Name: psychophysically-anchored, robust thresholding in studying pain-related lateralization of oscillatory prestimulus activity
Uploaded: 2017-01-21T14:00:00.000+00:00
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Description: Watch this Scientific Journal Video about Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity at JoVE.com

/德国科学基金会（DFG）:该作品已被跨区域合作研究中心TRR169"适应性，预测和交互Crossmodal学习"的资助。作者感谢斯蒂芬妮盾对稿件的有益的意见。

<html>实验已通过汉堡医学协会（PV4509）的道德委员会。 1.参加者的选择<ol><li>除了标准的选择标准，如健身的疼痛刺激，头部植入物或预先存在的神经系统疾病，确保参与者不是从急性或慢性疼痛的，都没有服用任何止痛药，而且没有已知的药物滥用史。参与者也应该不会在任何药理研究期间实验前4周采取一部分。 </li><li>包括任何性别的参与者，又照顾到只包括使用激素避孕药13，14，以尽量减少对疼痛感觉周期性变化的影响女性参加。 </li><li>管理任何一种刺激之前，确保参加者以书面形式给出的知情同意。 </li></ol>_title"&gt; 2。脑电图设置<ol><li>选择合适的帽子尺寸，并准备脑电图电极设置按照系统的使用说明书。 </li><li>设置采样率和高/低截止以及录音设备的阻抗限制（建议:500赫兹，0.5赫兹高通滤波器，阻抗&lt;20千欧姆）。 </li><li>确保刺激装置和脑电图设备没有电用电池运行脑电图系统耦合的。 </li><li>确保EEG系统和电脑控制电刺激装置之间的联系是无电势。 </li></ol> 3.电刺激设置<ol><li>为了更好地利用脑电图记录的时间分辨率，保持电刺激越短越好。刺激器设置为与1毫秒的持续时间和400伏最大电压的单一，单相刺激脉冲。如果需要更强烈的疼痛程度，或刺激后的脑电记录的确切时间呢ñOT优先，也可以使用其它刺激方案。 </li><li>确保电刺激器被接通但输出至电极被关闭。为DS7A刺激标记为"输出"的开关，以该装置的正确的应该是在向下位置。 </li><li>找到确定所选择的刺激部位的具有里程碑意义的（S）。对于以手刺激，用拇指和食指（展/拇短屈肌）之间的肌肉。请参与者奠定自己的手放在一个平面上与所有数字伸出和并列。通过平分拇指和食指的第一指关节之间的距离确定的刺激部位。 </li><li>清洁通过施加电极制备凝胶在皮肤上。请务必不要使用酒精或消毒液，这可能会留下残渣在皮肤上，可导致过敏或不可靠的刺激。 </li><li>装上刺激电极，并用编织带的地方固定。 </li><li>问个Ë参与者找到手一个舒适的位置，并尽量不要在实验过程中，动的手，如果可能的。对参加者的方便起见，将手下的软组织，以吸收任何湿度，根据表面的透气性。 </li><li>能由"输出"开关切换到向上的位置的激励器的输出。 </li></ol> 4.确定出发点<ol><li>指导有关如何使用鼠标在屏幕上操作的评定量表的参与者。左半部分代表非疼痛的感觉;右半对应于标准疼痛VAS规模，提供一个范围在一个水平行的形式连续感强度的视觉当量。指出该标尺的绝对中心点不能选择的参与者。提供有关锚点15（ 表1）的标准化的指示的参与者。 </li> &lt;LI&gt;给参与者有机会获得舒适与应用强度不同和记录响应刺激的评级过程。