Influência do Cronotipo e do Horário da Medida na Sensibilidade ao Contraste Visual

Abstract

ResumoEste estudo teve como objetivo avaliar a curva de sensibilidade ao contraste para estímulos de grades senoidais verticais de frequências espaciais de 0,2; 0,6; 1; 3,1; 6,1; 8,8; 13,2 e 15,6 ciclos por grau de ângulo visual; em um ritmo de 24 horas de adultos saudáveis de diferentes cronotipos. Participaram desta pesquisa 18 voluntários do sexo masculino com idade de 19 a 31 anos (M=23,8; DP=3,29 AbstractThis study aimed to evaluate the contrast sensitivity curve for the stimuli of vertical sinusoidal grids with spatial frequencies of .2; .6; 1; 3.1; 6.1; 8.8; 13.2 and 15.6 cycles per degree of visual angle, in a 24-hour rhythm of healthy adults of different chronotypes. This study had 18 participants aged 19 to 31 years (M=23.8; SD=3.29) divided into groups according to the chronotype: Morningness (n=5), Intermediate (n=9) and Moderate Eveningness (n=4). Neuropsychological measures and the Metropsis software were used to evaluate the Contrast Sensitivity Function (CSF). CSF measurements were performed by the psychophysical method of forced choice between two spatial alternatives. Results showed signifi cant changes in the dimensions related to cognitive processing and CSF for morning subjects [F (14; 76303) The study concluded that contrast sensitivity is an important aspect to the study of circadian visual perception, suggesting that the sensorial mechanisms which process visual contrast are directly related to the time and pattern of people's chronotypes.

Daily variation of visual perception of colors: Preliminary studies.

“…The test was performed in a dark room using a dominant eye with a distance of 300 cm from the display. A forced-choice method with four alternatives was used (Andrade et al, 2015), starting at a specific point of the International Commission on Illumination diagram of 1976 (Geller & Hudnell, 1997) and extending to the center of the color space at U′V′ (0.197, 0.469; Costa et al, 2012). Each participant responded with the key control, the orientation of the C stimulus, either by moving it up, down, right or left.…”

“…The other test, Ellipses, is longer than Trivector and determines parameters of three MacAdam ellipses that are along the same line of confusion. The screening of the visual system for these tests makes it possible to check circadian alteration in vision according to the CT of subjects considered healthy (Andrade, Silva, & Santos, 2015).…”

“…The variation of the illuminance discrimination has been carried out in several studies, mainly related to luminance visual contrast (Andrade et al, 2015; Bassi & Powers, 1986; Danilenko, Plisov, Cooper, Wirz-Justice, & Hébert, 2011; Roenneberg, Lotze, & Steinbuchel, 1992; Struck, Rodnitzky, & Dobson, 1990; Tassi, Pellerin, Moessinger, Hoeft, & Muzet, 2000; Tassi & Pins, 1997). However, studies that investigated the circadian mechanisms of color perception are still considered preliminary.…”

Spatial contrast sensitivity: effects of reliability, test–retest repeatability and sample size using the Metropsis software

“…In view of this, the Metropsis software was developed to provide a comprehensive evaluation of the CSF in retinal, cortical and subcortical populations. The Metropsis vision testing has been used in several studies [12,[15][16][17][18][19]. Despite reliable results, the effects of eye dominance, sample size and repeatability of Metropsis have not been studied.…”

Visual function alterations in epilepsy secondary to migraine with aura: A case report.

“…The principles of these tests, the psychophysical method used, and the algorithms used to define the statistical variables are described in detail in other studies (Andrade, Silva, & dos Santos, 2015; dos Santos, Andrade, & Calvo, 2013; Fernandes et al, 2017).…”