Journal ArticleDOI
Spatial summation in lateral geniculate nucleus and visual cortex.
Helen E. Jones,Ian Max Andolina,Nicola M. Oakely,Penelope C. Murphy,Penelope C. Murphy,Adam M. Sillito +5 more
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TLDR
The data suggest that the strongest input to cortical cells will arise from geniculate cells representing areas of visual space located at the borders of a visual stimulus, and suggests that analysis of response properties by patterns centred over the receptive fields of cells may give a misleading impression of the process of the representation.Abstract:
We have compared the spatial summation characteristics of cells in the primary visual cortex with those of cells in the dorsal lateral geniculate nucleus (LGN) that provide the input to the cortex. We explored the influence of varying the diameter of a patch of grating centred over the receptive field and quantitatively determined the optimal summation diameter and the degree of surround suppression for cells at both levels of the visual system using the same stimulus parameters. The mean optimal summation size for LGN cells (0.90°) was much smaller than that of cortical cells (3.58°). Virtually all LGN cells exhibited strong surround suppression with a mean value of 74%±1.61% SEM for the population as a whole. This potent surround suppression in the cells providing the input to the cortex suggests that cortical cells must integrate their much larger summation fields from the low firing rates associated with the suppression plateau of the LGN cell responses. Our data suggest that the strongest input to cortical cells will arise from geniculate cells representing areas of visual space located at the borders of a visual stimulus. We suggest that analysis of response properties by patterns centred over the receptive fields of cells may give a misleading impression of the process of the representation. Analysis of pattern terminations or salient borders over the receptive field may provide much more insight into the processing algorithms involved in stimulus representation.read more
Citations
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Journal ArticleDOI
Do we know what the early visual system does
Matteo Carandini,Jonathan B. Demb,Valerio Mante,David J. Tolhurst,Yang Dan,Bruno A. Olshausen,Jack L. Gallant,Nicole C. Rust +7 more
TL;DR: Research is progressing with the goals of defining a single “standard model” for each stage of the visual pathway and testing the predictive power of these models on the responses to movies of natural scenes, which would be an invaluable guide for understanding the underlying biophysical and anatomical mechanisms and relating neural responses to visual perception.
Book ChapterDOI
Contribution of feedforward, lateral and feedback connections to the classical receptive field center and extra-classical receptive field surround of primate V1 neurons
TL;DR: In this article, the authors proposed specific mechanisms by which each connection type contributes to the receptive field (RF) center and surround of V1 neurons, and implement these hypotheses into a recurrent network model.
Journal ArticleDOI
Inhibitory Stabilization of the Cortical Network Underlies Visual Surround Suppression
TL;DR: It is found that observed cell-to-cell variability in surround effects, from facilitation to suppression, can arise naturally from variability in the ISN, in which V1 operates as an inhibition-stabilized network (ISN), in which excitatory recurrence alone is strong enough to destabilize visual responses but feedback inhibition maintains stability.
Journal ArticleDOI
Surround suppression in primate V1
TL;DR: The zones driving the suppressive influences and the direction contrast facilitation were often spatially heterogeneous and for a number of cells bore strong comparison with the class of behavior reported for surround mechanisms in MT, suggesting a potential role in extracting information about motion contrast in the representation of the three dimensional structure of moving objects.
Journal ArticleDOI
Always returning: feedback and sensory processing in visual cortex and thalamus
TL;DR: A circuit formed by layer 6 feedback cells in the visual cortex is considered and how this straddles the retinothalamic and thalamocortical transfer of visual input and it is suggested that motion perception involves a dynamic interplay between MT, V1 and the thalamus.
References
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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
Columnar specificity of intrinsic horizontal and corticocortical connections in cat visual cortex
TL;DR: The extent of the horizontal connections, which allows single cells to integrate information over larger parts of the visual field than that covered by their receptive fields, and the functional specificity of the connections, suggests possible roles for these connections in visual processing.
Journal ArticleDOI
Neurotransmitter actions in the thalamus and cerebral cortex and their role in neuromodulation of thalamocortical activity.
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.
Journal ArticleDOI
Receptive field dynamics in adult primary visual cortex
TL;DR: The results indicate that the topographic reorganization within the cortex was largely due to synaptic changes intrinsic to the cortex, perhaps through the plexus of long-range horizontal connections.