使用在此阶段所收集的信息，以得到一个估计为两个强度一贯唤起强烈但非疼痛感觉（低点）和中度疼痛感觉（高点）表示。继续刺激约25 - 30试验或直到满意已达到良好的预期。在此期间，它可能是有利的，以查询关于强度口头反馈和多次呈现刺激强度的主观相似的参与者。 </li><li>尽量挑选强度随机唤起围绕中心规模的反应。为了获得最佳效果，不要简单地增加或线性降低强度，同时也探索痛苦的一面更极端的末端。这一阶段还应该使参加培训的机会，才能适应潜在的陌生stimulat离子与建立一个一致的评价范围内有一定的参考。由于这个原因，最好是从整个范围的可能刺激强度应用强​​度的同时，也重复一些强度。 </li><li>一旦满意，有两个高点和低点开始强度得到的估计，告知参与者，实验的第一部分是即将开始，他（她）应该保持在额定值的练习，同时随机刺激强度呈现。 </li></ol> 5.确定阈值注:QUEST算法需要估算开始之前，必须指定一些参数。这些参数包括心理功能的陡度（测试版，通常3.5），试验在那里的随机答案预期分数（增量，通常为0.01），且其中虽然无刺激被给予肯定响应甚至预期试验的分数（伽马，没有建议）。贝叶斯estimat离子，预期额定范围之内（SD）和可能的反应（粒）的间距必须指定。对于一个VAS，晶粒应设置为比例（通常为1）的分辨率，和SD应设置得足够大以包括两个秤零点和最大可能的强度加上一些安全余量。这里给出的建议和"典型"的值中详细附带PsychToolbox 6,16的QuestCreate源代码说明。对于在阈值疼痛，至多0.01的伽马值应是合理的。估计方法是在参数设定错误方面相对坚固，但是对于只有几个试验中，未能指定明智参数可能增加最终估算的不确定性的设置。如果标准偏差设置得太低，则程序将具有位于由周围次的标准偏差所跨越的区域之外的问题收敛于估计Ë之前猜测的参数。因此，它在一过大的标准偏差的一侧，而宁可是重要的。 <ol><li>创建具有上面给出的参数的两个QUEST会议。启动一个来自高点强度和一个从低点。有关估计过程的实现逻辑的信息可以在补充材料（S1）被发现。 </li><li>随机选择由相应QuestMean函数给出的两个运行中的一个的探针强度。 </li><li>设置电刺激到探针强度。如果需要应用不同的强度比通过该算法建议或建议的强度超出范围，进料所呈现的强度放回QuestUpdate功能在步骤5.5。 </li><li>触发刺激。 </li><li>参与者已额定的刺激后，运行QuestUpdate用于各个估计会话并提交以及参与者的评级的实际刺激强度供给。 </li><li>继续运行评价试验，直到估计稳定或预定的停止标准（&gt; 40试验）已经达到。 </li><li>记录的平均阈值估计之间既估计运行，从高，低起点出发经QuestMean给出。 </li><li>允许参与者休息在此阶段，如果需要的话。 </li></ol> 6.在刺激阈值水平注意:这是可能的，只要它是可以容忍的参与者以调节等级和块计数您的需求。 <ol><li>通知，对于实验的其余部分，多个块随机刺激将是继参与者，它们应该保持评级之前一样。如果需要的话，刷新上规模锚点的指令。 </li><li>启动脑电图记录。 </li><li>将电刺激器在步骤5.7获得的平均阈值的估计，并保持恒定的设定整个日的休息Ë实验。 </li><li>启动等级块（30次试验），观察脑电图记录的数据质量。根据脑电图数据质量，运行4 - 5块评级，让参与者采取短暂的休息中的块之间。 注意:尝试这些休息时间，保持社会互动与参与到最小或标准化的互动尽可能地。 </li><li>完成后，停止脑电图记录，刺激器输出切换到关闭，并取出电极。取下脑电帽后汇报的参与者。 </li></ol>

