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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The effect of nitrous oxide on the relation between the evoked potential and contrast threshold.
TL;DR: Averaged potentials evoked by presenting grating stimuli at a rate of 1 Hz were recorded from the human scalp, and compared with psychophysical contrast threshold for the same patterns and it was confirmed that the late wave (P2) correlated with the pattern detection.
Journal ArticleDOI
Lack of positive results of a physiologically based treatment of amblyopia.
TL;DR: It is suggested that brief exposure to the grating patterns had little if any beneficial effect on visual acuity in amblyopic eyes.
Journal ArticleDOI
Changes in spatial selectivity of pattern-ERG components with stimulus contrast
Matthias Korth,R. Rix +1 more
TL;DR: The data indicate that if pattern-related responses activated by antagonistic receptive fields are to be studied, low contrast values should be employed and attention should be paid to the negative component of the response.
Journal ArticleDOI
Processing Deficits in Primary Visual Cortex of Amblyopic Cats
TL;DR: The modulation of responses in cat V1 to gratings at different orientations and spatial frequencies is investigated with optical imaging of intrinsic signals to reveal a close correlation between the loss of visual acuity in amblyopia as assessed by VEPs and the modulation of neuronal activation as seen by optical imagingof intrinsic signals.
Journal ArticleDOI
The orientation anisotropy and orientation constancy: a visual evoked potential study.
Barrie J. Frost,Jehuda J Kaminer +1 more
TL;DR: It was concluded that the site of orientation constancy is located either at higher levels of the primary visual system or in the second visual system, and direction of displacement could not have been contributing to the effect.
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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