Stronger inference with direct manipulation of brain function.
Stronger inference with direct manipulation of brain function.
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通过直接操纵大脑功能进行更强的推理。
DOI：
10.1016/j.cortex.2008.12.008
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Feredoes,Eva
中科院分区：
文献类型：
--
作者：
Postle,BradleyR;Feredoes,Eva
在教育的早期阶段，我们都知道统计显着性不一定意味着功能显着性，相关性并不意味着因果关系。尽管有这些警告，但毫无疑问的是，认知神经科学已经通过功能神经影像的基本相关方法了解了大量有关行为的神经基础的知识。当仔细控制的神经影像学研究可以说明大脑区域的功能特性时尤其如此，而该大脑区域对特定行为方面的必要性已通过病变数据确定。然而，可能会出现两种不同的神经影像学研究（实际上，正如我们将在这里回顾的，对同一数据集的两种不同分析）产生相互不兼容的结果的情况，从而使实验旨在解决的结构功能映射的性质变得模糊。在这种情况下，以前瞻性方式局部改变大脑功能的能力可能特别有用。本评论中所讨论的认知方面是短期记忆和工作记忆测试所需的信息的短期保留（STR，又名“存储”或“维护”）。实施此结构的一种方法是改变不同试验中必须保留的项目数量。在对以这种方式操纵语言记忆负荷的研究进行回顾的推动下，我们对功能性磁共振成像 (fMRI) 期间（7 秒）延迟识别任务中保留 2 与 5 个字母的 24 名受试者样本的数据进行了两种不同的分析：空间归一化组平均 (SNGA) 分析；单受试者 (SS) 分析将每个受试者的数据视为个案（Feredoes 和 Postle，2007）。 SNGA 分析揭示了前额皮质 (PFC) 的左后额中回 (MFG) 中的一个区域，靠近布罗德曼区域 9 和 6 的边界，该区域对负载的操纵非常敏感，因此是言语信息 STR 的候选位点。（这也复制了之前也使用 SNGA 分析的研究结果（例如，Narayanan 等人，2005 年）。）SS 分析，相比之下，所产生的结果在不同受试者之间存在很大的地形差异，并且值得注意的是，不包括任何受试者的左后 MFG。相反，表现出负荷效应的区域最好概括为发生在大多数受试者的左后周外侧皮层中。这些结果促使我们解决一个明显的问题：哪些大脑区域被识别出来
At an early stage in our educations we have all learned that statistical significance need not imply functional significance, and, relatedly, that correlation does not imply causation. Despite these caveats, it is indisputable that cognitive neuroscience has learned a great deal about the neural bases of behaviour via the fundamentally correlative methods of functional neuroimaging. This is particularly true in cases when a carefully controlled neuroimaging study can illustrate functional properties of a brain region whose necessity for a particular aspect of behaviour has been established with lesion data. There can arise, however, situations in which two different neuroimaging studies (and indeed, as we will review here, two different analyses of the same data set) produce mutually incompatible results, thereby leaving ambiguous the nature of the structure-function mapping that the experiments were designed to address. This is a situation in which the ability to locally alter brain function in a prospective manner can be particularly useful.The aspect of cognition that is at issue in this commentary is the short-term retention (STR, aka “storage” or “maintenance”) of information that is required by tests of short-term and working memory. One way to operationalise this construct is to vary the number of items that must be retained on different trials. Prompted by a review of studies that manipulated verbal memory load in this way, we applied two different analyses to the data from a sample of 24 subjects retaining 2 vs. 5 letters in a (7 sec) delayed-recognition task during functional magnetic resonance imaging (fMRI): a spatially normalized group-average (SNGA) analysis; and singlesubject (SS) analyses that treated each subject’s data as an individual case (Feredoes and Postle, 2007). The SNGA analysis revealed a region in left posterior middle frontal gyrus (MFG) of the prefrontal cortex (PFC), near the border of Brodmann Areas 9 and 6, that was reliably sensitive to the manipulation of load, and, therefore, a candidate locus for the STR of verbal information.(This also replicated the findings of previous studies that had also used SNGA analyses (eg, Narayanan et al., 2005).) The SS analyses, in contrast, produced results that were topographically highly variable across subjects and, notably, did not include the left posterior MFG in any subject. Instead, the regions demonstrating load effects were best summarized as occurring in left posterior perisylvian cortex in the majority of subjects. These results prompted us to address the obvious question of which brain regions, those identified