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The authors declare that they have no competing financial interests.

在这里，我们使用了好理论上成立QUEST方法能够有效地估计无疼痛和疼痛知觉之间的一个强大的心理门槛。在这道门槛。使用常刺激使独立的刺激变化幅度的感性决策的分析。虽然我们在无害和有毒的感觉结构域之间的转变点检测阈值强度，沿疼痛量表其他点（ 例如，50上的100点疼痛量表）也可以与这里提出的估计方法固定。在这些情况下，护理，必须采取以考虑在整个实验过程中习惯或?...

<html>当进行行为实验涉及人类受试者，其能够精确地控制呈现的刺激的强度是重要的。使用相同强度的刺激所有参与者，但是，将在一些设置引入主观感知的偏差。对于一些感知质量，如疼痛，有在恒定刺激水平1，2感知强度高间和个体内的变化。对于假设等于主观知觉的实验，因此，它是必要的，来匹配参与者主观感觉强度。在阈值电平检查时感知，例如疼痛和非疼痛刺激之间，这也是很重要的。心理物理学的研究已经解决了这些类型的问题了几十年，今天有可实现强大的心理锚复杂的，但易于使用的方法。 ntent"&gt;一个刺激的强度映射到一个单独的感觉幅度的简单，经典方法是阶梯方法3。据此，接连刺激的强度的增加或减少，直到有在参与者的响应有关的变化在主观感觉规模所需的阈值或位置重复的次数这一进程号，产生反转点的合理估计。经典的方法，但是，不能利用包含在每个评价试验的所有信息。这会导致不必要的需要大量的试验，以达到收敛。方法如（线性）回归或函数拟合可能会失败，如果刺激强度和感觉大小之间的关系的假设是错误的或不持有所测试的刺激范围。自适应程序不只产生了一定的主观强度稳健点估计，但这样更有效地做。贝斯LY更长实验，这在很大程度上依赖于阈值或感觉幅度准确的估计，这是必要的心理物理学方法是既坚固的同时有效地相对于所需的试验次数。这是在诸如疼痛研究，其中该总暴露于疼痛刺激应保持尽可能低的参与者的好处尤其重要。 虽然传统的楼梯方法仍然被广泛使用， 例如在定量感觉测试，即更好地利用整个试验获取的信息使用更加先进的估计方法正在稳步增加。在这里使用的最大似然估计法QUEST 4，5的情况下，这可能是由于在流行的Matlab的PsychToolbox 6套件一应俱全实施。这个PR的现代化，修订版ocedure优越于在鲁棒性和低数以足够的估计，如果用正确的设置7用来到达，需要试验的经典估计方法。 在QUEST程序背后的基本原理是，以适应Weibull函数传入数据来刺激强度与感觉大小之间的心理转换模型。对于心理Weibull函数的参数是在由实验者给定部分， 例如 ，函数的陡度或偏移由于假阳性率和响应不一致。沿着强度维感兴趣的参数的定位是通过使用贝叶斯最大似然估计的过程近似。由此，一个概率分布假设在目标参数的位置， 即在阈值强度。鉴于这样的分布的明智之前的假设，该算法将测定T他最翔实强度的参与者应该回应。对于当前实施的程序，这是在现有的概率分布8的平均值。对于每个连续试验中，先验概率分布在本质上是乘以在测试刺激级别的参与者的给定响应的可能性，作为其特征在于由Weibull函数。每个响应将用于不断更新的阈值参数的概率分布的估计。重复这一过程，直到满意估算值产生的。该过程是不是一个简单的回归更有效的，因为它使立即使用所收集的响应，以确定下一个要测试的刺激强度。此外，该过程将具体周围的兴趣点， 例如 ，一个阈值或某些感觉强度探测。从回归这样一个有限的范围内仅使用测试数据将导致一种不稳定估计，使得自适应程序设置里只顾风雨相对较低的号码是可行的更为强劲。 这种强大的心理锚固可以用来测量随时间的疼痛敏感性的变化，痛觉过敏/异常性疼痛的研究或在药物干预镇痛作用调节作用，除其他设置。是能够仅仅两个感觉康体之间的门槛锚刺激的强度另一个有趣的前景是检查对面无痛苦的过渡主观感知疼痛的感觉9，10，11。这种情况是非常有趣的，因为如果疼痛阈已经鲁棒估计，疼痛和无疼痛病症可以在脑电图活动对比，例如，在不改变物理刺激强度12。这允许观测通过检查试验评为痛苦和不痛苦的大脑活动的差异不断地刺激条件下，特定的疼痛感知过程的ervation。 我们将演示如何使用现成的实施自适应估计在PsychToolbox以强劲确定的脑电图实验，其中的痛苦和无痛苦的活动之间的对比检查偏侧的影响，取决于刺激部位个人痛阈。由于刺激强度可以在阈值过程后保持不变，这是没有必要考虑与刺激强度脑电活动共变在随后的分析。

