Search results for "auditor."
showing 10 items of 737 documents
Auditory evoked potentials to changes in speech sound duration in anesthetized mice
2018
AbstractElectrophysiological response termed mismatch negativity (MMN) indexes auditory change detection in humans. An analogous response, called the mismatch response (MMR), is also elicited in animals. Mismatch response has been widely utilized in investigations of change detection in human speech sounds in rats and guinea pigs, but not in mice. Since e.g. transgenic mouse models provide important advantages for further studies, we studied processing of speech sounds in anesthetized mice. Auditory evoked potentials were recorded from the dura above the auditory cortex to changes in duration of a human speech sound /a/. In oddball stimulus condition, the MMR was elicited at 53-259 ms laten…
Mismatch negativity (MMN) elicited by changes in phoneme length: A cross-linguistic study
2006
Speech sounds representing different phonetic categories are typically easier to discriminate than sounds belonging to the same category. This phenomenon is referred to as the phoneme boundary effect. We aimed to determine whether, at neural level, this effect is indeed due to crossing the phoneme boundary. The mismatch negativity (MMN) brain response was measured for across- and within-category changes in Finnish phoneme length in native speakers and second-language users of Finnish as well as non-Finnish-speaking subjects. The results showed that the MMN amplitude was enhanced in the native speakers in comparison with the two non-native groups which, in turn, did not differ from each othe…
Auditory cortical and hippocampal local-field potentials to frequency deviant tones in urethane-anesthetized rats: An unexpected role of the sound fr…
2015
Abstract The human brain can automatically detect auditory changes, as indexed by the mismatch negativity of event-related potentials. The mechanisms that underlie this response are poorly understood. We recorded primary auditory cortical and hippocampal (dentate gyrus, CA1) local-field potentials to serial tones in urethane-anesthetized rats. In an oddball condition, a rare (deviant) tone ( p = 0.11) randomly replaced a repeated (standard) tone. The deviant tone was either lower (2200, 2700, 3200, 3700 Hz) or higher (4300, 4800, 5300, 5800 Hz) in frequency than the standard tone (4000 Hz). In an equiprobability control condition, all nine tones were presented at random ( p = 0.11). Diffe…
Beidseitige progrediente Hörminderung als Erstmanifestation eines metastasierenden Pankreaskopfkarzinoms - Kasuistik -
2001
We report the history of a patient who presented first with a progressive unilateral hearing loss and later with a bilateral deafness and an unilateral facial nerve palsy as first and only symptoms of a pancreatic adenocarcinoma. By means of magnetic resonance tomography tumor-suspect lesions in both internal auditory canals were detected. Referring to the results of further examinations these intracanalicular lesions are most probably due to rarely seen bilateral metastasis of a pancreatic adenocarcinoma in the temporal bone. In addition to this rarely diagnosed localisation of metastasis it is rather uncommon that this kind of primary malignoma had not been detected because of gastrointes…
Lateralization Effects on Cerebral Blood Flow in Patients With Unilateral Pulsatile Tinnitus Measured With Arterial Spin Labeling
2020
Purpose: To investigate cerebral blood flow (CBF) differences in patients with left- and right-sided pulsatile tinnitus (LPT and RPT) and healthy controls (HCs) to further explore the lateralization effects of PT using arterial spin labeling (ASL). Methods: ASL data from 21 RPT patients, 17 LPT patients and 21 HCs were reviewed. Voxel-wise analysis and region of interest analysis were performed to explore differences in CBF among the three groups. Tinnitus Handicap Inventory (THI) score and tinnitus duration were obtained from each patient. Results: Voxel-wise analysis showed that the CBF of the left inferior parietal gyrus was increased in both RPT and LPT patients compared with HCs (P < 0…
Brainstem Auditory Evoked Potentials and Visual Potentials in Kawasaki Disease: An Observational Monocentric Study
2020
Background: Kawasaki Disease is a systemic vasculitis, particularly involving coronary arteries. Rare involvement of other vascular districts is described, as central nervous system arteries, leading to a vasculitic neuropathy. Sensorineural hearing loss and alterations of evoked potentials are uncommonly reported complications.Methods: In an observational monocentric study, 59 children (37 males; 22 females; mean age: 2.7 ± 2.2 years) with documented Kawasaki Disease were enrolled. No risk factors for hearing loss and/or neurological impairment were identified in the cohort. Brainstem auditory evoked potentials and visual evoked potentials were correlated with clinical, hamatological and r…
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…
Importance of the left auditory areas in chord discrimination in music experts as demonstrated by MEG
2011
The brain basis behind musical competence in its various forms is not yet known. To determine the pattern of hemispheric lateralization during sound-change discrimination, we recorded the magnetic counterpart of the electrical mismatch negativity (MMNm) responses in professional musicians, musical participants (with high scores in the musicality tests but without professional training in music) and non-musicians. While watching a silenced video, they were presented with short sounds with frequency and duration deviants and C major chords with C minor chords as deviants. MMNm to chord deviants was stronger in both musicians and musical participants than in non-musicians, particularly in thei…
Cis-diaminedichloro platinum ototoxicity. An experimental study.
1985
Four groups of guinea pigs received different doses of cis-platinum. SEM and TEM showed a direct relation between the dose and the damage. The first row of OHC is the first one to be damaged. The IHC are more resistant than the OHC. The pattern of destruction is similar to the one produced by the aminoglucoside antibiotics.
Steroid and vasoactive treatment for acute deafness after attempted hearing preservation acoustic neuroma surgery.
2004
<i>Objective:</i> To investigate whether intravenous steroid and vasoactive therapy in the acute postoperative period improves hearing outcome in patients who develop acute deafness after attempted hearing preservation surgery for acoustic neuroma (AN) through a retrosigmoid or a middle cranial fossa approach. <i>Study Design and Setting:</i> Retrospective controlled study in a tertiary care center. Thirty-six patients who had developed acute deafness after hearing preservation surgery for treatment of an AN were reviewed. Preoperative AAOHNS hearing class was A in 2, B in 2 and D in 32 patients. Twenty-seven patients were treated with prednisolone, hydroxyethyl star…