Sample records for audiometry evoked response

  1. Brain stem evoked response audiometry A Review


    Balasubramanian Thiagarajan


    Brain stem evoked response audiometry (BERA) is a useful objective assessement of hearing. Major advantage of this procedure is its ability to test even infants in whom conventional audiometry may not be useful. This investigation can be used as a screening test for deafness in high risk infants. Early diagnosis and rehabilitation will reduce disability in these children. This article attempts to review the published literature on this subject. Methadology: Internet search using goog...

  2. Evoked response audiometry used in testing auditory organs of miners

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    Malinowski, T.; Klepacki, J.; Wagstyl, R.


    The evoked response audiometry method of testing hearing loss is presented and the results of comparative studies using subjective tonal audiometry and evoked response audiometry in tests of 56 healthy men with good hearing are discussed. The men were divided into three groups according to age and place of work: work place without increased noise; work place with noise and vibrations (at drilling machines); work place with noise and shocks (work at excavators in surface coal mines). The ERA-MKII audiometer produced by the Medelec-Amplaid firm was used. Audiometric threshhold curves for the three groups of tested men are given. At frequencies of 500, 1000 and 4000 Hz mean objective auditory threshhold was shifted by 4-9.5 dB in comparison to the subjective auditory threshold. (21 refs.) (In Polish)


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    Full Text Available INTRODUCTION: The subjective assessment of hearing is primarily done by pure tone audiometry. It is commonly undertaken test which can tell us the hearing acuity of a person when carried under ideal conditions. However, not infrequently the otologists encounter a difficulty to do subjective audiometry or in those circumstances where the test results are not correlating with the disease in question. Hence they have to depend upon the objective tests to get a workable knowledge about the patients hearing threshold. Of the various objective tests available the most popular are Brain stem evoked response audiometry –non-invasive and more standardized parameter, Electro-cochleography, auditory steady state response. Otoacoustic Emission test (OAE Otoacoustic emission doesn’t measure the hearing acuity, it gives us an idea whether there is any deafness or not. But BERA is useful in detecting and quantification of deafness in the difficult-to-test patients like infants, mentally retarded people, malingers, deeply sedated and anaesthetized patients. It determines objectively the nature of deafness (i.e., whether sensory or neural in difficult-to-test patients. It helps to locate the site of lesion in retro-cochlear pathologies (in an area from spiral ganglion of the cochlear nerve to midbrain (inferior colliculus. Study of central auditory disorders is possible. Study of maturity of central nervous system in newborns, objective identification of brain death, assessing prognosis in comatose patients are other uses. Before starting a BERA lab in a hospital it is mandatory to standardize the normal values in a randomly selected group of persons with certain criteria like; normal ears with intact T.M and without any complaints of loss of hearing. Persons aged between 05 to 60 years are taken for this study. The study group included both males and females. The aim of this study is to assess the hearing pathway in normal hearing individuals and compare


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    Praveen S


    Full Text Available BACKGROUND AND OBJECTIVE Type-2 Diabetes Mellitus (T2DM causes pathophysiological changes in multiple organ system. The peripheral, autonomic and central neuropathy is known to occur in T2DM, which can be studied electrophysiologically. AIM Present study is aimed to evaluate functional integrity of auditory pathway in T2DM by Brainstem Evoked Response Audiometry (BERA. MATERIAL AND METHOD In the present case control study, BERA was recorded from the scalp of 20 T2DM patients aged 30-65 years and were compared with age matched 20 healthy controls. The BERA was performed using EMG Octopus, Clarity Medical Pvt. Ltd. The latencies of wave I, III, V and Wave I-III, I-V and III-V interpeak latencies of both right and left ear were recorded at 70dBHL. STATISTICAL RESULT AND USE Mean±SD of latencies of wave I, III, V and interpeak latency of I-III, I-V and III-V were estimated of T2DM and healthy controls. The significant differences between the two groups were assessed using unpaired student ‘t’ test for T2DM and control groups using GraphPad QuickCalcs calculator. P value <0.05 was considered to be significant. RESULT In T2DM BERA study revealed statistically significant (p<0.05 prolonged latencies of wave I, III and V in both right (1.81±0.33ms, 3.96±0.32ms, 5.60±0.25ms and left (1.96±0.24ms, 3.79±0.22ms, 5.67±0.25ms ear as compared to controls at 70dB. Wave III-V interpeak latency of left ear (1.87±0.31, 1.85±0.41ms and wave I-III (2.51±0.42ms, 1.96±0.48ms and III-V (2.01±0.43ms, 1.76±0.45ms of right ear was prolonged in diabetic patient as compared to controls, although no significant difference was obtained (p<0.05. INTERPRETATION AND CONCLUSION Increase in absolute latencies and interpeak latencies inT2DM patients suggest involvement of central neuronal axis at the level of brain stem and midbrain.

  5. Age-related hearing loss in dogs : Diagnosis with Brainstem-Evoked Response Audiometry and Treatment with Vibrant Soundbridge Middle Ear Implant.


    ter Haar, G.


    Age-related hearing loss (ARHL) is the most common cause of acquired hearing impairment in dogs. Diagnosis requires objective electrophysiological tests (brainstem evoked response audiometry [BERA]) evaluating the entire audible frequency range in dogs. In our laboratory a method was developed to deliver tone bursts ranging in frequency from 1 - 32 kHz for frequency-specific assessment of the cochlea in dogs. Brainstem auditory evoked responses to a click (CS) and to 1, 2, 4, 8, 12, 16, 24, a...

  6. Age-related hearing loss in dogs : Diagnosis with Brainstem-Evoked Response Audiometry and Treatment with Vibrant Soundbridge Middle Ear Implant.

    NARCIS (Netherlands)

    ter Haar, G.


    Age-related hearing loss (ARHL) is the most common cause of acquired hearing impairment in dogs. Diagnosis requires objective electrophysiological tests (brainstem evoked response audiometry [BERA]) evaluating the entire audible frequency range in dogs. In our laboratory a method was developed to de

  7. Auditory evaluation of the microcephalic children with brain stem evoked response audiometry (BERA). (United States)

    Das, Piyali; Bandyopadhyay, Manimay; Ghugare, Balaji W; Ghate, Jayshree; Singh, Ramji


    Microcephaly implies a reduced occipito-frontal circumference (Audiometry (BERA) to locate the exact site of lesion resulting in the auditory impairment, so that appropriate early rehabilitative measures can be taken. The study revealed that absolute peak latency of wave V, inter peak latencies of III-V and I-V were significantly higher (P- value < 0.05 in each case) in microcephalics than the normal children. Auditory impairment in microcephaly is a common neurodeficit that can be authentically assessed by BERA. The hearing impairment in microcephalics is mostly due to insufficiency of central components of auditory pathway at the level of brainstem, function of peripheral structures being almost within normal limit.

  8. A study of brainstem evoked response audiometry in high-risk infants and children under 10 years of age

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    Ramanathan Thirunavukarasu


    Full Text Available Aims: To evaluate the hearing threshold and find the incidence of hearing loss in infants and children belonging to high-risk category and analyze the common risk factors. Subjects and Methods: Totally, 125 infants and children belonging to high-risk category were subjected to brainstem evoked response audiometry. Clicks were given at the rate of 11.1 clicks/s. Totally, 2000 responses were averaged. The intensity at which wave V just disappears was established as hearing the threshold. Degree of impairment and risk factors were analyzed. Results: Totally, 44 (35.2% were found to have sensorineural hearing loss. Totally, 30 children with hearing loss (68% belonged to age group 1-5 years. Consanguineous marriage was the most commonly associated risk factor. Majority (34 had profound hearing loss. Conclusion: Newborn screening is mandatory to identify hearing loss in the prelinguistic period to reduce the burden of handicap in the community. The need of the hour is health education and genetic counseling to decrease the hereditary hearing loss, as hearing impairment due to perinatal factors has reduced due to recent medical advancements.

  9. Potenciais evocados auditivos de tronco encefálico de ex-usuários de drogas Brain stem evoked response audiometry of former drug users

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    Tainara Milbradt Weich


    Full Text Available As drogas ilícitas são conhecidas pelos seus efeitos deletérios no sistema nervoso central; no entanto, elas também podem atingir o sistema auditivo, provocando alterações. OBJETIVOS: Analisar e comparar os resultados dos potenciais evocados auditivos de tronco encefálico (PEATE de frequentadores de grupos de apoio a ex-usuários de drogas. MÉTODO: Estudo transversal, não experimental, descritivo e quantitativo. A amostra foi composta por 17 indivíduos divididos conforme o tipo de droga mais consumida: 10 indivíduos no grupo maconha (G1 e sete no grupo crack/cocaína (G2. Eles foram subdivididos pelo tempo de uso de drogas: um a cinco anos, seis a 10 anos e mais que 15 anos. A avaliação foi feita por meio de anamnese, audiometria tonal liminar, medidas de imitância acústica e PEATE. RESULTADOS: Ao comparar os resultados de G1 e G2, independente do tempo de uso de drogas, não se observou diferença estatisticamente significante nas latências absolutas e nos intervalos interpicos. No entanto, apenas cinco dos 17 indivíduos tiveram PEATE com resultados adequados para a faixa etária. CONCLUSÃO: Independentemente do tempo de utilização das drogas, o uso de maconha e crack/cocaína pode provocar alterações difusas no tronco encefálico, comprometendo a transmissão do estímulo auditivo.Illicit drugs are known for their deleterious effects upon the central nervous system and more specifically for how they adversely affect hearing. OBJECTIVE: This study aims to analyze and compare the hearing complaints and the results of brainstem evoked response audiometry (BERA of former drug user support group goers. METHODS: This is a cross-sectional non-experimental descriptive quantitative study. The sample consisted of 17 subjects divided by their preferred drug of use. Ten individuals were placed in the marijuana group (G1 and seven in the crack/cocaine group (G2. The subjects were further divided based on how long they had been using

  10. Cortical Response of Retardates for AER Audiometry (United States)

    Hogan, Donald D.


    Averaged auditory evoked responses were obtained from 15 retarded and motor-handicapped subjects and from 15 nonretarded subjects in order to investigate comparative responsiveness and response features. (Author)

  11. Audiometria de resposta evocada de acordo com sexo e idade: achados e aplicabilidade Evoked response audiometry according to gender and age: findings and usefulness

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    Edmir Américo Lourenço


    Full Text Available A audiometria de respostas evocadas (ABR é um registro não-invasivo de potenciais elétricos auditivos nos primeiros 12 milissegundos, da orelha média ao córtex auditivo. ABR é importante na avaliação otoneurológica. OBJETIVO: Esclarecer as utilidades do exame, faixas etárias e sexo com maior incidência e topodiagnóstico segundo as latências absolutas e os intervalos interpicos. CASUÍSTICA E MÉTODO: Neste estudo retrospectivo foram analisados 403 prontuários de ABR realizados em clínica particular na cidade de Jundiaí/SP, Brasil, suspeitos de alteração auditiva e/ou doença do SNC, com os pacientes divididos por sexo e faixa etária. RESULTADOS E CONCLUSÕES: ABR é um importante exame para determinar a integridade da via auditiva, limiares eletrofisiológicos e topodiagnóstico, embora o teste não indique a etiologia das alterações. Foi demonstrado que ocorreu maior incidência de achados retrococleares na faixa etária de 12-20 anos e sexo masculino, contudo crianças menores de um ano com fatores de risco não apresentaram um aumento na incidência de alterações condutivas, cocleares e retrococleares em relação à população geral estudada. As latências absolutas das ondas I, III e V foram maiores no sexo masculino e as alterações dos intervalos interpicos foram similares em ambos os sexos, sendo que o intervalo I-III foi o mais freqüentemente alterado.Auditory evoked brainstem responses (ABR is a non-invasive electrical potential registration which evaluates the auditory tract from the middle ear to the auditory cortex in the first 12 milliseconds (ms. The ABR is an important otoneurological evaluation. AIM: confirm the test's usefulness, major incidence and topography according to are range gender considering the absolute latencies of the waves and interpeak intervals. MATERIALS AND METHOD: we retrospectively analyzed 403 tests from a private clinic in the city of Jundiaí-São Paulo State-Brazil, from

  12. Response and Reinforcement in Operant Audiometry. (United States)

    Primus, Michael A.


    Response and reinforcement features of operant discrimination paradigms used in audiometric assessment were investigated with normal 17-month-old children. Findings indicated more responses prior to onset of habituation when response tasks involved complex central processing skills and a twofold increase in number of subject responses when…

  13. Response Strength of Young Children in Operant Audiometry. (United States)

    Primus, Michael A.; Thompson, Gary


    An operant conditioning discrimination paradigm was evaluated of relationships between response behavior of young children and two stimulus components of the paradigm, the discriminative stimulus and the reinforcing stimulus. Findings revealed the effects of schedules of reinforcement, novel reinforcement, and age. (Author/CL)

  14. Brainstem response audiometry in the determination of hearing loss

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    J.F.C. van der Drift (Frank)


    textabstractThe earlier hearing disorders are diagnosed in infants and children the sooner treatment and revalidation can be organised. Consequently. determining the hearing at the youngest age possible is important to promote the development of language and communication. Brainstern response audiom

  15. Notched-noise embedded frequency specific chirps for objective audiometry using auditory brainstem responses

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    Farah I. Corona-Strauss


    Full Text Available It has been shown recently that chirp-evoked auditory brainstem responses (ABRs show better performance than click stimulations, especially at low intensity levels. In this paper we present the development, test, and evaluation of a series of notched-noise embedded frequency specific chirps. ABRs were collected in healthy young control subjects using the developed stimuli. Results of the analysis of the corresponding ABRs using a time-scale phase synchronization stability (PSS measure are also reported. The resultant wave V amplitude and latency measures showed a similar behavior as for values reported in literature. The PSS of frequency specific chirp-evoked ABRs reflected the presence of the wave V for all stimulation intensities. The scales that resulted in higher PSS are in line with previous findings, where ABRs evoked by broadband chirps were analyzed, and which stated that low frequency channels are better for the recognition and analysis of chirp-evoked ABRs. We conclude that the development and test of the series of notched-noise embedded frequency specific chirps allowed the assessment of frequency specific ABRs, showing an identifiable wave V for different intensity levels. Future work may include the development of a faster automatic recognition scheme for these frequency specific ABRs.

  16. In-air evoked potential audiometry of grey seals (Halichoerus grypus) from the North and Baltic Seas. (United States)

    Ruser, Andreas; Dähne, Michael; Sundermeyer, Janne; Lucke, Klaus; Houser, Dorian S; Finneran, James J; Driver, Jörg; Pawliczka, Iwona; Rosenberger, Tanja; Siebert, Ursula


    In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1-20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4-20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.

  17. Comparison of pure tone audiometry and auditory steady-state responses in subjects with normal hearing and hearing loss. (United States)

    Ozdek, Ali; Karacay, Mahmut; Saylam, Guleser; Tatar, Emel; Aygener, Nurdan; Korkmaz, Mehmet Hakan


    The objective of this study is to compare pure tone audiometry and auditory steady-state response (ASSR) thresholds in normal hearing (NH) subjects and subjects with hearing loss. This study involved 23 NH adults and 38 adults with hearing loss (HI). After detection of behavioral thresholds (BHT) with pure tone audiometry, each subject was tested for ASSR responses in the same day. Only one ear was tested for each subject. The mean pure tone average was 9 ± 4 dB for NH group and 57 ± 14 for HI group. There was a very strong correlation between BHT and ASSR measurements in HI group. However, the correlation was weaker in the NH group. The mean differences of pure tone average of four frequencies (0.5, 1, 2, and 4 kHz) and ASSR threshold average of same frequencies were 13 ± 6 dB in NH group and 7 ± 5 dB in HI group and the difference was significant (P = 0.01). It was found that 86% of threshold difference values were less than 20 dB in NH group and 92% of threshold difference values were less than 20 dB in HI group. In conclusion, ASSR thresholds can be used to predict the configuration of pure tone audiometry. Results are more accurate in HI group than NH group. Although ASSR can be used in cochlear implant decision-making process, findings do not permit the utilization of the test for medico-legal reasons.

  18. Brainstem response audiometry in the determination of low-frequency hearing loss : a study of various methods for frequency-specific ABR-threshold assessment

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    E.A.G.J. Conijn


    textabstractBrainstem Electric Response Audiometry (BERA) is a method to visualize some of the electric activity generated in the auditory nerve and the brainstem during the processing of sound. The amplitude of the Auditory Brainstem Response (ABR) is very small (0.05-0.5 flV). The potentials origi

  19. ABR Audiometry in Cornelia De Lange Syndrome. (United States)

    Brown, Denice P.

    Eight children (ages 13 days to 5 years) with a diagnosis of Cornelia de Lange syndrome received audiologic evaluation consisting of immittance audiometry and auditory brainstem response audiometry to air and bone conducted "click" stimuli, as behavioral testing was unreliable due to patient age and/or developmental delay. Developmental…

  20. Brainstem auditory evoked response: application in neurology

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    Carlos A. M. Guerreiro


    Full Text Available The tecnique that we use for eliciting brainstem auditory evoked responses (BAERs is described. BAERs are a non-invasive and reliable clinical test when carefully performed. This test is indicated in the evaluation of disorders which may potentially involve the brainstem such as coma, multiple sclerosis posterior fossa tumors and others. Unsuspected lesions with normal radiologic studies (including CT-scan can be revealed by the BAER.

  1. Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma - a prospective study

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    Lau, S.K.; Wei, W.I.; Sham, J.S.T.; Choy, D.T.K.; Hui, Y. (Queen Mary Hospital, Hong Kong (Hong Kong))


    A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway. (Author).

  2. Somatosensory evoked response: application in neurology

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    Carlos A. M. Guerreiro


    Full Text Available One technique used for short-latency somatosensory evoked response (SER is described. SER following nerve stimulation is a unique non-invasive, clinical test used to evaluate the somatosensory pathways. It tests the physiological function of the median nerve, the brachial plexus, the C6-7 cervical roots, cervical spinal cord, the cuneate nuclei, the medial lemniscus, the thalamus, and the contralateral sensory cortex. It has been shown to be a reliable and useful clinical test partiicularly in multiple sclerosis and comatose patients. The promising technique of SER following peroneal nerve stimulation is mentioned.

  3. Speech Evoked Auditory Brainstem Response in Stuttering

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    Ali Akbar Tahaei


    Full Text Available Auditory processing deficits have been hypothesized as an underlying mechanism for stuttering. Previous studies have demonstrated abnormal responses in subjects with persistent developmental stuttering (PDS at the higher level of the central auditory system using speech stimuli. Recently, the potential usefulness of speech evoked auditory brainstem responses in central auditory processing disorders has been emphasized. The current study used the speech evoked ABR to investigate the hypothesis that subjects with PDS have specific auditory perceptual dysfunction. Objectives. To determine whether brainstem responses to speech stimuli differ between PDS subjects and normal fluent speakers. Methods. Twenty-five subjects with PDS participated in this study. The speech-ABRs were elicited by the 5-formant synthesized syllable/da/, with duration of 40 ms. Results. There were significant group differences for the onset and offset transient peaks. Subjects with PDS had longer latencies for the onset and offset peaks relative to the control group. Conclusions. Subjects with PDS showed a deficient neural timing in the early stages of the auditory pathway consistent with temporal processing deficits and their abnormal timing may underlie to their disfluency.

  4. Bayesian analysis of MEG visual evoked responses

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    Schmidt, D.M.; George, J.S.; Wood, C.C.


    The authors developed a method for analyzing neural electromagnetic data that allows probabilistic inferences to be drawn about regions of activation. The method involves the generation of a large number of possible solutions which both fir the data and prior expectations about the nature of probable solutions made explicit by a Bayesian formalism. In addition, they have introduced a model for the current distributions that produce MEG and (EEG) data that allows extended regions of activity, and can easily incorporate prior information such as anatomical constraints from MRI. To evaluate the feasibility and utility of the Bayesian approach with actual data, they analyzed MEG data from a visual evoked response experiment. They compared Bayesian analyses of MEG responses to visual stimuli in the left and right visual fields, in order to examine the sensitivity of the method to detect known features of human visual cortex organization. They also examined the changing pattern of cortical activation as a function of time.

  5. 21 CFR 882.1870 - Evoked response electrical stimulator. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring...

  6. Audiometry screening and interpretation. (United States)

    Walker, Jennifer Junnila; Cleveland, Leanne M; Davis, Jenny L; Seales, Jennifer S


    The prevalence of hearing loss varies with age, affecting at least 25 percent of patients older than 50 years and more than 50 percent of those older than 80 years. Adolescents and young adults represent groups in which the prevalence of hearing loss is increasing and may therefore benefit from screening. If offered, screening can be performed periodically by asking the patient or family if there are perceived hearing problems, or by using clinical office tests such as whispered voice, finger rub, or audiometry. Audiometry in the family medicine clinic setting is a relatively simple procedure that can be interpreted by a trained health care professional. Pure-tone testing presents tones across the speech spectrum (500 to 4,000 Hz) to determine if the patient's hearing levels fall within normal limits. A quiet testing environment, calibrated audiometric equipment, and appropriately trained personnel are required for in-office testing. Pure-tone audiometry may help physicians appropriately refer patients to an audiologist or otolaryngologist. Unilateral or asymmetrical hearing loss can be symptomatic of a central nervous system lesion and requires additional evaluation.

  7. A web-based audiometry database system. (United States)

    Yeh, Chung-Hui; Wei, Sung-Tai; Chen, Tsung-Wen; Wang, Ching-Yuang; Tsai, Ming-Hsui; Lin, Chia-Der


    To establish a real-time, web-based, customized audiometry database system, we worked in cooperation with the departments of medical records, information technology, and otorhinolaryngology at our hospital. This system includes an audiometry data entry system, retrieval and display system, patient information incorporation system, audiometry data transmission program, and audiometry data integration. Compared with commercial audiometry systems and traditional hand-drawn audiometry data, this web-based system saves time and money and is convenient for statistics research.

  8. A user-operated audiometry method based on the maximum likelihood principle and the two-alternative forced-choice paradigm

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    Schmidt, Jesper Hvass; Brandt, Christian; Pedersen, Ellen Raben


    response criteria. User-operated audiometry was developed as an alternative to traditional audiometry for research purposes among musicians. Design: Test-retest reliability of the user-operated audiometry system was evaluated and the user-operated audiometry system was compared with traditional audiometry......Objective: To create a user-operated pure-tone audiometry method based on the method of maximum likelihood (MML) and the two-alternative forced-choice (2AFC) paradigm with high test-retest reliability without the need of an external operator and with minimal influence of subjects' fluctuating....... Study sample: Test-retest reliability of user-operated 2AFC audiometry was tested with 38 naïve listeners. User-operated 2AFC audiometry was compared to traditional audiometry in 41 subjects. Results: The repeatability of user-operated 2AFC audiometry was comparable to traditional audiometry...

  9. Multimodality evoked responses in the neurological assessment of the newborn. (United States)

    Mercuri, E; von Siebenthal, K; Daniëls, H; Guzzetta, F; Casaer, P


    In recent years increased attention has been devoted to evoked potentials (EP) in newborns. This paper reviews the literature and data from our research group in an attempt to assess the diagnostic and prognostic value of evoked responses in the first weeks of life and their use in different age-specific clinical conditions. The results show that EP are a very sensitive measure of the integrity of the sensory pathways. They make it possible to follow normal physiological maturation and the abnormalities of development resulting from neurological lesions. Repeated measurements of visual evoked potentials and somatosensorial evoked potential are prognostically useful in term infants, but seem much more limited in preterm newborns in predicting neurodevelopmental outcome.

  10. Occupational hearing loss: tonal audiometry X high frequencies audiometry

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    Lauris, José Roberto Pereira


    Full Text Available Introduction: Studies on the occupational exposure show that noise has been reaching a large part of the working population around the world, and NIHL (noise-induced hearing loss is the second most frequent disease of the hearing system. Objective: To review the audiometry results of employees at the campus of the University of São Paulo, Bauru. Method: 40 audiometry results were analyzed between 2007 and 2008, whose ages comprised between 32 and 59 years, of both sexes and several professions: gardeners, maintenance technicians, drivers etc. The participants were divided into 2 groups: those with tonal thresholds within acceptable thresholds and those who presented auditory thresholds alterations, that is tonal thresholds below 25 dB (NA in any frequency (Administrative Rule no. 19 of the Ministry of Labor 1998. In addition to the Conventional Audiologic Evaluation (250Hz to 8.000Hz we also carried out High Frequencies Audiometry (9000Hz, 10000Hz, 11200Hz, 12500Hz, 14000Hz and 16000Hz. Results: According to the classification proposed by FIORINI (1994, 25.0% (N=10 they presented with NIHL suggestive audiometric configurations. The results of high frequencies Audiometry confirmed worse thresholds than those obtained in the conventional audiometry in the 2 groups evaluated. Conclusion: The use of high frequencies audiometry proved to be an important register as a hearing alteration early detection method.

  11. Cortical Variability in the Sensory-Evoked Response in Autism (United States)

    Haigh, Sarah M.; Heeger, David J.; Dinstein, Ilan; Minshew, Nancy; Behrmann, Marlene


    Previous findings have shown that individuals with autism spectrum disorder (ASD) evince greater intra-individual variability (IIV) in their sensory-evoked fMRI responses compared to typical control participants. We explore the robustness of this finding with a new sample of high-functioning adults with autism. Participants were presented with…

  12. Visual field asymmetries in visual evoked responses. (United States)

    Hagler, Donald J


    Behavioral responses to visual stimuli exhibit visual field asymmetries, but cortical folding and the close proximity of visual cortical areas make electrophysiological comparisons between different stimulus locations problematic. Retinotopy-constrained source estimation (RCSE) uses distributed dipole models simultaneously constrained by multiple stimulus locations to provide separation between individual visual areas that is not possible with conventional source estimation methods. Magnetoencephalography and RCSE were used to estimate time courses of activity in V1, V2, V3, and V3A. Responses to left and right hemifield stimuli were not significantly different. Peak latencies for peripheral stimuli were significantly shorter than those for perifoveal stimuli in V1, V2, and V3A, likely related to the greater proportion of magnocellular input to V1 in the periphery. Consistent with previous results, sensor magnitudes for lower field stimuli were about twice as large as for upper field, which is only partially explained by the proximity to sensors for lower field cortical sources in V1, V2, and V3. V3A exhibited both latency and amplitude differences for upper and lower field responses. There were no differences for V3, consistent with previous suggestions that dorsal and ventral V3 are two halves of a single visual area, rather than distinct areas V3 and VP.

  13. Visual evoked responses during standing and walking

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    Klaus Gramann


    Full Text Available Human cognition has been shaped both by our body structure and by its complex interactionswith its environment. Our cognition is thus inextricably linked to our own and others’ motorbehavior. To model brain activity associated with natural cognition, we propose recording theconcurrent brain dynamics and body movements of human subjects performing normal actions.Here we tested the feasibility of such a mobile brain/body (MoBI imaging approach byrecording high-density electroencephalographic (EEG activity and body movements of subjectsstanding or walking on a treadmill while performing a visual oddball response task. Independentcomponent analysis (ICA of the EEG data revealed visual event-related potentials (ERPs thatduring standing, slow walking, and fast walking did not differ across movement conditions,demonstrating the viability of recording brain activity accompanying cognitive processes duringwhole body movement. Non-invasive and relatively low-cost MoBI studies of normal, motivatedactions might improve understanding of interactions between brain and body dynamics leadingto more complete biological models of cognition.

  14. Localizing evoked and induced responses to faces using magnetoencephalography. (United States)

    Perry, Gavin; Singh, Krish D


    A rich pattern of responses in frequency, time and space are known to be generated in the visual cortex in response to faces. Recently, a number of studies have used magnetoencephalography (MEG) to try to record these responses non-invasively - in many cases using source analysis techniques based on the beamforming method. Here we sought both to characterize best practice for measuring face-specific responses using MEG beamforming, and to determine whether the results produced by the beamformer match evidence from other modalities. We measured activity to visual presentation of face stimuli and phase-scrambled control stimuli, and performed source analyses of both induced and evoked responses using Synthetic Aperture Magnetometry. We localized the gamma-band response to bilateral lateral occipital cortex, and both the gamma-band response and the M170-evoked response to the right fusiform gyrus. Differences in the gamma-band response between faces and scrambled stimuli were confined to the frequency range 50-90 Hz; gamma-band activity at higher frequencies did not differ between the two stimulus categories. We additionally identified a component of the M220-evoked response - localized to the parieto-occipital sulcus - which was enhanced for scrambled vs. unscrambled faces. These findings help to establish that MEG beamforming can localize face-specific responses in time, frequency and space with good accuracy (when validated against established findings from functional magnetic resonance imaging and intracranial recordings), as well as contributing to the establishment of best methodological practice for the use of the beamformer method to measure face-specific responses.

  15. Test person operated 2-Alternative Forced Choice Audiometry compared to traditional audiometry

    DEFF Research Database (Denmark)

    Schmidt, Jesper Hvass; Brandt, Christian; Christensen-Dalsgaard, Jakob;

    as a comparison with traditional audiometry. A series of 30 persons (60 ears) have conducted traditional audiometry as well as self-operated 2AFC-audiometry. Test subjects are normal as well as moderately hearing impaired people. The different thresholds are compared.   Results: 2 AFC Audiometry is reliable...... and comparable to traditional audiometry. 2AFC audiometry tends to give thresholds 1-2 dB lower compared to traditional audiometry. In general standard deviations between the two test methods are below 4.5 dB for frequencies from (250-4000 Hz) and up to 6.7 dB for frequencies above 4000 Hz. Results from test......-retest studies of 2AFC audiometry are comparable to test-retest results known from traditional audiometry under standard clinical settings.   Conclusions 2 Alternative Forced Choice audiometry can be a reliable alternative to traditional audiometry especially under certain circumstances, where it can...

  16. Brain stem auditory evoked responses in chronic alcoholics.


    Chan, Y W; McLeod, J G; Tuck, R R; Feary, P A


    Brain stem auditory evoked responses (BAERs) were performed on 25 alcoholic patients with Wernicke-Korsakoff syndrome, 56 alcoholic patients without Wernicke-Korsakoff syndrome, 24 of whom had cerebellar ataxia, and 37 control subjects. Abnormal BAERs were found in 48% of patients with Wernicke-Korsakoff syndrome, in 25% of alcoholic patients without Wernicke-Korsakoff syndrome but with cerebellar ataxia, and in 13% of alcoholic patients without Wernicke-Korsakoff syndrome or ataxia. The mean...

  17. Pattern shift visual evoked response: application in neurology

    Directory of Open Access Journals (Sweden)

    Carlos A. M. Guerreiro


    Full Text Available The technique that we use for pattern shift visual evoked response (PSVER is described. PSVER is a non-invasive, practical and reliable clinical test in detecting anterior visual pathways lesions even when asymptomatic. The ability to find unsuspected lesions in multiple sclerosis, making possible an early diagnosis, is underscored. We also discuss some pathophysiologic aspects and the findings of the PSVER in some neurologic disorders with visual system involvement.

  18. Conditioning effect of transcranial magnetic stimulation evoking motor-evoked potential on V-wave response. (United States)

    Grosprêtre, Sidney; Martin, Alain


    The aim of this study was to examine the collision responsible for the volitional V-wave evoked by supramaximal electrical stimulation of the motor nerve during voluntary contraction. V-wave was conditioned by transcranial magnetic stimulation (TMS) over the motor cortex at several inter-stimuli intervals (ISI) during weak voluntary plantar flexions (n = 10) and at rest for flexor carpi radialis muscle (FCR; n = 6). Conditioning stimulations were induced by TMS with intensity eliciting maximal motor-evoked potential (MEPmax). ISIs used were ranging from -20 to +20 msec depending on muscles tested. The results showed that, for triceps surae muscles, conditioning TMS increased the V-wave amplitude (~ +250%) and the associated mechanical response (~ +30%) during weak voluntary plantar flexion (10% of the maximal voluntary contraction -MVC) for ISIs ranging from +6 to +18 msec. Similar effect was observed at rest for the FCR with ISI ranging from +6 to +12 msec. When the level of force was increased from 10 to 50% MVC or the conditioning TMS intensity was reduced to elicit responses of 50% of MEPmax, a significant decrease in the conditioned V-wave amplitude was observed for the triceps surae muscles, linearly correlated to the changes in MEP amplitude. The slope of this correlation, as well as the electro-mechanical efficiency, was closed to the identity line, indicating that V-wave impact at muscle level seems to be similar to the impact of cortical stimulation. All these results suggest that change in V-wave amplitude is a great index to reflect changes in cortical neural drive addressed to spinal motoneurons.

  19. Brain stem auditory evoked responses in human infants and adults (United States)

    Hecox, K.; Galambos, R.


    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  20. Averaged Electroencephalic Audiometry in Infants (United States)

    Lentz, William E.; McCandless, Geary A.


    Normal, preterm, and high-risk infants were tested at 1, 3, 6, and 12 months of age using averaged electroencephalic audiometry (AEA) to determine the usefulness of AEA as a measurement technique for assessing auditory acuity in infants, and to delineate some of the procedural and technical problems often encountered. (KW)

  1. Development of Brainstem-Evoked Responses in Congenital Auditory Deprivation

    Directory of Open Access Journals (Sweden)

    J. Tillein


    Full Text Available To compare the development of the auditory system in hearing and completely acoustically deprived animals, naive congenitally deaf white cats (CDCs and hearing controls (HCs were investigated at different developmental stages from birth till adulthood. The CDCs had no hearing experience before the acute experiment. In both groups of animals, responses to cochlear implant stimulation were acutely assessed. Electrically evoked auditory brainstem responses (E-ABRs were recorded with monopolar stimulation at different current levels. CDCs demonstrated extensive development of E-ABRs, from first signs of responses at postnatal (p.n. day 3 through appearance of all waves of brainstem response at day 8 p.n. to mature responses around day 90 p.n.. Wave I of E-ABRs could not be distinguished from the artifact in majority of CDCs, whereas in HCs, it was clearly separated from the stimulus artifact. Waves II, III, and IV demonstrated higher thresholds in CDCs, whereas this difference was not found for wave V. Amplitudes of wave III were significantly higher in HCs, whereas wave V amplitudes were significantly higher in CDCs. No differences in latencies were observed between the animal groups. These data demonstrate significant postnatal subcortical development in absence of hearing, and also divergent effects of deafness on early waves II–IV and wave V of the E-ABR.

  2. Postural threat influences vestibular-evoked muscular responses. (United States)

    Lim, Shannon B; Cleworth, Taylor W; Horslen, Brian C; Blouin, Jean-Sébastien; Inglis, J Timothy; Carpenter, Mark G


    Standing balance is significantly influenced by postural threat. While this effect has been well established, the underlying mechanisms of the effect are less understood. The involvement of the vestibular system is under current debate, and recent studies that investigated the effects of height-induced postural threat on vestibular-evoked responses provide conflicting results based on kinetic (Horslen BC, Dakin CJ, Inglis JT, Blouin JS, Carpenter MG. J Physiol 592: 3671-3685, 2014) and kinematic (Osler CJ, Tersteeg MC, Reynolds RF, Loram ID. Eur J Neurosci 38: 3239-3247, 2013) data. We examined the effect of threat of perturbation, a different form of postural threat, on coupling (cross-correlation, coherence, and gain) of the vestibulo-muscular relationship in 25 participants who maintained standing balance. In the "No-Threat" conditions, participants stood quietly on a stable surface. In the "Threat" condition, participants' balance was threatened with unpredictable mediolateral support surface tilts. Quiet standing immediately before the surface tilts was compared to an equivalent time from the No-Threat conditions. Surface EMG was recorded from bilateral trunk, hip, and leg muscles. Hip and leg muscles exhibited significant increases in peak cross-correlation amplitudes, coherence, and gain (1.23-2.66×) in the Threat condition compared with No-Threat conditions, and significant correlations were observed between threat-related changes in physiological arousal and medium-latency peak cross-correlation amplitude in medial gastrocnemius (r = 0.408) muscles. These findings show a clear threat effect on vestibular-evoked responses in muscles in the lower body, with less robust effects of threat on trunk muscles. Combined with previous work, the present results can provide insight into observed changes during balance control in threatening situations.

  3. Prestimulation phase predicts the TMS-evoked response. (United States)

    Kundu, Bornali; Johnson, Jeffrey S; Postle, Bradley R


    Prestimulation oscillatory phase and power in particular frequency bands predict perception of at-threshold visual stimuli and of transcranial magnetic stimulation (TMS)-induced phosphenes. These effects may be due to changes in cortical excitability, such that certain ranges of power and/or phase values result in a state in which a particular brain area is more receptive to input, thereby biasing behavior. However, the effects of trial-by-trial fluctuations in phase and power of ongoing oscillations on the brain's electrical response to TMS itself have thus far not been addressed. The present study adopts a combined TMS and electroencepalography (EEG) approach to determine whether the TMS-evoked response is sensitive to momentary fluctuations in prestimulation phase and/or power in different frequency bands. Specifically, TMS was applied to superior parietal lobule while subjects performed a short-term memory task. Results showed that the prestimulation phase, particularly within the beta (15-25 Hz) band, predicted pulse-by-pulse variations in the global mean field amplitude. No such relationship was observed between prestimulation power and the global mean field amplitude. Furthermore, TMS-evoked power in the beta band fluctuated with prestimulation phase in the beta band in a manner that differed from spontaneous brain activity. These effects were observed in areas at and distal to the stimulation site. Together, these results confirm the idea that fluctuating phase of ongoing neuronal oscillations create "windows of excitability" in the brain, and they give insight into how TMS interacts with ongoing brain activity on a pulse-by-pulse basis.

  4. Application of auditory brainstem response and pure tone audiometry in early diagnosis of acoustic neuroma%听性脑干反应和纯音听阈在听神经瘤早期诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    赵赋; 武丽; 王博; 杨智君; 王振民; 王兴朝; 李朋; 张晶; 刘丕楠


    目的 探讨采用听性脑干反应和纯音听阈对早期诊断听神经瘤的临床应用价值.方法 回顾性分析了111例听神经瘤患者的临床资料、纯音听阈、听性脑干反应及增强磁共振结果,采用线性回归分析纯音听阈均值与肿瘤体积、病程是否存在相关性,采用卡方检验分析不同肿瘤体积在听性脑干反应异常发生率上是否存在差异.结果 听神经瘤引起感音神经性耳聋,纯音听阈均值与病程存在显著地相关性(P=0.000);听性脑干反应诊断听神经瘤的敏感度和特异度分别为98.2%和93.6%,肿瘤最大径>3 cm与≤3 cm两组,在患侧和对侧Ⅲ~Ⅳ波间期异常发生率上,差异均具有统计学意义(P值分别为0.038和0.045).结论 听性脑干反应联合纯音测听是早期诊断听神经瘤的有效方法.%Objective To investigate the clinical application value of using auditory brainstem response and pure tone audiometry for early diagnosis of acoustic neuroma.Methods The clinical data,the results of pure tone audiometry,auditory brainstem response,and enhanced MRI in 111 patients with acoustic neuroma were analyzed retrospectively.Linear regression analysis was used to analyze the correlation between the nean value of pure tone audiometry and the neuroma volune or course of disease.Chi-squared test was used to analyze the whether there were differences in the different neuroma volumes on the incidence of abnormal auditory brainstem response.Results Acoustic neuroma caused sensorineural deafness.There was a significant correlation between the mean value of pure tone audiometry and the course of disease (P =0.000).The sensitivity and specificity of auditory brainstem response for the diagnosis of acoustic neuroma were 98.2% and 93.6% respectively.The maximum diameters of neuromas were divided into 2 groups:> 3 cm or ≤3 cm.There were significant differences on the abnormal incidence of the Ⅲ to Ⅴ wave intervals of the

  5. Transient visual evoked neuromagnetic responses: Identification of multiple sources

    Energy Technology Data Exchange (ETDEWEB)

    Aine, C.; George, J.; Medvick, P.; Flynn, E.; Bodis-Wollner, I.; Supek, S.


    Neuromagnetic measurements and associated modeling procedures must be able to resolve multiple sources in order to localize and accurately characterize the generators of visual evoked neuromagnetic activity. Workers have identified at least 11 areas in the macaque, throughout occipital, parietal, and temporal cortex, which are primarily or entirely visual in function. The surface area of the human occipital lobe is estimated to be 150--250cm. Primary visual cortex covers approximately 26cm/sup 2/ while secondary visual areas comprise the remaining area. For evoked response amplitudes typical of human MEG data, one report estimates that a two-dipole field may be statistically distinguishable from that of a single dipole when the separation is greater than 1--2 cm. Given the estimated expanse of cortex devoted to visual processes, along with this estimate of resolution limits it is likely that MEG can resolve sources associated with activity in multiple visual areas. Researchers have noted evidence for the existence of multiple sources when presenting visual stimuli in a half field; however, they did not attempt to localize them. We have examined numerous human MEG field patterns resulting from different visual field placements of a small sinusoidal grating which suggest the existence of multiple sources. The analyses we have utilized for resolving multiple sources in these studies differ depending on whether there was evidence of (1) synchronous activation of two spatially discrete sources or (2) two discrete asynchronous sources. In some cases we have observed field patterns which appear to be adequately explained by a single source changing its orientation and location across time. 4 refs., 2 figs.

  6. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. The objective of this study is to investigate the application of ear-EEG in objective audiometry....

  7. Objective Audiometry using Ear-EEG

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Kidmose, Preben

    life. Ear-EEG may therefore be an enabling technology for objective audiometry out of the clinic, allowing regularly fitting of the hearing aids to be made by the users in their everyday life environment. In this study we investigate the application of ear-EEG in objective audiometry....

  8. Facilitating neuronal connectivity analysis of evoked responses by exposing local activity with principal component analysis preprocessing: simulation of evoked MEG. (United States)

    Gao, Lin; Zhang, Tongsheng; Wang, Jue; Stephen, Julia


    When connectivity analysis is carried out for event related EEG and MEG, the presence of strong spatial correlations from spontaneous activity in background may mask the local neuronal evoked activity and lead to spurious connections. In this paper, we hypothesized PCA decomposition could be used to diminish the background activity and further improve the performance of connectivity analysis in event related experiments. The idea was tested using simulation, where we found that for the 306-channel Elekta Neuromag system, the first 4 PCs represent the dominant background activity, and the source connectivity pattern after preprocessing is consistent with the true connectivity pattern designed in the simulation. Improving signal to noise of the evoked responses by discarding the first few PCs demonstrates increased coherences at major physiological frequency bands when removing the first few PCs. Furthermore, the evoked information was maintained after PCA preprocessing. In conclusion, it is demonstrated that the first few PCs represent background activity, and PCA decomposition can be employed to remove it to expose the evoked activity for the channels under investigation. Therefore, PCA can be applied as a preprocessing approach to improve neuronal connectivity analysis for event related data.

  9. Somatosensory-evoked blink response: investigation of the physiological mechanisms. (United States)

    Miwa, H; Nohara, C; Hotta, M; Shimo, Y; Amemiya, K


    The somatosensory-evoked blink response (SBR) is a newly identified blink reflex elicited by electrical stimulation of peripheral nerves. The present study was performed to investigate the physiological mechanism underlying the SBR elicited by median nerve stimulation in normal subjects. The peripheral afferents responsible for the SBR included low-threshold cutaneous fibres. In the SBR-positive subjects, the late (R2) component of the blink reflex elicited by supraorbital nerve stimulation and the SBR facilitated each other when both responses were induced at the same time, but they each caused long-lasting inhibition in the other when one stimulus was given as a conditioning stimulus. The extent of inhibition was correlated with the size of the preceding SBR. In the SBR-negative subjects, simultaneous inhibition of R2 was observed when median nerve stimulation was applied as a conditioning stimulus. Brainstem excitability, as evaluated by blink-reflex recovery studies, did not differ between SBR-positive and SBR-negative subjects. Therefore, based on anatomical and physiological findings, it appears that the reflex pathways of the SBR and R2 converge within the brainstem and compete with each other, presumably by presynaptic inhibition at the premotor level, before entering the common blink-reflex pathway. The influence of median nerve stimulation upon tonic contraction of the orbicularis oculi muscle was studied to detect the latent SBR. There was not only a facilitatory period corresponding to the SBR but also an active inhibitory period (exteroceptive suppression), suggesting that the mechanism generating the SBR is not only influenced by blink-reflex volleys but also by active exteroceptive suppression. Thus, the SBR may appear as a result of integration of facilitatory and inhibitory mechanisms within the brainstem.

  10. Comparison Acoustically Evoked Short Latency Negative Response with Vestibular Evoked Myogenic Potential in Adults with Profound Hearing Loss

    Directory of Open Access Journals (Sweden)

    Maryam Ramezani


    Full Text Available Background and Aim: A negative deflection with a 3-4 ms latency period has been reported to exist within the auditory brainstem response of some patients with profound hearing loss following a strong acoustic stimulus. This deflection, namingly the n3 or the acoustically evoked short latency negative response is assumed to be a vestibular-evoked potential, especially of saccular origin. Since the myogenic potential is also saccular in origin, the purpose of the present study was to investigate the relationship between these two tests in adults with profound hearing loss.Methods: The present cross sectional study was performed on 20 profoundly deaf volunteers(39 ears who aged between 18-40 years old, randomly selected from available deaf adults in Tehran. The auditory brainstem response of all subjects was recorded following a 1000 Hz tone burst in 70-100dB nHL. Subjects were also tested for vestibular evoked myogenic potential.Results: Only 34 of 39 ears recorded myogenic potential that negative response was recorded in 27 of 34 ears with normal p13 and n23. In seven ears with normal p13 and n23, the negative response was absent. In 3 ears with no p13 and n23, the negative response was observed, and two none.Conclusion: In view of the high prevalance of the negative response in profoundly deaf ears with normal p13 and n23, it could be concluded that the negative response can be used when for any reason, it is not possible to record myogenic potential and be considered as a new test in vestibular test battery.

  11. Sensitivity of cortical auditory evoked potential detection for hearing-impaired infants in response to short speech sounds

    Directory of Open Access Journals (Sweden)

    Bram Van Dun


    Full Text Available

    Background: Cortical auditory evoked potentials (CAEPs are an emerging tool for hearing aid fitting evaluation in young children who cannot provide reliable behavioral feedback. It is therefore useful to determine the relationship between the sensation level of speech sounds and the detection sensitivity of CAEPs.

    Design and methods: Twenty-five sensorineurally hearing impaired infants with an age range of 8 to 30 months were tested once, 18 aided and 7 unaided. First, behavioral thresholds of speech stimuli /m/, /g/, and /t/ were determined using visual reinforcement orientation audiometry (VROA. Afterwards, the same speech stimuli were presented at 55, 65, and 75 dB SPL, and CAEP recordings were made. An automatic statistical detection paradigm was used for CAEP detection.

    Results: For sensation levels above 0, 10, and 20 dB respectively, detection sensitivities were equal to 72 ± 10, 75 ± 10, and 78 ± 12%. In 79% of the cases, automatic detection p-values became smaller when the sensation level was increased by 10 dB.

    Conclusions: The results of this study suggest that the presence or absence of CAEPs can provide some indication of the audibility of a speech sound for infants with sensorineural hearing loss. The detection of a CAEP provides confidence, to a degree commensurate with the detection probability, that the infant is detecting that sound at the level presented. When testing infants where the audibility of speech sounds has not been established behaviorally, the lack of a cortical response indicates the possibility, but by no means a certainty, that the sensation level is 10 dB or less.

  12. PC-based tele-audiometry. (United States)

    Choi, Jong Min; Lee, Haet Bit; Park, Cheol Soo; Oh, Seung Ha; Park, Kwang Suk


    A personal computer (PC)-based audiometer was developed for interactive remote audiometry. This paper describes a tele-audiometric system and evaluates the performance of the device when compared with conventional face-to-face audiometry. The tele-audiometric system is fully PC-based. A sound card featuring a high-quality digital-to-analog converter is used as a pure-tone generator. The audiometric programs were developed based on Microsoft Windows in order to maximize usability. Audiologists and their subjects can use the tele-audiometry system as one would utilize any PC application. A calibration procedure has been applied for the standardization of sound levels in the remote system. The performance of this system was evaluated by comparing PC-based audiometry with the conventional clinical audiometry system for 37 subjects. Also, performance of the PC-based system was evaluated during use at a remote site. The PC-based audiometry system estimated the audiometric threshold with an error of less than 2.3 dBSPL. Only 10.7% of the results exhibited an error greater than 5 dBSPL during use at a remote site. The PC-based tele-audiomerty showed acceptable results for use at a remote site. This PC-based system can be used effectively and easily in many locations that have Internet access but no local audiologists.

  13. Genetic effects on source level evoked and induced oscillatory brain responses in a visual oddball task. (United States)

    Antonakakis, Marios; Zervakis, Michalis; van Beijsterveldt, Catharina E M; Boomsma, Dorret I; De Geus, Eco J C; Micheloyannis, Sifis; Smit, Dirk J A


    Stimuli in simple oddball target detection paradigms cause evoked responses in brain potential. These responses are heritable traits, and potential endophenotypes for clinical phenotypes. These stimuli also cause responses in oscillatory activity, both evoked responses phase-locked to stimulus presentation and phase-independent induced responses. Here, we investigate whether phase-locked and phase-independent oscillatory responses are heritable traits. Oscillatory responses were examined in EEG recordings from 213 twin pairs (91 monozygotic and 122 dizygotic twins) performing a visual oddball task. After group Independent Component Analysis (group-ICA) and time-frequency decomposition, individual differences in evoked and induced oscillatory responses were compared between MZ and DZ twin pairs. Induced (phase-independent) oscillatory responses consistently showed the highest heritability (24-55%) compared to evoked (phase-locked) oscillatory responses and spectral energy, which revealed lower heritability at 1-35.6% and 4.5-32.3%, respectively. Since the phase-independent induced response encodes functional aspects of the brain response to target stimuli different from evoked responses, we conclude that the modulation of ongoing oscillatory activity may serve as an additional endophenotype for behavioral phenotypes and psychiatric genetics.


    The research attempts to bridge the existing gap between the naturalistic observations of sound communication in anurans and the anatomical and...principles by which information is processed within the intact animal. To this end, vocal behavior has been evoked from the males of laboratory colonies of...bullfrogs (Rana catesbeiana) in response to a restricted class of natural and synthetic sounds. The evoked vocal responses, having the signal

  15. Saturation thresholds of evoked neural and hemodynamic responses in awake and asleep rats (United States)

    Schei, Jennifer L.; Van Nortwick, Amy S.; Meighan, Peter C.; Rector, David M.


    Neural activation generates a hemodynamic response to the localized region replenishing nutrients to the area. Changes in vigilance state have been shown to alter the vascular response where the vascular response is muted during wake compared to quiet sleep. We tested the saturation thresholds of the neurovascular response in the auditory cortex during wake and sleep by chronically implanting rats with an EEG electrode, a light emitting diode (LED, 600 nm), and photodiode to simultaneously measure evoked response potentials (ERPs) and evoked hemodynamic responses. We stimulated the cortex with a single speaker click delivered at random intervals 2-13 s at varied stimulus intensities ranging from 45-80 dB. To further test the potential for activity related saturation, we sleep deprived animals for 2, 4, or 6 hours and recorded evoked responses during the first hour recovery period. With increasing stimulus intensity, integrated ERPs and evoked hemodynamic responses increased; however the hemodynamic response approached saturation limits at a lower stimulus intensity than the ERP. With longer periods of sleep deprivation, the integrated ERPs did not change but evoked hemodynamic responses decreased. There may be physical limits in cortical blood delivery and vascular compliance, and with extended periods of neural activity during wake, vessels may approach these limits.

  16. Auditory steady-state evoked response in diagnosing and evaluating hearing in infants

    Institute of Scientific and Technical Information of China (English)

    Fei Mai; Xiaozhuang Zhang; Qunxin Lai; Yanfei Wu; Nanping Liao; Yi Ye; Zhenghui Zhong


    BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to help the hearing diagnosis and rehabilitation of hearing and languaging following auditory screening.OBJECTIVE: To compare the response threshold of ASSR with auditory threshold of visual reinforcement audiometry (VRA) in infants failed in the hearing screening for investigating their hearing loss.DESIGN: A comparative observation.SETTINGS: Maternal and child health care hospitals of Guangdong province, Shunde city, Nanhai city and Huadu district.PARTICIPANTS: Totally 321 infants of 0-3 years undergoing ASSR test were selected from the Hearing Center of Guangdong Maternal and Child Health Care Hospital from January 2002 to December 2004.Informed consents were obtained from their guardians. There were 193 cases (60.2%) of 0-6 months, 31 cases (9.7%) of 7-12 months, 17 cases (5.3%) of 13-18 months, 14 cases (4.4%) of 19-24 months, 33 cases of 25-30 months, and 33 cases (10.2%) of 31-36 months.METHODS: ① The 321 infants failed in the hearing screening were tested under sleeping status, the ranges of response threshold distribution in ASSR of different frequencies were analyzed in each age group. ② The infants above 2 years old were also tested with VRA, and their response thresholds were compared between VRA and ASSR. ③ Evaluative standards: The response threshold was < 30 dB for normal hearing, 31-50 dB for mild hearing loss, 51-70 dB for moderate hearing loss, 71-90 dB for severe hearing loss, and > 91 dB for extremely severe hearing loss.MAIN OUTCOME MEASURES: ① ASSR results of the infants failed in the screening; ② Proportion of cases of each response threshold in each age group; ③ Comparison of ASSR response thresholds and VRA auditory thresholds in the infants of 2-3 years old.RESULTS: ①The response threshold was < 30 dB in 47

  17. [A minicomputer system that extracts evoked responses from the E.E.G]. (United States)

    Maraval, G; Pernier, J; Peronnet, F; Echallier, J F; Gerin, P; Maugiere, F


    EVøQ is a minicomputer system that enables one to extract average evoked responses from the E.E.G. from a large number of analog channels, and can, therefore, be oriented towards a topographic study of the responses. It allows high-frequency sampling of the signal, in order to make possible a study of the brain stem evoked responses. This system consists of three programs: a configuration-editor which allows a pre-configuration of several kinds of experiments; an acquisition program, of monitoring, calibration, signal processing and automatic control of the stimulators; finally, a management and processing program of the resulting files.


    Directory of Open Access Journals (Sweden)

    Slavco CADIEV


    Full Text Available The problem of early detection of children with sense of hearing is very complicate. If the damage of sense of hearing is not detected on time and if You don’t take adequate treatment, after seven year that is impossible. Audiometry is one step to reestablishment diagnostic with help of electronic technology.

  19. Amplitude and phase equalization of stimuli for click evoked auditory brainstem responses. (United States)

    Beutelmann, Rainer; Laumen, Geneviève; Tollin, Daniel; Klump, Georg M


    Although auditory brainstem responses (ABRs), the sound-evoked brain activity in response to transient sounds, are routinely measured in humans and animals there are often differences in ABR waveform morphology across studies. One possible reason may be the method of stimulus calibration. To explore this hypothesis, click-evoked ABRs were measured from seven ears in four Mongolian gerbils (Meriones unguiculatus) using three common spectrum calibration strategies: Minimum phase filter, linear phase filter, and no filter. The results show significantly higher ABR amplitude and signal-to-noise ratio, and better waveform resolution with the minimum phase filtered click than with the other strategies.

  20. The relevance of the high frequency audiometry in tinnitus patients with normal hearing in conventional pure-tone audiometry


    Veronika Vielsmeier; Astrid Lehner; Jürgen Strutz; Thomas Steffens; Kreuzer, Peter M; Martin Schecklmann; Michael Landgrebe; Berthold Langguth; Tobias Kleinjung


    Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical chara...

  1. Conventional Audiometry, Extended High-Frequency Audiometry, and DPOAE for Early Diagnosis of NIHL


    Mehrparvar, Amir Houshang; Mirmohammadi, Seyyed Jalil; Davari, Mohammad Hossein; MOSTAGHACI, Mehrdad; Mollasadeghi, Abolfazl; Bahaloo, Maryam; Hashemi, Seyyed Hesam


    Background: Noise most frequently affects hearing system, as it may typically cause a bilateral, progressive sensorineural hearing loss at high frequencies. Objectives: This study was designed to compare three different methods to evaluate noise-induced hearing loss (conventional audiometry, high-frequency audiometry, and distortion product otoacoustic emission). Material and Methods: This was a cross-sectional study. Data was analyzed by SPSS (ver. 19) using chi square, T test and repeated m...

  2. Inhibition of centrally-evoked pressor responses by neurohypophyseal peptides and their fragments

    NARCIS (Netherlands)

    Versteeg, C.A.M.; Bohus, B.; Jong, Wybren de


    Intracerebroventricular administration of fragments of [arginine8]-vasopressin (AVP) such as AVP1–6 and AVP7–9 attenuated the pressor response evoked by electrical stimulation of the mesencephalic reticular formation in urethane-anaesthetized rats. Oxytocin (OXT) and the fragment OXT7–9 were also ac

  3. Steady-state visual-evoked response to upright and inverted geometrical faces: a magnetoencephalography study. (United States)

    Tsuruhara, Aki; Inui, Koji; Kakigi, Ryusuke


    The face is one of the most important visual stimuli in human life, and inverted faces are known to elicit different brain responses than upright faces. This study analyzed steady-state visual-evoked magnetic fields (SSVEFs) in eleven healthy participants when they viewed upright and inverted geometrical faces presented at 6Hz. Steady-state visual-evoked responses are useful measurements and have the advantages of robustness and a high signal-to-noise ratio. Spectrum analysis revealed clear responses to both upright and inverted faces at the fundamental stimulation frequency (6 Hz) and harmonics, i.e. SSVEFs. No significant difference was observed in the SSVEF amplitude at 6 Hz between upright and inverted faces, which was different from the transient visual-evoked response, N170. On the other hand, SSVEFs were delayed with the inverted face in the right temporal area, which was similar to N170 and the results of previous steady-state visual-evoked potentials studies. These results suggest that different mechanisms underlie the larger amplitude and delayed latency observed with face inversion, though further studies are needed to fully elucidate these mechanisms. Our study revealed that SSVEFs, which have practical advantages for measurements, could provide novel findings in human face processing.

  4. Cortical evoked potentials in response to rapid balloon distension of the rectum and anal canal

    DEFF Research Database (Denmark)

    Haas, S; Brock, C; Krogh, K

    healthy women received 30 RBDs in the rectum and the anal canal at intensities corresponding to sensory and unpleasantness thresholds, and response was recorded as cortical evoked potentials (CEPs) in 64-channels. The anal canal stimulations at unpleasantness level were repeated after 4 min to test...... showed reproducibility with ICCs for all bands >0.8 and corresponding CVs potentials evoked from the anal canal are challenged by latency jitter likely related to variability in muscle tone due to the distensions. Using single-sweep analysis, anal CEPs proved...

  5. The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry

    Directory of Open Access Journals (Sweden)

    Veronika Vielsmeier


    Full Text Available Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz. Here we explored whether the results of the high frequency audiometry (>8 kHz provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. Subjects and Methods. From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. Results. Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. Conclusion. In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

  6. Fast corrective responses are evoked by perturbations approaching the natural variability of posture and movement tasks. (United States)

    Crevecoeur, F; Kurtzer, I; Scott, S H


    A wealth of studies highlight the importance of rapid corrective responses during voluntary motor tasks. These studies used relatively large perturbations to evoke robust muscle activity. Thus it remains unknown whether these corrective responses (latency 20-100 ms) are evoked at perturbation levels approaching the inherent variability of voluntary control. To fill this gap, we examined responses for large to small perturbations applied while participants either performed postural or reaching tasks. To address multijoint corrective responses, we induced various amounts of single-joint elbow motion with scaled amounts of combined elbow and shoulder torques. Indeed, such perturbations are known to elicit a response at the unstretched shoulder muscle, which reflects an internal model of arm intersegmental dynamics. Significant muscle responses were observed during both postural control and reaching, even when perturbation-related joint angle, velocity, and acceleration overlapped in distribution with deviations encountered in unperturbed trials. The response onsets were consistent across the explored range of perturbation loads, with short-latency onset for the muscles spanning the elbow joints (20-40 ms), and long-latency for shoulder muscles (onset > 45 ms). In addition, the evoked activity was strongly modulated by perturbation magnitude. These results suggest that multijoint responses are not specifically engaged to counter motor errors that exceed a certain threshold. Instead, we suggest that these corrective processes operate continuously during voluntary motor control.

  7. Temporal coupling between stimulus-evoked neural activity and hemodynamic responses from individual cortical columns

    Energy Technology Data Exchange (ETDEWEB)

    Bruyns-Haylett, Michael; Zheng Ying; Berwick, Jason; Jones, Myles [The Centre for Signal Processing in Neuroimaging and Systems Neuroscience (SPINSN), Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TP (United Kingdom)], E-mail:


    Using previously published data from the whisker barrel cortex of anesthetized rodents (Berwick et al 2008 J. Neurophysiol. 99 787-98) we investigated whether highly spatially localized stimulus-evoked cortical hemodynamics responses displayed a linear time-invariant (LTI) relationship with neural activity. Presentation of stimuli to individual whiskers of 2 s and 16 s durations produced hemodynamics and neural activity spatially localized to individual cortical columns. Two-dimensional optical imaging spectroscopy (2D-OIS) measured hemoglobin responses, while multi-laminar electrophysiology recorded neural activity. Hemoglobin responses to 2 s stimuli were deconvolved with underlying evoked neural activity to estimate impulse response functions which were then convolved with neural activity evoked by 16 s stimuli to generate predictions of hemodynamic responses. An LTI system more adequately described the temporal neuro-hemodynamics coupling relationship for these spatially localized sensory stimuli than in previous studies that activated the entire whisker cortex. An inability to predict the magnitude of an initial 'peak' in the total and oxy- hemoglobin responses was alleviated when excluding responses influenced by overlying arterial components. However, this did not improve estimation of the hemodynamic responses return to baseline post-stimulus cessation.

