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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Journal ArticleDOI
The effect of adaptation to the stimulating pattern on the latency and wave form of visual evoked potentials
TL;DR: Visual evoked potentials elicited with a checkerboard stimulus after adaptation to an unpatterned grey field were compared to those obtained after adaptationto the stimulating pattern for an equal interval of time, suggesting that adaptation may cause the wave form differences in the VEPs obtained by these two methods.
Journal ArticleDOI
Corners, receptive fields, and visually evoked cortical potentials
TL;DR: In this paper, two sets of stimulus patterns were used, one with sharp corners and one with the corners rounded off, each set ranged in angularity from 180 to 45 degrees in 45-deg steps.
Journal ArticleDOI
Effects of grating spatial orientation on visual evoked potentials and contrast sensitivity in multiple sclerosis.
F Logi,A Pellegrinetti,Luca Bonfiglio,O Baglini,Gabriele Siciliano,Ludice A,Ferdinando Sartucci +6 more
TL;DR: It is concluded that the use of vertical grating in clinical routine is more reliable both for PVEPs and CS testing; in addition CS can be abnormal even with normal PVPs: this could mean an early impairment of CS and provide useful indications about a subclinical involvement of visual cortex.
Book ChapterDOI
Stimulus Field, Element Size and Human Visually Evoked Cortical Potentials
TL;DR: In this article, the spatial frequency (element size) characteristics at the central retina by use of a TV technique were studied in a number of experiments in which orientation of a pattern, field size, retinal position, defocusing grade were altered.
Journal ArticleDOI
Electrophysiological assessment of the human depth-perception threshold.
TL;DR: The cortical response to stereoscopic stimuli was measured as a function of disparity using visual evoked potentials (VEP) and an estimation of the stereo threshold by linear extrapolation was conducted.
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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On the existence of neurones in the human visual system selectively sensitive to the orientation and size of retinal images.
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