Stimulus similarity modulates competitive interactions in human visual cortex
Stimulus similarity modulates competitive interactions in human visual cortex
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DOI：
10.1167/7.2.19
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发表时间：
2007-01-01
影响因子：
1.8
通讯作者：
Kastner, Sabine
中科院分区：
文献类型：
--
作者：
Beck, Diane M.;Kastner, Sabine
当多个视觉刺激同时出现在神经元的感受野中时，它们往往通过相互抑制它们的视觉诱发反应而相互作用，这表明同时出现在视野中的多个刺激竞争神经表征。以前的研究表明，这些抑制性交互作用可能会受到自上而下的影响，如空间定向注意，以及自下而上的视觉显著因素。使用功能磁共振成像，我们询问竞争性交互是否也可能受到其他自下而上因素的调节，并测试刺激相似性的影响。具体地说，我们发现，通过比较同时(潜在竞争)和顺序(非竞争)呈现引起的活动，V4区的抑制性交互作用在四个项目相同时比四个项目在颜色和方向上不同时减少。这样的结果与预测一致，即竞争更有可能发生在群体之间，而不是群体内部。
When multiple visual stimuli are simultaneously presented in a neuron's receptive field, they often interact with each other by mutually suppressing their visually evoked responses, suggesting that multiple stimuli present at the same time in the visual field compete for neural representation. Previous research has shown that these suppressive interactions can be biased by top-down influences such as spatially directed attention, as well as by the bottom-up factor of visual salience. Using fMRI, we asked whether competitive interactions might also be modulated by other bottom-up factors and tested the effects of stimulus similarity. Specifically, we found that suppressive interactions in area V4, measured by comparing activity evoked by simultaneous ( potentially competing) and sequential (noncompeting) presentations, were reduced when four items were identical relative to when the four items differed in color and orientation. Such a result is consistent with the prediction that competition is more likely to occur between groups than within a group.