  8. A Pilot Study of Phase-Evoked Acoustic Responses From the Ears of Human Subjects

    DEFF Research Database (Denmark)

    Christensen, Anders Tornvig; Dewey, James; Dhar, Sumitrajit;


    Temporal properties of otoacoustic emissions (OAEs) are of interest as they help understand the dynamic behavior and spatial distribution of the generating mechanisms. In particular, the ringing behavior of responses to clicks and tone bursts have been investigated, and times of arrival and round...... within one, three and five periods of the stimulus-frequency every 64 ms (54 conditions). Using a combination of level and phase variation, emissions linked to any time-invariant nonlinearity could be extracted. Phase-evoked residual responses (PERRs) look like tone bursts with a phase......-shift in the middle. According to a 6-dB criterion on the signal-to-noise ratio, five/nine subjects had PERRs in more than 15/36 conditions, disregarding the 18 180-degree conditions which evoked only five responses in total. Across subjects and conditions, stimulus-frequency OAEs were present in 358/468 (76......%) measurements. 125 of those and six of those without SFOAEs had PERRs. The 120-degree conditions evoked more PERRs than the 90- and 180-degree conditions. One-kHz conditions evoked slightly more than 2-kHz conditions and many more than 500-Hz conditions. Furthermore, the prevalence decreases with lower stimulus...

  9. Modeling auditory evoked brainstem responses to transient stimuli

    DEFF Research Database (Denmark)

    Rønne, Filip Munch; Dau, Torsten; Harte, James;


    A quantitative model is presented that describes the formation of auditory brainstem responses (ABR) to tone pulses, clicks and rising chirps as a function of stimulation level. The model computes the convolution of the instantaneous discharge rates using the “humanized” nonlinear auditory-nerve ...

  10. Separation of multiple evoked responses using differential amplitude and latency variability


    Kevin H. Knuth; Truccolo, Wilson A.; Bressler, Steven L.; Ding, Mingzhou


    In neuroelectrophysiology one records electric potentials or magnetic fields generated by ensembles of synchronously active neurons in response to externally presented stimuli. These evoked responses are often produced by multiple generators in the presence of ongoing background activity. While source localization techniques or current source density estimation are usually used to identify generators, application of blind source separation techniques to obtain independent components has becom...

  11. A Comparison of Thresholds in Auditory Steady - State Response with Pure Tone Audiometry in Subjects with Normal Hearing and Those with Mild and Moderate Sensorineural Hearing los

    Directory of Open Access Journals (Sweden)

    Sadegh Jafarzadeh


    Full Text Available Background and Aim: Among all auditory assessment tools, auditory steady state response (ASSR is a modern test. Modulation frequency for this test is usually 80 Hz. The purpose of this study, was to examined adult subjects with 40 Hz and 80 Hz ASSR and compare the results.Materials and Methods: Thirty adult (60 ears were evaluated by ASSR and PTA test, Results were divided into three groups: normal hearing, mild and moderate sensorineural hearing loss. Results: In all groups, forty hertz ASSR thresholds were relatively closer to behavioral threshold than those of 80 Hz ASSR(p<0.05. Besides, the more severe hearing loss, the lower the difference between those two thresholds. Correlation coefficients were also higher in 40 Hz ASSR(p<0.05. Conclusion: Frequency modulation thresholds with 40 Hz are more likely to be closer to the behavioral thresholds. Moreover, it has better results than the thresholds with 80 Hz.

  12. Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response. (United States)

    Osler, Callum J; Tersteeg, M C A; Reynolds, Raymond F; Loram, Ian D


    Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance.

  13. Identification Audiometry in an Institutionalized Severely and Profoundly Mentally Retarded Population. (United States)

    Moore, Ernest J.; And Others

    An audiometric screening survey was conducted on a severely and profoundly mentally retarded population using noise-makers and pure tone audiometry. Of those tested with noise-makers, 83% gave an identifiable response to sound, 7% did not respond, and 10% were considered difficult-to-test. By contrast, 4% passed, 2% failed, and 94% were…

  14. Is the auditory evoked P2 response a biomarker of learning?

    Directory of Open Access Journals (Sweden)

    Kelly eTremblay


    Full Text Available Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography and magnetoencephalography have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP, as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What’s more, these effects were retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN wave 600-900 ms post-stimulus onset, post-training, exclusively for the group that learned to identify the pre

  15. Is the auditory evoked P2 response a biomarker of learning? (United States)

    Tremblay, Kelly L; Ross, Bernhard; Inoue, Kayo; McClannahan, Katrina; Collet, Gregory


    Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography (EEG) and magnetoencephalography (MEG) have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP), as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What's more, these effects are retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN) wave 600-900 ms post-stimulus onset, post-training exclusively for the group that learned to identify the pre-voiced contrast.

  16. Visual Evoked Responses and EEGS for Divers Breathing Hyperbaric Air: An Assessment of Individual Differences (United States)


    PAGE THE PROBLEM To find and assess quantitatively electrophysiologieal corre- lates of nitrogen narcosis in divers. FINDINGS Marked decrements in...visual evoked responses were found in most divers under conditions conducive to nitrogen narcosis . Results of this study show the average sizes of...the decrements and their probability of occurrence in a large group of subjects. APPLICATION Since nitrogen narcosis is a major problem deterring air

  17. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat (United States)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.


    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  18. Mechanism of action of magnesium on acetylcholine-evoked secretory responses in isolated rat pancreas. (United States)

    Francis, L P; Lennard, R; Singh, J


    This study investigates the effects of magnesium (Mg2+) on acetylcholine (ACh)-evoked secretory responses and calcium (Ca2+) mobilization in the isolated rat pancreas. ACh induced marked dose-dependent increases in total protein output and amylase release from superfused pancreatic segments in zero, normal (1 x 1 mM) and elevated (10 mM) extracellular Mg2+. Elevated Mg2+ attenuated the ACh-evoked secretory responses compared to zero and normal Mg2+. In the absence of extracellular Ca2+, but presence of 1 mM-EGTA (ethylene glycol bis(beta-aminoethylether)-N,N,N',N''-tetraacetic acid), ACh elicited a small transient release of protein from pancreatic segments compared to a larger and more sustained secretion in the absence of both Ca2+ and Mg2+. Incubation of pancreatic segments with 45Ca2+ resulted in time-dependent uptake with maximum influx of 45Ca2+ occurring after 20 min of incubation period. ACh stimulated markedly the 45Ca2+ uptake compared to control tissues. In elevated extracellular Mg2+ the ACh-induced 45Ca2+ influx was significantly (P less than 0.001) reduced compared to zero and normal Mg2+. ACh also evoked dose-dependent increases in cytosolic free Ca2+ concentrations ([Ca2+]i) in pancreatic acinar cells loaded with the fluorescent dye Fura-2 AM. In elevated Mg2+ the ACh-induced cytosolic [Ca2+]i was significantly (P less than 0.001) reduced compared to zero and normal Mg2+. These results indicate that Mg2+ can influence ACh-evoked secretory responses possibly by controlling both Ca2+ influx and release in pancreatic acinar cells.

  19. Comparing the Performance of Popular MEG/EEG Artifact Correction Methods in an Evoked-Response Study

    DEFF Research Database (Denmark)

    Haumann, Niels Trusbak; Parkkonen, Lauri; Kliuchko, Marina;


    We here compared results achieved by applying popular methods for reducing artifacts in magnetoencephalography (MEG) and electroencephalography (EEG) recordings of the auditory evoked Mismatch Negativity (MMN) responses in healthy adult subjects. We compared the Signal Space Separation (SSS) and ...

  20. [Visual evoked responses with flash pattern in normal subjects (author's transl)]. (United States)

    Samson-Dollfus, D; Parain, D; Mihout, B; Menard, J F; Weber, J; Neheli, F


    Visual evoked responses to flash pattern simulations have been observed in young healthy adults. Stimulations of whole visual fields (37 subjects) and half-fields (11 subjects) have been performed. These responses are reproductible from one subject to another and show very clear waves in the occipital and central regions. On central leads, whatever the stimulation (stimulation of total visual fields or half-fields), the responses are always the same: a negative peak at 70 msec. followed by a positive peak at 90 msec, then a negative peak at 116-120 msec. On occipital leads, stimulation of the whole visual field shows a diphasic response: a positive wave at 100 msec and a negative wave at 140-150 msec. However, half-field stimulation shows different responses on the ipsi- and contralateral hemispheres, with a disappearance of the positive 100 msec wave in the ipsilateral occipital region. Thus, flash pattern stimulations seem to be useful in clinical practice because they evoke different types of responses in occipital and central regions.

  1. Brain-stem auditory evoked responses during microvascular decompression for trigeminal neuralgia: Predicting post-operative hearing loss

    Directory of Open Access Journals (Sweden)

    Ramnarayan Ramachandran


    Full Text Available Context: The importance of brainstem auditory evoked potential monitoring in reducing hearing loss during microvascular decompression for trigeminal neuralgia is now accepted. However the extent of the changes in the pattern of these potentials and the safe limits to which these changes are relevant in reducing postoperative hearing loss have not been established. Aims: The aim of this study is to quantify these changes and relate these to the postoperative hearing loss. Settings and Design: This study was done at the Walton Centre for neurology and neurosurgery, Liverpool, United Kingdom. The study was designed to give a measure of the change in the wave pattern following microvascular decompression and relate it to postoperative hearing loss. Materials and Methods: Seventy-five patients undergoing microvascular decompression for trigeminal neuralgia had preoperative and postoperative hearing assessments and intraoperative brainstem auditory evoked potential monitoring. Statistical Analysis Used: Chi-square tests. Results: It was found that the wave V latency was increased by more than 0.9ms in nine patients, eight of whom suffered significant postoperative hearing loss as demonstrated by audiometry. It was also seen that progressive decrease in amplitude of wave V showed progressive hearing loss with 25% loss when amplitude fell by 50 and 100% loss when wave V was lost completely. However most of the patients did not have a clinically manifest hearing loss. Conclusions: A per-operative increase in the latency of wave V greater than 0.9 ms and a fall of amplitude of wave V of more than 50% indicates a risk to hearing.

  2. Electrophysiological Techniques for Sea Lion Population-Level Audiometry (United States)


    Audiometry James J. Finneran Space and Naval Warfare Systems Center Pacific, Biosciences Division, Code 71510, 53560 Hull Street, San Diego, CA...DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Electrophysiological Techniques For Sea Lion Population-Level Audiometry 5a

  3. Collection and analysis of offshore workforce audiometry data

    Energy Technology Data Exchange (ETDEWEB)



    This report summarises the results of a study analysing audiometry data to determine if noise induced related hearing loss is happening in offshore operations. The background to the study is traced, and details are given of the initial contacts with medical and operational companies holding audiometry data, the confidentiality of the data sources, the questionnaire for the holders of personnel audiometry data, and initial data checking. A descriptive analysis of the study population is presented, and the analysis of audiometry data, hearing threshold levels, and the classification of the data using the Health and Safety Executive (HSE) categorisation scheme are discussed. The questionnaire for the data holders, the audiometry data collection proforma, and guidance for completion of data collection proformas are included in appendices.

  4. Adaptive Fourier series modeling of time-varying evoked potentials: study of human somatosensory evoked response to etomidate anesthetic. (United States)

    Thakor, N V; Vaz, C A; McPherson, R W; Hanley, D F


    Evoked potentials (EPs) have traditionally been analyzed in time domain, with amplitude and latency of various signal components used in clinical interpretation. A new approach, called adaptive Fourier series modeling (FSM), is presented here. Dynamic changes in magnitudes of Fourier coefficients are analyzed for diagnostic purposes. In order to estimate the time-varying changes in the Fourier coefficients of noisy signals, a least mean-square filtering algorithm is applied. Results of computer simulations as well as experimental data are presented. Time-varying trends are presented in a new compressed evoked spectrum format. These techniques are applied to the study of alterations in human somatosensory EPs caused by the intravenous administration of etomidate during neurosurgical procedures. Amplitude increases of the order of 200-500% occurring within a time span of about 100 sec were captured. Due to its superior convergence properties, the adaptive FSM technique estimates more rapid changes in amplitude and latency than exponentially weighted averaging or moving window averaging schemes.

  5. Cell-attached recordings of responses evoked by photorelease of GABA in the immature cortical neurons

    Directory of Open Access Journals (Sweden)

    Marat eMinlebaev


    Full Text Available We present a novel non-invasive technique to measure the polarity of GABAergic responses based on cell-attached recordings of currents activated by laser-uncaging of GABA. For these recordings, a patch pipette was filled with a solution containing RuBi-GABA, and GABA was released from this complex by a laser beam conducted to the tip of the patch pipette via an optic fiber. In cell-attached recordings from neocortical and hippocampal neurons in postnatal days P2-5 rat brain slices in vitro, we found that laser-uncaging of GABA activates integral cell-attached currents mediated by tens of GABA(A channels. The initial response was inwardly directed, indicating a depolarizing response to GABA. The direction of the initial response was dependent on the pipette potential and analysis of its slope-voltage relationships revealed a depolarizing driving force of +11 mV for the currents through GABA channels. Initial depolarizing responses to GABA uncaging were inverted to hyperpolarizing in the presence of the NKCC1 blocker bumetanide. Current-voltage relationships of the currents evoked by Rubi-GABA uncaging using voltage-ramps at the peak of responses not only revealed a bumetanide-sensitive depolarizing reversal potential of the GABA(A receptor mediated responses, but also showed a strong voltage-dependent hysteresis. Upon desensitization of the uncaged-GABA response, current-voltage relationships of the currents through single GABA(A channels revealed depolarizing responses with the driving force values similar to those obtained for the initial response. Thus, cell-attached recordings of the responses evoked by local intrapipette GABA uncaging are suitable to assess the polarity of the GABA(A-Rs mediated signals in small cell compartments.

  6. Brainstem auditory-evoked responses with and without sedation in autism and Down's syndrome. (United States)

    Sersen, E A; Heaney, G; Clausen, J; Belser, R; Rainbow, S


    Brainstem auditory-evoked responses (BAER) were obtained from 46 control, 16 Down's syndrome, and 48 autistic male subjects. Six Down's syndrome and 37 autistic subjects were tested with sedation. Sedated and unsedated Down's syndrome subjects displayed shorter absolute and interpeak latencies for early components of the BAER whereas the sedated autistic group showed longer latencies for the middle and late components. The prolongation of latencies in the sedated autistic group was unrelated to age or intellectual level. Although individuals requiring sedation may have a higher probability of neurological impairment, an effect of sedation on the BAER cannot be ruled out.

  7. Sympathetic skin responses from the scalp evoked by electrical stimulation in seborrheic dermatitis. (United States)

    Altunrende, Burcu; Yildiz, Serpil; Kandi, Basak; Yildiz, Nebil


    Although the role of autonomic nervous system in seborrheic dermatitis (SD) is still unclear, seborrhea is sometimes accepted as a sign of autonomic dysfunction in several nervous system diseases. Therefore, we aimed to investigate the sympathetic nervous system (SNS) activity in SD by recording sympathetic skin responses (SSR) from the scalp (S-SSR). Thirty-one control subjects and 22 SD patients were studied by evoking right and left S-SSR with electrical stimulation of the right median nerve at the wrist. Mean latencies and maximum amplitudes were calculated for both sides in each group. In seven out of 31 control subjects and in 13 out of 22 patients, the S-SSR could not be elicited on either side. There were four subjects with unilateral response in the patient group. There were significantly more non-responders among the patients with SD (P < 0.000). This study suggests that in SD, the autonomic nervous system may be involved. The S-SSR is a new site for recording SSR. The responses are relatively symmetrical and can be evoked easily by electrical stimulation, and may be used to evaluate the SNS function in SD patients and also in healthy subjects.

  8. Ileal interposition attenuates the satiety responses evoked by cholecystokinin-8 and -33. (United States)

    Metcalf, Shannon A; Washington, Martha C; Brown, Thelma A L; Williams, Carol S; Strader, April D; Sayegh, Ayman I


    One of the possible mechanisms by which the weight-reducing surgical procedure ileal interposition (II) works is by increasing circulating levels of lower gut peptides that reduce food intake, such as glucagon like peptide-1 and peptide YY. However, since this surgery involves both lower and upper gut segments, we tested the hypothesis that II alters the satiety responses evoked by the classic upper gut peptide cholecystokinin (CCK). To test this hypothesis, we determined meal size (MS), intermeal interval (IMI) and satiety ratio (SR) evoked by CCK-8 and -33 (0, 1, 3, 5nmol/kg, i.p.) in two groups of rats, II and sham-operated. CCK-8 and -33 reduced MS more in the sham group than in the II group; CCK-33 prolonged IMI in the sham group and increased SR in both groups. Reduction of cumulative food intake by CCK-8 in II rats was blocked by devazepide, a CCK(1) receptor antagonist. In addition, as previously reported, we found that II resulted in a slight reduction in body weight compared to sham-operated rats. Based on these observations, we conclude that ileal interposition attenuates the satiety responses of CCK. Therefore, it is unlikely that this peptide plays a significant role in reduction of body weight by this surgery.

  9. Effect of nitrogen narcosis on cortical and subcortical evoked responses in the cat. (United States)

    Bartus, R T; Kinney, J S


    Four cats were chronically implanted with gross, monopolar electrodes in the lateral geniculate nucleus (LGN), pretectum-superior colliculus (P-SC), primary visual cortex (VI), and secondary visual cortex (VII). Following recovery and preliminary testing, the animals were dived in a dry hyperbaric chamber to the sea water equivalent of 103 m (i.e. 340 ft.) where visual evoked responses were recorded. No decrements in the amplitude of the visual evoked response were found at the LGN, but significant decreases did occur at the other three sites. These data suggested: 1) that the effects of nitrogen narcosis on the visual system are primarily central, and not simply peripheral in nature; 2) that these effects are not limited to the visual cortical mantle; and 3) that the narcosis apparently influences structures involving different anatomical levels of the brain which presumably mediate various types of visual processes. The findings were discussed as they relate to current ideas concerning the underlying neurological causes and behavioral effects of nitrogen narcosis.

  10. The stimulus-evoked population response in visual cortex of awake monkey is a propagating wave. (United States)

    Muller, Lyle; Reynaud, Alexandre; Chavane, Frédéric; Destexhe, Alain


    Propagating waves occur in many excitable media and were recently found in neural systems from retina to neocortex. While propagating waves are clearly present under anaesthesia, whether they also appear during awake and conscious states remains unclear. One possibility is that these waves are systematically missed in trial-averaged data, due to variability. Here we present a method for detecting propagating waves in noisy multichannel recordings. Applying this method to single-trial voltage-sensitive dye imaging data, we show that the stimulus-evoked population response in primary visual cortex of the awake monkey propagates as a travelling wave, with consistent dynamics across trials. A network model suggests that this reliability is the hallmark of the horizontal fibre network of superficial cortical layers. Propagating waves with similar properties occur independently in secondary visual cortex, but maintain precise phase relations with the waves in primary visual cortex. These results show that, in response to a visual stimulus, propagating waves are systematically evoked in several visual areas, generating a consistent spatiotemporal frame for further neuronal interactions.

  11. Population response propagation to extrastriate areas evoked by intracortical electrical stimulation in V1

    Directory of Open Access Journals (Sweden)

    Tamas David Fehervari


    Full Text Available The mouse visual system has multiple extrastriate areas surrounding V1 each with a distinct representation of the visual field and unique functional and connectivity profiles, which are believed to form two parallel processing streams, similar to the ventral and dorsal streams in primates. At the same time, mouse visual areas have a high degree of interconnectivity, in particular V1 sends input to all higher visual areas. The study of these direct connections can further our understanding of the cortical processing of visual signals in the early mammalian cortex. Several studies have been published about the anatomy of these connections, but an in vivo electrophysiological characterization and comparison of the transmission to multiple extrastriate areas has not yet been reported. We used intracortical electrical stimulation combined with RH1691 VSD imaging in adult C57BL/6 mice in urethane anesthesia to analyze interareal transmission from V1 to extrastriate areas in superficial cortical layers. We found 7 extrastriate response sites (5 lateral, 2 medial in a spatial pattern similar to area maps of the mouse visual cortex and, by shifting the location of V1 stimulation, demonstrated that the evoked responses in LM and AL were in accordance with the visuotopic mappings of these areas known from anatomy and in vivo studies. These two sites, considered to be gateways to their processing streams, had shorter latencies and faster transmission speeds than other extrastriate response sites. Short latency differences between response sites, and that TTX injection into LM reduced but did not eliminate other extrastriate responses indicated that the evoked cortical activity was, at least partially, transmitted directly from V1 to extrastriate areas. This study reports on analysis of interareal transmission from V1 to multiple extrastriate areas in mouse using intracortical electrical stimulation in vivo.

  12. Exploring the variability of single trials in somatosensory evoked responses using constrained source extraction and RMT. (United States)

    Koutras, A; Kostopoulos, G K; Ioannides, A A


    This paper describes the theoretical background of a new data-driven approach to encephalographic single-trial (ST) data analysis. Temporal constrained source extraction using sparse decomposition identifies signal topographies that closely match the shape characteristics of a reference signal, one response for each ST. The correlations between these ST topographies are computed for formal Correlation Matrix Analysis (CMA) based on Random Matrix Theory (RMT). The RMT-CMA provides clusters of similar ST topologies in a completely unsupervised manner. These patterns are then classified into deterministic set and noise using well established RMT results. The efficacy of the method is applied to EEG and MEG data of somatosensory evoked responses (SERs). The results demonstrate that the method can recover brain signals with time course resembling the reference signal and follow changes in strength and/or topography in time by simply stepping the reference signal through time.

  13. Cortical evoked potentials in response to rapid balloon distension of the rectum and anal canal

    DEFF Research Database (Denmark)

    Haas, S; Brock, C; Krogh, K;


    BACKGROUND: Neurophysiological evaluation of anorectal sensory function is hampered by a paucity of methods. Rapid balloon distension (RBD) has been introduced to describe the cerebral response to rectal distension, but it has not successfully been applied to the anal canal. METHODS: Nineteen...... healthy women received 30 RBDs in the rectum and the anal canal at intensities corresponding to sensory and unpleasantness thresholds, and response was recorded as cortical evoked potentials (CEPs) in 64-channels. The anal canal stimulations at unpleasantness level were repeated after 4 min to test...... the within-day reproducibility. CEPs were averaged, and to overcome latency variation related to jitter the spectral content of single sweeps was also computed. KEY RESULTS: Repeated stimulation of the anal canal generated CEPs with similar latencies but smaller amplitudes compared to those from the rectum...

  14. Aberrant lateralization of brainstem auditory evoked responses by individuals with Down syndrome. (United States)

    Miezejeski, C M; Heaney, G; Belser, R; Sersen, E A


    Brainstem auditory evoked response latencies were studied in 80 males (13 with Down syndrome, 23 with developmental disability due to other causes, and 44 with no disability). Latencies for waves P3 and P5 were shorter for the Down syndrome than for the other groups, though at P5, as compared to latencies for the nondisabled group, the difference was not significant. The pattern of left versus right ear responses in the Down syndrome group differed from those of the other groups. This finding was related to research noting decreased lateralization of and decreased ability at receptive and expressive language among people with Down syndrome. Some individuals required sedation. A lateralized effect of sedation was noted.

  15. Stimulus-response characteristics of motor evoked potentials and silent periods in proximal and distal upper-extremity muscles.

    NARCIS (Netherlands)

    Kuijk, A.A. van; Anker, L.C.; Pasman, J.W.; Hendriks, J.C.M.; Elswijk, G.A.F. van; Geurts, A.C.H.


    OBJECTIVE: To compare stimulus-response characteristics of both motor evoked potentials (MEP) and silent periods (SP) induced by transcranial magnetic stimulation (TMS) in proximal and distal upper-extremity muscles. METHODS: Stimulus-response curves of MEPs and SPs were obtained from the biceps bra

  16. Frequency characteristics of human muscle and cortical responses evoked by noisy Achilles tendon vibration. (United States)

    Mildren, Robyn Lynne; Peters, Ryan M; Hill, Aimee J; Blouin, Jean-Sebastien; Carpenter, Mark Gregory; Inglis, J Timothy


    Noisy stimuli, along with linear systems analysis, have proven to be effective for mapping functional neural connections. We explored the use of noisy (10-115 Hz) Achilles tendon vibration to examine proprioceptive reflexes in the triceps surae muscles in standing healthy young adults (n = 8). We also examined the association between noisy vibration and electrical activity recorded over the sensorimotor cortex using electroencephalography. We applied two-minutes of vibration and recorded ongoing muscle activity of the soleus and gastrocnemii using surface electromyography (EMG). Vibration amplitude was varied to characterize reflex scaling and to examine how different stimulus levels affected postural sway. Muscle activity from the soleus and gastrocnemii were significantly correlated with the tendon vibration across a broad frequency range (~10-80 Hz), with a peak located at ~40 Hz. Vibration-EMG coherence positively scaled with stimulus amplitude in all three muscles, with soleus displaying the strongest coupling and steepest scaling. EMG responses lagged the vibration by ~38 ms, a delay that paralleled observed response latencies to tendon taps. Vibration-evoked cortical oscillations were observed at frequencies ~40-70 Hz (peak ~54 Hz) in most subjects, a finding in line with previous reports of sensory evoked γ-band oscillations. Further examination of the method revealed a) accurate reflex estimates could be obtained with <60 s of low-level (RMS=10 m/s(2)) vibration, b) responses did not habituate over two-minutes of exposure, and importantly c) noisy vibration had a minimal influence on standing balance. Our findings suggest noisy tendon vibration is an effective novel approach to characterize proprioceptive reflexes.

  17. Modulation of visually evoked postural responses by contextual visual, haptic and auditory information: a 'virtual reality check'.

    Directory of Open Access Journals (Sweden)

    Georg F Meyer

    Full Text Available Externally generated visual motion signals can cause the illusion of self-motion in space (vection and corresponding visually evoked postural responses (VEPR. These VEPRs are not simple responses to optokinetic stimulation, but are modulated by the configuration of the environment. The aim of this paper is to explore what factors modulate VEPRs in a high quality virtual reality (VR environment where real and virtual foreground objects served as static visual, auditory and haptic reference points. Data from four experiments on visually evoked postural responses show that: 1 visually evoked postural sway in the lateral direction is modulated by the presence of static anchor points that can be haptic, visual and auditory reference signals; 2 real objects and their matching virtual reality representations as visual anchors have different effects on postural sway; 3 visual motion in the anterior-posterior plane induces robust postural responses that are not modulated by the presence of reference signals or the reality of objects that can serve as visual anchors in the scene. We conclude that automatic postural responses for laterally moving visual stimuli are strongly influenced by the configuration and interpretation of the environment and draw on multisensory representations. Different postural responses were observed for real and virtual visual reference objects. On the basis that automatic visually evoked postural responses in high fidelity virtual environments should mimic those seen in real situations we propose to use the observed effect as a robust objective test for presence and fidelity in VR.

  18. Effects of intraocular mescaline and LSD on visual-evoked responses in the rat. (United States)

    Eells, J T; Wilkison, D M


    The effects of mescaline and LSD on the flash-evoked cortical potential (FEP) were determined in unrestrained rats with chronically-implanted electrodes. Systemic administration of mescaline or LSD significantly attenuated the primary component of the FEP at three stimulus intensities with the greatest effect observed 60-90 minutes following drug administration. The magnitude and specificity of the effects of these agents on the primary response suggest that they produce deficits in conduction through the retino-geniculato-cortical system. The serotonin receptor antagonists, cyproheptadine and methysergide, antagonized the mescaline-induced depression of the FEP in accordance with neurochemical and behavioral evidence that mescaline acts as a partial agonist on serotonin receptors. Topical or intraocular administration of atropine antagonized the actions of systemically-administered mescaline. In addition, intraocular administration of mescaline or LSD attenuated the FEP indicative of an action of these hallucinogens on visual processing in the retina which is modulated by muscarinic receptor activity.

  19. Habituation of evoked responses is greater in patients with familial hemiplegic migraine than in controls

    DEFF Research Database (Denmark)

    Hansen, Jakob Møller; Bolla, M; Magis, D;


    been attributed to neuronal dysexcitability. FHM and the common forms of migraine are thought to belong to a spectrum of migraine phenotypes with similar pathophysiology, and we therefore examined whether an abnormal habituation pattern would also be found in FHM patients.......Familial hemiplegic migraine (FHM) is a rare, dominantly inherited subtype of migraine with transient hemiplegia during the aura phase. Mutations in at least three different genes can produce the FHM phenotype. The mutated FHM genes code for ion transport proteins that animal and cellular studies...... have associated with disturbed ion homeostasis, altered cellular excitability, neurotransmitter release, and decreased threshold for cortical spreading depression. The common forms of migraine are characterized interictally by a habituation deficit of cortical and subcortical evoked responses that has...

  20. Habituation of single CO2 laser-evoked responses during interictal phase of migraine. (United States)

    de Tommaso, Marina; Libro, Giuseppe; Guido, Marco; Losito, Luciana; Lamberti, Paolo; Livrea, Paolo


    A reduced habituation of averaged laser-evoked potential (LEP) amplitudes was previously found in migraine patients. The aim of the present study was to assess the habituation of single LEP responses and pain sensation during the interictal phase in migraine patients. Fourteen migraine patients were compared with ten control subjects. The pain stimulus was laser pulses, generated by CO2 laser, delivered to right supraorbital zone. Patients were evaluated during attack-free conditions. The LEP habituation was studied by measuring the changes of LEP amplitudes across and within three consecutive repetitions of 21 non-averaged trials. In migraine patients the N2-P2 wave amplitudes did not show a tendency toward habituation across and, above all, within the three repetitions. Anomalous behaviour of nociceptive cortex during the interictal phase of migraine may predispose patients to headache occurrence and persistence.

  1. Longer brainstem auditory evoked response latencies of individuals with fragile X syndrome related to sedation. (United States)

    Miezejeski, C M; Heaney, G; Belser, R; Brown, W T; Jenkins, E C; Sersen, E A


    Brainstem auditory evoked response latencies were studies in 75 males (13 with fragile X syndrome, 18 with mental retardation due to other causes, and 44 with no disability). Latency values were obtained for each ear for the positive deflections of waves I (P1), III (P3), and V (P5). Some individuals with mental retardation required sedation. Contrary to previous report, latencies obtained for individuals with fragile X did not differ from those obtained for persons without mental retardation. Persons receiving sedation, whether or not their retardation was due to fragile X, had longer latencies for wave P5 than persons who did not receive sedation. This effect of sedation may also explain the previously reported increased latencies for persons with fragile X.

  2. Rate and adaptation effects on the auditory evoked brainstem response in human newborns and adults. (United States)

    Lasky, R E


    Auditory evoked brainstem response (ABR) latencies increased and amplitudes decreased with increasing stimulus repetition rate for human newborns and adults. The wave V latency increases were larger for newborns than adults. The wave V amplitude decreases were smaller for newborns than adults. These differences could not be explained by developmental differences in frequency responsivity. The transition from the unadapted to the fully adapted response was less rapid in newborns than adults at short (= 10 ms) inter stimulus intervals (ISIs). At longer ISIs (= 20 ms) there were no developmental differences in the transition to the fully adapted response. The newborn transition occurred in a two stage process. The rapid initial stage observed in adults and newborns was complete by about 40 ms. A second slower stage was observed only in newborns although it has been observed in adults in other studies (Weatherby and Hecox, 1982; Lightfoot, 1991; Lasky et al., 1996). These effects were replicated at different stimulus intensities. After the termination of stimulation the return to the wave V unadapted response took nearly 500 ms in newborns. Neither the newborn nor the adult data can be explained by forward masking of one click on the next click. These results indicate human developmental differences in adaptation to repetitive auditory stimulation at the level of the brainstem.

  3. Unilateral and bilateral brainstem auditory-evoked response abnormalities in 900 Dalmatian dogs. (United States)

    Holliday, T A; Nelson, H J; Williams, D C; Willits, N


    In a survey of 900 Dalmatian dogs, brainstem auditory-evoked responses (BAER) and clinical observations were used to determine the incidence and sex distribution of bilateral and unilateral BAER abnormalities and their association with heterochromia iridis (HI). To assess the efficacy of BAER testing in guiding breeding programs, data from 749 dogs (subgroup A), considered to be a sample of the population at large, were compared with data from a subgroup (subgroup B; n = 151) in which selection of breeding stock had been based on BAER testing from the beginning of the 4-year survey. Brainstem auditory-evoked responses were elicited by applying click stimuli unilaterally, while applying a white noise masking sound to the contralateral ear. Under these conditions, BAER were either normal, unilaterally absent, or bilaterally absent. Dogs with bilaterally absent BAER were clinically deaf; dogs with unilaterally absent BAER were not clinically deaf but appeared dependent on their BAER-normal ears for their auditory-cued behavior. Dogs with unilaterally absent BAER often were misidentified as normal by uninformed observers. Among the 900 dogs, 648 (72.0%) were normal, 189 (21.0%) had unilateral absence of BAER, and 63 (7.0%) had bilateral absence of BAER or were clinically deaf and assumed to have bilaterally absent BAER (n = 4). Total incidence in the population sampled was assumed to be higher, because some bilaterally affected dogs that would have been members of subgroup A undoubtedly did not come to our attention. Among females, 24.0% were unilaterally abnormal and 8.2% were bilaterally abnormal whereas, among males, 17.8% were unilaterally abnormal and 5.7% were bilaterally abnormal.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Basic emotions evoked by odorants: comparison between autonomic responses and self-evaluation. (United States)

    Alaoui-Ismaïli, O; Robin, O; Rada, H; Dittmar, A; Vernet-Maury, E


    The present study was designed to analyze the relationship between self-report and physiological expression of basic emotions (happiness, surprise, fear, sadness, disgust and anger) in response to odorants. 44 subjects inhaled five odorants: vanillin, menthol, eugenol, methyl methacrylate, and propionic acid. Six autonomic nervous systems (ANS) parameters were simultaneously recorded in real time and without interference: Skin Potential (SP), Skin Resistance (SR), Skin Temperature (ST), Skin Blood Flow (SBF), Instantaneous Respiratory Frequency (IRF) and Instantaneous Heart Rate (IHR). At the end of the recording, subjects were instructed i) to identify the odorants roughly II) to situate them on an 11-point hedonic scale from highly pleasant (0) to highly unpleasant (10); and iii) to define what type of basic emotion was evoked by each odorant. In this study, the expected affects were aroused in the subjects. Vanillin and menthol were rated pleasant, while methyl methacrylate and propionic acid were judged unpleasant. Eugenol was median in hedonic estimation. ANS evaluation (each autonomic pattern induced by an odorant was transcripted into a basic emotion) shows that pleasantly connoted odorants evoked mainly happiness and surprise, but that unpleasant ones induced mainly disgust and anger. Eugenol was associated with positive and negative affects. Comparison between conscious (verbal) and unconscious (ANS) emotions, reveals that these two estimations 1) were not significantly different as far as the two pleasant odorants were concerned, 2) showed a tendency to be significantly different for eugenol odorant which was variably scored on the hedonic axis, and 3) exhibited a significant difference for the two unpleasant odorants, for which the corresponding "verbal emotion" was mainly "disgust", while the most frequent ANS emotion was "anger". In conclusion, these results show quite a good correlation between verbal and ANS estimated basic emotions. The main

  5. Common cortical responses evoked by appearance, disappearance and change of the human face

    Directory of Open Access Journals (Sweden)

    Kida Tetsuo


    Full Text Available Abstract Background To segregate luminance-related, face-related and non-specific components involved in spatio-temporal dynamics of cortical activations to a face stimulus, we recorded cortical responses to face appearance (Onset, disappearance (Offset, and change (Change using magnetoencephalography. Results Activity in and around the primary visual cortex (V1/V2 showed luminance-dependent behavior. Any of the three events evoked activity in the middle occipital gyrus (MOG at 150 ms and temporo-parietal junction (TPJ at 250 ms after the onset of each event. Onset and Change activated the fusiform gyrus (FG, while Offset did not. This FG activation showed a triphasic waveform, consistent with results of intracranial recordings in humans. Conclusion Analysis employed in this study successfully segregated four different elements involved in the spatio-temporal dynamics of cortical activations in response to a face stimulus. The results show the responses of MOG and TPJ to be associated with non-specific processes, such as the detection of abrupt changes or exogenous attention. Activity in FG corresponds to a face-specific response recorded by intracranial studies, and that in V1/V2 is related to a change in luminance.

  6. Influenza A infection attenuates relaxation responses of mouse tracheal smooth muscle evoked by acrolein. (United States)

    Cheah, Esther Y; Mann, Tracy S; Burcham, Philip C; Henry, Peter J


    The airway epithelium is an important source of relaxant mediators, and damage to the epithelium caused by respiratory tract viruses may contribute to airway hyperreactivity. The aim of this study was to determine whether influenza A-induced epithelial damage would modulate relaxation responses evoked by acrolein, a toxic and prevalent component of smoke. Male BALB/c mice were inoculated intranasally with influenza A/PR-8/34 (VIRUS-infected) or allantoic fluid (SHAM-infected). On day 4 post-inoculation, isometric tension recording studies were conducted on carbachol pre-contracted tracheal segments isolated from VIRUS and SHAM mice. Relaxant responses to acrolein (30 μM) were markedly smaller in VIRUS segments compared to SHAM segments (2 ± 1% relaxation vs. 28 ± 5%, n=14, pacrolein and SP were reduced in VIRUS segments (>35% reduction, n=6, pacrolein were profoundly diminished in tracheal segments isolated from influenza A-infected mice. The mechanism through which influenza A infection attenuates this response appears to involve reduced production of PGE2 in response to SP due to epithelial cell loss, and may provide insight into the airway hyperreactivity observed with influenza A infection.

  7. Synaptic responses evoked by tactile stimuli in Purkinje cells in mouse cerebellar cortex Crus II in vivo.

    Directory of Open Access Journals (Sweden)

    Chun-Ping Chu

    Full Text Available BACKGROUND: Sensory stimuli evoke responses in cerebellar Purkinje cells (PCs via the mossy fiber-granule cell pathway. However, the properties of synaptic responses evoked by tactile stimulation in cerebellar PCs are unknown. The present study investigated the synaptic responses of PCs in response to an air-puff stimulation on the ipsilateral whisker pad in urethane-anesthetized mice. METHODS AND MAIN RESULTS: Thirty-three PCs were recorded from 48 urethane-anesthetized adult (6-8-week-old HA/ICR mice by somatic or dendritic patch-clamp recording and pharmacological methods. Tactile stimulation to the ipsilateral whisker pad was delivered by an air-puff through a 12-gauge stainless steel tube connected with a pressurized injection system. Under current-clamp conditions (I = 0, the air-puff stimulation evoked strong inhibitory postsynaptic potentials (IPSPs in the somata of PCs. Application of SR95531, a specific GABA(A receptor antagonist, blocked IPSPs and revealed stimulation-evoked simple spike firing. Under voltage-clamp conditions, tactile stimulation evoked a sequence of transient inward currents followed by strong outward currents in the somata and dendrites in PCs. Application of SR95531 blocked outward currents and revealed excitatory postsynaptic currents (EPSCs in somata and a temporal summation of parallel fiber EPSCs in PC dendrites. We also demonstrated that PCs respond to both the onset and offset of the air-puff stimulation. CONCLUSIONS: These findings indicated that tactile stimulation induced asynchronous parallel fiber excitatory inputs onto the dendrites of PCs, and failed to evoke strong EPSCs and spike firing in PCs, but induced the rapid activation of strong GABA(A receptor-mediated inhibitory postsynaptic currents in the somata and dendrites of PCs in the cerebellar cortex Crus II in urethane-anesthetized mice.

  8. The Duration of Motor Responses Evoked with Intracortical Microstimulation in Rats Is Primarily Modulated by Stimulus Amplitude and Train Duration.

    Directory of Open Access Journals (Sweden)

    Meghan Watson

    Full Text Available Microstimulation of brain tissue plays a key role in a variety of sensory prosthetics, clinical therapies and research applications, however the effects of stimulation parameters on the responses they evoke remain widely unknown. In particular, the effects of parameters when delivered in the form of a stimulus train as opposed to a single pulse are not well understood despite the prevalence of stimulus train use. We aimed to investigate the contribution of each parameter of a stimulus train to the duration of the motor responses they evoke in forelimb muscles. We used constant-current, biphasic, square wave pulse trains in acute terminal experiments under ketamine anaesthesia. Stimulation parameters were systematically tested in a pair-wise fashion in the caudal forelimb region of the motor cortex in 7 Sprague-Dawley rats while motor evoked potential (MEP recordings from the forelimb were used to quantify the influence of each parameter in the train. Stimulus amplitude and train duration were shown to be the dominant parameters responsible for increasing the total duration of the MEP, while interphase interval had no effect. Increasing stimulus frequency from 100-200 Hz or pulse duration from 0.18-0.34 ms were also effective methods of extending response durations. Response duration was strongly correlated with peak time and amplitude. Our findings suggest that motor cortex intracortical microstimulations are often conducted at a higher frequency rate and longer train duration than necessary to evoke maximal response duration. We demonstrated that the temporal properties of the evoked response can be both predicted by certain response metrics and modulated via alterations to the stimulation signal parameters.

  9. Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. I. Normal responses (United States)

    Minor, L. B.; Lasker, D. M.; Backous, D. D.; Hullar, T. E.; Shelhamer, M. J. (Principal Investigator)


    The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in five squirrel monkeys with intact vestibular function. The VOR evoked by steps of acceleration in darkness (3,000 degrees /s(2) reaching a velocity of 150 degrees /s) began after a latency of 7.3 +/- 1.5 ms (mean +/- SD). Gain of the reflex during the acceleration was 14.2 +/- 5.2% greater than that measured once the plateau head velocity had been reached. A polynomial regression was used to analyze the trajectory of the responses to steps of acceleration. A better representation of the data was obtained from a polynomial that included a cubic term in contrast to an exclusively linear fit. For sinusoidal rotations of 0.5-15 Hz with a peak velocity of 20 degrees /s, the VOR gain measured 0.83 +/- 0.06 and did not vary across frequencies or animals. The phase of these responses was close to compensatory except at 15 Hz where a lag of 5.0 +/- 0.9 degrees was noted. The VOR gain did not vary with head velocity at 0.5 Hz but increased with velocity for rotations at frequencies of >/=4 Hz (0. 85 +/- 0.04 at 4 Hz, 20 degrees /s; 1.01 +/- 0.05 at 100 degrees /s, P < 0.0001). No responses to these rotations were noted in two animals that had undergone bilateral labyrinthectomy indicating that inertia of the eye had a negligible effect for these stimuli. We developed a mathematical model of VOR dynamics to account for these findings. The inputs to the reflex come from linear and nonlinear pathways. The linear pathway is responsible for the constant gain across frequencies at peak head velocity of 20 degrees /s and also for the phase lag at higher frequencies being less than that expected based on the reflex delay. The frequency- and velocity-dependent nonlinearity in VOR gain is accounted for by the dynamics of the nonlinear pathway. A transfer function that increases the gain of this pathway with frequency and a term related to the third power of head

  10. Calcium imaging of odor-evoked responses in the Drosophila antennal lobe. (United States)

    Silbering, Ana F; Bell, Rati; Galizia, C Giovanni; Benton, Richard


    The antennal lobe is the primary olfactory center in the insect brain and represents the anatomical and functional equivalent of the vertebrate olfactory bulb. Olfactory information in the external world is transmitted to the antennal lobe by olfactory sensory neurons (OSNs), which segregate to distinct regions of neuropil called glomeruli according to the specific olfactory receptor they express. Here, OSN axons synapse with both local interneurons (LNs), whose processes can innervate many different glomeruli, and projection neurons (PNs), which convey olfactory information to higher olfactory brain regions. Optical imaging of the activity of OSNs, LNs and PNs in the antennal lobe - traditionally using synthetic calcium indicators (e.g. calcium green, FURA-2) or voltage-sensitive dyes (e.g. RH414) - has long been an important technique to understand how olfactory stimuli are represented as spatial and temporal patterns of glomerular activity in many species of insects. Development of genetically-encoded neural activity reporters, such as the fluorescent calcium indicators G-CaMP and Cameleon, the bioluminescent calcium indicator GFP-aequorin, or a reporter of synaptic transmission, synapto-pHluorin has made the olfactory system of the fruitfly, Drosophila melanogaster, particularly accessible to neurophysiological imaging, complementing its comprehensively-described molecular, electrophysiological and neuroanatomical properties. These reporters can be selectively expressed via binary transcriptional control systems (e.g. GAL4/UAS, LexA/LexAop, Q system) in defined populations of neurons within the olfactory circuitry to dissect with high spatial and temporal resolution how odor-evoked neural activity is represented, modulated and transformed. Here we describe the preparation and analysis methods to measure odor-evoked responses in the Drosophila antennal lobe using G-CaMP. The animal preparation is minimally invasive and can be adapted to imaging using wide

  11. Habituation of auditory steady state responses evoked by amplitudemodulated acoustic signals in rats

    Directory of Open Access Journals (Sweden)

    Pavel Prado-Gutierrez


    Full Text Available Generation of the auditory steady state responses (ASSR is commonly explained by the linear combination of random background noise activity and the stationary response. Based on this model, the decrease of amplitude that occurs over the sequential averaging of epochs of the raw data has been exclusively linked to the cancelation of noise. Nevertheless, this behavior might also reflect the non-stationary response of the ASSR generators. We tested this hypothesis by characterizing the ASSR time course in rats with different auditory maturational stages. ASSR were evoked by 8-kHz tones of different supra-threshold intensities, modulated in amplitude at 115 Hz. Results show that the ASSR amplitude habituated to the sustained stimulation and that dishabituation occurred when deviant stimuli were presented. ASSR habituation increased as animals became adults, suggesting that the ability to filter acoustic stimuli with no-relevant temporal information increased with age. Results are discussed in terms of the current model of the ASSR generation and analysis procedures. They might have implications for audiometric tests designed to assess hearing in subjects who cannot provide reliable results in the psychophysical trials.

  12. Central amygdalar nucleus treated with orexin neuropeptides evoke differing feeding and grooming responses in the hamster. (United States)

    Alò, Raffaella; Avolio, Ennio; Mele, Maria; Di Vito, Anna; Canonaco, Marcello


    Interaction of the orexinergic (ORXergic) neuronal system with the excitatory (glutamate, l-Glu) or the inhibitory (GABA) neurosignaling complexes evokes major homeostatic physiological events. In this study, effects of the two ORXergic neuropeptides (ORX-A/B) on their receptor (ORX-2R) expression changes were correlated to feeding and grooming actions of the hibernating hamster (Mesocricetus auratus). Infusion of the central amygdala nucleus (CeA) with ORX-A caused hamsters to consume notable quantities of food, while ORX-B accounted for a moderate increase. Interestingly the latter neuropeptide was responsible for greater frequencies of grooming with respect to both controls and the hamsters treated with ORX-A. These distinct behavioral changes turned out to be even greater in the presence of l-Glu agonist (NMDA) while the α1 GABAA receptor agonist (zolpidem, Zol) greatly reduced ORX-A-dependent feeding bouts. Moreover, ORX-A+NMDA mainly promoted greater ORX-2R expression levels with respect to ORX-A-treated hamsters while ORX-B+Zol was instead largely responsible for a down-regulatory trend. Overall, these features point to CeA ORX-2R sites as key sensory limbic elements capable of regulating eating and grooming responses, which may provide useful insights regarding the type of molecular mechanism(s) operating during feeding bouts.

  13. Regulation by L channels of Ca(2+)-evoked secretory responses in ouabain-treated chromaffin cells. (United States)

    De Pascual, Ricardo; Colmena, Inés; Ruiz-Pascual, Lucía; Baraibar, Andrés Mateo; Egea, Javier; Gandía, Luis; García, Antonio G


    It is known that the sustained depolarisation of adrenal medullary bovine chromaffin cells (BCCs) with high K(+) concentrations produces an initial sharp catecholamine release that subsequently fades off in spite depolarisation persists. Here, we have recreated a sustained depolarisation condition of BCCs by treating them with the Na(+)/K(+) ATPase blocker ouabain; in doing so, we searched experimental conditions that permitted the development of a sustained long-term catecholamine release response that could be relevant during prolonged stress. BCCs were perifused with nominal 0Ca(2+) solution, and secretion responses were elicited by intermittent application of short 2Ca(2+) pulses (Krebs-HEPES containing 2 mM Ca(2+)). These pulses elicited a biphasic secretory pattern with an initial 30-min period with secretory responses of increasing amplitude and a second 30-min period with steady-state, non-inactivating responses. The initial phase was not due to gradual depolarisation neither to gradual increases of the cytosolic calcium transients ([Ca(2+)]c) elicited by 2Ca(2+) pulses in BBCs exposed to ouabain; both parameters increased soon after ouabain addition. Νifedipine blocked these responses, and FPL64176 potentiated them, suggesting that they were triggered by Ca(2+) entry through non-inactivating L-type calcium channels. This was corroborated by nifedipine-evoked blockade of the L-type Ca(2+) channel current and the [Ca(2+)]c transients elicited by 2Ca(2+) pulses. Furthermore, the plasmalemmal Na(+)/Ca(2+) exchanger (NCX) blocker SEA0400 caused a mild inhibition followed by a large rebound increase of the steady-state secretory responses. We conclude that these two phases of secretion are mostly contributed by Ca(2+) entry through L calcium channels, with a minor contribution of Ca(2+) entry through the reverse mode of the NCX.

  14. Middle components of the auditory evoked response in bilateral temporal lobe lesions. Report on a patient with auditory agnosia

    DEFF Research Database (Denmark)

    Parving, A; Salomon, G; Elberling, Claus


    An investigation of the middle components of the auditory evoked response (10--50 msec post-stimulus) in a patient with auditory agnosia is reported. Bilateral temporal lobe infarctions were proved by means of brain scintigraphy, CAT scanning, and regional cerebral blood flow measurements. The mi...

  15. The vestibular evoked response to linear, alternating, acceleration pulses without acoustic masking as a parameter of vestibular function

    NARCIS (Netherlands)

    Oei, MLYM; Segenhout, JM; Wit, HP; Albers, FWJ


    In this study, short latency vestibular evoked potentials (VsEPs) were recorded in five guinea pigs in response to alternating linear acceleration pulses with and without acoustic masking. A steel bolt was implanted in the skull and coupled to a shaker. Linear acceleration pulses (n = 400) in upward

  16. Quantifying attentional modulation of auditory-evoked cortical responses from single-trial electroencephalography

    Directory of Open Access Journals (Sweden)

    Inyong eChoi


    Full Text Available Selective auditory attention is essential for human listeners to be able to communicate in multi-source environments. Selective attention is known to modulate the neural representation of the auditory scene, boosting the representation of a target sound relative to the background, but the strength of this modulation, and the mechanisms contributing to it, are not well understood. Here, listeners performed a behavioral experiment demanding sustained, focused spatial auditory attention while we measured cortical responses using electroencephalography (EEG. We presented three concurrent melodic streams; listeners were asked to attend and analyze the melodic contour of one of the streams, randomly selected from trial to trial. In a control task, listeners heard the same sound mixtures, but performed the contour judgment task on a series of visual arrows, ignoring all auditory streams. We found that the cortical responses could be fit as weighted sum of event-related potentials evoked by the stimulus onsets in the competing streams. The weighting to a given stream was roughly 10 dB higher when it was attended compared to when another auditory stream was attended; during the visual task, the auditory gains were intermediate. We then used a template-matching classification scheme to classify single-trial EEG results. We found that in all subjects, we could determine which stream the subject was attending significantly better than by chance. By directly quantifying the effect of selective attention on auditory cortical responses, these results reveal that focused auditory attention both suppresses the response to an unattended stream and enhances the response to an attended stream. The single-trial classification results add to the growing body of literature suggesting that auditory attentional modulation is sufficiently robust that it could be used as a control mechanism in brain-computer interfaces.

  17. Baroreflexes of the rat. IV. ADN-evoked responses at the NTS. (United States)

    Tang, Xiaorui; Dworkin, Barry R


    In a long-term (7-21 days) neuromuscular blocked (NMB) rat preparation, using precise single-pulse aortic depressor nerve (ADN) stimulation and stable chronic evoked response (ER) recordings from the dorsal-medial solitary nucleus (dmNTS), two different response patterns were observed: continuous and discrete. For the continuous pattern, activity began approximately 3 ms after the stimulus and persisted for 45 ms; for the discrete pattern, two complexes were separated by a gap from approximately 17 to 25 ms. The early complex was probably transmitted via A-fibers: it had a low stimulus current threshold and an average conduction velocity (CV) of 0.58-5.5 m/s; the high threshold late (HTL) complex had a CV = 0.26-0.58 m/s. The average stimulus amplitude-ER magnitude transduction curves for the A and HTL complexes were sigmoidal. For individual rats, in the linear range, mean r2 = 0.96 +/- 0.03 for both complexes. The average stimulus amplitude vs. the systolic blood pressure change (delta sBP) transduction curve was also approximately linear; however, for individual rats, the relationship was not consistently reliable: mean r2 = 0.48 +/- 0.19. Approximately 90% of recording sites had respiratory, and 50% had cardiac synchronism. The NMB preparation is useful for studying central baroreflex mechanisms that operate on time scales of days or weeks, such as adaptation and other kinds of neural plasticity.

  18. Evidence-Based Filters for Signal Detection: Application to Evoked Brain Responses

    CERN Document Server

    Mubeen, M Asim


    Template-based signal detection most often relies on computing a correlation, or a dot product, between an incoming data stream and a signal template. Such a correlation results in an ongoing estimate of the magnitude of the signal in the data stream. However, it does not directly indicate the presence or absence of the signal. The problem is really one of model-testing, and the relevant quantity is the Bayesian evidence (marginal likelihood) of the signal model. Given a signal template and an ongoing data stream, we have developed an evidence-based filter that computes the Bayesian evidence that a signal is present in the data. We demonstrate this algorithm by applying it to brain-machine interface (BMI) data obtained by recording human brain electrical activity, or electroencephalography (EEG). A very popular and effective paradigm in EEG-based BMI is based on the detection of the P300 evoked brain response which is generated in response to particular sensory stimuli. The goal is to detect the presence of a...

  19. Emotional expressions evoke a differential response in the fusiform face area

    Directory of Open Access Journals (Sweden)

    Bronson Blake Harry


    Full Text Available It is widely assumed that the fusiform face area (FFA, a brain region specialised for face perception, is not involved in processing emotional expressions. This assumption is based on the proposition that the FFA is involved in face identification and only processes features that are invariant across changes due to head movements, speaking and expressing emotions. The present study tested this proposition by examining whether the response in the human FFA varies across emotional expressions with functional magnetic resonance imaging and brain decoding analysis techniques (n = 11. A one versus all classification analysis showed that most emotional expressions that participants perceived could be reliably predicted from the neural pattern of activity in left and the right FFA, suggesting that the perception of different emotional expressions recruit partially non-overlaping neural mechanisms. In addition, emotional expressions could also be decoded from the pattern of activity in the early visual cortex (EVC, indicating that retinotopic cortex also shows a differential response to emotional expressions. These results cast doubt on the idea that the FFA is involved in expression invariant face processing, and instead indicate that emotional expressions evoke partially de-correlated signals throughout occipital and posterior temporal cortex.

  20. Cognitive processing effects on auditory event-related potentials and the evoked cardiac response. (United States)

    Lawrence, Carlie A; Barry, Robert J


    The phasic evoked cardiac response (ECR) produced by innocuous stimuli requiring cognitive processing may be described as the sum of two independent response components. An initial heart rate (HR) deceleration (ECR1), and a slightly later HR acceleration (ECR2), have been hypothesised to reflect stimulus registration and cognitive processing load, respectively. This study investigated the effects of processing load in the ECR and the event-related potential, in an attempt to find similarities between measures found important in the autonomic orienting reflex context and ERP literature. We examined the effects of cognitive load within-subjects, using a long inter-stimulus interval (ISI) ANS-style paradigm. Subjects (N=40) were presented with 30-35 80dB, 1000Hz tones with a variable long ISI (7-9s), and required to silently count, or allowed to ignore, the tone in two counterbalanced stimulus blocks. The ECR showed a significant effect of counting, allowing separation of the two ECR components by subtracting the NoCount from the Count condition. The auditory ERP showed the expected obligatory processing effects in the N1, and substantial effects of cognitive load in the late positive complex (LPC). These data offer support for ANS-CNS connections worth pursuing further in future work.

  1. Neuromagnetic oscillations predict evoked-response latency delays and core language deficits in autism spectrum disorders. (United States)

    Edgar, J Christopher; Khan, Sarah Y; Blaskey, Lisa; Chow, Vivian Y; Rey, Michael; Gaetz, William; Cannon, Katelyn M; Monroe, Justin F; Cornew, Lauren; Qasmieh, Saba; Liu, Song; Welsh, John P; Levy, Susan E; Roberts, Timothy P L


    Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a 'core' abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate 'neural tone' and an inability to rapidly return to a resting state prior to the next stimulus.

  2. Middle latency auditory evoked responses in normal term infants: a longitudinal study. (United States)

    Rogers, S H; Edwards, D A; Henderson-Smart, D J; Pettigrew, A G


    Middle latency auditory evoked responses (MLAERs) were measured in 21 normal term infants, three to five days after birth and then at 6 weeks, 7 months and 1 year of age. A polyphasic waveform was elicited during natural sleep in all infants at each recording session by monaural click stimulation at a rate of 9 per second. A 70 dBHL stimulus was found to be optimal as the MLAER became less well defined when the stimulus intensity approached the threshold hearing level. The first 60 to 70 msec of the waveform was found to be most stable, with decreasing detectability of peaks at longer latencies. There was no change in wave latency or reproducibility of MLAERs recorded during different sleep states. Waves Po and Na showed a significant decrease in latency with increasing stimulus intensity at term and/or 6 weeks of age. This was not evident for the remainder of the waveform. Waves Po, Na, Pa, Nb, Pb and Nc exhibited significant decreases in latency with age, attaining values indistinguishable from adults by 7 months of age.

  3. The feeding responses evoked by endogenous cholecystokinin are regulated by different gastrointestinal sites. (United States)

    Washington, Martha C; Williams, Kasey; Sayegh, Ayman I


    The current study tested the hypothesis that cholecystokinin (CCK) A receptor (CCKAR) in areas supplied by the celiac artery (CA), stomach and upper duodenum, and the cranial mesenteric artery (CMA), small and parts of the large intestine, is necessary for reduction of meal size, prolongation of the intermeal interval (time between first and second meal) and increased satiety ratio (intermeal interval/meal size or amount of food consumed during any given unit of time) by the non-nutrient stimulator of endogenous CCK release camostat. Consistent with our previous findings camostat reduced meal size, prolonged the intermeal interval and increased the satiety ratio. Here, we report that blocking CCKAR in the area supplied by the celiac artery attenuated reduction of meal size by camostat more so than the cranial mesenteric artery route. Blocking CCKAR in the area supplied by the cranial mesenteric artery attenuated prolongation of the intermeal interval length and increased satiety ratio by camostat more so than the celiac artery route. Blocking CCKAR in the areas supplied by the femoral artery (control) failed to alter the feeding responses evoked by camostat. These results support the hypothesis that CCKAR in the area supplied by the CA is necessary for reduction of meal size by camostat whereas CCKAR in the area supplied by the CMA is necessary for prolongation of the intermeal interval and increased satiety ratio by this substance. Our results demonstrate that meal size and intermeal interval length by camostat are regulated through different gastrointestinal sites.

  4. Somatic-evoked brain responses as indicators of adaptation to nitrogen narcosis. (United States)

    Langley, T D; Hamilton, R W


    Two 2-week experimental pressure chamber exposures to nitrogen-oxygen breathing mixtures afforded an opportunity to study adaptation to nitrogen narcosis. Somatic-evoked brain responses induced by electrical stimulation of the median nerve in the wrist were processed on-line with a signal averager. The N1P2 interval was seen generally to be reduced in amplitude as a result of exposure to increased nitrogen partial pressure. Compressions with air were made from sea level and saturation to 200, 250 and 300 ft of sea water (fsw) equivalent (61, 76, and 91m). The decrement was found to be less, for equivalent exposures, in subjects who had been saturated at the pressure of 90 and 120 fsw (27 and 36 m); we interpret this as evidence of a nonspecific "adaptation." Less adaptation was seen from 30 and 60 fsw (9 and 18 m). These results are consistent with performance tests on the same exposures, and with subjective impressions. Saturation with 3 0r 4 atm of nitrogen may permit somewhat deeper diving without serious narcosis, than is possible from sea level.

  5. Differential pathlength factor informs evoked stimulus response in a mouse model of Alzheimer's disease. (United States)

    Lin, Alexander J; Ponticorvo, Adrien; Durkin, Anthony J; Venugopalan, Vasan; Choi, Bernard; Tromberg, Bruce J


    Baseline optical properties are typically assumed in calculating the differential pathlength factor (DPF) of mouse brains, a value used in the modified Beer-Lambert law to characterize an evoked stimulus response. We used spatial frequency domain imaging to measure in vivo baseline optical properties in 20-month-old control ([Formula: see text]) and triple transgenic APP/PS1/tau (3xTg-AD) ([Formula: see text]) mouse brains. Average [Formula: see text] for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text], respectively, at 460 nm; and [Formula: see text] and [Formula: see text], respectively, at 530 nm. Average [Formula: see text] for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text], respectively, at 460 nm; and [Formula: see text] and [Formula: see text], respectively, at 530 nm. The calculated DPF for control and 3xTg-AD mice was [Formula: see text] and [Formula: see text] OD mm, respectively, at 460 nm; and [Formula: see text] and [Formula: see text] OD mm, respectively, at 530 nm. In hindpaw stimulation experiments, the hemodynamic increase in brain tissue concentration of oxyhemoglobin was threefold larger and two times longer in the control mice compared to 3xTg-AD mice. Furthermore, the washout of deoxyhemoglobin from increased brain perfusion was seven times larger in controls compared to 3xTg-AD mice ([Formula: see text]).

