Deen Ben, Saxe Rebecca, Bedny Marina
Massachusetts Institute of Technology.
J Cogn Neurosci. 2015 Aug;27(8):1633-47. doi: 10.1162/jocn_a_00807. Epub 2015 Mar 24.
In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.
在先天性失明中，枕叶皮质会对一系列非视觉输入产生反应，包括触觉、听觉和语言刺激。这些对刺激的功能反应变化是否伴随着与非视觉功能网络相互作用的改变？为了回答这个问题，我们引入了一种数据驱动的方法，在整个皮质中搜索不同组之间的功能连接差异。重复先前的研究，我们发现相对于蒙眼的视力正常参与者，先天性盲人的额枕功能连接增加。我们证明这种增强的连接延伸到枕叶皮质的大部分区域，但特定于额叶下部、背侧和内侧的一个区域子集。为了评估这些额叶区域的功能特征，我们使用了n-back工作记忆任务和句子理解任务。我们发现，在与枕叶皮质过度连接的前额叶区域中，一个左侧额叶下部区域对语言而非音乐有反应。相比之下，这些区域中的大多数对工作记忆负荷有反应，但对语言没有反应。这些结果表明，在失明状态下，枕叶皮质与工作记忆系统的相互作用更多，并对枕叶可塑性的功能和机制提出了新的问题。
