We thank the VISTA software group (Brian Wandell and associates, at Stanford).
S. S. was supported by McNair 2280403105,NEI R01-EY109272, and NEI R01-EY024019 and as HHMI Early Carrer Award. A. P. and G. K. was supported by the Max-Planck Society, G. K. was supported by the PLASTICISE project of the 7th Framework Programme of the European Commission, Contract no. HEATH-F2-2009-223524.

1.数据采集<ol><li>制备刺激协议是有效的如先前在迪穆兰和万德尔1和Lee 等人所述引出一个可靠初级视视觉响应。2。然而，其他公认的范例也适用视具体实验问题有待解决。 </li><li>本栏刺激飘过屏幕顺序地沿着空间8个方向，步长为45度。确保该运动是同步地与扫描框采集（TR〜2秒），以使杆移动一次一个步骤的功能磁共振成像帧开始，并保持在新的位置，直到该帧结束。 </li><li>衡量一个正确的基准信号，没有酒吧刺激1加时代。 <ol><li>定义的图（10至15°半径）在视觉角度在其上的刺激呈现一个字段。目前移动或抖动棋盘图案（方格大小为0.94 x 0.94英寸度2，patte酒吧内的氡更新率= 250毫秒/模式），以引起强烈的视觉反应。 </li><li>输入以下具体参数：8均匀分布的运动方向，条宽等于1.875度，和酒吧将通过每帧（2秒）半条宽。额外的细节可以在Lee 等人的发现。2。 </li><li>产生在屏幕中心上的实验过程中拍摄对象的眼睛注视一个点（0.25〜°）。在一次随意改变现货颜色。 </li></ol></li><li>扫描使用典型回波平面成像（EPI）扫描具有192帧的持续时间（在运动的每个方向上24帧）在MRI扫描器受试者的脑。重复扫描的4-8倍，以增加信噪比。 </li><li>集参数的EPI顺序如下：TR = 2秒，TE = 40毫秒，矩阵尺寸= 64×64，28片，体素大小= 3×3×3mm的3，翻转角= 90°，或者，应用序列以更高的分辨率（ 如克，2×2×2mm的3）或一短TR（ 例如 ，1-1.5秒）仅覆盖视觉皮层2。 </li><li>追踪眼球运动过程中与扫描功能的眼球追踪系统，以确保固定的保持在固定点的1-1.5度。 注意：在此，头部的坐标基于眼球追踪在目镜系统中被使用，但其它合适的眼球追踪系统可以用来代替。 </li><li>指导受试者注视在步骤1.3.2中产生的屏幕中心的位置。为了确保受试者的行了吧，指导他们报告固定点的色彩变化。 </li><li>获得解剖扫描，在1×1×1毫米3分辨率（ 例如 ，T1-MPRAGE; TR = 1900毫秒，TE = 2.26毫秒，TI = 900毫秒，翻转角= 11°，176分区）。 注意：这些解剖扫描将用于分割以及用于内和跨扫描对准功能图像的解剖结构。对于功能之间进行更好的调整人（EPI）的图像和解剖，还获得面内解剖扫描，具有对EPI的分辨率相同，使用T1加权快速扰梯度回波（SPGR）序列1。 </li></ol> 2.数据预处理注意：在此之前推定PRF性能，需要几个典型的fMRI数据前处理步骤，如头部运动校正和功能的卷的解剖扫描对准。在这篇文章中，得到的结果都预处理，估计，分析和表达所使用的开放源码基于MATLAB软件工具箱VISTA LAB可在VISTA软件的网站进行。 http://white.stanford.edu/newlm/index.php/Main_Page。 <ol><li>加载解剖扫描到MATLAB和使用称为createVolAnat功能准备卷解剖。 </li><li>段灰质，白质和CSF使用功能“ItkGray”。 </li><li>通过转换DICOM准备功能的数据（ 即 </e使用一种称为mrInit功能M&gt;，西门子原始MRI文件格式）文件转换成NIFTI（ 即标准的功能性磁共振成像文件格式）文件，并加载数据到VISTA。 </li><li>正确的头部运动和调整功能图像使用rxAlign基于仿射矩阵变换步骤2.1加载的解剖。 </li><li>平均官能运动校正的扫描用于改善信噪比通过点击mrVISTA分析时间序列的平均TSERIES。从平均扫描期间，眼球运动，从固定偏差超过1-1.5度排除。如果从不同的运行信号具有不同的直流漂移，去除直流漂移后平均官能扫描。 </li><li>计算功能扫描和灰质的贴图坐标，并通过选择以下菜单识别功能的扫描相应的灰质体素：mrVISTA窗口打开灰三视图窗口。在灰质像素插值​​分配BOLD信号，选择的选项之一vailable在mrVISTA。 </li></ol> 3.估计PRF地形和参数化建模<ol><li>通过下面的链接下载的代码文件：https://sites.google.com/site/leesangkyun/prf/codes.zip，解压压缩文件并将其放置在本地计算机的首选地点。添加在MATLAB的文件夹的路径。 </li><li>设置通过选择以下菜单用于实验的刺激参数：mrVISTA分析初级视模式设置参数。指定以下参数，如刺激图象，刺激大小，典型的血液动力学功能，功能磁共振成像扫描仪的帧速率。 </li><li>在此之前的PRF的估计，准备初始参数集（ 图1B）。 <ol><li>从代码文件设置的交叉验证集“tprf_set_params.m”。除法时间序列划分成至少两个子集（一组用于测试和训练剩余集）是足够长的条来SWEEP整个刺激的空间。可替代地，如果没有在步骤2.4平均扫描，通过省去一次扫描进行检测，并使用剩余的扫描训练验证扫描。 </li><li>设置一个粗参数集（λ在图1中;λ= [10 -2 10 -1 1 10 1 10 2]）中的“tprf_set_params.m”。然后，树立了良好的规模范围（[0.1 0.3 0.5 0.7 0.9 1 3 5 7 9]）在“tprf_set_params.m”。 注：本方案采用粗集选择导致最高解释方差的λ。然后，程序搜索使用精细尺度范围围绕所选λ的空间，进一步细化λ的产生最高解释方差选择。 </li><li>对于在“tprf_set_params.m”视觉响应的体素设定解释方差的阈值（0.2）。 注意：此阈值被用作用于选择的视觉响应的体素基准。另外，作出投资回报率的非视觉响应区（ 例如 ，通过绘制一个球体为1厘米的非视觉响应脑区域的半径），其中所述阈值可以自动计算。 </li><li>设置一组阈值（[0.3，0.5，0.7]），用于限定PRF中心区域中的归一化地形“tprf_set_params.m”（ 即 ，[0-1]或[-1至1]与历元无杆刺激在步骤1.3.1）。 注意：从设定的阈值的规定的程序选择“最好”的阈值， 也就是说 ，它定义为其中PRF中心模型解释了最大信号方差一个PRF中心区域的阈值。另外，选择不同的设置根据地形特点的阈值。 </li></ol></li><li>执行“tprf_runpRFest.m”计算PRF形貌（ 图1）和适合的2D各向异性高斯。指定在本协议中所描述的所有参数后，和运行代码，得到最终的估计结果。 </li></ol><img alt="图1" src="/files/ftp_upload/51811/51811fig1highres.jpg" width="700" /> 图1：PRF估计处理。 （A）的过程示意图遵循PRF地形估计H（T）：血流动力学响应函数，A（T）：刺激，M：PRF，注册：L2范数正规化（B）的具体步骤PRF地形估计和PRF中心模型。集所需的估计参数中列出的每个步骤。地形和模型的一维节中说明。在“模型拟合”，黑色和红色的曲线代表了地形和0.5，分别为中心的阈值PRF中心模式。蓝色虚线表示的PRF阈值中部地区。

