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首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >The function of bursts of spikes during visual fixation in the awake primate lateral geniculate nucleus and primary visual cortex
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The function of bursts of spikes during visual fixation in the awake primate lateral geniculate nucleus and primary visual cortex

机译：在清醒的灵长类灵长类外侧膝状体核和初级视皮层的视觉固定过程中，尖峰爆发的功能

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摘要

When images are stabilized on the retina, visual perception fades. During voluntary visual fixation, however, constantly occurring small eye movements, including microsaccades, prevent this fading. We previously showed that microsaccades generated bursty firing in the primary visual cortex (area V-1) in the presence of stationary stimuli. Here we examine the neural activity generated by microsaccades in the lateral geniculate nucleus (LGN), and in the area V-1 of the awake monkey, for various functionally relevant stimulus parameters. During visual fixation, microsaccades drove LGN neurons by moving their receptive fields across a stationary stimulus, offering a likely explanation of how microsaccades block fading during normal fixation. Bursts of spikes in the LGN and area V-1 were associated more closely than lone spikes with preceding microsaccades, suggesting that bursts are more reliable than are lone spikes as neural signals for visibility. In area V-1, microsaccade-generated activity, and the number of spikes per burst, was maximal when the bar stimulus centered over a receptive field matched the cell's optimal orientation. This suggested burst size as a neural code for stimuli optimality (and not solely stimuli visibility). As expected, burst size did not vary with stimulus orientation in the LGN. To address the effectiveness of microsaccades in generating neural activity, we compared activity correlated with microsaccades to activity correlated with flashing bars. Onset responses to flashes were about 7 times larger than the responses to the same stimulus moved across the cells' receptive fields by microsaccades, perhaps because of the relative abruptness of flashes.
机译：当图像稳定在视网膜上时，视觉感知就会减弱。但是，在自愿进行目视注视期间，不断发生的微小眼动（包括微扫视）可防止这种褪色。我们以前的研究表明，在存在固定刺激的情况下，微扫视在初级视觉皮层（V-1区）中产生了突发性放电。在这里，我们检查了由微扫视在外侧膝状核（LGN）和清醒猴子的V-1区域中产生的神经活动，以获取各种功能相关的刺激参数。在视觉固定过程中，微扫视通过在固定刺激上移动其感受野来驱动LGN神经元，这可能解释了微扫视在正常固视过程中如何阻止衰落。 LGN和V-1区域中的尖峰爆发与单独的尖峰与先前的微扫视联系更紧密，这表明突发比单独的尖峰作为可视性神经信号更可靠。在V-1区域，当条形刺激集中在感受野上并与细胞的最佳方向匹配时，微扫视产生的活性和每次爆发的尖峰数最大。这建议将突发大小作为刺激最优性的神经代码（而不仅仅是刺激可见性）。不出所料，LGN中的爆发大小不会随刺激方向而变化。为了解决微扫视在产生神经活动中的有效性，我们将与微扫视相关的活动与与闪烁条相关的活动进行了比较。对闪光的发作反应大约是对相同刺激通过微扫视穿过细胞感受野的反应的7倍，这可能是因为闪光的相对突然性。

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