<table><tbody><tr><td>EasyCap electrode cap</td><td>EasyCap, Woerthsee-Etterschlag, Germany</td><td>CUCHW-58</td><td></td></tr><tr><td>actiCap active Ag/Cl EEG electrode set</td><td>BrainProducts GmbH, Gliching, Germany</td><td>-</td><td></td></tr><tr><td>SuperVisc EEG eletrode gel</td><td>EasyCap, Woerthsee-Etterschlag, Germany</td><td>V16</td><td></td></tr><tr><td>BrainAmp EEG amplifier</td><td>BrainProducts GmbH, Gliching, Germany</td><td>BrainAmp Standard</td><td></td></tr><tr><td>PsychToolbox-3</td><td>Mario Kleiner / Open Source</td><td>-</td><td>Available at http://psychtoolbox.org/</td></tr><tr><td>Matlab</td><td>MathWorks, Natick, MA</td><td>Matlab R2015b</td><td></td></tr><tr><td>DigiTimer DS7A constant current electrical stimulator</td><td>DigiTimer Ltd., Hertfordshire, United Kingdom</td><td>DS7A</td><td></td></tr></tbody></table>

psychophysically-anchored, robust thresholding in studying pain-related lateralization of oscillatory prestimulus activity

在知觉的研究，客观地评估提供刺激的平等参与者对面或量化由刺激了多个试验诱发个体内的轰动幅度往往是非常重要的。这需要刺激幅度的健壮映射到感知强度和心理估计方法如楼梯程序通常实现。像对QUEST算法更新，更有效的程序拟合心理功能中的数据实时，而在同一时间最大化的数据收集的效率。痛苦和非疼痛感知之间的阈值强度的鲁棒估计然后可用于减少变化在感觉输入在振荡大脑活动的后续分析的影响。通过在由自适应估计程序确定的常数阈强度刺激，在收视率的方差可直接归因于感知过程。振荡活动然后可以"痛"和"无疼痛"直接试验间对比，产生一个密切涉及伤害感受的知觉分类过程的活性。

使用等级量表分成一半用于非疼痛，另一半为疼痛感觉（ 图1a），恒定的刺激可以通过很多试验中施加而跨过刻度中点仍屈服的评分（ 图1b）。这种方式，在感觉输入的改变可以被避免，评级结果能够直接与相关的疼痛固有感知分类处理。 <img alt="图1" src="/files/ftp_upload/55228/55228fig1.jpg" /> 图1:...

Watch this Scientific Journal Video about Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity at JoVE.com

Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity

心理物理学方法如QUEST估计过程可以有效地得到刺激强度在该非疼痛感觉过渡到疼痛感觉的鲁棒估计。通过在阈强度刺激反复，排名反应的变化可以直接在随后的分析归因于感性的分类。

在研究疼痛相关振荡Prestimulus活动偏侧Psychophysically锚，乐百氏阈值

In perceptual studies, it is often important to objectively assess the equality of delivered stimulation across participants or to quantify the ...

psychophysically-anchored-robust-thresholding-studying-pain-related

Universidad San Sebastian

Research

JoVE Journal

Behavior

6.9K 次观看.  University Medical Center Hamburg Eppendorf. 心理物理学方法如QUEST估计过程可以有效地得到刺激强度在该非疼痛感觉过渡到疼痛感觉的鲁棒估计。通过在阈强度刺激反复，排名反应的变化可以直接在随后的分析归因于感性的分类。 

