我们感谢Rustichini阿尔的设计富有成果的讨论和意见。 IL和PWG由NIA授予R01-AG033406资助。

1。准备实验<ol><li>第一步是设计代表将呈现在屏幕上在扫描仪中的风险和模糊的选择的视觉刺激。我们使用的图像，如在图1来表示袋充满了筹码，我们称之为"彩票袋"。从图形上看，这些图像可以被认为是成堆的筹码之前，它们被放置在一个袋子里。更重要的是，这些图片代表真正的容器，在我们的例子信封，充满了100红色和蓝色的筹码，这个问题将在实验开始前。这将确保受试者都明白，他们将面临认为，计算机显示屏准确地介绍这些彩票的彩票。对于风险的彩票中奖概率，在一个给定的包络线，比红色蓝筹股恰恰是表示同时使用数字和图形的刺激（ 图1A）。对于暧昧彩票的资料n关于概率丢失（ 图1B），例如，可能比红到蓝的芯片是有界的，但是没有被指定，渲染部分暧昧的中奖概率。 </li><li>对风险彩票各图像的红色和蓝色的区域是在信封中的红色和蓝色的芯片的数量成正比。我们建议使用最低的3个结果的概率（ 图1A）。使用的确切概率可以根据不同的具体要求的实验，但实验人员应持谨慎态度非常高和非常低的概率。它是已知的人类受试者通常误传概率低于10％或高于90％5。除非打算研究这个系统的失实陈述，应避免这些极端。 </li><li>为了传达歧义的计算机显示器中的堆栈的芯片的中央部分带有灰色的封堵器的（ 图1B）遮蔽。在灰色地带的num误码率的每种颜色的芯片将是未知的，并且因此概率绘制一个红色或蓝色的芯片将不能精确地知道。例如，在图1B中的中间包封堵器覆盖的袋子的50％，从而红筹股的数目可以是25（如后面的封堵器的所有的芯片是蓝色的）和75之间的任意位置（如果所有的芯片背后封堵器是红色的）。当然，蓝色芯片的数目也可以是这两个值之间的任何地方。 </li><li>提高封堵器的大小，增加了模糊水平（可能的概率绘制一个红色或蓝色的芯片）。我们建议使用至少有3个级别的闭塞，覆盖50〜25袋或75％（ 图1B）。 </li><li>当受试者在电脑上执行任务，我们提出了一系列可能的结果量的每一个中奖概率/歧义。我们建议使用5薪酬水平4，涵盖了广泛的款项，例如:5，9.5，18，34和65 DOLLARS。我们目前的结果显示，胜负彩金额，并显示"0"的其他颜色。例如，在图2中绘制一个红色的芯片会导致赢取$ 18，而绘制蓝筹股将导致一个零的结果。 </li><li>更重要的是，每个受试者会选择两个彩票。为简单起见，我们保持一个恒定的整个实验过程中的选项（在这个例子中有50％的机会赢得5美元），唯一不同的另一种选择。这有两个好处。首先，恒定的选项并没有出现在屏幕上，简化的视觉显示（虽然现在提醒每一个，然后可能会有所帮助）。第二，永远不会改变，因为一个选项，基于回归分析的fMRI信号，可以有效地忽略此参数。请注意，为了有一个"共同货币"的主观价值的参考选项是相同的，这两种类型的试验的风险和含糊不清的彩票。 </li><li>每一个组合重刑的可能性或歧义的水平和数量提出了一个总的至少4倍，且优选，以确保有足够的统计权力的行为和功能磁共振成像分析。一半的重复红色应与一个非零的结果相关联，并在另一半蓝色，避免色彩偏差，以确保在模糊的对称性。 </li><li>我们选择使用一个缓慢的事件相关设计（ 图3），其中的血流动力学反应不同的试验是在时间上相隔。在这样的设计中，每个彩票刺激，简单地说，在我们的情况下为2秒的延迟时间（在我们的例子中，6秒），允许时间的决定相关的神经活动，建立。响应应在一个短暂的时间窗口（1-2秒）。使用的图像，如在图3中所示的一个，作为一个简短的反馈，以使拍摄对象知道已经记录他们的反应。长的休息时间（10秒或铁道部分离试验。E），以便回到基线的血流动力学反应。可以使用更短的休息时间，合适的抖动。高达30次的块组的试验，但千万不要让块需要更长的时间约10分钟。这使得在扫描仪的休息时间，最大限度地提高性能和最大限度地减少受疲劳。为了允许每个概率/模糊性和量的组合中的至少4个重复试验的总数将是至少120， 即 4个街区。 </li><li>准备物理袋（在我们的例子中信封），所以他们在执行任务之前，可以显示他们的主题。它们将被用于以后播放随机选择的试验（s）为还清。准备在实验中使用的图像的每个彩票的袋。填写每包共100扑克/宾果红色和蓝色的芯片，绘制每种颜色的芯片，在显示屏上显示的包的概率相对应的比例。暧昧袋使用一个随机数生成器决定上红色和蓝色芯片的实际数字，对应于每个歧义水平。准备参照袋50个红色和50个蓝色的芯片。准备物理袋，并显示他们的主题是特别重要的受试者招募心理学系。这些科目可能怀疑某种欺骗手段，他们怀疑欺骗他们的反应将是无法解释的。 </li></ol> 2。准备主题<ol><li>每个主题必须填写一份同意书和筛选问卷。筛选形式验证的主题没有任何金属在他们的身上，他们不怀孕或幽闭恐惧症，他们可以安全地扫描。