  6. Botulinum toxin A for palmar hyperhidrosis: assessment with sympathetic skin responses evoked by train of stimuli. (United States)

    Al-Hashel, J Y; Youssry, D; Rashaed, H M; Shamov, T; Rousseff, R T


    Objective assessment of the effect of botulinum toxin A (BT) treatment in primary palmar hyperhidrosis (PH) is attempted by different methods. We decided to use for this purpose sympathetic skin responses evoked by train of stimuli (TSSR). Twenty patients with severe PH (five female, median age 24, range 18-36) were examined regularly over 3 months after receiving 50 UI BT in each palm. TSSR were recorded from the palms after sensory stimulation by a train of three supramaximal electric pulses 3 millisecond apart. Results were compared to longitudinally studied TSSR of 20 healthy sex- and age-matched control subjects. All hyperhidrosis patients reported excellent improvement. TSSR amplitudes decreased at week 1 (mean 54% range 48%-67%) and over the following months in a clinically significant trend (slope R=-.82, P<.0001). TSSR in controls changed insignificantly (±13% from the baseline). The difference between patients and controls was highly significant at any time point (P<.001). This study suggests that TSSR may help in assessment of treatments in PH. It confirms objectively the efficacy of BT in PH.

  7. Ventricular evoked response in patients with hypertrophic obstructive cardiomyopathy treated with DDD pacing

    Directory of Open Access Journals (Sweden)

    João Ricardo M. Sant'Anna


    Full Text Available OBJECTIVE: To assess the changes in ventricular evoked responses (VER produced by the decrease in left ventricular outflow tract gradient (LVOTG in patients with hypertrophic obstructive cardiomyopathy (HOCM treated with dual-chamber (DDD pacing. METHODS: A pulse generator Physios CTM (Biotronik, Germany was implanted in 9 patients with severe drug-refractory HOCM. After implantation, the following conditions were assessed: 1 Baseline evaluation: different AV delay (ranging from 150ms to 50 ms were sequentially programmed during 5 to 10 minutes, and the LVOTG (as determined by Doppler echocardiography and VER recorded; 2 standard evaluation, when the best AV delay (resulting in the lowest LVOTG programmed at the initial evaluation was maintained so that its effect on VER and LVOTG could be assessed during each chronic pacing evaluation. RESULTS: LVOTG decreased after DDD pacing, with a mean value of 59 ± 24 mmHg after dual chamber pacemaker, which was significantly less than the gradient before pacing (98 + 22mmHg. An AV delay >100ms produced a significantly lower decrease in VER depolarization duration (VER DD when compared to an AV delay <=100ms. Linear regression analyses showed a significant correlation between the LVOTG values and the magnitude of VER (r=0.69; p<0.05 in the 9 studied patients. CONCLUSION: The telemetry obtained intramyocardial electrogram is a sensitive means to assess left ventricular dynamics in patients with HOCM treated with DDD pacing.

  8. Conditioning stimulation techniques for enhancement of transcranially elicited evoked motor responses

    NARCIS (Netherlands)

    Journee, H. -L.; Polak, H. E.; De Kleuver, M.


    Introduction. - In spite of the use of multipulse, transcranial electrical stimulation (TES) is still insufficient in a subgroup of patients to elicit motor-evoked potentials during intraoperative neurophysiological monitoring (IONM). Classic facilitation methods used in awake patients are precluded

  9. Activation of histamine H3 receptors produces presynaptic inhibition of neurally evoked cat nictitating membrane responses in vivo. (United States)

    Koss, M C; Hey, J A


    This study was undertaken in order to determine the potential role of prejunctional histamine H3 receptors in an in vivo adrenergic model system. Frequency-dependent nictitating membrane responses were elicited by sympathetic nerve stimulation in anesthetized cats. Systemic administration of the selective histamine H3 receptor agonist, (R)-alpha-methylhistamine (R alpha MeHA) produced a dose-related depression of amplitude of the evoked nictitating membrane responses with a threshold of about 10 micrograms/kg and maximal effect (50% depression at the lowest frequency; 0.5 Hz) seen at 100-300 micrograms/kg. Responses obtained with low frequency stimulation were more sensitive to depression by R alpha MeHA than were responses evoked with higher frequencies of stimulation. Larger doses of R alpha MeHA given to the same animals, failed to produce additional inhibition. R alpha MeHA depressed the amplitude of nictitating membrane responses evoked by either pre- or postganglionic nerve stimulation to an equivalent degree. This depressant action of R alpha MeHA was antagonized by pretreatment with the specific histamine H3 antagonist, thioperamide (3 mg/kg), but not by combined pretreatment with histamine H1 and H2 blockers chlorpheniramine (300 micrograms/kg) and cimetidine (5 mg/kg). Intravenous administration of adrenaline (1-30 micrograms/kg) also produced graded nictitating membrane responses that were not altered by subsequent administration of R alpha MeHA. These results suggest that histamine H3 receptors are involved in the modulation of neurally evoked noradrenaline release in the cat nictitating membrane by an inhibitory presynaptic action.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. In situ fluorescence imaging of glutamate-evoked mitochondrial Na+ responses in astrocytes. (United States)

    Bernardinelli, Yann; Azarias, Guillaume; Chatton, Jean-Yves


    Astrocytes can experience large intracellular Na+ changes following the activation of the Na+-coupled glutamate transport. The present study investigated whether cytosolic Na+ changes are transmitted to mitochondria, which could therefore influence their function and contribute to the overall intracellular Na+ regulation. Mitochondrial Na+ (Na+(mit)) changes were monitored using the Na+-sensitive fluorescent probe CoroNa Red (CR) in intact primary cortical astrocytes, as opposed to the classical isolated mitochondria preparation. The mitochondrial localization and Na+ sensitivity of the dye were first verified and indicated that it can be safely used as a selective Na+(mit) indicator. We found by simultaneously monitoring cytosolic and mitochondrial Na+ using sodium-binding benzofuran isophthalate and CR, respectively, that glutamate-evoked cytosolic Na+ elevations are transmitted to mitochondria. The resting Na+(mit) concentration was estimated at 19.0 +/- 0.8 mM, reaching 30.1 +/- 1.2 mM during 200 microM glutamate application. Blockers of conductances potentially mediating Na+ entry (calcium uniporter, monovalent cation conductances, K+(ATP) channels) were not able to prevent the Na+(mit) response to glutamate. However, Ca2+ and its exchange with Na+ appear to play an important role in mediating mitochondrial Na+ entry as chelating intracellular Ca2+ with BAPTA or inhibiting Na+/Ca2+ exchanger with CGP-37157 diminished the Na+(mit) response. Moreover, intracellular Ca2+ increase achieved by photoactivation of caged Ca2+ also induced a Na+(mit) elevation. Inhibition of mitochondrial Na/H antiporter using ethylisopropyl-amiloride caused a steady increase in Na+(mit) without increasing cytosolic Na+, indicating that Na+ extrusion from mitochondria is mediated by these exchangers. Thus, mitochondria in intact astrocytes are equipped to efficiently sense cellular Na+ signals and to dynamically regulate their Na+ content.

  11. Modulation of auditory evoked responses to spectral and temporal changes by behavioral discrimination training

    Directory of Open Access Journals (Sweden)

    Okamoto Hidehiko


    Full Text Available Abstract Background Due to auditory experience, musicians have better auditory expertise than non-musicians. An increased neocortical activity during auditory oddball stimulation was observed in different studies for musicians and for non-musicians after discrimination training. This suggests a modification of synaptic strength among simultaneously active neurons due to the training. We used amplitude-modulated tones (AM presented in an oddball sequence and manipulated their carrier or modulation frequencies. We investigated non-musicians in order to see if behavioral discrimination training could modify the neocortical activity generated by change detection of AM tone attributes (carrier or modulation frequency. Cortical evoked responses like N1 and mismatch negativity (MMN triggered by sound changes were recorded by a whole head magnetoencephalographic system (MEG. We investigated (i how the auditory cortex reacts to pitch difference (in carrier frequency and changes in temporal features (modulation frequency of AM tones and (ii how discrimination training modulates the neuronal activity reflecting the transient auditory responses generated in the auditory cortex. Results The results showed that, additionally to an improvement of the behavioral discrimination performance, discrimination training of carrier frequency changes significantly modulates the MMN and N1 response amplitudes after the training. This process was accompanied by an attention switch to the deviant stimulus after the training procedure identified by the occurrence of a P3a component. In contrast, the training in discrimination of modulation frequency was not sufficient to improve the behavioral discrimination performance and to alternate the cortical response (MMN to the modulation frequency change. The N1 amplitude, however, showed significant increase after and one week after the training. Similar to the training in carrier frequency discrimination, a long lasting

  12. The Role of Immittance Audiometry in Detecting Middle Ear Disease


    Jacobson, John T.


    Immittance audiometry is an objective technique which evaluates middle ear function by three procedures: static immittance, tympanometry, and the measurement of acoustic reflex threshold sensitivity. This article discusses the technique's ability to identify middle ear effusion, the single leading ear disease in children.

  13. Visual reinforcement audiometry: an Adobe Flash based approach. (United States)

    Atherton, Steve


    Visual Reinforcement Audiometry (VRA) is a key behavioural test for young children. It is central to the diagnosis of hearing-impaired infants (1) . Habituation to the visual reinforcement can give misleading results. Medical Illustration ABM University Health Board has designed a collection of Flash animations to overcome this.

  14. Proprioceptive evoked potentials in man: cerebral responses to changing weight loads on the hand

    DEFF Research Database (Denmark)

    Arnfred, S; He, Chen; Eder, D


    We studied cerebral evoked potentials on the scalp to the stimulation of the right hand from a change in weight of 400-480 g in ten subjects. Rise-time was 20g/10 ms, Inter Stimulus Interval 2s and stimulus duration was 100 ms. The cerebral activations were a double positive contralateral C3'/P70......, P190, and a single negative frontal Fz/N70 component. We conclude that a brisk change of a hand held load elicits a significant evoked potential (EP) unlike the electrical somato-sensory EP (SEP). The stimulus is perceived as applied force. For this reason we call it a proprioceptive EP (PEP...

  15. A low cost setup for behavioral audiometry in rodents. (United States)

    Tziridis, Konstantin; Ahlf, Sönke; Schulze, Holger


    In auditory animal research it is crucial to have precise information about basic hearing parameters of the animal subjects that are involved in the experiments. Such parameters may be physiological response characteristics of the auditory pathway, e.g. via brainstem audiometry (BERA). But these methods allow only indirect and uncertain extrapolations about the auditory percept that corresponds to these physiological parameters. To assess the perceptual level of hearing, behavioral methods have to be used. A potential problem with the use of behavioral methods for the description of perception in animal models is the fact that most of these methods involve some kind of learning paradigm before the subjects can be behaviorally tested, e.g. animals may have to learn to press a lever in response to a sound. As these learning paradigms change perception itself (1,2) they consequently will influence any result about perception obtained with these methods and therefore have to be interpreted with caution. Exceptions are paradigms that make use of reflex responses, because here no learning paradigms have to be carried out prior to perceptual testing. One such reflex response is the acoustic startle response (ASR) that can highly reproducibly be elicited with unexpected loud sounds in naïve animals. This ASR in turn can be influenced by preceding sounds depending on the perceptibility of this preceding stimulus: Sounds well above hearing threshold will completely inhibit the amplitude of the ASR; sounds close to threshold will only slightly inhibit the ASR. This phenomenon is called pre-pulse inhibition (PPI) (3,4), and the amount of PPI on the ASR gradually depends on the perceptibility of the pre-pulse. PPI of the ASR is therefore well suited to determine behavioral audiograms in naïve, non-trained animals, to determine hearing impairments or even to detect possible subjective tinnitus percepts in these animals. In this paper we demonstrate the use of this method in a

  16. Normalization of Pain-Evoked Neural Responses Using Spontaneous EEG Improves the Performance of EEG-Based Cross-Individual Pain Prediction (United States)

    Bai, Yanru; Huang, Gan; Tu, Yiheng; Tan, Ao; Hung, Yeung Sam; Zhang, Zhiguo


    An effective physiological pain assessment method that complements the gold standard of self-report is highly desired in pain clinical research and practice. Recent studies have shown that pain-evoked electroencephalography (EEG) responses could be used as a readout of perceived pain intensity. Existing EEG-based pain assessment is normally achieved by cross-individual prediction (i.e., to train a prediction model from a group of individuals and to apply the model on a new individual), so its performance is seriously hampered by the substantial inter-individual variability in pain-evoked EEG responses. In this study, to reduce the inter-individual variability in pain-evoked EEG and to improve the accuracy of cross-individual pain prediction, we examined the relationship between pain-evoked EEG, spontaneous EEG, and pain perception on a pain EEG dataset, where a large number of laser pulses (>100) with a wide energy range were delivered. Motivated by our finding that an individual's pain-evoked EEG responses is significantly correlated with his/her spontaneous EEG in terms of magnitude, we proposed a normalization method for pain-evoked EEG responses using one's spontaneous EEG to reduce the inter-individual variability. In addition, a nonlinear relationship between the level of pain perception and pain-evoked EEG responses was obtained, which inspired us to further develop a new two-stage pain prediction strategy, a binary classification of low-pain and high-pain trials followed by a continuous prediction for high-pain trials only, both of which used spontaneous-EEG-normalized magnitudes of evoked EEG responses as features. Results show that the proposed normalization strategy can effectively reduce the inter-individual variability in pain-evoked responses, and the two-stage pain prediction method can lead to a higher prediction accuracy. PMID:27148028

  17. Evaluation of auditory brain-stem evoked response in middle: Aged type 2 diabetes mellitus with normal hearing subjects

    Directory of Open Access Journals (Sweden)

    Debadatta Mahallik


    Full Text Available Background: Diabetes mellitus (DM is commonly metabolic disorders of carbohydrate in which blood glucose levels are abnormally high due to relative or absolute insulin deficiency. In addition, it is characterized by abnormal metabolism of fat, protein resulting from insulin deficit or insulin action, or both. There are two broad categories of DM are designated as type 1 and type 2. Type 2 diabetes is due to predominantly insulin resistance with relative insulin deficiency noninsulin-dependent DM. Type 2 diabetes is much more common than insulin-dependent DM. Objectives: The aim of this study was to assess, if there is any abnormality in neural conduction in auditory brain-stem pathway in type 2 DM patients having normal hearing sensitivity when compared to age-matched healthy populations. Materials and Methods: This study included middle - aged 25 subjects having normal hearing with diabetes type 2 mellitus. All were submitted to the full audiological history taking, otological examination, basic audiological evaluation and auditory brain-stem response audiometry which was recorded in both ears, followed by calculation of the absolute latencies of wave I, III and V, as well as interpeak latencies I-III, III-V, I-V. Results: Type 2 DM patients showed significant prolonged absolute latencies of I, III (P = 0.001 and interpeak latencies I-III, III-V and I-V in left ear (P = 0.001 and absolute latencies of I, V (P = 0.001, interpeak latencies III-V was statistically significant in right ear. Conclusions: The prolonged absolute latencies and interpeak latencies suggests abnormal neural firing synchronization or in the transmission in the auditory pathways in normal hearing type 2 diabetes mellitus patients.

  18. Eugenol and carvacrol excite first- and second-order trigeminal neurons and enhance their heat-evoked responses. (United States)

    Klein, A H; Joe, C L; Davoodi, A; Takechi, K; Carstens, M I; Carstens, E


    Eugenol and carvacrol from clove and oregano, respectively, are agonists of the warmth-sensitive transient receptor potential channel TRPV3 and the irritant-sensitive transient receptor potential ankyrin (TRPA)-1. Eugenol and carvacrol induce oral irritation that rapidly desensitizes, accompanied by brief enhancement of innocuous warmth and heat pain in humans. We presently investigated if eugenol and carvacrol activate nociceptive primary afferent and higher order trigeminal neurons and enhance their heat-evoked responses, using calcium imaging of cultured trigeminal ganglion (TG) and dorsal root ganglion (DRG) neurons, and in vivo single-unit recordings in trigeminal subnucleus caudalis (Vc) of rats. Eugenol and carvacrol activated 20-30% of TG and 7-20% of DRG cells, the majority of which additionally responded to menthol, mustard oil and/or capsaicin. TG cell responses to innocuous (39°) and noxious (42 °C) heating were enhanced by eugenol and carvacrol. We identified dorsomedial Vc neurons responsive to noxious heating of the tongue in pentobarbital-anesthetized rats. Eugenol and carvacrol dose-dependently elicited desensitizing responses in 55% and 73% of heat-sensitive units, respectively. Responses to noxious heat were briefly enhanced by eugenol and carvacrol. Many eugenol- and carvacrol-responsive units also responded to menthol, cinnamaldehyde and capsaicin. These data support a peripheral site for eugenol and carvacrol to enhance warmth- and noxious heat-evoked responses of trigeminal neurons, and are consistent with the observation that these agonists briefly enhance warmth and heat pain on the human tongue.

  19. Facial motor responses evoked by direct electrical stimulation of the trigeminal root. Localizing value for radiofrequency thermorhizotomy. (United States)

    Sindou, M; Fobe, J L; Berthier, E; Vial, C


    In Sweet's description of RF-thermocoagulation for trigeminal neuralgia, the trigeminal nerve was stimulated at 50 c/s to evoke paraesthesias, in order to check the electrode location before the thermolesion is made. In 1979, we changed the frequency to 5 c/s, so as to produce in addition twitches in the masticatory muscles (in stead of the less detectable tetanization produced by 50 c/s stimulation). Since then, we started to observe, also, twitches in the muscles innervated by the facial nerve. These twitches were not always in the Orbicularis oculi (which corresponds to the classical blink reflex), but also in the lower facial muscles. Such clinically observable evoked motor responses (EMR)-which had not been reported before--were noticed in 44% of the 459 procedures performed from 1979 to 1988. When EMR were present, the threshold to evoke paraesthesias before thermolesion, and the duration of the thermolesion for obtaining a marked hypoaesthesia covering the entire painful territory, were significantly lower, respectively p trigemino-facial reflex. A preliminary intra-operative EMG study clearly shows that for EMR in the upper part of the face we are dealing with blink-like reflexes, whilst for EMR in the lower face, mechanisms still remain unclear and need further study to be understood.

  20. Effects of broadband noise on cortical evoked auditory responses at different loudness levels in young adults. (United States)

    Sharma, Mridula; Purdy, Suzanne C; Munro, Kevin J; Sawaya, Kathleen; Peter, Varghese


    Young adults with no history of hearing concerns were tested to investigate their /da/-evoked cortical auditory evoked potentials (P1-N1-P2) recorded from 32 scalp electrodes in the presence and absence of noise at three different loudness levels (soft, comfortable, and loud), at a fixed signal-to-noise ratio (+3 dB). P1 peak latency significantly increased at soft and loud levels, and N1 and P2 latencies increased at all three levels in the presence of noise, compared with the quiet condition. P1 amplitude was significantly larger in quiet than in noise conditions at the loudest level. N1 amplitude was larger in quiet than in noise for the soft level only. P2 amplitude was reduced in the presence of noise to a similar degree at all loudness levels. The differential effects of noise on P1, N1, and P2 suggest differences in auditory processes underlying these peaks. The combination of level and signal-to-noise ratio should be considered when using cortical auditory evoked potentials as an electrophysiological indicator of degraded speech processing.

  1. Activation of NTS A(1) adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex. (United States)

    Ichinose, Tomoko K; Minic, Zeljka; Li, Cailian; O'Leary, Donal S; Scislo, Tadeusz J


    Previously we have shown that adenosine operating via the A(1) receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it is likely that adenosine operating via A(1) receptors in the NTS may differentially inhibit regional sympathetic responses evoked by activation of cardiopulmonary chemoreceptors. Therefore, in urethane-chloralose-anesthetized rats (n = 37) we compared regional sympathoinhibition evoked by the cardiopulmonary chemoreflex (activated with right atrial injections of serotonin 5HT(3) receptor agonist phenylbiguanide, PBG, 1-8 μg/kg) before and after selective stimulation of NTS A(1) adenosine receptors [microinjections of N(6)-cyclopentyl adenosine (CPA), 0.033-330 pmol/50 nl]. Activation of cardiopulmonary chemoreceptors evoked differential, dose-dependent sympathoinhibition (RSNA>ASNA>LSNA), and decreases in arterial pressure and heart rate. These differential sympathetic responses were uniformly attenuated in dose-dependent manner by microinjections of CPA into the NTS. Volume control (n = 11) and blockade of adenosine receptor subtypes in the NTS via 8-(p-sulfophenyl)theophylline (8-SPT, 1 nmol in 100 nl) (n = 9) did not affect the reflex responses. We conclude that activation of NTS A(1) adenosine receptors uniformly inhibits neural and cardiovascular cardiopulmonary chemoreflex responses. A(1) adenosine receptors have no tonic modulatory effect on this reflex under normal conditions. However, when adenosine is released into the NTS (i.e., during stress or severe hypotension/ischemia), it may serve as negative feedback regulator for depressor and sympathoinhibitory reflexes

  2. [Dissociation of visual evoked responses to hemi-field or full-field flash-checkerboard stimulation]. (United States)

    Samson-Dollfus, D; Layet, A; Hannequin, D; Menard, J F; Parain, D; Nehili, F


    Unexpected visual evoked responses (VERs) were recorded in 5 subjects with tumoral, ischemic or hemorrhagic lesions of the retrochiasmatic visual pathways. The flash pattern stimulation was always binocular and involved full-field and half-field stimuli. In these 5 cases, the total field VER was asymmetrical with anomalies on the affected occipital region. However half-field VERs P100 contralateral to the stimulus were noted both on the normal and on the affected occipital region. One can ask if this is not an electrophysiological equivalent of the clinical relative hemianopsia.

  3. Effect of tolperisone on the resting brain and on evoked responses, an phMRI BOLD study. (United States)

    Kocsis, Pál; Gajári, Dávid; Deli, Levente; Gőcze, Krisztina Zsedrovitsné; Pozsgay, Zsófia; Tihanyi, Károly


    Tolperisone is a voltage gated sodium channel blocker, centrally acting muscle relaxant drug, with a very advantageous side effect profile. Like other sodium channel blockers, it has weak affinity to the resting state and high affinity to the open/inactivated state of the channel. In this paper, its effect on BOLD responses in rat brain were elucidated both on the resting brain and paw stimulation evoked BOLD responses. Tolperisone did not exert any visible effect on resting brain, but strongly inhibited the paw stimulation evoked BOLD responses, showing somewhat higher efficacy in brain areas involved in pain sensation. This finding is in a good agreement with its sodium channel blocking profile. In the resting brain, most of the channels are in resting state. Electric train stimuli of the paw results in over activated neurons, where most sodium channels are in open or inactivated state. These data suggest that the very advantageous profile of tolperisone can be explained by its selective action on open or inactivated sodium channels of over-activated neurons in various brain regions rather than by a selective effect in the spinal cord as suggested previously.

  4. Extended high-frequency audiometry (9,000-20,000 Hz). Usefulness in audiological diagnosis. (United States)

    Rodríguez Valiente, Antonio; Roldán Fidalgo, Amaya; Villarreal, Ithzel M; García Berrocal, José R


    Early detection and appropriate treatment of hearing loss are essential to minimise the consequences of hearing loss. In addition to conventional audiometry (125-8,000 Hz), extended high-frequency audiometry (9,000-20,000 Hz) is available. This type of audiometry may be useful in early diagnosis of hearing loss in certain conditions, such as the ototoxic effect of cisplatin-based treatment, noise exposure or oral misunderstanding, especially in noisy environments. Eleven examples are shown in which extended high-frequency audiometry has been useful in early detection of hearing loss, despite the subject having a normal conventional audiometry. The goal of the present paper was to highlight the importance of the extended high-frequency audiometry examination for it to become a standard tool in routine audiological examinations.

  5. The relation of ongoing brain activity, evoked neural responses, and cognition

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    Sepideh Sadaghiani


    Full Text Available Ongoing brain activity has been observed since the earliest neurophysiological recordings and is found over a wide range of temporal and spatial scales. It is characterized by remarkably large spontaneous modulations. Here, we review evidence for the functional role of these ongoing activity fluctuations and argue that they constitute an essential property of the neural architecture underlying cognition. The role of spontaneous activity fluctuations is probably best understood when considering both their spatiotemporal structure and their functional impact on cognition. We first briefly argue against a ‘segregationist’ view on ongoing activity, both in time and space, countering this view with an emphasis on integration within a hierarchical spatiotemporal organization of intrinsic activity. We then highlight the flexibility and context-sensitivity of intrinsic functional connectivity that suggest its involvement in functionally relevant information processing. This role in information processing is pursued by reviewing how ongoing brain activity interacts with afferent and efferent information exchange of the brain with its environment. We focus on the relationship between the variability of ongoing and evoked brain activity, and review recent reports that tie ongoing brain activity fluctuations to variability in human perception and behavior. Finally, these observations are discussed within the framework of the free-energy principle which – applied to human brain function - provides a theoretical account for a non-random, coordinated interaction of ongoing and evoked activity in perception and behaviour.

  6. Valproate-induced reversible sensorineural hearing loss: a case report with serial audiometry and pharmacokinetic modelling during a valproate rechallenge. (United States)

    Yeap, Li-Ling; Lim, Kheng-Seang; Lo, Yoke-Lin; Bakar, Mohd Zukiflee Abu; Tan, Chong-Tin


    Hearing loss has been reported with valproic acid (VPA) use. However, this is the first case of VPA-induced hearing loss that was tested and confirmed with a VPA rechallenge, supported by serial audiometry and pharmacokinetic modelling. A 39-year-old truck driver with temporal lobe epilepsy was treated with VPA at 400 mg, twice daily, and developed hearing loss after each dose, but recovered within three hours. Hearing loss fully resolved after VPA discontinuation. Audiometry performed five hours after VPA rechallenge showed significant improvement in hearing thresholds. Pharmacokinetic modelling during the VPA rechallenge showed that hearing loss occurred at a level below the therapeutic range. Brainstem auditory evoked potential at three months after VPA discontinuation showed bilateral conduction defect between the cochlear and superior olivary nucleus, supporting a pre-existing auditory deficit. VPA may cause temporary hearing threshold shift. Pre-existing auditory defect may be a risk factor for VPA-induced hearing loss. Caution should be taken while prescribing VPA to patients with pre-existing auditory deficit.

  7. High-frequency audiometry: A means for early diagnosis of noise-induced hearing loss


    Amir H Mehrparvar; Seyyed J Mirmohammadi; Abbas Ghoreyshi; Abolfazl Mollasadeghi; Ziba Loukzadeh


    Noise-induced hearing loss (NIHL), an irreversible disorder, is a common problem in industrial settings. Early diagnosis of NIHL can help prevent the progression of hearing loss, especially in speech frequencies. For early diagnosis of NIHL, audiometry is performed routinely in conventional frequencies. We designed this study to compare the effect of noise on high-frequency audiometry (HFA) and conventional audiometry. In a historical cohort study, we compared hearing threshold and prevalence...

  8. Task-specific modulation of human auditory evoked responses in a delayed-match-to-sample task

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    Feng eRong


    Full Text Available In this study, we focus our investigation on task-specific cognitive modulation of early cortical auditory processing in human cerebral cortex. During the experiments, we acquired whole-head magnetoencephalography (MEG data while participants were performing an auditory delayed-match-to-sample (DMS task and associated control tasks. Using a spatial filtering beamformer technique to simultaneously estimate multiple source activities inside the human brain, we observed a significant DMS-specific suppression of the auditory evoked response to the second stimulus in a sound pair, with the center of the effect being located in the vicinity of the left auditory cortex. For the right auditory cortex, a non-invariant suppression effect was observed in both DMS and control tasks. Furthermore, analysis of coherence revealed a beta band (12 ~ 20 Hz DMS-specific enhanced functional interaction between the sources in left auditory cortex and those in left inferior frontal gyrus, which has been shown to involve in short-term memory processing during the delay period of DMS task. Our findings support the view that early evoked cortical responses to incoming acoustic stimuli can be modulated by task-specific cognitive functions by means of frontal-temporal functional interactions.

  9. Relationship between the findings of pure-tone audiometry and otoacoustic emission tests on military police personnel

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    Guida, Heraldo Lorena


    Full Text Available Introduction: Otoacoustic emissions can be an alternative for cochlear evaluation in noise induced hearing loss (NIHL. Objective: To investigate the correlation between the findings of audiometry results and distortion product otoacoustic emissions (DPOAE in the military police. Method: from cross-sectional and retrospective study, 200 military police officers were submitted to audiological evaluation - pure tone audiometry and DPOAE. Results: considering the provisions of Ordinance 19 of the Labour Department, the results were suggestive of induced hearing loss by high sound pressure levels in 58 individuals, distributed as follows: 28 (48.3% bilateral cases and 30 (51.7% unilateral cases, and 15 (25.85% in each ear. The correlation between the audiometric and DPOAE showed statistical significance in most of the frequencies tested in both ears, confirming that the greater the degree of hearing loss, the smaller the DPOAE amplitudes. In addition, there was observed significant difference between the DPOAEs amplitudes of normal subjects and listeners with hearing loss, confirming the lowering of responses in the group with hearing loss. Conclusion: considering that the correlation between pure tone audiometry and DPOAE, we conclude that otoacoustic emissions can be a complementary tool for the detection and control of NIHL in military police.

  10. Prematurely delivered rats show improved motor coordination during sensory-evoked motor responses compared to age-matched controls. (United States)

    Roberto, Megan E; Brumley, Michele R


    The amount of postnatal experience for perinatal rats was manipulated by delivering pups one day early (postconception day 21; PC21) by cesarean delivery and comparing their motor behavior to age-matched controls on PC22 (the typical day of birth). On PC22, pups were tested on multiple measures of motor coordination: leg extension response (LER), facial wiping, contact righting, and fore- and hindlimb stepping. The LER and facial wiping provided measures of synchronous hind- and forelimb coordination, respectively, and were sensory-evoked. Contact righting also was sensory-evoked and provided a measure of axial coordination. Stepping provided a measure of alternated forelimb and hindlimb coordination and was induced with the serotonin receptor agonist quipazine. Pups that were delivered prematurely and spent an additional day in the postnatal environment showed more bilateral limb coordination during expression of the LER and facial wiping, as well as a more mature righting strategy, compared to controls. These findings suggest that experience around the time of birth shapes motor coordination and the expression of species-typical behavior in the developing rat.

  11. Visual Evoked Potential Response Among Drug Abusers- A Cross Sectional Study (United States)

    Sharma, Rajeev; Thapar, Satish; Mittal, Shilekh


    Introduction There is important preclinical evidence that substance abuse may produce neurophysiological disturbances particularly in relation to altered neural synchronization in Visual Evoked Potentials (VEP). Aim The purpose of current study was to compare the latencies and amplitudes of different waveforms of VEP among different drug abusers and controls and also to identify early neurological damage so that proper counseling and timely intervention can be undertaken. Materials and Methods VEP was assessed by Data Acquisition and Analysis system in a sample of 58 drug abusers, all males, within age group of 15-45 years as well as in age matched 30 healthy controls. The peak latencies and peak to peak amplitudes of different waveforms were measured by applying one-way Anova test and unpaired t-test using SPSS version 16. Results In between drug abusers and controls, the difference in the duration of N75 and P100 waveform of VEP was found to be statistically highly significant (pdrug abusers in both eyes. Conclusion Chronic intoxication by different drugs has been extensively associated with amplitude reduction of P100 and prolonged latency of N75 and P100 reflecting an adverse effects of drug dependence on neural transmission within primary visual areas of brain. PMID:27042456

  12. Effects of OnabotulintoxinA on Habituation of Laser Evoked Responses in Chronic Migraine

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    Marina de Tommaso


    Full Text Available Onabotulintoxin A (BontA is an efficacious preventive treatment for chronic migraine, though the specific mechanism of action is still under discussion. The study aims: (1 To evaluate pain processing modifications in chronic migraine patients (CM under single BontA administration in pericranial muscles, by means of CO2 Laser Evoked Potentials (LEPs obtained by the stimulation of the skin over the right frontal and trapezius injection sites and hand dorsum, in a double blind placebo controlled crossover design. (2 To correlate main LEPs findings with clinical outcome after one year of BontA treatment. Twenty refractory CM patients were included in the analysis. The LEPs were recorded in basal conditions and seven days after BontA (PREEMPT protocol and saline solution injection. The N1, N2 and P2 amplitude and latencies and N2P2 habituation index were evaluated and correlated with the percent change of headache frequency after one year of toxin treatment. After seven days of BontA treatment, a normalization of the trigeminal habituation index was observed, which was correlated with the clinical outcome after one year of BontA therapy. Patients displaying trigeminal LEPs facilitation at T0 time showed a more efficient therapeutic outcome. Neurotoxin may exert a modulating effect on trigeminal nociception, normalizing central neurotransmission.

  13. Neuropathological differences between areas B17 and B18: implications for visual evoked responses in Alzheimer's disease. (United States)

    Armstrong, R A


    The density of senile plaques (SP) and neurofibrillary tangles (NFT) was estimated at post-mortem in areas B17 and B18 of the visual cortex in 18 Alzheimer's disease (AD) cases which varied in disease onset and duration. The density of SP in B17 and NFT in B17 and B18 declined significantly with age at death of the patient. The density of SP and NFT was greater in B18 than B17 but only in cases of earlier onset and shorter duration. The pathological differences between B17 and B18 could explain the visual evoked responses (VER) that have been reported in AD. However, the differences were small, and changes in the afferent pathways remain the most likely explanation for the VER in AD.

  14. Comparison of the developmental changes of the brainstem auditory evoked response (BAER) in taurine-supplemented and taurine-deficient kittens. (United States)

    Vallecalle-Sandoval, M H; Heaney, G; Sersen, E; Sturman, J A


    A similar development of the brainstem auditory evoked response is present in taurine-supplemented and taurine-deficient kittens between the second postnatal week and the third month of life. Between birth and the second postnatal week kittens from mothers fed the 1% taurine diet showed earlier maturation of the brainstem auditory evoked response as indicated by lower threshold, shorter P1 latency and shorter central conduction time when compared to the kittens from mothers fed the 0.05% taurine diet. These results suggest an important role of taurine in the anatomical and functional development of the auditory system.

  15. High-frequency audiometry: a means for early diagnosis of noise-induced hearing loss. (United States)

    Mehrparvar, Amir H; Mirmohammadi, Seyyed J; Ghoreyshi, Abbas; Mollasadeghi, Abolfazl; Loukzadeh, Ziba


    Noise-induced hearing loss (NIHL), an irreversible disorder, is a common problem in industrial settings. Early diagnosis of NIHL can help prevent the progression of hearing loss, especially in speech frequencies. For early diagnosis of NIHL, audiometry is performed routinely in conventional frequencies. We designed this study to compare the effect of noise on high-frequency audiometry (HFA) and conventional audiometry. In a historical cohort study, we compared hearing threshold and prevalence of hearing loss in conventional and high frequencies of audiometry among textile workers divided into two groups: With and without exposure to noise more than 85 dB. The highest hearing threshold was observed at 4000 Hz, 6000 Hz and 16000 Hz in conventional right ear audiometry, conventional left ear audiometry and HFA in each ear, respectively. The hearing threshold was significantly higher at 16000 Hz compared to 4000. Hearing loss was more common in HFA than conventional audiometry. HFA is more sensitive to detect NIHL than conventional audiometry. It can be useful for early diagnosis of hearing sensitivity to noise, and thus preventing hearing loss in lower frequencies especially speech frequencies.

  16. Contrast sensitivity test and conventional and high frequency audiometry: information beyond that required to prescribe lenses and headsets (United States)

    Comastri, S. A.; Martin, G.; Simon, J. M.; Angarano, C.; Dominguez, S.; Luzzi, F.; Lanusse, M.; Ranieri, M. V.; Boccio, C. M.


    In Optometry and in Audiology, the routine tests to prescribe correction lenses and headsets are respectively the visual acuity test (the first chart with letters was developed by Snellen in 1862) and conventional pure tone audiometry (the first audiometer with electrical current was devised by Hartmann in 1878). At present there are psychophysical non invasive tests that, besides evaluating visual and auditory performance globally and even in cases catalogued as normal according to routine tests, supply early information regarding diseases such as diabetes, hypertension, renal failure, cardiovascular problems, etc. Concerning Optometry, one of these tests is the achromatic luminance contrast sensitivity test (introduced by Schade in 1956). Concerning Audiology, one of these tests is high frequency pure tone audiometry (introduced a few decades ago) which yields information relative to pathologies affecting the basal cochlea and complements data resulting from conventional audiometry. These utilities of the contrast sensitivity test and of pure tone audiometry derive from the facts that Fourier components constitute the basis to synthesize stimuli present at the entrance of the visual and auditory systems; that these systems responses depend on frequencies and that the patient's psychophysical state affects frequency processing. The frequency of interest in the former test is the effective spatial frequency (inverse of the angle subtended at the eye by a cycle of a sinusoidal grating and measured in cycles/degree) and, in the latter, the temporal frequency (measured in cycles/sec). Both tests have similar duration and consist in determining the patient's threshold (corresponding to the inverse multiplicative of the contrast or to the inverse additive of the sound intensity level) for each harmonic stimulus present at the system entrance (sinusoidal grating or pure tone sound). In this article the frequencies, standard normality curves and abnormal threshold shifts

  17. Somatosensory evoked field in response to visuotactile stimulation in 3- to 4-year-old children

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    Gerard Bastiaan Remijn


    Full Text Available A child-customsized magnetoencephalography (MEG system was used to investigate somatosensory evoked field (SEF in 3- to 4-year-old children. Three stimulus conditions were used in which the children received tactile-only stimulation to their left index finger, or visuotactile stimulation. In the two visuotactile conditions the children received tactile stimulation to their finger while they watched a video of tactile stimulation applied either to someone else’s finger (the finger-touch condition, or to someone else’s toe (the toe-touch condition. The latencies and source strengths of equivalent current dipoles (ECD over contralateral (right somatosensory cortex were analyzed. In the preschoolers who provided valid ECDs, the stimulus conditions induced an early-latency ECD occurring in between 60-68 ms mainly with an anterior direction. We further identified a middle-latency ECD in between 97-104 ms, which predominantly had a posterior direction. Finally, initial evidence was found for a late-latency ECD at about 139-151 ms again more often with an anterior direction. Differences were found in the source strengths of the middle-latency ECDs among the stimulus conditions. For the paired comparisons that could be formed, ECD source strength was more pronounced in the finger-touch condition than in the tactile-only and the toe-touch condition. Although more research is necessary to expand the data set, this suggests that visual information modulated preschool SEF. The finding that ECD source strength was higher when seen and felt touch occurred to the same body part, as compared to a different body part, might further indicate that connectivity between visual and tactile information is indexed in preschool somatosensory cortical activity, already in a somatotopic way.

  18. Mathematical impairment associated with high-contrast abnormalities in change detection and magnocellular visual evoked response. (United States)

    Jastrzebski, Nicola R; Crewther, Sheila G; Crewther, David P


    The cause of developmental dyscalculia, a specific deficit in acquisition of arithmetic skills, particularly of enumeration, has never been investigated with respect to the patency of the visual magnocellular system. Here, the question of dysfunction of the afferent magnocellular cortical input and its dorsal stream projections was tested directly using nonlinear analysis of the visual evoked potential (VEP) and through the psychophysical ability to rapidly detect visual change. A group of young adults with self-reported deficiencies of arithmetical ability, showed marked impairment in magnitude estimation and enumeration performance-though not in lexical decision reaction times when compared with an arithmetically capable group controlled for age and handedness. Multifocal nonlinear VEPs were recorded at low (24 %) and high (96 %) contrast. First- and second-order VEP kernels were comparable between groups at low contrast, but not at high contrast. The mathematically impaired group showed an abnormal lack of contrast saturation in the shortest latency first-order peak (N60) and a delayed P100 positivity in the first slice of the second-order kernel. Both features have previously been argued to be physiological markers of magnocellular function. Mathematically impaired participants also performed worse on a gap paradigm change detection for digit task showing increased reaction times for high-contrast stimuli but not for low-contrast stimuli compared with controls. The VEP results give direct evidence of abnormality in the occipital processing of magnocellular information in those with mathematical impairment. The anomalous high visual contrast physiological and psychophysical performance suggests an abnormality in the inhibitory processes that normally result in saturation of contrast gain in the magnocellular system.

  19. Somatosensory Evoked Field in Response to Visuotactile Stimulation in 3- to 4-Year-Old Children (United States)

    Remijn, Gerard B.; Kikuchi, Mitsuru; Shitamichi, Kiyomi; Ueno, Sanae; Yoshimura, Yuko; Nagao, Kikuko; Tsubokawa, Tsunehisa; Kojima, Haruyuki; Higashida, Haruhiro; Minabe, Yoshio


    A child-customized magnetoencephalography system was used to investigate somatosensory evoked field (SEF) in 3- to 4-year-old children. Three stimulus conditions were used in which the children received tactile-only stimulation to their left index finger or visuotactile stimulation. In the two visuotactile conditions, the children received tactile stimulation to their finger while they watched a video of tactile stimulation applied either to someone else’s finger (the finger-touch condition) or to someone else’s toe (the toe-touch condition). The latencies and source strengths of equivalent current dipoles (ECDs) over contralateral (right) somatosensory cortex were analyzed. In the preschoolers who provided valid ECDs, the stimulus conditions induced an early-latency ECD occurring between 60 and 68 ms mainly with an anterior direction. We further identified a middle-latency ECD between 97 and 104 ms, which predominantly had a posterior direction. Finally, initial evidence was found for a late-latency ECD at about 139–151 ms again more often with an anterior direction. Differences were found in the source strengths of the middle-latency ECDs among the stimulus conditions. For the paired comparisons that could be formed, ECD source strength was more pronounced in the finger-touch condition than in the tactile-only and the toe-touch conditions. Although more research is necessary to expand the data set, this suggests that visual information modulated preschool SEF. The finding that ECD source strength was higher when seen and felt touch occurred to the same body part, as compared to a different body part, might further indicate that connectivity between visual and tactile information is indexed in preschool somatosensory cortical activity, already in a somatotopic way. PMID:24715860

  20. Effect of subarachnoid hemorrhage on contractile responses and noradrenaline release evoked in cat cerebral arteries by histamine

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    Lobato, R.D.; Marin, J.; Salaices, M.; Rico, M.L.; Sanchez, C.F.


    This study analyzes the changes induced by subarachnoid hemorrhage (SAH) on the contractile responses and the noradrenaline release evoked in cat cerebral arteries by histamine. The dose-dependent vasoconstriction induced by histamine on the cerebral arteries of normal cats was significantly reduced by diphenhydramine and phentolamine. When SAH was produced 3 and 7 days before the experiment, the histamine-induced vasoconstriction also decreased. Thereafter, a tendency to normalization in the contractile vascular responses was observed such that in 15 days after the hemorrhage it was not significantly different from that found in controls animals. The decrease in the contractile responses to histamine provoked by SAH was similar to that seen after pretreatment with intracisternal injections of 6-hydroxydopamine. The amount of radioactivity released by histamine following preincubation with /sup 3/H-noradrenaline from the cerebral arteries of cats exposed to SAH 3, 7, and 15 days before the experiment was significantly reduced when compared with controls. Moreover, the basal level of tritium release and the radioactivity retained at the end of the experiment were also decreased after SAH. Results indicate histamine releases noradrenaline from cat cerebral arteries, and SAH produce a transient denervation of the perivascular adrenergic nerve endings, which explained by the impairment of the indirect adrenergic mechanism involved in the overall contractile response elicited by this amine in cerebral arteries. Histamine does not seem to play a significant role in the production of the cerebral vasospasm occurring after SAH.

  1. Impedance changes recorded with scalp electrodes during visual evoked responses: implications for Electrical Impedance Tomography of fast neural activity. (United States)

    Gilad, O; Holder, D S


    Electrical Impedance Tomography (EIT) is a recently developed medical imaging method which could enable fast neural imaging in the brain by recording the resistance changes which occur as ion channels open during neuronal depolarization. In published studies in animal models with intracranial electrodes, changes of 0.005 to 3% have been reported but the amplitude of changes in the human is not known. The purpose of this work was to determine if resistance changes could be recorded non-invasively in humans during evoked activity which could form the basis for EIT of fast neural activity. Resistance was recorded with scalp electrodes during 2 Hz pattern visual evoked responses over 10 min using an insensible 1 Hz square wave constant current of 0.1-1 mA. Significant resistance decreases of 0.0010+/-0.0005% (0.30+/-0.15 microV, signal-to-noise ratio (SNR) of 2:1, n=16 recordings over 6 subjects) (mean+/-SE) were recorded. These are in broad agreement with modelling which estimated changes of 0.0039+/-0.0034% (1.03+/-0.75 microV) using an anatomically realistic finite element model. This is the first demonstration of such changes in humans and so encourages the belief that EIT could be used for neural imaging. Unfortunately, the signal-to-noise ratio was not sufficient to permit imaging at present because recording over multiple injection sites needed for imaging would require impractically long recording times. However, in the future, invasive imaging with intracranial electrodes in animal models or humans and improved signal processing or recording may still enable imaging; this would constitute a significant advance in neuroscience technology.

  2. Bradykinin Contributes to Sympathetic and Pressor Responses Evoked by Activation of Skeletal Muscle Afferents P2X in Heart Failure

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    Jihong Xing


    Full Text Available Background/Aims: Published data suggest that purinergic P2X receptors of muscle afferent nerves contribute to the enhanced sympathetic nervous activity (SNA and blood pressure (BP responses during static exercise in heart failure (HF. In this study, we examined engagement of bradykinin (BK in regulating responses of SNA and BP evoked by P2X stimulation in rats with HF. We further examined cellular mechanisms responsible for BK. We hypothesized that BK potentiates P2X currents of muscle dorsal root ganglion (DRG neurons, and this effect is greater in HF due to upregulation of BK kinin B2 and P2X3 receptor. As a result, BK amplifies muscle afferents P2X-mediated SNA and BP responses. Methods: Renal SNA and BP responses were recorded in control rats and rats with HF. Western Blot analysis and patch-clamp methods were employed to examine the receptor expression and function of DRG neurons involved in the effects of BK. Results: BK injected into the arterial blood supply of the hindlimb muscles heightened the reflex SNA and BP responses induced by P2X activation with α,β-methylene ATP to a greater degree in HF rats. In addition, HF upregulated the protein expression of kinin B2 and P2X3 in DRG and the prior application of BK increased the magnitude of α,β-methylene ATP-induced currents in muscle DRG neurons from HF rats. Conclusion: BK plays a facilitating role in modulating muscle afferent P2X-engaged reflex sympathetic and pressor responses. In HF, P2X responsivness is augmented due to increases in expression of kinin B2 and P2X3 receptors and P2X current activity.

  3. Extended High Frequency Audiometry in Polycystic Ovary Syndrome

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    Cuneyt Kucur


    and BMI of PCOS and control groups were comparable. Each subject was tested with low (250–2000 Hz, high (4000–8000 Hz, and extended high frequency audiometry (8000–20000. Hormonal and biochemical values including LH, LH/FSH, testosterone, fasting glucose, fasting insulin, HOMA-I, and CRP were calculated. Results. PCOS patients showed high levels of LH, LH/FSH, testosterone, fasting insulin, glucose, HOMA-I, and CRP levels. The hearing thresholds of the groups were similar at frequencies of 250, 500, 1000, 2000, and 4000 Hz; statistically significant difference was observed in 8000–14000 Hz in PCOS group compared to control group. Conclusion. PCOS patients have hearing impairment especially in extended high frequencies. Further studies are needed to help elucidate the mechanism behind hearing impairment in association with PCOS.

  4. Evoked potentials in multiple sclerosis. (United States)

    Kraft, George H


    Before the development of magnetic resonance imaging (MRI), evoked potentials (EPs)-visual evoked potentials, somatosensory evoked potentials, and brain stem auditory evoked responses-were commonly used to determine a second site of disease in patients being evaluated for possible multiple sclerosis (MS). The identification of an area of the central nervous system showing abnormal conduction was used to supplement the abnormal signs identified on the physical examination-thus identifying the "multiple" in MS. This article is a brief overview of additional ways in which central nervous system (CNS) physiology-as measured by EPs-can still contribute value in the management of MS in the era of MRIs.

  5. Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the Nucleus CI24M cochlear implant system.

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    Cafarelli-Dees, D.; Dillier, N.; Lai, W.K.; Wallenberg, E. von; Dijk, B. van; Akdas, F.; Aksit, M.; Batman, C.; Beynon, A.J.; Burdo, S.; Chanal, J.M.; Collet, L.; Conway, M.; Coudert, C.; Craddock, L.; Cullington, H.; Deggouj, N.; Fraysse, B.; Grabel, S.; Kiefer, J.; Kiss, J.G.; Lenarz, T.; Mair, A.; Maune, S.; Muller-Deile, J.; Piron, J.P.; Razza, S.; Tasche, C.; Thai-Van, H.; Toth, F.; Truy, E.; Uziel, A.; Smoorenburg, G.F.


    One hundred and forty-seven adult recipients of the Nucleus 24 cochlear implant system, from 13 different European countries, were tested using neural response telemetry to measure the electrically evoked compound action potential (ECAP), according to a standardised postoperative measurement procedu

  6. Recording of electrical-evoked responses from a remote field in the vestibular part of the eighth nerve. A preliminary technical report. (United States)

    Latkowski, B; Puzio, J


    The paper discusses the results of the author's own studies concerning the recording of electrical responses evoked from a remote field in the vestibular part of the eighth nerve. The studies are of experimental nature and they were carried out repetitively in guinea pigs. Particular attention is paid to an apparatus specially designed and constructed, permitting to obtain stimulation of adequate quality of vestibular organs, and to receive and average short (up to 10 ms) evoked vestibular potentials. Different variants of elimination of bioelectrical muscular disturbances and of the auditory pathway are proposed.

  7. Contribution of resolved and unresolved harmonic regions to brainstem speech-evoked responses in quiet and in background noise

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    M. Laroche


    Full Text Available Speech auditory brainstem responses (speech ABR reflect activity that is phase-locked to the harmonics of the fundamental frequency (F0 up to at least the first formant (F1. Recent evidence suggests that responses at F0 in the presence of noise are more robust than responses at F1, and are also dissociated in some learning-impaired children. Peripheral auditory processing can be broadly divided into resolved and unresolved harmonic regions. This study investigates the contribution of these two regions to the speech ABR, and their susceptibility to noise. We recorded, in quiet and in background white noise, evoked responses in twelve normal hearing adults in response to three variants of a synthetic vowel: i Allformants, which contains all first three formants, ii F1Only, which is dominated by resolved harmonics, and iii F2&F3Only, which is dominated by unresolved harmonics. There were no statistically significant differences in the response at F0 due to the three variants of the stimulus in quiet, nor did the noise affect this response with the Allformants and F1Only variants. On the other hand, the response at F0 with the F2&F3Only variant was significantly weaker in noise than with the two other variants (p<0.001. With the response at F1, there was no difference with the Allformants and F1Only variants in quiet, but was expectedly weaker with the F2&F3Only variant (p<0.01. The addition of noise significantly weakened the response at F1 with the F1Only variant (p<0.05, but this weakening only tended towards significance with the Allformants variant (p=0.07. The results of this study indicate that resolved and unresolved harmonics are processed in different but interacting pathways that converge in the upper brainstem. The results also support earlier work on the differential susceptibility of responses at F0 and F1 to added noise.

  8. Use of magnitude-squared coherence to identify the maximum driving response band of the somatosensory evoked potential

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    A.F.C. Infantosi


    Full Text Available The present study proposes to apply magnitude-squared coherence (MSC to the somatosensory evoked potential for identifying the maximum driving response band. EEG signals, leads [Fpz'-Cz'] and [C3'-C4'], were collected from two groups of normal volunteers, stimulated at the rate of 4.91 (G1: 26 volunteers and 5.13 Hz (G2: 18 volunteers. About 1400 stimuli were applied to the right tibial nerve at the motor threshold level. After applying the anti-aliasing filter, the signals were digitized and then further low-pass filtered (200 Hz, 6th order Butterworth and zero-phase. Based on the rejection of the null hypothesis of response absence (MSC(f > 0.0060 with 500 epochs and the level of significance set at a = 0.05, the beta and gamma bands, 15-66 Hz, were identified as the maximum driving response band. Taking both leads together ("logical-OR detector", with a false-alarm rate of a = 0.05, and hence a = 0.0253 for each derivation, the detection exceeded 70% for all multiples of the stimulation frequency within this range. Similar performance was achieved for MSC of both leads but at 15, 25, 35, and 40 Hz. Moreover, the response was detected in [C3'-C4'] at 35.9 Hz and in [Fpz'-Cz'] at 46.2 Hz for all members of G2. Using the "logical-OR detector" procedure, the response was detected at the 7th multiple of the stimulation frequency for the series as a whole (considering both groups. Based on these findings, the MSC technique may be used for monitoring purposes.

  9. Visual evoked response changes following intrathecal injection of water-soluble contrast media: a possible method of assessing neurotoxicity and a comparison of metrizamide and iopamidol. (United States)

    Broadbridge, A T; Bayliss, S G; Firth, R; Farrell, G


    An investigation was carried out to ascertain if there was a change in visual evoked responses following the intrathecal injection of water-soluble contrast media for myeloradiculography and if this change provided an indication of neurotoxicity as assessed by the onset of headache during a period of 20 h following the radiological examination. The patients were unselected and examined, when facilities for measuring the visual evoked response were available, immediately before and at 1 and 20 h after the examination. Control readings were carried out before, 1 h and 20 h after lumbar puncture in patients who did not have an injection of contrast medium. The first 25 patients in the series received metrizamide; when iopamidol became available a change to the newer medium was made and iopamidol was used on all subsequent patients. All the injections were carried out by the same radiologist and the patients were kept in hospital overnight and interviewed the next morning, avoiding a specific reference to headache unless the patient denied all symptoms. It was found that the latency of the visual evoked response was affected in some cases by the presence of contrast medium in the cerebrospinal fluid and that there was a correlation between the severity of headaches and the delay in the visual evoked response at the 20 h post-myelogram measurement, but not at 1 h after the examination. It would appear, therefore, that the visual evoked response measurement is a valid method of assessing, in the short term, the neurotoxicity of intrathecal water-soluble contrast media and that, on this evidence, iopamidol is less neurotoxic than metrizamide. We are not aware of any long-term complications resulting from the use of either contrast medium.

  10. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;


    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...

  11. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;


    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  12. Contribuição do potencial evocado auditivo em pacientes com vertigem Results of brainstem evoked response in patients with vestibular complaints

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    Gisiane Munaro


    -sectional, retrospective, observational study, held with 56 dizzy patients assessed by means of audiometry, vecto-electronystagmography and brainstem evoked auditory potential, broken down into Group A, with 31 normal-hearing individuals and Group B with 25 hearing loss patients, compared to the control group made up of ten normal-hearing asymptomatic individuals. RESULTS: Patients from groups A and B were compared to the Control Group, although with values within the normal range. A common finding for both groups was the lack of wave I at 80 dBHL and it happened bilaterally in four individuals (12.9% and unilaterally in three (9.6% for Group A; and bilaterally in eight individuals from Group B (32%. In the two cases in which vecto-electronystagmography showed central vestibular alteration, there were no changes to the evoked potential parameters. CONCLUSION: patients with vertigo, normal-hearing and hearing loss individuals had increased absolute latencies when compared to the Control Group

  13. Long-term evolution of brainstem electrical evoked responses to sound after restricted ablation of the auditory cortex.

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    Verónica Lamas

    Full Text Available INTRODUCTION: This study aimed to assess the top-down control of sound processing in the auditory brainstem of rats. Short latency evoked responses were analyzed after unilateral or bilateral ablation of auditory cortex. This experimental paradigm was also used towards analyzing the long-term evolution of post-lesion plasticity in the auditory system and its ability to self-repair. METHOD: Auditory cortex lesions were performed in rats by stereotactically guided fine-needle aspiration of the cerebrocortical surface. Auditory Brainstem Responses (ABR were recorded at post-surgery day (PSD 1, 7, 15 and 30. Recordings were performed under closed-field conditions, using click trains at different sound intensity levels, followed by statistical analysis of threshold values and ABR amplitude and latency variables. Subsequently, brains were sectioned and immunostained for GAD and parvalbumin to assess the location and extent of lesions accurately. RESULTS: Alterations in ABR variables depended on the type of lesion and post-surgery time of ABR recordings. Accordingly, bilateral ablations caused a statistically significant increase in thresholds at PSD1 and 7 and a decrease in waves amplitudes at PSD1 that recover at PSD7. No effects on latency were noted at PSD1 and 7, whilst recordings at PSD15 and 30 showed statistically significant decreases in latency. Conversely, unilateral ablations had no effect on auditory thresholds or latencies, while wave amplitudes only decreased at PSD1 strictly in the ipsilateral ear. CONCLUSION: Post-lesion plasticity in the auditory system acts in two time periods: short-term period of decreased sound sensitivity (until PSD7, most likely resulting from axonal degeneration; and a long-term period (up to PSD7, with changes in latency responses and recovery of thresholds and amplitudes values. The cerebral cortex may have a net positive gain on the auditory pathway response to sound.

  14. Characterisation of the p53-mediated cellular responses evoked in primary mouse cells following exposure to ultraviolet radiation.

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    Gillian D McFeat

    Full Text Available Exposure to ultraviolet (UV light can cause significant damage to mammalian cells and, although the spectrum of damage produced varies with the wavelength of UV, all parts of the UV spectrum are recognised as being detrimental to human health. Characterising the cellular response to different wavelengths of UV therefore remains an important aim so that risks and their moderation can be evaluated, in particular in relation to the initiation of skin cancer. The p53 tumour suppressor protein is central to the cellular response that protects the genome from damage by external agents such as UV, thus reducing the risk of tumorigenesis. In response to a variety of DNA damaging agents including UV light, wild-type p53 plays a role in mediating cell-cycle arrest, facilitating apoptosis and stimulating repair processes, all of which prevent the propagation of potentially mutagenic defects. In this study we examined the induction of p53 protein and its influence on the survival of primary mouse fibroblasts exposed to different wavelengths of UV light. UVC was found to elevate p53 protein and its sequence specific DNA binding capacity. Unexpectedly, UVA treatment failed to induce p53 protein accumulation or sequence specific DNA binding. Despite this, UVA exposure of wild-type cells induced a p53 dependent G1 cell cycle arrest followed by a wave of p53 dependent apoptosis, peaking 12 hours post-insult. Thus, it is demonstrated that the elements of the p53 cellular response evoked by exposure to UV radiation are wavelength dependent. Furthermore, the interrelationship between various endpoints is complex and not easily predictable. This has important implications not only for understanding the mode of action of p53 but also for the use of molecular endpoints in quantifying exposure to different wavelengths of UV in the context of human health protection.

  15. A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

    DEFF Research Database (Denmark)

    Vianna, Lauro C; Fadel, Paul J; Secher, Niels H


    A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response...... of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular...... resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions...

  16. State-dependent variations in brainstem auditory evoked responses in human subjects. (United States)

    Sersen, E A; Majkowski, J; Clausen, J; Heaney, G M


    BAERs from 16 subjects during 3 sessions varied in the latency or amplitude of some components depending upon level of arousal as indicated by EEG patterns. There was a general tendency for activation to produce the fastest responses with the largest amplitudes and for drowsiness to produce the slowest responses with the smallest amplitudes. The latency of P2 was significantly prolonged during drowsiness, relative to those during relaxation or activation. For right-ear stimulation, P5 latency was longest during drowsiness, and shortest during activation while for left-ear stimulation the shortest latency occurred during relaxation. The amplitudes of Wave II and Wave VII were significantly smaller during drowsiness than during activation. Although the differences were below the level of clinical significance, the data indicate a modification in the characteristics of brainstem transmission as a function of concurrent activity in other brain areas.

  17. A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans. (United States)

    Vianna, Lauro C; Fadel, Paul J; Secher, Niels H; Fisher, James P


    A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions and following cholinergic blockade (glycopyrrolate). Under control conditions, isometric handgrip elicited an initial increase in BP (+5 ± 2 mmHg at 3 s and +3 ± 1 mmHg at 10 s, P mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans.

  18. Effects of fractionated doses of fast neutrons or photons on the canine brain: evaluation by computerized tomography and evoked response recording

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, E.W.; Davis, D.O.; Gaskill, J.W.; Deye, J.A.; Fisher, M.P.; Sloan, G.E.; Rogers, C.C.


    The use of fast neutrons in the treatment of cancer necessitates a knowledge of the normal tissue responses. This study was designed to compare the late effects of fractionated doses of fast neutrons with fractionated doses of photons on canine brains by evoked response recording and viewing computerized tomograms (CT). A relative biological effectiveness (RBE) of 4 was obtained for normal brain tissue assessed by mortality and onset of neurologic symptoms. Every three months post-irradiation, visual and sensory evoked responses were recorded. Changes over time appeared to be minimal; however, computerized tomographs showed marked brain shrinkage. A method of quantitating cerebrospinal fluid and parenchymal volumes from scans is described and future use of these CT ratios to generate dose response curves and RBE values is postulated.

