Effect on perception of hue of imposed oscillatory movements of a stabilized retinal image.
A stabilized image of a coloured square seen against a black background was produced. After the image had faded, oscillatory movements were applied in a direction parallel to a diagonal so that all boundaries had an equal component of motion normal to themselves. Movements of different frequency, amplitude and wave-form were studied. Most of the experiments were carried out at fairly high retinal illuminance (80-500 td). The objective was to find the amplitude and frequency required for perception of hue and saturation. It was found that these movements had (i) a minimum amplitude of about 5' (10' peak-to-peak), (ii) a minimum velocity of 15'(-1) and (iii) a frequency range from about 1 Hz to about 4 Hz. The movements required are larger than those required for perception of the shape of the target and also larger than the normal movements which remain when a subject fixates a well-defined mark. Also the movements associated with the perception of hue and saturation are restricted to a narrower frequency range. These features probably imply that it is necessary to excite numbers of cones covering a minimum area to give perception of hue and saturation.
D003118:Color Perception / Q000502:physiology*; D005403:Fixation, Ocular; D006801:Humans; D008027:Light; D009039:Motion Perception / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D013053:Spectrophotometry