Asynchronous maturation of visual system structures: Lessons from color blindness

Differential hysteresis processing is a new image processing technology that provides a tool for the display of image data information at any level of differential contrast resolution. This includes the maximum contrast resolution of the acquisition system which may be 1,000-times higher than that of the visual system (16 bit versus 6 bit). All microscopes acquire high precision contrasts at a level of <0.01-25% of the acquisition range in 16-bit - 8-bit data, but these contrasts are mostly invisible or only partially visible even in conventionally enhanced images. The processing principle of the differential hysteresis tool is based on hysteresis properties of intensity variations within an image.Differential hysteresis image processing moves a cursor of selected intensity range (hysteresis range) along lines through the image data reading each successive pixel intensity. The midpoint of the cursor provides the output data. If the intensity value of the following pixel falls outside of the actual cursor endpoint values, then the cursor follows the data either with its top or with its bottom, but if the pixels' intensity value falls within the cursor range, then the cursor maintains its intensity value.

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Functional imaging of the visual system

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(97)88161-1 ◽

1997 ◽

Vol 103 (1) ◽

pp. 56

Author(s):

H Spekreijse

Keyword(s):

Visual System ◽

Functional Imaging

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Atypical congenital monochromatism. A new pedigree of total color blindness with chromosomal studies

Archives of Internal Medicine ◽

10.1001/archinte.118.5.491 ◽

1966 ◽

Vol 118 (5) ◽

pp. 491-493 ◽

Cited By ~ 1

Author(s):

J. M. Earll

Keyword(s):

Color Blindness

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Newborn's Preference for Faces

European Psychologist ◽

10.1027/1016-9040.1.3.200 ◽

1996 ◽

Vol 1 (3) ◽

pp. 200-205 ◽

Cited By ~ 12

Author(s):

Carlo Umiltà ◽

Francesca Simion ◽

Eloisa Valenza

Keyword(s):

Visual System ◽

Structural Properties ◽

Sensory Properties ◽

Human Face ◽

System Experiment ◽

Face Experiment

Four experiments were aimed at elucidating some aspects of the preference for facelike patterns in newborns. Experiment 1 showed a preference for a stimulus whose components were located in the correct arrangement for a human face. Experiment 2 showed a preference for stimuli that had optimal sensory properties for the newborn visual system. Experiment 3 showed that babies directed their attention to a facelike pattern even when it was presented simultaneously with a non-facelike stimulus with optimal sensory properties. Experiment 4 showed the preference for facelike patterns in the temporal hemifield but not in the nasal hemifield. It was concluded that newborns' preference for facelike patterns reflects the activity of a subcortical system which is sensitive to the structural properties of the stimulus.

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