Towards an Improved Understanding of BOLD Signal Changes

加深对 BOLD 信号变化的理解

• 批准号: 7802893
• 负责人: R Todd Constable
• 金额: $ 35.8万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-20 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7802893
• 关键词: Accounting; Action Potentials; Area; Back; Blood Vessels; Brain; Cerebrovascular Circulation; Cerebrum; Choices and Control; Cognition; Cognitive; Coupling; Data; Detection; Electrodes; Electroencephalography; Epilepsy; Frequencies; Functional Imaging; Functional Magnetic Resonance Imaging; Implanted Electrodes; Lead; Lesion; Link; Measures; Medial; Memory; Metabolic; Metabolism; Methods; Modeling; Nature; Neurons; Operative Surgical Procedures; Output; Oxygen; Oxygen Consumption; Patients; Physiological; Prefrontal Cortex; Process; Proxy; Relative (related person); Research Personnel; Short-Term Memory; Signal Transduction; Source; Steel; Stimulus; Surface; Synapses; Synaptic Potentials; Temporal Lobe; Testing; Time; Variant; Work; base; blood oxygen level dependent; cingulate cortex; cognitive function; extracellular; improved; information processing; insight; neocortical; neurophysiology; novel; programs; relating to nervous system; relational memory; research study; response

DESCRIPTION (provided by applicant): Sharp transients, in electrical recordings, represent a measure of neural activity corresponding to an action potential at a single neuron. Such spike activity reflects the output of a given brain area, yet many regions receive input in the form of excitatory or inhibitory synaptic potentials without generating spikes. This input activity is an important form of computational integration, detected in extracellular recordings as perturbations of the local field potential (LFP). Quantitative analysis of the LFP is performed in the frequency domain, providing a measure of synchronous activity across neurons. Logothetis et al. (2001) showed that BOLD may reflect an area's input in the form of synaptic potentials, rather than its output in the form of spikes. Synaptic inputs can be excitatory or inhibitory, and both forms involve metabolic demands that may alter BOLD and complicate models interpreting BOLD as a proxy for cognitive engagement. The time- courses of oscillations in various frequency bands, and excitatory and inhibitory synaptic potentials, and the relationship between these forms of activity and cognition as reflected by BOLD, is poorly understood. Thus, it is essential to examine the correspondence between certain forms of neural activity, BOLD, and the engagement of cognitive processes. Negative BOLD signals in some cases, for example, demand a nuanced interpretation. The subtractive nature of fMRI initially suggests that negative BOLD simply reflects increased activation during the baseline. However, a number of findings have suggested that negative BOLD represents a distinct phenomenon. This proposal is focused on examining the evidence that negative BOLD reflects decreases in neural activity, associated with cognition. Calibrated MR measures of BOLD and CBF will be performed using tasks previously shown to produce reliable deactivations. These MR measures of flow and oxygenation will be used to determine relative CMRO2 and the oxygen extraction to fully assess the physiologic underpinnings of BOLD. Simultaneous EEC will be recorded and EEC power in multiple frequency bands compared with the MR measures. Much work has been performed characterizing EEC changes in the tasks to be used, but little work has attempted to relate EEC to MR signals. This work will provide insight into the relationship between MR signal changes in cognitive tasks, and EEC changes as measured with surface, and in a limited number of patients, subdural electrodes.

描述（由申请人提供）：电记录中的尖锐瞬变代表与单个神经元的动作电位相对应的神经活动的测量。这种尖峰活动反映了给定大脑区域的输出，但许多区域以兴奋性或抑制性突触电位的形式接收输入，而不产生尖峰。这种输入活动是计算集成的一种重要形式，在细胞外记录中检测为局部场电位（LFP）的扰动。 LFP 的定量分析是在频域中进行的，提供了跨神经元同步活动的测量。洛格西蒂斯等人。 (2001) 表明 BOLD 可能反映一个区域以突触电位形式的输入，而不是以尖峰形式的输出。突触输入可以是兴奋性的或抑制性的，这两种形式都涉及可能改变 BOLD 的代谢需求，并使将 BOLD 解释为认知参与代理的模型变得复杂。人们对各种频段振荡的时间进程、兴奋性和抑制性突触电位，以及这些形式的活动和认知之间的关系（如 BOLD 所反映的）知之甚少。因此，有必要检查某些形式的神经活动、BOLD 与认知过程的参与之间的对应关系。例如，在某些情况下，负 BOLD 信号需要进行细致入微的解释。 fMRI 的减法性质最初表明，阴性 BOLD 仅反映了基线期间激活的增加。然而，许多研究结果表明，负 BOLD 代表了一种独特的现象。该提案的重点是检查负 BOLD 反映与认知相关的神经活动减少的证据。 BOLD 和 CBF 的校准 MR 测量将使用先前显示的任务来执行，以产生可靠的停用。这些流量和氧合的 MR 测量将用于确定相对 CMRO2 和氧提取，以全面评估 BOLD 的生理基础。将同时记录 EEC，并将多个频段的 EEC 功率与 MR 测量值进行比较。已经进行了大量工作来表征要使用的任务中的 EEC 变化，但很少有工作尝试将 EEC 与 MR 信号联系起来。这项工作将深入了解认知任务中的 MR 信号变化与通过表面和有限数量的患者硬膜下电极测量的 EEC 变化之间的关系。

项目成果

Dissociation between the activity of the right middle frontal gyrus and the middle temporal gyrus in processing semantic priming.

• DOI: 10.1371/journal.pone.0022368
• 发表时间: 2011
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Laufer I;Negishi M;Lacadie CM;Papademetris X;Constable RT
• 通讯作者: Constable RT

Modulating intrinsic connectivity: adjacent subregions within supplementary motor cortex, dorsolateral prefrontal cortex, and parietal cortex connect to separate functional networks during task and also connect during rest.

• DOI: 10.1371/journal.pone.0090672
• 发表时间: 2014
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Roth JK;Johnson MK;Tokoglu F;Murphy I;Constable RT
• 通讯作者: Constable RT

Sensory and cognitive mechanisms of change detection in the context of speech.

• DOI: 10.1007/s00429-007-0167-8
• 发表时间: 2008-02
• 期刊: BRAIN STRUCTURE & FUNCTION
• 影响因子: 3.1
• 作者: Laufer, Ilan;Negishi, Michiro;Rajeevan, Nallakandi;Lacadie, Cheryl M.;Constable, R. Todd
• 通讯作者: Constable, R. Todd

A graphics processing unit accelerated motion correction algorithm and modular system for real-time fMRI.

• DOI: 10.1007/s12021-013-9176-3
• 发表时间: 2013-07
• 期刊: NEUROINFORMATICS
• 影响因子: 3
• 作者: Scheinost, Dustin;Hampson, Michelle;Qiu, Maolin;Bhawnani, Jitendra;Constable, R. Todd;Papademetris, Xenophon
• 通讯作者: Papademetris, Xenophon

Comparator and non-comparator mechanisms of change detection in the context of speech--an ERP study.

• DOI: 10.1016/j.neuroimage.2008.09.010
• 发表时间: 2009-01-15
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Laufer I;Negishi M;Constable RT
• 通讯作者: Constable RT