的主题也必须从他们身上所有的金属，在扫描仪的环境，以确保安全。这是至关重要的。 </li><li>为主题的实验有详细的说明。问几个简单的问题，以确保他们了解如何概率伊蒂埃斯及金额在每幅图像传送，并确保他们了解自己的任务。确保不向外界透露任何信息，可能会影响他们的选择。例如，不要帧的选择问题，他们面临的这样一种方式，对特定的风险态度偏差的主题 。他们在实验中每幅图像是指一个单一的特定的物理包，你不能和不会篡改的物理包和压力。还解释说，一半的试验将是胜负彩蓝色，并在半红。说明支付机制，使被摄对象的理解，他们将支付他们的选择。鼓励科目要求任何他们不明白的问题。这是一个关键时期，正在建立有关实验的受试者的信仰。至关重要的是，主题是信心的实验不涉及任何类型的欺骗的行为和神经的结果将是无法解释的。 </li><li>密封袋，并有主题，在封口处签上自己的名字。解释说，这将使他们验证的实验，在实验过程中并没有改变内容的包包。这有助于安抚的主题，他们是在玩一个完全公平的游戏。也解释后的彩票的玩法，在实验结束后，他们将被允许看，成袋的内容，以确保它们符合规定的可能性或歧义水平。 </li></ol> 3。扫描<ol><li>我们使用的3T MRI扫描仪，头部线圈（4通道或以上），以获得全脑血氧水平依赖（BOLD）信号。 </li><li>使用的是2键的响应框，记录受试者的选择。 </li><li>解剖扫描:，我们使用T1加权MPRAGE的序列，以获得清晰的高清晰度（1x1x1毫米），可用于三维重建的主体的大脑图像。任何高分辩率的序列可以用于此purpose。 </li><li>功能的扫描:使用T2 *加权EPI序列，2秒，3×3×3毫米体素的TR。确保定位片，它们包括你的大脑区域是最感兴趣的，通常是前额叶皮质，顶叶皮质和基底神经节。为特定的扫描仪扫描参数进行优化，我们使用:TE 30毫秒，翻转角75°，36 3毫米片，用无片间的差距，AC-PC线平行，在平面分辨率的3x3 mm，FOV 192毫米。其他的研究表明，在30℃的AC-PC线定位片，可减少信号丢失的眶额皮层6。 </li></ol> 4。付款程序<ol><li>后从扫描仪中取出的主题，检索数据从电脑上记录拍摄对象的反应行为。 </li><li>随机选择一个或几个试验付款。最好是让拍摄对象的选择，例如，绘制一个带编号的扑克筹码从一个不透明的袋子，包含所有的试验编号的芯片。这将确保选择的主题的确是随机的。 </li><li>对于每个选定的试验表明所提出的选项，选择该试验的主题。问他们画一个芯片上选择该试验从包里，并支付他们根据绘制的颜色和量的试验。 </li></ol>例如，如果在选定的试验提出的彩票描绘在图2（一个模糊的彩票，提供18美元如果一家红筹被画）和在主题选择这种彩票，而不是在参考彩票，那么这个问题应该画一个芯片出彩票图像对应的物理袋。如果红筹画的主题将获得$ 18，如果蓝筹股绘制，他们将什么也得不到。 5。分析行为数据<ol><li>利用最大似然，我们的后勤适合每个科目的选择数据函数的形式: </li></ol><img alt="式（1）" src="/files/ftp_upload/3724/3724eq1.jpg" /> Pv是该主体的概率选择的可变的彩票，SV F和SV V的固定和可变的选项的主观值分别和γ是物流函数的斜率，这是特定的被摄体的参数。另一种方法是使用一个概率分布。 <ol start="2"><li>每个选项的主观价值模型为每个主题，你可以使用一些模型，考虑到帐户的金额，概率和模糊性的选项和个人主体对风险和模糊的态度。我们选择使用电源功能5，其中包括一个线性效果的模糊性上感知的概率7: </li></ol><img alt="公式2" src="/files/ftp_upload/3724/3724eq2.jpg" /> 其中，p为目标的概率能力（暧昧的彩票类定义0.5），A是模糊水平（分数的总概率是未知的，危险的彩票为0），V是的金额，和α和βare的特定主题的风险和模糊性姿态参数。几种可供选择的方法之一是有歧义指数的影响: <img alt="式（3）" src="/files/ftp_upload/3724/3724eq3.jpg" /> 因此，选择适合的选择功能，提供了对风险的态度（α）和模糊性的态度（β）为每个主题的估计。 6。分析的神经数据<ol><li>执行标准预处理的数据，包括:1）切片的扫描时间校正考虑到不同的片扫描时间的细微差异; 2）区域内和跨经营主体运动的运动校正; 3）拆除低频率，通常ŕ兴高采烈的生理噪声和扫描仪漂移。 </li><li>注册的功能数据，每个受他们的解剖数据。 </li><li>在单一主体的活动，每个体素模型作为一个持续的反应，在整个审判（在我们的例子10秒），卷积，一个标准的血流动力学响应函数9的分析。