Psychophysical Forced Choice Method
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Organic solvent exposure and contrast sensitivity: comparing men and women
The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity
Braz J Med Biol Res. Publicado em: 11/01/2018
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2. Effects of chronic alcoholism in the sensitivity to luminance contrast in vertical sinusoidal gratings
Abstract The aim of this study was to measure visual contrast sensitivity (CS) of luminance using vertical sinusoidal gratings with spatial frequencies of 0.6, 2.5, 5.0 and 20.0 cycles per degree of visual angle in chronic alcoholics in abstinence period. The participants were 20 volunteers (26–59 years of age) divided into two groups: the study group (SG)
Psicol. Reflex. Crit.. Publicado em: 20/06/2016
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3. Early malnutrition decreases contrast sensitivity to circular concentric gratings
Early malnutrition refers to inadequate nutrition during the critical period of nervous system development followed by nutritional recovery, resulting in a short stature according to age but normal weight according to short stature. We measured the effects of early malnutrition on contrast sensitivity (CS) to concentric circular gratings in 18 children of bo
Psychol. Neurosci.. Publicado em: 2012-06
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4. Visual contrast sensitivity in tonic-clonic epileptic patients
We measured the effects of epilepsy on visual contrast sensitivity to linear and vertical sine-wave gratings. Sixteen female adults, aged 21 to 50 years, comprised the sample in this study, including eight adults with generalized tonic-clonic seizure-type epilepsy and eight age-matched controls without epilepsy. Contrast threshold was measured using a tempor
Psychology & Neuroscience. Publicado em: 2011-06
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5. A novel polar-based human face recognition computational model
Motivated by a recently proposed biologically inspired face recognition approach, we investigated the relation between human behavior and a computational model based on Fourier-Bessel (FB) spatial patterns. We measured human recognition performance of FB filtered face images using an 8-alternative forced-choice method. Test stimuli were generated by converti
Brazilian Journal of Medical and Biological Research. Publicado em: 2009-07
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6. Contrast sensitivity function of sine-wave gratings in children with acute malnutrition
The aim of this study was to determine the contrast sensitivity curves of sine-wave gratings with spatial frequencies of 0.25, 1.0, 2.0 and 8.0 cycles per degree (cpd) of visual angle in 16 female subjects aged 7 to 9 years old, eight well-nourished and eight with acute protein-energy malnutrition (PEM). All participants had normal visual acuity and were fre
Psychology & Neuroscience. Publicado em: 2009-06
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7. Caracterização da percepção visual em crianças e adolescentes com epilepsia: aspectos cognitivos e sociais / Characterization of the visual perception in children and adolescents with epilepsy: cognitive and social aspects
A epilepsia é um distúrbio cerebral caracterizado pela predisposição persistente do cérebro para gerar crises epilépticas e pelas conseqüências neurobiológicas, cognitivas, psicológicas e sociais desta condição. Algumas pesquisas demonstram que distúrbios visuais são bastante freqüentes em pessoas com epilepsia. Nestes termos, o objetivo deste
Publicado em: 2009
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8. Mesopic radial frequency contrast sensitivity function for young and older adults
The objective of the present study was to determine contrast sensitivity curves of concentric circular patterns with radial frequencies of 0.25, 0.5, 1.0, 2.0, and 4.0 cycles per degree in young and older adult volunteers. These parameters were also compared with sensitivity contrasts for sine-wave gratings. All participants had normal acuity vision and were
Brazilian Journal of Medical and Biological Research. Publicado em: 2006-06
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9. Comparison of angular frequency contrast sensitivity in young and older adults
The aim of the present study was to measure contrast sensitivity curves for angular frequencies in the range between 2 and 96 cycles/360º in older human adult volunteers and to compare these measurements with the more usual contrast sensitivity functions for sine-wave gratings. All subjects were free of identifiable ocular disease and had normal acuity. We
Brazilian Journal of Medical and Biological Research. Publicado em: 2004-03
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10. A comparison of two methods for measuring thermal thresholds in diabetic neuropathy.
Thermal thresholds can be measured psychophysically using either the method of limits or a forced-choice method. We have compared the two methods in 367 diabetic patients, 128 with symptomatic neuropathy. The Sensortek method was chosen for the forced-choice device, the Somedic modification of the Marstock method for a method of limits. Cooling and heat pain
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11. An improved automated method for the measurement of thermal thresholds. 1. Normal subjects.
Clinical tests of thermal sensation are poorly quantified and not strictly modality specific. Previous automated thermal testing systems have had limited usefulness with high intra-and inter-individual variability. This paper describes an automated thermal system (Glasgow system) which is an extensive modification of previous techniques to answer these criti