Arieli A, Sterkin A, Grinvald A, Aertsen A
Department of Neurobiology, Weizmann Institute of Science, Post Office Box 26, Rehovot 76100, Israel.
Science. 1996 Sep 27;273(5283):1868-71. doi: 10.1126/science.273.5283.1868.
Evoked activity in the mammalian cortex and the resulting behavioral responses exhibit a large variability to repeated presentations of the same stimulus. This study examined whether the variability can be attributed to ongoing activity. Ongoing and evoked spatiotemporal activity patterns in the cat visual cortex were measured with real-time optical imaging; local field potentials and discharges of single neurons were recorded simultaneously, by electrophysiological techniques. The evoked activity appeared deterministic, and the variability resulted from the dynamics of ongoing activity, presumably reflecting the instantaneous state of cortical networks. In spite of the large variability, evoked responses in single trials could be predicted by linear summation of the deterministic response and the preceding ongoing activity. Ongoing activity must play an important role in cortical function and cannot be ignored in exploration of cognitive processes.
哺乳动物皮层中的诱发活动以及由此产生的行为反应，对于相同刺激的重复呈现表现出很大的变异性。本研究考察了这种变异性是否可归因于持续活动。通过实时光学成像测量了猫视觉皮层中的持续和诱发的时空活动模式；同时采用电生理技术记录了局部场电位和单个神经元的放电情况。诱发活动似乎是确定性的，变异性源于持续活动的动态变化，大概反映了皮层网络的瞬时状态。尽管存在很大的变异性，但单次试验中的诱发反应可以通过确定性反应与先前持续活动的线性叠加来预测。持续活动必定在皮层功能中发挥重要作用，在认知过程的探索中不能被忽视。
