Functional MRI evidence for a role of frontal and inferior temporal cortex in amodal components of priming
Functional MRI evidence for a role of frontal and inferior temporal cortex in amodal components of priming
复制标题
DOI：
10.1093/brain/123.3.620
复制
发表时间：
2000-03-01
期刊：
影响因子：
14.5
通讯作者：
Rosen, BR
中科院分区：
文献类型：
--
作者：
Buckner, RL;Koutstaal, W;Rosen, BR
一系列神经成像和行为研究描述了单词生成过程中与重复启动相关的人类大脑活动变化。重复启动在行为学上表现为对重复项目的反应潜伏期的减少，并且在视觉和听觉提示的单词生成任务中均被发现。使用全脑功能MRI的脑成像确定了这些效应的神经相关性。视觉提示下的重复单词生成与左额叶皮层沿着额下回和颞下区的解剖学选择性活动减少相关，在较小程度上，在特定的早期视觉区域，这些减少在新项目出现时被逆转，表明它们是项目特异性的。重复的单词生成响应听觉线索也表现出解剖学上的选择性活动减少左额叶和颞下区，表明这些活动减少不依赖于知觉方式的线索。听觉皮层表现出最小的重复相关的减少。左额叶区域内的活动，减少视觉和听觉线索的项目重复的函数表明，这些减少可能是基础的非模态重复启动效应存在于处理阶段，涉及词汇/语义搜索和访问。令人惊讶的发现，活动减少下颞叶皮层可以链接到重复的视觉或听觉线索进一步表明，这些地区可能是调制在一个自上而下的方式在重复启动，独立于（或平行于）刺激驱动的感知过程。总的来说，数据收敛于词汇/语义启动的神经相关。非模态的词汇/语义过程，这可能是最初触发的特定模态的线索，进行通过额叶和后部的大脑区域之间的相互作用，这些相互依存的区域显示活动减少，与促进任务的性能时，项目被重复。
Changes in human brain activity associated with repetition priming during word generation were characterized across a series of neuroimaging and behavioural studies. Repetition priming was consistently observed behaviourally as a decrease in response latency for repeated items, and was found for both visually and aurally cued word-generation tasks, Brain imaging using whole-brain functional MRI identified neural correlates of these effects, The principal effect of priming was to reduce neural activity within regions that were already being used to perform the word-generation tasks. Repeated word generation in response to visual cues was correlated with anatomically selective reductions in activity within the left frontal cortex along the inferior frontal gyrus and inferior temporal regions and, to a lesser degree, in specific earlier visual regions, These reductions were reversed when new items were presented, indicating that they were item-specific. Repeated word generation in response to aural cues also showed anatomically selective activity reductions within the left frontal and inferior temporal regions, indicating that these activity reductions were not dependent on the perceptual modality of the cue. The auditory cortex showed minimal repetition-related reductions. The presence of activity within left frontal regions that decreases as a function of item repetition for both visual and auditory cues suggests that these reductions may underlie an amodal repetition-priming effect existing at processing stages involving lexical/semantic search and access. The surprising finding that activity reductions in the inferior temporal cortex can be linked to repetition of either visual or auditory cues further suggests that these regions may be modulated in a top-down fashion during repetition priming, independent of (or in parallel with) stimulus-driven perceptual processes, Taken collectively, the data converge on a neural correlate of lexical/semantic priming. Amodal lexical/semantic processes, which may be triggered initially by modality-specific cues, proceed via an interaction between frontal and posterior brain regions, These interdependent regions show activity reductions that correlate with facilitated task performance when items are repeated.