  19. Visually evoked hemodynamical response and assessment of neurovascular coupling in the optic nerve and retina. (United States)

    Riva, Charles E; Logean, Eric; Falsini, Benedetto


    The retina and optic nerve are both optically accessible parts of the central nervous system. They represent, therefore, highly valuable tissues for studies of the intrinsic physiological mechanism postulated more than 100 years ago by Roy and Sherrington, by which neural activity is coupled to blood flow and metabolism. This article describes a series of animal and human studies that explored the changes in hemodynamics and oxygenation in the retina and optic nerve in response to increased neural activity, as well as the mechanisms underlying these changes. It starts with a brief review of techniques used to assess changes in neural activity, hemodynamics, metabolism and tissue concentration of various potential mediators and modulators of the coupling. We then review: (a) the characteristics of the flicker-induced hemodynamical response in different regions of the eye, starting with the optic nerve, the region predominantly studied; (b) the effect of varying the stimulus parameters, such as modulation depth, frequency, luminance, color ratio, area of stimulation, site of measurement and others, on this response; (c) data on activity-induced intrinsic reflectance and functional magnetic resonance imaging signals from the optic nerve and retina. The data undeniably demonstrate that visual stimulation is a powerful modulator of retinal and optic nerve blood flow. Exploring the relationship between vasoactivity and metabolic changes on one side and corresponding neural activity changes on the other confirms the existence of a neurovascular/neurometabolic coupling in the neural tissue of the eye fundus and reveals that the mechanism underlying this coupling is complex and multi-factorial. The importance of fully exploiting the potential of the activity-induced vascular changes in the assessment of the pathophysiology of ocular diseases motivated studies aimed at identifying potential mediators and modulators of the functional hyperemia, as well as conditions

  20. Effect of serum cholesterol levels on meta-chlorophenylpiperazine-evoked neuroendocrine responses in healthy subjects. (United States)

    Terao, T; Yoshimura, R; Ohmori, O; Takano, T; Takahashi, N; Iwata, N; Suzuki, T; Abe, K


    This study was undertaken to test the hypothesis that serum cholesterol levels might be associated with serotonergic receptor function. The participants were 10 healthy male subjects. After an overnight fast, the subjects received meta-chlorophenylpiperazine (m-CPP) or identical placebo capsules orally in a randomized, double-blind, cross-over design. Blood was obtained for measurement of prolactin, cortisol, adrenocorticotropic hormone (ACTH), and cholesterol. There were some significantly positive correlations between serum cholesterol levels and hormonal responses to m-CPP administration. These results suggest that serum cholesterol levels may be positively associated with serotonergic receptor function.

  1. High frequency switched-mode stimulation can evoke postsynaptic responses in cerebellar principal neurons

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    Marijn Van Dongen


    Full Text Available This paper investigates the efficacy of high frequency switched-mode neural stimulation. Instead of using a constant stimulation amplitude, the stimulus is switched on and off repeatedly with a high frequency (up to 100kHz duty cycled signal. By means of tissue modeling that includes the dynamic properties of both the tissue material as well as the axon membrane, it is first shown that switched-mode stimulation depolarizes the cell membrane in a similar way as classical constant amplitude stimulation.These findings are subsequently verified using in vitro experiments in which the response of a Purkinje cell is measured due to a stimulation signal in the molecular layer of the cerebellum of a mouse. For this purpose a stimulator circuit is developed that is able to produce a monophasic high frequency switched-mode stimulation signal. The results confirm the modeling by showing that switched-mode stimulation is able to induce similar responses in the Purkinje cell as classical stimulation using a constant current source. This conclusion opens up possibilities for novel stimulation designs that can improve the performance of the stimulator circuitry. Care has to be taken to avoid losses in the system due to the higher operating frequency.

  2. Evoked response denoising using nonlinear diffusion filtering of single-trial matrix representations. (United States)

    Mustaffa, Izadora; Trenado, Carlos; Schwerdtfeger, Karsten; Strauss, Daniel J


    Recent progress in mathematical image processing shows a remarkable success when applying numerical methods to ill-posed partial differential equations (PDE). In particular, nonlinear diffusion filtering (NDF)process is an approach that belongs to such family of differential equations. It has been successfully applied in many recent methods for image processing and computer vision areas, particularly in denoising, smoothing, segmentation, and restoration. In this paper we focus on a novel NDF application, namely denoising of single-trials of auditory brainstem responses (ABRs) and the analysis of transcranial magnetic stimulation (TMS) responses.We show that by applying NDF on a matrix-form image of single-trials, we were able to denoise the single-trials, resulting in a better extraction of information over the ongoing experiment; morphology, eg. the latency of the single-trials according to different stimuli paradigms at different stimulation intensity levels. It is concluded that NDF represents a novel and useful approach for the analysis of single-trials in brain imaging.

  3. Predictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma. (United States)

    Bouwes, Aline; Binnekade, Jan M; Verbaan, Bart W; Zandbergen, Eveline G J; Koelman, Johannes H T M; Weinstein, Henry C; Hijdra, Albert; Horn, Janneke


    Bilateral absence of cortical N20 responses of median nerve somatosensory evoked potentials (SEP) predicts poor neurological outcome in postanoxic coma after cardiopulmonary resuscitation (CPR). Although SEP is easy to perform and available in most hospitals, it is worthwhile to know how neurological signs are associated with SEP results. The aim of this study was to investigate whether specific clinical neurological signs are associated with either an absent or a present median nerve SEP in patients after CPR. Data from the previously published multicenter prospective cohort study PROPAC (prognosis in postanoxic coma, 2000-2003) were used. Neurological examination, consisting of Glasgow Coma Score (GCS) and brain stem reflexes, and SEP were performed 24, 48, and 72 h after CPR. Positive predictive values for predicting absent and present SEP, as well as diagnostic accuracy were calculated. Data of 407 patients were included. Of the 781 SEPs performed, N20 s were present in 401, bilaterally absent in 299, and 81 SEPs were technically undeterminable. The highest positive predictive values (0.63-0.91) for an absent SEP were found for absent pupillary light responses. The highest positive predictive values (0.71-0.83) for a present SEP were found for motor scores of withdrawal to painful stimuli or better. Multivariate analyses showed a fair diagnostic accuracy (0.78) for neurological examination in predicting an absent or present SEP at 48 or 72 h after CPR. This study shows that neurological examination cannot reliably predict absent or present cortical N20 responses in median nerve SEPs in patients after CPR.

  4. Effects of glutamate receptor agonists on the P13 auditory evoked potential and startle response in the rat

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    Christen eSimon


    Full Text Available The P13 potential is the rodent equivalent of the P50 potential, which is an evoked response recorded at the vertex (Vx 50 msec following an auditory stimulus in humans. Both the P13 and P50 potentials are only present during waking and rapid eye movement (REM sleep, and are considered to be measures of level of arousal. The source of the P13 and P50 potentials appears to be the pedunculopontine nucleus (PPN, a brainstem nucleus with indirect ascending projections to the cortex through the intralaminar thalamus (ILT, mediating arousal, and descending inhibitory projections to the caudal pontine reticular formation (CPRF, which mediates the auditory startle response (SR. We tested the hypothesis that intracranial microinjection (ICM of glutamate (GLU or GLU receptor agonists will increase the activity of PPN neurons, resulting in an increased P13 potential response, and decreased SR due to inhibitory projections from the PPN to the CPRF, in freely moving animals. Cannulae were inserted into the PPN to inject neuroactive agents, screws were inserted into the Vx in order to record the P13 potential, and electrodes inserted into the dorsal nuchal muscle to record electromyograms (EMGs and SR amplitude. Our results showed that ICM of GLU into the PPN dose-dependently increased the amplitude of the P13 potential and decreased the amplitude of the SR. Similarly, ICM of NMDA or KA into the PPN increased the amplitude of the P13 potential. These findings indicate that glutamatergic input to the PPN plays a role in arousal control in vivo, and changes in glutamatergic input, or excitability of PPN neurons, could be implicated in a number of neuropsychiatric disorders with the common symptoms of hyperarousal and REM sleep dysregulation.

  5. Sex-specific automatic responses to infant cries: TMS reveals greater excitability in females than males in motor evoked potentials

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    Irene eMessina


    Full Text Available Neuroimaging reveals that infant cries activate parts of the premotor cortical system. To validate this effect in a more direct way, we used event-related transcranial magnetic stimulation (TMS. Here, we investigated the presence and the time course of modulation of motor cortex excitability in young adults who listened to infant cries. Specifically, we recorded motor evoked potentials (MEPs from the biceps brachii (BB and interosseus dorsalis primus (ID1 muscles as produced by TMS delivered from 0 to 250 ms from sound onset in six steps of 50 ms in 10 females and 10 males. We observed an excitatory modulation of MEPs at 100 ms from the onset of the infant cry specific to females and to the ID1 muscle. We regard this modulation as a response to natural cry sounds because it was delayed, attenuated to stimuli increasingly different from natural cry, and was absent in a separate group of females who listened to non-cry stimuli physically matched to natural infant cries. Furthermore, the 100-ms latency of this modulation is not compatible with a voluntary reaction to the stimulus but suggests an automatic, bottom-up audiomotor association. The brains of adult females appear to be tuned to respond to infant cries with automatic motor excitation. This effect may reflect the greater and longstanding burden on females in caregiving infants.

  6. Comparing the Performance of Popular MEG/EEG Artifact Correction Methods in an Evoked-Response Study

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    Niels Trusbak Haumann


    Full Text Available We here compared results achieved by applying popular methods for reducing artifacts in magnetoencephalography (MEG and electroencephalography (EEG recordings of the auditory evoked Mismatch Negativity (MMN responses in healthy adult subjects. We compared the Signal Space Separation (SSS and temporal SSS (tSSS methods for reducing noise from external and nearby sources. Our results showed that tSSS reduces the interference level more reliably than plain SSS, particularly for MEG gradiometers, also for healthy subjects not wearing strongly interfering magnetic material. Therefore, tSSS is recommended over SSS. Furthermore, we found that better artifact correction is achieved by applying Independent Component Analysis (ICA in comparison to Signal Space Projection (SSP. Although SSP reduces the baseline noise level more than ICA, SSP also significantly reduces the signal—slightly more than it reduces the artifacts interfering with the signal. However, ICA also adds noise, or correction errors, to the waveform when the signal-to-noise ratio (SNR in the original data is relatively low—in particular to EEG and to MEG magnetometer data. In conclusion, ICA is recommended over SSP, but one should be careful when applying ICA to reduce artifacts on neurophysiological data with relatively low SNR.

  7. Comparing the Performance of Popular MEG/EEG Artifact Correction Methods in an Evoked-Response Study (United States)

    Kliuchko, Marina; Vuust, Peter


    We here compared results achieved by applying popular methods for reducing artifacts in magnetoencephalography (MEG) and electroencephalography (EEG) recordings of the auditory evoked Mismatch Negativity (MMN) responses in healthy adult subjects. We compared the Signal Space Separation (SSS) and temporal SSS (tSSS) methods for reducing noise from external and nearby sources. Our results showed that tSSS reduces the interference level more reliably than plain SSS, particularly for MEG gradiometers, also for healthy subjects not wearing strongly interfering magnetic material. Therefore, tSSS is recommended over SSS. Furthermore, we found that better artifact correction is achieved by applying Independent Component Analysis (ICA) in comparison to Signal Space Projection (SSP). Although SSP reduces the baseline noise level more than ICA, SSP also significantly reduces the signal—slightly more than it reduces the artifacts interfering with the signal. However, ICA also adds noise, or correction errors, to the waveform when the signal-to-noise ratio (SNR) in the original data is relatively low—in particular to EEG and to MEG magnetometer data. In conclusion, ICA is recommended over SSP, but one should be careful when applying ICA to reduce artifacts on neurophysiological data with relatively low SNR. PMID:27524998

  8. Auditory cortical responses evoked by pure tones in healthy and sensorineural hearing loss subjects: functional MRI and magnetoencephalography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-ting; GENG Zuo-jun; ZHANG Quan; LI Wei; ZHANG Jing


    hearing loss and the healthy subjects, the most evident audio evoked fields activated by pure tone were N100m,which located precisely on the Heschl's gyms. Compared with the hearing loss subjects, N100m of the healthy subjects was stronger and had longer latencies in fight hemisphere.Conclusions Under proper pure tone stimulus the activation of auditory cortex can be elicited both in the healthy and the sensorineural hearing loss subjects. Either at objective equivalent stimuli or at subjectively perceived equivalent stimuli, the auditory responses were more intensive in healthy subjects than hearing loss subjects. The tone stimuli were processed in a network in human brain and there was an intrinsic relation between the auditory and visual cortex. Blood oxygen level dependent fMRI and magnetoencephalography could reinforce each other.

  9. Sensorineural hearing loss with brainstem auditory evoked responses changes in homozygote and heterozygote sickle cell patients in Guadeloupe (France). (United States)

    Jovanovic-Bateman, L; Hedreville, R


    This prospective study involved 79 homozygote and heterozygote sickle cell anaemia patients (16 to 50 years old) and a control group of 40 people.All patients underwent ENT, audiological and brainstem auditory evoked responses (BSER) examinations in order to evaluate the incidence of sensorineural hearing loss (SNHL), to identify the changes at the level of the cochlear nerve and the central pathways, and to determine the most vulnerable group, in order to intervene with early prevention and rehabilitation for this condition.A hearing loss of greater than 20 dB at two or more frequencies was found in 36 (45.57 per cent) sickle cell patients (19 (47.22 per cent) HbSC patients and 17 (43.59 per cent) HbSS patients) and three (7.5 per cent) members of the control group. Homozygote and heterozygote patients, as well as both sexes, were equally affected. Bilateral hearing loss occurred in 19 (52.78 per cent) patients, unilateral right-sided hearing loss in five (13.89 per cent) patients and unilateral left-sided hearing loss in 12 (33.33 per cent) patients. Brainstem auditory evoked potential demonstrated a prolonged I-V (III-V) interpeak latency in 13 (25.35 per cent) sickle cell patients (11 men (eight with HbSS) and two women). The hearing loss in HbSS patients was neural in nature and of earlier onset; the hearing loss in HbSC patients was usually cochlear in nature and of later onset. Despite high medical standards and 100 per cent social security cover, the high incidence of SNHL in our sickle cell affected patients (the majority with the Benin haplotype) was probably due to their specific haematological profile and to the original geographical distribution of the disease in the tropics. Our results highlight the necessity for early and regular hearing assessment of sickle cell patients, including BSER examination, especially in male patients with SNHL.

  10. Cellular Responses Evoked by Different Surface Characteristics of Intraosseous Titanium Implants

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    Liviu Feller


    Full Text Available The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration.

  11. In vivo tactile stimulation-evoked responses in Caenorhabditis elegans amphid sheath glia.

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    Gang Ding

    Full Text Available Glial cells are important components of the nervous system. However, how they respond to physiological stimuli in vivo remains largely unknown. In this study, we investigated the electrophysiological activities and Ca2+ responses of the C. elegans amphid sheath glia (AMsh glia to tactile stimulation in vivo. We recorded robust inward currents and Ca2+ elevation in the AMsh cell with the delivery of tactile stimuli of varying displacements to the nose tip of the worm. Compared to the adjacent mechanoreceptor ASH neuron, the AMsh cell showed greater sensitivity to tactile stimulation. Amiloride, an epithelial Na+ channel blocker, blocked the touch-induced currents and Ca2+ signaling in the ASH neuron, but not those in the AMsh cell. Taken together, our results revealed that AMsh glial cells actively respond to in vivo tactile stimulation and likely function cell-autonomously as mechanoreceptors.

  12. Newborn hearing screening by transient evoked otoacoustic emissions: analysis of response as a function of risk factors. (United States)

    De Capua, B; De Felice, C; Costantini, D; Bagnoli, F; Passali, D


    Hearing loss can be considered as the most common birth defect. Early detection of hearing loss by screening at, or shortly after, birth and appropriate intervention are critical to speech, language and cognitive development. In the present study, the characteristics of Transient Evoked Otoacoustic Emissions have been evaluated as a function of known pre- and perinatal risk factors for hearing loss. All newborns were screened for hearing loss using a physiologic test of hearing function, the Transient Evoked Otoacoustic Emissions. A total of 532 consecutive newborn infants received binaural Transient Evoked Otoacoustic Emission testing (262 males, 270 females; mean gestational age 39.2 +/- 2.1 weeks, range 26-43; birth weight: 3,240 +/- 550 g, range 910-4,780). The population examined comprised 448 control infants and 84 high-risk for hearing loss infants (Joint Committee on Infant Hearing 1994 criteria). All Transient Evoked Otoacoustic Emission recordings were performed at comparable postconceptional ages. Audiological screening by Transient Evoked Otoacoustic Emission recording showed an overall 100% sensitivity, 99.02% specificity, with negative and positive predictive values of 100% and 62.5%, respectively. As compared to controls, high-risk infants showed: 1. increased rates of Fail-1 (Transient Evoked Otoacoustic Emissions absent at first examination, 21.4% vs 9.8%, p = 0.004), Fail-2 (Transient Evoked Otoacoustic Emissions absent on retesting: 8.64% vs 1.37%, p = 0.0014), false positives (Transient Evoked Otoacoustic Emissions absent/V wave present: 3.7% vs 0.46%, p = 0.029) and true positives (Transient Evoked Otoacoustic Emissions absent, V wave absent: 2.47% or 24.5 per 1,000 live births vs 0.22% or 2.2 per 1,000 live births, p = 0.013); 2. significantly reduced Transient Evoked Otoacoustic Emission intensity in the 0.7-1 kHz (right side) and 1-2 kHz (left side) frequency ranges. Multivariate logistic regression analysis showed a significant positive

  13. Comparison of icilin- and cold-evoked responses of spinal neurones, and their modulation of mechanical activity, in a model of neuropathic pain. (United States)

    Brignell, Jennifer L; Chapman, Victoria; Kendall, David A


    Cold allodynia is a poorly understood symptom of neuropathic pain. Two members of the transient receptor potential (TRP) family of proteins, TRPM8 and TRPA1, may contribute to cold somatosensation. The aim of the present study was to investigate the usefulness of icilin as a pharmacological tool to study primary afferent fibre responses to cold stimuli and to determine whether there are differences in the responses of spinal neurones to cooling of peripheral receptive fields in control versus neuropathic rats. The effects of icilin, a TRPM8 and TRPA1 agonist, on intracellular Ca(2+) ([Ca(2+)](i)) responses of small diameter adult dorsal root ganglia (DRG) neurones were determined. Icilin (10 nM-10 microM) produced a concentration-related increase in [Ca(2+)](i) in DRG neurones, which was attenuated by the non-selective TRP channel antagonist ruthenium red (10 microM). In vivo electrophysiology in naïve, sham-operated and SNL rats demonstrated that application of ice to receptive fields evoked firing of wide dynamic range (WDR) neurones, which was significantly greater in SNL rats than naïve and sham-operated rats. Intraplantar injection of icilin did not evoke firing of WDR neurones in naïve, sham-operated or SNL rats but inhibited mechanically-evoked responses of WDR neurones in naïve and sham-operated rats, whilst facilitating mechanically-evoked responses in SNL rats. Icilin increased both innocuous (sham-operated and SNL rats) and noxious (SNL rats) receptive field sizes of WDR neurones. Our data suggests that icilin modulates the mechanosensitivity of dorsal horn neurones. The differing effects of ice and icilin on dorsal horn neurones indicate different mechanisms of action.

  14. Conventional and cross-correlation brain-stem auditory evoked responses in the white leghorn chick: rate manipulations (United States)

    Burkard, R.; Jones, S.; Jones, T.


    Rate-dependent changes in the chick brain-stem auditory evoked response (BAER) using conventional averaging and a cross-correlation technique were investigated. Five 15- to 19-day-old white leghorn chicks were anesthetized with Chloropent. In each chick, the left ear was acoustically stimulated. Electrical pulses of 0.1-ms duration were shaped, attenuated, and passed through a current driver to an Etymotic ER-2 which was sealed in the ear canal. Electrical activity from stainless-steel electrodes was amplified, filtered (300-3000 Hz) and digitized at 20 kHz. Click levels included 70 and 90 dB peSPL. In each animal, conventional BAERs were obtained at rates ranging from 5 to 90 Hz. BAERs were also obtained using a cross-correlation technique involving pseudorandom pulse sequences called maximum length sequences (MLSs). The minimum time between pulses, called the minimum pulse interval (MPI), ranged from 0.5 to 6 ms. Two BAERs were obtained for each condition. Dependent variables included the latency and amplitude of the cochlear microphonic (CM), wave 2 and wave 3. BAERs were observed in all chicks, for all level by rate combinations for both conventional and MLS BAERs. There was no effect of click level or rate on the latency of the CM. The latency of waves 2 and 3 increased with decreasing click level and increasing rate. CM amplitude decreased with decreasing click level, but was not influenced by click rate for the 70 dB peSPL condition. For the 90 dB peSPL click, CM amplitude was uninfluenced by click rate for conventional averaging. For MLS BAERs, CM amplitude was similar to conventional averaging for longer MPIs.(ABSTRACT TRUNCATED AT 250 WORDS).

  15. Stimulus dependency of object-evoked responses in human visual cortex: an inverse problem for category specificity.

    Directory of Open Access Journals (Sweden)

    Britta Graewe

    Full Text Available Many studies have linked the processing of different object categories to specific event-related potentials (ERPs such as the face-specific N170. Despite reports showing that object-related ERPs are influenced by visual stimulus features, there is consensus that these components primarily reflect categorical aspects of the stimuli. Here, we re-investigated this idea by systematically measuring the effects of visual feature manipulations on ERP responses elicited by both structure-from-motion (SFM-defined and luminance-defined object stimuli. SFM objects elicited a novel component at 200-250 ms (N250 over parietal and posterior temporal sites. We found, however, that the N250 amplitude was unaffected by restructuring SFM stimuli into meaningless objects based on identical visual cues. This suggests that this N250 peak was not uniquely linked to categorical aspects of the objects, but is strongly determined by visual stimulus features. We provide strong support for this hypothesis by parametrically manipulating the depth range of both SFM- and luminance-defined object stimuli and showing that the N250 evoked by SFM stimuli as well as the well-known N170 to static faces were sensitive to this manipulation. Importantly, this effect could not be attributed to compromised object categorization in low depth stimuli, confirming a strong impact of visual stimulus features on object-related ERP signals. As ERP components linked with visual categorical object perception are likely determined by multiple stimulus features, this creates an interesting inverse problem when deriving specific perceptual processes from variations in ERP components.

  16. Transiently Evoked Otoacoustic Emissions in Children with Otitis Media with Effusion

    Directory of Open Access Journals (Sweden)

    Dimitris G. Balatsouras


    Full Text Available Introduction. Otitis media with effusion is a common pediatric disease whose diagnosis is based on pneumatic otoscopy, pure-tone audiometry, and tympanometry. The aim of this study was to evaluate transiently evoked otoacoustic emissions in the diagnosis of otitis media with effusion as compared to tympanometry. Patients and Methods. 38 children with bilateral otitis media with effusion were studied. 40 normal children of similar age and sex were used as controls. All subjects underwent pneumatic otoscopy, standard pure-tone audiometry, tympanometry, and transiently evoked otoacoustic emissions. Results. In the group of children with bilateral otitis media, transiently evoked otoacoustic emissions were absent in 51 ears (67%. In the remaining 25 ears (33% the mean emission amplitude was reduced, as compared to the mean value of the control group. Conclusions. Transiently evoked otoacoustic emissions should be included in the diagnostic workup of otitis media with effusion because it is a fast, reliable, and objective test. Transiently evoked otoacoustic emissions should always be used in conjunction with tympanometry, because a more meaningful interpretation of transiently evoked otoacoustic emissions measures is possible.

  17. Repeated forced swim stress differentially affects formalin-evoked nociceptive behaviour and the endocannabinoid system in stress normo-responsive and stress hyper-responsive rat strains. (United States)

    Jennings, Elaine M; Okine, Bright N; Olango, Weredeselam M; Roche, Michelle; Finn, David P


    Repeated exposure to a homotypic stressor such as forced swimming enhances nociceptive responding in rats. However, the influence of genetic background on this stress-induced hyperalgesia is poorly understood. The aim of the present study was to compare the effects of repeated forced swim stress on nociceptive responding in Sprague-Dawley (SD) rats versus the Wistar Kyoto (WKY) rat strain, a genetic background that is susceptible to stress, negative affect and hyperalgesia. Given the well-documented role of the endocannabinoid system in stress and pain, we investigated associated alterations in endocannabinoid signalling in the dorsal horn of the spinal cord and amygdala. In SD rats, repeated forced swim stress for 10 days was associated with enhanced late phase formalin-evoked nociceptive behaviour, compared with naive, non-stressed SD controls. In contrast, WKY rats exposed to 10 days of swim stress displayed reduced late phase formalin-evoked nociceptive behaviour. Swim stress increased levels of monoacylglycerol lipase (MAGL) mRNA in the ipsilateral side of the dorsal spinal cord of SD rats, an effect not observed in WKY rats. In the amygdala, swim stress reduced anandamide (AEA) levels in the contralateral amygdala of SD rats, but not WKY rats. Additional within-strain differences in levels of CB1 receptor and fatty acid amide hydrolase (FAAH) mRNA and levels of 2-arachidonylglycerol (2-AG) were observed between the ipsilateral and contralateral sides of the dorsal horn and/or amygdala. These data indicate that the effects of repeated stress on inflammatory pain-related behaviour are different in two rat strains that differ with respect to stress responsivity and affective state and implicate the endocannabinoid system in the spinal cord and amygdala in these differences.

  18. Correlation of the CT analysis and audiometry in otosclerosis

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    Kiyomizu, Kensuke; Tono, Tetsuya; Yang, Dewen; Haruta, Atsushi; Kodama, Takao; Kato, Eiji; Komune, Shizuo [Miyazaki Medical Coll., Kiyotake (Japan)


    Thirty-three patients (62 ears) with surgically confirmed otosclerosis underwent a preoperative CT examination in order to determine the presence of any correlation between the audiometric and CT findings. Based on the CT findings, the ears were classified into five groups as follows: group A; 25 ears (40.3%) with normal CT findings, group B1; 15 ears (24.2%) with demineralization in the region of the fissula antefenestram, group B2; 12 ears (19.4%) with demineralization around the anterior to the oval window, group B3; 4 ears (6.5%) with demineralization surrounding the cochlea, and group C; 6 ears (9.7%) with thick anterior and posterior plaques. The expansion of demineralization led to an increase in average bone conduction hearing level: group A ; 27.1 dB, group B1; 30.6 dB, group B2; 34.6 dB, group B3; 36.7 dB, and group C; 30.3 dB. This increase is most likely due to progressive labyrinthine otosclerosis. Group C in the average air-bone gap was greater (37.5 dB) than that in the patients with demineralization, group B1 (21.6 dB), group B2 (28.2 dB), group B3 (26.7 dB), the Carhart effect of group C was smaller than that of any other groups, thus suggesting the mode of otosclerosis progression in group C to be different from that in patients with demineralization. The results of the present study indicate that the preoperative CT findings of otosclerosis correlate with the audiometry findings, thus proving the usefulness of CT in diagnosing otosclerosis. (author)

  19. Pure tone audiometry and impedance screening of school entrant children by nurses: evaluation in a practical setting.


    Holtby, I; Forster, D P; Kumar, U.


    BACKGROUND: Screening for hearing loss in English children at entry to school (age 5-6 years) is usually by pure tone audiometry sweep undertaken by school nurses. This study aimed to compare the validity and screening rates of pure tone audiometry with impedance screening in these children. METHODS: Two stage pure tone audiometry and impedance methods of screening were compared in 610 school entry children from 19 infant schools in north east England. Both procedures were completed by school...

  20. Relations between perceptual measures of temporal processing, auditory-evoked brainstem responses and speech intelligibility in noise

    DEFF Research Database (Denmark)

    Papakonstantinou, Alexandra; Strelcyk, Olaf; Dau, Torsten


    for the chirp-evoked ABRs indicated a relation to SRTs and the ability to process temporal fine structure. Overall, the results demonstrate the importance of low-frequency temporal processing for speech reception which can be affected even if pure-tone sensitivity is close to normal....

  1. Brain responses evoked by high-frequency repetitive transcranial magnetic stimulation: an event-related potential study

    NARCIS (Netherlands)

    M. Hamidi; H.A. Slagter; G. Tononi; B.R. Postle


    Background Many recent studies have used repetitive transcranial magnetic stimulation (rTMS) to study brain-behavior relationships. However, the pulse-to-pulse neural effects of rapid delivery of multiple TMS pulses are unknown largely because of TMS-evoked electrical artifacts limiting recording of

  2. Time Course Analysis of the Effects of Botulinum Neurotoxin Type A on Pain and Vasomotor Responses Evoked by Glutamate Injection into Human Temporalis Muscles

    Directory of Open Access Journals (Sweden)

    Larissa Bittencourt da Silva


    Full Text Available The effect of botulinum neurotoxin type A (BoNTA on glutamate-evoked temporalis muscle pain and vasomotor responses was investigated in healthy men and women over a 60 day time course. Subjects participated in a pre-BoNTA session where their responses to injection of glutamate (1 M, 0.2 mL and saline (0.2 mL into the temporalis muscles were assessed. On Day 1, BoNTA (5 U was injected into one temporalis muscle and saline into the contralateral temporalis muscle, in a randomized order. Subjects then received intramuscular injections of glutamate (1 M, 0.2 mL into the left and right temporalis muscles at 3 h and subsequently 7, 30 and 60 days post-injection of BoNTA. Pain intensity, pain area, and neurogenic inflammation (skin temperature and skin blood perfusion were recorded. Prior to BoNTA treatment, glutamate evoked significantly greater pain and vasomotor reactions (P < 0.001 than saline. BoNTA significantly reduced glutamate-evoked pain intensity (P < 0.05, pain area (P < 0.01, skin blood perfusion (P < 0.05, and skin temperature (P < 0.001. The inhibitory effect of BoNTA was present at 3 h after injection, peaked after 7 days and returned to baseline by 60 days. Findings from the present study demonstrated a rapid action of BoNTA on glutamate-evoked pain and neurogenic inflammation, which is in line with animal studies.


    Directory of Open Access Journals (Sweden)

    Ch. Venkatasubbaiah


    Full Text Available BACKGROUND Despite the evidence that the incidence of hearing impairment is higher in type 2 diabetes subjects, very little is known about the nature and characteristics of this disability and the specific mechanisms leading to the hearing problems in diabetic adults. MATERIALS AND METHODS 40 patients with Type 2 Diabetes Mellitus were included in the study and grouped as patients aged 35 to 58 years (A and aged above 58 years (B; 40 patients were taken as control group with similar age grouping; 35 to 58 years (C above 58 years (D. Pure Tone Audiometry (PTA test was conducted according to the ASHA guidelines. Objective hearing evaluation was done by BERA (Brainstem Evoked Response Audiometry. RESULTS Higher degree of Hearing Loss (HL was observed in DM patients in all frequencies from 500 HZ to 10 KHZ in comparison to nonDM patients and it was statistically significant. Slower rate peaks occurred at I, III and V waves in elderly DM patients when compared to the elderly control group. (Peak I and V (p <0.001. Similarly, in the middle-aged group peaks I, III and V occurred at a significantly slower rate in the DM group when compared to the non-DM group (p <0.001. Interpeak latencies at 21.1 rate for peak III-V and peak I-V were consistently longer among the diabetics groups of two age groups when compared to the control group (p <0.001. Similar results were obtained at 63.3 rates in the elderly and middle-aged group. CONCLUSION In the earlier course of Type 2 Diabetes, though the person may be asymptomatic degenerative changes may begin to appear in the central auditory pathway and result in significant HL, which could be detected with early investigation to elicit of Brain Stem evoked potentials.

  4. Comparison of threshold estimation in infants with hearing loss or normal hearing using auditory steady-state response evoked by narrow band CE-chirps and auditory brainstem response evoked by tone pips

    DEFF Research Database (Denmark)

    Michel, Franck; Jørgensen, Kristoffer Foldager


    OBJECTIVE: The objective of this study is to compare air-conduction thresholds obtained with ASSR evoked by narrow band (NB) CE-chirps and ABR evoked by tone pips (tpABR) in infants with various degrees of hearing loss. DESIGN: Thresholds were measured at 500, 1000, 2000 and 4000 Hz. Data on each...... participant were collected at the same day. STUDY SAMPLE: Sixty-seven infants aged 4 d to 22 months (median age = 96 days), resulting in 57, 52, 87 and 56 ears for 500, 1000, 2000 and 4000 Hz, respectively. RESULTS: Statistical analysis was performed for ears with hearing loss (HL) and showed a very strong.......7). Linear regression analysis indicated that the relationship was not influenced by the degree of hearing loss. CONCLUSION: We propose that dB nHL to dB eHL correction values for ASSR evoked by NB CE-chirps should be 5 dB lower than values used for tpABR....

  5. Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients With Conductive and Sensorineural Hearing Loss and a Group With Vestibular Schawannoma

    Directory of Open Access Journals (Sweden)

    Parvane Mahdi


    Full Text Available Introduction: Vestibular evoked myogenic potential (VEMP has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients.   Materials and Methods: We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants.   Results: In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05. However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025. In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87% of the 32 ears using the AC method, whereas all (100% displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS, 2 (50.00% had neither AC-VEMP nor BC-VEMP. Conclusion:  Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

  6. Evoked Potentials and Human Intelligence. (United States)

    Ertl, John P.; Schafer, Edward W. P.

    Evidence of a relationship between the electrical responses of the human brain and psychometric measure of intelligence is presented. These involuntary cortical responses, known as average evoked potentials are considered to be the electrical signs of information processing by the brain. The time delays of these responses from presentation of a…

  7. The catalytic A1 domains of cholera toxin and heat-labile enterotoxin are potent DNA adjuvants that evoke mixed Th1/Th17 cellular immune responses. (United States)

    Bagley, Kenneth; Xu, Rong; Ota-Setlik, Ayuko; Egan, Michael; Schwartz, Jennifer; Fouts, Timothy


    DNA encoded adjuvants are well known for increasing the magnitude of cellular and/or humoral immune responses directed against vaccine antigens. DNA adjuvants can also tune immune responses directed against vaccine antigens to better protect against infection of the target organism. Two potent DNA adjuvants that have unique abilities to tune immune responses are the catalytic A1 domains of Cholera Toxin (CTA1) and Heat-Labile Enterotoxin (LTA1). Here, we have characterized the adjuvant activities of CTA1 and LTA1 using HIV and SIV genes as model antigens. Both of these adjuvants enhanced the magnitude of antigen-specific cellular immune responses on par with those induced by the well-characterized cytokine adjuvants IL-12 and GM-CSF. CTA1 and LTA1 preferentially enhanced cellular responses to the intracellular antigen SIVmac239-gag over those for the secreted HIVBaL-gp120 antigen. IL-12, GM-CSF and electroporation did the opposite suggesting differences in the mechanisms of actions of these diverse adjuvants. Combinations of CTA1 or LTA1 with IL-12 or GM-CSF generated additive and better balanced cellular responses to both of these antigens. Consistent with observations made with the holotoxin and the CTA1-DD adjuvant, CTA1 and LTA1 evoked mixed Th1/Th17 cellular immune responses. Together, these results show that CTA1 and LTA1 are potent DNA vaccine adjuvants that favor the intracellular antigen gag over the secreted antigen gp120 and evoke mixed Th1/Th17 responses against both of these antigens. The results also indicate that achieving a balanced immune response to multiple intracellular and extracellular antigens delivered via DNA vaccination may require combining adjuvants that have different and complementary mechanisms of action.

  8. The effect of intrathecal iohexol on visual evoked response latency: a comparison including incidence of headache with iopamidol and metrizamide in myeloradiculography. (United States)

    Broadbridge, A T; Bayliss, S G; Brayshaw, C I


    Fifty consecutive unselected patients referred for myeloradiculography and examined by the same radiologist, when facilities for measuring the visual evoked response were available, are considered. The effect on the visual evoked response of the examination and the incidence of headache following the use of iohexol as the contrast medium are compared with those after the use of iopamidol and metrizamide reported in a previous study. A total of 400 cases examined with iopamidol and 200 cases examined with iohexol are reviewed with regard to the incidence of headache. Whereas iopamidol and, to a greater extent metrizamide, were found to cause significant lengthening of the visual evoked response latency 20 hours after the radiological examination, iohexol did not. Furthermore there was no significant difference in the 20 hour reading following the use of iohexol compared with the original control group of patients who underwent lumbar puncture alone. There was a lower incidence and severity of headache following the use of iohexol than with iopamidol and a markedly reduced incidence compared with metrizamide. Iohexol is considered less neurotoxic than iopamidol which had previously superceded metrizamide as the contrast medium used for myeloradiculography in the Royal Surrey County Hospital. Volumes of up to 14 ml of iohexol 300 mg I/ml have been used for lumbar radiculography and for total myelography and up to 10 ml for direct lateral cervical puncture. In 350 cases examined to date with iohexol the only serious sequel was a case of chemical meningitis following the lumbar injection of 10 ml of the 300 mg I/ml solution for a cervical examination. The patient made an uneventful recovery.

  9. Electrically-Evoked Frequency-Following Response(EFFR) of Guinea Pigs%豚鼠电刺激频率跟随反应初步研究

    Institute of Scientific and Technical Information of China (English)

    丁秀勇; 何文欣; 张汝祥; 陈婧


    目的:探索豚鼠听觉系统对电刺激信号是否存在频率跟随现象。方法经圆窗龛使用纯音和白噪音电信号对豚鼠耳蜗行电刺激,记录其头皮电反应,经Matlab信号叠加和伪迹去除,计算EFFR信号相对幅度、输入输出函数,处死豚鼠和使用电阻代替豚鼠后记录EFFR变化验证EFFR来源。结果纯音电信号可诱发具有明显的周期性的EFFR信号,在797Hz和1597Hz所记录EFFR到的相对幅度(RA)均值明显高于白噪音RA均值(P<0.05);797Hz纯音电信号输出幅度随着刺激电刺激幅度增长呈非线性改变,呈现神经反应特有的阈值特性与饱和特性;豚鼠死亡前后EFFR的RA值差异具有高度显著性(P<0.001),豚鼠EFFR的RA值与使用电阻记录的RA值差异具有显著性(P<0.05)。结论听力正常豚鼠听觉系统对电刺激信号存在频率跟随现象。%Objective To explore the Electrically-Evoked Frequency-Following Response whether exist in guinea pig auditory system. Methods Periodic signals and white noise electrical stimuli were used for guinea pigs cochlear electrical stimulation, The EFFR were recorded in the guinea pigs scalp and analyzed, the EFFR also verified by recording of death guinea pigs and electrical resistance. Results EFFR evoked by periodic signals were significantly higher than those evoked by the white noise;the responses decreased significantly after death of the guineapigs; and the responses decreased significantly when the animal was replaced by an electrical resistance. Conclusions Electrically-Evoked Frequency-Following Response can be recorded in the guinea pigs with normal hearing.

  10. [Auditory-evoked responses to a monaural or a binaural click, recorded from the vertex, as in two temporal derivations; effect of interaural time differences (author's transl)]. (United States)

    Botte, M C; Chocholle, R


    The auditory-evoked responses have been recorded on 5 subject by vertex, right temporal and left temporal electrodes simultaneously. 30 dB sensation level clicks were used as stimuli; one click was presented only to the right ear, or one click only to the left ear, or one click to the right ear and another click to the left ear with a variable interaural time difference in this latter case (0-150 ms). The N-P amplitude variations and the N and P latency variations have been studied and compared to those observed in the perceived lateralizations of the sound source.

  11. Inflammation-mediating cytokine response to acute handcycling exercise with/without functional electrical stimulation-evoked lower-limb cycling

    Directory of Open Access Journals (Sweden)

    Thomas A. W. Paulson, MSc


    Full Text Available This feasibility study compared the plasma inflammation-mediating cytokine response to an acute bout of handcycling (HC with and without the addition of functional electrical stimulation (FES-evoked lower-limb cycling. On two separate occasions, five recreationally active, community-based participants with motor complete paraplegia (thoracic 5–7 performed 30 min HC and hybrid exercise (HYB at a fixed power output. Venous blood samples were collected at rest, immediately postexercise, 1 h postexercise (post+1 and 2 h postexercise (post+2. Plasma interleukin (IL-6, IL-10, IL-1 receptor antagonist (IL-1ra, adrenaline, and cortisol concentrations were determined via enzyme-linked immunoassay. Plasma IL-6 concentrations were significantly (p 0.05 increase in IL-6 was observed at post+1 in HC, with concentrations significantly higher in HYB at post+2 (p < 0.02. Plasma IL-1ra was unaffected in both trials. Although not reaching statistical significance (p = 0.15, a ~1-fold increase in IL-10 concentration was seen in HYB at post+2. In contrast, increases in adrenaline (p < 0.04 and cortisol (p = 0.08 were observed immediately postexercise in HC and HYB. Initial findings suggest paralyzed skeletal muscle releases IL-6 in response to FES-evoked contractions. HYB may provide a greater anti-inflammatory potential in individuals with a thoracic spinal cord injury compared with HC alone.


    Directory of Open Access Journals (Sweden)

    Siddharth Nirwan


    Full Text Available BACKGROUND : Chronic S uppurative O titis M edia (CSOM is an important cause of preventable hearing loss , particularly in the developing world. Tympanoplasty is a procedure to eradicate the disease in middle ear and to reconstruct hearing mechanism. Pure tone audiometry is an efficient , simple and economic tool to assess the level of postoperative hearing gain

  13. Air-Puff Conditioning Audiometry: Extending Its Applicability with Multiply Handicapped Individuals. (United States)

    Lancioni, G. E.; And Others


    This study examined the use of air-puff conditioning audiometry in the hearing assessment of 12 multiply handicapped (including severe/profound mental retardation) subjects, ages 9-32. Ten subjects reached criterion conditioning and then completed the hearing assessment with the air-puff procedure while one reached criterion with a modified…

  14. Serial audiometry and speech recognition findings in Finnish Usher syndrome type III patients.

    NARCIS (Netherlands)

    Plantinga, R.F.; Kleemola, L.; Huygen, P.L.M.; Joensuu, T.; Sankila, E.M.; Pennings, R.J.E.; Cremers, C.W.R.J.


    Audiometric features, evaluated by serial pure tone audiometry and speech recognition tests (n = 31), were analysed in 59 Finnish Usher syndrome type III patients (USH3) with Finmajor/Finmajor (n = 55) and Finmajor/Finminor (n = 4) USH3A mutations. These patients showed a highly variable type and de

  15. Infant Thresholds with Enhanced Attention to the Signal in Visual Reinforcement Audiometry. (United States)

    Primus, Michael A.


    A standard operant procedure, Visual Reinforcement Audiometry, was modified to enhance 16 infants' attention to impending auditory signals. The modified technique achieved an average 5.5 dB improvement in threshold over the conventional technique. Correction for adult performance in similar tasks indicated a 3.3 dB attentional effect between…

  16. Audiometry for the Retarded: With Implications for the Difficult-to-Test. (United States)

    Fulton, Robert T., Ed.; And Others

    Directed to professionals with a basic knowledge of audiological principles, the text presents a review of audiological assessment procedures and their applicability to the retarded. Pure-tone, speech, and Bekesy audiometry are described. Also discussed are differential diagnosis of auditory impairments, conditioning and audiological assessment,…

  17. Vasopressin V1 receptors contribute to hemodynamic and sympathoinhibitory responses evoked by stimulation of adenosine A2a receptors in NTS. (United States)

    Scislo, Tadeusz J; O'Leary, Donal S


    Activation of adenosine A2a receptors in the nucleus of the solitary tract (NTS) decreases mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA), whereas increases in preganglionic adrenal sympathetic nerve activity (pre-ASNA) occur, a pattern similar to that observed during hypotensive hemorrhage. Central vasopressin V1 receptors may contribute to posthemorrhagic hypotension and bradycardia. Both V1 and A2a receptors are densely expressed in the NTS, and both of these receptors are involved in cardiovascular control; thus they may interact. The responses elicited by NTS A2a receptors are mediated mostly via nonglutamatergic mechanisms, possibly via release of vasopressin. Therefore, we investigated whether blockade of NTS V1 receptors alters the autonomic response patterns evoked by stimulation of NTS A2a receptors (CGS-21680, 20 pmol/50 nl) in alpha-chloralose-urethane anesthetized male Sprague-Dawley rats. In addition, we compared the regional sympathetic responses to microinjections of vasopressin (0.1-100 ng/50 nl) into the NTS. Blockade of V1 receptors reversed the normal decreases in MAP into increases (-95.6 +/- 28.3 vs. 51.4 +/- 15.7 integralDelta%), virtually abolished the decreases in HR (-258.3 +/- 54.0 vs. 18.9 +/- 57.8 integralDeltabeats/min) and RSNA (-239.3 +/- 47.4 vs. 15.9 +/- 36.1 integralDelta%), and did not affect the increases in pre-ASNA (279.7 +/- 48.3 vs. 233.1 +/- 54.1 integralDelta%) evoked by A2a receptor stimulation. The responses partially returned toward normal values approximately 90 min after the blockade. Microinjections of vasopressin into the NTS evoked dose-dependent decreases in HR and RSNA and variable MAP and pre-ASNA responses with a tendency toward increases. We conclude that the decreases in MAP, HR, and RSNA in response to NTS A2a receptor stimulation may be mediated via release of vasopressin from neural terminals in the NTS. The differential effects of NTS V1 and A2a receptors on

  18. Validity of diagnostic computer-based air and forehead bone conduction audiometry. (United States)

    Swanepoel, De Wet; Biagio, Leigh


    Computer-based audiometry allows for novel applications, including remote testing and automation, that may improve the accessibility and efficiency of hearing assessment in various clinical and occupational health settings. This study describes the validity of computer-based, diagnostic air and forehead bone conduction audiometry when compared wtih conventional industry standard audiometry in a sound booth environment. A sample of 30 subjects (19 to 77 years of age) was assessed with computer-based (KUDUwave 5000) and industry standard conventional audiometers (GSI 61) to compare air and bone conduction thresholds and test-retest reliability. Air conduction thresholds for the two audiometers corresponded within 5 dB or less in more than 90% of instances, with an average absolute difference of 3.5 dB (3.8 SD) and a 95% confidence interval of 2.6 to 4.5 dB. Bone conduction thresholds for the two audiometers corresponded within 10 dB or less in 92% of instances, with an average absolute difference of 4.9 dB (4.9 SD) and a 95% confidence interval of 3.6 to 6.1 dB. The average absolute test-retest threshold difference for bone conduction on the industry standard audiometer was 5.1 dB (5.3 SD) and for the computer-based audiometer 7.1 dB (6.4 SD). Computer-based audiometry provided air and bone conduction thresholds within the test-retest reliability limits of industry standard audiometry.

  19. Auditory- and Vestibular-Evoked Potentials Correlate with Motor and Non-Motor Features of Parkinson’s Disease (United States)

    Shalash, Ali Soliman; Hassan, Dalia Mohamed; Elrassas, Hanan Hani; Salama, Mohamed Mosaad; Méndez-Hernández, Edna; Salas-Pacheco, José M.; Arias-Carrión, Oscar


    Degeneration of several brainstem nuclei has been long related to motor and non-motor symptoms (NMSs) of Parkinson’s disease (PD). Nevertheless, due to technical issues, there are only a few studies that correlate that association. Brainstem auditory-evoked potential (BAEP) and vestibular-evoked myogenic potential (VEMP) responses represent a valuable tool for brainstem assessment. Here, we investigated the abnormalities of BAEPs, ocular VEMPs (oVEMPs), and cervical VEMPs (cVEMPs) in patients with PD and its correlation to the motor and NMSs. Fifteen patients diagnosed as idiopathic PD were evaluated by Unified Parkinson’s Disease Rating Scale and its subscores, Hoehn and Yahr scale, Schwab and England scale, and Non-Motor Symptoms Scale. PD patients underwent pure-tone, speech audiometry, tympanometry, BAEP, oVEMPs, and cVEMPs, and compared to 15 age-matched control subjects. PD subjects showed abnormal BAEP wave morphology, prolonged absolute latencies of wave V and I–V interpeak latencies. Absent responses were the marked abnormality seen in oVEMP. Prolonged latencies with reduced amplitudes were seen in cVEMP responses. Rigidity and bradykinesia were correlated to the BAEP and cVEMP responses contralateral to the clinically more affected side. Contralateral and ipsilateral cVEMPs were significantly correlated to sleep (p = 0.03 and 0.001), perception (p = 0.03), memory/cognition (p = 0.025), and urinary scores (p = 0.03). The oVEMP responses showed significant correlations to cardiovascular (p = 0.01) and sexual dysfunctions (p = 0.013). PD is associated with BAEP and VEMP abnormalities that are correlated to the motor and some non-motor clinical characteristics. These abnormalities could be considered as potential electrophysiological biomarkers for brainstem dysfunction and its associated motor and non-motor features. PMID:28289399

  20. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Directory of Open Access Journals (Sweden)

    Baird Bill


    Full Text Available Abstract Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves. Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1 Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2 These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3 The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide

  1. Gating of the vertex somatosensory and auditory evoked potential P50 and the correlation to skin conductance orienting response in healthy men. (United States)

    Arnfred, S M; Eder, D N; Hemmingsen, R P; Glenthøj, B Y; Chen, A C


    A defect in auditory evoked potential (AEP) P50 gating supports the theory of information-processing deficits in schizophrenia. The relationship between gating of the mid-latency evoked potentials (EP) in the somatosensory and the auditory modalities has not been studied together before. In schizophrenia, we might expect the processing deficits to act on multiple modalities. We have examined the gating of median nerve somatosensory EP (SEP) following paired stimulation identical to the AEP P50 gating paradigm using interstimulus intervals (ISI) of 500, 750 and 1000 ms and the correlation of gating to the skin conductance orienting response (SCOR) in 20 healthy men. We measured mid-latency vertex components (SEP: P50, N65, P85 and N100; AEP: P30, N45, P50 and N80). The gating was most pronounced at ISI 500 ms where the SEP P50 and N100 gating were 0.59 and 0.37, respectively, as compared to a gating of 0.61 in P30, 0.33 in P50 and 0.45 in N80 in the AEP. Repetition effects in the two modalities were not correlated. AEP P50 gating was correlated to skin conductance level (SCL). The combination of recording repetition effects on the mid-latency EP in two modalities could provide a method for investigating if deficits of information processing in schizophrenia are cross-modal.


    This manuscript characterizes the receptor pathways involved in pattern-evoked potential generation in rats" NMDA and nicotinic acetylcholine receptors appear to be involved in the generation of the steady-state pattern evoked response in vivo." The pattern evok...

  3. The role of calcium, calcium-activated K+ channels, and tyrosine/kinase in psoralen-evoked responses in human melanoma cells

    Directory of Open Access Journals (Sweden)

    Isoldi M.C.


    Full Text Available 8-Methoxy psoralen (8-MOP exerts a short-term (24 h mitogenic action, and a long-term (48-72 h anti-proliferative and melanogenic action on two human melanoma cell lines, SK-Mel 28 and C32TG. An increase of intracellular calcium concentration was observed by spectrofluorometry immediately after the addition of 0.1 mM 8-MOP to both cell lines, previously incubated with calcium probe fluo-3 AM (5 µM. The intracellular Ca2+ chelator BAPTA/AM (1 µM blocked both early (mitogenic and late (anti-proliferative and melanogenic 8-MOP effects on both cell lines, thus revealing the importance of the calcium signal in both short- and long-term 8-MOP-evoked responses. Long-term biological assays with 5 and 10 mM tetraethylammonium chloride (TEA, an inhibitor of Ca2+-dependent K+ channels did not affect the responses to psoralen; however, in 24-h assays 10 mM TEA blocked the proliferative peak, indicating a modulation of Ca2+-dependent K+ channels by 8-MOP. No alteration of cAMP basal levels or forskolin-stimulated cAMP levels was promoted by 8-MOP in SK-Mel 28 cells, as determined by radioimmunoassay. However, in C32TG cells forskolin-stimulated cAMP levels were further increased in the presence of 8-MOP. In addition, assays with 1 µM protein kinase C and calcium/calmodulin-dependent kinase inhibitors, Ro 31-8220 and KN-93, respectively, excluded the participation of these kinases in the responses evoked by 8-MOP. Western blot with antibodies anti-phosphotyrosine indicated a 92% increase of the phosphorylated state of a 43-kDa band, suggesting that the phosphorylation of this protein is a component of the cascade that leads to the increase of tyrosinase activity.

  4. Sensitive Period for the Recovery of the Response Rate of the Wind-Evoked Escape Behavior of Unilaterally Cercus-Ablated Crickets (Gryllus bimaculatus). (United States)

    Takuwa, Hiroyuki; Kanou, Masamichi


    We examined the compensational recovery of the response rate (relative occurrence) of the wind-evoked escape behavior in unilaterally cercus-ablated crickets (Gryllus bimaculatus) and elucidated the existence of a sensitive period for such recovery by rearing the crickets under different conditions. In one experiment, each cricket was reared in an apparatus called a walking inducer (WI) to increase the sensory input to the remaining cercus, i.e., the self-generated wind caused by walking. In another experiment, each cricket was reared in a small plastic case separate from the outside atmosphere (wind-free: WF). In this rearing condition, the cricket did not experience self-generated wind as walking was prohibited. During the recovery period after the unilateral cercus ablation, the crickets were reared under either the WI or WF condition to investigate the role of the sensory inputs on the compensational recovery of the response rate. The compensational recovery of the response rate occurred only in the crickets reared under the WI condition during the early period after the ablation. In particular, WI rearing during the first three days after the ablation resulted in the largest compensational recovery in the response rate. In contrast, no compensational recovery was observed in the crickets reared under the WF condition during the first three days. These results suggest that a sensitive period exists in which sensory inputs from the remaining cercus affect the compensational recovery of the response rate more effectively than during other periods.

  5. Age-Related Differences in Response to Music-Evoked Emotion among Children and Adolescents with Autism Spectrum Disorders (United States)

    Stephenson, K. G.; Quintin, E. M.; South, M.


    While research regarding emotion recognition in ASD has focused primarily on social cues, musical stimuli also elicit strong emotional responses. This study extends and expands the few previous studies of response to music in ASD, measuring both psychophysiological and behavioral responses in younger children (ages 8-11) as well as older…

  6. Gating of the vertex somatosensory and auditory evoked potential P50 and the correlation to skin conductance orienting response in healthy men

    DEFF Research Database (Denmark)

    Arnfred, S M; Eder, D N; Hemmingsen, R P;


    A defect in auditory evoked potential (AEP) P50 gating supports the theory of information-processing deficits in schizophrenia. The relationship between gating of the mid-latency evoked potentials (EP) in the somatosensory and the auditory modalities has not been studied together before. In schiz......A defect in auditory evoked potential (AEP) P50 gating supports the theory of information-processing deficits in schizophrenia. The relationship between gating of the mid-latency evoked potentials (EP) in the somatosensory and the auditory modalities has not been studied together before...

  7. Relationship between the findings of pure-tone audiometry and otoacoustic emission tests on military police personnel


    Guida, Heraldo Lorena; De Sousa, Ariane Laís [UNESP; Cardoso,Ana Cláudia Vieira


    Introduction: Otoacoustic emissions can be an alternative for cochlear evaluation in noise induced hearing loss (NIHL). Objective: To investigate the correlation between the findings of audiometry results and distortion product otoacoustic emissions (DPOAE) in the military police. Method: from cross-sectional and retrospective study, 200 military police officers were submitted to audiological evaluation - pure tone audiometry and DPOAE. Results: considering the provisions of Ordinance 19 of t...

  8. Rapid stimulus-evoked astrocyte Ca2+ elevations and hemodynamic responses in mouse somatosensory cortex in vivo

    DEFF Research Database (Denmark)

    Lind, Barbara Lykke; Brazhe, Alexey; Jessen, Sanne Barsballe;


    in astrocyte somas, processes, and end-feet preceded local vasodilatation. Fast Ca(2+) responses in both neurons and astrocytes correlated with synaptic activity, but only the astrocytic responses correlated with the hemodynamic shifts. These data establish that a large proportion of cortical astrocytes have...

  9. Development of the Complex General Linear Model in the Fourier Domain: Application to fMRI Multiple Input-Output Evoked Responses for Single Subjects

    Directory of Open Access Journals (Sweden)

    Daniel E. Rio


    Full Text Available A linear time-invariant model based on statistical time series analysis in the Fourier domain for single subjects is further developed and applied to functional MRI (fMRI blood-oxygen level-dependent (BOLD multivariate data. This methodology was originally developed to analyze multiple stimulus input evoked response BOLD data. However, to analyze clinical data generated using a repeated measures experimental design, the model has been extended to handle multivariate time series data and demonstrated on control and alcoholic subjects taken from data previously analyzed in the temporal domain. Analysis of BOLD data is typically carried out in the time domain where the data has a high temporal correlation. These analyses generally employ parametric models of the hemodynamic response function (HRF where prewhitening of the data is attempted using autoregressive (AR models for the noise. However, this data can be analyzed in the Fourier domain. Here, assumptions made on the noise structure are less restrictive, and hypothesis tests can be constructed based on voxel-specific nonparametric estimates of the hemodynamic transfer function (HRF in the Fourier domain. This is especially important for experimental designs involving multiple states (either stimulus or drug induced that may alter the form of the response function.

  10. The Nicotine-Evoked Locomotor Response: A Behavioral Paradigm for Toxicity Screening in Zebrafish (Danio rerio Embryos and Eleutheroembryos Exposed to Methylmercury.

    Directory of Open Access Journals (Sweden)

    Francisco X Mora-Zamorano

    Full Text Available This study is an adaptation of the nicotine-evoked locomotor response (NLR assay, which was originally utilized for phenotype-based neurotoxicity screening in zebrafish embryos. Zebrafish embryos do not exhibit spontaneous swimming until roughly 4 days post-fertilization (dpf, however, a robust swimming response can be induced as early as 36 hours post-fertilization (hpf by means of acute nicotine exposure (30-240μM. Here, the NLR was tested as a tool for early detection of locomotor phenotypes in 36, 48 and 72 hpf mutant zebrafish embryos of the non-touch-responsive maco strain; this assay successfully discriminated mutant embryos from their non-mutant siblings. Then, methylmercury (MeHg was used as a proof-of-concept neurotoxicant to test the effectiveness of the NLR assay as a screening tool in toxicology. The locomotor effects of MeHg were evaluated in 6 dpf wild type eleutheroembryos exposed to waterborne MeHg (0, 0.01, 0.03 and 0.1μM. Afterwards, the NLR assay was tested in 48 hpf embryos subjected to the same MeHg exposure regimes. Embryos exposed to 0.01 and 0.03μM of MeHg exhibited significant increases in locomotion in both scenarios. These findings suggest that similar locomotor phenotypes observed in free swimming fish can be detected as early as 48 hpf, when locomotion is induced with nicotine.

  11. Monsoonal variability in abiotic parameters in coastal waters off Trivandrum evokes press and pulse response in biotic variables

    Digital Repository Service at National Institute of Oceanography (India)

    Subina, N.S.; Bhosle, S.; Nair, S.; Lokabharathi, P.A.

    Trivandrum Coast experiences coastal upwelling during south west monsoon, which is accompanied by abiotic changes in physio-chemical parameters. The resultant biotic responses could range from an instantaneous pulse to a sustained press reaction...

  12. Brainstem auditory evoked potentials in children with lead exposure

    Directory of Open Access Journals (Sweden)

    Katia de Freitas Alvarenga


    Full Text Available Introduction: Earlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. Objective: To investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. Methods: Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months ± 3 years, 2 months. Results: The mean time-integrated cumulative blood lead index was 12 µg/dL (SD ± 5.7, range:2.433. All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I-III, III-V, and I-V, and the cumulative lead values. Conclusion: No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.

  13. Dynamic movement of N100m current sources in auditory evoked fields: comparison of ipsilateral versus contralateral responses in human auditory cortex. (United States)

    Jin, Chun Yu; Ozaki, Isamu; Suzuki, Yasumi; Baba, Masayuki; Hashimoto, Isao


    We recorded auditory evoked magnetic fields (AEFs) to monaural 400Hz tone bursts and investigated spatio-temporal features of the N100m current sources in the both hemispheres during the time before the N100m reaches at the peak strength and 5ms after the peak. A hemispheric asymmetry was evaluated as the asymmetry index based on the ratio of N100m peak dipole strength between right and left hemispheres for either ear stimulation. The results of asymmetry indices showed right-hemispheric dominance for left ear stimulation but no hemispheric dominance for right ear stimulation. The current sources for N100m in both hemispheres in response to monaural 400Hz stimulation moved toward anterolateral direction along the long axis of the Heschl gyri during the time before it reaches the peak strength; the ipsilateral N100m sources were located slightly posterior to the contralateral N100m ones. The onset and peak latencies of the right hemispheric N100m in response to right ear stimulation are shorter than those of the left hemispheric N100m to left ear stimulation. The traveling distance of the right hemispheric N100m sources following right ear stimulation was longer than that for the left hemispheric ones following left ear stimulation. These results suggest the right-dominant hemispheric asymmetry in pure tone processing.

  14. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;


    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...