视频: Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity

Infant Auditory Processing and Event-related Brain Oscillations

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral and temporal changes that are characteristic of human language. These abilities lay the foundation for effective language acquisition; allowing infants to hone in on the sounds of their native language. Invasive procedures in animals and scalp-recorded potentials from human adults suggest that simultaneous, rhythmic activity (oscillations) between and within brain regions are fundamental to sensory development; determining the resolution with which incoming stimuli are parsed. At this time, little is known about oscillatory dynamics in human infant development. However, animal neurophysiology and adult EEG data provide the basis for a strong hypothesis that rapid auditory processing in infants is mediated by oscillatory synchrony in discrete frequency bands. In order to investigate this, 128-channel, high-density EEG responses of 4-month old infants to frequency change in tone pairs, presented in two rate conditions (Rapid: 70 msec ISI and Control: 300 msec ISI) were examined. To determine the frequency band and magnitude of activity, auditory evoked response averages were first co-registered with age-appropriate brain templates. Next, the principal components of the response were identified and localized using a two-dipole model of brain activity. Single-trial analysis of oscillatory power showed a robust index of frequency change processing in bursts of Theta band (3 - 8 Hz) activity in both right and left auditory cortices, with left activation more prominent in the Rapid condition. These methods have produced data that are not only some of the first reported evoked oscillations analyses in infants, but are also, importantly, the product of a well-established method of recording and analyzing clean, meticulously collected, infant EEG and ERPs. In this article, we describe our method for infant EEG net application, recording, dynamic brain response analysis, and representative results.

High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain.

婴儿听觉处理和事件相关的脑振荡

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral ...

科研

行为学

Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging (fMRI) for extracting crucial information about the mechanism of the human brain, such methods remain insufficient to provide information about physiological processes reflecting cognitive and emotional functions at the subcortical level. In this respect, modern invasive clinical approaches in humans, such as deep brain stimulation (DBS), offer a tremendous possibility to record subcortical brain activity, namely local field potentials (LFPs) representing coherent activity of neural assemblies from localized basal ganglia or thalamic regions. Notwithstanding the fact that invasive approaches in humans are applied only after medical indication and thus recorded data correspond to altered brain circuits, valuable insight can be gained regarding the presence of intact brain functions in relation to brain oscillatory activity and the pathophysiology of disorders in response to experimental cognitive paradigms. In this direction, a growing number of DBS studies in patients with Parkinson&#39;s disease (PD) target not only motor functions but also higher level processes such as emotions, decision-making, attention, memory and sensory perception. Recent clinical trials also emphasize the role of DBS as an alternative treatment in neuropsychiatric disorders ranging from obsessive compulsive disorder (OCD) to chronic disorders of consciousness (DOC). Consequently, we focus on the use of combined invasive (LFP) and non-invasive (EEG) human brain recordings in assessing the role of cortical-subcortical structures in cognitive and emotional processing trough experimental paradigms (e.g. speech stimuli with emotional connotation or paradigms of cognitive control such as the Flanker task), for patients undergoing DBS treatment.

The present protocol aims at assessing cognitive-emotional functions in the basal ganglia by simultaneous neurophysiological recording of local field potentials and non-invasive brain cortical activity (EEG). The procedure is exemplified by the use of paradigms involving speech stimuli with emotional connotation or the Flanker task involving cognitive control.

在人类联合微创皮层下和非侵入性的表面神经生理学录音认知的评估和情感作用

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging ...

Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery

Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug&#39;s pharmacology and identify potentially suitable therapeutic populations. The need to use a comprehensive battery of pain models is highlighted by studies whereby only a single pain model, thought to relate to the clinical situation, demonstrates lack of efficacy. No single experimental model can mimic the complex nature of clinical pain. The integrated, multi-modal pain task&#160;battery presented here encompasses the electrical stimulation task, pressure stimulation task, cold pressor task, the UVB inflammatory model which includes a thermal task and a paradigm for inhibitory conditioned pain modulation. These human pain models have been tested for predicative validity and reliability both in their own right and in combination, and can be used repeatedly, quickly, in short succession, with minimum burden for the subject and with a modest quantity of equipment. This allows a drug to be fully characterized and profiled for analgesic effect which is especially useful for drugs with a novel or untested mechanism of action.