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The authors declare that they have no competing financial interests.

本文演示了如何估计在人类视觉皮层以及如何使用它来选择感受野适当的参数化模型可视化人口感受野的地形。对于一个成功的retinotopy，一个适当的刺激方案和有效的分析方法，应选择，和被检者的实验参数（运动和固定）应该被优化。酒吧的刺激依次穿过视野运动是一种有效的刺激范式PRF估计，因为它产生区别于刺激的地点不同的BOLD响应。所提供的方法构建PRF地形。自PRF估计问题通常是根据?...

功能性磁共振成像（fMRI）测量非侵入视皮层中的宏观尺度的功能组织（通常在几毫米的数量级）。早期的功能磁共振成像研究retinotopy用于刺激位置之间的连贯性的措施，引起BOLD反应4-7。这些研究通常没有估计总体感受野大小。以后，迪穆兰和万德尔1提出明确建模的PRF的位置和大小，利用该模型的一个线性函数来预测BOLD反应来克服这种限制的方法。然而，这一开创性方法的一个限制是该参数PRF模型必须选择一个先验，并可能导致错误的PRF估计，如果它原来不恰当。 为了克服参数PRF-模型方法的局限性，新方法最近已开发的。这些方法直接预测到S的BOLD响应timulus通过重构PRF地形。建议由格林和他的同事的方法8重建PRF地形通过背投影BOLD响应个别维刺激空间，建设PRF地形就像一个典型的计算机断层扫描技术的2D刺激的空间。另一方面，我们提出的方法2直接估计2D PRF地形通过使用线性回归和施加一个正则化技术。在该方法中，PRF地形被表示为一组权值被乘以的刺激来估计给定体素的神经元群的响应。那么，最后的血氧水平依赖（BOLD）响应的刺激诱发估计通过卷积神经元群的响应和规范的血流动力学响应函数。为了解决上述下约束线性系统，此外，岭回归正规化用于强制稀疏（ 见图1下文）。正规化技术抑制噪音和伪影，从而使我们的方法，以更有力估计PRF地形。 地形方法不强制PRF形状有一定的参数形状，因此可以发现实际PRF结构。适当的参数化模型然后可以基于该PRF地形选择。例如，该PRF形貌可以用于分离PRF中心和环绕，然后随后的PRF中心建模可通过最大限度地减少环绕抑制在遥远的区域中出现的其他潜在伪影的影响的影响，以及更准确PRF中心。我们最近完成我们的方法，直接几种其他方法之间的定量比较（ 即估计地形之前）适合各向同性高斯1，各向异性高斯和各向同性高斯差到PRF 9。人们发现，在topography为基础的方法优于这些方法相对于PRF中心建模通过实现更高的解释BOLD信号时序的变化。 PRF特性在各个领域的精确估计揭示他们如何覆盖视野，是研究视觉皮层特别是因为它涉及到视觉感知的功能组织重要。性能，如如何与偏心1,10和PRF中心环绕组织9 PRF尺寸变化很好的研究，在人类文学。所提出的方法用于估计PRF地形导致更准确的PRF的参数建模和更可能揭示未知规律，不容易建模的先验在直接参数化模型。这种做法将特别适合学习PRF组织患者视觉通路病变，对他们来说，PRF结构也不一定能够预测先验。下面描述如何估计第ËPR​​F地形以及如何使用地形的PRF中心模式。

<table border="0" cellpadding="0" cellspacing="0" width="1009">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:225px;">Name of Equipment/Software</td>
			<td style="width:219px;">Company/Provider</td>
			<td style="width:219px;"></td>
			<td style="width:347px;">Web address</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MRI scanner</td>
			<td>Siemens/Philips/GE</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MATLAB</td>
			<td>The Mathworks, Inc.</td>
			<td></td>
			<td>http://www.mathworks.com&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">VISTA software</td>
			<td>VISTA software group</td>
			<td></td>
			<td>http://white.stanford.edu/newlm/index.php/Software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PsychoToolbox</td>
			<td>PsychoToolbox&#160;</td>
			<td></td>
			<td>http://psychtoolbox.org&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Eye Tracker(VisuaStimDigital)</td>
			<td>Resonance Technology Inc</td>
			<td></td>
			<td>http://mrivideo.com/</td>
		</tr>
	</tbody>
</table>

topographical estimation of visual population receptive fields by fmri

视觉皮层retinotopically组织使得细胞群相邻映射到视场的相邻部件。功能性磁共振成像使我们能够估计基于体素的人口感受域（PRF）， 即 ，视场激活每个体素中的细胞的一部分。之前，直接，PRF估计方法1遭受一定的局限性：1）PRF模型被选择的先验和可能不完全捕获实际的PRF的形状，和2）PRF中心是容易发生的刺激空间的边界附近的错误定位。在这里，一个新的地形PRF估计方法2建议在很大程度上规避这些限制。线性模型被用来通过卷积PRF到视觉刺激与规范的血流动力学响应函数的线性响应预测血氧水平依赖（BOLD）信号。 PRF地形被表示为权重向量，其分量所代表的STR素神经元的总响应ength来刺激呈现在不同的视野位置。由此产生的线性方程组可以解决使用岭回归3 PRF的权重向量，产生PRF地形。一个匹配于所估计的地形是一个PRF，模型然后可以选择事后，由此提高PRF的参数，如PRF-中心位置，PRF方向，大小等的估算值。具有PRF形貌可用也允许的PRF的参数估计，允许各种PRF性质的提取的视觉验证，而不必做出关于PRF结构的先验假设。这种方法有望成为调查的患者的PRF组织与视觉系统的疾病特别有用。

