiovisual (AV) stimuli before and after training. The results showed that the perceptual sensitivity was greater for training group than for control group and was greater in the posttest than in the pretest. The response to the AV stimulus was significantly faster in the posttest than in the pretest for the older training group but was significantly greater for A and V stimuli for the younger training group. Electroencephalography analysis found higher P3 AVI amplitudes [AV-(A + V)] in the posttest than in the pretest for training group, which were subsequently reflected by an increased alpha (8-12 Hz) oscillatory response and strengthened global functional connectivity (weighted phase lag index). Furthermore, these facilitations were greater for older training groups than for younger training groups. These results confirm the age-related compensatory mechanism for AVI may be strengthened as audiovisual perceptual training progresses, providing an effective candidate for cognitive intervention in older adults.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    暂无摘要。
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    力量的精确控制在上肢功能康复中具有重要意义。了解力量调节中的神经肌肉反应可以帮助优化康复处方并促进恢复控制的相关训练过程。本研究旨在探讨动态手部力量调节过程中神经肌肉活动的内在特征。通过操纵力变化的不同幅度和速度,设置了四种动态抓地力跟踪模式,13名健康的年轻人参加了实验。脑电图记录在对侧感觉运动皮质区,同时收集第一背侧骨间肌的肌电图。与事件相关的去同步的度量,肌电图稳定性指数,和力的变化,用于表示相应的皮层神经反应,肌肉收缩活动,以及力量调节的水平,分别;并通过转移熵分析进一步研究了感觉运动皮层和第一骨间背侧肌之间的神经肌肉耦合。结果表明,力调节需求的增加将导致力变化增加以及肌肉运动单位输出的稳定性降低。同时,神经反应强度在α和β频段均增加。随着部队调节需求的增加,双向转移熵的强度显示出从β到γ频带的明显偏移,便于动态强度补偿的快速集成,以适应电机任务的变化。
    Precise control of strength is of significant importance in upper limb functional rehabilitation. Understanding the neuro-muscular response in strength regulation can help optimize the rehabilitation prescriptions and facilitate the relative training process for recovery control. This study aimed to investigate the inherent characteristics of neural-muscular activity during dynamic hand strength adjustment. Four dynamic grip force tracking modes were set by manipulating different magnitude and speed of force variations, and thirteen healthy young individuals took participation in the experiment. Electroencephalography were recorded in the contralateral sensorimotor cortex area, as well as the electromyography from the first dorsal interosseous muscle were collected synchronously. The metrics of the Event-related desynchronization, the electromyography stability index, and the force variation, were used to represent the corresponding cortical neural responses, muscle contraction activities, and the level of strength regulation, respectively; and further neuro-muscular coupling between the sensorimotor cortex and the first dorsal interosseous muscle was investigated by transfer entropy analysis. The results indicated a strong relationship that the increase of force regulation demand would result in a force variation increase as well as a stability reduction in muscle motor unit output. Meanwhile, the intensity of neural response increased in both the α and β frequency bands. As the force regulation demand increased, the strength of bidirectional transfer entropy showed a clear shift from β to the γ frequency band, which facilitate rapid integration of dynamic strength compensation to adapt to motor task changes.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    虽然皮层振荡的形状越来越被认为是生理和功能上的信息,它与老化的电机系统的相关性尚未确定。因此,我们检查了静止时记录的α和β带振荡的形状,以及在执行简单和执行/不执行反应时间任务期间,在33名年轻人(23.3±2.9岁,27名女性)和27岁以上(60.0±5.2岁,23名女性)成人。使用最近开发的涉及经验模式分解的管道来表征各个振荡周期的形状,在使用主成分分析分解为波形基序之前。这揭示了受任务和/或年龄影响的四个主要成分。这些描述了形状的特定尺寸,并倾向于在每个任务的反应阶段进行调制。我们的结果表明,尽管振荡形状与任务有关,这种影响的性质随着年龄的增长而改变,可能反映了皮质活动的改变。这些结果证明了这种方法对于理解衰老的神经生理效应的实用性。
