Polianskiĭ V B, Alymkulov D E, Evtikhin D V, Sokolov E N
Zh Vyssh Nerv Deiat Im I P Pavlova. 2007 Sep-Oct;57(5):576-90.
Changes in activity of 83 neurons in the rabbit colliculus superior evoked by the replacement of eight color and eight achromatic stimuli in pairs were analyzed. It was found out that neurons displayed the early and late phasic responses (within 50-90 and 120-300 ms respectively, after the replacement) and long-term tonic response component, which depended on stimuli intensity. Analysis of phasic component revealed three neuronal groups. The first group (n=25, 30%) selected on the basis of the earliest component, was specialized to differentiate stimuli only by intensities. The perceptual spaces of these neurons reconstructed on the basis of spike discharge in the earliest response were two-dimensional. The second group of neurons (n=16, 19%) selected on the basis of the late phasic component demonstrated four-dimensional structure of perceptual space. Neurons of the third group (n=4, 5%) possessed a two-dimensional structure of perceptual space reconstructed by the analysis of the early component, whereas analysis of the late response revealed a four-dimensional structure. We suggest that information about differences between stimuli in color and intensity coming from cortical neurons is necessary for the reconstruction of four-dimensional space. The structure of perceptual spaces reconstructed on the basis of phasic responses of neurons in the colliculus superior was similar to the spaces of neurons in the primary visual cortex and lateral geniculate nucleus. The structure of perceptual space reconstructed on the basis of neuronal spikes was also similar to the space calculated from the N85 component of the visual evoked potential recorded under similar conditions. This finding confirms the general principle of vector coding in the visual system.
分析了成对替换八种颜色和八种非彩色刺激时，家兔上丘中83个神经元的活动变化。结果发现，神经元表现出早期和晚期相位反应（分别在替换后50 - 90毫秒和120 - 300毫秒内）以及长期的紧张性反应成分，后者取决于刺激强度。对相位成分的分析揭示了三个神经元组。第一组（n = 25，30%）基于最早的成分挑选出来，专门仅通过强度来区分刺激。根据最早反应中的脉冲放电重构的这些神经元的感知空间是二维的。基于晚期相位成分挑选出的第二组神经元（n = 16，19%）表现出感知空间的四维结构。第三组神经元（n = 4，5%）通过早期成分分析重构的感知空间具有二维结构，而晚期反应分析则揭示出四维结构。我们认为，来自皮层神经元的关于颜色和强度刺激差异的信息对于四维空间重构是必要的。基于上丘中神经元的相位反应重构的感知空间结构与初级视觉皮层和外侧膝状体中神经元空间相似。基于神经元脉冲重构的感知空间结构也与在类似条件下记录的视觉诱发电位的N85成分计算出的空间相似。这一发现证实了视觉系统中矢量编码的一般原则。