  15. Acupuncture-Evoked Response in Somatosensory and Prefrontal Cortices Predicts Immediate Pain Reduction in Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Yumi Maeda


    Full Text Available The linkage between brain response to acupuncture and subsequent analgesia remains poorly understood. Our aim was to evaluate this linkage in chronic pain patients with carpal tunnel syndrome (CTS. Brain response to electroacupuncture (EA was evaluated with functional MRI. Subjects were randomized to 3 groups: (1 EA applied at local acupoints on the affected wrist (PC-7 to TW-5, (2 EA at distal acupoints (contralateral ankle, SP-6 to LV-4, and (3 sham EA at nonacupoint locations on the affected wrist. Symptom ratings were evaluated prior to and following the scan. Subjects in the local and distal groups reported reduced pain. Verum EA produced greater reduction of paresthesia compared to sham. Compared to sham EA, local EA produced greater activation in insula and S2 and greater deactivation in ipsilateral S1, while distal EA produced greater activation in S2 and deactivation in posterior cingulate cortex. Brain response to distal EA in prefrontal cortex (PFC and brain response to verum EA in S1, SMA, and PFC were correlated with pain reduction following stimulation. Thus, while greater activation to verum acupuncture in these regions may predict subsequent analgesia, PFC activation may specifically mediate reduced pain when stimulating distal acupoints.

  16. Interferon (IFN) and Cellular Immune Response Evoked in RNA-Pattern Sensing During Infection with Hepatitis C Virus (HCV). (United States)

    Nakai, Masato; Oshiumi, Hiroyuki; Funami, Kenji; Okamoto, Masaaki; Matsumoto, Misako; Seya, Tsukasa; Sakamoto, Naoya


    Hepatitis C virus (HCV) infects hepatocytes but not dendritic cells (DCs), but DCs effectively mature in response to HCV-infected hepatocytes. Using gene-disrupted mice and hydrodynamic injection strategy, we found the MAVS pathway to be crucial for induction of type III interferons (IFNs) in response to HCV in mouse. Human hepatocytes barely express TLR3 under non-infectious states, but frequently express it in HCV infection. Type I and III IFNs are induced upon stimulation with polyI:C, an analog of double-stranded (ds)RNA. Activation of TLR3 and the TICAM-1 pathway, followed by DC-mediated activation of cellular immunity, is augmented during exposure to viral RNA. Although type III IFNs are released from replication-competent human hepatocytes, DC-mediated CTL proliferation and NK cell activation hardly occur in response to the released type III IFNs. Yet, type I IFNs and HCV-infected hepatocytes can induce maturation of DCs in either human or mouse origin. In addition, mouse CD8+ DCs mature in response to HCV-infected hepatocytes unless the TLR3/TICAM-1 pathway is blocked. We found the exosomes containing HCV RNA in the supernatant of the HCV-infected hepatocytes act as a source of TLR3-mediated DC maturation. Here we summarize our view on the mechanism by which DCs mature to induce NK and CTL in a status of HCV infection.

  17. Does Chronic Tinnitus Alter the Emotional Response Function of the Amygdala?: A Sound-Evoked fMRI Study (United States)

    Davies, Jeff E.; Gander, Phillip E.; Hall, Deborah A.


    Tinnitus is often associated with strong negative thoughts and emotions which can contribute to a distressing and chronic long-term condition. The amygdala, the “feeling and reacting” part of the brain, may play a key role in this process. Although implicated in several theoretical models of tinnitus, quantification of activity in the human amygdala has only been made possible more recently through neuroimaging methods such as functional magnetic resonance imaging (fMRI) but benefits from modified scanning parameters using a double-echo acquisition for improved BOLD sensitivity. This study thus examined the role of the amygdala in emotional sound processing in people with tinnitus using a novel double-echo imaging sequence for optimal detectability of subcortical activity. Our hypotheses were: (1) emotionally evocative sound clips rated as pleasant or unpleasant would elicit stronger amygdalar activation than sound clips rated as neutral, (2) people with tinnitus have greater amygdalar activation in response to emotionally evocative sounds (relative to neutral sounds) compared to controls. Methods: Twelve participants all with chronic, constant tinnitus took part. We also recruited 11 age and hearing-matched controls. Participants listened to a range of emotionally evocative sound clips; rated as pleasant, unpleasant or neutral. A region-of-interest analysis was chosen to test our a priori hypotheses. Results: Both groups displayed a robust and similar overall response to sounds vs. silence in the following ascending auditory pathways; inferior colliculus, medial geniculate body and the primary auditory cortex. In support of our first hypothesis, the amygdala's response to pleasant and unpleasant sound clips was significantly greater than neutral sounds. Opposing our second hypothesis, we found that the amygdala's overall response to pleasant and unpleasant sounds (compared to neutral sounds) was actually lower in the tinnitus group as compared to the controls

  18. Recording of electrically evoked auditory brainstem responses (E-ABR) with an integrated stimulus generator in Matlab. (United States)

    Bahmer, Andreas; Peter, Otto; Baumann, Uwe


    Electrical auditory brainstem responses (E-ABRs) of subjects with cochlear implants are used for monitoring the physiologic responses of early signal processing of the auditory system. Additionally, E-ABR measurements allow the diagnosis of retro-cochlear diseases. Therefore, E-ABR should be available in every cochlear implant center as a diagnostic tool. In this paper, we introduce a low-cost setup designed to perform an E-ABR as well as a conventional ABR for research purposes. The distributable form was developed with Matlab and the Matlab Compiler (The Mathworks Inc.). For the ABR, only a PC with a soundcard, conventional system headphones, and an EEG pre-amplifier are necessary; for E-ABR, in addition, an interface to the cochlea implant is required. For our purposes, we implemented an interface for the Combi 40+/Pulsar implant (MED-EL, Innsbruck).

  19. Study of the central auditive pathway by encephalic trunk evoked e auditory responses (ear) in children with language retard


    Gallardo, Manuel; Servicio de Otorrinolaringología, Hospital Central de la Fuerza Aérea del Perú; Vera, Carlos; Servicio de Otorrinolaringología, Hospital Central de la Fuerza Aérea del Perú


    Objetive: To determine the functional integrity of the brainstem auditory pathway by the auditive brainstem response (ABR) in language-retarded children without pathology in both the middle ear and central nervous system and no neonatal hearing loss risk factors. Design: Retrospective transversal study. Setting: Naval Medical Center and Air Force Central Hospital Otorhinolaryngology Services, Lima. Peru. Material and methods: Analysis of children’s ABR performed in the last ten years included...

  20. Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)- and non-ESBL-producing uropathogenic E. coli



    Background Infections caused by extended spectrum beta-lactamases (ESBL)-producing bacteria have been emerging worldwide and the majority of ESBL-producing E. coli strains are isolated from patients with urinary tracts infections. The purpose of this study was to compare the host-response mechanisms in human polymorphonucleated leukocytes (PMN) and renal epithelial cells when stimulated by ESBL- or non-ESBL-producing uropathogenic E. coli (UPEC) isolates. The host-pathogen interaction of thes...

  1. Plasticity of the mate choice mind: courtship evokes choice-like brain responses in females from a coercive mating system. (United States)

    Wang, S M T; Ramsey, M E; Cummings, M E


    Female mate choice is fundamental to sexual selection, and determining molecular underpinnings of female preference variation is important for understanding mating character evolution. Previously it was shown that whole-brain expression of a synaptic plasticity marker, neuroserpin, positively correlates with mating bias in the female choice poeciliid, Xiphophorus nigrensis, when exposed to conspecific courting males, whereas this relationship is reversed in Gambusia affinis, a mate coercive poeciliid with no courting males. Here we explore whether species-level differences in female behavioral and brain molecular responses represent 'canalized' or 'plastic' traits. We expose female G. affinis to conspecific males and females, as well as coercive and courting male Poecilia latipinna, for preference assays followed by whole-brain gene expression analyses of neuroserpin, egr-1 and early B. We find positive correlations between gene expression and female preference strength during exposure to courting heterospecific males, but a reversed pattern following exposure to coercive heterospecific males. This suggests that the neuromolecular processes associated with female preference behavior are plastic and responsive to different male phenotypes (courting or coercive) rather than a canalized response linked to mating system. Further, we propose that female behavioral plasticity may involve learning because female association patterns shifted with experience. Compared to younger females, we found larger, more experienced females spend less time near coercive males but associate more with males in the presence of courters. We thus suggest a conserved learning-based neuromolecular process underlying the diversity of female mate preference across the mate choice and coercion-driven mating systems.

  2. Odour-evoked responses to queen pheromone components and to plant odours using optical imaging in the antennal lobe of the honey bee drone Apis mellifera L. (United States)

    Sandoz, Jean-Christophe


    The primordial functional role of honey bee males (drones) is to mate with virgin queens, a behaviour relying heavily on the olfactory detection of queen pheromone. In the present work I studied olfactory processing in the drone antennal lobe (AL), the primary olfactory centre of the insect brain. In drones, the AL consists of about 103 ordinary glomeruli and four enlarged glomeruli, the macroglomeruli (MG). Two macroglomeruli (MG1 and MG2) and approximately 20 ordinary glomeruli occupy the anterior surface of the antennal lobe and are thus accessible to optical recordings. Calcium imaging was used to measure odour-evoked responses to queen pheromonal components and plant odours. MG2 responded specifically to the main component of the queen mandibular pheromone, 9-ODA. The secondary components HOB and HVA each triggered activity in one, but not the same, ordinary glomerulus. MG1 did not respond to any of the tested stimuli. Plant odours induced signals only in ordinary glomeruli in a combinatorial manner, as in workers. This study thus shows that the major queen pheromonal component is processed in the most voluminous macroglomerulus of the drone antennal lobe, and that plant odours, as well as some queen pheromonal components, are processed in ordinary glomeruli.

  3. Brainstem auditory evoked response characteristics in normal-hearing subjects with chronic tinnitus and in non-tinnitus group

    Directory of Open Access Journals (Sweden)

    Shadman Nemati


    Full Text Available Background and Aim: While most of the people with tinnitus have some degrees of hearing impairment, a small percent of patients admitted to ear, nose and throat clinics or hearing evaluation centers are those who complain of tinnitus despite having normal hearing thresholds. This study was performed to better understanding of the reasons of probable causes of tinnitus and to investigate possible changes in the auditory brainstem function in normal-hearing patients with chronic tinnitus.Methods: In this comparative cross-sectional, descriptive and analytic study, 52 ears (26 with and 26 without tinnitus were examined. Components of the auditory brainstem response (ABR including wave latencies and wave amplitudes were determined in the two groups and analyzed using appropriate statistical methods.Results: The mean differences between the absolute latencies of waves I, III and V was less than 0.1 ms between the two groups that was not statistically significant. Also, the interpeak latency values of waves I-III, III-V and I-V in both groups had no significant difference. Only, the V/I amplitude ratio in the tinnitus group was significantly higher (p=0.04.Conclusion: The changes observed in amplitude of waves, especially in the latter ones, can be considered as an indication of plastic changes in neuronal activity and its possible role in generation of tinnitus in normal-hearing patients.

  4. Cannabinoid CB2 receptor activation inhibits mechanically evoked responses of wide dynamic range dorsal horn neurons in naïve rats and in rat models of inflammatory and neuropathic pain. (United States)

    Elmes, Steven J R; Jhaveri, Maulik D; Smart, Darren; Kendall, David A; Chapman, Victoria


    Peripheral cannabinoid 2 receptors (CB2 receptors) modulate immune responses and attenuate nociceptive behaviour in models of acute and persistent pain. The aim of the present study was to investigate whether peripheral CB2 receptors modulate spinal processing of innocuous and noxious responses and to determine whether there are altered roles of CB2 receptors in models of persistent pain. Effects of local administration of the CB2 receptor agonist JWH-133 (5 and 15 microg/50 microL) on mechanically evoked responses of spinal wide dynamic range (WDR) neurons in noninflamed rats, rats with carrageenan-induced hindpaw inflammation, sham operated rats and spinal nerve-ligated (SNL) rats were determined in anaesthetized rats in vivo. Mechanical stimulation (von Frey filaments, 6-80 g) of the peripheral receptive field evoked firing of WDR neurons. Mechanically evoked responses of WDR neurons were similar in noninflamed, carrageenan-inflamed, sham-operated and SNL rats. Intraplantar injection of JWH-133 (15 microg), but not vehicle, significantly (P pain.

  5. Dynamics of pure tone audiometry and DPOAE changes induced by glycerol in Meniere's disease. (United States)

    Jablonka-Strom, Agnieszka; Pospiech, Lucyna; Zatonski, Maciej; Bochnia, Marek


    The purpose of this study is to follow up the dynamics of pure tone threshold and DPOAE amplitude changes induced by glycerol with reference to its activity in the inner ear. Selection was made among 38 patients with Meniere's disease for those having positive glycerol test. Pure-tone audiometry and DP-gram were performed in four series: as an initial examination before glycerol intake, 1, 2 and 3 h after. Audiometric changes formed distinct biphasal pattern at all frequencies between 250 and 4,000 Hz. The most dynamic pure tone threshold decrease occurred during the first hour. Between the first and second hour after glycerol ingestion there was a phase of no significant hearing changes. Further pure tone threshold decrease went on within the third hour reaching its top. Observing DPOAE changes, the highest DP amplitude growth occurred after the second and the third hour at DP-gram frequencies 2, 3 and 4 kHz. The fastest DP-amplitude increase was registered as well during the first hour after glycerol ingestion. In 11 persons with both audiometry and DPOAE positive glycerol test, parallel dynamics in the course of the glycerol test was observed. Biphasal glycerol test dynamics suggests the possibility of two mechanisms of glycerol activity in the inner ear.

  6. Cisplatin-based chemotherapy: Add high-frequency audiometry in the regimen

    Directory of Open Access Journals (Sweden)

    R Arora


    Full Text Available Background : Cisplatin-induced ototoxicity shows high interindividual variability and is often accompanied by transient or permanent tinnitus. It is not possible to identify the susceptible individuals before commencement of the treatment. We conducted a prospective, randomized and observational study in a tertiary care centre and evaluated the effects of different doses of cisplatin on hearing. Materials and Methods : Fifty-seven patients scheduled for cisplatin-based chemotherapy were included in the study. All patients were divided into three groups depending on the dose of cisplatin infused in 3 weeks. Results : The subjective hearing loss was found in seven patients, while six patients had tinnitus during the chemotherapy. The hearing loss was sensorineural, dose dependent, symmetrical, bilateral and irreversible. Higher frequencies were first to be affected in cisplatin chemotherapy. Conclusion : As use of high-frequency audiometry is still limited in research work only, we need a strict protocol of adding high-frequency audiometry in the cisplatin-based chemotherapy regimen.

  7. No evidence for early modulation of evoked responses in primary visual cortex to irrelevant probe stimuli presented during the attentional blink.

    Directory of Open Access Journals (Sweden)

    Oscar Jacoby

    Full Text Available BACKGROUND: During rapid serial visual presentation (RSVP, observers often miss the second of two targets if it appears within 500 ms of the first. This phenomenon, called the attentional blink (AB, is widely held to reflect a bottleneck in the processing of rapidly sequential stimuli that arises after initial sensory registration is complete (i.e., at a relatively late, post-perceptual stage of processing. Contrary to this view, recent fMRI studies have found that activity in the primary visual area (V1, which represents the earliest cortical stage of visual processing, is attenuated during the AB. Here we asked whether such changes in V1 activity during the AB arise in the initial feedforward sweep of stimulus input, or instead reflect the influence of feedback signals from higher cortical areas. METHODOLOGY/PRINCIPAL FINDINGS: EEG signals were recorded while participants monitored a sequential stream of distractor letters for two target digits (T1 and T2. Neural responses associated with an irrelevant probe stimulus presented simultaneously with T2 were measured using an ERP marker--the C1 component--that reflects initial perceptual processing of visual information in V1. As expected, T2 accuracy was compromised when the inter-target interval was brief, reflecting an AB deficit. Critically, however, the magnitude of the early C1 component evoked by the probe was not reduced during the AB. CONCLUSIONS/SIGNIFICANCE: Our finding that early sensory processing of irrelevant probe stimuli is not suppressed during the AB is consistent with theoretical models that assume that the bottleneck underlying the AB arises at a post-perceptual stage of processing. This suggests that reduced neural activity in V1 during the AB is driven by re-entrant signals from extrastriate areas that regulate early cortical activity via feedback connections with V1.

  8. A modelling study to inform specification and optimal electrode placement for imaging of neuronal depolarization during visual evoked responses by electrical and magnetic detection impedance tomography. (United States)

    Gilad, O; Horesh, L; Holder, D S


    Electrical impedance tomography (EIT) has the potential to achieve non-invasive functional imaging of fast neuronal activity in the human brain due to opening of ion channels during neuronal depolarization. Local changes of resistance in the cerebral cortex are about 1%, but the size and location of changes recorded on the scalp are unknown. The purpose of this work was to develop an anatomically realistic finite element model of the adult human head and use it to predict the amplitude and topography of changes on the scalp, and so inform specification for an in vivo measuring system. A detailed anatomically realistic finite element (FE) model of the head was produced from high resolution MRI. Simulations were performed for impedance changes in the visual cortex during evoked activity with recording of scalp potentials by electrodes or magnetic flux density by magnetoencephalography (MEG) in response to current injected with electrodes. The predicted changes were validated by recordings in saline filled tanks and with boundary voltages measured on the human scalp. Peak changes were 1.03 +/- 0.75 microV (0.0039 +/- 0.0034%) and 27 +/- 13 fT (0.2 +/- 0.5%) respectively, which yielded an estimated peak signal-to-noise ratio of about 4 for in vivo averaging over 10 min and 1 mA current injection. The largest scalp changes were over the occipital cortex. This modelling suggests, for the first time, that reproducible changes could be recorded on the scalp in vivo in single channels, although a higher SNR would be desirable for accurate image production. The findings suggest that an in vivo study is warranted in order to determine signal size but methods to improve SNR, such as prolonged averaging or other signal processing may be needed for accurate image production.

  9. The frequency modulated auditory evoked response (FMAER, a technical advance for study of childhood language disorders: cortical source localization and selected case studies

    Directory of Open Access Journals (Sweden)

    Duffy Frank H


    Full Text Available Abstract Background Language comprehension requires decoding of complex, rapidly changing speech streams. Detecting changes of frequency modulation (FM within speech is hypothesized as essential for accurate phoneme detection, and thus, for spoken word comprehension. Despite past demonstration of FM auditory evoked response (FMAER utility in language disorder investigations, it is seldom utilized clinically. This report's purpose is to facilitate clinical use by explaining analytic pitfalls, demonstrating sites of cortical origin, and illustrating potential utility. Results FMAERs collected from children with language disorders, including Developmental Dysphasia, Landau-Kleffner syndrome (LKS, and autism spectrum disorder (ASD and also normal controls - utilizing multi-channel reference-free recordings assisted by discrete source analysis - provided demonstratrions of cortical origin and examples of clinical utility. Recordings from inpatient epileptics with indwelling cortical electrodes provided direct assessment of FMAER origin. The FMAER is shown to normally arise from bilateral posterior superior temporal gyri and immediate temporal lobe surround. Childhood language disorders associated with prominent receptive deficits demonstrate absent left or bilateral FMAER temporal lobe responses. When receptive language is spared, the FMAER may remain present bilaterally. Analyses based upon mastoid or ear reference electrodes are shown to result in erroneous conclusions. Serial FMAER studies may dynamically track status of underlying language processing in LKS. FMAERs in ASD with language impairment may be normal or abnormal. Cortical FMAERs can locate language cortex when conventional cortical stimulation does not. Conclusion The FMAER measures the processing by the superior temporal gyri and adjacent cortex of rapid frequency modulation within an auditory stream. Clinical disorders associated with receptive deficits are shown to demonstrate absent

  10. National Survey of State Identification Audiometry Programs and Special Educational Services for Hearing Impaired Children and Youth United States: 1972. (United States)

    Gallaudet Coll., Washington, DC. Office of Demographic Studies.

    Reported were descriptive data concerning identification audiometry (hearing screening) and special educational programs for the hearing impaired. Data were provided in tabular format for each state in the country and the District of Columbia. Hearing screening program data included extent of coverage, grade or ages covered annually, year and…

  11. The ratio of the subjective audiometry in patients with acoustic trauma and “noisy” production workers

    Directory of Open Access Journals (Sweden)

    Shydlovska T.А.


    Full Text Available Introduction: The problem of diagnosis and treatment of sensorineural hearing loss (SHL, including forms developed under the influence of noise, takes one of the leading places in ot¬olaryngology. However, there are not many studies on acoustic trauma, although this problem has recently become more and more important. Objective: A comparison of subjective audiometry in patients with sensorineural hearing loss after acute acoustic trauma and chronic noise exposure. Materials and methods. In the work the results of exa¬mination of 84 patients with acoustic trauma, 15 healthy as the control group and 15 workers employed on 'noise' occupations as a comparison group are given. Subjective audiometry was fully carried out by clinical audiometer AC-40 «Interacoustics» (Denmark. Hearing indices were investigated in the conventional (0,125-8 kHz and extended (9-16 kHz frequency bands. Results: Subjective audiometry showed a reduction in sound perception in all patients. Ac¬cor¬ding to the threshold tone audiometry in patients with acoustic trauma hearing thresholds were authentically (P <0,05 increased by 4, 6 and 8 kHz tones of conventional (0,125-8 kHz frequency band and by 14-16 kHz tones of the extended (9-16 kHz in comparison with the control group, as with workers employed on noise occupations. All the examined patients had deterioration of speech-test audiometry and above-threshold audiometry. Conclusions: According to su¬b¬jective audiometry, the type similar disorders of auditory function are in patients with acoustic trauma as in patients with long-term noise exposure, but they are more pronounced and develop much faster. The most informative features which show the origin and progression of hearing loss in patients with acoustic trauma are: increasing hearing thresholds by 14 and 16 kHz tones of the extended (9-16 kHz frequency band and by 4, 6 and 8 kHz tones of con¬ven¬tional (0,125-8 kHz frequency band plus the reduction of

  12. Monosyllable speech audiometry in noise-exposed workers—consonant and vowel confusion (United States)

    Miyakita, T.; Miura, H.


    To obtain basic data for evaluating the hearing handicaps experienced by workers with noise-induced hearing loss, the ability to distinguish monosyllables was examined by speech audiometry. The percentage of correct scores for each monosyllable varied widely in 88 male workers, depending on the presentation level and the severity of hearing loss. A 67-S word list (prepared by the Japan Audiological Society), consisting of 20 Japanese monosyllables (17 consonant-vowel (CV) syllables and three vowel syllables), was used to evaluate consonant and vowel confusion at the level of 20 to 90 dB ( re HL at 1000 Hz [9]). Regarding the confusion among five subsequent vowel nuclei, we observed particular confusion patterns resulting from the similarity of the first formant (F1). Analysis of the tendency toward confusion among individual monosyllables together with the audiometric configuration will provide useful information for evaluating noise-induced hearing loss.

  13. 年龄对言语诱发 ABR 的频率跟随反应影响%The Effects of Aging on Frequency Following Response in Speech Evoked Auditory Brainstem Response

    Institute of Scientific and Technical Information of China (English)

    郝文洋; 商莹莹; 倪道凤; 姜鸿; 徐春晓; 高志强; 王素菊; 李奉蓉; 赵翠霞


    Objective This study was to record the speech evoked auditory brainstem response (s-ABR) of normal hearing young and aged people ,then compared the frequency following responses (FFR) of s-ABR between the two groups ,in order to explore the contribution of FFR on revealing possible aging mechanisms of central audi‐tory system .Methods Twelve normal hearing young adults and aged people respectively (24 ears) were enrolled and s-ABRs (syllable/da/) were recorded using a SmartEP auditory evoked potential system .Results The comparison of waveforms between the two groups showed that the wave latencies of transient responses in the aged group was longer than that of young group ,while the wave latencies of the sustained response ,FFR ,were of no significant differences .The amplitudes of FFR waves in the aged group were lower than those of in the young group .The FFR spectrum analysis showed that the relative energy of each formant for the aged group was lower than that of in the young group and for some formants .Moreover ,for the aged group ,formant frequency differences between FFR and stimulus signal were greater than the young group .Conclusion Compared with young people ,the FFR of aged peo‐ple showed lower amplitudes and less accuracy ,meaning that aging can lead to the weakness of the brainstem neurons'spectral encoding ability .It may be one of the mechanisms causing the reduction of speech recognition in presbycusis patients .%目的:分析听力正常青年人与老年人之间言语诱发听性脑干反应(speech evoked auditory brainstem response ,s-ABR)的频率跟随反应(frequency following response ,FFR)差异,探讨其在揭示听觉系统老化机制中的作用。方法应用SmartEP听觉诱发电位系统对听力正常青年人(18~25岁)与老年人(60~70岁)各12例(24耳)进行言语声信号/da/诱发的s-ABR检测,比较两组s -ABR波形图及频谱图、FFR各波潜伏期及共振峰等。结

  14. Accuracy of Mobile-Based Audiometry in the Evaluation of Hearing Loss in Quiet and Noisy Environments. (United States)

    Saliba, Joe; Al-Reefi, Mahmoud; Carriere, Junie S; Verma, Neil; Provencal, Christiane; Rappaport, Jamie M


    Objectives (1) To compare the accuracy of 2 previously validated mobile-based hearing tests in determining pure tone thresholds and screening for hearing loss. (2) To determine the accuracy of mobile audiometry in noisy environments through noise reduction strategies. Study Design Prospective clinical study. Setting Tertiary hospital. Subjects and Methods Thirty-three adults with or without hearing loss were tested (mean age, 49.7 years; women, 42.4%). Air conduction thresholds measured as pure tone average and at individual frequencies were assessed by conventional audiogram and by 2 audiometric applications (consumer and professional) on a tablet device. Mobile audiometry was performed in a quiet sound booth and in a noisy sound booth (50 dB of background noise) through active and passive noise reduction strategies. Results On average, 91.1% (95% confidence interval [95% CI], 89.1%-93.2%) and 95.8% (95% CI, 93.5%-97.1%) of the threshold values obtained in a quiet sound booth with the consumer and professional applications, respectively, were within 10 dB of the corresponding audiogram thresholds, as compared with 86.5% (95% CI, 82.6%-88.5%) and 91.3% (95% CI, 88.5%-92.8%) in a noisy sound booth through noise cancellation. When screening for at least moderate hearing loss (pure tone average >40 dB HL), the consumer application showed a sensitivity and specificity of 87.5% and 95.9%, respectively, and the professional application, 100% and 95.9%. Overall, patients preferred mobile audiometry over conventional audiograms. Conclusion Mobile audiometry can correctly estimate pure tone thresholds and screen for moderate hearing loss. Noise reduction strategies in mobile audiometry provide a portable effective solution for hearing assessments outside clinical settings.

  15. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.;


    to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

  16. A Comparison of Aided Hearing Thresholds by Behavioral Audiometry and Auditory Steady-state Response in Sound Field%声场中记录的听性稳态助听反应阈与行为测试助听听阈的相关性

    Institute of Scientific and Technical Information of China (English)

    邹建华; 蓝小兵; 林琳; 李光智


    ObjectiveTo evaluate the aided hearing thresholds by using multiple-frequency auditory steady-state response (ASSR) to Chirp stimuli in sound field, to observe its correlation with behavioral aided hearing thresholds and to explore the clinical significance of ASSR to Chirp stimuli in evaluation of hearing aid outcome. Methods Twenty-two severely hearing-impaired children (39 ears)with hearing aids received the examination with Eclipse EP25 ASSR device and GSS-61 audiometer to obtain their aided hearing thresholds. Sixteen normal-hearing children (32 ears) received the examination to obtain their behavioral thresholds and ASSR thresholds. Results For the hearing-impaired group, the coefficients of ASSR and behavioral aided hearing thresholds were 0.65,0.68,0.77 and 0.82 at 0.5,1,2 and 4 kHz, respectively(P<0.01), which indicated there were correlations between the two test results. The paired t-test showed that there were significant differences between behavioral thresholds and ASSR thresholds of normal group at 0.5, 1, 2 and 4 kHz(P<0.01). The ASSR thresholds were 20-30 dB HL higher than behavioral thresholds, Conclusion The ASSR to Chirp stimuli can be used to evaluate the hearing aid outcomes in clinical practice.%目的 应用多频听觉稳态反应(ASSR)Chirp刺激信号在声场中测试助听反应阈,观察其阈值与行为测试助听听阈的相关性,探讨多频听觉稳态反应Chirp刺激信号声场测试评估助听器补偿效果的临床意义.方法 选取22例(39耳)重度感音神经性听力损失、已配戴助听器的患儿(听障组)和16例(32耳)听力正常儿童(对照组)为研究对象.应用国际听力Eclipse EP25型多频稳态诱发电位仪及美国GSI-61型听力计,分别对听障组在声场中使用两种仪器测试助听听阈;对对照组进行裸耳行为听阈与声场中听觉稳态反应阈测试.结果 在0.5、1、2、4 kHz处,听障组ASSR助听反应阈与行为助听听阈的相关系数分别为0.65、0.68

  17. A preliminary study on the correlation of electrically evoked auditory brainstem response and electrically evoked compound action potential with the inserting depth of cochlear electrode%EABR与人工耳蜗电极植入深度关系的初步研究

    Institute of Scientific and Technical Information of China (English)

    陈静; 谢景华; 丁秀勇; 李悦; 高志强


    目的 初步探讨人工耳蜗电极植入深度和术后电诱发听性脑干反应(EABR,Electrically evoked auditory brainstem responses)及电诱发听神经复合动作电位(electrically evoked compound actionpotentials,ECAP)的相关性. 方法 选取耳蜗形态正常植入奥地利标准电极患者24例,术后头颅侧位片检查判断电极全植入. 根据电极耳蜗内位置分为E9-E12耳蜗底区、E5-E8耳蜗中区、E1-E4耳蜗顶区三部分,分别记录各区域EABR阈值及波形特点和对应区域的ECAP阈值,分析其间相关性. 结果蜗顶部、蜗中部、蜗底部EABR引出率分别为87.50%,83.33%,79.16%;ECAP引出率分别为91.67%,79.17%,75%;EABR波V阈值为分别为(20.13±5.91)qu,(22.98±4.82)qu,(26.71±6.25)qu;ECAP阈值分别为 (21.61±4.18)qu,(23.28±3.70)qu,(29.18±3.74)qu.结论 蜗顶部和蜗中部EABR及ECAP引出率高于蜗底部,自蜗顶区至蜗底区EABR和EACP阈值依次增高,相同植入深度电极的EABR阈值低于ECAP阈值.%Objective To explore the correlation of electrically evoked auditory brain stem response (EABR) and electrically evoked compound action potential (ECAP) with the inserting depth of cochlear electrode. Methods EABR and ECAP recordings were carried out among 24 subjects with MED-EL standard cochlear electrode array implanted. With the electrode insertion depth assayed by lateral cranial X-ray photography, these evoked potential recordings were then analyzed, based on the definition of electrode placed locations in the regions of apical (E1-E4), middle (E5-E8) and basal (E9-E12) to determine if the threshold and latency differ depending on the region stimulated. Results At the locations of apical, middle and basal region, the positive recording rate was 87.50%, 83.33% and 79.16% for EABR, and that was 91.67%, 79.17%, 75% fro ECAP, with the thresholds of EABR at eV were (20.13±5.91)qu, (22.98±4.82)qu and (26.71±6.25)qu and those of ECAP were (21.61±4.18)qu, (23.28±3.70)qu, (29.18±3

  18. Methylglyoxal evokes pain by stimulating TRPA1.

    Directory of Open Access Journals (Sweden)

    David A Andersson

    Full Text Available Diabetic neuropathy is a severe complication of long-standing diabetes and one of the major etiologies of neuropathic pain. Diabetes is associated with an increased formation of reactive oxygen species and the electrophilic dicarbonyl compound methylglyoxal (MG. Here we show that MG stimulates heterologously expressed TRPA1 in CHO cells and natively expressed TRPA1 in MDCK cells and DRG neurons. MG evokes [Ca(2+]i-responses in TRPA1 expressing DRG neurons but is without effect in neurons cultured from Trpa1(-/- mice. Consistent with a direct, intracellular action, we show that methylglyoxal is significantly more potent as a TRPA1 agonist when applied to the intracellular face of excised membrane patches than to intact cells. Local intraplantar administration of MG evokes a pain response in Trpa1(+/+ but not in Trpa1(-/- mice. Furthermore, persistently increased MG levels achieved by two weeks pharmacological inhibition of glyoxalase-1 (GLO-1, the rate-limiting enzyme responsible for detoxification of MG, evokes a progressive and marked thermal (cold and heat and mechanical hypersensitivity in wildtype but not in Trpa1(-/- mice. Our results thus demonstrate that TRPA1 is required both for the acute pain response evoked by topical MG and for the long-lasting pronociceptive effects associated with elevated MG in vivo. In contrast to our observations in DRG neurons, MG evokes indistinguishable [Ca(2+]i-responses in pancreatic β-cells cultured from Trpa1(+/+ and Trpa1(-/- mice. In vivo, the TRPA1 antagonist HC030031 impairs glucose clearance in the glucose tolerance test both in Trpa1(+/+ and Trpa1(-/- mice, indicating a non-TRPA1 mediated effect and suggesting that results obtained with this compound should be interpreted with caution. Our results show that TRPA1 is the principal target for MG in sensory neurons but not in pancreatic β-cells and that activation of TRPA1 by MG produces a painful neuropathy with the behavioral hallmarks of diabetic

  19. [Implementation of the new quality assurance agreement for the fitting of hearing aids in daily practice. Part 2: New diagnostic aspects of speech audiometry]. (United States)

    Löhler, J; Akcicek, B; Wollenberg, B; Schönweiler, R


    Upon review of the statutory health insurance reimbursement guidelines, a specific quality assurance questionnaire concerned with the provision of hearing aids was introduced that assesses elements of patient satisfaction within Germany's public healthcare system. APHAB questionnaire-based patient evaluation of the benefit of hearing aids represents the third pillar of audiological diagnostics, alongside classical pure-tone and speech audiometry. Another new aspect of the national guidelines is inclusion of free-field measurements in noise with and without hearing aids. Part 2 of this review describes new diagnostic aspects of speech audiometry. In addition to adaptive speech audiometry, a proposed method for applying the gold standard of speech audiometry - the Freiburg monosyllabic speech test - in noise is described. Finally, the quality assurance questionnaire will be explained as an appendix to template 15 of the regulations governing hearing aids.

  20. The role of ultrahigh-frequency audiometry in the early detection of systemic drug-induced hearing loss. (United States)

    Singh Chauhan, Rajeev; Saxena, Ravinder Kumar; Varshey, Saurabh


    In monitoring patients for drug-induced hearing loss, most audiometric evaluations are limited to the range of frequencies from 0.25 to 8 kHz. However, such testing would fail to detect ototoxicity in patients who have already experienced hearing loss in the ultrahigh frequencies from 10 to 20 kHz. Awareness of ultrahigh-frequency ototoxicity could lead to changes in a drug regimen to prevent further damage. We conducted a prospective study of 105 patients who were receiving a potentially ototoxic drug-either gentamicin, amikacin, or cisplatin-to assess the value of ultrahigh-frequency audiometry in detecting systemic drug-induced hearing loss. We found that expanding audiometry into the ultrahigh-frequency range led to the detection of a substantial number of cases of hearing loss that would have otherwise been missed.

  1. Degranulation of mast cells located in median eminence in response to compound 48/80 evokes adrenocortical secretion via histamine and CRF in dogs. (United States)

    Matsumoto, Itsuro; Inoue, Yasuhisa; Tsuchiya, Katsuhiko; Shimada, Toshio; Aikawa, Tadaomi


    The effect of intracerebroventricular infusion of compound 48/80 (C48/80), a mast cell secretagogue, on adrenal cortisol secretion was investigated in dogs under pentobarbital sodium anesthesia. A marked increase in adrenal cortisol secretion was elicited by C48/80 along with a concomitant increase in the plasma levels of cortisol and immunoreactive ACTH, but neither arterial blood pressure and heart rate nor the plasma histamine level altered significantly. Pretreatment with either anti-CRF antiserum or pyrilamine maleate (H(1) histamine-receptor antagonist) significantly attenuated the C48/80-evoked increase in cortisol secretion, but pretreatment with metiamide (H(2)-receptor antagonist) significantly potentiated it. Significant attenuation of the C48/80-evoked increase in cortisol also occurred in dogs given ketotifen, a mast cell stabilizing drug, before pharmacologic challenge. In the pars tuberalis and median eminence (ME), mast cells were highly concentrated in close association with the primary plexus of the hypophysial portal system. Degranulated mast cells were extensively found in the ME of C48/80-treated animals. These results suggest that mast cells located in these regions liberated histamine within the brain as a result of degranulation induced by C48/80 and that this led to activation of the hypothalamic-pituitary-adrenocortical axis.

  2. Audiological assessment value of click-evoked auditory brainstem response combined with single stimulation of the auditory steady-state evoked response on normal young people%听性脑干诱发电位结合单刺激听觉稳态诱发反应对正常青年人听阈正常值评估的探讨

    Institute of Scientific and Technical Information of China (English)

    李倩庆; 宋江顺; 刘文婷


    目的 分析正常青年人多频刺激听觉稳态诱发电位(multiple stimuli auditory steady-state response,m-ASSR)、单频刺激听觉稳态诱发电位(single stimulusauditory steady-state response,s-ASSR)、听性脑干诱发电位(click-evoked auditory brain stem response,CABR)、纯音听力测试(pure tone auditory,PTA)阈值,探讨C-ABR结合0.5、1 kHz s-ASSR在正常青年人中反应阈的正常值.方法 对听力正常青年人(43人,共86耳)分别行PTA、m-ASSR、0.5、1.0 kHz s-ASSR、C-ABR检查.将PTA、m-ASSR、听力测试组合(C-ABR结合0.5、1 kHzs-ASSR反应阈)结果行f检验、线性回归分析等统计学分析.结果 ①0.5、1、2、4 kHz处,听力测试组合反应阈高于PTA;除1 kHz外其他频率均较m-ASSR反应阈接近PTA;②0.5、1、2、4 kHz处,听力测试组合反应阈预测PTA的回归方程分别为:y=0.75x-4.53,y=0.56x-4.46,y=0.62x-7.70和y=0.92x-12.66.结论 正常青年人中ASSR反应阈与PTA、C-ABR V波反应阈有一定的差值;听力测试组合较m-ASSR更接近PTA;听力测试组合可以更准确、更可靠评估正常成年人听阈水平.

  3. Differentiation of sensorimotor neuronal structures responsible for induction of motor evoked potentials, attenuation in detection of somatosensory stimuli, and induction of sensation of movement by mapping of optimal current directions. (United States)

    Pascual-Leone, A; Cohen, L G; Brasil-Neto, J P; Valls-Solé, J; Hallett, M


    Transcranial magnetic stimulation (TMS) of the sensorimotor cortex can evoke motor evoked potentials (MEPs), attenuation in detection of somatosensory stimuli (ADSS), and sensation of movement (SOM) referred to the same body part. In this study we tried to differentiate the substrates responsible for these effects. In 6 normal volunteers, TMS was applied with a nearly monopolar Dantec stimulator and a butterfly coil. Optimal scalp location and current direction were determined for induction of MEPs in abductor pollicis brevis (APB), first dorsal interosseous (FDI), and adductor digiti minimi (ADM); SOM in digits 2 and 5 in an ischemically paralyzed hand; and ADSS applied to digits 2 and 5. All 3 muscles' MEPs and SOM and ADSS in both digits were optimally activated from a single scalp position. In all subjects, optimal current directions for MEPs pointed anteriorly; those for ADSS and SOM pointed posteriorly. Optimal current directions showed the same progression in all subjects for MEPs (ADM, FDI, and APB from antero-lateral to antero-medial), ADSS (digit 5 postero-medial, 2 postero-lateral), and SOM (digit 1 through 5 postero-lateral to postero-medial). We conclude that neuronal networks targeting corticospinal neurons responsible for MEPs are different from those leading to SOM and ADSS (which could not be differentiated).

  4. International Evoked Potentials Symposium

    CERN Document Server


    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  5. Modeling auditory evoked potentials to complex stimuli

    DEFF Research Database (Denmark)

    Rønne, Filip Munch

    The auditory evoked potential (AEP) is an electrical signal that can be recorded from electrodes attached to the scalp of a human subject when a sound is presented. The signal is considered to reflect neural activity in response to the acoustic stimulation and is a well established clinical...... clinically and in research towards using realistic and complex stimuli, such as speech, to electrophysiologically assess the human hearing. However, to interpret the AEP generation to complex sounds, the potential patterns in response to simple stimuli needs to be understood. Therefore, the model was used...... to simulate auditory brainstem responses (ABRs) evoked by classic stimuli like clicks, tone bursts and chirps. The ABRs to these simple stimuli were compared to literature data and the model was shown to predict the frequency dependence of tone-burst ABR wave-V latency and the level-dependence of ABR wave...

  6. Music evokes vivid autobiographical memories. (United States)

    Belfi, Amy M; Karlan, Brett; Tranel, Daniel


    Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.

  7. Adjective metaphors evoke negative meanings. (United States)

    Sakamoto, Maki; Utsumi, Akira


    Previous metaphor studies have paid much attention to nominal metaphors and predicative metaphors, but little attention has been given to adjective metaphors. Although some studies have focused on adjective metaphors, they only examined differences in the acceptability of various types of adjective metaphors. This paper explores the cognitive effects evoked by adjective metaphors. Three psychological experiments revealed that (1) adjective metaphors, especially those modified by color adjectives, tend to evoke negative effect; (2) although the meanings of metaphors are basically affected by the meanings of their vehicles, when a vehicle has a neutral meaning, negative meanings are evoked most frequently for adjective metaphors compared to nominal and predicative metaphors; (3) negative meanings evoked by adjective metaphors are related to poeticness, and poetic metaphors evoke negative meanings more easily than less poetic metaphors. Our research sheds new light on studies of the use of metaphor, which is one of the most basic human cognitive abilities.

  8. Ocular Vestibular Evoked Myogenic Potentials

    Directory of Open Access Journals (Sweden)

    Felipe, Lilian


    Full Text Available Introduction Diagnostic testing of the vestibular system is an essential component of treating patients with balance dysfunction. Until recently, testing methods primarily evaluated the integrity of the horizontal semicircular canal, which is only a portion of the vestibular system. Recent advances in technology have afforded clinicians the ability to assess otolith function through vestibular evoked myogenic potential (VEMP testing. VEMP testing from the inferior extraocular muscles of the eye has been the subject of interest of recent research. Objective To summarize recent developments in ocular VEMP testing. Results Recent studies suggest that the ocular VEMP is produced by otolith afferents in the superior division of the vestibular nerve. The ocular VEMP is a short latency potential, composed of extraocular myogenic responses activated by sound stimulation and registered by surface electromyography via ipsilateral otolithic and contralateral extraocular muscle activation. The inferior oblique muscle is the most superficial of the six extraocular muscles responsible for eye movement. Therefore, measurement of ocular VEMPs can be performed easily by using surface electrodes on the skin below the eyes contralateral to the stimulated side. Conclusion This new variation of the VEMP procedure may supplement conventional testing in difficult to test populations. It may also be possible to use this technique to evaluate previously inaccessible information on the vestibular system.

  9. Use of the novel contact heat evoked potential stimulator (CHEPS for the assessment of small fibre neuropathy: correlations with skin flare responses and intra-epidermal nerve fibre counts

    Directory of Open Access Journals (Sweden)

    Chizh Boris A


    Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS rapidly stimulates cutaneous small nerve fibres, and resulting evoked potentials can be recorded from the scalp. We have studied patients with symptoms of sensory neuropathy and controls using CHEPS, and validated the findings using other objective measures of small nerve fibres i.e. the histamine-induced skin flare response and intra-epidermal fibres (IEF, and also quantitative sensory testing (QST, a subjective measure. Methods In patients with symptoms of sensory neuropathy (n = 41 and healthy controls (n = 9 we performed clinical examination, QST (monofilament, vibration and thermal perception thresholds, nerve conduction studies, histamine-induced skin flares and CHEPS. Skin punch biopsies were immunostained using standard ABC immunoperoxidase for the nerve marker PGP 9.5 or the heat and capsaicin receptor TRPV1. Immunoreactive IEF were counted per length of tissue section and epidermal thickness recorded. Results Amplitudes of Aδ evoked potentials (μV following face, arm or leg stimulation were reduced in patients (e.g. for the leg: mean ± SEM – controls 11.7 ± 1.95, patients 3.63 ± 0.85, p = 0.0032. Patients showed reduced leg skin flare responses, which correlated with Aδ amplitudes (rs = 0.40, p = 0.010. In patient leg skin biopsies, PGP 9.5- and TRPV1-immunoreactive IEF were reduced and correlated with Aδ amplitudes (PGP 9.5, rs = 0.51, p = 0.0006; TRPV1, rs = 0.48, p = 0.0012. Conclusion CHEPS appears a sensitive measure, with abnormalities observed in some symptomatic patients who did not have significant IEF loss and/or QST abnormalities. Some of the latter patients may have early small fibre dysfunction or ion channelopathy. CHEPS provides a clinically practical, non-invasive and objective measure, and can be a useful additional tool for the assessment of sensory small fibre neuropathy. Although further evaluation is required, the technique shows

  10. Examination of Hearing in a Rheumatoid Arthritis Population: Role of Extended-High-Frequency Audiometry in the Diagnosis of Subclinical Involvement. (United States)

    Lasso de la Vega, Mar; Villarreal, Ithzel Maria; Lopez-Moya, Julio; Garcia-Berrocal, Jose Ramon


    Objective. The aim of this study is to analyze the high-frequency hearing levels in patients with rheumatoid arthritis and to determine the relationship between hearing loss, disease duration, and immunological parameters. Materials and Methods. A descriptive cross-sectional study including fifty-three patients with rheumatoid arthritis was performed. The control group consisted of 71 age- and sex-matched patients from the study population (consecutively recruited in Madrid "Area 9," from January 2010 to February 2011). Both a pure tone audiometry and an extended-high-frequency audiometry were performed. Results. Extended-high-frequency audiometry diagnosed sensorineural hearing loss in 69.8% of the patients which exceeded the results obtained with pure tone audiometry (43% of the patients). This study found significant correlations in patients with sensorineural hearing loss related to age, sex, and serum anti-cardiolipin (aCL) antibody levels. Conclusion. Sensorineural hearing loss must be considered within the clinical context of rheumatoid arthritis. Our results demonstrated that an extended-high-frequency audiometry is a useful audiological test that must be performed within the diagnostic and follow-up testing of patients with rheumatoid arthritis, providing further insight into a disease-modifying treatment or a hearing loss preventive treatment.

  11. Cortical Responsiveness to Nociceptive Stimuli in Patients with Chronic Disorders of Consciousness: Do C-Fiber Laser Evoked Potentials Have a Role?

    Directory of Open Access Journals (Sweden)

    Antonino Naro

    Full Text Available It has been shown that the presence of Aδ-fiber laser evoked potentials (Aδ-LEP in patients suffering from chronic disorders of consciousness (DOC, such as vegetative state (VS and minimally conscious state (MCS, may be the expression of a residual cortical pain arousal. Interestingly, the study of C-fiber LEP (C-LEP could be useful in the assessment of cortical pain arousal in the DOC individuals who lack of Aδ-LEP. To this end, we enrolled 38 DOC patients following post-anoxic or post-traumatic brain injury, who met the international criteria for VS and MCS diagnosis. Each subject was clinically evaluated, through the coma recovery scale-revised (CRS-R and the nociceptive coma scale-revised (NCS-R, and electrophysiologically tested by means of a solid-state laser for Aδ-LEP and C-LEP. VS individuals showed increased latencies and reduced amplitudes of both the Aδ-LEP and C-LEP components in comparison to MCS patients. Although nearly all of the patients had both the LEP components, some VS individuals showed only the C-LEP ones. Notably, such patients had a similar NCS-R score to those having both the LEP components. Hence, we could hypothesize that C-LEP generators may be rearranged or partially spared in order to still guarantee cortical pain arousal when Aδ-LEP generators are damaged. Therefore, the residual presence of C-LEP should be assessed when Aδ-LEP are missing, since a potential pain experience should be still present in some patients, so to properly initiate, or adapt, the most appropriate pain treatment.

  12. Cortical Responsiveness to Nociceptive Stimuli in Patients with Chronic Disorders of Consciousness: Do C-Fiber Laser Evoked Potentials Have a Role? (United States)

    Naro, Antonino; Russo, Margherita; Leo, Antonino; Rifici, Carmela; Pollicino, Patrizia; Bramanti, Placido; Calabrò, Rocco Salvatore


    It has been shown that the presence of Aδ-fiber laser evoked potentials (Aδ-LEP) in patients suffering from chronic disorders of consciousness (DOC), such as vegetative state (VS) and minimally conscious state (MCS), may be the expression of a residual cortical pain arousal. Interestingly, the study of C-fiber LEP (C-LEP) could be useful in the assessment of cortical pain arousal in the DOC individuals who lack of Aδ-LEP. To this end, we enrolled 38 DOC patients following post-anoxic or post-traumatic brain injury, who met the international criteria for VS and MCS diagnosis. Each subject was clinically evaluated, through the coma recovery scale-revised (CRS-R) and the nociceptive coma scale-revised (NCS-R), and electrophysiologically tested by means of a solid-state laser for Aδ-LEP and C-LEP. VS individuals showed increased latencies and reduced amplitudes of both the Aδ-LEP and C-LEP components in comparison to MCS patients. Although nearly all of the patients had both the LEP components, some VS individuals showed only the C-LEP ones. Notably, such patients had a similar NCS-R score to those having both the LEP components. Hence, we could hypothesize that C-LEP generators may be rearranged or partially spared in order to still guarantee cortical pain arousal when Aδ-LEP generators are damaged. Therefore, the residual presence of C-LEP should be assessed when Aδ-LEP are missing, since a potential pain experience should be still present in some patients, so to properly initiate, or adapt, the most appropriate pain treatment. PMID:26674634

  13. The Auditory-Evoked N2 and P3 Components in the Stop-Signal Task: Indices of Inhibition, Response-Conflict or Error-Detection? (United States)

    Dimoska, Aneta; Johnstone, Stuart J.; Barry, Robert J.


    The N2 and P3 components have been separately associated with response inhibition in the stop-signal task, and more recently, the N2 has been implicated in the detection of response-conflict. To isolate response inhibition activity from early sensory processing, the present study compared processing of the stop-signal with that of a…

  14. Multiple Color Stimulus Induced Steady State Visual Evoked Potentials (United States)


    evoked potentials, multiple color, FFT, bispectrum I. INTRODUCTION Visual evoked potential ( VEP ) is the electrical response of...brain under visual stimulation, which can be recorded from the scalp over the visual cortex of the brain. A distinction is made between transient VEP ...and steady-state VEP (SSVEP) based on the stimulation frequencies. The former arises when the stimulation frequencies are less than 2 Hz. However


    Yilmaz, Ugur; Vicars, Brenda; Yang, Claire C.


    We investigated the autonomic innervation of the penis by using evoked cavernous activity (ECA). We recruited 7 males with thoracic spinal cord injury (SCI) and sexual dysfunction and 6 males who were scheduled to have pelvic surgery (PS), specifically non-nerve-sparing radical cystoprostatectomy. In the PS subjects, ECA was performed both pre- and postoperatively. The left median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into the right and left cavernous bodies. We simultaneously recorded hand and foot sympathetic skin responses (SSRs) as controls. In the SCI group, all but one subject had reproducible hand SSRs. None of these subjects had ECA or foot SSRs. All the PS subjects had reproducible ECA and SSRs, both preoperatively and postoperatively. There was no difference in the latency and amplitude measurements of ECA and SSRs in the postoperative compared to the preoperative period (p>0.05). In conclusion, ECA is absent in men with SCI above the sympathetic outflow to the genitalia. In men following radical pelvic surgery, ECA is preserved, indicating the preservation of sympathetic fibers. PMID:19609298

  16. Do ambient urban odors evoke basic emotions?

    Directory of Open Access Journals (Sweden)

    Sandra Theresia Weber-Glass


    Full Text Available Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman’s (Ekman et al., 1983 basic emotions happiness, surprise, anger, fear, sadness and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles / bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the skin conductance response and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles / bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  17. [The potential of tone audiometry for the determination of the sound-absorbing properties of various materials]. (United States)

    Zinkin, V N; Sheshegov, P M


    The objective of the present work was to experimentally estimate the potential of the tone audiometry technique for the determination of the sound-absorbing properties of various material. The study included 15 subjects at the age from 19 to 32 years. Their audiological examination was followed by the placement of the 5×7 cm spacer plate from the study material beneath the bone vibrator telephone to determine the bone sound-conduction threshold; no air-marking was undertaken. The sound absorption by the study materials of interest was determined in each octave-band from 250 to 8000 Hz from the difference between the starting audiogram and the audiogram of the material of interest. The study was carried out in three stages: (1) evaluation of sound absorption of each of the five materials, (2) measurement of the same parameter in the combinations of 2--4 layers for increasing sound absorption, and (3) fixation of the bone conduction telephone by the operator's hand (the head-mounted harness was used for the same purpose at stages 1 and 2). The experiments demonstrated that the study of bone sound conduction by means of tone audiometry allows to estimate the sound absorption of various materials. This technique may be applied for the development of a subjective method for the measurement of sound absorption in order to evaluate the acoustic effectiveness of materials that can be used to construct individual protective anti-noise devices.

  18. [Exploration of the optic and somatosensory pathways with cerebral evoked potentials]. (United States)

    Ghezzi, A; Zibetti, A


    Visual and somatosensorial evoked potentials are the electrical response, recorded on the scalp, that follows the presentation of visual and sensorial stimuli. After briefly mentioning the technical premises enabling evoked responses to be obtained from EEC activity, some cases are reported (demyelining, degenerative, compressive, ischaemic, anoxic pathology) where visual or sensory evoked potentials presented changes, proof of the usefulness of these techniques for the purposes of clinical documentation or for diagnosis in different fields of DNS pathology.

  19. The μ opioid agonist morphine modulates potentiation of capsaicin-evoked TRPV1 responses through a cyclic AMP-dependent protein kinase A pathway

    Directory of Open Access Journals (Sweden)

    Roberts-Thomson Sarah J


    Full Text Available Abstract Background The vanilloid receptor 1 (TRPV1 is critical in the development of inflammatory hyperalgesia. Several receptors including G-protein coupled prostaglandin receptors have been reported to functionally interact with the TRPV1 through a cAMP-dependent protein kinase A (PKA pathway to potentiate TRPV1-mediated capsaicin responses. Such regulation may have significance in inflammatory pain. However, few functional receptor interactions that inhibit PKA-mediated potentiation of TRPV1 responses have been described. Results In the present studies we investigated the hypothesis that the μ opioid receptor (MOP agonist morphine can modulate forskolin-potentiated capsaicin responses through a cAMP-dependent PKA pathway. HEK293 cells were stably transfected with TRPV1 and MOP, and calcium (Ca2+ responses to injection of the TRPV1 agonist capsaicin were monitored in Fluo-3-loaded cells. Pre-treatment with morphine did not inhibit unpotentiated capsaicin-induced Ca2+ responses but significantly altered capsaicin responses potentiated by forskolin. TRPV1-mediated Ca2+ responses potentiated by the direct PKA activator 8-Br-cAMP and the PKC activator Phorbol-12-myristate-13-acetatewere not modulated by morphine. Immunohistochemical studies confirmed that the TRPV1 and MOP are co-expressed on cultured Dorsal Root Ganglion neurones, pointing towards the existence of a functional relationship between the G-protein coupled MOP and nociceptive TRPV1. Conclusion The results presented here indicate that the opioid receptor agonist morphine acts via inhibition of adenylate cyclase to inhibit PKA-potentiated TRPV1 responses. Targeting of peripheral opioid receptors may therefore have therapeutic potential as an intervention to prevent potentiation of TRPV1 responses through the PKA pathway in inflammation.

  20. Do ambient urban odors evoke basic emotions? (United States)

    Glass, Sandra T; Lingg, Elisabeth; Heuberger, Eva


    Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman's (Ekman et al., 1983) basic emotions happiness, surprise, anger, fear, sadness, and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles/bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate, and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response (SCR) varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the SCR and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles/bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  1. A joint sparse representation-based method for double-trial evoked potentials estimation. (United States)

    Yu, Nannan; Liu, Haikuan; Wang, Xiaoyan; Lu, Hanbing


    In this paper, we present a novel approach to solving an evoked potentials estimating problem. Generally, the evoked potentials in two consecutive trials obtained by repeated identical stimuli of the nerves are extremely similar. In order to trace evoked potentials, we propose a joint sparse representation-based double-trial evoked potentials estimation method, taking full advantage of this similarity. The estimation process is performed in three stages: first, according to the similarity of evoked potentials and the randomness of a spontaneous electroencephalogram, the two consecutive observations of evoked potentials are considered as superpositions of the common component and the unique components; second, making use of their characteristics, the two sparse dictionaries are constructed; and finally, we apply the joint sparse representation method in order to extract the common component of double-trial observations, instead of the evoked potential in each trial. A series of experiments carried out on simulated and human test responses confirmed the superior performance of our method.

  2. Linear superposition of sensory-evoked and ongoing cortical hemodynamics

    Directory of Open Access Journals (Sweden)

    Mohamad Saka


    Full Text Available Modern non-invasive brain imaging techniques utilise changes in cerebral blood flow, volume and oxygenation that accompany brain activation. However, stimulus-evoked hemodynamic responses display considerable inter-trial variability even when identical stimuli are presented and the sources of this variability are poorly understood. One of the sources of this response variation could be ongoing spontaneous hemodynamic fluctuations. To investigate this issue, 2-dimensional optical imaging spectroscopy was used to measure cortical hemodynamics in response to sensory stimuli in anaesthetised rodents Pre-stimulus cortical hemodynamics displayed spontaneous periodic fluctuations and as such, data from individual stimulus presentation trials were assigned to one of four groups depending on the phase angle of pre-stimulus hemodynamic fluctuations and averaged. This analysis revealed that sensory evoked cortical hemodynamics displayed distinctive response characteristics and magnitudes depending on the phase angle of ongoing fluctuations at stimulus onset. To investigate the origin of this phenomenon, ‘null-trails’ were collected without stimulus presentation. Subtraction of phase averaged ‘null trials’ from their phase averaged stimulus-evoked counterparts resulted in four similar time series that resembled the mean stimulus-evoked response. These analyses suggest that linear superposition of evoked and ongoing cortical hemodynamic changes may be a property of the structure of inter-trial variability.

  3. Evoked emotions predict food choice.

    Directory of Open Access Journals (Sweden)

    Jelle R Dalenberg

    Full Text Available In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA and apply Multinomial Logit Models (MLM to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively. After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

  4. Alterations in Evoked Otoacoustic Emissions by the Use of Meglumine Antimoniate in American Tegumentary Leishmaniasis Patients (United States)

    de Oliveira Bezerra, Débora Cristina; Oliveira de Barcelos, Renata; Carvalho de Castro, Ellen; Jardim Duarte, Claudia Cristina; de Vasconcellos Carvalhaes Oliveira, Raquel; Salgado de Sousa Torraca, Tania; de Araújo-Melo, Maria Helena; Pereira Bom Braga, Frederico; Ramos Ferreira Terceiro, Benivaldo; do Nascimento Brahim Paes, Lúcia Regina; de Oliveira Schubach, Armando


    Introduction Tegumentary Leishmaniasis (TL) is a neglected, non-contagious, infectious disease, caused by different protozoa species of the Leishmania genus that affects skin and mucous membranes. Meglumine Antimoniate (MA), the first drug of choice for TL treatment in Brazil, has already been associated with cochlear toxicity, which is defined as damages of the cochlea caused by exposure to chemical substances, resulting in reversible or irreversible hearing loss. Auditory monitoring for cochlear toxicity aims at the early detection of auditory disorders, enabling, when possible, hearing to be preserved or an early auditory rehabilitation. Although otoacoustic emissions (OAEs) are used in this monitoring, there is no consensus on the criteria that define cochlear toxicity by this examination. The objective of this study was to describe the characteristics of the OAEs in cochlear toxicity monitoring in TL patients using MA. Methods Prospective and longitudinal study of auditory monitoring of 35 patients with parasitological diagnosis of TL, with liminal tonal audiometry, high frequency audiometry, immitanciometry, distortion product evoked otoacoustic emissions (DPEOAEs) and transient evoked otoacoustic emissions (TEOAEs) before treatment, at the end of treatment, one month after the end of treatment and two months after the end of treatment. Results 80% male, with median age of 44 years (IIQ: 22–59). In the pre-treatment evaluation: 11.4% complained of hearing loss and 20% of tinnitus, 48.6% presented auditory alterations in liminal tonal audiometry (LTA, 65.2% in high frequency audiometry (HFA), 26.6% in DPEOAE and 51.4% in TEOAE. No association was verified between genre and alterations in the EOAE examinations. We observed that patients that presented disorders in DPEOAE examinations were 17 years older than those without alterations and that patients that showed disorders in TEOAEO examinations were 34 years older than those without disorders. The presence

  5. Line scanning fMRI reveals earlier onset of optogenetically evoked BOLD response in rat somatosensory cortex as compared to sensory stimulation. (United States)

    Albers, Franziska; Schmid, Florian; Wachsmuth, Lydia; Faber, Cornelius


    The combination of optogenetic control and fMRI readout in the brain is increasingly used to assess neuronal networks and underlying signal processing. However, how exactly optogenetic activation or inhibition reproduces normal physiological input has not been fully unraveled. To assess details of temporal dynamics of the hemodynamic response, temporal resolution in rodent fMRI is often not sufficient. Recent advances in human fMRI using faster acquisition schemes cannot be easily translated to small animals due to smaller dimensions, fast physiological motion, and higher sensitivity to artefacts. Here, we applied a one dimensional line scanning acquisition with 50ms temporal resolution in rat somatosensory cortex. We observed that optogenetic activation reproduces the hemodynamic response upon sensory stimulation, but shows a 160 to 340ms earlier onset of the response. This difference is explained by direct activation of all opsin-expressing and illuminated cortical layers, while hemodynamic response to sensory stimulation is delayed during intracortical transmission between cortical layers. Our results confirm that optogenetic activation is a valid model for physiological neuronal input, and that differences in temporal behavior of only a few hundred milliseconds can be resolved in rodent fMRI.

