Macaque V2 neurons, but not V1 neurons, show choice-related activity
Macaque V2 neurons, but not V1 neurons, show choice-related activity
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DOI：
10.1523/jneurosci.2256-06.2006
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发表时间：
2006-09-13
影响因子：
5.3
通讯作者：
Cumming, Bruce G.
中科院分区：
文献类型：
--
作者：
Nienborg, Hendrikje;Cumming, Bruce G.
在猕猴的纹外皮质中，知觉选择和神经元反应之间的相关性已经被证明，通常被量化为选择概率(CPS)。这种相关性在早期的视觉皮质中并不明显，这表明CPS可能取决于神经元在视觉处理层级中的位置。然而，以前的研究没有比较在同等任务中具有类似精度的神经元。我们使用一个先前已经描述了关于中颞区(MT)的显著CP的任务来研究皮层层次在CP中的作用。我们测量了来自V1和V2的视差选择神经元的CP。刺激是一个动态的随机点立体图，呈现出近距离或远距离的差异，被不同数量的双目不相关的点所掩盖。两只猕猴报告了它们在强迫选择任务中是否感觉到周围环的前面或后面有一个圆形斑块。对于V2(n=69)，CP平均为0.56，这是早在V2时视觉区域第一次出现系统性CP。V1组(n=74)CP均值为0.51。在选择的一组神经元中，这种模式相似，因此任务中的统计精度与MT的平均统计精度相同(平均CP，V1为0.51，n=33；V2为0.58，n=54)。V1和V2之间的这种差异不能用眼球运动、刺激相对于感受野的大小或视差调节的差异来解释。相反，它似乎反映了纹状体和纹外皮质之间的功能差异(至少在视差处理方面)。
In the macaque extrastriate cortex, robust correlations between perceptual choice and neuronal response have been demonstrated, frequently quantified as choice probabilities (CPs). Such correlations are modest in early visual cortex, suggesting that CPs may depend on the position of a neuron in the hierarchy of visual processing. However, previous studies have not compared neurons with similar precision in equivalent tasks.We investigated the role of cortical hierarchy on CP using a task for which significant CPs have been described previously for middle temporal area (MT). We measured CPs in disparity-selective neurons from both V1 and V2. The stimulus was a dynamic random dot stereogram, presented with a near or a far disparity, masked by varying numbers of binocularly uncorrelated dots. Two macaque monkeys reported whether they perceived a circular patch in front or behind a surrounding annulus in a forced choice task.For V2(n = 69), CP was on average 0.56, the first demonstration of systematic CPs in a visual area as early as V2. In V1(n = 74), average CP was at chance level (0.51). The pattern was similar in a subgroup of neurons selected such that the statistical precision in the task was on average identical to that reported for MT(mean CP, 0.51 for V1, n = 33; 0.58 for V2, n = 54). This difference between V1 and V2 could not be explained by eye movements, stimulus size relative to the receptive field, or differences in disparity tuning. Rather, it seems to reflect a functional difference (at least in disparity processing) between striate and extrastriate cortex.