Search results for "imulation"
showing 10 items of 7271 documents
Controlled Ovarian Stimulation Induces a Functional Genomic Delay of the Endometrium with Potential Clinical Implications
2008
Context: Controlled ovarian stimulation induces morphological, biochemical, and functional genomic modifications of the human endometrium during the window of implantation. Objective: Our objective was to compare the gene expression profile of the human endometrium in natural vs. controlled ovarian stimulation cycles throughout the early-mid secretory transition using microarray technology. Method: Microarray data from 49 endometrial biopsies obtained from LH+1 to LH+9 (n = 25) in natural cycles and from human chorionic gonadotropin (hCG) +1 to hCG+9 in controlled ovarian stimulation cycles (n = 24) were analyzed using different methods, such as clustering, profiling of biological processes…
Neuroplasticity in the Adjustment to Blindness
1999
Loss of vision due to injury to the eyes results in deafferentation of very large areas of the human cortex and poses striking demands on other sensory systems to adjust to blindness in a society that heavily relies on vision. Blind subjects need to extract crucial spatial information from touch and hearing. To accomplish this, plastic trans-modal changes appear to take place by which a larger area of the sensorimotor cortex is devoted to the representation of the reading finger in Braille readers, and parts of the former visual cortex are recruited for the processing of tactile and auditory information.
Endoscopic training during fellowship: A nationwide French study
2022
ABSTRACT Background In France, it is mandatory that gastroenterology fellows have mastered the basic level of endoscopy by the end of training. The aim of this study was to assess improvement in the quality of fellows’ endoscopy training in France during the last four years. Methods All fellows in France in training were eligible for participation. A 21-item questionnaire was sent out. The primary outcome was the completion by fourth year fellows of all the number of procedures recommended. Results were compared with those of a 2016 survey. Results Two-hundred-and-sixty-five fellows responded to the survey. The participation rate was 47.0%. The mean age was 27.3 ± 1.0 years and 56.4% were f…
Electronystagmography in the diagnosis of central vertigo.
2011
Objective: Determine the efficacy and applicability of electronystagmography (ENG) testing in the differential diagnosis between peripheral and central vertigo, through the visual-vestibular interaction test, in patients with vertigo.Method: Patients were submitted to ENG recording. Patients sat on a rotatory chair, which was placed in the middle of a rotary rotatory cylindrical chamber. The rotatory chamber was driven by a direct current engine, which turned it clockwise and counterclockwise, and its internal area was covered with 32 black vertical contrast.Results: All patients underwent rotatory vestibular stimulation by Stop test (VOR), optokinetic stimulation (OKN), and contemporary ro…
The pupillary response to mental overload
1977
The hypothesis that the pupil constricts below base level in situations of mental overload was tested. Subjects had to perform in a four-alternative forced-choice task at 75%, 100%, and 125% the speed of their maximum processing capacity. No indication of a pupillary constriction in the overload situation was found. The pupil dilated under all three conditions. The pupil diameter of male subjects significantly decreased after the sharp increase at the beginning of the experimental phases, while the female subjects’ pupil diameter remained at the same level after the initial increase. The amount of dilation depended on information load for male subjects only. Results were taken as further in…
The Effects of Stochastic Galvanic Vestibular Stimulation on Body Sway and Muscle Activity
2020
Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise (nGVS) modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam.Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions (eyes open/closed with/without rubber-foam) performed without nGVS (intensity: 1 mA, duration: 40 s), the stimulation…
Early cortical processing of vection-inducing visual stimulation as measured by event-related brain potentials (ERP)
2019
Abstract Visual motion stimuli can induce the perception of self-motion in stationary observers (known as vection). In the present study, we investigated the sensory processing underlying vection by measuring the human event-related brain potentials (ERPs) elicited by the movement onset of a visual stimulus. We presented participants a visual stimulus consisting of alternating black-and-white vertical bars that moved in horizontal direction, creating the sensation of vection. The stimulus was presented on a screen that was divided into a central and a surrounding peripheral visual area. Both areas moved independently from each other, resulting in four different movement patterns: the periph…
Illusory contours and specific regions of human extrastriate cortex: evidence from rTMS
2003
Functional magnetic resonance imaging studies showed that perception of illusory contours is associated with extrastriate cortex activation prevailing on the right side. 1 Hz repetitive transcranial magnetic stimulation (rTMS) is able to induce lasting inhibition of cortical activity. The objective of the study was to investigate the role of extrastriate cortex in illusory contour perception inducing 1 Hz rTMS interference in healthy subjects. Eight healthy subjects underwent 1 Hz rTMS (600 pulses) through a figure-of-eight coil over right and left occipital cortex (O1 and O2 of 10/20 EEG system); sham magnetic stimulation on the same sites and right motor cortex rTMS (in three subjects) we…
Mapping of the human visual cortex using image-guided transcranial magnetic stimulation
2002
We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…
Transcranial Direct Current Stimulation over the Right Inferior Parietal Cortex Reduces Transposition Errors in a Syllabic Reordering Task
2021
Evidence derived from functional imaging and brain-lesion studies has shown a strong left lateralization for language, and a complementary right hemisphere dominance for visuospatial abilities. Nevertheless, the symmetrical functional division of the two hemispheres gives no reason for the complexity of the cognitive operations involved in carrying out a linguistic task. In fact, a growing number of neuroimaging and neurostimulation studies suggest a possible right hemisphere involvement in language processing. The objective of this work was to verify the contribution of the left and right parietal areas in a phonological task. We applied anodal transcranial direct current stimulation (tDCS…