Directionally selective visual units recorded in optic tectum of the goldfish
Article
Wartzok, D, Marks, WB. (1973). Directionally selective visual units recorded in optic tectum of the goldfish
. JOURNAL OF NEUROPHYSIOLOGY, 36(4), 588-604. 10.1152/jn.1973.36.4.588
Wartzok, D, Marks, WB. (1973). Directionally selective visual units recorded in optic tectum of the goldfish
. JOURNAL OF NEUROPHYSIOLOGY, 36(4), 588-604. 10.1152/jn.1973.36.4.588
This study has shown a definite similarity in the mechanism of directionally selective units in the goldfish and in animals at a great taxonomic distance from the goldfish: the rabbit and the ground squirrel. In all these animals the directional property has been shown to reside in subunits within the receptive field. Also, inhibition to movement in the null direction plays the primary role in establishing directional selectivity in these animals. Both the 2° diameter of the subunits and the 4° average diameter of the receptive fields in the goldfish are larger than the respective measurement in the mammals. The computer mapping technique employed has shown that each subunit of the dominant on type of directionally selective unit must have the same acceptance angle and preferred direction as the entire unit. The acceptance angle averaged 157° and is comparable with that of the rabbit, but larger than that of the ground squirrel. The asymmetry in the distribution of preferred directions, with two thirds nasal or nasal dorsal, exceeds that in other animals. There was no correlation between the preferred direction and the location in the visual field. Correlations between the single unit data of this study and reported observations on goldfish eye movements indicate that the directionally selective units are employed in the visual tracking behavior. The assymetry of the direction of tracking agrees with the asymmetry in preferred directions. Also the minimum and maximum of the tested dynamic range of eye tracking corresponds to the minimum and optimal speeds, respectively, of the directional units.