  6. Chronic combined stress induces selective and long-lasting inflammatory response evoked by changes in corticosterone accumulation and signaling in rat hippocampus. (United States)

    Piskunov, Aleksey; Stepanichev, Mikhail; Tishkina, Anna; Novikova, Margarita; Levshina, Irina; Gulyaeva, Natalia


    Hippocampus is believed to be selectively vulnerable to stress. We hypothesized that this phenomenon may be mediated by relatively high vulnerability to neuroinflammation related to impairments of local glucocorticoid metabolism and signaling. We have evaluated inflammatory responses induced by acute or chronic combined stress in the cerebral cortex and hippocampus as well as circulating and brain corticosterone (CS) levels as well as expression of corticosterone target genes. The hippocampus showed higher stress-induced expression of the proinflammatory cytokine IL-1β as compared to the cerebral cortex. A month after the termination of the chronic stress, IL-1β mRNA in the cerebral cortex reached control level, while in the hippocampus it remained significantly increased. Under chronic stress, the maladaptive inflammatory response in hippocampus was accompanied by a significant increase in local CS levels, as compared to cerebral cortex. Under acute stress, the increased CS level induced changes in CS-regulated genes expression (CRF and IGF1), while this phenomenon was not observed after chronic stress. Thus, the hippocampus appears to be more vulnerable to stress-induced inflammation as compared to the neocortex and demonstrates persistent inflammatory response induced by chronic stress. Stress-induced maladaptive inflammatory response is associated with a selective increase in hippocampal CS accumulation and changes in CS signaling.

  7. [Evoked potentials and inhalation anesthetics]. (United States)

    Thiel, A; Russ, W; Hempelmann, G


    Intraoperative monitoring of evoked potentials can be affected by various factors including volatile anaesthetics. These effects have to be considered in order to give correct interpretations of the obtained data. Visual evoked potentials (VEP) and auditory evoked potentials (AEP) will show strong alterations under general anaesthesia whereas brainstem auditory evoked potentials (BAEP) are slightly affected. The effects of nitrous oxide, halothane, enflurane, and isoflurane on somatosensory evoked potentials (SEP) after median nerve stimulation were studied in 35 healthy adult patients. pCO2 and tympanic membrane temperature were held constant. Simultaneous cervical and cortical SEP recording was performed using surface electrodes. After induction of anaesthesia SEP were recorded during normoventilation with 100% oxygen and after inhalation of 66.6% nitrous oxide. 10 patients received halothane at inspired concentrations of 0.5, 1.0, 1.5, and 2.0%. After nitrous oxide had been replaced by oxygen, halothane was reduced in steps of 0.5%. SEP were recorded at the end of each period (15 min). Equipotent doses of enflurane or isoflurane were administered to 15 and 10 patients, respectively. Nitrous oxide depressed early cortical SEP amplitude. Halothane, enflurane, and isoflurane caused dose dependent increases of latencies. Reduction of amplitude was most pronounced with isoflurane. Using high doses of enflurane in oxygen cortical SEP showed unusual high amplitudes associated with marked increases of latencies. Even under high concentrations of volatile anaesthetics cervical SEP were minimally affected. The effects of anaesthetic gases have to be considered when SEP are recorded intraoperatively.

  8. Origin of acoustically evoked short latency negative response in guinea pigs%豚鼠声诱发短潜伏期负电位的来源初探

    Institute of Scientific and Technical Information of China (English)

    黄文钦; 覃焕桦; 农东晓; 唐安洲; 李治美; 杨甜


    Objective To establish a model of acoustically evoked short latency negative response (ASNR) in guinea pigs, a model of profound hearing loss with normal saccular functions, and verify the correlation between ASNR and vestibular evoked myogenic potential (VEMP). Methods Thirty-two healthy guinea pigs were employed in the experiment, which were randomly divided into control group ( 16subjects) and deafened group (16 subjects). Each animal experienced auditory and vestibular tests including auditory brainstem response ( ABR), VEMP and caloric test. A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by a jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later. The animals were received ABR, VEMP and caloric test 7 - 10 days following the drug administration. The deafened group was further divided into ASNR group and non-ASNR group, based on the presence of ASNR. Results In deafened group, five subjects died postoperatively, 11 subjects (22 ears) provided full data, ASNR was elicited in eight ears (36.4%), the threshold was 120- 130 dB SPL with mean of (124.4 ±4.96) dB SPL. Its latency range was 1.75 - 2. 60 ms with mean of ( 2. 15 ± 0. 27 ) ms. The mean latency of threshold was (2. 34 ±0. 18) ms. All eight ASNR ears presented with VEMP. The VEMP threshold, positive and negative potential latencies proved no statistical difference (P > 0. 05 ) between ASNR group and control group.Significant difference was detected between the VEMP presence of ASNR group and non-ASNR group ( P =0. 002). There was no statistically significant correlation between VEMP and caloric test neither between ASNR and caloric test in deafened group. Conclusions This study evoked ASNR in an ototoxicity guinea pig model which has profound hearing loss with normal saccular functions. The presence of ASNR correlated with VEMP, however, not correlated with caloric test, suggesting that ASNR

  9. Prediction of Long-Term Treatment Response to Selective Serotonin Reuptake Inhibitors (SSRIs Using Scalp and Source Loudness Dependence of Auditory Evoked Potentials (LDAEP Analysis in Patients with Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Bun-Hee Lee


    Full Text Available Background: Animal and clinical studies have demonstrated that the loudness dependence of auditory evoked potentials (LDAEP is inversely related to central serotonergic activity, with a high LDAEP reflecting weak serotonergic neurotransmission and vice versa, though the findings in humans have been less consistent. In addition, a high pretreatment LDAEP appears to predict a favorable response to antidepressant treatments that augment the actions of serotonin. The aim of this study was to test whether the baseline LDAEP is correlated with response to long-term maintenance treatment in patients with major depressive disorder (MDD. Methods: Scalp N1, P2 and N1/P2 LDAEP and standardized low resolution brain electromagnetic tomography-localized N1, P2, and N1/P2 LDAEP were evaluated in 41 MDD patients before and after they received antidepressant treatment (escitalopram (n = 32, 10.0 ± 4.0 mg/day, sertraline (n = 7, 78.6 ± 26.7 mg/day, and paroxetine controlled-release formulation (n = 2, 18.8 ± 8.8 mg/day for more than 12 weeks. A treatment response was defined as a reduction in the Beck Depression Inventory (BDI score of >50% between baseline and follow-up. Results: The responders had higher baseline scalp P2 and N1/P2 LDAEP than nonresponders (p = 0.017; p = 0.036. In addition, changes in total BDI score between baseline and follow-up were larger in subjects with a high baseline N1/P2 LDAEP than those with a low baseline N1/P2 LDAEP (p = 0.009. There were significantly more responders in the high-LDAEP group than in the low-LDAEP group (p = 0.041. Conclusions: The findings of this study reveal that a high baseline LDAEP is associated with a clinical response to long-term antidepressant treatment.

  10. Operant Audiometry Manual for Difficult-to-Test Children. Institute on Mental Retardation and Intellectual Development; Papers and Reports, Volume V, Number 19. (United States)

    Bricker, Diane D.; And Others

    To facilitate the use of operant audiometry with low functioning children (psychotic, severely retarded, or multiply handicapped), a procedures manual was developed containing definitions of terms, instructions for determining reinforcers, physical facilities and equipment needs, diagrams, component lists, and technical descriptions. Development…

  11. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill;


    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...... in different occipital and extraoccipital cortical areas not explained by the boxcar regressor. The results suggest that the P1-N2 regressor is the best EEG-based regressor to model the visual paradigm, but when looking for additional effects like habituation or attention modulation that cannot be modeled...

  12. Neural processing of acoustic duration and phonological German vowel length: time courses of evoked fields in response to speech and nonspeech signals. (United States)

    Tomaschek, Fabian; Truckenbrodt, Hubert; Hertrich, Ingo


    Recent experiments showed that the perception of vowel length by German listeners exhibits the characteristics of categorical perception. The present study sought to find the neural activity reflecting categorical vowel length and the short-long boundary by examining the processing of non-contrastive durations and categorical length using MEG. Using disyllabic words with varying /a/-durations and temporally-matched nonspeech stimuli, we found that each syllable elicited an M50/M100-complex. The M50-amplitude to the second syllable varied along the durational continuum, possibly reflecting the mapping of duration onto a rhythm representation. Categorical length was reflected by an additional response elicited when vowel duration exceeded the short-long boundary. This was interpreted to reflect the integration of an additional timing unit for long in contrast to short vowels. Unlike to speech, responses to short nonspeech durations lacked a M100 to the first and M50 to the second syllable, indicating different integration windows for speech and nonspeech signals.

  13. Long-term potentiation of evoked presynaptic response at CA3-CA1 synapses by transient oxygen-glucose deprivation in rat brain slices. (United States)

    Ai, Jinglu; Baker, Andrew


    Physiological activity-dependent long-term changes in synaptic transmission, as long-term potentiation (LTP) are thought to be the substrate of learning and memory. However, a form of postsynaptic pathological LTP at the CA3-CA1 synapses has been demonstrated following few minutes of anoxia and aglycemia in vitro. The ischemia LTP shared many molecular mechanisms with the physiological LTP, and was believed to be involved in the delayed neuronal death following ischemia. However, the role of the presynaptic component in this regard is not known. Here we show that a short period of oxygen-glucose deprivation can induce a form of LTP (lasting for hours) of the presynaptic response at the CA3-CA1 synapses. This form of LTP is independent of postsynaptic alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors, but Ca(2+) dependent. This presynaptic LTP may represent a presynaptic hyperexcitability of the afferent fibers following ischemia, and responsible for the excitotoxicity to the CA1 neurons (ischemia-induced increases of glutamate release that kills neurons) and the postsynaptic pathological ischemic LTP.

  14. Gating of the vertex somatosensory and auditory evoked potential P50 and the correlation to skin conductance orienting response in healthy men

    DEFF Research Database (Denmark)

    Arnfred, S M; Eder, D N; Hemmingsen, R P


    to the skin conductance orienting response (SCOR) in 20 healthy men. We measured mid-latency vertex components (SEP: P50, N65, P85 and N100; AEP: P30, N45, P50 and N80). The gating was most pronounced at ISI 500 ms where the SEP P50 and N100 gating were 0.59 and 0.37, respectively, as compared to a gating...... of 0.61 in P30, 0.33 in P50 and 0.45 in N80 in the AEP. Repetition effects in the two modalities were not correlated. AEP P50 gating was correlated to skin conductance level (SCL). The combination of recording repetition effects on the mid-latency EP in two modalities could provide a method...

  15. Evoked Emotions Predict Food Choice

    NARCIS (Netherlands)

    Dalenberg, J.R.; Gutjar, S.; Horst, ter G.J.; Graaf, de C.; Renken, R.; Jager, G.


    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Th

  16. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seok Kyun; Kim, Gwang Won; Kang, Heoung Keun; Jeong, Gwang Woo [Chonnam National University, Gwangju (Korea, Republic of); Yang, Jong Chul [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Seok Kwun [Dong-A University College of Medicine, Busan (Korea, Republic of)


    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  17. Chronic exposure to broadband noise at moderate sound pressure levels spatially shifts tone-evoked responses in the rat auditory midbrain. (United States)

    Lau, Condon; Pienkowski, Martin; Zhang, Jevin W; McPherson, Bradley; Wu, Ed X


    Noise-induced hearing disorders are a significant public health concern. One cause of such disorders is exposure to high sound pressure levels (SPLs) above 85 dBA for eight hours/day. High SPL exposures occur in occupational and recreational settings and affect a substantial proportion of the population. However, an even larger proportion is exposed to more moderate SPLs for longer durations. Therefore, there is significant need to better understand the impact of chronic, moderate SPL exposures on auditory processing, especially in the absence of hearing loss. In this study, we applied functional magnetic resonance imaging (fMRI) with tonal acoustic stimulation on an established broadband rat exposure model (65 dB SPL, 30 kHz low-pass, 60 days). The auditory midbrain response of exposed subjects to 7 kHz stimulation (within exposure bandwidth) shifts dorsolaterally to regions that typically respond to lower stimulation frequencies. This shift is quantified by a region of interest analysis that shows that fMRI signals are higher in the dorsolateral midbrain of exposed subjects and in the ventromedial midbrain of control subjects (pmidbrain regions above the exposure bandwidth spatially expand due to exposure. This expansion shifts lower frequency regions dorsolaterally. Similar observations have previously been made in the rat auditory cortex. Therefore, moderate SPL exposures affect auditory processing at multiple levels, from the auditory cortex to the midbrain.

  18. In vivo optical microprobe imaging for intracellular Ca2+ dynamics in response to dopaminergic signaling in deep brain evoked by cocaine (United States)

    Luo, Zhongchi; Pan, Yingtian; Du, Congwu


    Ca2+ plays a vital role as second messenger in signal transduction and the intracellular Ca2+ ([Ca2+]i) change is an important indicator of neuronal activity in the brain, including both cortical and subcortical brain regions. Due to the highly scattering and absorption of brain tissue, it is challenging to optically access the deep brain regions (e.g., striatum at >3mm under the brain surface) and image [Ca2+]i changes with cellular resolutions. Here, we present two micro-probe approaches (i.e., microlens, and micro-prism) integrated with a fluorescence microscope modified to permit imaging of neuronal [Ca2+]i signaling in the striatum using a calcium indicator Rhod2(AM). While a micro-prism probe provides a larger field of view to image neuronal network from cortex to striatum, a microlens probe enables us to track [Ca2+]i dynamic change in individual neurons within the brain. Both techniques are validated by imaging neuronal [Ca2+]i changes in transgenic mice with dopamine receptors (D1R, D2R) expressing EGFP. Our results show that micro-prism images can map the distribution of D1R- and D2R-expressing neurons in various brain regions and characterize their different mean [Ca2+]i changes induced by an intervention (e.g., cocaine administration, 8mg/kg., i.p). In addition, microlens images can characterize the different [Ca2+]i dynamics of D1 and D2 neurons in response to cocaine, including new mechanisms of these two types of neurons in striatum. These findings highlight the power of the optical micro-probe imaging for dissecting the complex cellular and molecular insights of cocaine in vivo.

  19. On the use of click-evoked electric brainstem responses in audiological diagnosis. IV. Interaural latency differences (wave V) in cochlear hearing loss. (United States)

    Rosenhamer, H J; Lindström, B; Lundborg, T


    Interaural latency differences (ILDs) of wave V of the brainstem electric response (BSER) were studied (1) in 20 normal-hearing subjects at 90, 80, 60 and 40 dB HL click level, (2) in 22 patients with symmetrical cochlear hearing loss at 90 dB HL, corresponding to 45-80 dB SL, and (3) in 45 patients with asymetrical cochlear hearing loss with interaural recruitment, at 90 dB HL on one hand and at a click sensation level corresponding to 90 dB HL in the poorer ear (range 10-75 dB SL) on the other hand. In the normal hearing group the ILDs did not exceed 0.2 ms except in one case at 40 dB HL (0.3 ms). In the symmetrical cochlear loss group the ILD did not exceed 0.2 ms in any patient. In the asymmetrical cochlear loss group the ILD at 90 dB HL exceeded 0.2 ms in 12 cases, but only in four cases after correction for pure tone hearing loss at 4 kHz by 0.1 for each 10 dB above 50 dB HL; at equal sensation levels the ILDs were all zero or negative meaning that the wave V latency was shorter on stimulation of the poorer ear. Assuming ILD to be a valid discriminator between cochlear and retrocochlear lesions, the corrected ILD at equal click hearing levels (90 dB HL), with the critical value set at 0.2 ms, thus gave a 9% false-positive rate whereas the ILS at equal sensation levels, with the critical value set at zero, gave no false-positives. It still remains to be shown that the latter criterion will not increase the number of false-negative results in retrocochlear lesions.

  20. Early visually evoked electrophysiological responses over the human brain (P1, N170 show stable patterns of face-sensitivity from 4 years to adulthood

    Directory of Open Access Journals (Sweden)

    Dana Kuefner


    Full Text Available Whether the development of face recognition abilities truly reflects changes in how faces, specifically, are perceived, or rather can be attributed to more general perceptual or cognitive development is debated. Event-related potential (ERP recordings on the scalp offer promise for this issue because they allow brain responses to complex visual stimuli to be relatively well isolated from other sensory, cognitive and motor processes. ERP studies in 5-16 year-old children report large age-related changes in amplitude, latency (decreases and topographical distribution of the early visual components, the P1 and the occipito-temporal N170. To test the face specificity of these effects, we recorded high-density ERPs to pictures of faces, cars, and their phase-scrambled versions from 72 children between the ages of 4 and 17, and a group of adults. We found that none of the previously reported age-dependent changes in amplitude, latency or topography of the P1 or N170 were specific to faces. Most importantly, when we controlled for age-related variations of the P1, the N170 appeared remarkably similar in amplitude and topography across development, with much smaller age-related decreases in latencies than previously reported. At all ages the N170 showed equivalent face-sensitivity: it had the same topography and right hemisphere dominance, it was absent for meaningless (scrambled stimuli, and larger and earlier for faces than cars. The data also illustrate the large amount of inter-individual and inter-trial variance in young children’s data, which causes the N170 to merge with a later component, the N250 in grand-averaged data. Based on our observations, we suggest that the previously reported “bi-fid” N170 of young children is in fact the N250. Overall, our data indicate that the electrophysiological markers of face-sensitive perceptual processes are present from 4 years of age and do not appear to change throughout development.

  1. Regarding the quantification of peripheral microcirculation--Comparing responses evoked in the in vivo human lower limb by postural changes, suprasystolic occlusion and oxygen breathing. (United States)

    Silva, Henrique; Ferreira, Hugo; Bujan, Ma Julia; Rodrigues, Luis Monteiro


    The human skin is an interesting model to explore microcirculation, particularly if using noninvasive technologies such as LDF (Laser Doppler Flowmetry) and tc (transcutaneous) gasimetry and methods as near as possible from the normal physiological state. In this study, we combined those technologies with three classical approaches--leg raising from supine, suprasystolic occlusion (in the ankle), and normobaric oxygen breathing to explore distal peripheral circulation in the foot. These methods are often cited, but a comparative assessment has not been done. The goal of this study was to identify relevant flow related descriptors, method-related advantages and pitfalls, and eventually, to find the best experimental approach. Volunteers (both genders, 22.1 ± 3.7 years old) were subjected to these methods and variables registered during basal, challenge and stabilization phases. Descriptive and comparative statistics were obtained, adopting a 95% confidence level. All flow-related quantitative descriptors potentially useful for the analysis were identified and compared. As expected, male patients consistently showed higher LDF levels and transepidermal water loss (TEWL) and lower tcpO2 values. However, lower results were recorded in the supine position, suggesting a postural dependence. Both leg raising and suprasystolic occlusion produced a hyperemic response after provocation, although different in magnitude, significantly reducing LDF and tcpO2 during provocation. The oxygen breathing method provided the most patient-friendly protocol, consistently reducing LDF (potentially by the inhibition of production of local vasodilators). TEWL increased during the provocation phase in all protocols, although not significantly. Baseline tcpO2 was found to correlate positively with the peak tcpO2 during oxygen breathing and basal LDF with peak flow during leg raising and suprasystolic occlusion. No statistical correlation between TEWL and LDF could be demonstrated under the

  2. Auditory evoked potentials in postconcussive syndrome. (United States)

    Drake, M E; Weate, S J; Newell, S A


    The neuropsychiatric sequelae of minor head trauma have been the source of controversy. Most clinical and imaging studies have shown no alteration after concussion, but neuropsychological and neuropathological abnormalities have been reported. Some changes in neurophysiologic diagnostic tests have been described in postconcussive syndrome. We recorded middle latency auditory evoked potentials (MLR) and slow vertex responses (SVR) in 20 individuals with prolonged cognitive difficulties, behavior changes, dizziness, and headache after concussion. MLR is utilized alternating polarity clicks presented monaurally at 70 dB SL at 4 per second, with 40 dB contralateral masking. Five hundred responses were recorded and replicated from Cz-A1 and Cz-A2, with 50 ms. analysis time and 20-1000 Hz filter band pass. SVRs were recorded with the same montage, but used rarefaction clicks, 0.5 Hz stimulus rate, 500 ms. analysis time, and 1-50 Hz filter band pass. Na and Pa MLR components were reduced in amplitude in postconcussion patients. Pa latency was significantly longer in patients than in controls. SVR amplitudes were longer in concussed individuals, but differences in latency and amplitude were not significant. These changes may reflect posttraumatic disturbance in presumed subcortical MLR generators, or in frontal or temporal cortical structures that modulate them. Middle and long-latency auditory evoked potentials may be helpful in the evaluation of postconcussive neuropsychiatric symptoms.

  3. Audiometria de alta freqüência em adultos jovens e mais velhos quando a audiometria convencional é normal High-frequency audiometry in young and older adults when conventional audiometry is normal

    Directory of Open Access Journals (Sweden)

    Isabella Monteiro de Castro Silva


    Full Text Available A audiometria de alta freqüência é capaz de detectar precocemente alterações em sensibilidade advindas de processos como o envelhecimento. Seu uso é limitado, o que recomenda estudos para esclarecer seu desempenho, especialmente entre adultos de mais idade. OBJETIVO: Comparar os limiares para as freqüências de 250Hz a 16kHz, entre adultos jovens e mais velhos normoacúsicos, com e sem queixa audiológica. CASUÍSTICA E MÉTODO: A sensibilidade a tons puros de 250Hz a 16kHz foi avaliada com audiômetro AC-40, em 64 adultos, igualmente distribuídos: jovens (25 a 35 anos e mais velhos (45 a 55 anos de ambos os gêneros, com forma de estudo de coorte transversal. RESULTADOS: Os adultos mais velhos apresentaram limiares mais elevados em todas as freqüências, mais significativamente nas mais altas (8 a 16kHz, quando comparados com os adultos jovens. Homens apresentaram limiares mais elevados do que mulheres entre 3 e 10kHz. CONCLUSÃO: O processo de envelhecimento auditivo, envolvendo perda de sensibilidade auditiva para altas freqüências, pode ser detectado em idades anteriores às tipicamente pesquisadas, uma vez que a audiometria de alta freqüência demonstrou ser instrumento importante para distinguir a sensibilidade auditiva entre adultos jovens e mais velhos, quando audiologicamente normais.High-frequency audiometry can detect early changes in auditory sensitivity resulting from processes such as aging. Nonetheless its use is still limited, and additional studies are required to establish its use, particularly among older adults. AIM: To compare pure tone thresholds for frequencies from 250 Hz to 16 kHz in young and older adults, with or without audiologic complaints. METHOD: Pure tone sensitivity to 250 Hz to 16 kHz was assessed with an AC-40 audiometer in 64 adults, evenly distributed in young (25 to 35 years-old and older (45 to 55 years-old adults of both sexes. This is a cross-sectional study. RESULTS: Although all

  4. The paradox of music-evoked sadness: an online survey. (United States)

    Taruffi, Liila; Koelsch, Stefan


    This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

  5. The paradox of music-evoked sadness: an online survey.

    Directory of Open Access Journals (Sweden)

    Liila Taruffi

    Full Text Available This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772. The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

  6. Type-2 diabetes mellitus and auditory brainstem response

    Directory of Open Access Journals (Sweden)

    Sheelu S Siddiqi


    Full Text Available Objective: Diabetes mellitus (DM causes pathophysiological changes at multiple organ system. With evoked potential techniques, the brain stem auditory response represents a simple procedure to detect both acoustic nerve and central nervous system pathway damage. The objective was to find the evidence of central neuropathy in diabetes patients by analyzing brainstem audiometry electric response obtained by auditory evoked potentials, quantify the characteristic of auditory brain response in long standing diabetes and to study the utility of auditory evoked potential in detecting the type, site, and nature of lesions. Design: A total of 25 Type-2 DM [13 (52% males and 12 (48% females] with duration of diabetes over 5 years and aged over 30 years. The brainstem evoked response audiometry (BERA was performed by universal smart box manual version 2.0 at 70, 80, and 90 dB. The wave latency pattern and interpeak latencies were estimated. This was compared with 25 healthy controls (17 [68%] males and 8 [32%] females. Result: In Type-2 DM, BERA study revealed that wave-III representing superior olivary complex at 80 dB had wave latency of (3.99 ± 0.24 ms P < 0.001, at 90 dB (3.92 ± 0.28 ms P < 0.001 compared with control. The latency of wave III was delayed by 0.39, 0.42, and 0.42 ms at 70, 80, and 90 dB, respectively. The absolute latency of wave V representing inferior colliculus at 70 dB (6.05 ± 0.27 ms P < 0.001, at 80 dB (5.98 ± 0.27 P < 0.001, and at 90 dB (6.02 ± 0.30 ms P < 0.002 compared with control. The latency of wave-V was delayed by 0.48, 0.47, and 0.50 ms at 70, 80, and 90 dB, respectively. Interlatencies I-III at 70 dB (2.33 ± 0.22 ms P < 0.001, at 80 dB (2.39 ± 0.26 ms P < 0.001, while at 90 dB (2.47 ± 0.25 ms P < 0.001 when compared with control. Interlatencies I-V at 70 dB (4.45 ± 0.29 ms P < 0.001 at 80 dB (4.39 ± 0.34 ms P < 0.001, and at 90 dB (4.57 ± 0.31 ms P < 0.001 compared with control. Out of 25 Type-2 DM, 13 (52

  7. Achieving Presence through Evoked Reality. (United States)

    Pillai, Jayesh S; Schmidt, Colin; Richir, Simon


    The sense of "Presence" (evolving from "telepresence") has always been associated with virtual reality research and is still an exceptionally mystifying constituent. Now the study of presence clearly spans over various disciplines associated with cognition. This paper attempts to put forth a concept that argues that it's an experience of an "Evoked Reality (ER)" (illusion of reality) that triggers an "Evoked Presence (EP)" (sense of presence) in our minds. A Three Pole Reality Model is proposed to explain this phenomenon. The poles range from Dream Reality to Simulated Reality with Primary (Physical) Reality at the center. To demonstrate the relationship between ER and EP, a Reality-Presence Map is developed. We believe that this concept of ER and the proposed model may have significant applications in the study of presence, and in exploring the possibilities of not just virtual reality but also what we call "reality."

  8. Time Perception and Evoked Potentials (United States)


    ARI Research Note 88-69 0 MitnS.Ktohe U.0 ... Ann-r (. Time Perception and Evoked Potentials Paul FraisseDT ( Lfniversit6 Rene Descartes E LECTE...JOHNSON 00L, [N Technical Dicctojr Cmad Research accomplished under contract for the Department of the Army C. Universite Rene Descartes , Paris )r...ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK Labrato-ire de Psychologie Experimental AREA• WORK UNIT NUMBERS Universite Rene Descartes

  9. Dynamic Posturography of Injured Lower Limb in Postural Evoked Response%下肢损伤者姿势诱发反射下的动态姿势图分析

    Institute of Scientific and Technical Information of China (English)

    程冬梅; 邵黎明; 范利华; 陈芳; 孙婧


    目的:利用动态姿势图分析下肢损伤者的平衡功能。方法利用动态姿势图测试仪对62例正常人和258例下肢骨关节损伤者进行姿势诱发反射检测,包括感觉整合测试、适应性测试,将两组实验对象的检测结果进行t检验。结果与正常人相比,下肢损伤者动态姿势图中的感觉整合测试平衡分(SOT3~SOT6)及动态本体感觉比例分差异有统计学意义(P<0.05),适应性测试无明显下降趋势。结论下肢损伤可导致平衡功能降低。%Objective To analyze the balance function of injured lower lim b by dynam ic posturography. Methods Using the dynam ic posturography instrum ent, the postural evoked responses of sixty-two norm al people and two hundred and fifty-eight people with injured lower lim b bones and joints were detected. The test was included sensory organization test(SO T) and adaption test(ADT).The results of two groups were com pared by t test. Results Com pared with the norm al people, the im paired people had significant statistical differences in balance scores of SO T3-SO T6 and proportion score of dynam ic proprioception (P<0.05). There was no obvious decrease in ADT. Conclusion The balance function of injured lower lim b significantly decreases.

  10. Exploring the Mechanisms of Exercise-Induced Hypoalgesia Using Somatosensory and Laser Evoked Potentials. (United States)

    Jones, Matthew D; Taylor, Janet L; Booth, John; Barry, Benjamin K


    Exercise-induced hypoalgesia is well described, but the underlying mechanisms are unclear. The aim of this study was to examine the effect of exercise on somatosensory evoked potentials, laser evoked potentials, pressure pain thresholds and heat pain thresholds. These were recorded before and after 3-min of isometric elbow flexion exercise at 40% of the participant's maximal voluntary force, or an equivalent period of rest. Exercise-induced hypoalgesia was confirmed in two experiments (Experiment 1-SEPs; Experiment 2-LEPs) by increased pressure pain thresholds at biceps brachii (24.3 and 20.6% increase in Experiment 1 and 2, respectively; both d > 0.84 and p 0.57 and p evoked potentials (14.6% decrease, d = -0.42, p = 0.004) and somatosensory evoked potentials (10.9% increase, d = -0.02, p = 1) were also observed, while an equivalent period of rest showed similar habituation (laser evoked potential: 7.3% decrease, d = -0.25, p = 0.14; somatosensory evoked potential: 20.7% decrease, d = -0.32, p = 0.006). The differential response of pressure pain thresholds and heat pain thresholds to exercise is consistent with relative insensitivity of thermal nociception to the acute hypoalgesic effects of exercise. Conflicting effects of exercise on somatosensory evoked potentials and laser evoked potentials were observed. This may reflect non-nociceptive contributions to the somatosensory evoked potential, but could also indicate that peripheral nociceptors contribute to exercise-induced hypoalgesia.

  11. The Frequency of Hearing Loss and Hearing Aid Prescription in the Clients of the Avesina Education and Health Center, Audiometry Clinic, 1377

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    Abbas Bastani


    Full Text Available Objective: Determining the frequency of hearing disorders and hearing aid using in the clients referring to the Avesina education and health center, audiometry clinic, 1377. Method and Material: This is an assesive-descriptive survey that conducted on more than 2053 (1234 males and 819 females who referred for audiometry after examination by a physician. Case history, otoscopy, PTA, speech and immittance audiometry were conducted for all the clients. The findings were expressed in tables and diagrams of frequency. The age and sex relationship. All types of hearing losses and the number of the hearing-impaired clients need a hearing aid were assessed. Findings: 56% of this population were hearing-impaired and 44% had normal hearing were hearing. 60% were males and 40% females. Of the hearing-impaired, 44% had SNHL, 35.6% CHL and 8.2% mixed hearing loss. The hearing aid was prescribed for 204 (83 females and121 males if they need that only 20 females and 32 males wear it. Conclusion: It this sample, SNHL is of higher frequency. According to this survey, the more the age, the more the hearing aid is accepted (85% of wearer are more than 49 the prevalence of the hearing impaired males are more than females (60% versus 40%. Only 25% of the hearing-impaired wear hearing aids.

  12. Short latency vestibular evoked potentials in the chicken embryo (United States)

    Jones, S. M.; Jones, T. A.


    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  13. [Evoked potentials in intracranial operations: current status and our experiences]. (United States)

    Nau, H E; Hess, W; Pohlen, G; Marggraf, G; Rimpel, J


    Intraoperative neuromonitoring, especially evoked potential monitoring, has gained interest in recent years for both the anesthesiologist evaluating cerebral function and the neurosurgeon wishing to avoid neuronal lesions during intracranial operations. Before evoked potential monitoring can be introduced as a routine method of intraoperative management, experience with this method particularly in intensive care units, is imperative. We recorded evoked potentials with the Compact Four (Nicolet) and Basis 8000 (Schwarzer Picker International) computer systems. Preoperative derivations should be done with the same apparatus used intraoperatively and parameters of peri- and intraoperative derivations should not be changed. The patient's head must be fixed in a Mayfield clamp in order to avoid artefacts during trepanation. The possible artefacts due to apparatus, patient, or anesthesia are summarized in the tables. The derivations of evoked potentials should be supervised by a person who is not involved in the anesthesia or the surgical procedure; this condition may change in the future with full automatization of the recording technique and alarms. Good communication between surgeon, anesthesiologist, and neurophysiological assistant is a prerequisite. The modality is chosen in accordance with the affected neuronal system: visual-evoked potential (VEP) monitoring in the management of processes affecting the visual pathway, brain stem auditory-(BAER) and somatosensory-evoked potential (SSEP) monitoring in lesions affecting these pathways, in particular space-occupying lesions of the posterior fossa. VEP monitoring may be useful, but we observed alterations of the responses without changes in the level of anesthesia or manipulation of the visual pathways. In space-occupying processes of the cerebellopontine angle, BAER could not be developed in nearly all cases because the large underlying tumor had caused the disappearance of waves II-V. In these cases SSEP monitoring

  14. An investigation on binocular summation response of visual evoked potential in children with hyperopia amblyopia%弱视儿童双眼总和视觉诱发电位变化的研究

    Institute of Scientific and Technical Information of China (English)

    于春红; 廖瑜俊; 杨洋; 邓燕; 彭小维; 鄢涛; 殷小龙


    Objective Conventional examination for vision function adopts subjective psychophysics methods.Pattern visual evoked potential (P-VEP) binocular summation response is a new objective way for the test of vision function.But its clinical value in evaluating vision function of amblyopia children is still in controversy.This study was to explore the binocular vision and the feature of P-VEP binocular summation in children with amblyopia and evaluate the significance of P-VEP binocular summation in binocular vision.MethodsThis is a case-controlled study.P-VEP binocular summation response and single ocular P-VEP response was respectively recorded in 151 hyperopia amblyopia children and 80 age- and gender-matched normal children.P-VEP response from children with hyperopia amblyopia was recorded under the corrected vision.The hyperopia amblyopia was diagnosed based on the standard of National Children Amblyopia and Strabismus Prevention and Treatment Working Group.The feature of P-VEP binocular summation was further analyzed and compared with monocular VEP response.Informed consent was obtained from each subject or custodian prior to the trail.ResultsNo significant difference was found in latency between P-VEP binocular summation response and monocular P-VEP response whether amblyopia children or normal children(P>0.05).Binocular response/monocular response value in amblyopia children was lower than that in normal children(P<0.05).Binocular response/monocular response value in mild or moderate amblyopia children was higher than that in severe amblyopia children(P<0.05).Binocular response/monocular response value was significantly reduced in the children with binocular vision than in the children without binocular vision (P<0.05).ConclusionP-VEP binocular vision,acting as an evaluation factor,could impartially reflect the function of binocular vision of amblyopia children.%目的 探讨弱视儿童双眼视功能及总和图形视觉诱发电位(P-VEP)反应的特

  15. Os efeitos da polaridade do estímulo nos Potenciais Evocados Auditivos de Tronco Encefálico Polarity stimulation effects on brainstem auditory evoked potentials

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    Janaina Patricio de Lima


    Full Text Available Os Potenciais Evocados Auditivos de Tronco Encefálico (PEATE são considerados potenciais exógenos, ou seja, as respostas obtidas são altamente dependentes da característica do estímulo utilizado para evocá-los. OBJETIVO: Averiguar a influência da polaridade do estímulo clique na pesquisa dos PEATE em diferentes intensidades, utilizando-se fone de inserção. FORMA DE ESTUDO: Clínico. MATERIAL E MÉTODO: 33 indivíduos, idade entre 18 e 28 anos, sem alteração auditiva foram submetidos à pesquisa dos PEATE, com estímulo clique nas polaridades de rarefação, condensação e alternada, em diferentes intensidades. RESULTADOS: As latências absolutas da onda V mostraram-se menores na polaridade de rarefação quando comparadas às demais e na intensidade de 80 dBnHL houve diferença significante entre a rarefação e as demais polaridades para as latências interpicos III-V e I-V. Houve alta correlação entre as polaridades de condensação e alternada para as latências absolutas e interpicos na intensidade de 80 dBnHL. CONCLUSÃO: A polaridade do estímulo clique influência significativamente nos PEATE. Na rotina em que se utiliza o fone TDH 39, com apresentação de polaridade alternada, sugere-se que o uso da polaridade de condensação seja mais adequado para efeitos de comparação padronizada, devido à maior semelhança das latências encontradas nesse estudo com fone de inserção.Brainstem Auditory Evoked Potentials are considered exogenous potentials, that is, the responses obtained are highly dependent upon the characteristic of the stimulus used to evoke them. AIM: To investigate the influence of the click stimulus polarity in the study of Brainstem Evoked Response Audiometry (BERA at different intensities, using insertion-canal earphones. TYPE OF STUDY: Clinical. MATERIALS AND METHODS: 33 individuals, aged between 18 and 28, with no auditory alteration were submitted to BERA testing, with click stimulus on the

  16. Recording visual evoked potentials and auditory evoked P300 at 9.4T static magnetic field.

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    Jorge Arrubla

    Full Text Available Simultaneous recording of electroencephalography (EEG and functional magnetic resonance imaging (fMRI has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4 T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultra-high magnetic field due to the easy assessment of the visual cortex. Auditory evoked P300 measurements are of interest since it is believed that they represent the earliest stage of cognitive processing. In this study, we investigate the feasibility of recording visual evoked potentials and auditory evoked P300 in a 9.4 T static magnetic field. For this purpose, EEG data were recorded from 26 healthy volunteers inside a 9.4 T MR scanner using a 32-channel MR compatible EEG system. Visual stimulation and auditory oddball paradigm were presented in order to elicit evoked related potentials (ERP. Recordings made outside the scanner were performed using the same stimuli and EEG system for comparison purposes. We were able to retrieve visual P100 and auditory P300 evoked potentials at 9.4 T static magnetic field after correction of the ballistocardiogram artefact using independent component analysis. The latencies of the ERPs recorded at 9.4 T were not different from those recorded at 0 T. The amplitudes of ERPs were higher at 9.4 T when compared to recordings at 0 T. Nevertheless, it seems that the increased amplitudes of the ERPs are due to the effect of the ultra-high field on the EEG recording system rather than alteration in the intrinsic processes that generate the electrophysiological responses.

  17. Recording visual evoked potentials and auditory evoked P300 at 9.4T static magnetic field. (United States)

    Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N Jon


    Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4 T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultra-high magnetic field due to the easy assessment of the visual cortex. Auditory evoked P300 measurements are of interest since it is believed that they represent the earliest stage of cognitive processing. In this study, we investigate the feasibility of recording visual evoked potentials and auditory evoked P300 in a 9.4 T static magnetic field. For this purpose, EEG data were recorded from 26 healthy volunteers inside a 9.4 T MR scanner using a 32-channel MR compatible EEG system. Visual stimulation and auditory oddball paradigm were presented in order to elicit evoked related potentials (ERP). Recordings made outside the scanner were performed using the same stimuli and EEG system for comparison purposes. We were able to retrieve visual P100 and auditory P300 evoked potentials at 9.4 T static magnetic field after correction of the ballistocardiogram artefact using independent component analysis. The latencies of the ERPs recorded at 9.4 T were not different from those recorded at 0 T. The amplitudes of ERPs were higher at 9.4 T when compared to recordings at 0 T. Nevertheless, it seems that the increased amplitudes of the ERPs are due to the effect of the ultra-high field on the EEG recording system rather than alteration in the intrinsic processes that generate the electrophysiological responses.

  18. 正常听力豚鼠声诱发短潜伏期负电位的研究%The study of acoustically evoked short latency negative responses in normal guinea pigs

    Institute of Scientific and Technical Information of China (English)

    张少华; 陈瑾; 林晨希; 农东晓; 唐安洲


    目的 观察听力正常豚鼠通过掩蔽能否引出声诱发短潜伏期负电位(acoustically evoked short latency negative response,ASNR),并与药物致聋豚鼠的ASNR进行对比,同时验证二者的神经核团来源是否相同.方法 40只健康豚鼠采用随机数字表法分为三组:对照组8只(16耳)、掩蔽组16只(32耳)和致聋组16只(32耳).掩蔽组选择气导白噪声作为掩蔽声,采用15 dB的掩蔽/刺激强度差以避免掩蔽不足和掩蔽过度,根据ASNR引出与否,分为掩蔽ASNR组和掩蔽非ASNR组.致聋组采用卡那霉素和利尿酸联合致聋,根据ASNR引出与否,分为致聋ASNR组和致聋非ASNR组.全部豚鼠均行前庭神经核定位及直流电损毁,24 h后再次行听性脑干反应(ABR)/ASNR测试,比较损毁前后ABR/ASNR的改变情况.脑干切片显微镜下验证电解损毁部位.结果 掩蔽组32耳中24耳引出ASNR,致聋组26耳重度聋耳中12耳引出 ASNR,掩蔽组ASNR的引出率(75.0%)高于致聋组(46.2%),差异具有统计学意义(x2=5.07,P=0.024);两组引出的ASNR在阈值和潜伏期上差异均无统计学意义(P值均>0.05).正常对照组前庭神经核损毁后,ABR波形及引出率无明显改变.掩蔽ASNR组和致聋ASNR组引出耳前庭神经核损毁后,ASNR均消失.脑干切片显示电损毁前庭神经核部位均准确无误.结论 利用适当强度的白噪声掩蔽可以成功地在豚鼠听力正常耳引出 ASNR,其波形、阈值和潜伏期与药物致聋豚鼠重度听力损失耳引出的ASNR相同,二者均起源于前庭神经核.%Objective To compare acoustically evoked short latency negative responses (ASNR) elicited from normal and profound hearing loss guinea pig ears and to confirm their vestibular nuclei origination.Methods Forty healthy guinea pigs were employed in the experiment, which were randomly divided into the control group (8 subjects, 16 ears), the masking group (16 subjects, 32 ears) and the deafened group (16 subjects, 32

  19. Evoked potentials in immobilized cats to a combination of clicks with painful electrocutaneous stimuli (United States)

    Gilinskiy, M. A.; Korsakov, I. A.


    Averaged evoked potentials in the auditory, somatosensory, and motor cortical zones, as well as in the mesencephalic reticular formation were recorded in acute experiments on nonanesthetized, immobilized cats. Omission of the painful stimulus after a number of pairings resulted in the appearance of a delayed evoked potential, often resembling the late phases of the response to the painful stimulus. The characteristics of this response are discussed in comparison with conditioned changes of the sensory potential amplitudes.

  20. Potenciais Evocados Auditivos de Estado Estável no diagnóstico audiológico infantil: uma comparação com os Potenciais Evocados Auditivos de Tronco Encefálico Steady-state auditory evoked responses in audiological diagnosis in children: a comparison with brainstem evoked auditory responses

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    Gabriela Ribeiro Ivo Rodrigues


    Full Text Available Os Potenciais Evocados Auditivos de Estado Estável (PEAEE têm sido apontados como uma técnica promissora na avaliação audiológica infantil. OBJETIVO: Investigar o nível de concordância entre os resultados dos PEAEE e dos Potenciais Evocados Auditivos de Tronco Encefálico (PEATE-clique em um grupo de crianças com perda auditiva sensorioneural, averiguando assim a aplicabilidade clínica desta técnica na avaliação audiológica infantil. FORMA DE ESTUDO: Clínico prospectivo de coorte transversal. MATERIAL E MÉTODO: 15 crianças com idade entre dois e 36 meses e diagnóstico de perda auditiva sensorioneural. A concordância entre as respostas dos dois testes foi avaliada por meio do coeficiente de correlação intraclasse e o teste de McNemar comparou os dois testes quanto à probabilidade de ocorrência de resposta. RESULTADOS: Os coeficientes de correlação encontrados foram 0,70; 0,64; 0,49; 0,69; 0,63 e 0,68 respectivamente para as frequências de 1, 2, 4, 1-2, 2-4 e 1-2-4kHz. No teste de McNemar foi obtido p=0.000, indicando que a probabilidade de se obter resposta presente nos dois testes não é igual, sendo maior nos PEAEE. CONCLUSÃO: A boa concordância observada entre as técnicas sugere que um exame pode ser complementar ao outro. Os PEAEE, entretanto, promoveram informações adicionais nos casos de perdas severas e profundas, acrescentando dados importantes para a reabilitação destas crianças e proporcionando maior precisão no diagnóstico audiológico.Auditory Steady-State Responses (ASSR are being recognized as a promising technique in the assessment of hearing in children. AIM: To investigate the agreement level between results obtained from ASSR and click-ABR in a group of children with sensorineural hearing loss, in order to study the clinical applicability of this technique to evaluate the hearing status in young children. STUDY DESIGN: clinical prospective with a cross-sectional cohort. MATERIALS AND METHODS


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    A. A. Sazgar


    Full Text Available It has been shown recently that loud clicks evoke myogenic potentials in the tonically contracting sternocleidomastoid muscles. Studies have suggested that these potentials are of vestibular origin, especially of the saccule and inferior vestibular nerve. A pilot study was undertaken in our hospital to record vestibular evoked myogenic potentials (VEMP for the first time in Iran. Eighteen healthy volunteers (32 ears without history of otologic or vestibular disorders were subjected to the VEMP test. Twenty-one patients (26 ears with unilateral (6 patients and bilateral (5 patients high frequency sensorineural hearing loss with unknown etiology, acoustic neuroma (1 patient, Meniere’s disease (4 patients and unilateral low frequency sensorineural hearing loss without vestibular complaint (5 patients were also enrolled in this study. VEMP response to clicks was obtained from 84.4% of ears of healthy subjects. These subjects demonstrated short latency waves to click stimuli during tonic neck flexor activation. Mean latencies of first positive (p13 and first negative (n23 potentials in healthy subjects were 12.45 ± 1.9 ms and 20.8 ± 3.5 ms, respectively. Median latencies of these two potentials were 12.1 and 19.3 ms, respectively. We could record VEMP in 5 patients with unilateral and all patients with high and low frequency sensorineural hearing loss without vestibular complaint. In the patient with acoustic neuroma VEMP was absent on the affected side. This technique may offer a new method to evaluate otolith and sacculocollic pathways in human.

  2. Thermal grill conditioning: Effect on contact heat evoked potentials (United States)

    Jutzeler, Catherine R.; Warner, Freda M.; Wanek, Johann; Curt, Armin; Kramer, John L. K.


    The ‘thermal grill illusion’ (TGI) is a unique cutaneous sensation of unpleasantness, induced through the application of interlacing warm and cool stimuli. While previous studies have investigated optimal parameters and subject characteristics to evoke the illusion, our aim was to examine the modulating effect as a conditioning stimulus. A total of 28 healthy control individuals underwent three testing sessions on separate days. Briefly, 15 contact heat stimuli were delivered to the right hand dorsum, while the left palmar side of the hand was being conditioned with either neutral (32 °C), cool (20 °C), warm (40 °C), or TGI (20/40 °C). Rating of perception (numeric rating scale: 0–10) and evoked potentials (i.e., N1 and N2P2 potentials) to noxious contact heat stimuli were assessed. While cool and warm conditioning decreased cortical responses to noxious heat, TGI conditioning increased evoked potential amplitude (N1 and N2P2). In line with other modalities of unpleasant conditioning (e.g., sound, visual, and olfactory stimulation), cortical and possibly sub-cortical modulation may underlie the facilitation of contact heat evoked potentials. PMID:28079118

  3. Early Posttreatment Audiometry Underestimates Hearing Recovery after Intratympanic Steroid Treatment of Sudden Sensorineural Hearing Loss

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    Benjamin J. Wycherly


    Full Text Available Objective. To review our experience with intratympanic steroids (ITSs for the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL, emphasizing the ideal time to perform follow-up audiograms. Methods. Retrospective case review of patients diagnosed with ISSNHL treated with intratympanic methylprednisolone. Injections were repeated weekly with a total of 3 injections. Improvement was defined as an improved pure-tone average ≥20 dB or speech-discrimination score ≥20%. Results. Forty patients met the inclusion criteria with a recovery rate of 45% (18/40. A significantly increased response rate was found in patients having an audiogram >5 weeks after the first dose of ITS (9/13 over those tested ≤5 weeks after the first dose of ITS (9/27 (=0.03. Conclusions. Recovery from ISSNHL after ITS injections occurs more frequently >5 weeks after initiating ITS. This may be due to the natural history of sudden hearing loss or the prolonged effect of steroid in the inner ear.

  4. Electrically evoked middle latency responses in children with different cochlear implant ages and durations%不同植入年龄和植入后时间的EMLR反应特点研究

    Institute of Scientific and Technical Information of China (English)

    王子健; 马芙蓉; 潘滔; 鲁兆毅


    Objective This research, using electrically evoked middle latency responses (EMLR) as a measure of auditory performance, aimed to investigate the effect of age at cochlear implant on auditory perfor-mance and to study dynamic changes in auditory performance after cochlear implant, in the hope of providing theoretical foundation for guiding future cochlear implantation and rehabilitation training. Methods There were 42 prelingual deafness children included in this research, divided into 2 groups by age at cochlear im-plant, i.e. before 3 years (n=28) or after (n=14) (mean=2.98±1.64 years);and into 4 groups by duration of implant use, i.e. less than 6 months (n=12), 6 to 12 months (n=16), 12 to 24 months (n=4) and more than 24 months (n=10) (mean=15.06±15.53 months). EMLRs were tested and results analyzed for each group. Result EMLRs were induced in 38 of the 42 children (90.48%). The PaNb amplitude was 2.34 ± 1.26μV in children who received implants before 3 years of age, and 1.48 ± 0.49 μV in those implanted after 3 years of age (p<0.05). Pa latency was 30.52±0.85 ms in children who had used cochlear implant for 6 to 12 months, and 25.98± 1.80 ms in those who had used implant for more than 24 months (p<0.05). Conclusion The age at cochlear im-plant and the duration after cochlear implantation affect auditory performance in children with prelingual deaf-ness, which appears to be bettern in those implanted before 3 years of age than after. Auditory performance ap-pears to rapidly improve in the first 2 years after implantation, suggesting that rehabilitation training in the first 2 years after cochlear implant is very important.%目的:利用电诱发中潜伏期反应(Electrically evoked middle latency response,EMLR)对语前聋人工耳蜗植入患儿进行听觉功能评估,了解人工耳蜗植入年龄对听觉功能的影响,研究语前聋患儿人工耳蜗植入后听觉功能的变化规律。为人工耳蜗植入时间的选择及植入


    Institute of Scientific and Technical Information of China (English)

    佘晓俊; 崔博; 吴铭权; 马强; 刘洪涛


    目的 研究噪声暴露对大鼠听觉脑干反应(ABR)的影响,及大鼠短声ABR(C-ABR)和短纯音ABR(Tb-ABR)的特点,以探讨Tb-ABR在听力评估中的价值.方法 将成年SD大鼠随机分为噪声组和正常组,每组7只(14耳).噪声组暴露于100 dB(SPL)白噪声,6 h/d,连续12周.噪声停止后24 h分别测定C-ABR和Tb-ABR(刺激声2、4、8、16、32 kHz).对2组的ABR结果进行统计分析.结果 随着刺激声从32 kHz到2 kHz,正常大鼠Tb-ABR各波的潜伏期延长;与C-ABR比较,Tb-ABR各频率波Ⅰ、Ⅱ、Ⅳ的潜伏期都延迟,差异有显著性(P<0.01).大鼠听力在16 kHz比较敏感,阈值较低.噪声组大鼠在8 kHz听力损失最重,升高11 dB;各种短纯音刺激时,Tb-ABR各波潜伏期及峰间潜伏期无明显变化.结论 正常大鼠在各个频率的听力闽值、敏感性不同,噪声对各频率听力影响也不同;Tb-ABR较C-ABR更能反映听力损失的频率特性.%Objective To study the effects of noise exposure on click-evoked auditory brainstem responses( CABR) and tone burst-evoked ABR(Tb-ABR) in rats, so as to provide the reference for application of Tb-ABR to hearing evaluation.Methods Fourteen SD rats were divided into two groups, named the control group and the noise exposure group with seven rats per group(fourteen ears).The noise exposure group were exposed to the white noise[100 dB(SPL),6 h/day,12 weeks].C-ABR and Tb-ABR(2,4,8, 16,32 kHz) were measured 24 hours after noise exposure.Results The peak latency in normal rats was prolonged when the stimulate tone changed from 32 kHz to 2 kHz; the peak latency of TbABR with any frequency was significantly longer than that of C-ABR ( P < 0.01 ); the hearing threshold at 16 kHz of TbABR was the lowest, and the hearing was the best.The hearing loss in noise exposure group was most severe at 8 kHz ( 11 dB more than the control).The thresholds of C-ABR and Tb-ABR of noise exposure group were higher than those of control group.The peak latency of

  6. Visual evoked potentials in patients after methanol poisoning

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    Pavel Urban


    Full Text Available Objectives: We report the results of the visual evoked potentials (VEP examination in patients after severe poisoning by methanol. Material and Methods: The group of 47 patients (38 males and 9 females was assembled out of persons who survived an outbreak of poisoning by the methanol adulterated alcohol beverages, which happened in the Czech Republic in 2012–2013. The visual evoked potentials examination was performed using monocular checkerboard pattern-reversal stimulation. Two criteria of abnormality were chosen: missing evoked response, and wave P1 latency > 117 ms. Non-parametric statistical methods (median, range, and the median test were used to analyze factors influencing the VEP abnormality. Results: The visual evoked potential was abnormal in 20 patients (43%, 5 of them had normal visual acuity on the Snellen chart. The VEP abnormality did not correlate significantly with initial serum concentrations of methanol, formic acid or lactate; however, it showed statistically significant inverse relation to the initial serum pH: the subgroup with the abnormal VEP had significantly lower median pH in comparison with the subgroup with the normal VEP (7.16 vs. 7.34, p = 0.04. The abnormality was not related to chronic alcohol abuse. Conclusions: The visual evoked potentials examination appeared sensitive enough to detected even subclinical impairment of the optic system. Metabolic acidosis is likely to be the key factor related to the development of visual damage induced by methanol. The examination performed with a delay of 1–9 months after the poisoning documented the situation relatively early after the event. It is considered as a baseline for the planned long-term follow-up of the patients, which will make it possible to assess the dynamics of the observed changes, their reversibility, and the occurrence of potential late sequelae.

  7. Short latency vestibular potentials evoked by electrical round window stimulation in the guinea pig. (United States)

    Bordure, P; Desmadryl, G; Uziel, A; Sans, A


    Short-latency potentials evoked by round window electrical stimulation were recorded in guinea pig by means of vertex-pinna skin electrodes using averaging techniques. Constant current shocks of 20 microseconds or 50 microseconds (25-300 microA) were used to evoke both auditory and vestibular brain-stem potentials. Pure auditory potentials, comparable to those evoked by acoustic clicks, were obtained by 20 microseconds electrical stimuli and disappeared during an auditory masking procedure made with a continuous white noise (110 dB SPL). Short latency potentials labeled V1, V2 and V3 were obtained by 50 microseconds electrical stimuli during an auditory masking procedure. This response disappeared after specific vestibular neurectomy, whereas the auditory response evoked by acoustic clicks or by electrical stimulation remained unchanged, suggesting that these latter potentials had a vestibular origin.

  8. Prestimulus amplitudes modulate P1 latencies and evoked traveling alpha waves

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    Nicole Alexandra Himmelstoss


    Full Text Available Traveling waves have been well documented in the ongoing, and more recently also in the evoked EEG. In the present study we investigate what kind of physiological process might be responsible for inducing an evoked traveling wave. We used a semantic judgment task which already proved useful to study evoked traveling alpha waves that coincide with the appearance of the P1 component. We found that the P1 latency of the leading electrode is significantly correlated with prestimulus amplitude size and that this event is associated with a transient change in alpha frequency. We assume that cortical background excitability, as reflected by an increase in prestimulus amplitude, is responsible for the observed change in alpha frequency and the initiation of an evoked traveling trajectory.

  9. An inventory and update of jealousy-evoking partner behaviours in modern society. (United States)

    Dijkstra, Pieternel; Barelds, Dick P H; Groothof, Hinke A K


    The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's extra-dyadic involvement with someone else by means of modern communication devices, such as the Internet. A second study examined the extent to which undergraduates and a community sample experienced jealousy in response to these partner behaviours. Results showed that explicit unfaithful behaviours evoked most feelings of jealousy, followed by a partner's emotional or romantic involvement with someone else by means of modern communication devices. In general, older individuals responded with less jealousy in response to a partner's unfaithful and suspicious behaviours. Clinical implications are discussed.

  10. [Intraoperative Visual Evoked Potential Monitoring]. (United States)

    Hayashi, Hironobu; Kawaguchi, Masahiko


    Visual evoked potential (VEP) is recorded from the back of the head, which is elicited by retinal stimulation transmitted through optic nerve, optic chiasm, optic tract lateral geniculate body, optic radiation and finally cortical visual area. VEP monitoring did not prevail since 1990s because marked intra-individual difference and instability of VEP recording limited the clinical usefulness under inhalation anesthetic management and techniques of VEP monitoring at the time. However, recent advances in techniques including a new light-stimulating device consisting of high-luminosity LEDs and induction of electroretinography to ascertain the arrival of the stimulus at the retina provided better conditions for stable VEP recording under general anesthesia. In addition, the introduction of total intravenous anesthesia using propofol is important for the successful VEP recordings because inhaled anesthetics have suppressive effect on VEP waveform. Intraoperative VEP has been considered to monitor the functional integrity of visual function during neurosurgical procedures, in which the optic pathway is at a risk of injury. Intraoperative VEP monitoring may allow us to detect reversible damage to the visual pathway intraoperatively and enable us to prevent permanent impairment.

  11. Somatosensory evoked magnetic fields in patients with stroke. (United States)

    Maclin, E L; Rose, D F; Knight, J E; Orrison, W W; Davis, L E


    We used magnetoencephalography to evaluate areas of sensory cortex in patients with ischemic strokes involving the somatomotor system. We measured somatosensory evoked magnetic fields using a 7-channel neuromagnetometer and estimated the location of cortical responses to median nerve stimulation in 5 patients with cortical or subcortical strokes involving the somatomotor system. All patients underwent quantitative neurological examinations and a high resolution volumetric magnetic resonance imaging. The estimated current dipoles were localized onto the patient's own MRI scan in all patients with measurable responses. The location of the estimated dipole was always in non-infarcted tissue in the anatomical region of the somatosensory cortex. In 1 patient the somatosensory dipole localized to a peninsula of cortex flanked by infarcted tissue. Single photon emission computed tomography found the localized area of cortex to have significant blood flow. The estimated current dipole strengths of somatosensory evoked fields from median nerve stimulation correlated significantly (r = 0.95, P graphesthesia). The combination of evoked magnetic field recording and magnetic resonance imaging is a promising non-invasive technology for studying brain function in patients with cerebrovascular disease.

  12. [Long-latency auditory evoked potentials in cochlear implants]. (United States)

    Mata, J J; Jiménez, J M; Pérez, J; Postigo, A; Roldán, B


    Cortical evoked potentials were evaluated in patients with cochlear implants. In a group of 8 adults of different ages, the lingual state before implantation and during rehabilitation were evaluated. Using cortical evoked potentials, the results of the P300 wave in response to two tones, one frequent (1,000 Hz) and the other infrequent (2,000 Hz), presented at 70 and 80 dB HL were studied. Results were analyzed and compared in relation to locutive state, rehabilitation stage, and intensity of stimulus. Absolute latencies did not differ significantly. However, latency values in relation to reaction time were significantly longer in prelingual than in postlingual patients (p test). The results confirmed the normality of central cognitive processes in patients with cochlear implants in objective assessment of P300 latency. The results suggest differences between prelingual and postlingual patients in relation to central signal processing.

  13. Visual Evoked Potentials in Rett Syndrome

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    J. Gordon Millichap


    Full Text Available Investigators from the Boston Children's Hospital recorded pattern-reversal visual evoked potentials (VEPs in Mecp2 heterozygous female mice and in 34 girls with Rett syndrome (RTT.

  14. Evoked potentials in neuroinfections in children

    Directory of Open Access Journals (Sweden)

    V. N. Komantsev


    Full Text Available We present the results of the neurophysiological study in which 95 children with viral encephalitis and 30 children with meningitis (age from 2 up to 17 years undergo evoked potentials investigation. Some specific features of evoked potentials in neuroinfections have been shown to correlate with the course of disease and the age of the patients. We give a description of a logistic model of predicting outcomes in such patients by complex diagnostic method. We have found that evoked potentials may be successfully implemented in correcting the therapeutic strategies. Study of evoked potentials in neuroinfections in children can define the severity and extent of lesions and help to identify subclinical dysfunction and monitor the recovery processes under the therapy.

  15. Exploring the Mechanisms of Exercise-Induced Hypoalgesia Using Laser Evoked Potentials

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    Matthew David Jones


    Full Text Available Exercise-induced hypoalgesia is well described, but the underlying mechanisms are unclear. The aim of this study was to examine the effect of exercise on somatosensory evoked potentials, laser evoked potentials, pressure pain thresholds and heat pain thresholds. These were recorded before and after 3-min of isometric elbow flexion exercise at 40% of the participant’s maximal voluntary force, or an equivalent period of rest. Exercise-induced hypoalgesia was confirmed in two experiments (Experiment 1 – SEPs; Experiment 2 – LEPs by increased pressure pain thresholds at biceps brachii (24.3% and 20.6% increase in Experiment 1 and 2, respectively; both d > 0.84 and p 0.57 and p < 0.001. In contrast, heat pain thresholds were not significantly different after exercise (forearm: 10.8% increase, d = 0.35, p = 0.10; hand: 3.6% increase, d = 0.06, p = 0.74. Contrasting effects of exercise on the amplitude of laser evoked potentials (14.6% decrease, d = -0.42, p = 0.004 and somatosensory evoked potentials (10.9% increase, d = -0.02, p = 1.72 were also observed, while an equivalent period of rest showed similar habituation (laser evoked potential: 7.3% decrease, d = -0.25, p = 0.14; somatosensory evoked potential: 20.7% decrease, d = -0.32, p = 0.006. The differential response of pressure pain thresholds and heat pain thresholds to exercise is consistent with relative insensitivity of thermal nociception to the acute hypoalgesic effects of exercise. Conflicting effects of exercise on somatosensory evoked potentials and laser evoked potentials were observed. This may reflect non-nociceptive contributions to the somatosensory evoked potential, but could also indicate that peripheral nociceptors contribute to exercise-induced hypoalgesia.

