Biederlack Julia, Castelo-Branco Miguel, Neuenschwander Sergio, Wheeler Diek W, Singer Wolf, Nikolić Danko
Mibeg-Institut for Media, Sachsenring 37-39, 50677 Cologne, Germany.
Neuron. 2006 Dec 21;52(6):1073-83. doi: 10.1016/j.neuron.2006.11.012.
In cat visual cortex, we investigated with parallel recordings from multiple units the neuronal correlates of perceived brightness. The perceived brightness of a center grating was changed by varying the orientation or the relative spatial phase of a surrounding grating. Brightness enhancement by orientation contrast is associated with an increase of discharge rates of responses to the center grating but not with changes in spike synchronization. In contrast, if brightness enhancement is induced by phase offset, discharge rates are unchanged but synchronization increases between neurons responding to the center grating. The changes in synchronization correlate well with changes in perceived brightness that were assessed in parallel in human subjects using the same stimuli. These results indicate that in cerebral cortex the modulation of synchronicity of responses is used as a mechanism complementary to rate changes to enhance the saliency of neuronal responses.
在猫的视觉皮层中，我们通过对多个神经元进行并行记录，研究了感知亮度的神经元相关性。通过改变周围光栅的方向或相对空间相位，改变了中心光栅的感知亮度。方向对比度引起的亮度增强与对中心光栅反应的放电率增加有关，但与尖峰同步性的变化无关。相比之下，如果亮度增强是由相位偏移引起的，放电率不变，但对中心光栅做出反应的神经元之间的同步性增加。同步性的变化与使用相同刺激在人类受试者中并行评估的感知亮度变化密切相关。这些结果表明，在大脑皮层中，反应同步性的调制被用作一种与速率变化互补的机制，以增强神经元反应的显著性。
