Sawtooth contrast sensitivity: Decrements have the edge

Mirror-image sawtooth waveforms (rapid-on and rapid-off) were used to test for differences in sensitivity to incremental and decremental stimuli. Temporal contrast sensitivity functions were measured for rapid-on and rapid-off sawtooths and for sine wave stimuli (for 2-26 Hz, mean retinal illuminance of 500 td, circular target of 1.8 deg, foveal). Rapid-off sawtooths yielded higher sensitivity than rapid-on sawtooths at low and middle frequencies. This advantage for detection of decremental lights was confirmed in an experiment in which contrast sensitivity was determined for the sum of a rapid-on and a rapid-off waveform added over the full range of phase angles. Our data, based on periodic rather than pulsed stimuli, broaden and strengthen the evidence that the visual system is more sensitive to decrements than to increments in light level.

[1]  W. Stiles,et al.  Interactions among chromatic mechanisms as inferred from positive and negative increment thresholds. , 1964, Vision research.

[2]  John Krauskopf,et al.  Discrimination and detection of changes in luminance , 1980, Vision Research.

[3]  C. Rashbass.  The visibility of transient changes of luminance , 1970, The Journal of physiology.

[4]  V C Smith,et al.  Temporal modulation sensitivity and pulse-detection thresholds for chromatic and luminance perturbations. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[5]  V C Smith,et al.  Phase-dependent sensitivity to heterochromatic flicker. , 1986, Journal of the Optical Society of America. A, Optics and image science.

[6]  A. Short,et al.  Decremental and incremental visual thresholds , 1966, The Journal of physiology.

[7]  D H Kelly,et al.  Theory of flicker and transient responses. III. An essential nonlinearity. , 1978, Journal of the Optical Society of America.

[8]  J. Levinson,et al.  Fusion of Complex Flicker II , 1960, Science.

[9]  M. Sanders.  Handbook of Sensory Physiology , 1975 .

[10]  D. H. Kelly.  Visual response to time-dependent stimuli. I. Amplitude sensitivity measurements. , 1961, Journal of the Optical Society of America.

[11]  Louis W. Gellermann.  Chance Orders of Alternating Stimuli in Visual Discrimination Experiments , 1933 .

[12]  S. W. Kuffler.  Discharge patterns and functional organization of mammalian retina. , 1953, Journal of neurophysiology.

[13]  J. Bergen,et al.  Prediction of flicker sensitivities from temporal three-pulse data , 1985, Vision Research.

[14]  T. Cohn,et al.  Spatial summation of foveal increments and decrements , 1975, Vision Research.

[15]  H. D. L. Dzn.  Research into the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. I. Attenuation characteristics with white and colored light. , 1958 .

[16]  R. Jung.  Visual Perception and Neurophysiology , 1973 .

[17]  L. Kaufman,et al.  Handbook of perception and human performance , 1986 .

[18]  R W Jones,et al.  Increment and decrement visual thresholds. , 1968, Journal of the Optical Society of America.

[19]  Herbert E. Ives,et al.  A Theory of Intermittent Vision , 1922 .

[20]  Herbert E. Ives,et al.  Critical Frequency Relations in Scotopic Vision , 1922 .

[21]  J. L. Brown.  Harmonic Analysis of Visual Stimuli below Fusion Frequency , 1962, Science.

[22]  J. Roufs.  Dynamic properties of vision. IV. Thresholds of decremental flashes, incremental flashes and doublets in relation to flicker fusion. , 1974, Vision research.

[23]  T. Cohn,et al.  Discrimination of luminance increments and decrements. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[24]  R. M. Herrick.  Foveal luminance discrimination as a function of the duration of the decrement or increment in luminance. , 1956 .