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首页> 外文期刊>The European Journal of Neuroscience >Topography of attention in the primary visual cortex.
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Topography of attention in the primary visual cortex.

机译：在主要视觉皮层中注意的地形。

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Previous research suggests that feedback circuits mediate the effect of attention to the primary visual cortex (V1). This inference is mainly based on temporal information of the responses, where late modulation is associated with feedback signals. However, temporal data alone are inconclusive because the anatomical hierarchy between cortical areas differs significantly from the temporal sequence of activation. In the current work, we relied on recent physiological and computational models of V1 network architecture, which have shown that the thalamic feedforward, local horizontal and feedback contribution are reflected in the spatial spread of responses. We used multifocal functional localizer and quantitative analysis in functional magnetic resonance imaging to determine the spatial scales of attention and sensory responses. Representations of 60 visual field regions in V1 were functionally localized and four of these regions were targets in a subsequent attention experiment, where human volunteers fixated centrally and performed a visual discrimination task at the attended location. Attention enhanced the peak amplitudes significantly more in the lower than in the upper visual field. This enhancement by attention spread with a 2.4 times larger radius (approximately 10 mm, assuming an average magnification factor) compared with the unattended response. The corresponding target region of interest was on average 20% stronger than that caused by the afferent sensory stimulation alone. This modulation could not be attributed to eye movements. Given the contemporary view of primate V1 connections, the activation spread along the cortex provides further evidence that the signal enhancement by spatial attention is dependent on feedback circuits.
机译：先前的研究表明，反馈电路会介导对初级视觉皮层（V1）的注意力。该推断主要基于响应的时间信息，其中后期调制与反馈信号相关联。但是，单独的时间数据尚无定论，因为皮层区域之间的解剖层次与激活的时间顺序明显不同。在当前的工作中，我们依赖于V1网络体系结构的最新生理和计算模型，这些模型表明，丘脑前馈，局部水平和反馈贡献反映在响应的空间分布中。我们在功能磁共振成像中使用了多焦点功能定位器和定量分析来确定注意力和感觉反应的空间尺度。 V1中60个视野区域的表示在功能上进行了定位，其中四个区域是随后的注意力实验的目标，在该实验中，人类志愿者集中固定并在参与人员的位置执行了视觉识别任务。注意，在下部视野中，峰值幅度明显大于在上部视野中。与无人值守的响应相比，这种注意力的增强以2.4倍的半径传播（大约10毫米，假设平均放大倍数）。相应的目标目标区域平均比单独的传入感觉刺激引起的目标区域强20％。这种调制不能归因于眼球运动。鉴于灵长类动物V1连接的当代观点，沿皮层的激活扩展提供了进一步的证据，表明空间关注引起的信号增强取决于反馈电路。

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