Tuning of orientation detectors in human vision.
A new method to study the tuning of orientation detectors in the human visual system is proposed. The stimulus consists of a sequence of flashed sinusoidal gratings of random orientations and spatial phases shown at a fast presentation rate. The subject's task is to report, as fast as possible, when the presence of a particular orientation (horizontal, vertical, or oblique) is seen in the stimulus sequence by pressing a button. The data are analyzed by calculating the empirical distribution of orientations present in the stimulus sequence within an optimal time-window before the button was pressed. The resulting orientation distributions show a "Mexican hat" shape, which resembles the distributions obtained in some single neurons of monkey primary visual cortex using a similar method (Ringach et al., 1997). The findings are consistent with the idea of "lateral inhibition" between neighboring detectors in the orientation domain.
Ringach
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Center for Neural Science, New York University, NY 10003, USA.
D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008959:Models, Neurological; D009433:Neural Inhibition; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics; D011930:Reaction Time; D012399:Rotation; D014793:Visual Cortex / Q000502:physiology*