准确的PRF建模需要正确捕捉PRF形状。不知道PRF地形，圆对称模型之前的研究1,9-11使用的选择是合理的选择。这是因为，如果本地初级视组织具有同样的视场的所有方向中，当地居民的反应可以表示为神经元响应一个圆对称的累积总和。然而，我们的观察表明，这不是必须的情况下（ 图2）。因此，观察PRF地形的可用于一个PRF模型选择一个适当的参数函数的关键。这就是PRF地形?...

Watch this Scientific Journal Video about Topographical Estimation of Visual Population Receptive Fields by fMRI at JoVE.com

Topographical Estimation of Visual Population Receptive Fields by fMRI

It is important to obtain unbiased estimates of visual population receptive fields (pRFs) by functional magnetic resonance imaging. We use mild regularization constraints to estimate pRF topography without a-priori assumptions about pRF shape, allowing us to choose specific pRF models post-hoc. This is particularly advantageous in subjects with visual-pathway lesions.

人口视觉感受野由功能磁共振成像地形估计

Visual cortex is retinotopically organized so that neighboring populations of cells map to neighboring parts of the visual field. Functional magnetic ...

topographical-estimation-of-visual-population-receptive-fields-by-fmri

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9.2K 次观看.  Baylor College of Medicine. It is important to obtain unbiased estimates of visual population receptive fields (pRFs) by functional magnetic resonance imaging. We use mild regularization constraints to estimate pRF topography without a-priori assumptions about pRF shape, allowing us to choose specific pRF models post-hoc. This is particularly advantageous in subjects with visual-pathway lesions.

视频: Topographical Estimation of Visual Population Receptive Fields by fMRI

Functional Magnetic Resonance Imaging (fMRI) with Auditory Stimulation in Songbirds

The neurobiology of birdsong, as a model for human speech, is a pronounced area of research in behavioral neuroscience. Whereas electrophysiology and molecular approaches allow the investigation of either different stimuli on few neurons, or one stimulus in large parts of the brain, blood oxygenation level dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) allows combining both advantages, i.e. compare the neural activation induced by different stimuli in the entire brain at once. fMRI in songbirds is challenging because of the small size of their brains and because their bones and especially their skull comprise numerous air cavities, inducing important susceptibility artifacts. Gradient-echo (GE) BOLD fMRI has been successfully applied to songbirds 1-5 (for a review, see 6). These studies focused on the primary and secondary auditory brain areas, which are regions free of susceptibility artifacts. However, because processes of interest may occur beyond these regions, whole brain BOLD fMRI is required using an MRI sequence less susceptible to these artifacts. This can be achieved by using spin-echo (SE) BOLD fMRI 7,8 . In this article, we describe how to use this technique in zebra finches (Taeniopygia guttata), which are small songbirds with a bodyweight of 15-25 g extensively studied in behavioral neurosciences of birdsong. The main topic of fMRI studies on songbirds is song perception and song learning. The auditory nature of the stimuli combined with the weak BOLD sensitivity of SE (compared to GE) based fMRI sequences makes the implementation of this technique very challenging.

Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds

This article shows an optimized procedure for imaging of the neural substrates of auditory stimulation in the songbird brain using functional Magnetic Resonance Imaging (fMRI). It describes the preparation of the sound stimuli, the positioning of the subject and the acquisition and subsequent analysis of the fMRI data.

功能磁共振成像（fMRI）技术与听觉刺激鸣禽

The neurobiology of birdsong, as a model for human speech, is a pronounced area of research in behavioral neuroscience. Whereas electrophysiology and ...