使用广义线性模型的以下预测: </li></ol><ul><li>主观价值的预测（SV），高风险试验，和一个暧昧试验的。使用式（2）和来自行为拟合计算SV的每个彩票的单独被摄体的特定参数。由于参考彩票是一样的，对于所有的试验中，我们可以使用单独的SV的变量彩票在每一次试验。对于风险SV预测的插入SV每一个危险的试验，每个易混淆的试验，暧昧的预测，反之亦然。 </li><li>两个虚拟的预测，一个危险的试验，一个暧昧试验，上限未来的总激活，如视觉和运动激活。 </li></ul><ol start="4"><li>看为在其中的系数的SV下的风险和/或下歧义是显着的体素。显着性的测试，应采取考虑到执行的多重比较。我们所用的方法是限制最小的簇大小6个连续体素10。另外，其它的方法，如假发现率（FDR），11，可用于纠正多个修正。 </li></ol> 7。代表性的成果行为 图4给出了三个有代表性的对象的行为结果。每个面板提供选择的数据和模型的拟合结果为一个主题下风险（左）或含糊不清（右）。该图描绘的主题选择的试验中，量的函数的变量彩票的比例，分别为每个级别的概率能力或歧义。从图中可以看出，主体可能会在他们对风险和模糊的态度有很大的差异。 要检查善良的契合，R 2，理想情况下应该超过0.5，也视觉检查的曲线。虽然我们所有的三个例子有合法的行为，使合理的配合，注意，2个月几乎没有选择的变量选择的概率最低（0.13）的风险状况。这表明，扩大的范围内的量和/或使用更高的概率可能会提供更好的结果，因为这将确保受试者选择试验中的至少一些上的可变的选项。另一种选择是每个科目测试就广泛的款项，并选择那些金额，以确保一个相当数量的参考变量为每个选项选择。 功能磁共振成像 图5给出了成像效果的一名代表的主题。突出显示的体素的模糊预测下的主观价值（顶部）或风险（底部）的系数是显着不同，从0。在这个典型的问题，显着的相关性，发现在两种情况下内侧前额叶皮层（MPFC）和纹状体。这些区域是最一致的跨学科，但显着的相关性也可以预期在内侧和外侧的顶叶皮质，以及杏仁核地区。在这种类型的任务活动通常是脆弱的和嘈杂的，你应该期望与许多学科中的一个子领域具有显著的相关性，跨学科的高变异性。 <img alt="图1" src="/files/ftp_upload/3724/3724fig1.jpg" /> 图1。风险和含糊不清的刺激冒险的刺激。A）在每个图像在屏幕上的红色和蓝色区域是在信封的红色和蓝色的芯片的数量成正比。三种结果的概率瓦特ERE用在这里:0.13，0.25和0.38。 B）在不明刺激的图像的中央部分被遮住带有灰色的封堵器。的灰色区域中的每种颜色的数目的芯片是未知的，因而是不知道精确的概率的某一种颜色绘制一个芯片。三个层次的歧义用在这里，25日，50％或75％被遮挡的图像。 <img alt="图2" src="/files/ftp_upload/3724/3724fig2.jpg" /> 图2。一个彩票的例子。这是一个暧昧的彩票，在50％的歧义。至少有25个在信封上的芯片是红色的，至少有25个是蓝色的。如果红筹画的主题将获得18元，同时他们也将赢得什么，如果蓝筹股绘制。 <img alt="图3" src="/files/ftp_upload/3724/3724fig3.jpg" /> 图3。试验结构。彩票是简要介绍，随后的延迟时间。的响应提示，然后提示的主题，以指示在屏幕上，参考彩票彩票（在这种情况下，50％的机会赢得5美元）的红外之间做出选择。试验交错的长的休息时间。 <img alt="图4" src="/files/ftp_upload/3724/3724fig4.jpg" /> 图4。单一主体选择行为的例子。的图表呈现的试验中，每个主题选择参考的变量选择权的比例，所提供的量的函数，在危险的（左）和的暧昧（右）试验。不同的曲线是不同的风险或含糊不清的水平。 α，风险态度参数β，模棱两可的态度参数;ŕ2，麦克法登的伪R平方，一个衡量适合的行为模式的善良，相等于该部分的差异，是解释的模型;Ň，数试验中，反应共（满分180）。 <img alt="图5" src="/files/ftp_upload/3724/3724fig5.jpg" /> &lt;BR /&gt; 图5。单科激活地图的例子。激活地图在高分辨率的解剖图像。突出显示的区域是这些风险（顶部）或模棱两可（底部）与主观价值下，其活性显着相关。在大多数科目内侧前额叶皮层（MPFC）和纹状体的主观价值下风险和歧义。校正P值是基于最低的簇大小为6个功能体素。 <a href="http://jove.unicartagenaproxy.elogim.com/files/ftp_upload/3724/3724fig5large.jpg" target="_blank">点击此处查看大图</a> 。

