Left parietal cortex is modulated by amount of recollected verbal information.
Left parietal cortex is modulated by amount of recollected verbal information.
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DOI：
10.1097/wnr.0b013e3283306798
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发表时间：
2009-09-23
期刊：
影响因子：
1.7
通讯作者：
Rugg MD
中科院分区：
文献类型：
--
作者：
Vilberg KL;Rugg MD
在之前的两个实验中，我们报道了左下后顶叶皮层的活动与所收集的信息量呈协变关系。鉴于这两项研究中的实验材料完全是图画，所以问题是这些发现是否可以推广到其他类别的回忆内容。正如我们所讨论的，如果左下顶叶皮层支持以非模态方式再现所回忆的内容，那么当使用非图像材料时，该区域的活动也应该受到所回忆的数量的调节。目前的研究解决了左下后顶叶皮层是否对口头信息而不是图片信息的记忆量敏感的问题。在研究中，参与者看到了一系列单词对，在每种情况下都会生成一个包含这两个单词的句子。在测试中，新旧单个单词的混合出现在修改后的记住/知道任务中。如果参与者能够回忆起测试项目及其所研究的配对，则他们会做出一个反应（R2）；如果他们可以回忆起研究片段中的一些信息，但不能回忆起配对，则会做出另一种反应（R1）；如果测试项目被判断为在没有任何研究细节的记忆的情况下进行过研究，则会做出第三种反应（K）；或者第四种反应，新反应。我们假设对旧项目给予 R2 反应的试验平均比对旧项目给予 R1 反应时回忆更多的研究信息。因此，我们在操作上将“回收量”定义为这两种试验类型之间的对比（即 R2 命中 > R1 命中）。使用小体积校正程序，我们在相同的左下后顶叶区域内识别出一个簇，在我们之前的研究中使用相同的测试程序被识别为数量敏感。因此，我们之前的研究结果推广到非图像刺激材料，并支持左下后顶叶皮层在记忆信息的维持或表示中发挥一般作用的提议。
In two prior experiments we reported that activity in the left inferior posterior parietal cortex covaried with amount of information recollected. Given that the experimental materials in these two studies were exclusively pictorial, the question arises whether the findings generalize to other classes of recollected content. If, as we have argued, the left inferior parietal cortex supports the representation of recollected content in an amodal manner, then activity in this region should also be modulated by amount recollected when non-pictorial materials are employed. The current study addressed the question whether left inferior posterior parietal cortex is sensitive to amount of information recollected for verbal rather than pictorial information. At study, participants saw a series of word pairs, in each case generating a sentence that incorporated both words. At test, a mixture of old and new individual words were presented in a modified remember/know task. Participants made one response (R2) if they could recollect the test item and its studied pairmate, another response (R1) if they could recollect some information from the study episode but not the pairmate, a third response (K) if the test item was judged to have been studied in the absence of any recollection of study details, or a fourth, New, response. We assumed that trials where old items were given an R2 response were on average associated with recollection of more study information than when old items were given an R1 response. Thus, we operationally defined ‘amount recollected’ as the contrast between these two trial types (i.e., R2 hits > R1 hits). Using a small volume correction procedure, we identified a cluster within the same left inferior posterior parietal region identified as amount-sensitive in our prior study using the same test procedure. Thus, our prior findings generalize to non-pictorial stimulus materials and support the proposal that left inferior posterior parietal cortex plays a generic role in the maintenance or representation of recollected information.