Electrophysiological evidence for the existence of orientation and size detectors in the human visual system
F. W. Campbell,L. Maffei +1 more
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TLDR
The evoked potential in response to a grating alternating in phase at 8 c/s was recorded as a function of contrast from the occiput of man.Abstract:
1 The evoked potential in response to a grating alternating in phase at 8 c/s was recorded as a function of contrast from the occiput of man
2 It was found that a linear relation exists between the log of contrast and the amplitude of the evoked potential
3 Extrapolation to zero amplitude voltage of the regression line between the amplitude of the evoked potential and log contrast predicts the psychophysical threshold This law was found to hold over the wide range of spatial frequencies tested
4 Below 3 c/deg the results are best fitted with two regression lines; one of these is generated from the foveal and the other from the parafoveal representation in the cortex
5 The slope of the regression lines was found to be almost independent of either the spatial frequency or the area of the stimulus grating
6 The slope of the regression lines could be markedly increased by using as a stimulus either two different spatial frequencies, or two different orientations, presented simultaneously
7 Using the evoked potential the selectivity to orientation was found to be so high that a channel was not influenced by another orientation 15° away
8 The channels selectively sensitive to spatial frequency were highly selective and were not influenced by another spatial frequency one octave removed in spatial frequency
9 It is concluded that in man there exist neurones highly selective to both orientation and spatial frequencyread more
Citations
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Speedy evoked potential methods for assessing vision in normal and amblyopic eyes: Pros and cons
TL;DR: The present note attempts to provide a concise summary of the pros and cons of the method with the aim of aiding potential users to decide whether the “sweep averaging” method would offer them sufficient advantage over conventional recording to justify switching to an unfamiliar technique.
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Influence of spatial frequency and handedness on hemispheric asymmetry in visually steady-state evoked potentials.
TL;DR: Recorded steady-state evoked potentials suggested the existence of two transient and sustained systems in the hemispheric lateralization, and both the spatial and temporal parameters were relevant to the lateralization.
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Spatial Contrast Sensitivity Vision Loss in Children with Cortical Visual Impairment
TL;DR: The results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI, and suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.
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Electrophysiological correlates of hyperacuity in the human visual cortex.
TL;DR: This work reports here an electrophysiological correlate of hyperacuity recorded from the human visual cortex, where the amplitude of the visually evoked potentials elicited by the appearance of a vernier offset varied systematically with the magnitude of the offset.
Journal ArticleDOI
Visual masking at different polar angles in the two-dimensional Fourier plane.
Lewis O. Harvey,Vy V. Doan +1 more
TL;DR: The threshold elevation surfaces produced by the masks lead to the following conclusions: spatial-frequency bandwidth is independent of mask orientation and has a value of approximately 2 octaves, orientation bandwidth is wider for oblique masks than for horizontal and vertical masks, the principle of spectral polar separability is violated, and two-dimensional Gabor functions in the frequency domain account for the masking effects.
References
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Journal ArticleDOI
Receptive fields, binocular interaction and functional architecture in the cat's visual cortex
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: This method is used to examine receptive fields of a more complex type and to make additional observations on binocular interaction and this approach is necessary in order to understand the behaviour of individual cells, but it fails to deal with the problem of the relationship of one cell to its neighbours.
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 of single neurones in the cat's striate cortex
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: The present investigation, made in acute preparations, includes a study of receptive fields of cells in the cat's striate cortex, which resembled retinal ganglion-cell receptive fields, but the shape and arrangement of excitatory and inhibitory areas differed strikingly from the concentric pattern found in retinalganglion cells.
Journal ArticleDOI
Application of fourier analysis to the visibility of gratings
F. W. Campbell,John G. Robson +1 more
TL;DR: The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies and the results show clear patterns of uniformity in the response to grating noise.
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.
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