Search results for "Sensory Systems"
showing 10 items of 793 documents
The preview benefit for familiar and unfamiliar faces
2013
Abstract Previewing distracters improves visual search – the preview benefit ( Watson & Humphreys, 1997 ). Recent fMRI evidence suggests that the preview benefit rests on active inhibition in brain regions concerned with spatial memory, as well as in content selective areas ( Allen, Humphreys, & Matthews, 2008 ). Using familiar and unfamiliar faces in a preview search task we show that search performance is much better with familiar than with unfamiliar faces. With both types of stimuli we obtained preview benefits of at least 10%, measured in terms of the advantage in reaction time relative to the no preview condition. The preview benefit increased up to 30% when distracter faces and their…
Methodological Aspects of the Application of the Naka-Rushton Equation to Clinical Electroretinogram
1993
The nonlinear relation between stimulus intensity and response amplitude of the electroretinogram (ERG) scotopic b wave can be described by a curve based on the Naka-Rushton (NR) equation. Up to now, the NR equation has been used to assess the features of the normal and pathological ERG, but the best approach for a correct evaluation of the parameters is still debatable. The parameters are thought to be related to the different conditions of retinal activities. The method is well known in experimental laboratories but is quite unusual at the clinical level. In the present paper the derivative analysis of the NR function is proposed as an easier approach to understand the variations of the N…
Human eyes do not need monochromatic aberrations for dynamic accommodation
2017
Purpose To determine if human accommodation uses the eye's own monochromatic aberrations to track dynamic accommodative stimuli. Methods Wavefront aberrations were measured while subjects monocularly viewed a monochromatic Maltese cross moving sinusoidally around 2D of accommodative demand with 1D amplitude at 0.2 Hz. The amplitude and phase (delay) of the accommodation response were compared to the actual vergence of the stimulus to obtain gain and temporal phase, calculated from wavefront aberrations recorded over time during experimental trials. The tested conditions were as follows: Correction of all the subject's aberrations except defocus (C); Correction of all the subject's aberratio…
Effects of a three-month active rehabilitation program on psychomotor performance of lower limbs in subjects with low back pain: a controlled study w…
1998
Proper psychomotor performance is needed in work and in activities of daily living, but among subjects with low back pain this area has been studied Little. The present purpose was to evaluate the effect and permanence of a 3-mo. physical exercise program on the psychomotor performance of lower limbs in subjects with low back pain. The associations between psychomotor performance and intensity of low back pain and subjective disability were also evaluated. 90 subjects with nonspecific, subacute low back pain were assigned to one of the three groups: one given three months intensive training, one home exercise, or the control group. Four measurement sessions were made during the 1-yr. study…
Incidence of savant syndrome in Finland
2000
The general incidence of Savant Syndrome was assessed in Finland. First, a survey was made of all 583 facilities which served people with mental retardation. Second, letters asking for information regarding people with Savant Syndrome were published in two key Finnish journals of the field. We received reports of 45 cases of Savant Syndrome. This makes an incidence rate of 1.4 per 1,000 people with mental retardation. The most common form of exceptional skills was calendar calculation, followed by feats of memory.
Combined EEG and MEG analysis of early somatosensory evoked activity in children and adolescents with focal epilepsies
2006
Abstract Objective The study aimed to evaluate differences between EEG and MEG analysis of early somatosensory evoked activity in patients with focal epilepsies in localizing eloquent areas of the somatosensory cortex. Methods Twenty-five patients (12 male, 13 female; age 4–25 years, mean 11.7 years) were included. Syndromes were classified as symptomatic in 17, idiopathic in 2 and cryptogenic in 6 cases. 10 patients presented with malformations of cortical development (MCD). 122 channel MEG and simultaneous 33-channel EEG were recorded during tactile stimulation of the thumb (sampling rate 769 Hz, band-pass 0.3–260 Hz). Forty-four hemispheres were analyzed. Hemispheres were classified as t…
Management of chronic otitis by middle ear obliteration with blind sac closure of the external auditory canal.
2008
Objective: Description of a technique of middle ear obliteration (MEO) with blind sac closure of the external auditory canal with discussion of the indications for its use in cases of recalcitrant chronic otitis and in far advanced disease. Patients: All patients underwent otologic examination and audiologic and radiologic assessments in a quaternary center. Results: Fifty-three cases of MEO were analyzed. For 9 patients, primary surgery was performed. One case of residual disease was identified. The minimum follow-up was 2 years. Conclusion: The decision to perform a MEO is one that is made only rarely. However, this is a technique that should be part of every otologist`s armamentarium. Wh…
Effect of Corticosteroids on Facial Function after Cerebellopontine Angle Tumor Removal: A Double-Blind Study versus Placebo
2015
The aim of this study was to assess the effect of corticosteroids administered intra- and postoperatively on the occurrence of facial palsy after a cerebellopontine angle (CPA) tumor resection, and to investigate pre- and intraoperative prognostic factors. A multicenter, prospective, randomized, double-blind and versus-placebo study was conducted between 2006 and 2010. Three hundred and ten patients operated on for a CPA tumor (96% vestibular schwannomas, 4% miscellaneous) were included by five participating centers. The population was stratified into patients with small (≤15 mm CPA on axial MRI views) and large tumors. In each group, patients were randomized to receive corticosteroid (1 mg…
Postural Control Mechanisms in Healthy Adults in Sitting and Standing Positions
2015
This study explored differences in the center of pressure in healthy people in a sitting and standing position and with eyes open and closed. With this purpose, 32 healthy participants (16 men, 16 women; M age = 25.2 yr., SD = 10.0, range = 18–55) were measured with an extensiometric force plate. Using a two–way repeated-measures multivariate analysis of variance (MANOVA), the root mean square, velocity, range, and sway, in both visual conditions, had higher values in the standing task than in the sitting task. In the frequency domain, the low-frequency band had higher values during the standing task. For control mechanism variables, mean distance and time were greater when standing while …
Dynamic posturography findings predict balance status in vestibular schwannoma patients.
2007
OBJECTIVE To test whether condition 5 score (C5S) and condition 6 score (C6S) of the sensory organization test of computerized dynamic platform posturography (CDPP) differ between vestibular schwannoma (VS) patients with and without vestibular symptoms. STUDY DESIGN Retrospective review of prospectively collected data. SETTING Tertiary academic referral center. PATIENTS Two hundred and sixteen consecutive patients with a histological diagnosis of a VS (103 women; 113 men; age range, 18-78 years; median, 54 years) who had been preoperatively evaluated by CDPP. A hundred and twelve patients had a history of vertigo, dizziness, and/or imbalance, and 104 patients had neither present nor past ve…