Abstract

The minimum discriminable target velocity was determined with and without reference lines in the visual field. At a short (0.125 sec) exposure duration, where velocity discrimination is determined primarily by the magnitude of initial photochemical events, the velocity threshold is not changed by the introduction of reference lines. At a long (16 sec) exposure duration, the presence of reference lines lowers the threshold velocity by 48%. The data are interpreted as supporting the hypothesis that movement is discriminated at slow speeds by observation of change of position.

© 1955 Optical Society of America

Velocity Discrimination and the Intensity-Time Relation

Robert H. Brown
J. Opt. Soc. Am. 45(3) 189-192 (1955)

Radial Localization of a Single Stimulus as a Function of Luminance and Duration of Exposure*

H. W. Leibowitz, Nancy A. Myers, and D. A. Grant
J. Opt. Soc. Am. 45(2) 76-78 (1955)

Critical Duration in Visual Brightness Discrimination for Retinal Areas of Various Sizes

William R. Biersdorf
J. Opt. Soc. Am. 45(11) 920-925 (1955)

Influence of Stimulus Luminance upon the Upper Speed Threshold for the Visual Discrimination of Movement

Robert H. Brown
J. Opt. Soc. Am. 48(2) 125-128 (1958)

Effects of Involuntary Eye Movements on Visual Acuity*

Ulker Tulunay Keesey
J. Opt. Soc. Am. 50(8) 769-774 (1960)