    While the shape of cortical oscillations is increasingly recognised to be physiologically and functionally informative, its relevance to the aging motor system has not been established. We therefore examined the shape of alpha and beta band oscillations recorded at rest, as well as during performance of simple and go/no-go reaction time tasks, in 33 young (23.3 ± 2.9 years, 27 females) and 27 older (60.0 ± 5.2 years, 23 females) adults. The shape of individual oscillatory cycles was characterised using a recently developed pipeline involving empirical mode decomposition, before being decomposed into waveform motifs using principal component analysis. This revealed four principal components that were uniquely influenced by task and/or age. These described specific dimensions of shape and tended to be modulated during the reaction phase of each task. Our results suggest that although oscillation shape is task-dependent, the nature of this effect is altered by advancing age, possibly reflecting alterations in cortical activity. These outcomes demonstrate the utility of this approach for understanding the neurophysiological effects of ageing.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    峰值α频率因个体和精神状态而异,但它也形成了一个负梯度,从后部到前部区域,与皮质厚度和连通性的增加有关,反映了时间整合中的皮层层次结构。跟踪头皮脑电图中峰值α频率的空间标准偏差,我们观察到前后梯度动态形成和溶解。高空间标准偏差的时期产生了稳健的负的前后梯度-“梯度状态”-而低空间标准偏差的时期产生了全局收敛的峰值-α频率-“均匀状态”。状态变化的特征是缓慢(0.3Hz-0.5Hz)振荡和随机游走式波动的组合。它们与前部区域的峰值-α频率变化和后部区域驱动的中部区域的峰值-α功率变化相对独立相关(总共占状态变化的50%),这表明两种不同的机制可以调节状态变化:一种直接调节峰值α频率的前机制和一种通过影响同步间接调节它们的后中心机制。状态变化可能反映了一般操作,因为它们的时空特征保持不变,而参与者从事各种任务(呼吸焦点,警惕,警惕工作记忆,心算,和生成性思维)闭着眼睛,或者看了一段无声的自然视频.正在进行的状态变化可以动态地平衡两个全局处理模式。在梯度状态下,有助于更大的时间整合(以及潜在的信息流入)到前部区域,以及另一个在统一状态下促进灵活的全球通信(通过锁相)。重要性陈述Alpha波段振荡(8-12Hz)涉及各种感官,注意,和认知过程。我们的EEG研究表明,α振荡频率的空间模式在形成负的前后梯度之间动态变化(即,“梯度状态”)和全局收敛(即,“统一状态”)。梯度状态可以促进向前部区域的时间积分(以及潜在的信息流入),而统一状态可以通过锁相促进灵活的全球通信。我们的结果进一步表明,梯度状态和均匀状态之间的变化由两种不同的机制控制:直接调节α振荡频率的前机制和通过增加或减少上α波段的全局振荡夹带来间接调节它们的后机制。
    Peak-alpha frequency varies across individuals and mental states, but it also forms a negative gradient from posterior to anterior regions in association with increases in cortical thickness and connectivity, reflecting a cortical hierarchy in temporal integration. Tracking the spatial standard deviation of peak-alpha frequency in scalp EEG, we observed that a posterior-to-anterior gradient dynamically formed and dissolved. Periods of high spatial standard deviation yielded robustly negative posterior-to-anterior gradients-the \"gradient state\"-while periods of low spatial standard deviation yielded globally converged peak-alpha frequency-the \"uniform state.\" The state variations were characterized by a combination of slow (0.3-0.5 Hz) oscillations and random-walk-like fluctuations. They were relatively independently correlated with peak-alpha frequency variations in anterior regions and peak-alpha power variations in central regions driven by posterior regions (together accounting for ∼50% of the state variations), suggesting that two distinct mechanisms modulate the state variations: an anterior mechanism that directly adjusts peak-alpha frequencies and a posterior-central mechanism that indirectly adjusts them by influencing synchronization. The state variations likely reflect general operations as their spatiotemporal characteristics remained unchanged while participants engaged in a variety of tasks (breath focus, vigilance, working memory, mental arithmetic, and generative thinking) with their eyes closed or watched a silent nature video. The ongoing state variations may dynamically balance two global processing modes, one that facilitates greater temporal integration (and potentially also information influx) toward anterior regions in the gradient state and the other that facilitates flexible global communication (via phase locking) in the uniform state.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号