<ol>
	<li>Glimcher, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+risk:+a+guide+for+the+perplexed.">Understanding risk: a guide for the perplexed.</a> Cogn. Affect Behav. Neurosci. 8, 348-354 (2008).</li><li>Camerer, C., Weber, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+Developments+in+Modeling+Preferences+-+Uncertainty+and+Ambiguity.">Recent Developments in Modeling Preferences - Uncertainty and Ambiguity.</a> Journal of Risk and Uncertainty. 5, 325-370 (1992).</li><li>Holt, C. A., Laury, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+aversion+and+incentive+effects.">Risk aversion and incentive effects.</a> Am. Econ. Rev. 92, 1644-1655 (2002).</li><li>Levy, I., Snell, J., Nelson, A. J., Rustichini, A., Glimcher, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+representation+of+subjective+value+under+risk+and+ambiguity.">Neural representation of subjective value under risk and ambiguity.</a> J. Neurophysiol. 103, 1036-1047 (2010).</li><li>Kahneman, D., Tversky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospect+Theory+-+Analysis+of+Decision+under+Risk.">Prospect Theory - Analysis of Decision under Risk.</a> Econometrica. 47, 263-291 (1979).</li><li>Deichmann, R., Gottfried, J. A., Hutton, C., Turner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+EPI+for+fMRI+studies+of+the+orbitofrontal+cortex.">Optimized EPI for fMRI studies of the orbitofrontal cortex.</a> Neuroimage. 19, 430-441 (2003).</li><li>Gilboa, I., Schmeidler, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maxmin+Expected+Utility+with+Non-Unique+Prior.">Maxmin Expected Utility with Non-Unique Prior.</a> J. Math Econ. 18, 141-153 (1989).</li><li>Hsu, M., Bhatt, M., Adolphs, R., Tranel, D., Camerer, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+systems+responding+to+degrees+of+uncertainty+in+human+decision-making.">Neural systems responding to degrees of uncertainty in human decision-making.</a> Science. 310, 1680-1683 (2005).</li><li>Boynton, G. A., Engel, S. A., Glover, G., Heeger, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> J Neurosci. 16, 4207-4221 (1996).</li><li>Forman, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+Assessment+of+Significant+Activation+in+Functional+Magnetic-Resonance-Imaging+(Fmri)+-+Use+of+a+Cluster-Size+Threshold.">Improved Assessment of Significant Activation in Functional Magnetic-Resonance-Imaging (Fmri) - Use of a Cluster-Size Threshold.</a> Magnetic Resonance in Medicine. 33, 636-647 (1995).</li><li>Genovese, C. R., Lazar, N. A., Nichols, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thresholding+of+statistical+maps+in+functional+neuroimaging+using+the+false+discovery+rate.">Thresholding of statistical maps in functional neuroimaging using the false discovery rate.</a> NeuroImage. 15, 870-878 (2002).</li><li>Huettel, S. A., Stowe, C. J., Gordon, E. M., Warner, B. T., Platt, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+signatures+of+economic+preferences+for+risk+and+ambiguity.">Neural signatures of economic preferences for risk and ambiguity.</a> Neuron. 49, 765-775 (2006).</li><li>Smith, V. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Papers in experimental economics. , (1991).</li></ol>

