Contrast detection in frog's retina.
D000818:Animals; D001001:Anura / Q000502:physiology*; D004596:Electroretinography; D005133:Eye Movements; D008962:Models, Theoretical; D009474:Neurons / Q000502:physiology; D010786:Photoreceptor Cells / Q000502:physiology; D012160:Retina / Q000502:physiology*