Temporal modulation of spatial contrast vision in pigeons (Columba livia).

Spatiotemporal contrast sensitivity (CS) functions were obtained from four White Carneaux pigeons. The spatial frequency for each session was selected randomly from a group of five spatial frequencies ranging from 0.42 to 1.26 c/deg. Within the session, the temporal frequency varied from 1 to 32 Hz. When plotted as a function of spatial frequency, the CS functions peaked in the range 0.7-1.0 c/deg. When compared to data that had been collected at 0 Hz temporal modulation, the temporally modulated spatial CS functions showed reduced CS, especially at the higher spatial frequencies, and reduced peak spatial frequency. When plotted as a function of temporal frequency, the CS functions were flat up to 8-16 Hz. Above 16 Hz, the curves showed a sharp roll off. When plotted as a three-dimensional, spatiotemporal CS surface, the data had a number of characteristics in common with the three-dimensional spatiotemporal model of CS proposed by Burbeck and Kelly (J. Opt. Soc. Am. 70 (1980) 1121).