Mechanisms of contour perception in monkey visual cortex. I. Lines of pattern discontinuity
R. von der Heydt,E. Peterhans +1 more
Reads0
Chats0
TLDR
It is concluded that contours may be defined first at the level of V1, while the unresponsiveness of neurons in V1 to this type of anomalous contour is in agreement with linear filter predictions, the responses of V2 neurons need to be explained.Abstract:
We have studied the mechanism of contour perception by recording from neurons in the visual cortex of alert rhesus monkeys. In order to assess the relationship between neural signals and perception, we compared the responses to edges and lines with the responses to patterns in which human observers perceive a contour where no line or edge is given (anomalous contour), such as the border between gratings of thin lines offset by half a cycle. With only one exception out of 60, orientation-selective neurons in area V1 did not signal the anomalous contour. Many neurons failed to respond to this stimulus at all, others responded according to the orientation of the grating lines. In area V2, 45 of 103 neurons (44%) signaled the orientation of the anomalous contour. Sixteen did so without signaling the orientation of the inducing lines. Some responded better to anomalous contours than to the optimum bars or edges. Preferred orientations and widths of tuning for anomalous contour and bar or edge were found to be highly correlated, but not identical, in each neuron. Similar to perception, the neuronal responses depended on a minimum number of lines inducing the contour, but not so much on line spacing, and tended to be weaker when the lines were oblique rather than orthogonal to the border. With oblique lines, the orientations signaled were biased towards the orientation orthogonal to the lines, as in the Zollner illusion. We conclude that contours may be defined first at the level of V2. While the unresponsiveness of neurons in V1 to this type of anomalous contour is in agreement with linear filter predictions, the responses of V2 neurons need to be explained. We assume that they sum the signals of 2 parallel paths, one that defines edges and lines and another that defines anomalous contours by pooling signals from end-stopped receptive fields oriented mainly orthogonal to the contour.read more
Citations
More filters
Journal ArticleDOI
Distributed Hierarchical Processing in the Primate Cerebral Cortex
TL;DR: A summary of the layout of cortical areas associated with vision and with other modalities, a computerized database for storing and representing large amounts of information on connectivity patterns, and the application of these data to the analysis of hierarchical organization of the cerebral cortex are reported on.
Journal Article
A sensorimotor account of vision and visual consciousness-Authors' Response-Acting out our sensory experience
J. Kevin O'Regan,Alva Noë +1 more
TL;DR: In this article, the authors propose that the brain produces an internal representation of the world, and the activation of this internal representation is assumed to give rise to the experience of seeing, but it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness.
Journal ArticleDOI
A sensorimotor account of vision and visual consciousness
J. Kevin O'Regan,Alva Noë +1 more
TL;DR: In this article, the authors propose that the brain produces an internal representation of the world, and the activation of this internal representation is assumed to give rise to the experience of seeing, but it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness.
Journal ArticleDOI
Information Processing in the Primate Visual System: An Integrated Systems Perspective
TL;DR: The primate visual system contains dozens of distinct areas in the cerebral cortex and several major subcortical structures that are extensively interconnected in a distributed hierarchical network that contains several intertwined processing streams.
Journal ArticleDOI
Neuronal responses to static texture patterns in area V1 of the alert macaque monkey
James J. Knierim,D. C. Van Essen +1 more
TL;DR: Responses from neurons in area V1 of the alert macaque monkey to textured patterns modeled after stimuli used in psychophysical experiments of pop- out are consistent with a possible functional role of V1 cells in the mediation of perceptual pop-out and in the segregation of texture borders.
References
More filters
Journal ArticleDOI
Receptive fields and functional architecture of monkey striate cortex
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: The striate cortex was studied in lightly anaesthetized macaque and spider monkeys by recording extracellularly from single units and stimulating the retinas with spots or patterns of light, with response properties very similar to those previously described in the cat.
Journal ArticleDOI
Receptive fields and functional architecture in two nonstriate visual areas (18 and 19) of the cat.
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: To UNDERSTAND VISION in physiological terms represents a formidable problem for the biologist, and one approach is to stimulate the retina with patterns of light while recording from single cells or fibers at various points along the visual pathway.
Journal ArticleDOI
Anatomy and physiology of a color system in the primate visual cortex.
TL;DR: The results suggest that a system involved in the processing of color information, especially color-spatial interactions, runs parallel to and separate from the orientation-specific system.
Journal ArticleDOI
Spatial frequency selectivity of cells in macaque visual cortex
TL;DR: Among other things, it is shown that many stirate cells have quite narrow spatial bandwidths and at a given retinal eccentricity, the distribution of peak frequency covers a wide range of frequencies; these findings support the basic multiple channel notion.
Journal ArticleDOI
Spatial summation in the receptive fields of simple cells in the cat's striate cortex.
TL;DR: The responses of simple cells in the cat's atriate cortex to visual patterns that were designed to reveal the extent to which these cells may be considered to sum light‐evoked influences linearly across their receptive fields are examined.
Related Papers (5)
Receptive fields and functional architecture of monkey striate cortex
David H. Hubel,Torsten N. Wiesel +1 more
Receptive fields, binocular interaction and functional architecture in the cat's visual cortex
David H. Hubel,Torsten N. Wiesel +1 more