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Biomedical subjects

D H Westendorf

Publications and source records attributed to D H Westendorf.

10 recordsLinked to original sources
PubMed1989

Binocular rivalry and dichoptic masking: suppressed stimuli do not mask stimuli in a dominating eye.

Reaction time was used to gauge the sensitivity of an eye during its dominant and suppressed phases of binocular rivalry. During dominance, performance was uniformly good in detecting both stimuli that were spatially identical to the suppressed stimulus and those that were different in spatial frequency. When suppressed eyes were tested, performance was poor when the stimulus was different from the dominating stimulus, but even worse when the test stimulus and the dominating stimulus were spatially identical. The results favor the view that suppression operates nonselectively on a monocular visual channel, prior to the point at which dichoptic pattern masking occurs.

Attention↗
PubMed1980

What is suppressed during binocular rivalry?

To answer the question 'what is suppressed during binocular rivalry?" a series of three experiments was performed. In the first experiment observers viewed binocular rivalry between orthogonally oriented patterns. When the dominant and suppressed patterns were interchanged between the eyes observers continued seeing with the dominant eye, indicating that an eye, not a pattern, is suppressed during rivalry. In a second experiment it was found that a suppressed eye was able to contribute to stereopsis. A third experiment demonstrated that the predominance of an eye could be influenced by prior adaptation of the other eye, indicating that binocular mechanisms participate in the rivalry process.

Adaptation, Ocular↗
PubMed1978

Word recall as a function of bisensory and unisensory split-span task presentation and modality preferences.

This study investigated the effects of visual and auditory modality preferences on work recall in bisensory and unisensory split-span tasks. Subjects tended to perform better in the bisensory rather than unisensory condition. Modality preferences (n = 72 subjects) were generally unrelated to performance in these experimental conditions. These findings suggest that preferences for a modality are better characterized as response biases rather than as increased processing capacity for preferred modality material.

Attention↗
PubMed1976

Falcon visual acuity.

Grating acuity, the ability to resolve high-contrast square-wave gratings, was measured in a falcon and in humans under comparable conditions. This behavioral test of falcon acuity supports the common belief that Falconiformès have superb vision-the faclon's threshold was 160 cycles per degree, while the human thresholds were 60 cycles per degree. Falcon acuity, however, was much more dependent on lumanance, declining sharply with decreases in luminance.

Animals↗