没有利益冲突的声明。

我们使用了从实验经济学的方法来描述主体的行为，并估计个人对风险和模糊的态度。然后，我们用这些估计神经的数据进行分析。 8,12已使用过的其他方法检查功能磁共振成像活动，而主题下做出选择风险和模糊性。我们的做法，但是，结合了几个重要的特点。首先，它采用了参数化设计，在不同的参数（数量，概率和模糊性水平）系统的变化。这使我们能够量化?...

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measuring the subjective value of risky and ambiguous options using experimental economics and functional mri methods

我们作出的选择有不确定的后果。在某些情况下，不同的可能结果的概率是精确已知的，称为"高风险"的条件。在其他情况下无法估计概率，这是一个条件描述为"暧昧"。虽然大多数人都厌恶风险和歧义1,2，那些厌恶的程度有很大的不同个人，这样的主观价值的相同风险或不明确的选项，可以为不同的个体有很大的不同。我们结合了功能性磁共振成像（fMRI）技术与基于实验经济学方法来评估神经代表性的主观价值风险和不明确的选项4。这种技术可以用来研究神经表征在不同的人群，如不同年龄组和不同的患者人群。 在我们的实验中，受试者作出相应的选择between两种选择，而他们的神经激活使用功能磁共振成像跟踪。在每个试验中，受试者选择不同的彩票，在他们的货币量，无论是在与获奖相关的概率赢得该金额的或歧义水平的。我们的参数化设计，使我们能够利用每个人的选择行为，估计其对风险和模糊的态度，并以此估计，每一个方案为他们举行的主观价值。设计的另一个重要特征是所选择的彩票，结果没有透露在实验过程中，让没有学习的地方，和模棱两可的选项仍然是不明确的，风险的态度是稳定的。相反，在一个或几个试验结束扫描会话随机选择和演奏为真正的金钱。由于受试者事先不知道将选择的试验，他们必须认真对待每一个试验如果它是一个试验，他们将支付。这种设计的连接确保我们可以估算出每个选项的主观价值的每个主题。然后，我们看的区域在大脑中的激活相关的风险选项的主观价值和地区的激活相关的主观价值模棱两可的选项。

Watch this Scientific Journal Video about Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods at JoVE.com

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

使用功能磁共振成像和行为方式的主观价值在人类大脑中的风险和不明确的选项，以确定神经表示。

，测量主观价值风险和不明确的选项，使用实验经济学和功能磁共振成像的方法

Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition ...

measuring-subjective-value-risky-ambiguous-options-using-experimental

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

12.0K 次观看.  Yale School of Medicine. 使用功能磁共振成像和行为方式的主观价值在人类大脑中的风险和不明确的选项，以确定神经表示。

