36
JERALD J. BERNSTEIN
Fig. 5. Projection of the left visual field onto the right optic tectum of the
goldfish. The arrows are midline and point rostrally. Upper right: dorsal tectal surface showing rows of numbered electrode positions. Lower: left visual field with
optimal stimulus positions corresponding to appropriate electrode positions in upper
right of figure. The chart covers 100' from the center of the field. Upper left: map
of medians and parallels calculated for visual field on the optic tectum. After Jacobson and Gaze ( 1964).
response surround: One type of unit responded only to the onset of light;
a second unit responded to the onset of light but also induced an inhibitory surround and discharged in response to changes in general bnckground illumination. The layers of the tectum will be A-F, as designated
by Jacobson and Gaze (1964). In the most superficial fiber layer ( A ) ,
stratum opticum of the units of Ariens Kappers et u2. (1960) responded
with on and on-off responses with on-off units predominating. There was