...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Computational Neuroscience >Attentional modulation of firing rate and synchrony in a model cortical network
【24h】

Attentional modulation of firing rate and synchrony in a model cortical network

机译：模型皮质网络中对射速和同步性的注意调制

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The response of a neuron in the visual cortex to stimuli of different contrast placed in its receptive field is commonly characterized using the contrast response curve. When attention is directed into the receptive field of a V4 neuron, its contrast response curve is shifted to lower contrast values (Reynolds et al., 2000). The neuron will thus be able to respond to weaker stimuli than it responded to without attention. Attention also increases the coherence between neurons responding to the same stimulus (Fries et al., 2001). We studied how the firing rate and synchrony of a densely interconnected cortical network varied with contrast and how they were modulated by attention. The changes in contrast and attention were modeled as changes in driving current to the network neurons. We found that an increased driving current to the excitatory neurons increased the overall firing rate of the network, whereas variation of the driving current to inhibitory neurons modulated the synchrony of the network. We explain the synchrony modulation in terms of a locking phenomenon during which the ratio of excitatory to inhibitory firing rates is approximately constant for a range of driving current values. We explored the hypothesis that contrast is represented primarily as a drive to the excitatory neurons, whereas attention corresponds to a reduction in driving current to the inhibitory neurons. Using this hypothesis, the model reproduces the following experimental observations: (1) the firing rate of the excitatory neurons increases with contrast; (2) for high contrast stimuli, the firing rate saturates and the network synchronizes; (3) attention shifts the contrast response curve to lower contrast values; (4) attention leads to stronger synchronization that starts at a lower value of the contrast compared with the attend-away condition. In addition, it predicts that attention increases the delay between the inhibitory and excitatory synchronous volleys produced by the network, allowing the stimulus to recruit more downstream neurons.
机译：通常使用对比度响应曲线来表征视觉皮层中神经元对放置在其感受野中的不同对比度的刺激的响应。当注意力集中在V4神经元的感受野上时，其对比反应曲线就会移至较低的对比值（Reynolds等，2000）。因此，神经元将能够对较弱的刺激做出反应，而不是无意识地对其做出反应。注意还增加了对相同刺激做出反应的神经元之间的连贯性（Fries等，2001）。我们研究了密集互连的皮层网络的发射率和同步度如何随对比度变化以及如何通过注意力进行调制。对比度和注意力的变化被建模为网络神经元驱动电流的变化。我们发现，增加到兴奋性神经元的驱动电流会增加网络的总体放电速度，而到抑制性神经元的驱动电流的变化会调制网络的同步性。我们根据锁定现象来解释同步调制，在锁定现象中，对于一系列驱动电流值，激发与抑制点火速率之比大致恒定。我们探讨了一个假设，即对比度主要表示为对兴奋性神经元的驱动，而注意力对应于对抑制性神经元的驱动电流的减少。使用该假设，该模型再现了以下实验观察结果：（1）兴奋性神经元的放电速率随对比度增加； （2）对于高对比度刺激，激发速率饱和并且网络同步； （3）注意将对比度响应曲线移至较低的对比度值； （4）注意力会导致更强的同步性，与旁观者情况相比，同步性始于对比度较低的值。此外，它预测注意力会增加网络产生的抑制性和兴奋性同步截击之间的延迟，从而使刺激物募集更多下游神经元。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号