Skip to content
Free planNo credit card requiredStart writing
AI for Research home
AI for Research home
Dashboard
Sign inGet started

Search 250 million research papers

Read the abstract, see who wrote it and who cites it, and get the citation in APA, MLA, Chicago or Harvard.

About 10,000 papers for “Visual processing”

Motion processing in visual cortex

John H. R. Maunsell · Annual Meeting Optical Society of America · 1989

Many lines of anatomical and physiological evidence have shown that the visual system contains a distinct pathway that is responsible for most motion analysis. In primates this pathway originates in the retinal ganglion cells that send their axons to the magnocellular layers of the lateral geniculate nucleus (LGN). The outputs from the magnocellular LGN layers directly provide the primary excitatory drive to structures like layer 4B in striate cortex and the middle temporal area (MT) in extrastriate cortex. Both of these structures contain a high proportion of neurons that are selective for the direction of stimulus motion. Later stages of motion processing in parietal cortex appear to contribute to analyzing more complex types of movement such as rotation or looming.

Cited by 0

Corticogeniculate Feedback and Visual Processing

W. Martin Usrey · 2023

Abstract Neurons in the lateral geniculate nucleus (LGN) relay feedforward visual signals from the retina to the cortex. These same neurons also receive extensive feedback input from the cortex. Although corticogeniculate feedback is the single greatest source of synaptic input to LGN neurons, researchers are just beginning to gain an understanding of how corticogeniculate feedback affects visual processing. Results from an increasing number of studies provide important insight into both the organization and function of corticogeniculate feedback. These results demonstrate that feedback projections are organized into parallel streams and can influence both the spatial and temporal properties of visual responses in the LGN, which ultimately affects the signals communicated to the cortex. Importantly, the corticogeniculate pathway cannot be understood when viewed in isolation, as it is an integral part of a geniculo-cortico-geniculate circuit that interconnects the thalamus and the cortex for visual processing.

Cited by 0

Visual processing out of awareness

Isaacs Paternostro, D. · Utrecht University Repository (Utrecht University)

The current experiment was designed to find a possible common denominator between the target and distractor that causes a subliminal influence on behavior. The color of a stimulus was suppressed by visual backward masking to find out what influence it would have on the global effect compared to other conditions, such as different suppressed colors or supraliminal conditions. Observers were told to make fast eye-movements to a stimulus target to be assured of a global effect in the baseline condition. The subliminal conditions did have a specific influence on the saccades; they decreased saccade latency and increased the global effect. The observers did not process the surface color of the subliminal stimulus as no significant difference between subliminal conditions has been found in this study.

Cited by 0Open access

THE FRAMEWORK: CASCADED VISUAL PROCESSING

J. Anthony, Movshon, Eero P. Simoncelli · 2016

The perception of complex visual patterns emerges from neuronal activity in a cascade of areas in the primate cerebral cortex. We have probed the early stages of this cascade with “naturalistic ” texture stimuli designed to capture key statistical features of natural images. Humans can recognize and classify these synthetic images and are insensitive to distortions that do not alter the local values of these statistics. The responses of neurons in the primary visual cortex, V1, are relatively insensitive to the statistical information in these textures. However, in the area immediately downstream, V2, cells respond more vigorously to these stimuli than to matched control stimuli. Humans show blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI responses in V1 and V2) that are consistent with the neuronal measurements in macaque. These fMRI measurements, as well as neurophysiological work by others, show that true natural scenes become a more prominent driving feature of cortex downstream from V2. These results suggest a framework for thinking about how information about elemen-tary visual features is transformed into the specific representations of scenes and objects found in areas higher in the visual pathway.

Cited by 0

Visual processing of motion boundaries

W. L. Sachtler, Qasim Zaidi · Vision Research · 1995

Psychometric functions for motion detection were measured for various spatial velocity profiles made of independently moving lines of random dots. In the first experiment, sensitivity was greater for square-wave velocity profiles than for sine waves of the same fundamental spatial frequency. Sensitivity for square waves depended on the phase of the waveform with respect to the fixation point, which precludes a characterization of the processes underlying the detection of shearing motion as a translation-invariant system. The second experiment, using velocity fields created by spatial super-position of sine waves, showed that motion boundaries facilitate detection of motion due to the steepness of the velocity gradient, and not simply because of added power at higher harmonics. In the third experiment, fluted velocity waveforms were created by subtracting the fundamental sinusoidal component from square waves, retaining sharp motion boundaries between opposing directions but removing the regions of uniform motion. Subtracting the fundamental from low-frequency square waves did not lower sensitivity to motion, indicating that sensitivity was largely determined by the presence of motion boundaries. In the final section of this article, a model is presented that can account for the data by using linear center-surround velocity mechanisms whose sizes increase with eccentricity while their sensitivity for shearing motion decreases.

Cited by 32Open access

Visual processing and learning disorders

Harold P. Koller · Current Opinion in Ophthalmology · 2012

Recent neuropsychology discoveries have helped in the prevention, evaluation and treatment of children with visual processing and learning disorders. Quality-of-life and educational efficiency therefore can be improved.

Cited by 10

Early Processing of Visual Information.

Marr,David · DSpace@MIT (Massachusetts Institute of Technology) · 1975

The article describes a symbolic approach to visual information proessing, and set out four principles that appear to govern the design of comples symbolic information processing systems. A computational theory of early visual information is presented, which extends to about the level of figure-ground separation. It includes a process-oriented theory of texture vision. Most of the theory has been implemented, and examples are shown of the analysis of several natural images. This replaces AIM-324 and AIM 334.

Cited by 0Open access

Visual Processing in Texture Segregation

Jacob Beck · 1989

Abstract : Two types of texture segregation occurs. Preattentive texture segregation has been shown to occur as a result of differences in the outputs of Gabor filters that operate on intensity values and as a result of the grouping of discrete elements through edge alignment and lightness similarity. Texture segregation based on these properties occurs preattentively. A second type of texture segregation appears to depend on attention. Texture segregation based on the 3D interpretation of projected shapes appears to require a focusing of attention. Attention acts to trigger texture segregation. Attention is required to see a 2D figure as three-dimensional. The 3D interpretation is propagated in parallel or rapidly to the other figures in the pattern and texture segregation occurs in terms of the differences in the perceived orientations off the 3D figures. A necessary condition for texture segregation is the rapid processing of stimulus differences. Texture segregation does not occur if discrimination of the relevant stimulus differences requires sequential attentional processing. Vision, Texture segregation.

Cited by 3