视频: Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in rodents have shown a direct link between testosterone and aggressive behavior1 and folk wisdom adapts these findings to humans, suggesting that testosterone induces antisocial, egoistic or even aggressive behavior2. However, many researchers doubt a direct testosterone-aggression link in humans, arguing instead that testosterone is primarily involved in status-related behavior3,4. As a high status can also be achieved by aggressive and antisocial means it can be difficult to distinguish between anti-social and status seeking behavior.
We therefore set up an experimental environment, in which status can only be achieved by prosocial means. In a double-blind and placebo-controlled experiment, we administered a single sublingual dose of 0.5 mg of testosterone (with a hydroxypropyl-&beta;-cyclodextrin carrier) to 121 women and investigated their social interaction behavior in an economic bargaining paradigm. Real monetary incentives are at stake in this paradigm; every player A receives a certain amount of money and has to make an offer to another player B on how to share the money. If B accepts, she gets what was offered and player A keeps the rest. If B refuses the offer, nobody gets anything. A status seeking player A is expected to avoid being rejected by behaving in a prosocial way, i.e. by making higher offers.
The results show that if expectations about the hormone are controlled for, testosterone administration leads to a significant increase in fair bargaining offers compared to placebo. The role of expectations is reflected in the fact that subjects who report that they believe to have received testosterone make lower offers than those who say they believe that they were treated with a placebo. These findings suggest that the experimental economics approach is sensitive for detecting neurobiological effects as subtle as those achieved by administration of hormones. Moreover, the findings point towards the importance of both psychosocial as well as neuroendocrine factors in determining the influence of testosterone on human social behavior.

The procedure described in this protocol shows that testosterone administration and folk beliefs about testosterone may be associated with directly opposed social behaviors.

睾酮和社会决策，结合行为内分泌和实验经济学:

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in ...

科研

神经科学

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

There are many unanswered questions about cerebral lateralization. In particular, it remains unclear which aspects of language and nonverbal ability are lateralized, whether there are any disadvantages associated with atypical patterns of cerebral lateralization, and whether cerebral lateralization develops with age. In the past, researchers interested in these questions tended to use handedness as a proxy measure for cerebral lateralization, but this is unsatisfactory because handedness is only a weak and indirect indicator of laterality of cognitive functions1. Other methods, such as fMRI, are expensive for large-scale studies, and not always feasible with children2.
Here we will describe the use of functional transcranial Doppler ultrasound (fTCD) as a cost-effective, non-invasive and reliable method for assessing cerebral lateralization. The procedure involves measuring blood flow in the middle cerebral artery via an ultrasound probe placed just in front of the ear. Our work builds on work by Rune Aaslid, who co-introduced TCD in 1982, and Stefan Knecht, Michael Deppe and their colleagues at the University of M&uuml;nster, who pioneered the use of simultaneous measurements of left- and right middle cerebral artery blood flow, and devised a method of correcting for heart beat activity. This made it possible to see a clear increase in left-sided blood flow during language generation, with lateralization agreeing well with that obtained using other methods3.
The middle cerebral artery has a very wide vascular territory (see Figure 1) and the method does not provide useful information about localization within a hemisphere. Our experience suggests it is particularly sensitive to tasks that involve explicit or implicit speech production. The 'gold standard' task is a word generation task (e.g. think of as many words as you can that begin with the letter 'B') 4, but this is not suitable for young children and others with limited literacy skills. Compared with other brain imaging methods, fTCD is relatively unaffected by movement artefacts from speaking, and so we are able to get a reliable result from tasks that involve describing pictures aloud5,6. Accordingly, we have developed a child-friendly task that involves looking at video-clips that tell a story, and then describing what was seen.

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound fTCD

Functional transcranial Doppler sonography (fTCD) is a simple and non-invasive ultrasound technique which can be used to assess the lateralization of cognitive functions, especially language, and is suitable for use with children.

儿童使用功能经颅多普勒超声评估大脑偏侧（fTCD）

There are many unanswered questions about cerebral lateralization.  In particular, it remains unclear which aspects of language and nonverbal ability are ...

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon measuring activity on the surface of cerebral cortex rather than in subcortical regions such as midbrain and brainstem. Subcortical fMRI must overcome two challenges: spatial resolution and physiological noise. Here we describe an optimized set of techniques developed to perform high-resolution fMRI in human SC, a structure on the dorsal surface of the midbrain; the methods can also be used to image other brainstem and subcortical structures.
High-resolution (1.2 mm voxels) fMRI of the SC requires a non-conventional approach. The desired spatial sampling is obtained using a multi-shot (interleaved) spiral acquisition1. Since, T2* of SC tissue is longer than in cortex, a correspondingly longer echo time (TE ~ 40 msec) is used to maximize functional contrast. To cover the full extent of the SC, 8-10 slices are obtained. For each session a structural anatomy with the same slice prescription as the fMRI is also obtained, which is used to align the functional data to a high-resolution reference volume.
In a separate session, for each subject, we create a high-resolution (0.7 mm sampling) reference volume using a T1-weighted sequence that gives good tissue contrast. In the reference volume, the midbrain region is segmented using the ITK-SNAP software application2. This segmentation is used to create a 3D surface representation of the midbrain that is both smooth and accurate3. The surface vertices and normals are used to create a map of depth from the midbrain surface within the tissue4.
Functional data is transformed into the coordinate system of the segmented reference volume. Depth associations of the voxels enable the averaging of fMRI time series data within specified depth ranges to improve signal quality. Data is rendered on the 3D surface for visualization.
In our lab we use this technique for measuring topographic maps of visual stimulation and covert and overt visual attention within the SC1. As an example, we demonstrate the topographic representation of polar angle to visual stimulation in SC.

