Search results for "senso"

Maintenance of anticoagulant and antiplatelet agents for patients undergoing vitreoretinal surgery

2010

International audience; Purpose: To establish the prevalence of anticoagulant, aspirin, and clopidogrel use in patients undergoing vitreoretinal surgery, and to compare the outcome of peribulbar anesthesia between users and non‐users. Methods: We conducted a retrospective case series in one academic center between January and June 2009. We analyzed the chart of 239 eyes who underwent posterior segment surgery with peribulbar anesthesia. No changes in the anticoagulant regimen were made prior to surgery. We divided patients into 7 groups: group 1: patients with no anticoagulants and 6 groups defined according to the type of anticoagulant or antiplatelet medication. Results: 239 eyes (206 pat…

Role of the tear film in the optical quality of the human eye.

2007

This paper reviews recent studies of the role of the tear film in the optical quality of the eye. Recent investigations focus on the dynamics of the tear film after a blink and its important role in the optical quality of the eye. The results in this review were used in an attempt to understand the optical and visual impact of tear-film breakup in normal eyes and dry eyes. It was noted that patients with dry-eye syndrome have large optical aberrations compared with those in normal eyes, which may be the cause of blurry vision associated with the syndrome. In addition, instillation of artificial tears reduces optical aberrations and thus improves the optical quality of vision in these patien…

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…

Binocular Vision in Patients with Multiple Sclerosis.

2021

Amparo Gil-Casas,1,2 David P Piñero-Llorens,2 Ainhoa Molina-Martin2 1Clínica Optométrica, Fundació Lluís Alcanyís, University of Valencia, Valencia, Spain; 2Optics and Visual Perception Group (GOPV), Department of Optics, Pharmacology, and Anatomy, University of Alicante, Alicante, SpainCorrespondence: Ainhoa Molina-MartinDepartment of Optics, Pharmacology, and Anatomy, University of Alicante, Carretera San Vicente del Raspeig, San Vicente del Raspeig, 03690, Alicante, SpainTel +34 965 903-400Email ainhoa.molina@ua.esPurpose: Oculomotor disorders have been reported in multiple sclerosis (MS) in up to 80% of cases. There have …

Quantifying Intermodal Distraction by Emotion During Math Performance: An Electrophysiological Approach

2019

Emotionally engaging stimuli are powerful competitors for limited attention capacity. In the cognitive neuroscience laboratory, the presence of task-irrelevant emotionally arousing visual distractors prompts decreased performance and attenuated brain responses measured in concurrent visual tasks. The extent to which distraction effects occur across different sensory modalities is not yet established, however. Here, we examined the extent and time course of competition between a naturalistic distractor sound and a visual task stimulus, using dense-array electroencephalography (EEG) recordings from 20 college students. Steady-state visual evoked potentials (ssVEPs) were quantified from EEG, e…

Patients with Minimal Hepatic Encephalopathy Show Altered Thermal Sensitivity and Autonomic Function

2021

Cirrhotic patients may experience alterations in the peripheral nervous system and in somatosensory perception. Impairment of the somatosensory system could contribute to cognitive and motor alterations characteristic of minimal hepatic encephalopathy (MHE), which affects up to 40% of cirrhotic patients. We assessed the relationship between MHE and alterations in thermal, vibration, and/or heat pain sensitivity in 58 cirrhotic patients (38 without and 20 with MHE according to Psychometric Hepatic Encephalopathy Score) and 39 controls. All participants underwent attention and coordination tests, a nerve conduction study, autonomic function testing, and evaluation of sensory thresholds (vibra…

2017

The mere presence of a depiction of eyes can elicit a sense of being watched in the perceiver. To this date, the factors affecting the intensity of this sense of being watched, however, have not been investigated. In the present experiment, we tested the impact of two potentially relevant variables: arousal (manipulated using specific musical pieces) and duration of the perceptual episode (manipulated using presentation times of 200 ms and 10 s, respectively). We asked participants to report how intensely they felt being watched while we exposed them to various observation cues ranging from human eyes to surveillance cameras. We found that, on average, reported intensities were higher if pa…

Somatosensory Illusions Elicited by Sham Electromagnetic Field Exposure: Experimental Evidence for a Predictive Processing Account of Somatic Symptom…

2020

OBJECTIVE According to the predictive processing theory of somatic symptom generation, body sensations are determined by somatosensory input and central nervous predictions about this input. We examined how expectations shape predictions and consequently bodily perceptions in a task eliciting illusory sensations as laboratory analogue of medically unexplained symptoms. METHODS Using the framework of signal detection theory, the influence of sham Wi-Fi on response bias (c) and somatosensory sensitivity (d') for tactile stimuli was examined using the somatic signal detection task (SSDT). A healthy student sample (n = 83) completed the SSDT twice (sham Wi-Fi on/off) in a randomized order after…

Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF).

2020

The exact causes of Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF, i.e., experience of somatic symptoms attributed to low-level electromagnetic fields) are still unknown. Psychological causation such as nocebo effects seem plausible. This study aimed to experimentally induce a nocebo effect for somatic symptom perception and examined whether it was reproducible after one week. We also examined whether these effects were associated with increased sympathetic activity and whether interoceptive accuracy (IAcc) moderated these relationships. Participants were recruited from the general population and instructed that electromagnetic exposure can enhance somat…

Effect of Different Display Types on Vection and Its Interaction With Motion Direction and Field Dependence

2017

Illusory self-motion (vection) can be generated by visual stimulation. The purpose of the present study was to compare behavioral vection measures including intensity ratings, duration, and onset time across different visual display types. Participants were exposed to a pattern of alternating black-and-white horizontal or vertical bars that moved either in vertical or horizontal direction, respectively. Stimuli were presented on four types of displays in randomized order: (a) large field of view dome projection, (b) combination of three computer screens, (c) single computer screen, (d) large field of view flat projection screen. A Computer Rod and Frame Test was used to measure field depen…