Human pain models are valuable tools used to assess the analgesic potential of novel compounds and predict their clinical efficacy, especially when used in an integrated manner. Although implementation of these models is complex, with proper execution, the pain models described in this protocol can provide predictive and reliable results.

确定疼痛的检测和容忍阈值使用集成的，多模式疼痛任务电池

Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug&#39;s pharmacology and identify ...

Monitoring Acupuncture Effects on Human Brain by fMRI

Functional MRI is used to study the effects of acupuncture on the BOLD response and the functional connectivity of the human brain.  Results demonstrate that acupuncture mobilizes a limbic-paralimbic-neocortical network and its anti-correlated sensorimotor/paralimbic network at multiple levels of the brain and that the hemodynamic response is influenced by the psychophysical response.  Physiological monitoring may be performed to explore the peripheral response of the autonomic nerve function. This video describes the studies performed at LI4 (hegu), ST36 (zusanli) and LV3 (taichong), classical acupoints that are commonly used for modulatory and pain-reducing actions. Some issues that require attention in the applications of fMRI to acupuncture investigation are noted.

FMRI and physiological monitoring is used to study the effects of Acupuncture on the central and peripheral nervous systems. Acupuncture mobilizes a limbic-paralimbic-neocortical network, with great overlap with the default mode network, to modulate neurological activity, possibly related to its autonomic effect in the peripheral nervous system.

通过功能磁共振成像监测针灸对人脑的影响

Functional MRI is used to study the effects of acupuncture on the BOLD response and the functional connectivity of the human brain.  Results demonstrate ...

生物学

Simultaneous Recordings of Cortical Local Field Potentials and Electrocorticograms in Response to Nociceptive Laser Stimuli from Freely Moving Rats

Electrocortical responses, elicited by laser heat pulses that selectively activate nociceptive free nerve endings, are widely used in many animal and human studies to investigate the cortical processing of nociceptive information. These laser-evoked brain potentials (LEPs) consist of several transient responses that are time-locked to the onset of laser stimuli. However, the functional properties of the LEP responses are still largely unknown, due to the lack of a sampling technique that can simultaneously record neural activities at the surface of the cortex (i.e., electrocorticogram [ECoG] and scalp electroencephalogram [scalp EEG]) and inside the brain (i.e., local field potential [LFP]). To address this issue, we present here an animal protocol using freely moving rats. This protocol is composed of three main procedures: (1) animal preparation and surgical procedures, (2) a simultaneous recording of ECoG and LFP in response to nociceptive laser stimuli, and (3) data analysis and feature extraction. Specifically, with the help of a 3D-printed protective shell, both ECoG and LFP electrodes implanted on the rat&#39;s skull were securely held together. During data collection, laser pulses were delivered on the rat&#39;s forepaws through gaps in the bottom of the chamber when the animal was in spontaneous stillness. Ongoing white noise was played to avoid the activation of the auditory system by the laser-generated ultrasounds. As a consequence, only nociceptive responses were selectively recorded. Using the standard analytical procedures (e.g., band-pass filtering, epoch extraction, and baseline correction) to extract stimulus-related brain responses, we obtained results showing that LEPs with a high signal-to-noise ratio were simultaneously recorded from ECoG and LFP electrodes. This methodology makes the simultaneous recording of ECoG and LFP activities possible, which provides a bridge of electrocortical signals at the mesoscopic and macroscopic levels, thereby facilitating the investigation of nociceptive information processing in the brain.

We developed a technique that simultaneously records both electrocorticography and local field potentials in response to nociceptive laser stimuli from freely moving rats. This technique helps establish a direct relationship of electrocortical signals at the mesoscopic and macroscopic levels, which facilitates the investigation of nociceptive information processing in the brain.

在自由运动大鼠的反应中, 皮质局部电位和电皮质图谱的同时记录

Electrocortical responses, elicited by laser heat pulses that selectively activate nociceptive free nerve endings, are widely used in many animal and ...

