Search results for "perception."
showing 10 items of 3582 documents
Influence of the luminance level on visual performance with a disposable soft cosmetic tinted contact lens.
2001
The purpose of the present work was to study the effect on visual performance of wearing disposable soft tinted contact lenses for cosmetic purposes. Parameters such as contrast sensitivity (Vistech 6000), colour vision (Farnsworth-Munsell 100-Hue colour test), visual fields (static Goldmann perimetry) and subjective vision (what the wearer feels while wearing the lenses) were studied under different illumination levels in order to check for possible vision losses while wearing these contact lenses at low illumination levels. Sixteen emmetropic subjects were fitted consecutively with seven pairs of different colour lenses (Optima Colors lenses by BauschLomb), and the experimental parameters…
Detection of sound rise time by adults with dyslexia
2005
Low sensitivity to amplitude modulated (AM) sounds is reported to be associated with dyslexia. An important aspect of amplitude modulation cycles are the rise and fall times within the sound. In this study, simplified stimuli equivalent to just one cycle were used and sensitivity to varying rise times was explored. Adult participants with dyslexia or compensated dyslexia and a control group performed a detection task with sound pairs of different rise times. Results showed that the participants with dyslexia differed from the control group in rise time detection and a correlation was found between rise time detection and reading and phonological skills. A subgroup of participants with lower…
Tower of Hanoi and working memory in adult persons with intellectual disability
2001
Persons with intellectual disability (ID) have been found to perform more poorly than their mental age would suggest in the visuo-spatial problem solving task Tower of Hanoi (TOH). Inefficient performance has been assumed to be related to inability to use sophisticated problem solving strategies because of restricted working memory capacity. In the present study, the TOH performance of adult persons with ID was found to be equal to that of fluid-intelligence-matched general children. However, persons with ID violated the rules of the TOH more often, and needed more trials to solve the TOH problems than the children did. Visuo-spatial and executive working memory tasks were significantly con…
Dissociating spatial and letter-based word length effects observed in readers’ eye movement patterns
2011
In previous eye movement research on word length effects, spatial width has been confounded with the number of letters. McDonald (2006) unconfounded these factors by rendering all words in sentences in constant spatial width. In the present study, the Arial font with proportional letter spacing was used for varying the number of letters while equating for spatial width, while the Courier font with monospaced letter spacing was used to measure the contribution of spatial width to the observed word length effect. Number of letters in words affected single fixation duration on target words, whereas words’ spatial width determined fixation locations in words and the probability of skipping a wo…
On methods of access to the structure of social representations: the example of Europe.
2012
espanolEl objetivo de este estudio es identificar la logica detras de una serie de metodos estadisticos utilizados para revelar la estructura de las representaciones sociales. Se solicito a un numero de sujetos (n = 317) responder a la pregunta siguiente: �Para cada categoria de europeo, por favor indique con que otros europeos le gustaria tener contacto�. Los resultados de los analisis de similitud nos llevan a la conclusion de que existe un sesgo etnocentrico, y revelan el factor central de la representacion. La representacion obtenida por el analisis factorial de correspondencias se parece mas a la realidad actual y nos permite entender las divisiones que han estructurado Europa y perman…
Measures of native and non-native rhythm in a quantity language.
2005
The traditional phonetic classification of language rhythm as stress-timed or syllable-timed is attributed to Pike. Recently, two different proposals have been offered for describing the rhythmic structure of languages from acoustic-phonetic measurements. Ramus has suggested a metric based on the proportion of vocalic intervals and the variability ( SD) of consonantal intervals. Grabe has proposed Pairwise Variability Indices (nPVI, rPVI) calculated from the differences in vocalic and consonantal durations between successive syllables. We have calculated both the Ramus and Grabe metrics for Latvian, traditionally considered a syllable rhythm language, and for Latvian as spoken by Russian l…
Does Extra Interletter Spacing Help Text Reading in Skilled Adult Readers?
2016
AbstractA number of experiments have shown that, in skilled adult readers, a small increase in interletter spacing speeds up the process of visual word recognition relative to the default settings (i.e., judge faster than judge). The goal of the present experiment was to examine whether this effect can be generalized to a more ecological scenario: text reading. Each participant read two stories (367 words each) taken from a standardized reading test. The stories were presented with the standard interletter spacing or with a small increase in interletter spacing (+1.2 points to default) in a within-subject design. An eyetracker was used to register the participants’ eye movements. Comprehens…
The German hearing in noise test
2020
The aims of this study were to develop a German Hearing In Noise Test (HINT) using the same methodology as with previous HINT tests; to develop sentence lists for measuring speech reception thresholds (SRTs); and to determine test-retest reliability and norms for measures obtained under headphones.The following steps were followed: develop and record sentences, synthesise masking noise, determine the performance-intensity (PI) function, equalise sentence difficulty in the masking noise. Form sentence lists of equal difficulty. Measure SRTs for normal hearing individuals to determine practice/learning effects, test-retest reliability, and norms.Three groups of adults (median age = 25 years) …
Methodical aspects of perceived exertion rating and its relation to pedalling rate and rotating mass.
1975
Methodical aspects of the relationship between pedalling rate and rotating mass and perceived exertion rating (PER; Borg, 1962) were studied in trained, untrained, and ill subjects in bicycle ergometry. Pedalling rate varied between 40 and 100 rpm, work load steps were 5, 10, 15 and 20 mkp/sec in the healthy subjects, and 2.5, 5, 7.5 and 10 mkp/sec in the patients. PER decreased with increasing pedalling rate in all healthy subjects. In the patients, PER increased moderately at work load of 2.5 mkp/sec, but decreased at higher work loads up to 80 rpm, followed by a slight increase at 100 rpm. Higher mass of the flywheel, studied in 6 trained subjects, lowered the PER insignificantly. In the…
Size invariance in visual number discrimination
1991
This study deals with the observer's ability to discriminate the numerosity of two random dot-patterns irrespective of their relative size. One of these two patterns was a reference one that was always composed of 32 dots randomly distributed within a K x K invisible square window (K = 1.92 degrees). The second one was the test pattern with one of the five magnifications (K = 0.64 degrees, 1.28 degrees, 1.92 degrees, 2.56 degrees, 3.20 degrees) and the relative number of dots varied on 11 levels (N = -15, -12, -9, -6, -3, 0, 3, 6, 9, 12, or 15 dots). The observer's task was to indicate which of the two patterns contained more dots. The results show that the stimulus size, as an irrelevant s…