  16. Enhanced auditory evoked potentials in musicians:A review of recent findings

    Institute of Scientific and Technical Information of China (English)


    Auditory evoked potentials serve as an objective mode for assessment to check the functioning of the auditory system and neuroplasticity. Literature has reported enhanced electrophysiological responses in musicians, which shows neuroplasticity in musicians. Various databases including PubMed, Google, Google Scholar and Medline were searched for references related to auditory evoked potentials in musicians from 1994 till date. Different auditory evoked potentials in musicians have been summarized in the present article. The findings of various studies may support as evidences for music-induced neuroplasticity which can be used for the treatment of various clinical disorders. The search results showed enhanced auditory evoked potentials in musicians compared to non-musicians from brainstem to cortical levels. Also, the present review showed enhanced attentive and pre-attentive skills in musicians compared to non-musicians.

  17. The Role of Odor-Evoked Memory in Psychological and Physiological Health

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    Rachel S. Herz


    Full Text Available This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

  18. The Role of Odor-Evoked Memory in Psychological and Physiological Health (United States)

    Herz, Rachel S.


    This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing. PMID:27447673

  19. Characterization of Motor and Somatosensory Evoked Potentials in the Yucatan Micropig Using Transcranial and Epidural Stimulation. (United States)

    Benavides, Francisco D; Santamaria, Andrea J; Bodoukhin, Nikita; Guada, Luis G; Solano, Juan P; Guest, James D


    Yucatan micropigs have brain and spinal cord dimensions similar to humans and are useful for certain spinal cord injury (SCI) translational studies. Micropigs are readily trained in behavioral tasks, allowing consistent testing of locomotor loss and recovery. However, there has been little description of their motor and sensory pathway neurophysiology. We established methods to assess motor and sensory cortical evoked potentials in the anesthetized, uninjured state. We also evaluated epidurally evoked motor and sensory stimuli from the T6 and T9 levels, spanning the intended contusion injury epicenter. Response detection frequency, mean latency and amplitude values, and variability of evoked potentials were determined. Somatosensory evoked potentials were reliable and best detected during stimulation of peripheral nerve and epidural stimulation by referencing the lateral cortex to midline Fz. The most reliable hindlimb motor evoked potential (MEP) occurred in tibialis anterior. We found MEPs in forelimb muscles in response to thoracic epidural stimulation likely generated from propriospinal pathways. Cranially stimulated MEPs were easier to evoke in the upper limbs than in the hindlimbs. Autopsy studies revealed substantial variations in cortical morphology between animals. This electrophysiological study establishes that neurophysiological measures can be reliably obtained in micropigs in a time frame compatible with other experimental procedures, such as SCI and transplantation. It underscores the need to better understand the motor control pathways, including the corticospinal tract, to determine which therapeutics are suitable for testing in the pig model.

  20. Cortico-cortical evoked potentials for sites of early versus late seizure spread in stereoelectroencephalography. (United States)

    Lega, Bradley; Dionisio, Sasha; Flanigan, Patrick; Bingaman, William; Najm, Imad; Nair, Dileep; Gonzalez-Martinez, Jorge


    Cortico-cortical evoked potentials offer the possibility of understanding connectivity within seizure networks to improve diagnosis and more accurately identify candidates for seizure surgery. We sought to determine if cortico-cortical evoked potentials and post-stimulation oscillatory changes differ for sites of EARLY versus LATE ictal spread. 37 patients undergoing stereoelectroencephalography were tested using a cortico-cortical evoked potential paradigm. All electrodes were classified according to the speed of ictal spread. EARLY spread sites were matched to a LATE spread site equidistant from the onset zone. Root-mean-square was used to quantify evoked responses and post-stimulation gamma band power and coherence were extracted and compared. Sites of EARLY spread exhibited significantly greater evoked responses after stimulation across all patients (t(36)=2.973, p=0.004). Stimulation elicited enhanced gamma band activity at EARLY spread sites (t(36)=2.61, p=0.03, FDR corrected); this gamma band oscillation was highly coherent with the onset zone. Cortico-cortical evoked potentials and post-stimulation changes in gamma band activity differ between sites of EARLY versus LATE ictal spread. The oscillatory changes can help visualize connectivity within the seizure network.

  1. Perceptual learning of acoustic noise generates memory-evoked potentials. (United States)

    Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel


    Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics.

  2. Baroreceptor activation attenuates attentional effects on pain-evoked potentials. (United States)

    Gray, Marcus A; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D


    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis, we explored in a group of healthy participants the combined effects of cue-induced expectancy and baroreceptor activity on the amplitude of pain-evoked ERPs. Brief nociceptive skin stimuli were delivered during a simple visual task; half were preceded by a visual forewarning cue, and half were unpredictable. Nociceptive stimuli were timed to coincide either with systole (maximum activation of cardiac baroreceptors) or with diastole (minimum baroreceptor activation). We observed a strong interaction between expectancy and cardiac timing for the amplitude of the P2 ERP component; no effects were observed for the N2 component. Cued stimuli were associated with larger P2 amplitude, but this effect was abolished for stimuli presented during baroreceptor activation. No cardiac timing effect was observed for un-cued stimuli. Taken together, these findings suggest a close integration of cognitive-affective aspects of expectancy and baroreceptor influences on pain, and as such may cast further light on mechanisms underlying mental and physiological contributions to clinical pain.

  3. Awareness during anaesthesia for surgery requiring evoked potential monitoring: A pilot study

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    Pritish J Korula


    Full Text Available Background: Evoked potential monitoring such as somatosensory-evoked potential (SSEP or motor-evoked potential (MEP monitoring during surgical procedures in proximity to the spinal cord requires minimising the minimum alveolar concentrations (MACs below the anaesthetic concentrations normally required (1 MAC to prevent interference in amplitude and latency of evoked potentials. This could result in awareness. Our primary objective was to determine the incidence of awareness while administering low MAC inhalational anaesthetics for these unique procedures. The secondary objective was to assess the adequacy of our anaesthetic technique from neurophysiologist′s perspective. Methods: In this prospective observational pilot study, 61 American Society of Anesthesiologists 1 and 2 patients undergoing spinal surgery for whom intraoperative evoked potential monitoring was performed were included; during the maintenance phase, 0.7-0.8 MAC of isoflurane was targeted. We evaluated the intraoperative depth of anaesthesia using a bispectral (BIS index monitor as well as the patients response to surgical stimulus (PRST scoring system. Post-operatively, a modified Bruce questionnaire was used to verify awareness. The adequacy of evoked potential readings was also assessed. Results: Of the 61 patients, no patient had explicit awareness. Intraoperatively, 19 of 61 patients had a BIS value of above sixty at least once, during surgery. There was no correlation with PRST scoring and BIS during surgery. Fifty-four out of 61 patient′s evoked potential readings were deemed ′good′ or ′fair′ for the conduct of electrophysiological monitoring. Conclusions: This pilot study demonstrates that administering low MAC inhalational anaesthetics to facilitate evoked potential monitoring does not result in explicit awareness. However, larger studies are needed to verify this. The conduct of SSEP electrophysiological monitoring was satisfactory with the use of this

  4. Cerebral oxygen delivery and consumption during evoked neural activity

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    Alberto L Vazquez


    Full Text Available Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI.

  5. [Topographic aspects of visual evoked potentials recorded after flash-pattern stimulation in normal subjects]. (United States)

    Samson-Dollfus, D; Parain, D; Menard, J F; Layet, A; Nehili, F; Dreano, E


    Visual evoked responses have been recorded on 14 leads placed on the scalp. They were localised on the central, parietal, temporal and occipital regions. The common reference was linked-ears. The stimulus consisted of a flash pattern. The size of the pattern and of each square was respectively of 20 degrees and 30 min. The stimulation of the total visual field had evoked two families of curves. One of these types of curves was posterior (occipital, temporal and parietal) and consisted in a positive, negative, positive wave (100, 136, 200 msec on average) and the second type was localised on the central leads and much more rhythmic than the posterior response. The initial complex (negative, positive, negative, positive: 70, 92, 120, 178 msec) was followed by a slow after-discharge. The half-field stimulation evoked a P100 component on the contralateral posterior leads, but this P100 was less prominent on the ipsilateral posterior leads. The modifications were particularly evident at the level of the temporal posterior electrodes. This P100 component was the only wave to be modified by half-field visual stimulation. The posterior N136 and P200 wave and all the rhythmic central response were exactly the same with half or total visual field stimulation. The results have obviously shown that the different waves of the visual evoked responses are not coming from the same sources. The interpretation of multichannel evoked recordings was therefore very difficult.

  6. Avaliação dos limiares auditivos com e sem equipamento de proteção individual Pure tone audiometry with and without specific ear protectors

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    Carlos Antonio Rodrigues de Faria


    Full Text Available Os autores realizaram estudo caso-controle audiométrico em indivíduos com e sem protetor auricular auditivo. OBJETIVOS: O objetivo do estudo foi avaliar a real atenuação individual dado pelos protetores. MATERIAL E MÉTODO: Foram avaliados 30 indivíduos (ou 60 orelhas de diferentes atividades profissionais, de ambos os sexos, com idades entre 20 e 58 anos, apresentando audição normal e tendo realizado repouso auditivo de 10 horas, submetidos a exame audiométrico com e sem protetor auricular auditivo, no período de fevereiro a julho de 2003, utilizando protetor tipo plugue. Avaliou-se as audiometrias nas vias aérea e óssea em freqüências de 500 a 4000Hz. RESULTADOS: Os resultados foram analisados estatisticamente e comparados aos dados fornecidos pelo fabricante. Assim se observou em ouvido real os níveis de atenuação auditiva obtidos com o uso destes produtos. CONCLUSÃO: Os resultados permitiram chegar à conclusão de que os índices fornecidos pelos fabricantes foram compatíveis com os que obtive nos testes.The authors evaluated pure tone audiometry with and without specific ear protectors. AIM: The purpose of this case control study was to measure the level of sound attenuation by earplugs. MATERIAL AND METHODS: The evaluation included sixty ears of 30 subjects of both sexes, aged between 20 and 58 years, of various professional activities, with normal hearing thresholds, and following ten hours of auditory rest. The statistical results of pure tone audiometry at 500 to 4000 Hertz with and without specific ear protectors were analyzed. RESULTS: These results were compared with those provided by the ear protector manufacturer. CONCLUSION: The results show that the rate of sound reduction was similar to the manufacturer's specifications.

  7. Click-evoked otoacoustic emissions in children and adolescents with gender identity disorder

    NARCIS (Netherlands)

    Burke, Sarah M; Menks, Willeke M; Cohen-Kettenis, Peggy T; Klink, Daniel T; Bakker, J.


    Click-evoked otoacoustic emissions (CEOAEs) are echo-like sounds that are produced by the inner ear in response to click-stimuli. CEOAEs generally have a higher amplitude in women compared to men and neonates already show a similar sex difference in CEOAEs. Weaker responses in males are proposed to

  8. A Parallel World for the World Bank: A Case Study of Urgent: Evoke, An Educational Alternate Reality Game

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    David I. Waddington


    Full Text Available In 2010, the World Bank launched Urgent: Evoke, an alternate reality game. Conceived in response to the demands of African universities, the game was designed to promote the World Bank Institute’s vision of positive global change through social innovation, and made substantial use of Web 2.0 tools such as blogs, personal profiles, and social networks. This article offers a case study of Urgent: Evoke, divided into four sections: first, the potential to use video games as citizenship education tools is discussed; second, the unique game genre (alternate reality games into which Evoke falls is explained and some possible uses of this genre in higher education are examined; third, the functioning of the Evoke game world is explained; and fourth, the results of the Evoke educational project are assessed. The case study concludes with some commentary on Evoke’s ideological message, which those less sympathetic to capitalism may view as problematic.

  9. Increasing Pain Sensation Eliminates the Inhibitory Effect of Depression on Evoked Pain in Rats (United States)

    Wang, Ning; Li, Sheng-Guang; Lin, Xiao-Xiao; Su, Yuan-Lin; Qi, Wei-Jing; Wang, Jin-Yan; Luo, Fei


    Although previous studies have suggested that depression may be associated with inhibition of evoked pain but facilitation of spontaneous pain, the mechanisms underlying these relationships are unclear. The present study investigated whether the difference between evoked and spontaneous pain on sensory (descending inhibition) and affective (avoidance motivation) components contributes to the divergent effects of depression on them. Depressive-like behavior was produced in male Wistar rats by unpredictable chronic mild stress (UCMS). Tone-laser conditioning and formalin-induced conditioned place avoidance (F-CPA) were used to explore avoidance motivation in evoked and spontaneous pain, respectively. Behavioral pharmacology experiments were conducted to examine descending inhibition of both evoked (thermal stimulation) and spontaneous pain behavior (formalin pain). The results revealed that the inhibitory effect of depression on evoked pain was eliminated following repeated thermal stimuli. Avoidance behavior in the tone-laser conditioning task was reduced in UCMS rats, relative to controls. However, avoidance motivation for formalin pain in the UCMS group was similar to controls. 5-HT1A receptor antagonism interfered with inhibition of pain responses over time. The present study demonstrated that the inhibitory effect of depression on evoked pain dissipates with increased nociception and that the sensory-discriminative and affective-motivational components of pain are jointly involved in the divergent effects of depression on pain. PMID:27733820

  10. Cervical intraspinal microstimulation evokes robust forelimb movements before and after injury (United States)

    Sunshine, Michael D.; Cho, Frances S.; Lockwood, Danielle R.; Fechko, Amber S.; Kasten, Michael R.; Moritz, Chet T.


    Objective. Intraspinal microstimulation (ISMS) is a promising method for reanimating paralyzed limbs following neurological injury. ISMS within the cervical and lumbar spinal cord is capable of evoking a variety of highly-functional movements prior to injury, but the ability of ISMS to evoke forelimb movements after cervical spinal cord injury is unknown. Here we examine the forelimb movements and muscles activated by cervical ISMS both before and after contusion injury. Approach. We documented the forelimb muscles activated and movements evoked via systematic stimulation of the rodent cervical spinal cord both before injury and three, six and nine weeks following a moderate C4/C5 lateralized contusion injury. Animals were anesthetized with isoflurane to permit construction of somatotopic maps of evoked movements and quantify evoked muscle synergies between cervical segments C3 and T1. Main results. When ISMS was delivered to the cervical spinal cord, a variety of responses were observed at 68% of locations tested, with a spatial distribution that generally corresponded to the location of motor neuron pools. Stimulus currents required to achieve movement and the number of sites where movements could be evoked were unchanged by spinal cord injury. A transient shift toward extension-dominated movements and restricted muscle synergies were observed at three and six weeks following injury, respectively. By nine weeks after injury, however, ISMS-evoked patterns were similar to spinally-intact animals. Significance. The results demonstrate the potential for cervical ISMS to reanimate hand and arm function following spinal cord injury. Robust forelimb movements can be evoked both before and during the chronic stages of recovery from a clinically relevant and sustained cervical contusion injury.

  11. Sense Estimation and Instrumental Evaluation of Fabric-Evoked Prickle

    Institute of Scientific and Technical Information of China (English)

    敖利民; 郁崇文


    In this paper, the mechanism of fabric-evoked prickle is discussed, which indicates that the mechanical stimuli aroused by the fiber ends on the fabric surface to the skin-sensory receptors are responsible for prickle. The factors influencing the intensity of prickle are specialized and anatomized. Several means of sense estimate, including the corresponding statistical measures, are described. A few groping objective methods of evaluating prickle are analyzed, including the testing principles, the advantages and the disadvantages. At last, a new concept is proposed on the objective evaluation of prickle.

  12. Brain correlates of music-evoked emotions. (United States)

    Koelsch, Stefan


    Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders.

  13. 自觉听力正常耳鸣患者纯音听力及畸变产物耳声发射临床分析%Audiometry and distortion product otoacoustic emissions in tinnitus patients without hearing complaints

    Institute of Scientific and Technical Information of China (English)

    王晓晖; 肖玉丽


    Objective To study pure tone audiometry and distortion product otoacoustic emissions (DPOAE) features in tinnitus patients who do not perceive hearing loss. Methods Pure tone threshold, hearing loss, SNR of DPOAE were performed in 114 (190 ears) adults with tinnitus cases with never perceived hearing loss, investigate the relationship between every risk factor and tinnitus. Results Audiometry showed high frequency hearing loss in 46.31% (88/ 190), low frequency hearing loss in 14.73% (28/190), normal hearing in 23.15% (44/190), and other types of audio-grams in 15.78%(30/190) of the patients. Risk factors included noise exposure, fatigue, stress, and pre-existing diseases. There was a negative correlation between DPOAE amplitude and pure tone threshold. DPOAE response frequencies were closely related to frequency distribution of pure tone thresholds. Conclusion A significant number of patients with tinnitus but no hearing complaints may still have abnormal hearing, especially in the high frequency range. A negative correlation exists between DPOAE amplitude and pure tone threshold. DPOAEs may serve as an objective indicator of the level of hearing loss in tinnitus patients with no hearing complaints, which may be of value in the clinic.%目的 分析自觉听力正常耳鸣患者的纯音听力特征,并探讨自觉听力正常耳鸣患者畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)测定值与纯音听阈值之间的相关性及其意义.方法 2010-2011年在我科就诊的以耳鸣为第一主诉但无明显自觉听力障碍患者114例(190耳),对所有入组患者进行纯音测听及DPOAE检测.分析DPOAE测定值与纯音听阈值之间的相关性,并结合其发病的可能危险因素进行相关分析.结果 自觉听力正常的耳鸣患者中,听力异常可达76.84% (146/190).纯音测听表现为:高频下降型46.31% (88/190);低频下降型14.73% (28/190);正常23.15% (44/190);其它类型15.78% (30/190).

  14. Evoked brain potentials and disability in brain-damaged patients. (United States)

    Rappaport, M; Hall, K; Hopkins, K; Belleza, T; Berrol, S; Reynolds, G


    Various measures of evoked brain potential abnormality (EPA) were correlated with disability ratings (DR) for 35 brain-damaged patients. EPA data consisted of judgements of abnormality of ipsilateral, contralateral and bilateral responses to auditory and visual stimuli reflecting activity in the brain stem, subcortex and cortex. DR data were obtained from a scale developed for this study to quantize and categorize patients with a wide range of disabilities from coma to normal functioning. EPA scores based on visual and auditory cortical responses showed significantly positive correlations with degree of disability. Visual response correlation was .49, auditory .38 and combined visual and auditory .51. It was concluded that EPA measures can reflect disability independently of clinical information. They are useful in assessing brain function in general and, specifically, in assessing impairment of sensory function. The evoked potential technique was particularly useful in patients who were not able to participate fully in their own examination. There were indications that the technique may also be valuable in monitoring progress and in predicting clinical outcome in brain-damaged patients.

  15. [Effect of sleep deprivation on visual evoked potentials and brain stem auditory evoked potentials in epileptics]. (United States)

    Urumova, L T; Kovalenko, G A; Tsunikov, A I; Sumskiĭ, L I


    The article reports on the first study of the evoked activity of the brain in epileptic patients (n = 20) following sleep deprivation. An analysis of the data obtained has revealed a tendency to the shortening of the peak latent intervals of visual evoked potentials in the range of 100-200 mu sec and the V component and the interpeak interval III-V of evoked auditory trunk potentials in patients with temporal epilepsy. The phenomenon may indicate the elimination of stabilizing control involving the specific conductive pathways and, possibly, an accelerated conduction of a specific sensor signal.

  16. Spatial Tuning Studies of the Pattern Evoked Electroretinogram. (United States)

    Thompson, Dorothy Ann


    Available from UMI in association with The British Library. The locus of origin of the pattern evoked electroretinogram, (PERG), has been the subject of considerable discussion. A novel approach was adopted in this study to further elaborate the nature of the PERG evoked by pattern onset/offset presentation. The PERG was found to be linearly related to stimulus contrast and in particular was linearly related to the temporal contrast of the retinal image, when elicited by patterns of low spatial frequency. At high spatial frequencies the retinal image contrast is significantly reduced because of optical degradation. This is described by the eye's modulation transfer function (MTF). The retinal contrasts of square wave grating and chequerboard patterns of increasing spatial frequency were found by filtering their Fourier transforms by the MTF. The filtered pattern harmonics were then resynthesised to constitute a profile of retinal image illuminance from which the temporal and spatial contrast of the image could be calculated. A space-averaged temporal contrast attenuation factor was applied to PERGs evoked by low spatial frequency patterns to predict the retinal illuminance response elicited by a finer pattern. The predicted response was subtracted from the recorded signal and the residual waveform was proposed to represent pattern specific activity. An additional correction for the attenuation of spatial contrast was applied to the extracted pattern specific response. Pattern specific responses are the predicted result of iso-contrast retinal pattern stimulation. The pattern specific responses demonstrate a striking bandpass spatial selectivity which peaks at higher spatial frequencies in the more central retina. The variation of spatial sensitivity with eccentricity corresponds closely with estimated ganglion receptive field centre separation and psychophysical data. The variation of retinal structure with eccentricity in the form of the volumes of the nuclear

  17. Carbenoxolone blocks the light-evoked rise in intracellular calcium in isolated melanopsin ganglion cell photoreceptors.

    Directory of Open Access Journals (Sweden)

    Jayne R Bramley

    Full Text Available BACKGROUND: Retinal ganglion cells expressing the photopigment melanopsin are intrinsically photosensitive (ipRGCs. These ganglion cell photoreceptors send axons to several central targets involved in a variety of functions. Within the retina ipRGCs provide excitatory drive to dopaminergic amacrine cells via glutamatergic signals and ipRGCs are coupled to wide-field GABAergic amacrine cells via gap junctions. However, the extent to which ipRGCs are coupled to other retinal neurons in the ganglion cell layer via gap junctions is unclear. Carbenoxolone, a widely employed gap junction inhibitor, greatly reduces the number of retinal neurons exhibiting non-rod, non-cone mediated light-evoked Ca(2+ signals suggesting extensive intercellular coupling between ipRGCs and non-ipRGCs in the ganglion cell layer. However, carbenoxolone may directly inhibit light-evoked Ca(2+ signals in ipRGCs independent of gap junction blockade. METHODOLOGY/PRINCIPAL FINDINGS: To test the possibility that carbenoxolone directly inhibits light-evoked Ca(2+ responses in ipRGCs, the light-evoked rise in intracellular Ca(2+ ([Ca(2+](i was examined using fura-2 imaging in isolated rat ipRGCs maintained in short-term culture in the absence and presence of carbenoxolone. Carbenoxolone at 50 and 100 µM concentrations completely abolished the light-evoked rise in [Ca(2+](i in isolated ipRGCs. Recovery from carbenoxolone inhibition was variable. CONCLUSIONS/SIGNIFICANCE: We demonstrate that the light-evoked rise in [Ca(2+](i in isolated mammalian ganglion cell photoreceptors is inhibited by carbenoxolone. Since the light-evoked increase in [Ca(2+](i in isolated ipRGCs is almost entirely due to Ca(2+ entry via L-type voltage-gated calcium channels and carbenoxolone does not inhibit light-evoked action potential firing in ipRGCs in situ, carbenoxolone may block the light-evoked increase in [Ca(2+](i in ipRGCs by blocking L-type voltage-gated Ca(2+ channels. The ability of

  18. Color Evoked Potentials in Adults and Infants. (United States)

    White, Carroll T.; And Others

    This paper discusses recent studies of the adult visual evoked potential (VEP) which have indicated that specific components of the complex waveform obtained are related to the three basic color processes, and that these components interact in ways that seem to agree with opponent-colors phenomena. The components identified as being related to the…


    Institute of Scientific and Technical Information of China (English)


    Objective To study direct cortical electrical stimulation technique for the recording of motor evoked potentials under general anesthesia in central sulcus lesions. Methods The largest N20-P25 response was recorded from postcentral gyrus by intraoperative monitoring of cortical motor evoked potentials in 10 patients with intracranial lesions near or in the central area. The muscles of upper extremity in all patients were activated by delivering stimulus to cortical areas continuously. Moving the cortical electrodes forward, the largest P20-N25 response, SEP phase reversal,was obtained as a motor center stimulus. In this site of cortex, a short train stimulation elicited reproducible muscle action potentials that could be observed from the oscilloscope without averaging.Results MEPs can be recorded, pre- and post-operatively, without motor deficits of upper limbs in all patients.Conclusion This technique seems to be preferable for intraoperative localization of motor evoked potentials in central sulcus lesions under total intravenous anesthesia.

  20. Peripheral nerve injury increases glutamate-evoked calcium mobilization in adult spinal cord neurons

    Directory of Open Access Journals (Sweden)

    Doolen Suzanne


    Full Text Available Abstract Background Central sensitization in the spinal cord requires glutamate receptor activation and intracellular Ca2+ mobilization. We used Fura-2 AM bulk loading of mouse slices together with wide-field Ca2+ imaging to measure glutamate-evoked increases in extracellular Ca2+ to test the hypotheses that: 1. Exogenous application of glutamate causes Ca2+ mobilization in a preponderance of dorsal horn neurons within spinal cord slices taken from adult mice; 2. Glutamate-evoked Ca2+ mobilization is associated with spontaneous and/or evoked action potentials; 3. Glutamate acts at glutamate receptor subtypes to evoked Ca2+ transients; and 4. The magnitude of glutamate-evoked Ca2+ responses increases in the setting of peripheral neuropathic pain. Results Bath-applied glutamate robustly increased [Ca2+]i in 14.4 ± 2.6 cells per dorsal horn within a 440 x 330 um field-of-view, with an average time-to-peak of 27 s and decay of 112 s. Repeated application produced sequential responses of similar magnitude, indicating the absence of sensitization, desensitization or tachyphylaxis. Ca2+ transients were glutamate concentration-dependent with a Kd = 0.64 mM. Ca2+ responses predominantly occurred on neurons since: 1 Over 95% of glutamate-responsive cells did not label with the astrocyte marker, SR-101; 2 62% of fura-2 AM loaded cells exhibited spontaneous action potentials; 3 75% of cells that responded to locally-applied glutamate with a rise in [Ca2+]i also showed a significant increase in AP frequency upon a subsequent glutamate exposure; 4 In experiments using simultaneous on-cell recordings and Ca2+ imaging, glutamate elicited a Ca2+ response and an increase in AP frequency. AMPA/kainate (CNQX- and AMPA (GYKI 52466-selective receptor antagonists significantly attenuated glutamate-evoked increases in [Ca2+]i, while NMDA (AP-5, kainate (UBP-301 and class I mGluRs (AIDA did not. Compared to sham controls, peripheral nerve injury

  1. The study on the targets of the optical evoked auditory brainstem response on the cochlea of guinea pig stimulating by infrared laser%红外线激光刺激豚鼠耳蜗诱发听性脑干反应作用靶点的实验研究

    Institute of Scientific and Technical Information of China (English)

    谢冰斌; 李华伟; 戴春富


    Objective To identify the targets of the infrared laser stimulating on the cochlea of guinea pig which evoked auditory brainstem response (oABR),and explore the mechanisms of the infrared neurostimulation.Methods A polished optical fiber with 200 μm diameter (NA =0.22) was planted into the scala tympani of guinea pigs to stimulate the cochlea of both the normal hearing and acute deafened guinea pigs.The direction of the fiber distal was changed to radiate different regions of the scala tympani,recording the oABR respectively.Differences of energy thresholds and amplitudes of oABR between normal hearing and acute deafened animals was concerned,and different responses were recorded as the optical path of laser fiber being changed to investigate the targets of the infrared laser stimulation.Immunofluorescence was used to detect the changes of inner and outer hair cells,and spiral ganglion neurons 7 days postdeafening,to looking for the probable association with the oABR changes at the same stimulus.SPSS 18.0 software was used to analyze the data.Results Inner and outer hair cells were damaged in basal and middle turn,butresidual hair cells were observed in apical turn.Only when the optical fiber pointed to Rosenthal's canal stimulated the spiral ganglion region directly could the oABR be evoked.No response was recorded while the fiber pointed to other directions.Conclusion Infrared laser stimulates cochlea evoked oABR generats from the response of spiral ganglion directly,the spiral ganglion neurons are the target of infrared stimulation.%目的 研究红外线激光刺激豚鼠耳蜗诱发听性脑干反应(optical evoled auditory brainstem response,oABR)的作用靶点,探讨激光刺激的作用机制.方法 对正常听力豚鼠及急性耳蜗损伤豚鼠耳蜗植入直径200μm的光纤(NA =0.22),光纤末端对准鼓阶不同部位进行激光刺激,记录并比较不同刺激角度下oABR的反应情况及正常听力与急性耳蜗损伤豚鼠oABR阈值和

  2. Persistent cue-evoked activity of accumbens neurons after prolonged abstinence from self-administered cocaine. (United States)

    Ghitza, Udi E; Fabbricatore, Anthony T; Prokopenko, Volodymyr; Pawlak, Anthony P; West, Mark O


    Persistent neural processing of information regarding drug-predictive environmental stimuli may be involved in motivating drug abusers to engage in drug seeking after abstinence. The addictive effects of various drugs depend on the mesocorticolimbic dopamine system innervating the nucleus accumbens. We used single-unit recording in rats to test whether accumbens neurons exhibit responses to a discriminative stimulus (SD) tone previously paired with cocaine availability during cocaine self-administration. Presentation of the tone after 3-4 weeks of abstinence resulted in a cue-induced relapse of drug seeking under extinction conditions. Accumbens neurons did not exhibit tone-evoked activity before cocaine self-administration training but exhibited significant SD tone-evoked activity during extinction. Under extinction conditions, shell neurons exhibited significantly greater activity evoked by the SD tone than that evoked by a neutral tone (i.e., never paired with reinforcement). In contrast, core neurons responded indiscriminately to presentations of the SD tone or the neutral tone. Accumbens shell neurons exhibited significantly greater SD tone-evoked activity than did accumbens core neurons. Although the onset of SD tone-evoked activity occurred well before the earliest movements commenced (150 msec), this activity often persisted beyond the onset of tone-evoked movements. These results indicate that accumbens shell neurons exhibit persistent processing of information regarding reward-related stimuli after prolonged drug abstinence. Moreover, the accumbens shell appears to be involved in discriminating the motivational value of reward-related associative stimuli, whereas the accumbens core does not.

  3. Brainstem evoked response in bus drivers with noise-induced hearing loss Audiometria de tronco encefálico em motoristas de ônibus com perda auditiva induzida pelo ruído

    Directory of Open Access Journals (Sweden)

    Adriana Silveira Santos


    Full Text Available Studies carried out by Brainstem Evoked Auditory Potentials (BEAP in Noise-Induced Hearing Loss (NIHL workers show different results in relation to neuronal involvement, not involving bus drivers as study object. AIM: to use BEAP in a prospective case/control clinical study to check whether or not there is neural auditory pathway involvement in bus drivers with NIHL. MATERIALS AND METHODS: we selected 50 bus drivers between 27 and 40 years with mild to moderate NIHL, and 20 individuals between 29 and 40 years with normal hearing and without prior history of noise exposure. BEAP tests were carried out and the traces were analyzed. RESULTS: in the NIHL group, the auditory thresholds in 3, 4 and 6 kHz were significantly higher in the left ear. In the NIHL group, potentials PI, PIII and/or PV were not present in a small number of the individuals; we observed a statistically significant increase in PI, PIII and PV absolute latencies, (LIP LIP I-III interpeak latencies, bilaterally and LIP I-V in the left ear. CONCLUSION: in the NIHL group, besides sensorial injury, changes in BEAP latencies suggest an early functional injury of the first auditory pathway afferent neuron.Estudos realizados com os Potenciais Auditivos Evocados de Tronco Encefálico (PEATE em trabalhadores com Perda Auditiva Induzida pelo Ruído (PAIR apresentam resultados díspares em relação ao comprometimento neuronal, além de não contemplar motoristas de ônibus como objeto de estudo. OBJETIVO: Avaliar pelo PEATE, em estudo clínico de série caso/controle, prospectivo, se há comprometimento das vias auditivas neurais em motoristas de ônibus com PAIR. MATERIAL E MÉTODO: Foram selecionados 50 motoristas de ônibus entre 27 e 40 anos portadores de PAIR leve a moderada; e 20 sujeitos entre 29 e 40 anos com audibilidade normal e sem antecedentes de exposição a ruído. Os PEATEs foram realizados e os traçados analisados. RESULTADOS: No grupo PAIR, os limiares auditivos em 3, 4


    Institute of Scientific and Technical Information of China (English)

    管宇宙; 崔丽英; 汤晓芙; 李本红; 杜华


    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatusensory evoked potentials(SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 norreal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2. 1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnet-ic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and ampli-tude (P38 - N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amphtudes of cerebral evoked potentials by magnetic stimulation of calf mus-cle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2. 9 ± 2. 1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged ( P < 0. 01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients. Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  5. Video Outside Versus Video Inside the Web: Do Media Setting and Image Size Have an Impact on the Emotion-Evoking Potential of Video? (United States)

    Verleur, Ria; Verhagen, Plon W.

    To explore the educational potential of video-evoked affective responses in a Web-based environment, the question was raised whether video in a Web-based environment is experienced differently from video in a traditional context. An experiment was conducted that studied the affect-evoking power of video segments in a window on a computer screen…

  6. Thought-evoking approaches in engineering problems

    CERN Document Server


    In creating the value-added product in not distant future, it is necessary and inevitable to establish a holistic and though-evoking approach to the engineering problem, which should be at least associated with the inter-disciplinary knowledge and thought processes across the whole engineering spheres. It is furthermore desirable to integrate it with trans-disciplinary aspects ranging from manufacturing culture, through liberal-arts engineering, and industrial sociology.   The thought-evoking approach can be exemplified and typified by representative engineering problems: unveiling essential features in ‘Tangential Force Ratio and Interface Pressure’, prototype development for ‘Bio-mimetic Needle’ and application of ‘Water-jet Machining to Artificial Hip Joint’, product innovation in ‘Heat Sink for Computer’, application of ‘Graph Theory’ to similarity evaluation of production systems, leverage among reciprocity attributes in ‘Industrial and Engineering Designs for Machine Enclosure’,...

  7. Early visual evoked potentials in callosal agenesis. (United States)

    Barr, Melodie S; Hamm, Jeff P; Kirk, Ian J; Corballis, Michael C


    Three participants with callosal agenesis and 12 neurologically normal participants were tested on a simple reaction time task, with visual evoked potentials collected using a high-density 128-channel system. Independent-components analyses were performed on the averaged visual evoked potentials to isolate the components of interest. Contrary to previous research with acallosals, evidence of ipsilateral activation was present in all 3 participants. Although ipsilateral visual components were present in all 4 unilateral conditions in the 2 related acallosal participants, in the 3rd, these were present only in the crossed visual field-hand conditions and not in the uncrossed conditions. Suggestions are made as to why these results differ from earlier findings and as to the neural mechanisms facilitating this ipsilateral activation.

  8. Changes of brainstem auditory and somatosensory evoked

    Institute of Scientific and Technical Information of China (English)

    Yang Jian


    Objective: to investigate the characteristics and clinical value of evoked potentials in late infantile form of metachromatic leukodystrophy. Methods: Brainstem auditory, and somatosensory evoked potentials were recorded in 6 patients, and compared with the results of CT scan. Results: All of the 6 patients had abnormal results of BAEP and MNSEP. The main abnormal parameters in BAEP were latency prolongation in wave I, inter-peak latency prolongation in Ⅰ-Ⅲ and Ⅰ-Ⅴ. The abnormal features of MNSEP were low amplitude and absence of wave N9, inter-Peak latency prolongation in Ng-N13 and N13-N20, but no significant change of N20 amplitude. The results also revealed that abnormal changes in BAEP and MNSEP were earlier than that in CT. Conclusion: The detection of BAEP and MNSEP in late infantile form of metachromatic leukodystrophy might early reveal the abnormality of conductive function in nervous system and might be a useful method in diagnosis.

  9. What reported food-evoked emotions may add: A model to predict consumer food choice

    NARCIS (Netherlands)

    Gutjar, S.; Dalenberg, J.R.; Graaf, de C.; Wijk, de R.A.; Palascha, A.; Renken, Remco J.; Jager, G.


    Food-evoked emotions provide information that goes beyond the information from traditional hedonic ratings. The objectives of our study were: (i) to investigate how intrinsic (sensory) and extrinsic (packaging) cues affect consumers’ emotional responses to foods, and (ii) to explore whether emotiona

  10. The analysis of multiple habituation profiles of single trial evoked potentials

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Roelofs, J.W.


    Presents a new statistical technique for analyzing multiple habituation profiles of single-trial evoked potentials (EPs). The method is based on a model of the essential characteristics of the habituation process--trial-dependent modulation of amplitude and phase of the underlying brain responses to

  11. [Intraoperative monitoring: visual evoked potentials in surgery of the sellar region]. (United States)

    Lorenz, M; Renella, R R


    During 18 sellar and perisellar operations the optic tract was monitored by visual evoked potentials (VEP). Deteriorations of the cortical responses were recorded in 73%. In this patients there was no close correlation between the intraoperative findings and the postoperative visual function. Only in those patients who showed no remarkable intraoperative changes VEP seemed to be of reliable prognostic value.

  12. What reported food-evoked emotions may add : A model to predict consumer food choice

    NARCIS (Netherlands)

    Gutjar, Swetlana; Dalenberg, Jelle R.; de Graaf, Cees; de Wijk, Rene A.; Palascha, Aikaterini; Renken, Remco J.; Jager, Gerry


    Food-evoked emotions provide information that goes beyond the information from traditional hedonic ratings. The objectives of our study were: (i) to investigate how intrinsic (sensory) and extrinsic (packaging) cues affect consumers' emotional responses to foods, and (ii) to explore whether emotiona

  13. Comparison of the pattern reversal visual evoked potential mediated by separate cone systems

    DEFF Research Database (Denmark)

    Johnsen, B; Frederiksen, J.L.; Larsson, H.B.


    With the purpose of recording responses mediated by the 3 cone systems visual evoked potentials (VEPs) were elicited by the reversal of monochromatic checkerboards superimposed upon strong monochromatic backgrounds (yellow, purple and blue-green). The sensitivity to light of various wave lengths...

  14. Evoked Effective Connectivity of the Human Neocortex


    Entz, László; Tóth, Emília; Keller, Corey J.; Bickel, Stephan; Groppe, David M.; Fabó, Dániel; Kozák, Lajos R.; Eroőss, Loránd; Ulbert, István; Mehta, Ashesh D.


    The role of cortical connectivity in brain function and pathology is increasingly being recognized. While in vivo magnetic resonance imaging studies have provided important insights into anatomical and functional connectivity, these methodologies are limited in their ability to detect electrophysiological activity and the causal relationships that underlie effective connectivity. Here, we describe results of cortico-cortical evoked potential (CCEP) mapping using single pulse electrical stimul...

  15. Auditory evoked potentials and multiple sclerosis


    Carla Gentile Matas; Sandro Luiz de Andrade Matas; Caroline Rondina Salzano de Oliveira; Isabela Crivellaro Gonçalves


    Multiple sclerosis (MS) is an inflammatory, demyelinating disease that can affect several areas of the central nervous system. Damage along the auditory pathway can alter its integrity significantly. Therefore, it is important to investigate the auditory pathway, from the brainstem to the cortex, in individuals with MS. OBJECTIVE: The aim of this study was to characterize auditory evoked potentials in adults with MS of the remittent-recurrent type. METHOD: The study comprised 25 individuals w...

  16. Contact Heat Evoked Potentials (CHEPs) in Patients with Mild-Moderate Alzheimer's Disease and Matched Control

    DEFF Research Database (Denmark)

    Jensen-Dahm, Christina; Madsen, Caspar Skau; Waldemar, Gunhild


    OBJECTIVE: Clinical studies have found that patients with Alzheimer's disease report pain of less intensity and with a lower affective response, which has been thought to be due to altered pain processing. The authors wished to examine the cerebral processing of non-painful and painful stimuli...... using somatosensory evoked potentials and contact heat evoked potentials in patients with Alzheimer's disease and in healthy elderly controls. DESIGN: Case-control study SETTING AND SUBJECTS: Twenty outpatients with mild-moderate Alzheimer's disease and in 17 age- and gender-matched healthy controls...... threshold and heat pain threshold. Somatosensory evoked potentials, amplitude, and latency were within normal range and similar for the two groups. CONCLUSIONS: The findings suggest that the processing of non-painful and painful stimuli is preserved in patients with mild to moderate Alzheimer's disease....

  17. Quantifying the effect of isoflurane and nitrous oxide on somatosensory-evoked potentials

    Directory of Open Access Journals (Sweden)

    Usha Devadoss


    Full Text Available Anaesthetic techniques may have a significant effect on intraoperative-evoked potentials (EP. The present study is designed to compare Propofol anaesthesia with Isoflurane (with or without nitrous oxide during intraoperative somatosensory-evoked potential (SSEP monitoring in 15 ASA Grade I and II patients undergoing surgery for intracranial tumours. SSEPs in response to median and posterior tibial nerve stimulation were recorded under four different anaesthetic conditions: 1 Propofol infusion and ventilation with air-oxygen, 2 Isoflurane, 1.0 MAC and ventilation with air-oxygen, 3 Isoflurane 1.0 MAC and ventilation with nitrous oxide-oxygen, and 4 Return to Isoflurane, 1.0 MAC and ventilation with air-oxygen. Intraoperative monitoring of somatosensory evoked potentials is best recordable using Propofol. The morphology of the EP is reproducible with Isoflurane. This effect is exaggerated when it is advisable to avoid nitrous oxide.

  18. Effect of mechanical tactile noise on amplitude of visual evoked potentials: multisensory stochastic resonance. (United States)

    Méndez-Balbuena, Ignacio; Huidobro, Nayeli; Silva, Mayte; Flores, Amira; Trenado, Carlos; Quintanar, Luis; Arias-Carrión, Oscar; Kristeva, Rumyana; Manjarrez, Elias


    The present investigation documents the electrophysiological occurrence of multisensory stochastic resonance in the human visual pathway elicited by tactile noise. We define multisensory stochastic resonance of brain evoked potentials as the phenomenon in which an intermediate level of input noise of one sensory modality enhances the brain evoked response of another sensory modality. Here we examined this phenomenon in visual evoked potentials (VEPs) modulated by the addition of tactile noise. Specifically, we examined whether a particular level of mechanical Gaussian noise applied to the index finger can improve the amplitude of the VEP. We compared the amplitude of the positive P100 VEP component between zero noise (ZN), optimal noise (ON), and high mechanical noise (HN). The data disclosed an inverted U-like graph for all the subjects, thus demonstrating the occurrence of a multisensory stochastic resonance in the P100 VEP.

  19. Subcortical evoked activity and motor enhancement in Parkinson's disease (United States)

    Anzak, Anam; Tan, Huiling; Pogosyan, Alek; Khan, Sadaquate; Javed, Shazia; Gill, Steven S.; Ashkan, Keyoumars; Akram, Harith; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Green, Alexander L.; Aziz, Tipu; Brown, Peter


    Enhancements in motor performance have been demonstrated in response to intense stimuli both in healthy subjects and in the form of ‘paradoxical kinesis’ in patients with Parkinson's disease. Here we identify a mid-latency evoked potential in local field potential recordings from the region of the subthalamic nucleus, which scales in amplitude with both the intensity of the stimulus delivered and corresponding enhancements in biomechanical measures of maximal handgrips, independent of the dopaminergic state of our subjects with Parkinson's disease. Recordings of a similar evoked potential in the related pedunculopontine nucleus – a key component of the reticular activating system – provide support for this neural signature in the subthalmic nucleus being a novel correlate of ascending arousal, propagated from the reticular activating system to exert an ‘energizing’ influence on motor circuitry. Future manipulation of this system linking arousal and motor performance may provide a novel approach for the non-dopaminergic enhancement of motor performance in patients with hypokinetic disorders such as Parkinson's disease. PMID:26687971

  20. Contrast independence of dynamic random dot correlogram evoked VEP amplitude. (United States)

    Markó, Katalin; Kiss, Huba J M; Mikó-Baráth, Eszter; Bártfai, Orsolya; Török, Béla; Kovács, Ilona; Jandó, Gábor


    Dynamic random dot correlograms (DRDCs) are binocular stimuli that evoke a percept and a visual evoked potential (VEP) only in case of a mature and functional binocular system. DRDC-VEP is a method extensively used to study cortical binocularity in human infants and nonverbal children. Although the DRDC-VEP was invented 3 decades ago, neither the fundamental parameters, including contrast, of the stimulation nor the cerebral processing mechanisms have been clarified. The objective of the present study was to investigate the variability and detectability of adults' VEPs to DRDC under different stimulus contrast conditions. DRDCs were presented on the red and green channels of a computer monitor and were viewed with red-green goggles. The steady state DRDC-VEPs were recorded in healthy adult volunteers, and response reliability was assessed by the T(circ)(2) statistic. DRDC-VEP amplitude was independent of contrast, while VEP phases showed a weak correlation with contrast. Contrast invariance of DRDC-VEP amplitude suggests a very high contrast gain and dominant magnocellular input to the binocular correlation processing system.

  1. Evaluation of otoacoustic emissions and auditory brainstem responses for hearing screening of high risk infants

    Directory of Open Access Journals (Sweden)

    Tania Nazir


    Full Text Available Aim: The objective of the present study is the assessment of otoacoustic emissions (OAEs and auditory brainstem responses (ABRs for hearing screening of high risk infants. Study Design: Prospective, hospital-based. Materials and Methods: Distortion product OAEs (DPOAEs and brainstem evoked response audiometry (BERA recordings were obtained for 30 controls and 100 infants with one or more high risk factors, in a sound treated room and the results were interpreted. ABR peak latencies, amplitudes, and waveform morphology in high risk infants were compared with those in control group. DPOAE as screening test was evaluated in terms of various parameters with BERA/ABR taken as gold standard. Results: Absolute latencies of Wave I and Wave V and interpeak latency of I-V were significantly prolonged in high risk group as compared to control group. The most common causes to contribute significantly for hearing impairment were found to be hyperbilirubinemia, birth asphyxia, meningitis/septicemia. DPOAE when compared with ABR taken as gold standard showed that sensitivity of the test was 87.7% (74.5%-94.9% and specificity was 74.5% (60.0%-85.2%. Positive predictive value was 76.7% (63.2%-86.6% and negative predictive value of the test was 86% (71.9%-94.3%. Positive likelihood ratio was 0.29 (0.18-0.46 and negative likelihood ratio was 6.08 (2.82-13.09. Conclusion : ABR/BERA, though highly reliable, is a tedious and time consuming test. DPOAE is a simple and rapid test with relatively higher acceptability but low sensitivity and specificity; therefore, limits its role as independent screening test. DPOAE-ABR test series is an effective way to screen all the high risk infants at the earliest.

  2. Three-year experience with the Sophono in children with congenital conductive unilateral hearing loss: tolerability, audiometry, and sound localization compared to a bone-anchored hearing aid. (United States)

    Nelissen, Rik C; Agterberg, Martijn J H; Hol, Myrthe K S; Snik, Ad F M


    Bone conduction devices (BCDs) are advocated as an amplification option for patients with congenital conductive unilateral hearing loss (UHL), while other treatment options could also be considered. The current study compared a transcutaneous BCD (Sophono) with a percutaneous BCD (bone-anchored hearing aid, BAHA) in 12 children with congenital conductive UHL. Tolerability, audiometry, and sound localization abilities with both types of BCD were studied retrospectively. The mean follow-up was 3.6 years for the Sophono users (n = 6) and 4.7 years for the BAHA users (n = 6). In each group, two patients had stopped using their BCD. Tolerability was favorable for the Sophono. Aided thresholds with the Sophono were unsatisfactory, as they did not reach under a mean pure tone average of 30 dB HL. Sound localization generally improved with both the Sophono and the BAHA, although localization abilities did not reach the level of normal hearing children. These findings, together with previously reported outcomes, are important to take into account when counseling patients and their caretakers. The selection of a suitable amplification option should always be made deliberately and on individual basis for each patient in this diverse group of children with congenital conductive UHL.

  3. Auditory- and visual-evoked potentials in Mexican infants are not affected by maternal supplementation with 400 mg/d docosahexaenoic acid in the second half of pregnancy. (United States)

    Stein, Aryeh D; Wang, Meng; Rivera, Juan A; Martorell, Reynaldo; Ramakrishnan, Usha


    The evidence relating prenatal supplementation with DHA to offspring neurological development is limited. We investigated the effect of prenatal DHA supplementation on infant brainstem auditory-evoked responses and visual- evoked potentials in a double-blind, randomized controlled trial in Cuernavaca, Mexico. Pregnant women were supplemented daily with 400 mg DHA or placebo from gestation wk 18-22 through delivery. DHA and placebo groups did not differ in maternal characteristics at randomization or infant characteristics at birth. Brainstem auditory-evoked responses were measured at 1 and 3 mo in 749 and 664 infants, respectively, and visual-evoked potentials were measured at 3 and 6 mo in 679 and 817 infants, respectively. Left-right brainstem auditory-evoked potentials were moderately correlated (range, 0.26-0.43; all P evoked potentials were strongly correlated (range, 0.79-0.94; all P 0.10). We conclude that DHA supplementation during pregnancy did not influence brainstem auditory-evoked responses at 1 and 3 mo or visual-evoked potentials at 3 and 6 mo.

  4. DMPP-evoked increases in postganglionic sympathetic nerve activity and blood pressure occurs by two mechanisms in the rat. (United States)

    Martin, J R


    1. Intravenous administration of the ganglionic nicotinic receptor agonist DMPP (1,1-dimethyl-4-phenylpiperazinium iodide) into urethane-anaesthetized rats evoked dose-dependent increases in mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA). 2. The ganglionic nicotinic receptor antagonists pentolinium and hexamethonium either alone or combined did not inhibit the increase in RSNA and MAP evoked by 50 to 200 micrograms kg-1 doses of DMPP. The increase in renal sympathetic nerve activity evoked by DMPP occurred as a brief burst in firing. 3. The increase in MAP, but not RSNA, evoked by DMPP in the presence of pentolinium was inhibited by the selective alpha 1-adrenergic receptor antagonist prazosin. 4. The non-selective alpha-adrenoceptor and NPY receptor antagonist benextramine also inhibited the increase in MAP without inhibiting the increase in RSNA. Surprisingly, the combination of benextramine and pentolinium, or benextramine and hexamethonium, completely blocked the DMPP-evoked increase in RSNA and thus the increase in MAP. 5. The uptake1 antagonist desipramine combined with pentolinium did not affect the DMPP-evoked increases in MAP or RSNA when compared to the responses evoked in the presence of pentolinium alone. 6. Adding the selective M1 muscarinic receptor antagonist telenzepine to pentolinium and prazosin did not inhibit the increase in RSNA evoked by a 100 micrograms kg-1 dose of DMPP. 7. While the DMPP-evoked increase in MAP in the presence of ganglionic nicotinic receptor antagonists is primarily dependent upon activation of alpha 1-adrenoceptors, the increase in RSNA occurs via activation of ganglionic nicotinic receptors and activation of a mechanism susceptible to blockade by benextramine.

  5. Cervical vestibular evoked myogenic potentials and caloric test results in individuals with auditory neuropathy spectrum disorders. (United States)

    Sujeet, Kumar Sinha; Niraj, Kumar Singh; Animesh, Barman; Rajeshwari, G; Sharanya, R


    Auditory neuropathy spectrum disorder is a type of hearing loss where outer hair cell function are normal (as evidenced by the preservation of OAEs and cochlear microphonics), whereas auditory nerve functions are abnormal (as evidenced by abnormal auditory brainstem evoked potentials beginning with wave I of the ABR) and acoustic reflexes to ipsilateral and contralateral tones are absent. It is likely that in cases with auditory neuropathy spectrum disorder not only the cochlear nerve, but also the vestibular nerves might get involved. The present study was conducted with an aim of finding out the inferior and superior vestibular nerve involvement through cervical vestibular evoked myogenic potentials and Caloric test results respectively in individuals with Auditory Neuropathy Spectrum Disorders. Total 26 participants who fulfilled the criteria of auditory neuropathy spectrum disorder participated for the study. Vestibular evoked myogenic potentials results showed absence of responses from most of the subjects also caloric responses showed bilateral hypofunctional responses in most of the participants, which is suggestive of involvement of both the inferior as well as superior vestibular nerve in individuals with auditory neuropathy spectrum disorders. Additionally there was no association between the pattern and degree of hearing loss to caloric test results and vestibular evoked myogenic potentials results findings.

  6. The Single Training Sample Extraction of Visual Evoked Potentials Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    LIU Fang; ZHANG Zhen; CHEN Wen-chao; QIN Bing


    Abstract.Based on the good localization characteristic of the wavelet transform both in time and frequency domain, a de-noising method based on wavelet transform is presented, which can make the extraction of visual evoked potentials in single training sample from the EEG background noise in favor of studying the changes between the single sample response happen. The information is probably related with the different function, appearance and pathologies of the brain. At the same time this method can also be used to remove those signal' s artifacts that do not appear with EP within the same scope of time or frequency. The traditional Fourier filter can hardly attain the similar result. This method is different from other wavelet de-noising methods in which different criteria are employed in choosing wavelet coefficient. It has a biggest virtue of noting the differences among the single training sample and making use of the characteristics of high time frequency resolution to reduce the effect of interference factors to a maximum extent within the time scope that EP appear. The experiment result proves that this method is not restricted by the signal-tonoise ratio of evoked potential and electroencephalograph (EEG) and even can recognize instantaneous event under the condition of lower signal-to-noise ratio, as well as recognize the samples which evoked evident response more easily. Therefore, more evident average evoked response could be achieved by de-nosing the signals obtained through averaging out the samples that can evoke evident responses than de-nosing the average of original signals. In addition, averaging methodology can dramatically reduce the number of record samples needed, thus avoiding the effect of behavior change during the recording process.This methodology pays attention to the differences among single training sample and also accomplishes the extraction of visual evoked potentials from single trainings sample. As a result, system speed and

  7. Endogenous attention signals evoked by threshold contrast detection in human superior colliculus. (United States)

    Katyal, Sucharit; Ress, David


    Human superior colliculus (SC) responds in a retinotopically selective manner when attention is deployed on a high-contrast visual stimulus using a discrimination task. To further elucidate the role of SC in endogenous visual attention, high-resolution fMRI was used to demonstrate that SC also exhibits a retinotopically selective response for covert attention in the absence of significant visual stimulation using a threshold-contrast detection task. SC neurons have a laminar organization according to their function, with visually responsive neurons present in the superficial layers and visuomotor neurons in the intermediate layers. The results show that the response evoked by the threshold-contrast detection task is significantly deeper than the response evoked by the high-contrast speed discrimination task, reflecting a functional dissociation of the attentional enhancement of visuomotor and visual neurons, respectively. Such a functional dissociation of attention within SC laminae provides a subcortical basis for the oculomotor theory of attention.

  8. GABAA receptors modulate cannabinoid-evoked hypothermia. (United States)

    Rawls, S M; Tallarida, R J; Kon, D A; Geller, E B; Adler, Martin W


    Cannabinoids evoke hypothermia by stimulating central CB(1) receptors. GABA induces hypothermia via GABA(A) or GABA(B) receptor activation. CB(1) receptor activation increases GABA release in the hypothalamus, a central locus for thermoregulation, suggesting that cannabinoid and GABA systems may be functionally linked in body temperature regulation. We investigated whether GABA receptors modulate the hypothermic actions of [4,5-dihydro-2-methyl-4(4-morpholinylmethyl)-1-(1-naphthalenyl-carbonyl)-6H-pyrrolo[3,2,1ij]quinolin-6-one] (WIN 55212-2), a selective cannabinoid agonist, in male Sprague-Dawley rats. WIN 55212-2 (2.5 mg/kg im) produced a rapid hypothermia that peaked 45-90 min postinjection. The hypothermia was attenuated by bicuculline (2 mg/kg ip), a GABA(A) antagonist. However, SCH 50911 (1-10 mg/kg ip), a GABA(B) blocker, did not antagonize the hypothermia. Neither bicuculline (2 mg/kg) nor SCH 50911 (10 mg/kg) by itself altered body temperature. We also investigated a possible role for CB(1) receptors in GABA-generated hypothermia. Muscimol (2.5 mg/kg ip), a GABA(A) agonist, or baclofen (5 mg/kg ip), a GABA(B) agonist, evoked a significant hypothermia. Blockade of CB(1) receptors with SR141716A (2.5 mg/kg im) did not antagonize muscimol- or baclofen-induced hypothermia, indicating that GABA-evoked hypothermia does not contain a CB(1)-sensitive component. Our results implicate GABA(A) receptors in the hypothermic actions of cannabinoids and provide further evidence of a functional link between cannabinoid and GABA systems.

  9. Evoked potentials in Guillain-Barré syndrome. (United States)

    Ropper, A H; Chiappa, K H


    We studied evoked potentials (EPs) in 27 patients with typical acute Guillain-Barré syndrome and 3 with Fisher's syndrome. Three of 21 had BAEP abnormalities: 1 with bilateral I-III, 1 with unilateral I-III, and another with unilateral III-V interwave latency prolongations. Three with Fisher's syndrome had normal BAEPs (one had a poorly formed wave V unilaterally with one click polarity only). Ten of 21 median nerve EPs and 9 of 12 peroneal or tibial nerve somatosensory EPs were abnormal. Seven patients with normal somatosensory EPs had abnormal F waves from the same nerve; none had normal late responses and abnormal somatosensory EPs. These observations differ from previous reports on the frequency and interpretation of EP abnormalities in Guillain-Barré syndrome.

  10. Spatial coincidence modulates interaction between visual and somatosensory evoked potentials. (United States)

    Schürmann, Martin; Kolev, Vasil; Menzel, Kristina; Yordanova, Juliana


    The time course of interaction between concurrently applied visual and somatosensory stimulation with respect to evoked potentials (EPs) was studied. Visual stimuli, either in the left or right hemifield, and electric stimuli to the left wrist were delivered either alone or simultaneously. Visual and somatosensory EPs were summed and compared to bimodal EPs (BiEP, response to actual combination of both modalities). Temporal coincidence of stimuli lead to sub-additive or over-additive amplitudes in BiEPs in several time windows between 75 and 275 ms. Additional effects of spatial coincidence (left wrist with left hemifield) were found between 75 and 300 ms and beyond 450 ms. These interaction effects hint at a temporo-spatial pattern of multiple brain areas participating in the process of multimodal integration.

  11. Visual evoked potentials and selective attention to points in space (United States)

    Van Voorhis, S.; Hillyard, S. A.


    Visual evoked potentials (VEPs) were recorded to sequences of flashes delivered to the right and left visual fields while subjects responded promptly to designated stimuli in one field at a time (focused attention), in both fields at once (divided attention), or to neither field (passive). Three stimulus schedules were used: the first was a replication of a previous study (Eason, Harter, and White, 1969) where left- and right-field flashes were delivered quasi-independently, while in the other two the flashes were delivered to the two fields in random order (Bernoulli sequence). VEPs to attended-field stimuli were enhanced at both occipital (O2) and central (Cz) recording sites under all stimulus sequences, but different components were affected at the two scalp sites. It was suggested that the VEP at O2 may reflect modality-specific processing events, while the response at Cz, like its auditory homologue, may index more general aspects of selective attention.

  12. Formalin evokes calcium transients from the endoplasmatic reticulum.

    Directory of Open Access Journals (Sweden)

    Michael J M Fischer

    Full Text Available The formalin test is the most widely used behavioral screening test for analgesic compounds. The cellular mechanism of action of formaldehyde, inducing a typically biphasic pain-related behavior in rodents is addressed in this study. The chemoreceptor channel TRPA1 was suggested as primary transducer, but the high concentrations used in the formalin test elicit a similar response in TRPA1 wildtype and knockout animals. Here we show that formaldehyde evokes a dose-dependent calcium release from intracellular stores in mouse sensory neurons and primary keratinocytes as well as in non-neuronal cell lines, and independent of TRPA1. The source of calcium is the endoplasmatic reticulum and inhibition of the sarco/endoplasmic reticulum calcium-ATPase has a major contribution. This TRPA1-independent mechanism may underlie formaldehyde-induced pan-neuronal excitation and subsequent inflammation.

  13. Visual evoked potentials in neuromyelitis optica and its spectrum disorders. (United States)

    Ringelstein, Marius; Kleiter, Ingo; Ayzenberg, Ilya; Borisow, Nadja; Paul, Friedemann; Ruprecht, Klemens; Kraemer, Markus; Cohn, Eva; Wildemann, Brigitte; Jarius, Sven; Hartung, Hans-Peter; Aktas, Orhan; Albrecht, Philipp


    Optic neuritis (ON) is a key feature of neuromyelitis optica (NMO). Recently, NMO patients of predominantly Afro-Brazilian origin were evaluated by visual evoked potentials (VEPs) and showed marked amplitude reductions. Here, we analyzed VEPs in a predominantly Caucasian cohort, consisting of 43 patients with definite NMO, 18 with anti-aquaporin (AQP) 4 antibody-seropositive NMO spectrum disorders and 61 matched healthy controls. We found reduced amplitudes in only 12.3%, prolonged latencies in 41.9% and a lack of response in 14.0% of NMO eyes. Delayed P100 latencies in eyes without prior ON suggested this was a subclinical affection. The data indicate heterogenous patterns in NMO, warranting further investigation.

