Resistance to positional noise in human vision
Article Abstract:
The world around us, as perceived by our visual systems, seems solid and unmovable, despite the fact that our eyes are constantly jumping around and quivering. Even when trying to fixate on one particular spot, the human eye is in constant and rapid motion. Some researchers have suggested that the visual system improves what would otherwise be a blurred image by compensating for linear motion. In other words, as the image moves across the retina in constant motion, the motion might be taken into account to produce a non-blurred image. Experiments have now shown that this cannot be the case, and that the information processing taking place in the visual system is more sophisticated than previously thought. The basic task was straightforward; subjects were shown a pair of closely spaced lines for 600 milliseconds (ms). After 100 ms darkness, a second pair of lines was shown and the observer asked to determine if they were wider or narrower than the first pair. Unlike previous studies in which similar pairs were moved across the visual field in a linear fashion, the line pairs were displaced randomly every 30 ms within a narrow area. If the current notions were correct, the visual system could not compensate for the random, unpredictable position changes of the lines. The subjects preformed the task precisely, however, and the movement did not significantly degrade their visual discrimination. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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Visual synchrony affects binding and segmentation in perception
Article Abstract:
Information is analyzed by the visual system by the decomposition of complex objects into simple components, distributed widely throughout the cortex.A process to group together visual features belonging to each object is required when several objects a present in the visual field simultaneously. Visual grouping was found to be facilitated when elements of one percept were presented simultaneously, but were temporally separated from another percept. Binding if found to be due to a global process of grouping due to synchronous neural activation.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Natural symmetry
Article Abstract:
Brain imaging plays an important role in reshaping ones views of the links between human and animals, especially in relation to cognition, emotion and all 'private' mental states. This methodology provides physical insight into mental states in humans, allowing direct comparison with mental states in animals.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2005
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