Spatial phase sensitivity for sinusoidal grating targets

Abstract Because the full specification of a sinusoidal grating target must include phase as well as amplitude, an experiment was performed to determine the phase sensitivity for sinusoidal gratings in central vision for normal human observers. Phase displacement thresholds for sinusoidal gratings ranging in spatial frequency from 3 to 25 cycles/degree are a linear function of spatial frequency (1° of phase angle per c/deg). The just-detectable lateral distances are constant and equal to those for a single line.