This article describes techniques to perform high-resolution functional magnetic resonance imaging with 1.2 mm sampling in human midbrain and subcortical structures using a 3T scanner. Use of these techniques to resolve topographic maps of visual stimulation in the human superior colliculus (SC) is given as an example.

高分辨率人类中脑功能磁共振成像方法

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon ...

Methods to Assay Drosophila Behavior

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular disease and various neurological diseases1. We have optimized simple and robust behavioral assays for determining larval locomotion, adult climbing ability (RING assay), and courtship behaviors of Drosophila. These behavioral assays are widely applicable for studying the role of genetic and environmental factors on fly behavior. Larval crawling ability can be reliably used for determining early stage changes in the crawling abilities of Drosophila larvae and also for examining effect of drugs or human disease genes (in transgenic flies) on their locomotion. The larval crawling assay becomes more applicable if expression or abolition of a gene causes lethality in pupal or adult stages, as these flies do not survive to adulthood where they otherwise could be assessed. This basic assay can also be used in conjunction with bright light or stress to examine additional behavioral responses in Drosophila larvae. Courtship behavior has been widely used to investigate genetic basis of sexual behavior, and can also be used to examine activity and coordination, as well as learning and memory. Drosophila courtship behavior involves the exchange of various sensory stimuli including visual, auditory, and chemosensory signals between males and females that lead to a complex series of well characterized motor behaviors culminating in successful copulation. Traditional adult climbing assays (negative geotaxis) are tedious, labor intensive, and time consuming, with significant variation between different trials2-4. The rapid iterative negative geotaxis (RING) assay5 has many advantages over more widely employed protocols, providing a reproducible, sensitive, and high throughput approach to quantify adult locomotor and negative geotaxis behaviors. In the RING assay, several genotypes or drug treatments can be tested simultaneously using large number of animals, with the high-throughput approach making it more amenable for screening experiments.

Methods to Assay Drosophila Behavior

Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century 1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.

对检测方法果蝇行为

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular ...

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

使用超声波血脑屏障破坏和锰增强MRI的脑功能成像

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Optogenetic Functional MRI

The investigation of the functional connectivity of precise neural circuits across the entire intact brain can be achieved through optogenetic functional magnetic resonance imaging (ofMRI), which is a novel technique that combines the relatively high spatial resolution of high-field fMRI with the precision of optogenetic stimulation. Fiber optics that enable delivery of specific wavelengths of light deep into the brain in vivo are implanted into regions of interest in order to specifically stimulate targeted cell types that have been genetically induced to express light-sensitive trans-membrane conductance channels, called opsins. fMRI is used to provide a non-invasive method of determining the brain's global dynamic response to optogenetic stimulation of specific neural circuits through measurement of the blood-oxygen-level-dependent (BOLD) signal, which provides an indirect measurement of neuronal activity. This protocol describes the construction of fiber optic implants, the implantation surgeries, the imaging with photostimulation and the data analysis required to successfully perform ofMRI. In summary, the precise stimulation and whole-brain monitoring ability of ofMRI are crucial factors in making ofMRI a powerful tool for the study of the connectomics of the brain in both healthy and diseased states.

This protocol describes the steps and data analysis required to successfully perform optogenetic functional magnetic resonance imaging (ofMRI). ofMRI is a novel technique that combines high-field fMRI readout with optogenetic stimulation, allowing for cell type-specific mapping of functional neural circuits and their dynamics across the whole living brain.

