Texture Discrimination and the Analysis of Proximity

Perception ◽  
1979 ◽  
Vol 8 (1) ◽  
pp. 75-91 ◽  
Author(s):  
John Fox ◽  
John E W Mayhew
Keyword(s):  
Visual Processing ◽  
Additional Data ◽  
Analysis Model ◽  
Texture Discrimination ◽  
Proximity Analysis ◽  
Visual Processes ◽  
Early Visual Processing ◽  
Satisfactory Account ◽  
Symmetry Perception ◽  
New Phenomena

A major theory of early visual processing has recently been proposed by Marr, which considers a number of aspects of visual perception in great detail, including grouping and texture discrimination. New phenomena associated with texture discrimination are described and experiments reported which allow a preliminary comparison of Marr's theory, as it applies to texture discrimination, with more established theories such as that due to Julesz. One experiment produced results which are clearly consistent with Marr's account, but the ability of his theory to deal with additional data on region suppression is not established. The theory of the analysis of proximity relations proposed by Fox offers a broadly satisfactory account of many texture perception results, while relying on the more fundamental parts of Marr's theory of primitive visual processes to deal with the remainder. A further attraction of proximity analysis is that it may shed new light on the classical paradox of symmetry perception. Some ways in which the preliminary proximity analysis model is incomplete are discussed, and it is concluded that development of the model may be profitable for theories of early visual processing.

scholarly journals Directional selectivity and its use in early visual processing

1981 ◽  
Vol 211 (1183) ◽  
pp. 151-180 ◽  
Keyword(s):  
Visual Processing ◽  
Visual Motion ◽  
Time Derivative ◽  
Receptive Fields ◽  
Specific Model ◽  
Zero Crossings ◽  
Second Stage ◽  
Early Visual Processing ◽  
Local Direction ◽  
Zero Values

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of ∇ 2 G(x, y) ∗ I(x, y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative ∂[∇ 2 G(x, y) ∗ l(x, y) ]/∂ t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180°. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.

scholarly journals Wide-Field Feedback Neurons Dynamically Tune Early Visual Processing

Neuron ◽  
2014 ◽  
Vol 82 (4) ◽  
pp. 887-895 ◽  
Author(s):  
John C. Tuthill ◽  
Aljoscha Nern ◽  
Gerald M. Rubin ◽  
Michael B. Reiser
Keyword(s):  
Visual Processing ◽  
Wide Field ◽  
Early Visual Processing

Priming from the Attentional Blink: A Failure to Extract Visual Tokens but Not Visual Types

1997 ◽  
Vol 8 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Kimron Shapiro ◽  
Jon Driver ◽  
Robert Ward ◽  
Robyn E. Sorensen
Keyword(s):  
Attentional Blink ◽  
Semantic Priming ◽  
Visual Processing ◽  
Visual Representation ◽  
Stimulus Processing ◽  
Visual Events ◽  
Early Visual Processing ◽  
Location Detection ◽  
Subsequent Target ◽  
Initial Target

When people must detect several targets in a very rapid stream of successive visual events at the same location, detection of an initial target induces misses for subsequent targets within a brief period. This attentional blink may serve to prevent interruption of ongoing target processing by temporarily suppressing vision for subsequent stimuli. We examined the level at which the internal blink operates, specifically, whether it prevents early visual processing or prevents quite substantial processing from reaching awareness. Our data support the latter view. We observed priming from missed letter targets, benefiting detection of a subsequent target with the same identity but a different case. In a second study, we observed semantic priming from word targets that were missed during the blink. These results demonstrate that attentional gating within the blink operates only after substantial stimulus processing has already taken place. The results are discussed in terms of two forms of visual representation, namely, types and tokens.

Spatial frequency analsis in early visual processing

1980 ◽  
Vol 290 (1038) ◽  
pp. 11-22 ◽  
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Spatial Information ◽  
Multiple Channels ◽  
Low Contrast ◽  
Local Sign ◽  
Early Visual Processing ◽  
Low Luminance ◽  
Lowered Sensitivity ◽  
Prior Adaptation

The existence of multiple channels, or multiple receptive field sizes, in the visual system does not commit us to any particular theory of spatial encoding in vision. However, distortions of apparent spatial frequency and width in a wide variety of conditions favour the idea that each channel carries a width- or frequency-related code or ‘label’ rather than a ‘local sign’ or positional label. When distortions of spatial frequency occur without prior adaptation (e.g. at low contrast or low luminance) they are associated with lowered sensitivity, and may be due to a mismatch between the perceptual labels and the actual tuning of the channels. A low-level representation of retinal space could be constructed from the spatial information encoded by the channels, rather than being projected intact from the retina.

scholarly journals Effects of attentional load on early visual processing depend on stimulus timing

2011 ◽  
Vol 33 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Karsten Rauss ◽  
Gilles Pourtois ◽  
Patrik Vuilleumier ◽  
Sophie Schwartz
Keyword(s):  
Visual Processing ◽  
Early Visual Processing ◽  
Attentional Load ◽  
Stimulus Timing

scholarly journals A connectivity-constrained computational account of topographic organization in high-level visual cortex

2021 ◽  
Author(s):  
Nicholas M Blauch ◽  
Marlene Behrmann ◽  
David Plaut
Keyword(s):  
Visual Processing ◽  
Spatial Organization ◽  
Functional Organization ◽  
Spatial Clusters ◽  
Feature Extracting ◽  
Domain Specific ◽  
Visual Processes ◽  
Topographic Organization ◽  
High Level ◽  
Multiple Domain

Inferotemporal cortex (IT) in humans and other primates is topographically organized, with multiple domain-selective areas and other general patterns of functional organization. What factors underlie this organization, and what can this neural arrangement tell us about the mechanisms of high level vision? Here, we present an account of topographic organization involving a computational model with two components: 1) a feature-extracting encoder model of early visual processes, followed by 2) a model of high-level hierarchical visual processing in IT subject to specific biological constraints. In particular, minimizing the wiring cost on spatially organized feedforward and lateral connections within IT, combined with constraining the feedforward processing to be strictly excitatory, results in a hierarchical, topographic organization. This organization replicates a number of key properties of primate IT cortex, including the presence of domain-selective spatial clusters preferentially involved in the representation of faces, objects, and scenes, within-domain topographic organization such as animacy and indoor/outdoor distinctions, and generic spatial organization whereby the response correlation of pairs of units falls off with their distance. The model supports a view in which both domain-specific and domain-general topographic organization arise in the visual system from an optimization process that maximizes behavioral performance while minimizing wiring costs.

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