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Best Current Practice for Obtaining High Quality EEG Data During Simultaneous fMRI

Simultaneous EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the high spatial accuracy of fMRI. The data from these two modalities can be combined in a number of ways, but all rely on the acquisition of high quality EEG and fMRI data. EEG data acquired during simultaneous fMRI are affected by several artifacts, including the gradient artefact (due to the changing magnetic field gradients required for fMRI), the pulse artefact (linked to the cardiac cycle) and movement artifacts (resulting from movements in the strong magnetic field of the scanner, and muscle activity). Post-processing methods for successfully correcting the gradient and pulse artifacts require a number of criteria to be satisfied during data acquisition. Minimizing head motion during EEG-fMRI is also imperative for limiting the generation of artifacts.
Interactions between the radio frequency (RF) pulses required for MRI and the EEG hardware may occur and can cause heating. This is only a significant risk if safety guidelines are not satisfied. Hardware design and set-up, as well as careful selection of which MR sequences are run with the EEG hardware present must therefore be considered.
The above issues highlight the importance of the choice of the experimental protocol employed when performing a simultaneous EEG-fMRI experiment. Based on previous research we describe an optimal experimental set-up. This provides high quality EEG data during simultaneous fMRI when using commercial EEG and fMRI systems, with safety risks to the subject minimized. We demonstrate this set-up in an EEG-fMRI experiment using a simple visual stimulus. However, much more complex stimuli can be used. Here we show the EEG-fMRI set-up using a Brain Products GmbH (Gilching, Germany) MRplus, 32 channel EEG system in conjunction with a Philips Achieva (Best, Netherlands) 3T MR scanner, although many of the techniques are transferable to other systems.

Simultaneous electroencephalography (EEG) and functional Magnetic Resonance imaging (fMRI) is a powerful neuroimaging tool. However, the inside of an MRI scanner forms a difficult environment for EEG data recording and safety must be considered whenever operating EEG equipment inside a scanner. Here, we present an optimised EEG-fMRI data acquisition protocol.

获得高质量的脑电数据在同步功能磁共振成像的当前最佳实践

Simultaneous  EEG-fMRI allows the excellent temporal resolution of EEG to be combined with the  high spatial accuracy of fMRI. The data  from these two ...

fMRI Validation of fNIRS Measurements During a Naturalistic Task

We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced version of the task using fMRI (functional magnetic resonance imaging). Recently, it has been shown that fNIRS can accurately record functional brain activities equivalent to those concurrently recorded with functional magnetic resonance imaging for classic psychophysical tasks and simple finger tapping paradigms. However, an often quoted benefit of fNIRS is that the technique allows for studying neural mechanisms of complex, naturalistic behaviors that are not possible using the constrained environment of fMRI. Our goal was to extend the findings of previous studies that have shown high correlation between concurrently recorded fNIRS and fMRI signals to compare neural recordings obtained in fMRI procedures to those separately obtained in naturalistic fNIRS experiments. Specifically, we developed a modified version of the dance video game Dance Dance Revolution (DDR) to be compatible with both fMRI and fNIRS imaging procedures. In this methodology we explain the modifications to the software and hardware for compatibility with each technique as well as the scanning and calibration procedures used to obtain representative results. The results of the study show a task-related increase in oxyhemoglobin in both modalities and demonstrate that it is possible to replicate the findings of fMRI using fNIRS in a naturalistic task. This technique represents a methodology to compare fMRI imaging paradigms which utilize a reduced-world environment to fNIRS in closer approximation to naturalistic, full-body activities and behaviors. Further development of this technique may apply to neurodegenerative diseases, such as Parkinson&#8217;s disease, late states of dementia, or those with magnetic susceptibility which are contraindicated for fMRI scanning.

We present a method to compare functional brain activity recorded during a naturalistic task using fNIRS with activity recorded during fMRI.

的fNIRS功能磁共振成像测量验证过程中一个自然主义任务

We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced ...

Methods to Test Visual Attention Online

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative data samples than can typically be collected on college campuses. However, before such methods can be widely adopted, a number of technological challenges must be overcome &#8211; in particular in experiments where tight control over stimulus properties is necessary. Here we present methods for collecting performance data on two tests of visual attention. Both tests require control over the visual angle of the stimuli (which in turn requires knowledge of the viewing distance, monitor size, screen resolution, etc.) and the timing of the stimuli (as the tests involve either briefly flashed stimuli or stimuli that move at specific rates). Data collected on these tests from over 1,700 online participants were consistent with data collected in laboratory-based versions of the exact same tests. These results suggest that with proper care, timing/stimulus size dependent tasks can be deployed in web-based settings.

To replicate laboratory settings, online data collection methods for visual tasks require tight control over stimulus presentation. We outline methods for the use of a web application to collect performance data on two tests of visual attention.

