Feedback connections act on the early part of the responses in monkey visual cortex
Feedback connections act on the early part of the responses in monkey visual cortex
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DOI：
10.1152/jn.2001.85.1.134
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发表时间：
2001-01-01
影响因子：
2.5
通讯作者：
Bullier, J
中科院分区：
文献类型：
--
作者：
Hupé, JM;James, AC;Bullier, J
我们以前表明，MT的反馈连接在图形/地面分割中发挥作用。图形/背景编码已被描述在V1水平的神经元对视觉刺激的反应的后期部分，它已被建议，这些后期调制依赖于反馈连接。在目前的工作中，我们测试是否实际上需要时间将这些信息反馈到较低的订单领域。我们分析了169 V1，V2和V3神经元的细胞外反应，我们记录在两个麻醉猕猴。通过冷却使MT失活。我们研究了MT失活显著影响神经元反应的时间过程，以观察这些效应是否相对于反应的开始有所延迟。我们首先测量了MT对V1，V2和V3神经元的反馈影响的时间过程。对于反应降低的51个神经元中的大多数，从反应开始时就存在这种影响。在标准化后平均的响应中，响应的减少在响应的第一个10 ms箱中是显著的。一个类似的结果被发现为6个神经元的反应显着增加时，MT被灭活。然后我们研究了对闪光刺激（95个神经元）反应的时间过程。我们观察到15个显著下降的反应和14个显著增加。在这两个群体中，在响应的前10 ms内的影响是显着的。对于一些反应增加的神经元，当MT失活时，我们甚至观察到更短的潜伏期。我们测量了对闪光刺激的反应的潜伏期。我们发现，即使是最早反应的神经元也会在早期受到MT反馈的影响。对于闪光和移动刺激的反应也是如此。这些结果表明，反馈连接被招募非常早的视觉信息的处理。它进一步表明，反馈效应的存在或不存在不能从响应调制的时间过程中推断出来。
We previously showed that feedback connections from MT play a role in figure/ground segmentation. Figure/ground coding has been described at the V1 level in the late part of the neuronal responses to visual stimuli, and it has been suggested that these late modulations depend on feedback connections. In the present work we tested whether it actually takes time for this information to be fed back to lower order areas. We analyzed the extracellular responses of 169 V1, V2, and V3 neurons that we recorded in two anesthetized macaque monkeys. MT was inactivated by cooling. We studied the time course of the responses of the neurons that were significantly affected by the inactivation of MT to see whether the effects were delayed relative to the onset of the response. We first measured the time course of the feedback influences from MT on V1, V2, and V3 neurons tested with moving stimuli. For the large majority of the 51 neurons for which the response decreased, the effect was present from the beginning of the response. In the responses averaged after normalization, the decrease of response was significant in the first 10-ms bin of response. A similar result was found for six neurons for which the response significantly increased when MT was inactivated. We then looked at the time course of the responses to flashed stimuli (95 neurons). We observed 15 significant decreases of response and 14 significant increases. In both populations, the effects were significant within the first 10 ms of response. For some neurons with increased responses we even observed a shorter latency when MT was inactivated. We measured the latency of the response to the flashed stimuli. We found that even the earliest responding neurons were affected early by the feedback from MT. This was true for the response to flashed and to moving stimuli. These results show that feedback connections are recruited very early for the treatment of visual information. It further indicates that the presence or absence of feedback effects cannot be deduced from the time course of the response modulations.