Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.
Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.
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DOI：
10.1371/journal.pone.0027204
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Valero-Cabre A
中科院分区：
文献类型：
--
作者：
Fried PJ;Elkin-Frankston S;Rushmore RJ;Hilgetag CC;Valero-Cabre A
光幻视通常由经颅磁刺激（TMS）诱发，以研究人类视觉大脑的功能组织，连接和兴奋性。多年来，光幻视仅在刺激枕叶皮层的早期视觉区（V1-V3）和少数专门的视觉区（V4，V5/MT+）中被记录。最近，有报道称，在将TMS应用于后顶叶皮层的一个区域后，出现了光幻视，该区域参与了视觉空间处理的自上而下的调制。在本研究中，我们系统的特点，顶叶光幻视，以确定它们是直接产生的本地机制或出现通过间接激活其他视觉领域。使用内部开发的技术来记录光幻视的主观特征，我们发现，与枕骨相比，顶叶光幻视的大小、形状、位置或参照系没有系统性差异。在第二个实验中，离散失活1赫兹重复TMS产生了双重解离：光幻视阈值增加在失活的网站，而不产生相应的变化，在非失活的位置。总的来说，顶叶和枕叶光幻视的共性，以及我们独立调节其兴奋性阈值的能力，使我们得出结论，它们共享一个共同的神经基础，与任何一个受刺激的区域分开。
Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS) to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1–V3) and a handful of specialized visual regions (V4, V5/MT+) in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.
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影响因子：
9.9
作者：
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通讯作者：
Ramadan, NM
影响因子：
2.5
作者：
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作者：
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作者：
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DOI：
10.1073/pnas.88.5.1621
发表时间：
1991-03-01
影响因子：
11.1
作者：
HAXBY, JV;GRADY, CL;RAPOPORT, SI
通讯作者：
RAPOPORT, SI