方法在线测试视觉注意

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative ...

Visualizing Visual Adaptation

Many techniques have been developed to visualize how an image would appear to an individual with a different visual sensitivity: e.g., because of optical or age differences, or a color deficiency or disease. This protocol describes a technique for incorporating sensory adaptation into the simulations. The protocol is illustrated with the example of color vision, but is generally applicable to any form of visual adaptation. The protocol uses a simple model of human color vision based on standard and plausible assumptions about the retinal and cortical mechanisms encoding color and how these adjust their sensitivity to both the average color and range of color in the prevailing stimulus. The gains of the mechanisms are adapted so that their mean response under one context is equated for a different context. The simulations help reveal the theoretical limits of adaptation and generate &#34;adapted images&#34; that are optimally matched to a specific environment or observer. They also provide a common metric for exploring the effects of adaptation within different observers or different environments. Characterizing visual perception and performance with these images provides a novel tool for studying the functions and consequences of long-term adaptation in vision or other sensory systems.

This article describes a novel method for simulating and studying adaptation in the visual system.

可视化视觉适应

Many techniques have been developed to visualize how an image would appear to an individual with a different visual sensitivity: e.g., because of optical ...

Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments

This protocol describes how to conduct temporal-order experiments to measure visual processing speed and the attentional resource distribution. The proposed method is based on a new and synergistic combination of three components: the temporal-order judgments (TOJ) paradigm, Bundesen&#39;s Theory of Visual Attention (TVA), and a hierarchical Bayesian estimation framework. The method provides readily interpretable parameters, which are supported by the theoretical and neurophysiological underpinnings of TVA. Using TOJs, TVA-based estimates can be obtained for a broad range of stimuli, whereas traditional paradigms used with TVA are mainly limited to letters and digits. Finally, the meaningful parameters of the proposed model allow for the establishment of a hierarchical Bayesian model. Such a statistical model allows assessing results in one coherent analysis both on the subject and the group level.
To demonstrate the feasibility and versatility of this new approach, three experiments are reported with attention manipulations in synthetic pop-out displays, natural images, and a cued letter-report paradigm.

Temporal-order judgments can be used to estimate processing speed parameters and attentional weights and thereby to infer the mechanisms of attentional processing. This methodology can be applied to a wide range of visual stimuli and works with many attention manipulations.

通过颞阶判决的基于模型的分析测量注意力和视觉处理速度

This protocol describes how to conduct temporal-order experiments to measure visual processing speed and the attentional resource distribution. The ...

fMRI Mapping of Brain Activity Associated with the Vocal Production of Consonant and Dissonant Intervals

The neural correlates of consonance and dissonance perception have been widely studied, but not the neural correlates of consonance and dissonance production. The most straightforward manner of musical production is singing, but, from an imaging perspective, it still presents more challenges than listening because it involves motor activity. The accurate singing of musical intervals requires integration between auditory feedback processing and vocal motor control in order to correctly produce each note. This protocol presents a method that permits the monitoring of neural activations associated with the vocal production of consonant and dissonant intervals. Four musical intervals, two consonant and two dissonant, are used as stimuli, both for an auditory discrimination test and a task that involves first listening to and then reproducing given intervals. Participants, all female vocal students at the conservatory level, were studied using functional Magnetic Resonance Imaging (fMRI) during the performance of the singing task, with the listening task serving as a control condition. In this manner, the activity of both the motor and auditory systems was observed, and a measure of vocal accuracy during the singing task was also obtained. Thus, the protocol can also be used to track activations associated with singing different types of intervals or with singing the required notes more accurately. The results indicate that singing dissonant intervals requires greater participation of the neural mechanisms responsible for the integration of external feedback from the auditory and sensorimotor systems than does singing consonant intervals.

The neural correlates of listening to consonant and dissonant intervals have been widely studied, but the neural mechanisms associated with production of consonant and dissonant intervals are less well known. In this article, behavioral tests and fMRI are combined with interval identification and singing tasks to describe these mechanisms.

功能磁共振成像映射与辅音和解调间隔的声音生成相关的脑活动

The neural correlates of consonance and dissonance perception have been widely studied, but not the neural correlates of consonance and dissonance ...

