Cortical responses to light in unanesthetized monkeys and their alteration by visual system lesions

Hg, Vaughan; Cg, Gross

doi:10.1007/bf00234923

Cited by 48 publications

(13 citation statements)

References 21 publications

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“…Dramatic alterations in the infant visual system were found with transient VEPs elicited by flashes of light (Dustman & Beck, 1966, 1969Blom, Barth & Visser, 1980) and by abrupt changes in spatial patterns (Marg, Freeman, Peltzman & Goldstein, 1976;Spekreijse, 1978;Sokol & Jones, 1979;Shaw & Cant, 1981;De Vries-Khoe & Spekreijse, 1982;Allison, Wood & Goff, 1983;Moskowitz & Sokol, 1983). Similar developmental effects were observed in steady-state VEPs (Sokol & Dobson, 1976;Harris, Atkinson & Braddick, 1976;Atkinson, Braddick & French, 1979;Moskowitz & Sokol, 1980;Fiorentini, Pirchio & Spinelli, 1983) and in swept-parameter VEPs (Norcia &Tyler, 1985a, 1985bNorcia, Tyler & Allen, 1986;Norcia, Tyler & Hamer, 1988;Norcia, Tyler, Hamer & Wesemann, 1989;Gottlob, Fendick, Guo, Zubcov, Odom & Reinecke, 1990;Norcia, Tyler & Hamer, 1990;Zemon, Hartmann, Gordon & Priinte, 1993).…”

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confidence: 99%

Contrast-dependent responses in the human visual system: Childhood through adulthood

Zemon

Eisner

Gordon

et al. 1995

International Journal of Neuroscience

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Visual evoked potentials (VEPs) to temporal modulation of spatial patterns, recorded from humans ranging in age from 4-42 years, demonstrated that contrast-dependent responses exist in early childhood and change dramatically throughout childhood. Bright or dark isolated-check stimuli were used to emphasize contributions from ON or OFF pathways to the VEP. (ON and OFF pathways constitute one major pair of parallel subsystems, which process brightness [positive-contrast] and darkness [negative-contrast] information, respectively.) The developmental effects observed for each pathway were similar in magnitude and time course, suggesting maturation of a common physiological mechanism dependent on spatial contrast. Children's responses were more variable and larger than those of adults, and exhibited a relative phase lag. In addition, we recorded transient VEPs to a conventional contrast-reversing checkerboard pattern. The latency of the major positive wave (P100) was found to decrease, while the latency of the initial positive wave (P60) was found to increase, with increasing age. We propose a vector-summation model, which posits a relative decrease in cortical excitation with increasing age, to explain our major findings.

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confidence: 99%

Contrast-dependent responses in the human visual system: Childhood through adulthood

Zemon

Eisner

Gordon

et al. 1995

International Journal of Neuroscience

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“…This altered pattern may have been the result of brain edema, subarachnoid hemorrhage and slowed circulation [M eyer et al, 1970] . Alternatively it may have been the result of interruption of interoccipital connections traversing the splenium [Vaughan and G ross, 1969], von Monakow's 'diaschisis' [Troost and N e w to n , 1974;von M onakow, 1914].…”

Section: Discussionmentioning

confidence: 99%

Electrophysiological Parameters in the Evaluation of Occipital Apoplexy

Feinsod¹,

Wf²,

Wb³

et al. 1975

Eur Neurol

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Visual evoked responses (VER) in four cases of occipital apoplexy supplemented perimetric diagnosis with new electrophysiologic parameters. These included diagnosis of (1) optic radiation involvement by delay in the initial VER component; (2) stirate cortical involvement by obliteration of the initial and late VER components; (3) suprastriate involvement by selective loss of the late VER components, and (4) recovery at one or more of the above levels in the visual process by follow-up examination.

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“…Subnormal amplitudes and length ened latency of the primary potential point to a defect in occipital func tion. However, unequal VEPS obtained by pairs of electrodes placed at equal distances from the median line above the two occipital cortices were found to point to lesions in one occipital lobe which result in a homonymous field defect [8,14,16,17,22], In experimental studies in monkeys following ablation of one occipital lobe [9,30], as well as in man after surgical removal of one occipital lobe [10], responses from the damaged area were absent or at best very small. In case of severe occipital lobe injury [12,19] or occipital blindness of vascular origin [17], preserved VEPs, even of abnormal shape and subnormal ampli tude, point to a favorable prognosis of progressive recovery of visual function.…”

Section: Discussionmentioning

confidence: 99%

Prognostic Value of Visual Evoked Potentials in Occipital Blindness following Basilar Artery Occlusion

Abraham¹,

Melamed²,

Lavy³

1975

Stereotact Funct Neurosurg

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Three patients suffering from sudden occipital blindness following basilar artery occlusion underwent electroretinography and visual evoked potential (VEP) examinations. The VEPs performed early in those blind patients and repeated later seem to be of prognostic value. Responses of normal shape and amplitude after monocular and binocular stimulation were followed by complete recovery of vision. Unequal and subnormal VEPs obtained following monocular stimulation, and even smaller responses reached after binocular stimulation, accompanied permanent unilateral occipital damage resulting in homonymous hemianopsia. Lack of VEP was proved to be a preceding sign of permanent blindness.

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Cortical responses to light in unanesthetized monkeys and their alteration by visual system lesions

Cited by 48 publications

References 21 publications

Contrast-dependent responses in the human visual system: Childhood through adulthood

Contrast-dependent responses in the human visual system: Childhood through adulthood

Electrophysiological Parameters in the Evaluation of Occipital Apoplexy

Prognostic Value of Visual Evoked Potentials in Occipital Blindness following Basilar Artery Occlusion

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