Multi-Modal Signals for Analyzing Pain Responses to Thermal and Electrical Stimuli

The assessment of pain relies mostly on methods that require a person to communicate. However, for people with cognitive and verbal impairments, existing methods are not sufficient as they lack reliability and validity. To approach this problem, recent research focuses on an objective pain assessment facilitated by parameters of responses derived from physiology, and video and audio signals. To develop reliable automated pain recognition systems, efforts have been made in creating multimodal databases in order to analyze pain and detect valid pain patterns. While the results are promising, they only focus on discriminating pain or pain intensities versus no pain. In order to advance this, research should also consider the quality and duration of pain as they provide additional valuable information for more advanced pain management. To complement existing databases and the analysis of pain regarding quality and length, this paper proposes a psychophysiological experiment to elicit, measure, and collect valid pain reactions. Participants are subjected to painful stimuli that differ in intensity (low, medium, and high), duration (5 s / 1 min), and modality (heat / electric pain) while audio, video (e.g., facial expressions, body gestures, facial skin temperature), and physiological signals (e.g., electrocardiogram [ECG], skin conductance level [SCL], facial electromyography [EMG], and EMG of M. trapezius) are being recorded. The study consists of a calibration phase to determine a subject&#8217;s individual pain range (from low to intolerable pain) and a stimulation phase in which pain stimuli, depending on the calibrated range, are applied. The obtained data may allow refining, improving, and evaluating automated recognition systems in terms of an objective pain assessment. For further development of such systems and to investigate pain reactions in more detail, additional pain modalities such as pressure, chemical, or cold pain should be included in future studies. Recorded data of this study will be released as the &#8220;X-ITE Pain Database&#8221;.

This article focuses on the experimental elicitation of pain through heat (thermal) and electrical stimulation while recording physiological, visual, and paralinguistic responses. It aims at collecting valid multimodal data for analyzing pain based on its intensity, quality, and duration.&#160;

分析疼痛对热和电刺激反应的多模态信号

The assessment of pain relies mostly on methods that require a person to communicate. However, for people with cognitive and verbal impairments, existing ...

Dynamic Quantitative Sensory Testing to Characterize Central Pain Processing

Central facilitation and modulation of incoming nociceptive signals play an important role in the perception of pain. Disruption in central pain processing is present in many chronic pain conditions and can influence responses to specific therapies. Thus, the ability to precisely describe the state of central pain processing has profound clinical significance in both prognosis and prediction. Because it is not practical to record neuronal firings directly in the human spinal cord, surrogate behavior tests become an important tool to assess the state of central pain processing. Dynamic QST is one such test, and can probe both the ascending facilitation and descending modulation of incoming nociceptive signals via TS and CPM, respectively. Due to the large between-individual variability in the sensitivity to noxious signals, standardized TS and CPM tests may not yield any meaningful data in up to 50% of the population due to floor or ceiling effects. We present methodologies to individualize TS and CPM so we can capture these measures in a broader range of individuals than previously possible. We have used these methods successfully in several studies at the lab, and data from one ongoing study will be presented to demonstrate feasibility and potential applications of the methods.

By assessing pain in response to repetitive or different types of standardized stimuli, dynamic quantitative sensory testing (QST) can reveal changes in the central processing of pain. We present methods to optimize and individualize two dynamic QST measures: temporal summation (TS) and conditioned pain modulation (CPM).

动态定量感觉测试表征中央疼痛处理

Central facilitation and modulation of incoming nociceptive signals play an important role in the perception of pain. Disruption in central pain ...

神经科学

Electrophysiological Measurement of Noxious-evoked Brain Activity in Neonates Using a Flat-tip Probe Coupled to Electroencephalography

Pain is an unpleasant sensory and emotional experience. In non-verbal patients, it is very difficult to measure pain, even with pain assessment tools. Those tools are subjective or determine secondary physiological indicators which also have certain limitations particularly when exploring the effectiveness of analgesia. As cortical processing is essential for pain perception, brain activity measures may provide a useful approach to assess pain in infants. Here we present a method to assess nociception with electrophysiological brain activity recordings optimized for the use in newborn infants. To produce highly standardized and reproducible noxious stimuli we applied mechanical stimulation with a flat-tip probe, e.g., PinPrick, which is not skin-breaking and does not cause behavioral distress. The noxious-evoked potential allows the objective measurement of nociception in non-verbal patients. This method can be used in newborn infants as early as 34 weeks of gestational age. Moreover, it could be applied in different situations such as measuring the efficacy of analgesic or anesthetic drugs.

