Search results for "visual"

Transformaciones en el ecosistema mediático y nuevas pautas de regulación administrativa del audiovisual

2007

La regulació de l'audiovisual al nostre país, com a la resta de països del nostre entorn jurídic, s'ha basat històricament en la definició d'aquestes activitats com de servei públic. A partir d'aquesta definició, s'ha conformat el model d'actuació de les administracions públiques sobre el sector. L'erosió progressiva de la idea de servei públic, la seua desaparició en part del sector i l'emergència de noves possibilitats tecnolò- giques, així com la importància creixent d'àmbits on la comunicació s'ordena a partir de les llibertats d'expressió, d'una banda, i de la llibertat d'empresa, de l'altra, obliguen a replantejar la forma i l'orientació de la intervenció pública sobre el sector.

The impact of a concurrent motor task on auditory and visual temporal discrimination tasks

2016

Previous studies have shown the presence of an interference effect on temporal perception when participants are required to simultaneously execute a nontemporal task. Such interference likely has an attentional source. In the present work, a temporal discrimination task was performed alone or together with a self-paced finger-tapping task used as concurrent, nontemporal task. Temporal durations were presented in either the visual or the auditory modality, and two standard durations (500 and 1, 500 ms) were used. For each experimental condition, the participant’s threshold was estimated and analyzed. The mean Weber fraction was higher in the visual than in the auditory modality, but only for…

Enhancing Visuomotor Adaptation by Reducing Error Signals: Single-step (Aware) versus Multiple-step (Unaware) Exposure to Wedge Prisms

2007

Abstract Neglect patients exhibit both a lack of awareness for the spatial distortions imposed during visuomanual prism adaptation procedures, and exaggerated postadaptation negative after-effects. To better understand this unexpected adaptive capacity in brain-lesioned patients, we investigated the contribution of awareness for the optical shift to the development of prism adaptation. The lack of awareness found in neglect was simulated in a multiple-step group where healthy subjects remained unaware of the optical deviation because of its progressive stepwise increase from 2° to 10°. We contrasted this method with the classical single-step group in which subjects were aware of the visual …

Neural Processing of Congruent and Incongruent Audiovisual Speech in School-Age Children and Adults

2017

Audiovisual speech perception in children with developmental language disorder in degraded listening conditions.

2013

Purpose The effect of the signal-to-noise ratio (SNR) on the perception of audiovisual speech in children with and without developmental language disorder (DLD) was investigated by varying the noise level and the sound intensity of acoustic speech. The main hypotheses were that the McGurk effect (in which incongruent visual speech alters the auditory speech percept) would be weaker for children with DLD than for controls and that it would get stronger with decreasing SNR in both groups. Method The participants were 8-year-old children with DLD and a sample of children with normal language development. In the McGurk stimuli, the consonant uttered by the voice differed from that articulated …

Modifying auditory perception with prisms? Aftereffects of prism adaptation on a wide auditory spectrum in musicians and nonmusicians

2021

Prism adaptation consists of pointing to visual targets while wearing prisms that shift the visual field laterally. The aftereffects are not restricted to sensorimotor level but extend to spatial cognition. There is a link between spatial representation and auditory frequency, with an association of low frequencies on the left side and high frequencies on the right side of space. The present study aimed first at evaluating the representation of auditory frequencies on a wide range of frequencies in musicians and nonmusicians. We used the ‘auditory interval bisection judgment’ within three auditory intervals. The results showed a pseudoneglect behavior in pretest in musicians and nonmusician…

Prior Precision Modulates the Minimization of Auditory Prediction Error

2019

International audience; The predictive coding model of perception proposes that successful representation of the perceptual world depends upon canceling out the discrepancy between prediction and sensory input (i.e., prediction error). Recent studies further suggest a distinction to be made between prediction error triggered by non-predicted stimuli of different prior precision (i.e., inverse variance). However, it is not fully understood how prediction error with different precision levels is minimized in the predictive process. Here, we conducted a magnetoencephalography (MEG) experiment which orthogonally manipulated prime-probe relation (for contextual precision) and stimulus repetition…

Data from: Individual differences in selective attention predict speech identification at a cocktail party

2017

Listeners with normal hearing show considerable individual differences in speech understanding when competing speakers are present, as in a crowded restaurant. Here, we show that one source of this variance are individual differences in the ability to focus selective attention on a target stimulus in the presence of distractors. In 50 young normal-hearing listeners, the performance in tasks measuring auditory and visual selective attention was associated with sentence identification in the presence of spatially separated competing speakers. Together, the measures of selective attention explained a similar proportion of variance as the binaural sensitivity for the acoustic temporal fine stru…

How is Visual Recognition Entrained by Auditory Background Rhythms?

2014

AbstractRecent studies have reported that the oscillations of auditory attention entrained by a background rhythmic sequence can influence performance in visual recognition tasks. We have designed an experimental paradigm in which a visual item (either a bisyllabic word or a familiar face) is displayed on screen in two consecutive parts while a musical rhythm is played in the background. Depending on the timing conditions, the first or the second part of the item could be presented either in-synchrony or out-of-synchrony with the beats of the auditory rhythm. In a first series of experiments, participants performed a lexical decision task on bisyllabic 5-letter strings. Results show that wh…

The growth of oxide platelets on nickel in pure oxygen. II. Surface analyses and growth mechanism

1993

The structural properties of NiO platelets emerging from a primary oxide layer by oxidation of pretreated nickels in pure oxygen between 650 and 800° C have been investigated in relation with the initial metallic layers and the primary oxide. Surface composition and segregation of impurities were also studied by X-ray photoelectron spectroscopy and Auger electron spectroscopy. Textural properties and structural orientation of both the primary oxide layer and the platelets were analyzed by X-ray diffraction and transmission electron microscopy. Platelets grew along {111} planes, leading to elliptical or semicircular bicrystals. The driving force for the present type of growth originates from…