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Saccadic suppression is a decline in detectability of a weak flash presented during a saccadic eye movement. We examined the hypothesis of Matin [Psychol. Bull. 81, 899 (1974)] that saccadic suppression may be due to increased stimulus uncertainty during the saccade. Uncertainty could arise from variability and inhomogeneities in the visual frame of(More)
Time-averaged human electroretinogram (ERG) responses were determined for several workplace visual stimuli which are temporally modulated at rates exceeding the perceptual critical fusion frequency (CFF). A clearly identifiable synchronous response was in evidence for a video display terminal (VDT) stimulus operating with a refresh rate as high as 76 Hz. A(More)
The detectability of a brief color shift towards red or towards green of a foveally viewed yellow target is less by 25% if the observer is uncertain as to the direction of the color shift. This result matches a prediction of the theory of signal detectability: When signal parameters become uncertain, detectability declines.
The pupil oscillates in synchrony with a slow beat produced by adding two lights flickering at slightly different frequencies. This behavior shows that nonlinear processes are present within the pathway. To localize these processes, a light of one frequency was presented to one eye, while a light of a different frequency was presented to the other. No pupil(More)
Designers are often asked to gauge the influence of an illuminant or a visual signal on the human eye in a particular application. It has long been known that physical measurement is insufficient for this purpose. This is, in part, because the human sense of vision is not equipped with a competent radiation detector that is independent of wavelength. " The(More)
This paper describes psychophysical methodology, more precise than conventional photometry, to evaluate the visual effect of LED railroad grade crossing signals. LED devices are attractive replacements for incandescent railroad crossing signals. Up to 700% longer life, 75% lower energy consumption, 300% longer battery operation, and communication(More)
We employed vertical sinusoidal test gratings to search for spatial adaptation to lower-case text presented on a standard video display terminal. The parameters of the contrast sensitivity test were selected on the basis of waveform analysis of horizontal spatial luminance profiles of the text. We found that subjects exhibited a small (4-5 dB), but(More)
A limited set of illuminants and phosphor colors are commonly used in video display terminal (VDT) working environments. This study attempts to identify any combinations of such conditions that influence performance on a visually demanding counting task. Experiments were performed to test whether the phosphor color, ambient lighting spectrum, or temporal(More)
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