Measuring pain in non-verbal patients is a challenge. In this study we combine EEG recording with stimulation using a flat-tip probe to detect noxious-evoked brain activity in an objective manner.

应用平板探针结合脑电图对新生儿有害诱发脑活动的电生理测量

Pain is an unpleasant sensory and emotional experience. In non-verbal patients, it is very difficult to measure pain, even with pain assessment tools. ...

医学

Detecting Pre-Stimulus Source-Level Effects on Object Perception with Magnetoencephalography

Pre-stimulus oscillatory brain activity influences upcoming perception. The characteristics of this pre-stimulus activity can predict whether a near-threshold stimulus will be perceived or not perceived, but can they also predict which one of two competing stimuli with different perceptual contents is perceived? Ambiguous visual stimuli, which can be seen in one of two possible ways at a time, are ideally suited to investigate this question. Magnetoencephalography (MEG) is a neurophysiological measurement technique that records magnetic signals emitted as a result of brain activity. The millisecond temporal resolution of MEG allows for a characterization of oscillatory brain states from as little as 1 second of recorded data. Presenting an empty screen around 1 second prior to the ambiguous stimulus onset therefore provides a time window in which one can investigate whether pre-stimulus oscillatory activity biases the content of upcoming perception, as indicated by participants&#39;&#160;reports. The spatial resolution of MEG is not excellent, but sufficient to localise sources of brain activity at the centimetre scale. Source reconstruction of MEG activity then allows for testing hypotheses about the oscillatory activity of specific regions of interest, as well as the time- and frequency-resolved connectivity between regions of interest. The described protocol enables a better understanding of the influence of spontaneous, ongoing brain activity on visual perception.

This article describes how to set up an experiment that allows detecting pre-stimulus source-level influences on object perception using magnetoencephalography (MEG). It covers stimulus material, experimental design, MEG recording, and data analysis.

利用磁脑学检测刺激前源级对物体感知的影响

Pre-stimulus oscillatory brain activity influences upcoming perception. The characteristics of this pre-stimulus activity can predict whether a ...

Modulation of the Neurophysiological Response to Fearful and Stressful Stimuli Through Repetitive Religious Chanting

In neuropsychological experiments, the late positive potential (LPP) is an event-related potential (ERP) component that reflects the level of one's emotional arousal. This study investigates whether repetitive religious chanting modulates the emotional response to fear- and stress-provoking stimuli, thus leading to a less responsive LPP. Twenty-one participants with at least one year of experience in the repetitive religious chanting of "Amitabha Buddha" were recruited. A 128-channel electroencephalography (EEG) system was used to collect EEG data. The participants were instructed to view negative or neutral pictures selected from the International Affective Picture System (IAPS) under three conditions: repetitive religious chanting, repetitive nonreligious chanting, and no chanting. The results demonstrated that viewing the negative fear- and stress-provoking pictures induced larger LPPs in the participants than viewing neutral pictures under the no-chanting and nonreligious chanting conditions. However, this increased LPP largely disappeared under repetitive religious chanting conditions. The findings indicate that repetitive religious chanting may effectively alleviate the neurophysiological response to fearful or stressful situations for practitioners.

The present event-related potential (ERP) study provides a unique protocol for investigating how religious chanting can modulate negative emotions. The results demonstrate that the late positive potential (LPP) is a robust neurophysiological response to negative emotional stimuli and can be effectively modulated by repetitive religious chanting.

通过重复的宗教吟唱调节对恐惧和压力刺激的神经生理反应

In neuropsychological experiments, the late positive potential (LPP) is an event-related potential (ERP) component that reflects the level of one's ...