視網膜對動態視覺的預測資訊的編碼

Encoding the Predictive Information of Visual Motion in the Retina

陳冠豪(Kuan-Hao Chen)

指導教授 ： 焦傳金 ； 陳志強

國立清華大學/生命科學院/分子醫學研究所/碩士(2021年)

摘要

為了及時反應，動物一定要透過預測來克服神經處理的延遲。過去的 研究已經證明視網膜的細胞能夠預測預測物體移動。為了去了解這樣的特 性，我們給視網膜看隨機移動的物體，並用多電極去量測。物體移動的軌 跡是由一種隨機過程產生，並且會由低通濾波過濾，而產生不同頻率的軌 跡。我們接著計算神經細胞輸出與軌跡的相互資訊。並且我們發現有兩種 細胞—可預測性與不可預測的細胞。可預測性與軌跡頻率也有關係。最後 我們發展一種模型，這個模型包括前饋與反饋的抑制，並且這個抑制是來 自於水平細胞。這種模型可以解釋為什麼視網膜能預測物體移動。

關鍵字

視網膜 ； 預測 ； 模型 ； 隨機運動 ； 互信息 ； 負回饋

並列摘要

To produce timely responses, animals must conquer delays from visual pro­ cessing pathway by predicting motion. Previous studies [1] revealed that predic­ tive information of motion is encoded in spiking activities of retinal ganglion cells (RGCs) early in the visual pathway. In order to study the predictive properties of a retina in a more systematic manner, stimuli in the form of a stochastic moving bar are used in experiments with retinas from bull frogs in a multi­electrode sys­ tem. We then investigated the predictive properties of single RGC by calculating the time shifted (δt) mutual information (MI(x,r;δt)) between spiking output (r(t)) from a single RGC and the bar trajectories (x(t)). Two kinds of cells are charac­ terized: predictive RGCs and non­predictive RGCs. In order to further understand the mechanism of prediction, we develop a negative group delay model which is based on Voss＇s [2] paper to generate anticipatory responses. We extend our model to spatial version and use the same stimulation condition as we use in experiments. The model indicates that delayed negative feedback is crucial for producing antic­ ipation dynamics. Besides, we also show feedforward inhibition can also generate similar prediction dynamics. Besides, our feedback and feedforward model can also predict constant velocity moving bar [3]. After adding LPOU noises into con­ stant velocity moving bar, our model even predicts better than Berry gain control model [3] which explains anticipation of constant velocity moving bar. To sum up, our feedback and feedforward model can anticipate both stochastic and constant velocity moving bar with and without noises.

並列關鍵字

Retina ； Prediction ； Model ； Stochastic motion ； Mutual Information ； Negative feedback

參考文獻

[1] S. E. Palmer, O. Marre, M. J. Berry, and W. Bialek, “Predictive information in a sensory population,” Proceedings of the National Academy of Sciences, vol. 112, no. 22, pp. 6908– 6913, 2015.

[2] H. U. Voss, “Signal prediction by anticipatory relaxation dynamics,” Phys. Rev. E, vol. 93, p. 030201, Mar 2016.

[3] M. J. Berry, I. H. Brivanlou, T. A. Jordan, and M. Meister, “Anticipation of moving stimuli by the retina,” Nature, vol. 398, no. 6725, pp. 334–338, 1999.

[4] R. H. Kramer and C. M. Davenport, “Lateral inhibition in the vertebrate retina: The case of the missing neurotransmitter,” PLOS Biology, vol. 13, pp. 1–8, 12 2015.

[5] H. M. Schreyer, Nonlinearities in bipolar cells and their role for encoding visual signals. PhD thesis, Georg­August University School of Science, 5 2018.