Summation and inhibition in the frog's retina.

Action potentials from the frog's retina.

1) Measurements of electrical excitability of the eye after exposure to light (C-method)

the intensity of the stimulus. Later, Granit7)8) determined flicker fusion frequencies for similar four circular test spots together and for each of the spots alone and found spatial summation effects in the human retina. Furthermore, spatial summation in the human retina was studied by Motokawa9) with increases of electrical excitability by illumination as an index. He has shown that increases...

A. Modelling the Group 2 Ganglion Cell of the Frog's Retinat

Since Lettvin, Maturana, McCulloch, and Pitts l ' 2 published their measurements of signals in the optic fibers of the frog, considerable effort 3' 4 has been given to developing models that could account for the properties they found. Such models are of importance to engineers and neurophysiologists for two reasons. First, models provide clues on which to base advanced and versatile engineerin...

A study on the effects of constant polarizing current on the human electroretinogram and visual sensitivity.

Granit and Helme (1) found that the electroretinogram (ERG) of the darkadapted frog's eye was effected by a constant electric current running across the retina (polarizing current). They reported that both band d-waves of ERG were enhanced by the current flowing through the retina from the outside into the inside of the bulb (this direction of the current was called "inside cathode"), but they ...

What the Frog's Eye Tells the Frog's Brain * †

A. Behavior of a Frog A frog hunts on land by vision. He escapes enemies mainly by seeing them. His eyes do not move, as do ours, to follow prey, attend suspicious events, or search for things of interest. If his body changes its position with respect to gravity or the whole visual world is rotated about him, then he shows compensatory eye movements. These movements enter his hunting and evadin...