Anticipation and Negative Group Delay in a Retina

Po Yu Chou¹, Chikeung Chan^2*

¹Department of Physics, National Central University, Chungli, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:Chikeung Chan, email:ckchan@gate.sinica.edu.tw

The mechanism of negative group delay (NGD) is used to understand the anticipative capability of a retina. Experiments with retinas from bull frogs are performed to compare with the predictions of the NGD model. In particulars, whole field stochastic stimulation with various time correlations are used to probe anticipative responses from the retina. We find that the NGD model can reproduce essential features of experimental observations characterized by the cross correlations between the simulation and the retinal responses. The main finding is that the prediction horizon of a retina depends on the correlation time of the stimulation as predicted by the NGD model. Experiments with dark and bright Gaussian light pulses further support the NGD mechanism; but only for the dark pulses indicating that the NGD effect of a retina might originate from its OFF response. Our finding suggests that anticipation is the result of a system is using time delayed negative feedback to detect its changing environment adaptively.

Keywords: anticipation, negative group delay, retina, prediction