Search results for "Healthy subject"
showing 10 items of 195 documents
Modulating memory performance in healthy subjects with Trancranial Direct Current Stimulation over the right dorsolateral prefrontal cortex
2015
Objective: The role of the Dorsolateral Prefrontal Cortex (DLPFC) in recognition memory has been well documented in lesion, neuroimaging and repetitive Transcranial Magnetic Stimulation (rTMS) studies. The aim of the present study was to investigate the effects of transcranial Direct Current Stimulation (tDCS) over the left and the right DLPFC during the delay interval of a non-verbal recognition memory task. Method: 36 right-handed young healthy subjects participated in the study. The experimental task was an Italian version of Recognition Memory Test for unknown faces. Study included two experiments: in a first experiment, each subject underwent one session of sham tDCS and one session of…
Recognition memory and prefrontal cortex: Dissociating recollection and familiarity processes using rTMS
2008
Recognition memory can be supported by both the assessment of the familiarity of an item and by the recollection of the context in which an item was encountered. The neural substrates of these memory processes are controversial. To address these issues we applied repetitive transcranial magnetic stimulation (rTMS) over the right and left dorsolateral prefrontal cortex (DLPFC) of healthy subjects performing a remember/know task. rTMS disrupted familiarity judgments when applied before encoding of stimuli over both right and left DLPFC. rTMS disrupted recollection when applied before encoding of stimuli over the right DLPFC. These findings suggest that the DLPFC plays a critical role in recog…
Excitability regulation in the dorsomedial prefrontal cortex during sustained instructed fear responses: a TMS-EEG study
2018
AbstractThreat detection is essential for protecting individuals from adverse situations, in which a network of amygdala, limbic regions and dorsomedial prefrontal cortex (dmPFC) regions are involved in fear processing. Excitability regulation in the dmPFC might be crucial for fear processing, while abnormal patterns could lead to mental illness. Notwithstanding, non-invasive paradigms to measure excitability regulation during fear processing in humans are missing. To address this challenge we adapted an approach for excitability characterization, combining electroencephalography (EEG) and transcranial magnetic stimulation (TMS) over the dmPFC during an instructed fear paradigm, to dynamica…
The effect of paired associative stimulation on fatigue resistance
2015
Paired associative stimulation (PAS) is a non-invasive stimulation method developed to induce bidirectional changes in the excitability of the cortical projections to the target muscles. However, very few studies have shown an association between changes in motor evoked potentials (MEP) after PAS and behavioral changes in healthy subjects. In the present study we hypothesized that the functional relevance of PAS can be seen during fatiguing exercise, since there is always a central contribution to the development of fatigue. Transcranial magnetic stimulation was applied over the motor cortex to measure changes in the MEPs of the soleus muscle before and after PAS. Furthermore, fatigue resis…
Paired pulse TMS over the right posterior parietal cortex modulates visuospatial perception
2006
Abstract Objective We previously observed a relative contralateral neglect by right parietal single-pulse TMS given 150 ms after visual stimulus presentation. Here we investigated the effects of parietal paired TMS in normal subjects performing a visuospatial task. Methods Thirteen right-handed healthy subjects underwent a line-length judgement task during single-pulse and paired (1, 3, 5, 10 ms ISIs) TMS, delivered on the right parietal cortex 150 ms after visual stimulus. Results Single pulse TMS over the right parietal cortex induced a significant rightward bias compared to the baseline condition. At 1 and 3 ms ISIs, paired-pulse TMS did not show any effect in comparison with single puls…
Assessment of haemophilic arthropathy through balance analysis: a promising tool
2019
[EN] The purpose of this study was to develop a tool able to distinguish between subjects who have haemophilic arthropathy in lower limbs and those who do not by analyzing the centre of pressure displacement. The second objective was to assess the possible different responses of haemophiliacs and healthy subjects by creating a classifier that could distinguish between both groups. Fiftyfour haemophilic patients (28 with and 26 without arthropathy) and 23 healthy subjects took part voluntarily in the study. A force plate was used to measure postural stability. A total of 276 centre of pressure displacement parameters were calculated under different conditions: unipedal/bipedal balance with e…
Bilateral photoplethysmography studies of the leg arterial stenosis.
2005
A newly developed portable multi-channel photoplethysmography (PPG) device has been used for comparative studies of 20 healthy control subjects and 45 patients with diagnosed arterial stenosis in a leg. The peripheral blood pulsations were detected simultaneously at four body sites-the same fingers and toes of both arms and legs. The PPG pulses recorded at the periphery of the stenotic leg, if compared with those of the healthy leg, were much weaker, with delayed arrival as a consequence of increased pulse wave transit time (PWTT) due to higher vascular resistance. The specific PWTT delays for the occluded legs were in the range of 20-80 ms, while in the case of healthy subjects the leg PPG…
Assessment of the Tricuspid Valve Morphology by Transthoracic Real-Time-3D-Echocardiography
2005
Aim: To demonstrate the feasibility of transthoracic three-dimensional real-time echocardiography (3D-TTE) supplemental to routine assessments of the tricuspid valve and to analyze interrater agreement. Methods: Twenty healthy subjects and 74 patients with right ventricular failure were examined with conventional 2D and additionally 3D-TTE (SONOS 7500, Philips, Netherlands). The 3D exams were performed and recorded by one of two raters. The recordings were evaluated offline and independently by both raters for visualization of morphological and functional features of the tricuspid valve according to a subjective 3-point scale. Statistical analyses were performed for interrater agreement and…
Learning Curve and Fatigue Effect of Flicker Defined Form Perimetry
2011
To evaluate the learning curve and fatigue effect of flicker defined form (FDF) perimetry.Prospective cross-sectional study.One hundred forty-one eyes of 75 healthy subjects were included in the study. Every subject was measured 3 times on 3 different days within 3 months. Differences among the tests were analyzed for mean sensitivity (MS), mean deviation (MD), pattern standard deviation (PSD), reliability indices, test duration, and test points5% and0.5% in 75 right eyes on the basis of linear mixed models for repeated measurements. To assess the effect of fatigue, differences of MS, MD, and PSD values between 66 left and right eyes were evaluated regarding alterations between these 3 exam…
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…