Search results for " EXPERIMENTAL"
showing 10 items of 3530 documents
The effect of spherical aberration on visual performance and refractive state for stimuli and tasks typical of night viewing
2018
Purpose: The aim of this work was to examine the impact of Seidel spherical aberration (SA) on optimum refractive state for detecting and discriminating small bright lights on a dark background. Methods: An adaptive-optics system was used to correct ocular aberrations of cyclopleged eyes and then systematically introduce five levels of Seidel SA for a 7-mm diameter pupil: 0, ± 0.18, and ± 0.36 diopters (D) mm−2. For each level of SA, subjects were required to detect one or resolve two points of light (0.54 arc min diameter) on a dark background. Refractive error was measured by adjusting stimulus vergence to minimize detection and resolution thresholds. Two other novel focusing tasks for si…
CONFAMI Study: Effects of home confinement during the COVID19 epidemic on the lives of children and their families
2021
The aim of this study is to understand the changes within families during confinement motivated by the COVID-19 pandemic and to explore the psycho-emotional experiences of children and their parents in this new situation. Confinement necessarily induced significant changes in daily family routines, particularly for work, education, leisure and social activities. In the more vulnerable pediatric population, several authors have warned of the need to consider the impact of lockdown measures during COVID-19 on the psychological impact and well-being.This is an anonymous online survey with methodology combining quantitative and qualitative analyses. The questions targeted several themes such as…
The impact of isolated lesions on white-matter fiber tracts in multiple sclerosis patients
2015
Infratentorial lesions have been assigned an equivalent weighting to supratentorial plaques in the new McDonald criteria for diagnosing multiple sclerosis. Moreover, their presence has been shown to have prognostic value for disability. However, their spatial distribution and impact on network damage is not well understood. As a preliminary step in this study, we mapped the overall infratentorial lesion pattern in relapsing–remitting multiple sclerosis patients (N = 317) using MRI, finding the pons (lesion density, 14.25/cm3) and peduncles (13.38/cm3) to be predilection sites for infratentorial lesions. Based on these results, 118 fiber bundles from 15 healthy controls and a subgroup of 23 …
Blocking by word frequency and neighborhood density in visual word recognition: A task-specific response criteria account
2004
International audience; Effects of blocking words by frequency class (high vs. low) and neighborhood density (high vs. low) were examined in two experiments using progressive demasking and lexical decision tasks. The aim was to examine the predictions of a task-specific response criteria account of list-blocking effects. Distinct patterns of blocking effects were obtained in the two tasks. In the progressive demasking task, a pure-list disadvantage was obtained to low frequency-high density words, whereas high frequency-low density produced a trend toward a pure-list advantage. In lexical decision, high-frequency words showed a pure-list advantage that was strongest in high-density words, w…
Functional connectivity of major depression disorder using ongoing EEG during music perception
2020
Abstract Objective The functional connectivity (FC) of major depression disorder (MDD) has not been well studied under naturalistic and continuous stimuli conditions. In this study, we investigated the frequency-specific FC of MDD patients exposed to conditions of music perception using ongoing electroencephalogram (EEG). Methods First, we applied the phase lag index (PLI) method to calculate the connectivity matrices and graph theory-based methods to measure the topology of brain networks across different frequency bands. Then, classification methods were adopted to identify the most discriminate frequency band for the diagnosis of MDD. Results During music perception, MDD patients exhibit…
Olfactory Event-Related Potentials Reflect Individual Differences in Odor Valence Perception
2006
Investigating the neural substrates of perceived quality in olfaction using different odorants is intrinsically difficult. By utilizing individual differences in perceived quality of the odor of androstenone, we obtained a continuum of individual differences in rated valence of the same stimulus allowing investigations of its manifestation in the olfactory event-related potentials (ERPs). In an initial group consisting of 43 individuals that were screened for their verbal descriptors and sensitivity for the odor of androstenone, 22 normosmic volunteers were chosen forming 2 distinct groups with regard to verbal labels (‘‘body odor'' and ‘‘nonbody odor'') for androstenone while maintaining c…
Effects of panel experience on olfactory memory performance: influence of stimuly familiarity and labeling ability of subjects
1996
This work attempted to define the impact of panel experience on olfactory memory performance by comparing scores in an odor recognition task obtained from a highly trained descriptive panel (17 subjects) and a naive one (33 subjects with no experience in sensory analysis). During the inspection phase, 16 odorants were presented monadically to subjects for familiarity rating and a written description. The recognition session was planned 7 days later with 32 odorants (including the 16 of the target set). Subjects also described the odor of the stimuli. The memory performance of each panel was estimated by the mean value of individual d' (index of detectability). Training of the descriptive pa…
Ski Boots Do Not Impair Standing Balance by Restricting Ankle-Joint Mobility.
2018
Objective: This study was undertaken in order to provide new insight into sensorimotor control of posture when wearing high-shaft (HS) boots as ski boots. Background: Previous studies into the effects of HS boots on postural control have produced controversial results. Some studies reported postural control impairments with ski boots in bipedal postural tasks due to ankle movement restrictions without quantifying the actual restrictive effect of these boots and specifying the adaptations of the postural control system. Method: Eighteen young healthy subjects took part in the experiment. Bilateral postural control was assessed on stable and unstable surfaces, while standing barefoot or weari…
Improvement of phonemic fluency following leftward prism adaptation.
2021
AbstractAnatomo functional studies of prism adaptation (PA) have been shown to modulate a brain frontal-parieto-temporal network, increasing activation of this network in the hemisphere ipsilateral to the side of prism deviation. This effect raises the hypothesis that left prism adaptation, modulating frontal areas of the left hemisphere, could modify subjects’ performance on linguistic tasks that map on those areas. To test this hypothesis, 51 healthy subjects participated in experiments in which leftward or rightward prism adaptation were applied before the execution of a phonemic fluency task, i.e., a task with strict left hemispheric lateralization onto frontal areas. Results showed tha…
Does Formal Musical Structure Affect Perception of Musical Expressiveness?
1996
The aim of the study was to assess the effect of systematic modifications in global musical structures on perceived expressiveness. Recorded performances of piano pieces of Bach, Mozart and Schonberg were segmented into short chunks of six seconds in average. These chunks were linked either in a forward order (Original version) or in a backward order (Inverted version). In the inverted version, the formal global structure of the pieces was destroyed, but the superficial features and the local structures inside the chunks were unaltered. Forty non-musician subjects were required to rate the musical expressiveness of these pieces on 29 semantic scales. Half listened to the three original ver…