Search results for " Experimental"

Detrimental noise effects on brain's speech functions.

2009

Background noise has become part of our everyday life in modern societies. Its presence affects both the ability to concentrate and communicate. Some individuals, like children, the elderly, and non-native speakers have pronounced problems in noisy environments. Here we review evidence suggesting that background noise has both transient and Sustained detrimental effects on central speech processing. Studies on the effects of noise on neural processes have demonstrated hemispheric reorganization in speech processing in adult individuals during background noise. During noise, the well-known left hemisphere dominance in speech discrimination became right hemisphere preponderant. Furthermore, l…

Motor Resonance Mechanisms during Action Imitation in Depression

2018

Objectives Major depressive disorder has been associated with impairments in social cognition. However, studies exploring the processing of social information focused on facial discrimination. The aim of this study was to better characterize the sensorimotor mechanisms underlying motor resonance in depressed patients. Method Twenty-three right-handed patients meeting DSM-IV criteria for unipolar depression were compared to 14 matched healthy controls. In a simple imitation paradigm, the kinematic features of movements in natural condition were compared to those of motions performed after the observation of a moving dot. Reaction time and pointing velocity were considered to evaluate if the …

2019

The effect of sensory experience on hemispheric specialisation for language production is not well understood. Children born deaf, including those who have cochlear implants, have drastically different perceptual experiences of language than their hearing peers. Using functional transcranial Doppler sonography (fTCD), we measured lateralisation during language production in a heterogeneous group of 19 deaf children and in 19 hearing children, matched on language ability. In children born deaf, we observed significant left lateralisation during language production (British Sign Language, spoken English, or a combination of languages). There was no difference in the strength of lateralisation…

The role of insulin-like growth factor II in the malignant transformation of rat liver oval cells

1997

Oval cells are small nonparenchymal epithelial cells that first appear in the periportal areas of the liver and thereafter invade the whole parenchyma when mice or rats are exposed to a variety of chemical carcinogens. In the present study we have analyzed the expression of insulin-like growth factor II (IGF II) in the recently established oval cell line OC/CDE 22 and its malignantly transformed counterpart (the M22 cells) and the biological consequences of the constitutive expression of IGF II in oval cells. OC/CDE 22 cells do not express the above-mentioned growth factor, whereas the M22 cells do and addition of a neutralizing anti-IGF II antibody to M22 cells resulted in an almost comple…

Thermal increase in the oral mucosa and in the jawbone during Nd:YAG laser applications. Ex vivo study

2012

Objective: Literature reports bactericidal and biostimulant effects for Nd:YAG laser procedures on bone and oral mucosa but the possible overheating can cause damage to anatomical structures. The aim of the study is the evaluation of thermal increase in different levels of oral tissues: mucosa, periosteum and bone during defocused application of Nd:YAG laser at different parameters. Study Design: Superficial thermal evaluation was performed in pig jaws with a thermal camera device; deep thermal evaluation was realized by 4 thermocouples placed at a subperiosteal level and at 1,2 and 4 mm depth in the jaw bone. Laser applications of 1 minute were performed 5 times (with a pause of 1 minute) …

2019

OBJECTIVE With a combination of different sympathetic tests, we aimed to elucidate whether impairment of sympathetic function in Parkinson's disease (PD) is the consequence of a central or peripheral efferent dysfunction. METHODS Thirty-five patients with early-to-intermediate PD (median age: 63 years; IQR: 57-67 years; disease duration 1-9 years, 15 women) and 20 age- and sex-matched healthy controls (median age: 64.5 years; IQR: 58-68 years; 10 women) were recruited. Autonomic testing was performed in two subgroups and included the assessment of resting cardiovascular parameters, postprandial hypotension (PPH), orthostatic hypotension (OH), and vasoconstriction induced by intradermal micr…

Deviance detection in sound frequency in simple and complex sounds in urethane-anesthetized rats

2019

Mismatch negativity (MMN), which is an electrophysiological response demonstrated in humans and animals, reflects memory-based deviance detection in a series of sounds. However, only a few studies on rodents have used control conditions that were sufficient in eliminating confounding factors that could also explain differential responses to deviant sounds. Furthermore, it is unclear if change detection occurs similarly for sinusoidal and complex sounds. In this study, we investigated frequency change detection in urethane-anesthetized rats by recording local-field potentials from the dura above the auditory cortex. We studied change detection in sinusoidal and complex sounds in a series of …

2017

This study investigated the role of vection (i.e., a visually induced sense of self-motion), optokinetic nystagmus (OKN), and inadvertent head movements in visually induced motion sickness (VIMS), evoked by yaw rotation of the visual surround. These three elements have all been proposed as contributing factors in VIMS, as they can be linked to different motion sickness theories. However, a full understanding of the role of each factor is still lacking because independent manipulation has proven difficult in the past. We adopted an integrative approach to the problem by obtaining measures of potentially relevant parameters in four experimental conditions and subsequently combining them in a …

2018

Purpose: There is some controversy whether or not saccades change with age. This cross-sectional study aims to clarify the characteristics of reflexive saccades at various ages to establish a normative cohort in a standardized set-up. Second objective is to investigate the feasibility of saccadometry in daily ophthalmological practice. Methods: One hundred healthy participants aged between 6 and 76 years underwent an ophthalmologic examination and saccadometry, using an infrared video-oculography device, sampling at 220 Hz. The reflexive saccades were evoked in four directions and three target displacements each (5°/15°/30° horizontally and of 5°/10°/20° vertically). Saccadic peak velocity,…

Histochemical changes in kidneys and adrenals of rats made hypertensive by the Goldblatt method.

1958

Histochemical Changes in Kidneys and Adrenals of Rats made Hypertensive by the Goldblatt Method