Adaptation to peripheral flicker

Abstract

With strict fixation, a flickering disk presented in the peripheral retina rapidly appeared to lose contrast and stop flickering, owing to adaptation. Subjects measured this adaptation by continually adjusting the flicker amplitude of a peripherally viewed disk to hold it just at threshold.

Results: (1) The contrast threshold for flicker increased logarithmically over time. (2) The slope of the temporal decay function increased with eccentricity (1-16 deg) and with decreasing disk size (8 deg-3.6 min arc). (3) M-scaling the stimulus size could abolish the dependence upon eccentricity for small disks, but not completely for large disks. (4) The temporal decay rate increased with flicker rate (3-15 Hz), as though each cycle of flicker elevated contrast threshold equally.