scholarly journals Effects of chronic alcoholism in the sensitivity to luminance contrast in vertical sinusoidal gratings

2016 ◽  
Vol 29 (1) ◽  
Author(s):  
Éllen Dias Nicácio da Cruz ◽  
Michael Jackson Oliveira de Andrade ◽  
Melyssa Kellyane Cavalcanti-Gaudino ◽  
Renata Maria Toscano Barreto Lyra Nogueira ◽  
Natanael Antonio dos Santos
Keyword(s):  
Chronic Alcoholism ◽  
Luminance Contrast ◽  
Sinusoidal Gratings

From spatial frequency contrast to edge preponderance: the differential modulation of early visual evoked potentials by natural scene stimuli

2011 ◽  
Vol 28 (3) ◽  
pp. 221-237 ◽  
Author(s):  
BRUCE C. HANSEN ◽  
THEODORE JACQUES ◽  
AARON P. JOHNSON ◽  
DAVE ELLEMBERG
Keyword(s):  
Spatial Frequency ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Luminance Contrast ◽  
Systematic Investigation ◽  
Natural Scenes ◽  
Natural Scene ◽  
Sinusoidal Gratings ◽  
Edge Content ◽  
Visual Evoked

AbstractThe contrast response function of early visual evoked potentials elicited by sinusoidal gratings is known to exhibit characteristic potentials closely associated with the processes of parvocellular and magnocellular pathways. Specifically, the N1 component has been linked with parvocellular processes, while the P1 component has been linked with magnocellular processes. However, little is known regarding the response properties of the N1 and P1 components during the processing and encoding of complex (i.e., broadband) stimuli such as natural scenes. Here, we examine how established physical characteristics of natural scene imagery modulate the N1 and P1 components in humans by providing a systematic investigation of component modulation as visual stimuli are gradually built up from simple sinusoidal gratings to highly complex natural scene imagery. The results suggest that the relative dominance in signal output of the N1 and P1 components is dependent on spatial frequency (SF) luminance contrast for simple stimuli up to natural scene imagery possessing few edges. However, such a dependency shifts to a dominant N1 signal for natural scenes possessing abundant edge content and operates independently of SF luminance contrast.

scholarly journals Effects of luminance contrast and phase difference on motion assimilation for sinusoidal gratings

1995 ◽  
Vol 35 (16) ◽  
pp. 2277-2286 ◽  
Author(s):  
Yoshio Ohtani ◽  
Keisuke Ido ◽  
Yoshimichi Ejima
Keyword(s):  
Phase Difference ◽  
Luminance Contrast ◽  
Sinusoidal Gratings

Virus-Like Hepatic Cell Particles in Patients with Chronic Alcoholism

1963 ◽  
Vol 44 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Yutaka Kikkawa ◽  
Boris Gueft
Keyword(s):  
Chronic Alcoholism ◽  
Hepatic Cell

Chronic Alcoholism Decreases Polyunsaturated Fatty Acid Levels in Human Plasma, Erythrocytes, and Platelets – Influence of Chronic Liver Disease

1997 ◽  
Vol 78 (02) ◽  
pp. 808-812 ◽  
Author(s):  
María-Luisa Pita ◽  
José-María Rubio ◽  
María-Luisa Murillo ◽  
Olimpia Carreras ◽  
Mariá-José Delgado
Keyword(s):  
Fatty Acid ◽  
Liver Disease ◽  
Chronic Liver Disease ◽  
Chronic Alcoholism ◽  
Chronic Liver ◽  
Chronic Ethanol ◽  
Ethanol Ingestion ◽  
Control Group ◽  
Docosatetraenoic Acid ◽  
Long Chain

SummaryThe effect of chronic ethanol ingestion on fatty acid composition of plasma, erythrocyte and platelet phospholipids and on plasma 6-keto-PGF1α was studied. Two groups of alcoholic subjects, one of them with chronic liver disease, were studied and compared to a control group of healthy subjects. Linoleic acid was not affected by alcoholism but its larger metabolites arachidonic acid (20:4n6) and docosatetraenoic acid (22: 4n6) tended to be lower in erythrocytes and platelets of both groups of alcoholic patients; the decrease was more marked in the presence of chronic liver disease. Docosahexaenoic acid (22:6n3) was markedly decreased in plasma, erythrocytes and platelets obtained from alcoholic patients with chronic liver disease. Plasma levels of 6-keto-PGF1α, a metabolite of prostacyclin (PGI2), remained unchanged. We conclude that chronic ethanol ingestion induces important changes in long-chain polyunsaturated fatty acids, mainly in platelets, and that these changes are exacerbated when patients suffer from chronic liver disease.

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