Search results for "Healthy subjects"

Neglect-like effects induced by tDCS modulation of posterior parietal cortices in healthy subjects

2011

Background Repetitive transcranial magnetic stimulation (rTMS) over right posterior parietal cortex was shown to induce interference on visuospatial perception in healthy subjects. Transcranial direct current stimulation (tDCS) is another noninvasive brain stimulation technique that works modulating cortical activity. It is applied through easy to use, noncostly, and portable devices. Objective/Hypothesis The aim of the current study was to investigate if the novel approach of “dual” stimulation over parietal cortices compared with the unilateral (right) cathodal one is able to induce greater and/or longer-lasting neglect-like effects in normal subjects performing a computerized visuospatia…

Comparison of tactile sensitivity measured with a new digital esthesiometer (Beam Test) relative to Semmes–Weinstein monofilament analog esthesiometer

2019

The assessment of tactile sensitivity uses many tests, of which monofilaments are considered the best. The aim of this study was to develop a tactile sensitivity test, similar to the monofilament test, which eliminates the error risk related to manipulations by the observer, and to establish a correspondence scale. We studied 29 healthy subjects (18 women and 11 men) with a mean age of 27.8 years. The Semmes-Weinstein monofilament (SWM) analog esthesiometer and a digital beam esthesiometer (DBE) were used. We evaluated the tactile sensitivity threshold on the fingertip of each subject's dominant index using the SWM and the DBE. The DBE test consisted of applying the index against the tip of…

Echocardiographic reference ranges for normal left ventricular layer-specific strain: results from the EACVI NORRE study

2020

Abstract Aims  To obtain the normal range for 2D echocardiographic (2DE) measurements of left ventricular (LV) layer-specific strain from a large group of healthy volunteers of both genders over a wide range of ages. Methods and results  A total of 287 (109 men, mean age: 46 ± 14 years) healthy subjects were enrolled at 22 collaborating institutions of the EACVI Normal Reference Ranges for Echocardiography (NORRE) study. Layer-specific strain was analysed from the apical two-, three-, and four-chamber views using 2DE software. The lowest values of layer-specific strain calculated as ±1.96 standard deviations from the mean were −15.0% in men and −15.6% in women for epicardial strain, −16.8% …

Relation between late potentials and echocardiographically determined left ventricular mass in healthy subjects.

1991

Human papillomavirus is commonly present in psoriatic skin and normal skin samples from healthy subjects

2007

Letter to editor No abstract

Imaging the visual autokinetic illusion with fMRI

2005

During fixation of a stationary, dim light-emitting diode (LED) in complete darkness, a subtle, apparent motion is perceived which is called autokinesis. This autokinetic illusion increases with increasing fixation time. Eleven healthy subjects were examined by fMRI while fixating an LED in darkness for 35 s. BOLD signal changes of the first and the second half of the fixation period were compared. While the stimulus was the same for both periods, perception differed in that autokinesis was more pronounced in the second half. This second half of the period was associated with bilateral activations in the motion-sensitive middle occipito-temporal area known as MT/V5. Our finding suggests tha…

Conditional Self-Entropy and Conditional Joint Transfer Entropy in Heart Period Variability during Graded Postural Challenge.

2015

Self-entropy (SE) and transfer entropy (TE) are widely utilized in biomedical signal processing to assess the information stored into a system and transferred from a source to a destination respectively. The study proposes a more specific definition of the SE, namely the conditional SE (CSE), and a more flexible definition of the TE based on joint TE (JTE), namely the conditional JTE (CJTE), for the analysis of information dynamics in multivariate time series. In a protocol evoking a gradual sympathetic activation and vagal withdrawal proportional to the magnitude of the orthostatic stimulus, such as the graded head-up tilt, we extracted the beat-to-beat spontaneous variability of heart per…

Standardized T2* map of normal human heart in vivo to correct T2* segmental artefacts.

2007

A segmental, multislice, multi-echo T2* MRI approach could be useful in heart iron-overloaded patients to account for heterogeneous iron distribution, demonstrated by histological studies. However, segmental T2* assessment in heart can be affected by the presence of geometrical and susceptibility artefacts, which can act on different segments in different ways. The aim of this study was to assess T2* value distribution in the left ventricle and to develop a correction procedure to compensate for artefactual variations in segmental analysis. MRI was performed in four groups of 22 subjects each: healthy subjects (I), controls (II) (thalassemia intermedia patients without iron overload), thala…

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…