The optimal synapse for sparse, binary signals in the rod pathway.
The sparsity of photons at very low light levels necessitates a nonlinear synaptic transfer function between the rod photoreceptors and the rod-bipolar cells. We examine different ways to characterize the performance of the pathway: the error rate, two variants of the mutual information, and the signal-to-noise ratio. Simulation of the pathway shows that these approaches yield substantially different performance at very low light levels and that maximizing the signal-to-noise ratio yields the best performance when judged from simulated images. The results are compared to recent data.
Clark
Paul T
PT
Institute for Adaptive and Neural Computation, School of Informatics, Edinburgh, EH1 2QL, UK. s9905130@sms.ed.ac.uk
van Rossum
Mark C W
MC
D000818:Animals; D015350:Contrast Sensitivity / Q000502:physiology / Q000528:radiation effects; D003623:Dark Adaptation / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D008027:Light; D008959:Models, Neurological; D016571:Neural Networks, Computer; D010775:Photic Stimulation; D017785:Photons; D051245:Retinal Bipolar Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology* / Q000528:radiation effects; D012684:Sensory Thresholds / Q000502:physiology / Q000528:radiation effects; D013569:Synapses / Q000502:physiology / Q000528:radiation effects; D009435:Synaptic Transmission / Q000502:physiology* / Q000528:radiation effects; D014785:Vision, Ocular / Q000502:physiology* / Q000528:radiation effects; D014795:Visual Pathways / Q000502:physiology*