Search results for "Visual Perception"

Visual grouping under isoluminant condition: impact of mental fatigue

2016

Instead of selecting arbitrary elements our visual perception prefers only certain grouping of information. There is ample evidence that the visual attention and perception is substantially impaired in the presence of mental fatigue. The question is how visual grouping, which can be considered a bottom-up controlled neuronal gain mechanism, is influenced. The main purpose of our study is to determine the influence of mental fatigue on visual grouping of definite information – color and configuration of stimuli in the psychophysical experiment. Individuals provided subjective data by filling in the questionnaire about their health and general feeling. The objective evidence was obtained in t…

Machinery Failure Approach and Spectral Analysis to Study the Reaction Time Dynamics over Consecutive Visual Stimuli: An Entropy-Based Model.

2020

[EN] The reaction times of individuals over consecutive visual stimuli have been studied using an entropy-based model and a failure machinery approach. The used tools include the fast Fourier transform and a spectral entropy analysis. The results indicate that the reaction times produced by the independently responding individuals to visual stimuli appear to be correlated. The spectral analysis and the entropy of the spectrum yield that there are features of similarity in the response times of each participant and among them. Furthermore, the analysis of the mistakes made by the participants during the reaction time experiments concluded that they follow a behavior which is consistent with …

Are transposition effects specific to letters?

2010

Recent research has consistently shown that pseudowords created by transposing two letters are perceptually similar to their corresponding base words (e.g., jugde–judge). In the framework of the overlap model (Gomez, Ratcliff, & Perea, 2008), this effect is due to a noisy process in the localization of the “objects” (e.g., letters, kana syllables). In the present study, we examine whether this effect is specific to letter strings or whether it also occurs with other “objects” (namely, digits, symbols, and pseudoletters). To that end, we conducted a series of five masked priming experiments using the same–different task. Results showed robust effects of transposition for all objects, ex…

Study and Comparison of Surface Roughness Measurements

2014

Journées du Groupe de Travail en Modélisation Géométrique (GTMG'14), Lyon; This survey paper focus on recent researches whose goal is to optimize treatments on 3D meshes, thanks to a study of their surface features, and more precisely their roughness and saliency. Applications like watermarking or lossy compression can benefit from a precise roughness detection, to better hide the watermarks or quantize coarsely these areas, without altering visually the shape. Despite investigations on scale dependence leading to multi-scale approaches, an accurate roughness or pattern characterization is still lacking, but challenging for those treatments. We think there is still room for investigations t…

Comparison of sensory visual properties of food products in real and virtual conditions

2018

International audience; As Virtual Reality usages expand, as professional tools in one hand and as gaming devices in another hand, the use of these technologies for consumer science and sensory science is more and more interesting to be investigated. Before using Virtual Reality to evaluate new products, it seems necessary to check the similarities and differences of the visual attributes of products in real and in virtual. All the experiments were conducted with Unity software and HTC Vive Helmet. First, we designed virtual sensory booths, similar to the booths of AgroParisTech sensory Lab. Then, we choose a set of real products (cookies from the market) and digitalize them. At last, virtu…

Visual exploration of face and facial expression in infancy: A qualitative approach of cognitive and social development

2016

International audience; This article proposes a methodological consideration for the use of "head free" eye-tracking systems, which allowed to extend this technique to the study of infant skills. It explores how the technological developments enable a more qualitative approach, which offers the possibility of considering "how" in addition to "how long" the infant looks at a visual scene, especially the scene of the face.

PICTURES, GESTURES AND DISCOURSES: A CASE STUDY WITH KINDERGARTEN STUDENTS DISCOVERING LEGO BRICKS

The awareness of the importance to look, through a mathematical lens, to the children drawings, gestures and discourses, considering them as diagnostic tools for the mathematics competences, stays at the base of this contribution. It discusses a didactic experience conducted in a Kindergarten (students 5 or 6 years old) in which we asked children to represent and discus a Lego block with a drawing and speech, observed from different prospective. The discussed results seem to us interesting both for researchers in Mathematics Education and for Kindergarten teachers who want to deepen the role of drawing and gestures as an expressive and diagnostic forms to analyze students’ knowledge, abilit…

Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots

2015

Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits ( Parus major ) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, wi…

Interpersonal Distance in the SARS-CoV-2 Crisis

2020

Background Mandatory rules for social distancing to curb the SARS-CoV-2 pandemic require individuals to maintain a critical interpersonal distance above 1.5 m. However, this contradicts our natural preference, which is closer to 1 m for non-intimate encounters, for example, when asking a stranger for directions. Objective This review addresses how humans typically regulate interpersonal distances, in order to highlight the challenges of enforcing atypically large interpersonal distances. Method To understand the challenges posed by social distancing requirements, we integrate relevant contributions from visual perception, social perception, and human factors. Results To date, research on pr…

2020

It has been suggested that early cry parameters are connected to later cognitive abilities. The present study is the first to investigate whether the acoustic features of infant cry are associated with cognitive development already during the first year, as measured by oculomotor orienting and attention disengagement. Cry sounds for acoustic analyses (fundamental frequency; F0) were recorded in two neonatal cohorts at the age of 0-8 days (Tampere, Finland) or at 6 weeks (Cape Town, South Africa). Eye tracking was used to measure oculomotor orienting to peripheral visual stimuli and attention disengagement from central stimuli at 8 months (Tampere) or at 6 months (Cape Town) of age. Only a m…