Abstract
Receptive fields of single units in the carp's retina were explored with a small spot of white and monochromatic lights. Well-isolated single spike discharge 100-200 μV in amplitude was recorded with 5M NaCl-filled micropipettes about 1 μ in tip diameter.
1. The dimension of the receptive field in the dark-adapted retina was as large as 3mm. in radius.
2. When the response was ‘off’ at the center of the receptive field, it was ‘on’ at the periphery, and ‘on-off’ in the intermediary zone.
3. With white light three types of response pattern, on ' center units, ‘off’ center units and ‘on-off’ center units were distinguished.
4. The type of response pattern was different according to the wavelength of the light used. For example, an ‘off’ center unit as determined with white light was also an ‘off’ center unit when searched with red light, but an ‘on-off’ center unit when explored with blue-green light.
5. In some elements the type of response was fixed throughout the receptive field and independent of the wave-lengths.