光遗传学功能磁共振成像

The investigation of the functional connectivity of precise neural circuits across the entire intact brain can be achieved through optogenetic functional ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

经颅磁刺激在线联合方法对经颅交流电刺激对原发性运动皮层的影响

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

A Simple Approach to Induce Experimental Autoimmune Neuritis in C57BL/6 Mice for Functional and Neuropathological Assessments

Experimental autoimmune neuritis (EAN) is a well-appreciated experimental model of autoimmune peripheral demyelinating diseases. EAN disease is induced by immunizing mice with neurogenic peptides to direct an inflammatory attack toward components of the peripheral nervous system (PNS). Recent advances have enabled the induction of EAN in the relatively resistant C57BL/6 mouse line using myelin protein zero (P0)106-125 or P0180-199 peptides delivered in adjuvant combined with the injection of pertussis toxin. The ability to induce EAN in the C57BL/6 strain allows for the use of the numerous genetic tools that exist on this mouse background, and thus allows the sophisticated study of disease pathogenesis and interrogation of the mechanistic action of novel therapeutics in combination with transgenic approaches. In this study, we demonstrate a simple approach to successfully induce EAN using the P0180-199 peptide in C57BL/6 mice. We also outline a protocol for the assessment of functional deficits that occur in this model, accompanied by an array of neuropathological features. Thus, this model is a powerful experimental model to study the pathogenesis of human peripheral demyelinating neuropathies, and to determine the efficacy of potential therapies that aim to promote myelin repair and protect against nerve damage in autoimmune neuritis.

This report outlines a simple approach to successfully induce experimental autoimmune neuritis (EAN) using the myelin protein zero (P0)180-199 peptide in combination with Freund&#39;s complete adjuvant and pertussis toxin. We present a sophisticated paradigm capable of accurately assessing the extent of functional deficits and neuropathology that occur in this EAN.

C57BL/6 小鼠自身免疫性神经炎的功能和病理评价的简易方法

Experimental autoimmune neuritis (EAN) is a well-appreciated experimental model of autoimmune peripheral demyelinating diseases. EAN disease is induced by ...

Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of benign and malignant lesions through a natural anatomical extra-cranial pathway, represented by the nasal cavities, avoiding brain retraction and neurovascular manipulation. This is reflected by the patients' prompt clinical recovery and the low risk of permanent neurological sequelae, representing the main caveat of conventional skull base surgery. This surgery must be tailored to each specific case, considering its features and relationship with surrounding neural structures, mostly based on preoperative neuroimaging. Advanced MRI techniques, such as tractography, have been rarely adopted in skull base surgery due to technical issues: lengthy and complicated processes to generate reliable reconstructions for inclusion in the neuronavigation system. 
This paper aims to present the protocol implemented in the institution and highlights the synergistic collaboration and teamwork between neurosurgeons and the neuroimaging team (neurologists, neuroradiologists, neuropsychologists, physicists, and bioengineers) with the final goal of selecting the optimal treatment for each patient, improving the surgical results and pursuing the advancement of personalized medicine in this field.

We present a protocol to integrate diffusion MRI tractography in patient work-up to endoscopic endonasal surgery for a skull base tumor. The methods for adopting these neuroimaging studies in the pre- and intra-operative phases are described.

扩散MRI造影术在内窥镜内窥镜颅骨基础外科中的作用

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of ...

Reliable Acquisition of Electroencephalography Data during Simultaneous Electroencephalography and Functional MRI

Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), EEG-fMRI, combines the complementary properties of scalp EEG (good temporal resolution) and fMRI (good spatial resolution) to measure neuronal activity during an electrographic event, through hemodynamic responses known as blood-oxygen-level-dependent (BOLD) changes. It is a non-invasive research tool that is utilized in neuroscience research and is highly beneficial to the clinical community, especially for the management of neurological diseases, provided that proper equipment and protocols are administered during data acquisition. Although recording EEG-fMRI is apparently straightforward, the correct preparation, especially in placing and securing the electrodes, is not only important for safety but is also critical in ensuring the reliability and analyzability of the EEG data obtained. This is also the most experience-demanding part of the preparation. To address these issues, a straightforward protocol that ensures data quality was developed. This article provides a step-by-step guide for acquiring reliable EEG data during EEG-fMRI using this protocol that utilizes readily available medical products. The presented protocol can be adapted to different applications of EEG-fMRI in research and clinical settings, and may be beneficial to both inexperienced and expert operators.

This article provides a straightforward protocol for acquiring good quality electroencephalography (EEG) data during simultaneous EEG and functional magnetic resonance imaging by utilizing readily available medical products.

同时脑电图和功能 MRI 期间的可靠脑成像数据获取

Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), EEG-fMRI, combines the complementary properties of scalp EEG ...