Search results for "Potentials"
showing 10 items of 1072 documents
Brain slow waves preceding time-locked visuo-motor performance.
1993
According to previous findings (Konttinen and Lyytinen, 1992), the slow brain negativity preceding the trigger pull in rifle‐shooting tends to be decreased in successful shots among experienced marksmen, whereas no such pattern is found among inexperienced subjects. This effect was interpreted as resulting mainly from optimal arousal. However, another explanation is examined here. The aim of the experiment was to investigate slow electrocortical changes associated with motor regulation and visual aiming related to shooting performance. Four variations on a shooting task were used, in which the visual and motor components were contrasted. Motor activity related to gun stabilization was found…
Evoked otoacoustic emissions and pure tone threshold audiometry in patients receiving cisplatinum therapy.
1993
Eight children and young adults with cancer were evaluated serially using pure tone audiometry as well as registration of click-evoked otoacoustic emissions (EOAE) 1 day prior to therapy as well as after various numbers of doses of cisplatinum. A reduction of EOAE-amplitudes following cisplatinum therapy was observed in all patients. This reduction tended to recover after the end of cisplatinum administration. Since EOAE are believed to result from cochlear bio-mechanical processes, the reduced emissions are interpreted as signs of cochlear dysfunction. We conclude, that EOAE testing may be a simple, non-invasive method that may detect early, transient functional impairment of hearing due t…
Assessing audiological, pathophysiological and psychological variables in tinnitus patients with or without hearing loss
2010
The aim of this work is to study the characteristics of tinnitus both in normal hearing subjects and in patients with hearing loss. The study considered tinnitus sufferers, ranging from 21 to 83 years of age, who were referred to the Audiology Section of Palermo University in the years 2006–2008. The following parameters were considered: age, sex, hearing threshold, tinnitus laterality, tinnitus duration, tinnitus measurements and subjective disturbance caused by tinnitus. The sample was divided into Group1 (G1), 115 subjects with normal hearing, and Group2 (G2), 197 subjects with hearing loss. Especially for G2, there was a predominance of males compared to females (P = 0.011); the highest…
Brain Slow Potentials Reflecting Successful Shooting Performance
1995
Preparatory brain activity from frontal, centro-lateral, and occipital areas were recorded from top-level rifle shooters during shooting performance. The aim of the study was to examine the relation of brain slow potentials to qualitative (rifle holding) and quantitative (hit) aspects of superior shooting performance. For this purpose, a typology of slow potentials (SPs) was developed. The resulting SP types were used for unraveling the associations between the electrocortical activity and behavioral output. The main finding was that frontal positivity was associated with successful performance, but only if the central-right SP was more negative than the central-left one. This finding was e…
Distraction of task-relevant information processing by irrelevant changes in auditory, visual, and bimodal stimulus features: A behavioral and event-…
2009
Distractibility with auditory, visual, and bimodal stimulus changes was investigated using an audio-visual distraction paradigm. Participants were asked to discriminate between equiprobable short and long audio-visual stimuli. Infrequently, the auditory, the visual, or both parts of the stimuli changed. These rare deviations (deviants) were irrelevant for the actual task. The influence of the three types of deviant stimuli on the processing of task-relevant information was assessed with behavioral and event-related potential (ERP) measures assuming that bimodal deviants would lead to an increase in distraction. Behavioral and ERP results did not support this assumption, as reaction time (RT…
Differential effects on the laser evoked potential of selectively attending to pain localisation versus pain unpleasantness
2004
Abstract Objective : To determine the effects on the laser evoked potential (LEP) of selectively attending to affective (unpleasantness) versus sensory-discriminative (localisation) components of pain. Methods : LEPs, elicited by painful CO 2 laser stimulation of two areas of the right forearm, were recorded from 62 electrodes in 21 healthy volunteers, during three tasks that were matched for generalised attention: Localisation (report stimulus location), Unpleasantness (report stimulus unpleasantness), Control (report pain detection). LEP components are named by polarity, latency, and electrode. Results : N300-T7 peak amplitude was significantly greater during Localisation than Unpleasantn…
Perinatal cerebral insults alter auditory event-related potentials.
2011
Background: Auditory event-related potentials (AERPs) can be used as indices of neural information processing. Altered AERPs have been reported in children and young adults with frontal lobe infarction. Aim: To test the hypothesis that perinatal brain injury affects cortical auditory processing. Methods: We assessed AERPs at term. 6 and 12 months of age in preterm infants [n = 9. median gestational age (GA) 27.9, range 23.9-30.0 wk], term infants with perinatal intracerebral hemorrhage (ICH) [n = 5, GA 40.3, range 37.4-42.3 wk], and term infants with perinatal asphyxia In [n = 4. GA 39.4. range 37.9-40.3 wk]. Healthy preterm (n = 16) and term infants (n = 22) served as controls. A harmonic …
Laterality effects in motor learning by mental practice in right-handers.
2014
Converging evidences suggest that mental movement simulation and actual movement production share similar neurocognitive and learning processes. Although a large body of data is available in the literature regarding mental states involving the dominant arm, examinations for the nondominant arm are sparse. Does mental training, through motor-imagery practice, with the dominant arm or the nondominant arm is equally efficient for motor learning? In the current study, we investigated laterality effects in motor learning by motor-imagery practice. Four groups of right-hander adults mentally and physically performed as fast and accurately as possible (speed/accuracy trade-off paradigm) successive…
Vestibular evoked myogenic potential findings in multiple sclerosis.
2013
Abstract Introduction Multiple sclerosis is an inflammatory disease involving the occurrence of demyelinating, chronic neurodegenerative lesions in the central nervous system. We studied vestibular evoked myogenic potentials (VEMPs) in this pathology, to allow us to evaluate the saccule, inferior vestibular nerve and vestibular-spinal pathway non-invasively. Methods There were 23 patients diagnosed with multiple sclerosis who underwent VEMP recordings, comparing our results with a control group consisting of 35 healthy subjects. We registered p13 and n23 wave latencies, interaural amplitude difference and asymmetry ratio between both ears. Subjects also underwent an otoscopy and audiometric…
EDSS correlated analysis of median nerve somatosensory evoked potentials in multiple sclerosis
2001
Median nerve somatosensory evoked potentials (SEP) were recorded in 30 patients with multiple sclerosis. The examined patients had an expanded disability status scale (EDSS) between 0 and 6. The primary cortical potential N20, the subcortical potentials P14, N13b, N13a and the peripheral potential P9 were recorded simultaneously. In 5 patients normal SEP were observed (group 1), and in 6 patients there were consecutive disturbances of the somatosensory pathway (group 3). In 19 patients subcortical potentials were abnormal or absent while the following potentials were normal or identified which pattern corresponds to amplification within CNS structures (group 2). The EDSS of groups 1 and 2 w…