I will re-check all the data and give it another try, the next clear night, and let you know. I then went into my location box and saved it as Tyner NC and use that as my home location. When I just started using Starry Night I put in my zip code (27980) to find my location, but it didn't work very well, so I used the Latitude and Longitude boxes to fill in my location, which I think work good. If necessary I can send you some screen shots of each. I usually use an 26 or 27 mm eyepiece to get started. These are the coordinates I have set in the HC and also in Starry Night. As for the location are you referring to my location coordinates, (Tyner, NC.) which are Latitude: 36 degrees 14' N, Longitude -76 degrees 40' W, and elevation of 6 meters. Even if the visual surround (terrain) contributes to the moon illusion as reported by Kaufman and Rock, this contribution is likely to be mediated by the state of the oculomotor system, not by a size-distance invariance mechanism, or size constancy scaling.When I start up the mount I always set the time by the time on my computer (not to the seconds). Several other studies have also suggested an involvement of the oculomotor system in the moon illusion. All of these findings disagree with the apparent-distance theory for the moon illusion. A drastic change in the perceived distance of the simulated moon was found to induce only a small change in its apparent size. Thus, Holway and Boring's (1940) and Taylor and Boring's (1942) findings, which Kaufman and Rock had discredited, were partly supported. However, the moon illusion can be obtained in complete darkness, and the viewing angle coupled with binocular viewing was found to have a great contribution to the illusion. Kaufman and Rock claimed that the visible terrain is essential for the moon illusion to occur. In the present study, Kaufman and Rock's (1962) well-known study on the moon illusion was reexamined in light of findings reported after its publication. We propose that such changes in subjective perception of size are mediated by mechanisms that scale with the extent to which an individual's V1 selectively represents the central visual field. Therefore, subjective size perception correlated with variability in central cortical magnification rather than the anatomical extent of primary visual cortex. Control analyses showed no correlations between behavioral measures and the overall V1 area estimated probabilistically on the basis of neuroanatomy alone. However, participants' objective ability to discriminate the size of objects presented in isolation was unrelated to illusion strength and did not correlate with V1 area. We found that individual differences in the magnitudes of the illusion produced by either type of context were correlated with V1 area defined through retinotopic mapping using functional MRI. Here we studied in healthy adult humans how two different types of context (large or small inducers) in this illusion affected size perception by comparing each to a reference stimulus without any context. Previous work implicates human primary visual cortex (V1) as the neural substrate mediating this contextual effect. In the Ebbinghaus illusion, the context surrounding an object modulates its subjectively perceived size. Our findings suggest that area V1 is actively involved in reshaping our perception to match the short-term statistics of the visual scene. A model based on local inhibitory V1 mechanisms simulated the inward or outward shifts of the stimulus contours and hence the perceptual effects. In a human fMRI study, we measured the blood oxygen level-dependent activation (BOLD) responses of the primary visual cortex (V1) to the contours of large-diameter stimuli and found that activation closely matched the perceptual rather than the retinal stimulus size: the activated area of V1 increased or decreased, depending on the size of the preceding stimulus. Here, we show that the perceived size of a stimulus is significantly affected by the context of the scene: brief previous presentation of larger or smaller adapting stimuli at the same region of space changes the perceived size of a test stimulus, with larger adapting stimuli causing the test to appear smaller than veridical and vice versa. In natural scenes, objects rarely occur in isolation but appear within a spatiotemporal context.
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