Automated Analysis of a Nematode Population-based Chemosensory Preference Assay

The nematode, Caenorhabditis elegans' compact nervous system of only 302 neurons underlies a diverse repertoire of behaviors. To facilitate the dissection of the neural circuits underlying these behaviors, the development of robust and reproducible behavioral assays is necessary. Previous C. elegans behavioral studies have used variations of a "drop test", a "chemotaxis assay", and a "retention assay" to investigate the response of C. elegans to soluble compounds. The method described in this article seeks to combine the complementary strengths of the three aforementioned assays. Briefly, a small circle in the middle of each assay plate is divided into four quadrants with the control and experimental solutions alternately placed. After the addition of the worms, the assay plates are loaded into a behavior chamber where microscope cameras record the worms' encounters with the treated regions. Automated video analysis is then performed and a preference index (PI) value for each video is generated. The video acquisition and automated analysis features of this method minimizes the experimenter's involvement and any associated errors. Furthermore, minute amounts of the experimental compound are used per assay and the behavior chamber's multi-camera setup increases experimental throughput. This method is particularly useful for conducting behavioral screens of genetic mutants and novel chemical compounds. However, this method is not appropriate for studying stimulus gradient navigation due to the close proximity of the control and experimental solution regions. It should also not be used when only a small population of worms is available. While suitable for assaying responses only to soluble compounds in its current form, this method can be easily modified to accommodate multimodal sensory interaction and optogenetic studies. This method can also be adapted to assay the chemosensory responses of other nematode species.

We present a behavior recording setup and protocol that enables automated analysis of the nematode, Caenorhabditis elegans' preference for soluble compounds in a population-based assay. This article describes the construction of a behavior chamber, the behavioral assay protocol, and video analysis software usage.

基于线虫人群的化学感应优选测定的自动分析

The nematode, Caenorhabditis elegans' compact nervous system of only 302 neurons underlies a diverse repertoire of behaviors. To facilitate the dissection ...

Visual Classical Conditioning in Wood Ants

Several species of insects have become model systems for studying learning and memory formation. Although many studies focus on freely moving animals, studies implementing classical conditioning paradigms with harnessed insects have been important for investigating the exact cues that individuals learn and the neural mechanisms underlying learning and memory formation. Here we present a protocol for evoking visual associative learning in wood ants through classical conditioning. In this paradigm, ants are harnessed and presented with a visual cue (a blue cardboard), the conditional stimulus (CS), paired with an appetitive sugar reward, the unconditional stimulus (US). Ants perform a Maxilla-Labium Extension Reflex (MaLER), the unconditional response (UR), which can be used as a readout for learning. Training consists of 10 trials, separated by a 5-minute intertrial interval (ITI). Ants are also tested for memory retention 10 minutes or 1 hour after training. This protocol has the potential to allow researchers to analyze, in a precise and controlled manner, the details of visual memory formation and the neural basis of learning and memory formation in wood ants.

We present a protocol for the classical conditioning of harnessed ants that permits researchers to study visual learning and memory formation at a level of analysis not possible with freely moving individuals.

木蚁视觉经典调理

Several species of insects have become model systems for studying learning and memory formation. Although many studies focus on freely moving animals, ...

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we recorded the eye position of human participants engaged in a saccade task via eye tracking and assessed visual orientation discrimination performance at various locations during saccade preparation. Importantly, instead of using a single saccade target paradigm for which the saccade endpoint typically coincides roughly with the target, this protocol comprised the presentation of two nearby saccade targets, leading to a distinct spatial dissociation between target locations and saccade endpoint on a substantial number of trials. The paradigm allowed us to compare presaccadic visual discrimination performance at the endpoint of accurate saccades (landing at one of the saccade targets) and of averaging saccades (landing at an intermediate location in between the two targets). We observed a selective enhancement of visual sensitivity at the endpoint of accurate saccades but not at the endpoint of averaging saccades. Rather, before the execution of averaging saccades, visual sensitivity was equally enhanced at both targets, suggesting that saccade averaging follows from unresolved attentional selection among the saccade targets. These results argue against a mandatory coupling between visual attention and saccade programming based on a direct measure of presaccadic visual sensitivity rather than saccadic reaction times, which have been used in other protocols to draw similar conclusions. While our protocol provides a useful framework to investigate the relationship between visual attention and saccadic eye movements at the behavioral level, it can also be combined with electrophysiological measures to extend insights at the neuronal level.

This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades.

通过视觉跟踪和视觉灵敏度评估, 探讨准确、平均的视频前视觉注意的部署

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we ...