  14. Automatic denoising of single-trial evoked potentials. (United States)

    Ahmadi, Maryam; Quian Quiroga, Rodrigo


    We present an automatic denoising method based on the wavelet transform to obtain single trial evoked potentials. The method is based on the inter- and intra-scale variability of the wavelet coefficients and their deviations from baseline values. The performance of the method is tested with simulated event related potentials (ERPs) and with real visual and auditory ERPs. For the simulated data the presented method gives a significant improvement in the observation of single trial ERPs as well as in the estimation of their amplitudes and latencies, in comparison with a standard denoising technique (Donoho's thresholding) and in comparison with the noisy single trials. For the real data, the proposed method largely filters the spontaneous EEG activity, thus helping the identification of single trial visual and auditory ERPs. The proposed method provides a simple, automatic and fast tool that allows the study of single trial responses and their correlations with behavior.

  15. Effects of spatial frequency on visual evoked magnetic fields. (United States)

    Tsuruhara, Aki; Nagata, Yuko; Suzuki, Masaya; Inui, Koji; Kakigi, Ryusuke


    Psychophysical and visual evoked potential (VEP) studies have shown that spatial frequency of a visual stimulus affects contrast sensitivity and VEPs in humans. However, it is not clear whether and how the effect of spatial frequency varies among cortical areas. Considering that all visual inputs to the retina could be expressed as a sum of sinusoidal gratings of different spatial frequencies, the effect of spatial frequency must be clarified to separate the brain activity specific to each visual stimulus. In order to examine the effect of spatial frequency on different cortical areas, the present study compared cortical responses to sinusoidal gratings of seven different spatial frequencies using magnetoencephalography (MEG). MEG waveforms of twelve healthy adults in response to sinusoidal gratings of 0.3-18.1 cycles per degree were subjected to a multi-dipole analysis. As a result, the effect of spatial frequency was significant on the first peak latency and amplitude of the source activity around V1 and V2 but not on the source activity around V3 and V6, indicating that the effect of spatial frequency varies across different visual areas in the human brain. Our results also suggest that the responses in V1 and V2 that have a peak around 90 ms and that of V6 peaking around 120 ms should be separated to investigate the stimulus-specific cortical response, particularly when examining effects of spatial frequency on the response latency.

  16. 味觉刺激引起大鼠臂旁核神经元抑制性反应%Inhibitory responses of parabrachial neurons evoked by taste stimuli in rat

    Institute of Scientific and Technical Information of China (English)

    雷琦; 闫剑群; 施京红; 杨雪娟; 陈坷


    In the present study, the responses of inhibitory gustatory neurons in the parabrachial nucleus (PBN) to four basic taste stimuli NaCl, HCl, quinine HCl (QHCl) and sucrose were examined using single-unit recording technique in anesthetized rats. A total of 18 inhibitory taste neurons in the PBN were obtained. Spontaneous firing rates of these inhibitory neurons were 0.2-5.5 Hz with mean firing rate of (2.15±0.31) Hz. Most of the neurons responded to more than one of the basic taste qualities. The inhibitory responses to taste occurred quickly and lasted 5-80 s in different PBN neurons. According to the responsive characteristics to the four basic taste stimuli, the neurons could be classified as NaCl-best (n=8), HCl-best (n=3), QHCl-best (n=3), and sucrose-best (n=4). The breadth of tuning of NaCl-best neurons was the highest (0.945). Inhibitory responsive neurons had feeble discrimination among sapid stimuli or aversive stimuli. These results suggest that there exist inhibitory taste neurons in the PBN. These neurons may play some useful roles in precise transmission of taste information and the taste coding for hedonic and aversive tastes.%本研究以轻度麻醉的大鼠为对象,应用细胞外微电极记录技术,观察并分析了脑桥臂旁核抑制性味觉神经元的自发活动及其对NaCl、HCl、盐酸奎宁(quinine HCl,QHCl))和蔗糖等四种基本味觉刺激的反应.共分析了18个具有自发活动的抑制性味觉神经元,自发放电频率分布在0.2~5.5Hz之间,平均放电频率(2.15±0.31) Hz.18个神经元中,1个神经元对单一味觉刺激呈抑制性反应,其余17个神经元对两种或两种以上的基本味觉刺激发生抑制性反应,且抑制具有潜伏期短、持续时间较长等特征.抑制持续时间5~80s,部分神经元表现为后抑制效应.根据神经元对四种基本味觉刺激呈抑制性反应的程度,将其分为NaCl优势神经元(n=8),HCl优势神经元(n=3),QHCl优势神经元(n=3)

  17. Lidocaine alters the input resistance and evokes neural activity in crayfish sensory neurons. (United States)

    Keceli, M B; Purali, N


    Lidocaine, a use-dependent Na(+) channel blocker, paradoxically evokes neural activation in the slowly adapting stretch receptor organ of crayfish at 5-10 mmol/l concentration. For elucidating the underlying mechanisms of this paradoxical effect, a series of conventional electrophysiological experiments were performed in the stretch receptor neurons of crayfish. In the presence of tetrodotoxin, lidocaine did not evoke impulse activity, however, a slowly developing and dose-dependent depolarization occurred in both the rapidly and slowly adapting stretch receptors. Similar effects were observed by perfusion of equivalent concentrations of benzocaine but not of procaine or prilocaine. Lidocaine did not evoke neural activity in the rapidly adapting neuron which fires action potential(s) in response to rapid changes in membrane potential. Slowly developing mode of the depolarization indicated the reason why only depolarization but not action potential responses were observed in the rapidly adapting neuron. The depolarizing effect of lidocaine was independent from any ionic channel or exchanger system. However, lidocaine and benzocaine but not procaine and prilocaine evoked a dose-dependent alteration in the input resistance of the neuron. It was proposed that the principal mechanism of the effect could stem from a change in the physical properties of the neuronal membrane.

  18. Diagnostic accuracy of evoked potentials for functional impairment after contusive spinal cord injury in adult rats. (United States)

    Thirumala, Parthasarathy; Zhou, James; Krishnan, Rohan; Manem, Nihita; Umredkar, Shreya; Hamilton, D K; Balzer, Jeffrey R; Oudega, Martin


    Iatrogenic spinal cord injury (SCI) is a cause of potentially debilitating post-operative neurologic complications. Currently, intra-operative neurophysiological monitoring (IONM) via somatosensory evoked potentials and motor-evoked potentials is used to detect and prevent impending SCI. However, no empirically validated interventions exist to halt the progression of iatrogenic SCI once it is detected. This is in part due to the lack of a suitable translational model that mimics the circumstances surrounding iatrogenic SCI detected via IONM. Here, we evaluate a model of simulated contusive iatrogenic SCI detected via IONM in adult female Sprague-Dawley rats. We show that transient losses of somatosensory evoked potentials responses are 88.24% sensitive (95% confidence interval [CI] 63.53-98.20) and 80% specific (95% CI 51.91-95.43) for significant functional impairment following simulated iatrogenic SCI. Similarly, we show that transient losses in motor-evoked potentials responses are 70.83% sensitive (95% CI 48.91-87.33) and 100% specific (95% CI 62.91-100.00) for significant functional impairment following simulated iatrogenic SCI. These results indicate that our model is a suitable replica of the circumstances surrounding clinical iatrogenic SCI.

  19. Efficacy of electrical stimulation of retinal ganglion cells with temporal patterns resembling light-evoked spike trains. (United States)

    Wong, Raymond C S; Garrett, David J; Grayden, David B; Ibbotson, Michael R; Cloherty, Shaun L


    People with degenerative retinal diseases such as retinitis pigmentosa lose most of their photoreceptors but retain a significant proportion (~30%) of their retinal ganglion cells (RGCs). Microelectronic retinal prostheses aim to bypass the lost photoreceptors and restore vision by directly stimulating the surviving RGCs. Here we investigate the extent to which electrical stimulation of RGCs can evoke neural spike trains with statistics resembling those of normal visually-evoked responses. Whole-cell patch clamp recordings were made from individual cat RGCs in vitro. We first recorded the responses of each cell to short sequences of visual stimulation. These responses were converted to trains of electrical stimulation that we then presented to the same cell via an epiretinal stimulating electrode. We then quantified the efficacy of the electrical stimuli and the latency of the evoked spikes. In all cases, spikes were evoked with sub-millisecond latency (0.55 ms, median, ON cells, n = 8; 0.75 ms, median, OFF cells, n = 6) and efficacy ranged from 0.4-1.0 (0.79, median, ON cells; 0.97, median, OFF cells). These data demonstrate that meaningful spike trains, resembling normal responses of RGCs to visual stimulation, can be reliably evoked by epiretinal prostheses.

  20. Interaural difference values of vestibular evoked myogenic.

    Directory of Open Access Journals (Sweden)

    Marziyeh Moallemi


    Full Text Available Migraine is a neurologic disease, which often is associated with a unilateral headache. Vestibular abnormalities are common in migraine. Vestibular evoked myogenic potentials (VEMPs assess otolith function in particular functional integrity of the saccule and the inferior vestibular nerve. We used VEMP to evaluate if the migraine headache can affect VEMP asymmetry parameters. A total of 25 patients with migraine (22 females and 3 males who were diagnosed according to the criteria of IHS-1988 were enrolled in this cross-sectional study. Control group consisted of 26 healthy participants (18 female and 8 male, without neurotological symptoms and history of migraine. The short tone burst (95 dB nHL, 500 Hz was presented to ears. VEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid (SCM muscle. Although current results showed that the amplitude ratio is greater in migraine patients than normal group, there was no statistical difference between two groups in mean asymmetry parameters of VEMP. Asymmetry measurements in vestibular evoked myogenic potentials probably are not indicators of unilateral deficient in saccular pathways of migraine patients.

  1. Evoked potentials in pediatric cerebral malaria

    Directory of Open Access Journals (Sweden)

    Minal Bhanushali


    Full Text Available Cortical evoked potentials (EP provide localized data regarding brain function and may offer prognostic information and insights into the pathologic mechanisms of malariamediated cerebral injury. As part of a prospective cohort study, we obtained somatosensory evoked potentials (SSEPs and brainstem auditory EPs (AEPs within 24 hours of admission on 27 consecutive children admitted with cerebral malaria (CM. Children underwent follow-up for 12 months to determine if they had any long term neurologic sequelae. EPs were obtained in 27 pediatric CM admissions. Two children died. Among survivors followed an average of 514 days, 7/25 (28.0% had at least one adverse neurologic outcome. Only a single subject had absent cortical EPs on admission and this child had a good neurologic outcome. Among pediatric CM survivors, cortical EPs are generally intact and do not predict adverse neurologic outcomes. Further study is needed to determine if alterations in cortical EPs can be used to predict a fatal outcome in CM.

  2. Long Latency Auditory Evoked Potentials during Meditation. (United States)

    Telles, Shirley; Deepeshwar, Singh; Naveen, Kalkuni Visweswaraiah; Pailoor, Subramanya


    The auditory sensory pathway has been studied in meditators, using midlatency and short latency auditory evoked potentials. The present study evaluated long latency auditory evoked potentials (LLAEPs) during meditation. Sixty male participants, aged between 18 and 31 years (group mean±SD, 20.5±3.8 years), were assessed in 4 mental states based on descriptions in the traditional texts. They were (a) random thinking, (b) nonmeditative focusing, (c) meditative focusing, and (d) meditation. The order of the sessions was randomly assigned. The LLAEP components studied were P1 (40-60 ms), N1 (75-115 ms), P2 (120-180 ms), and N2 (180-280 ms). For each component, the peak amplitude and peak latency were measured from the prestimulus baseline. There was significant decrease in the peak latency of the P2 component during and after meditation (Pmeditation facilitates the processing of information in the auditory association cortex, whereas the number of neurons recruited was smaller in random thinking and non-meditative focused thinking, at the level of the secondary auditory cortex, auditory association cortex and anterior cingulate cortex.

  3. The key role of sodium in the ouabain-mediated potentiation of potassium-evoked catecholamine release in cat adrenal glands.


    de Abajo, F. J.; Castro, M. A.; Sánchez-García, P.


    1. The effect of [Na]o on the catecholamine release evoked by K in ouabain pretreated, isolated adrenal glands of the cat, was investigated. 2. Reduction of [Na]o to 70, 50 and 25 mM, with sucrose as a substitute, did not modify the spontaneous catecholamine release but progressively increased the K (17.7 mM)-evoked secretory response. 3. Ouabain pretreatment (100 microM; 10 min) greatly increased the K (17.7 mM)-evoked catecholamine secretory response in glands perfused with normal Krebs. Su...

  4. Properties of rectified averaging of an evoked-type signal: theory and application to the vestibular-evoked myogenic potential. (United States)

    Colebatch, J G


    The properties of rectified averages were investigated using the VEMP (vestibular-evoked myogenic potential) as an example of an evoked-type response. Recordings were made of surface EMG from the sternocleidomastoid (SCM) muscles of six volunteers, unstimulated, at different levels of tonic activation and then in response to clicks of different intensities. The stochastic properties of the surface EMG recorded were shown to be well modelled using a zero mean normal distribution with a standard deviation equivalent to the mean RMS (root mean squared) value (mean residual error variance 0.87%). Assuming a normal distribution, equations were derived for the expected value of both the rectified and RMS average with the addition of constant waveforms of different sizes. A simulation using recorded EMG and added sine waves of different amplitudes demonstrated that the equations predicted the rectified averages accurately. It also confirmed the importance of the relative amplitude of the added signal in determining whether it was detected using rectified averages. The same equations were then applied to actual data consisting of VEMPs of different relative amplitudes recorded from the volunteers. Whilst the signal-to-noise ratio (measured by corrected amplitude) was a major determinant of the nature of the rectified average, consistent deviations were detected between the predicted and actual rectified averages. Deviations from predicted values indicated that the VEMP did not behave simply like a constant signal added to tonic background EMG. A more complicated model, which included temporal jitter as well as inhibition of background EMG during the VEMP, was required to fit the physiological recordings. Rectified averages are sensitive to physiological properties, which are not apparent when using unrectified averages alone. Awareness of the properties of rectified averages should improve their interpretation.

  5. Auditory evoked fields elicited by spectral, temporal, and spectral-temporal changes in human cerebral cortex

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    Hidehiko eOkamoto


    Full Text Available Natural sounds contain complex spectral components, which are temporally modulated as time-varying signals. Recent studies have suggested that the auditory system encodes spectral and temporal sound information differently. However, it remains unresolved how the human brain processes sounds containing both spectral and temporal changes. In the present study, we investigated human auditory evoked responses elicited by spectral, temporal, and spectral-temporal sound changes by means of magnetoencephalography (MEG. The auditory evoked responses elicited by the spectral-temporal change were very similar to those elicited by the spectral change, but those elicited by the temporal change were delayed by 30 – 50 ms and differed from the others in morphology. The results suggest that human brain responses corresponding to spectral sound changes precede those corresponding to temporal sound changes, even when the spectral and temporal changes occur simultaneously.

  6. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy


    Full Text Available Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years and 30 normal hearing individuals (mean age 24-27 years as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48% from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

  7. Estudo das latências e amplitudes dos potenciais evocados auditivos de média latência em indivíduos audiologicamente normais Middle latency response study of auditory evoked potentials’ amplitudes and lantencies audiologically normal individuals

    Directory of Open Access Journals (Sweden)

    Ivone Ferreira Neves


    Full Text Available Estudo de coorte contemporânea com corte transversal. O Potencial Evocado Auditivo de Média Latência (PEAML é gerado entre 10 e 80ms e possui múltiplos geradores, com maior contribuição da região tálamo-cortical. O estabelecimento de critérios de normalidade para os valores de latência e amplitude é necessário para uso clínico. OBJETIVOS: Analisar a latência e amplitude do PEAML em indivíduos sem alterações audiológicas, e verificar a confiabilidade da amplitude Pa-Nb. MATERIAL E MÉTODO: Foram coletados os PEAML de 25 indivíduos durante o ano de 2005 e analisados os componentes Na, Pa, Nb para cada orelha testada (A1 e A2, e posicionamento de eletrodo (C3 e C4. RESULTADOS: Observou-se diferença estatisticamente significante entre os valores médios de latência para C3A1 e C4A1 com relação aos componentes Na e Pa, não sendo encontrada esta diferença para o componente Nb e valores médios das amplitudes Na-Pa e Pa-Nb. CONCLUSÃO: Foram estabelecidos os valores das médias e desvios padrão para os parâmetros latência e amplitude dos componentes Na, Pa, Nb, e Na-Pa e Pa-Nb, nas condições C3A1, C4A1, C3A2, C4A2, proporcionando os parâmetros para a análise e interpretação deste potencial.Contemporary cohort cross-sectional study. Introduction: The auditory middle latency response (AMLR is generated between 10 and 80 ms and has multiple generators, with a greater contribution from the thalamus-cortical pathways. The establishment of normality criteria for latency and amplitude values is necessary for clinical use. AIM: to analyze the latency and amplitude of the AMLR in individuals without audiological disorders, and verify the reliability of Pa-Nb amplitude. MATERIALS AND METHODS: The AMLR of 25 individuals was collected during 2005 and the Na, Pa, Nb components were analyzed for each tested ear (A1 and A2, and electrode positioning (C3 and C4. RESULTS: A statistically significant difference was noticed among middle

  8. Hydrogen peroxide increases nerve-evoked contractions in mouse tail artery by an endothelium-dependent mechanism. (United States)

    Reardon, Trent F; Brock, James A


    Reactive oxygen species contribute to regulating the excitability of vascular smooth muscle. This study investigated the actions of the relatively stable reactive oxygen species, H(2)O(2), on nerve-evoked contractions of mouse distal tail artery. H(2)O(2) (10-100 μM) increased nerve-evoked contractions of isometrically mounted segments of tail artery. Endothelium denudation increased nerve-evoked contractions and abolished the facilitatory effect of H(2)O(2). Inhibition of nitric oxide synthase with L-nitroarginine methyl ester (0.1mM) also increased nerve-evoked contractions and reduced the late phase of H(2)O(2)-induced facilitation. H(2)O(2)-induced facilitation of nerve-evoked contractions depended, in part, on synthesis of prostanoids and was reduced by the cyclooxygenase inhibitor indomethacin (1 μM) and the thromboxane A(2) receptor antagonist SQ 29548 (1 μM). H(2)O(2) increased sensitivity of nerve-evoked contractions to the α(2)-adrenoceptor antagonist idazoxan (0.1 μM) but not to the α(1)-adrenoceptor antagonist prazosin (10nM). Idazoxan and the α(2C)-adrenoceptor antagonist JP 1302 (0.5-1 μM) reduced H(2)O(2)-induced facilitation. H(2)O(2) induced facilitation of nerve-evoked contractions was abolished by the non-selective cation channel blocker SKF-96365 (10 μM), suggesting it depends on Ca(2+) influx. In conclusion, H(2)O(2)-induced increases in nerve-evoked contractions depended on an intact endothelium and were mediated by activating thromboxane A(2) receptors and by increasing the contribution of α(2)-adrenoceptors to these responses.


    Institute of Scientific and Technical Information of China (English)

    肖泽萍; 陈兴时; 张明岛; 楼翡璎; 陈珏


    Objective To investigate the status of evoked potentials in obsessive-compulsive disorder (OCD). Methods Evoked potentials P300 , auditory brainstem response ( ABR ) and visual evoked potential (VEP) were recorded from 35 OCD patients and 28 normal controls (NC) with a Nicolet Spirit Instrument. 23 of the OCD patients were followed up after 5 months with the same markers. Results Compared with NC, OCD patients showed decreased P3 of P300 amplitude ( OCD group 3.5 + 1.6μv vs. NC group 5.9 +2.1 μv, P <0.01 ),delayed V latency (6.4 +0. 4ms vs. 5.5 +0.3ms, P <0.01 ) and increased V amplitude( 0.35 ±0.1μv vs. 0.16 ±0.09μv, P <0.05)of ABR and delayed P2 of VEP latency (199 ±39ms vs. 183 +28ms, P <0. 05). The followup measures of evoked potentials suggested that decreased P3 of P300 amplitude and delayed P2 of VEP latency might be state markers of OCD , while decreased V amplitude and delayed V of ABR latency might be trait markers of OCD. Conclusion The changes of P300 and VEP are related to clinical status of OCD patients, while the association between ABR and OCD symptoms need to be further investigated.

  10. Feasibility and performance evaluation of generating and recording visual evoked potentials using ambulatory Bluetooth based system. (United States)

    Ellingson, Roger M; Oken, Barry


    Report contains the design overview and key performance measurements demonstrating the feasibility of generating and recording ambulatory visual stimulus evoked potentials using the previously reported custom Complementary and Alternative Medicine physiologic data collection and monitoring system, CAMAS. The methods used to generate visual stimuli on a PDA device and the design of an optical coupling device to convert the display to an electrical waveform which is recorded by the CAMAS base unit are presented. The optical sensor signal, synchronized to the visual stimulus emulates the brain's synchronized EEG signal input to CAMAS normally reviewed for the evoked potential response. Most importantly, the PDA also sends a marker message over the wireless Bluetooth connection to the CAMAS base unit synchronized to the visual stimulus which is the critical averaging reference component to obtain VEP results. Results show the variance in the latency of the wireless marker messaging link is consistent enough to support the generation and recording of visual evoked potentials. The averaged sensor waveforms at multiple CPU speeds are presented and demonstrate suitability of the Bluetooth interface for portable ambulatory visual evoked potential implementation on our CAMAS platform.

  11. Music evokes vicarious emotions in listeners. (United States)

    Kawakami, Ai; Furukawa, Kiyoshi; Okanoya, Kazuo


    Why do we listen to sad music? We seek to answer this question using a psychological approach. It is possible to distinguish perceived emotions from those that are experienced. Therefore, we hypothesized that, although sad music is perceived as sad, listeners actually feel (experience) pleasant emotions concurrent with sadness. This hypothesis was supported, which led us to question whether sadness in the context of art is truly an unpleasant emotion. While experiencing sadness may be unpleasant, it may also be somewhat pleasant when experienced in the context of art, for example, when listening to sad music. We consider musically evoked emotion vicarious, as we are not threatened when we experience it, in the way that we can be during the course of experiencing emotion in daily life. When we listen to sad music, we experience vicarious sadness. In this review, we propose two sides to sadness by suggesting vicarious emotion.

  12. Resting Heart Rate and Auditory Evoked Potential

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    Simone Fiuza Regaçone


    Full Text Available The objective of this study was to evaluate the association between rest heart rate (HR and the components of the auditory evoked-related potentials (ERPs at rest in women. We investigated 21 healthy female university students between 18 and 24 years old. We performed complete audiological evaluation and measurement of heart rate for 10 minutes at rest (heart rate monitor Polar RS800CX and performed ERPs analysis (discrepancy in frequency and duration. There was a moderate negative correlation of the N1 and P3a with rest HR and a strong positive correlation of the P2 and N2 components with rest HR. Larger components of the ERP are associated with higher rest HR.

  13. Visual evoked potentials in rubber factory workers. (United States)

    Tandon, O P; Kumar, V


    Pattern reversal visual evoked potentials (pVEP) were studied in 39 male rubber factory workers in the age range of 18-55 years and 20 control subjects (aged 18-46 years) not exposed to the rubber factory environment. Results revealed that 20 (51%) rubber factory workers had abnormal latencies of wave P1 (dominant component of pVEP) as per accepted criteria of 99% tolerance limit set for the control group (i.e. any value above mean +3 SD of control was considered abnormal). The section-wise per cent distribution of abnormalities was vulcanization (83%), tubing (75%), calendering (60%), loading (38%) and mixing (14%). This study provides electrophysiological evidence that rubber factory environments affect the conduction processes in optical pathways from their origin in the retina to striate cortex. However, this study has its limitations in not identifying the specific chemical(s) causing these changes in VEP.

  14. Acute-Phase Inflammatory Response in Idiopathic Sudden Deafness: Pathogenic Implications


    López-González, Miguel A.; Antonio Abrante; Carmen López-Lorente; Antonio Gómez; Emilio Domínguez; Francisco Esteban


    The acute-phase inflammatory response in the peripheral bloodstream can be an expression of transient cerebral ischaemia in idiopathic sudden deafness. For this, a neurological and otorhinolaryngological examination of each patient, performing tests on audiometry, and tympanometry, haemogram, and cranial magnetic resonance were performed. The acute-phase inflammatory response manifests as an increased neutrophil/lymphocyte ratio that is detected 48–72 hours after the appearance of sudden deaf...

  15. Development of electrically evoked auditory brainstem response modules of REZ-Ⅰ domestic cochlear implant device%REZ-Ⅰ型国产人工耳蜗电诱发听性脑干反应模块的初步研究

    Institute of Scientific and Technical Information of China (English)

    丁秀勇; 张汝祥; 许长建; 樊伟; 张道行


    Objective To develop electrically evoked auditory brainstem response(EABR) modules of REZ-Ⅰ domestic cochlear implant device,and testify the reliability and validity of the modules.Methods Postoperative EABR were recorded in guinea pigs by using the self-designed EABR module.Results EABR waves were recorded in all 15 ears of 9 guinea pigs with normal hearing.The threshold was (159.00 ±50.21) current level (CL) and e Ⅲ wave latency was (2.36 ± 0.46)ms of 100 μs pulse width stimulation; for 150 μs pulse width stimulation,the threshold was (131.44 ± 49.25)CL and e Ⅲ wave latency was (2.59 ± 0.46) ms ; for 200 μs pulse width stimulation,the threshold was (119.63 ± 52.56) CL and e Ⅲ wave latency was (2.62 ± 0.44) ms.Conclusion According the preliminary results of the study,the reliability and stability of the EABR modules of domestic cochlear implant device can meet the demands of EABR recording.%目的 建立REZ-Ⅰ型国产人工耳蜗电诱发听性脑干反应(electrically evoked auditory brainstem response,EABR)模块,并测试其稳定性及可靠性.方法 使用自行设计构建的REZ-Ⅰ型国产人工耳蜗EABR测试模块记录听力正常豚鼠人工耳蜗植入后的EABR,并探索相关技术参数.结果 9只豚鼠(15耳)EABR波形引出率为100%.100μs刺激脉宽的阈值平均(均数±标准差,下同)为(159.00±50.21)电流级(current level,CL),波Ⅲ潜伏期为(2.36 ±0.46) ms;150μs刺激脉宽的阈值为(131.44 ±49.25)CL,波Ⅲ潜伏期为(2.59±0.46)ms;200 μs刺激脉宽的阈值为(119.63 ±52.56)CL,波Ⅲ潜伏期为(2.62±0.44) ms.结论 REZ-Ⅰ型人工耳蜗EABR模块动物实验的引出率达到100%,其稳定性和可靠性能够满足EABR的测试要求.

  16. 听力筛查转诊婴幼儿不同滤波条件短纯音诱发听性脑干反应的比较%Comparison of tone burst evoked auditory brainstem responses with different filter settings for referral infants after hearing screening

    Institute of Scientific and Technical Information of China (English)

    刁文雯; 倪道凤; 李奉荣; 商莹莹


    Objective Auditory brainstem responses (ABR) evoked by tone burst is an important method of hearing assessment in referral infants after hearing screening. The present study was to compare the thresholds of tone burst ABR with filter settings of 30 - 1500 Hz and 30 - 3000 Hz at each frequency,figure out the characteristics of ABR thresholds with the two filter settings and the effect of the waveform judgement, so as to select a more optimal frequency specific ABR test parameter. Methods Thresholds with filter settings of 30 - 1500 Hz and 30 -3000 Hz in children aged 2 -33 months were recorded by click,tone burst ABR. A total of 18 patients ( 8 male / 10 female), 22 ears were included. Results The thresholds of tone burst ABR with filter settings of 30 - 3000 Hz were higher than that with filter settings of 30 - 1500 Hz. Significant difference was detected for that at 0. 5 kHz and 2.0 kHz ( t values were 2.238 and 2. 217, P < 0. 05 ), no significant difference between the two filter settings was detected at the rest frequencies tone evoked ABR thresholds. The waveform of ABR with filter settings of 30 - 1500 Hz was smoother than that with filter settings of 30 - 3000 Hz at the same stimulus intensity. Response curve of the latter appeared jagged small interfering wave. Conclusions The filter setting of 30 - 1500 Hz may be a more optimal parameter of frequency specific ABR to improve the accuracy of frequency specificity ABR for infants' hearing assessment.%目的 短纯音诱发听性脑干反应(ABR)是听力筛查转诊婴幼儿听力评估的重要方法,本研究比较滤波分别为30~1500 Hz与30~3000 Hz时不同频率短纯音ABR阈值之间的差异,总结两种滤波条件下ABR波形特点及对阈值判断的影响,以选择更优化的频率特异性ABR测试参数.方法 应用美国IHS公司SmartEP听觉诱发电位仪记录18例(22耳)2~33月龄婴幼儿短声、滤波为30~1500 Hz与30~3000 Hz短纯音ABR各频率反应阈.结果 0.5 k

  17. Cardiovascular reflexes evoked by histamine stimulation of the stomach. (United States)

    Stebbins, C L; Theodossy, S J; Longhurst, J C


    This study examined the potential for histamine to cause cardiovascular reflexes when applied to the serosal or mucosal surface of the stomach. Thus, in chloralose-anesthetized cats, histamine was applied to the serosal surface of the stomach in concentrations ranging from 0.5 to 1,000 micrograms/ml. This resulted in graded increases in mean arterial pressure (MAP), maximal left ventricular pressure over time (dP/dt), and heart rate ranging from 9 +/- 4 to 30 +/- 3 mmHg, 450 +/- 103 to 1,710 +/- 610 mmHg/s, and 2 +/- 1 to 13 +/- 4 beats/min, respectively. Histamine stimulation of the gastric serosa evoked a greater pressor response than that observed when the same concentration of histamine (100 micrograms/ml) was applied to the gastric mucosa (43 +/- 7 vs. 13 +/- 3 mmHg, respectively). In six cats, celiac ganglionectomy abolished the previously observed cardiovascular response to histamine stimulation of the serosal surface of the stomach. When the gastric serosa was treated with the H1-receptor antagonist diphenhydramine (1 mg/ml) (n = 5), the cardiovascular response to histamine was abolished. In five other cats, administration of the H2-antagonist ranitidine (1 mg/ml) had no effect on the histamine-induced responses. When indomethacin (2-5 mg/ml), was applied to the serosal surface of the stomach (n = 6), histamine-induced increases in MAP and dP/dt were attenuated. However, application of PGE2 (1 microgram/ml) restored these two responses. These results suggest that histamine stimulates H1-receptors in the gastric wall to cause reflex cardiovascular responses that are dependent, in part, on the local production of prostaglandins.

  18. Temporal Tuning Effects in the Visually Evoked Response, (United States)


    Cleland, Dubin and Levick, 1971) to the occipital cortex (Ikeda and Wright, 1974). These two channels are named for the type of retinal ganglion cells...external address was electroically stepped 256 times for each pattern revrsal, thus ensuring an exact integer number of stimulus presentations (4) within... electro - physiologically. Arch Ophthalmol. 84: 272-278. Milner, B.A., Regan, D., and Heron, J.R. (1972) Theorectical models of the generation of study

  19. Purinoceptors Evoke Different Electrophysiological Responses in Pancreatic Ducts

    DEFF Research Database (Denmark)

    Hede, S E; Amstrup, Jan; Christoffersen, Bettina C;


    , and a decrease in the whole-cell conductance. The membrane effects were due to closure of K(+) channels, as confirmed by dependence on extracellular K(+). UTP/ATP effects could be associated with P2Y(2) purinoceptors, and RT-PCR revealed mRNAs for P2Y(2) and P2Y(4) receptors. On the other hand, 2', 3'-O-4...

  20. Calcium spikes and calcium plateaux evoked by differential polarization in dendrites of turtle motoneurones in vitro

    DEFF Research Database (Denmark)

    Hounsgaard, J; Kiehn, O


    -evoked regenerative responses was relatively insensitive to somatic bias current. 6. TTX-resistant Ca(2+)-mediated plateau potentials promoted by apamin were evoked by differential polarization in both the soma-depolarizing and soma-hyperpolarizing direction. 7. It is concluded that Ca2+ channels responsible for Ca2......The ability of dendrites in turtle motoneurones to support calcium spikes and calcium plateaux was investigated using differential polarization by applied electric fields. 2. Electric fields were generated by passing current through transverse slices of the turtle spinal cord between two plate......-hyperpolarizing and soma-depolarizing direction of the field. The different components of Ca2+ spikes were discrete and additive. High amplitude components had higher threshold and faster time course and were followed by larger after-hyperpolarizations, than low amplitude components. The frequency of field...

  1. Chirp-modulated visual evoked potential as a generalization of steady state visual evoked potential (United States)

    Tu, Tao; Xin, Yi; Gao, Xiaorong; Gao, Shangkai


    Visual evoked potentials (VEPs) are of great concern in cognitive and clinical neuroscience as well as in the recent research field of brain-computer interfaces (BCIs). In this study, a chirp-modulated stimulation was employed to serve as a novel type of visual stimulus. Based on our empirical study, the chirp stimuli visual evoked potential (Chirp-VEP) preserved frequency features of the chirp stimulus analogous to the steady state evoked potential (SSVEP), and therefore it can be regarded as a generalization of SSVEP. Specifically, we first investigated the characteristics of the Chirp-VEP in the time-frequency domain and the fractional domain via fractional Fourier transform. We also proposed a group delay technique to derive the apparent latency from Chirp-VEP. Results on EEG data showed that our approach outperformed the traditional SSVEP-based method in efficiency and ease of apparent latency estimation. For the recruited six subjects, the average apparent latencies ranged from 100 to 130 ms. Finally, we implemented a BCI system with six targets to validate the feasibility of Chirp-VEP as a potential candidate in the field of BCIs.

  2. Auditory evoked potentials in peripheral vestibular disorder individuals

    Directory of Open Access Journals (Sweden)

    Matas, Carla Gentile


    Full Text Available Introduction: The auditory and vestibular systems are located in the same peripheral receptor, however they enter the CNS and go through different ways, thus creating a number of connections and reaching a wide area of the encephalon. Despite going through different ways, some changes can impair both systems. Such tests as Auditory Evoked Potentials can help find a diagnosis when vestibular alterations are seen. Objective: describe the Auditory Evoked Potential results in individuals complaining about dizziness or vertigo with Peripheral Vestibular Disorders and in normal individuals having the same complaint. Methods: Short, middle and long latency Auditory Evoked Potentials were performed as a transversal prospective study. Conclusion: individuals complaining about dizziness or vertigo can show some changes in BAEP (Brainstem Auditory Evoked Potential, MLAEP (Medium Latency Auditory Evoked Potential and P300.

  3. Multimodal evoked potential abnormalities in patients with Wilson's disease

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    Ilić Tihomir V.


    Full Text Available The aim of this study was to investigate the involvement of the following functional systems: somatosensory evoked potentials (SSEP, visual evoked potentials (VEP, and event related potentials (ERP, in twenty patients with Wilson's disease (WD. VEP and SSEP abnormalities were discovered in S patients respectively (40%, whereas ERP were either absent or, in the case of 10 patients (50%, had significantly prolonged P-300 latencies. Taken together, at least one evoked potential abnormality was discovered in 17 patients (85%]. Only in 3 patients (15%, involving either the isolated hepatic type of disease or short illness duration of the neurological type, were normal evoked potential findings observed. Our findings suggest the usefulness of multimodal evoked potential abnormalities in the evaluation of subclinical manifestations in patients with WD.

  4. Nocifensive behavior-related laser heat-evoked component in the rostral agranular insular cortex revealed using morphine analgesia. (United States)

    Wu, Wen-Yi; Liu, Chan-Ying; Tsai, Meng-Li; Yen, Chen-Tung


    The rostral agranular insular cortex (RAIC), an opioid-responsive site, is essential for modulating nociception in rats. Our previous studies have shown that morphine suppressed long latency laser heat-evoked nociceptive responses in the primary somatosensory cortex (SmI). By contrast, morphine significantly attenuated both short and long latency responses in the anterior cingulate cortex (ACC). The present study assessed the effect of morphine on laser heat-evoked responses in the RAIC. Laser heat irradiation applied to the rat forepaws at graded levels was used as a specific noxious stimulus. In the RAIC, the first part of the long latency component (140-250ms) of the laser heat-evoked response was enhanced by intraperitoneal morphine (5mg/kg). When the laser heat-evoked cortical responses were examined for trials showing strong nocifensive movement (paw licking), moderate nocifensive movement (paw lifting), and no nocifensive movement, a 140-250ms period enhancement was observed in the RAIC only for the paw lifting movement. This enhancement was absent in the SmI. Thus, our data suggest that the RAIC has a pain-related behavior-dependent neuronal component. Furthermore, the RAIC, ACC, and SmI are differentially modulated by morphine analgesia.

  5. Triceps surae stretch reflex modulation after a mechanically evoked ankle dorsiflexion during the swing phase of human running. (United States)

    Scohier, Mikael; De Jaeger, Dominique; Schepens, Benedicte


    The purpose of this study was to mechanically evoke a triceps surae stretch reflex during the swing phase of running, to study its within-the-step phase dependency. Seven participants ran on a treadmill at 2.8 m·s-1 wearing an exoskeleton capable of evoking a sudden ankle dorsiflexion. We measured the electromyographic activity of the soleus, medial and lateral gastrocnemii just after the perturbation to evaluate the triceps surae stretch reflex. Similar perturbations were also delivered at rest. Our results showed that the stretch reflex was suppressed during the swing phase of running, except in late swing where a late reflex response was observed. At rest, all triceps surae muscles showed an early reflex response to stretch. Our findings suggest that the triceps surae short/medium-latency stretch reflex cannot be evoked during swing phase and thus cannot contribute to the control of the locomotor pattern after aperturbation during this phase.

  6. Potenciais evocados auditivos de tronco encefálico por frequência específica e de estado estável na audiologia pediátrica: estudo de caso Frequency-specific and steady-state evoked auditory brainstem responses in pediatric audiology: case study

    Directory of Open Access Journals (Sweden)

    Gabriela Ribeiro Ivo Rodrigues


    Full Text Available Preconiza-se o diagnóstico até os três meses de idade em crianças com deficiência auditiva congênita. Após a etapa inicial de confirmação do diagnóstico, é necessário que se obtenha limiares precisos nas diferentes frequências, para que seja possível uma adequada seleção, indicação e regulagem de aparelhos de amplificação sonora. Nesse contexto, inserem-se os Potenciais Evocados Auditivos de Tronco Encefálico por Frequência Específica (PEATE-FE e, mais recentemente, os Potenciais Evocados Auditivos de Estado Estável (PEAEE. O objetivo deste estudo de caso foi apresentar os achados das duas técnicas para estimar os limiares auditivos em uma criança de três meses de idade, com perda auditiva neurossensorial bilateral, diagnosticada utilizando-se como primeiro método de avaliação os Potenciais Evocados Auditivos de Tronco Encefálico com estímulo clique, tanto por via aérea como por via óssea. As duas técnicas mostraram-se eficientes para estimar os limiares auditivos, com uma vantagem dos PEAEE com relação ao tempo de duração de exame.It is recommended that congenital hearing loss is identified as early as three months old. After the initial step of confirming the diagnosis, it is necessary to obtain accurate hearing thresholds, allowing an adequate selection, indication and regulation of hearing aids for these children. It is inserted, in this context, the Frequency-Specific Auditory Brainstem Responses (FSABR and, more recently, the Auditory Steady-State Responses (ASSR. The aim of the present study was to describe the findings of the use of both techniques to estimate the auditory thresholds of a three-month-old infant with bilateral sensorineural hearing loss diagnosed using, as primary evaluation method, the click-evoked Auditory Brainstem Responses, with both air and bone stimuli conduction. Both techniques provided reliable findings for estimating auditory thresholds. The ASSR had an advantage regarding

  7. Bogus visual feedback alters movement-evoked pain onset in people with neck pain



    Pain is a protective perceptual response shaped by contextual, psychological and sensory inputs, particularly those that suggest danger to the body. Sensory cues suggesting that a vulnerable body part is moving towards a painful position, may credibly signal danger and thereby modulate pain . In this double-blind repeated-measures experiment, we used virtual reality to investigate whether manipulating visual-proprioceptive cues can alter movement-evoked pain, in 24 people with neck pain. W...

  8. Catecholamine release evoked by lithium from the perfused adrenal gland of the cat.


    de Abajo, F. J.; Castro, M. A.; Garijo, B; Sánchez-García, P.


    The effect of Li on catecholamine release by cat isolated retrogradely perfused adrenal gland was investigated. Replacement of Na (119 mM) by Li in the Krebs solution evoked a progressive increase in the spontaneous release of catecholamines that reached a maximum within 45 min and was Ca-dependent. This response was specific for Li, since sucrose or choline used as osmotic substitutes for Na, failed to increase the spontaneous release of catecholamines by the adrenal gland. In glands perfuse...

  9. A study on early detection of changes in visual pathway due to Diabetes mellitus by visual evoked potential

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar, Sundararajan D, Rajvin Samuel Ponraj, M Srinivasan


    Full Text Available Electrical potentials have been recorded by surface Evoked Potentials namely the Somatosensory Evoked Potential, Auditory Brainstem Response and Visual Evoked Potential [VEP]. Visual conduction disturbance can be evaluated by these instruments. A mass response of cortical and possibly subcortical may be represented, visual areas to visual stimuli. Diabetic patients without a past history of cerebrovascular accidents diagnosed with Non- Proliferative Diabetic retinopathy[DR] with a best corrected visual acuity at least 6/9.This study was done to assess whether a delay in VEP latency observed in diagnosed type II DM patients could be ascribed to dysfunction of the retinal or post retinal structures or by both. It is to find out whether the VEP latencies are altered in diabetes or not, if altered and to correlate duration of the diabetes mellitus with visual evoked potential changes. Visual evoked potentials are useful as a non invasive investigatory method in establishing central nervous system neuropathy developing in diabetes. This study clearly shows that changes in VEP may be detected in diabetics before the onset of retinopathy. Future studies should be focused on evaluation of the time that elapses between the appearance of the first detectable pathologic electrophysiologic changes and the first ophthalmoscopically detectable retinal changes in patients with Diabetes Mellitus [DM].

  10. Hearing threshold estimation by auditory steady-state responses with narrow-band chirps and adaptive stimulus patterns: implementation in clinical routine. (United States)

    Seidel, David Ulrich; Flemming, Tobias Angelo; Park, Jonas Jae-Hyun; Remmert, Stephan


    Objective hearing threshold estimation by auditory steady-state responses (ASSR) can be accelerated by the use of narrow-band chirps and adaptive stimulus patterns. This modification has been examined in only a few clinical studies. In this study, clinical data is validated and extended, and the applicability of the method in audiological diagnostics routine is examined. In 60 patients (normal hearing and hearing impaired), ASSR and pure tone audiometry (PTA) thresholds were compared. ASSR were evoked by binaural multi-frequent narrow-band chirps with adaptive stimulus patterns. The precision and required testing time for hearing threshold estimation were determined. The average differences between ASSR and PTA thresholds were 18, 12, 17 and 19 dB for normal hearing (PTA ≤ 20 dB) and 5, 9, 9 and 11 dB for hearing impaired (PTA > 20 dB) at the frequencies of 500, 1,000, 2,000 and 4,000 Hz, respectively, and the differences were significant in all frequencies with the exception of 1 kHz. Correlation coefficients between ASSR and PTA thresholds were 0.36, 0.47, 0.54 and 0.51 for normal hearing and 0.73, 0.74, 0.72 and 0.71 for hearing impaired at 500, 1,000, 2,000 and 4,000 Hz, respectively. Mean ASSR testing time was 33 ± 8 min. In conclusion, auditory steady-state responses with narrow-band-chirps and adaptive stimulus patterns is an efficient method for objective frequency-specific hearing threshold estimation. Precision of threshold estimation is most limited for slighter hearing loss at 500 Hz. The required testing time is acceptable for the application in everyday clinical routine.

  11. Glucagon-like peptide-1 modulates neurally evoked mucosal chloride secretion in guinea pig small intestine in vitro. (United States)

    Baldassano, Sara; Wang, Guo-Du; Mulè, Flavia; Wood, Jackie D


    Glucagon-like peptide-1 (GLP-1) acts at the G protein-coupled receptor, GLP-1R, to stimulate secretion of insulin and to inhibit secretion of glucagon and gastric acid. Involvement in mucosal secretory physiology has received negligible attention. We aimed to study involvement of GLP-1 in mucosal chloride secretion in the small intestine. Ussing chamber methods, in concert with transmural electrical field stimulation (EFS), were used to study actions on neurogenic chloride secretion. ELISA was used to study GLP-1R effects on neural release of acetylcholine (ACh). Intramural localization of GLP-1R was assessed with immunohistochemistry. Application of GLP-1 to serosal or mucosal sides of flat-sheet preparations in Ussing chambers did not change baseline short-circuit current (I(sc)), which served as a marker for chloride secretion. Transmural EFS evoked neurally mediated biphasic increases in I(sc) that had an initial spike-like rising phase followed by a sustained plateau-like phase. Blockade of the EFS-evoked responses by tetrodotoxin indicated that the responses were neurally mediated. Application of GLP-1 reduced the EFS-evoked biphasic responses in a concentration-dependent manner. The GLP-1 receptor antagonist exendin-(9-39) suppressed this action of GLP-1. The GLP-1 inhibitory action on EFS-evoked responses persisted in the presence of nicotinic or vasoactive intestinal peptide receptor antagonists but not in the presence of a muscarinic receptor antagonist. GLP-1 significantly reduced EFS-evoked ACh release. In the submucosal plexus, GLP-1R immunoreactivity (IR) was expressed by choline acetyltransferase-IR neurons, neuropeptide Y-IR neurons, somatostatin-IR neurons, and vasoactive intestinal peptide-IR neurons. Our results suggest that GLP-1R is expressed in guinea pig submucosal neurons and that its activation leads to a decrease in neurally evoked chloride secretion by suppressing release of ACh at neuroepithelial junctions in the enteric neural networks

  12. External QX-314 inhibits evoked cranial primary afferent synaptic transmission independent of TRPV1. (United States)

    Hofmann, Mackenzie E; Largent-Milnes, Tally M; Fawley, Jessica A; Andresen, Michael C


    The cell-impermeant lidocaine derivative QX-314 blocks sodium channels via intracellular mechanisms. In somatosensory nociceptive neurons, open transient receptor potential vanilloid type 1 (TRPV1) receptors provide a transmembrane passageway for QX-314 to produce long-lasting analgesia. Many cranial primary afferents express TRPV1 at synapses on neurons in the nucleus of the solitary tract and caudal trigeminal nucleus (Vc). Here, we investigated whether QX-314 interrupts neurotransmission from primary afferents in rat brain-stem slices. Shocks to the solitary tract (ST) activated highly synchronous evoked excitatory postsynaptic currents (ST-EPSCs). Application of 300 μM QX-314 increased the ST-EPSC latency from TRPV1+ ST afferents, but, surprisingly, it had similar actions at TRPV1- ST afferents. Continued exposure to QX-314 blocked evoked ST-EPSCs at both afferent types. Neither the time to onset of latency changes nor the time to ST-EPSC failure differed between responses for TRPV1+ and TRPV1- inputs. Likewise, the TRPV1 antagonist capsazepine failed to prevent the actions of QX-314. Whereas QX-314 blocked ST-evoked release, the frequency and amplitude of spontaneous EPSCs remained unaltered. In neurons exposed to QX-314, intracellular current injection evoked action potentials suggesting a presynaptic site of action. QX-314 acted similarly at Vc neurons to increase latency and block EPSCs evoked from trigeminal tract afferents. Our results demonstrate that QX-314 blocked nerve conduction in cranial primary afferents without interrupting the glutamate release mechanism or generation of postsynaptic action potentials. The TRPV1 independence suggests that QX-314 either acted extracellularly or more likely entered these axons through an undetermined pathway common to all cranial primary afferents.

  13. A Study of Relationship between the Acoustic Sensitivity of Vestibular System and the Ability to Trigger Sound-Evoked Muscle Reflex of the Middle Ear in Adults with Normal Hearing

    Directory of Open Access Journals (Sweden)

    S.F. Emami


    Full Text Available Introduction & Objective: The vestibular system is sound sensitive and the sensitivity is related to the saccule. The vestibular afferents are projected to the middle ear muscles (such as the stapedius. The goal of this research was studying the relationship between the vestibular hearing and the sound-evoked muscle reflex of the middle ear to 500 HZ. Materials & Methods: This study was a cross sectional-comparison done in audiology department of Sheikholreis C‍‍linic (Hamadan, Iran. The study groups consisted of thirty healthy people and thirty patients with benign paroxysmal positional vertigo. Inclusion criteria of the present study were to have normal hearing on pure tone audiometry, acoustic reflex, and speech discrimination scores. Based on ipsilateral acoustic reflex test at 500HZ, they were divided to normal and abnormal groups. Then they were evaluated by cervical vestibular evoked myogenic potentials (cVEMPs and finally classified in three groups (N Normal ear , (CVUA Contra lateral vertiginous ear with unaffected saccular sensitivity to sound,(IVA Ipsilateral vertiginous ear with affected saccular sensitivity to sound. Results: Thirty affected ears (IVA with decreased vestibular excitability as detected by ab-normal cVEMPs, revealed abnormal findings of acoustic reflex at 500HZ. Whereas, both un-affected (CVUA and normal ears (N had normal results. Multiple comparisons of mean values of cVEMPs (p13,n23 and acoustic reflex at500HZ among the three groups were sig-nificant. The correlation between acoustic reflex at 500HZ and p13 latencies was significant. The n23 latencies showed significant correlation with acoustic reflex at 500HZ. Conclusion: The vestibular sensitivity to sound retains the ability to trigger sound-evoked re-flex of the middle ear at 500 HZ. (Sci J Hamadan Univ Med Sci 2014; 21 (2:99-104

  14. Grating-evoked cortical potentials and perceived contrast (A) (United States)

    Strasburger, Hans; Scheidler, Wolfgang; Rentschler, Ingo

    Unlike subjective perception of contrast, steady-state evoked cortical potentials (VEP's) elicited with counterphased gratings may vary abruptly with changes in spatial frequency.(1) To avoid possible artifacts we developed a digital fast-sweep technique for investigating this discrepancy. In most of our 13 subjects, at high stimulus contrasts the dependency of VEP amplitude on spatial frequency had two pronounced peaks separated by a sharp notch at around 3 cycles per degree. With decreasing contrast these variations leveled out, and a unimodal response function was obtained at low contrast. A linear relationship between log contrast and VEP amplitude(2) was found for any given spatial frequency only in the low-contrast range. With increasing contrast the VEP amplitude saturated at a rate that depended clearly on spatial frequency, with a nonmonotonous dependency occurring at intermediate spatial frequencies. The latter phenomenon of oversaturation apparently gave rise to the above-mentioned bimodal response characteristic. Results of a careful analysis of VEP phase lags are added. (1) C. W. Tyler et al., Brain Res. 33, 535 (1978). (2) F. W. Campbell and L. Maffei, J. Physiol. 207, 635 (1970).

  15. Changes of Transient Visual Evoked Potentials in Dyslexic Children

    Directory of Open Access Journals (Sweden)

    Ka Yan Leung


    Full Text Available Objectives: To investigate the characteristics of Visual Evoked Potentials (VEP in dyslexics. Methods: Fourteen children, 7 dyslexics and 7 control, aged 7 to 8 years were recruited. All dyslexic subjects were diagnosed by clinical psychologist. All subjects are from mainstream primary schools in Hong Kong, using Chinese and Cantonese as their primary written and spoken language, having normal visual acuity and IQ. Children with reported emotional or behavioral problems or binocular vision problem were excluded. All the subjects participated in pattern-reversal VEP measurements binocularly with 1000msec recording time. Four conditions of stimulations (checkersize: 180 min of arc were applied. (15-Hz at 15% contrast (25-Hz at 1% contrast (315-Hz at 15% contrast (415-Hz at 1% contrast Results: At 15% contrast stimulus, dyslexic subjects showed smaller amplitudes in both frequencies compared with the control group, especially in higher frequency. At 1% contrast stimulus, dyslexic subjects also showed smaller amplitudes in both frequencies and obvious reduction was observed at the later part of the recording period. No observable difference was showed in the latency of both contrast conditions. Conclusion: The attenuated VEP responses in higher frequency at low contrast condition in dyslexic group showed the changes of the transient visual response and this implies an abnormality in magnocellular pathway in dyslexia.

  16. Vestibular evoked myogenic potentials in patients with ankylosing spondylitis. (United States)

    Özgür, Abdulkadir; Serdaroğlu Beyazal, Münevver; Terzi, Suat; Coşkun, Zerrin Özergin; Dursun, Engin


    Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease with unknown etiology. Although sacroiliac joint involvement is the classic sign along with the formed immune mediators, it may result in immune-mediated inner ear disease and may cause damage to the audiovestibular system. Vestibular evoked myogenic potentials (VEMP) is a clinical reflex test used in the diagnosis of vestibular diseases and is performed by recording and evaluating the muscle potentials resulting from the stimulation of the vestibular system with different stimuli. The aim of this study is to evaluate the cervical VEMP test results in AS patients without vestibular symptoms. Thirty-three patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. VEMP wave latency, P13-N23 wave amplitude, and VEMP asymmetry ratio (VAR) values were compared between the groups. The relationship between clinical and laboratory findings of the AS patients and VEMP data were also investigated. Compared with healthy people, this study shows the response rate of patients with ankylosing spondylitis was reduced in the VEMP test, and P13-N23 wave amplitude showed a decrease in AS patients who had VEMP response (p ankylosing spondylitis. The data obtained from this study suggest that AS may lead to decreased sensitivity of the vestibular system.

  17. Stimulation of NTS A1 adenosine receptors evokes counteracting effects on hindlimb vasculature. (United States)

    McClure, Joseph M; O'Leary, Donal S; Scislo, Tadeusz J


    Our previous studies concluded that stimulation of the nucleus of the solitary tract (NTS) A2a receptors evokes preferential hindlimb vasodilation mainly via inducing increases in preganglionic sympathetic nerve activity (pre-ASNA) directed to the adrenal medulla. This increase in pre-ASNA causes the release of epinephrine and subsequent activation of beta-adrenergic receptors that are preferentially located in the skeletal muscle vasculature. Selective activation of NTS A1 adenosine receptors evokes variable, mostly pressor effects and increases pre-ASNA, as well as lumbar sympathetic activity, which is directed to the hindlimb. These counteracting factors may have opposite effects on the hindlimb vasculature resulting in mixed vascular responses. Therefore, in chloralose-urethane-anesthetized rats, we evaluated the contribution of vasodilator versus vasoconstrictor effects of stimulation of NTS A1 receptors on the hindlimb vasculature. We compared the changes in iliac vascular conductance evoked by microinejctions into the NTS of the selective A1 receptor agonist N6-cyclopentyladenosine (330 pmol in 50 nl volume) in intact animals with the responses evoked after beta-adrenergic blockade, bilateral adrenalectomy, bilateral lumbar sympathectomy, and combined adrenalectomy + lumbar sympathectomy. In intact animals, stimulation of NTS A1 receptors evoked variable effects: increases and decreases in mean arterial pressure and iliac conductance with prevailing pressor and vasoconstrictor effects. Peripheral beta-adrenergic receptor blockade and bilateral adrenalectomy eliminated the depressor component of the responses, markedly potentiated iliac vasoconstriction, and tended to increase the pressor responses. Lumbar sympathectomy tended to decrease the pressor and vasoconstrictor responses. After bilateral adrenalectomy plus lumbar sympathectomy, a marked vasoconstriction in iliac vascular bed still persisted, suggesting that the vasoconstrictor component of the

  18. Cortical evoked potentials recorded from the guinea pig without averaging. (United States)

    Walloch, R A


    Potentials evoked by tonal pulses and recorded with a monopolar electrode on the pial surface over the auditory cortex of the guinea pig are presented. These potentials are compared with average potentials recorded in previous studies with an electrode on the dura. The potentials recorded by these two techniques have similar waveforms, peak latencies and thresholds. They appear to be generated within the same region of the cerebral cortex. As can be expected, the amplitude of the evoked potentials recorded from the pial surface is larger than that recorded from the dura. Consequently, averaging is not needed to extract the evoked potential once the dura is removed. The thresholds for the evoked cortical potential are similar to behavioral thresholds for the guinea pig at high frequencies; however, evoked potential thresholds are eleveate over behavioral thresholds at low frequencies. The removal of the dura and the direct recording of the evoked potential appears most appropriate for acute experiments. The recording of an evoked potential with dura electrodes empploying averaging procedures appears most appropriate for chronic studies.

  19. Electroretinography and Visual Evoked Potentials in Childhood Brain Tumor Survivors. (United States)

    Pietilä, Sari; Lenko, Hanna L; Oja, Sakari; Koivisto, Anna-Maija; Pietilä, Timo; Mäkipernaa, Anne


    This population-based cross-sectional study evaluates the clinical value of electroretinography and visual evoked potentials in childhood brain tumor survivors. A flash electroretinography and a checkerboard reversal pattern visual evoked potential (or alternatively a flash visual evoked potential) were done for 51 survivors (age 3.8-28.7 years) after a mean follow-up time of 7.6 (1.5-15.1) years. Abnormal electroretinography was obtained in 1 case, bilaterally delayed abnormal visual evoked potentials in 22/51 (43%) cases. Nine of 25 patients with infratentorial tumor location, and altogether 12 out of 31 (39%) patients who did not have tumors involving the visual pathways, had abnormal visual evoked potentials. Abnormal electroretinographies are rarely observed, but abnormal visual evoked potentials are common even without evident anatomic lesions in the visual pathway. Bilateral changes suggest a general and possibly multifactorial toxic/adverse effect on the visual pathway. Electroretinography and visual evoked potential may have clinical and scientific value while evaluating long-term effects of childhood brain tumors and tumor treatment.

  20. Mechanical Stimulation by Postnasal Drip Evokes Cough. (United States)

    Iwata, Toshiyuki; Ito, Isao; Niimi, Akio; Ikegami, Koji; Marumo, Satoshi; Tanabe, Naoya; Nakaji, Hitoshi; Kanemitsu, Yoshihiro; Matsumoto, Hisako; Kamei, Junzo; Setou, Mitsutoshi; Mishima, Michiaki


    Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough.

  1. Mechanical Stimulation by Postnasal Drip Evokes Cough.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Iwata

    Full Text Available Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough.

  2. [Intraoperative monitoring of visual evoked potentials]. (United States)

    Sasaki, Tatsuya; Ichikawa, Tsuyoshi; Sakuma, Jun; Suzuki, Kyouichi; Matsumoto, Masato; Itakura, Takeshi; Kodama, Namio; Murakawa, Masahiro


    Our success rate of intraoperative monitoring of visual evoked potential (VEP) had been approximately 30% in the past. In order to improve recording rate of intraoperative VEP, we developed a new stimulating device using high power light emitting diodes. Electroretinogram was simultaneously recorded to understand whether flash stimulation reached the retina. In addition, total venous anesthesia with propofol was used to avoid the adverse effect of inhalation anesthesia. We report the results after introduction of these improvements. Intraoperative monitoring of VEP was attempted in 35 cases. We evaluated success rate of VEP recording, correlation between VEP findings and postoperative visual function, and reasons why recording was not successful. Stable and reproducible waveforms were obtained in 59 sides (84%). Two cases, whose VEP deteriorated intraoperatively, developed postoperative visual disturbance: In 11 sides (16%), stable waveforms were not obtained. There were two main causes. In 8 sides out of 11, the cause was attributed to pre-existing severe visual disturbance. In these 8 sides, VEP in the awake state was not recordable or was recordable, but with very low amplitudes under 1 microV. In the other 3 sides, the cause was attributed to movement of a stimulating device by reflecting the fronto-temporal scalp flap. In conclusion, the successful recording rate was increased to 84% from approximately 30%, after introduction of various trials. We need further improvement in recording intraoperative VEP to establish a reliable intraoperative monitoring method for VEP.


    Institute of Scientific and Technical Information of China (English)


    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatosensory evoked potentials (SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 normal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and amplitude (P38- N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amplitudes of cerebral evoked potentials by magnetic stimulation of calf muscle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2.9± 2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged (P<0.01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients.? Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  4. [Brainstem auditory evoked potentials and somatosensory evoked potentials in Chiari malformation]. (United States)

    Moncho, Dulce; Poca, María A; Minoves, Teresa; Ferré, Alejandro; Rahnama, Kimia; Sahuquillo, Juan


    Introduccion. La malformacion de Chiari (MC) incluye una serie de anomalias congenitas que tienen como comun denominador la ectopia de las amigdalas del cerebelo por debajo del foramen magno, lo que puede condicionar fenomenos compresivos del troncoencefalo, la medula espinal alta y los nervios craneales, alterando las respuestas de los potenciales evocados auditivos del tronco cerebral (PEATC) y de los potenciales evocados somatosensoriales (PESS). Sin embargo, las indicaciones de ambas exploraciones en las MC han sido motivo de estudio en un numero limitado de publicaciones, centradas en series cortas y heterogeneas de pacientes. Objetivo. Revisar los hallazgos de los PEATC y los PESS en los estudios publicados en pacientes con MC tipo 1 (MC-1) o tipo 2 (MC-2), y su indicacion en el diagnostico, tratamiento y seguimiento, especialmente en la MC-1. Desarrollo. Es un estudio de revision realizado mediante analisis de los estudios publicados en Medline desde 1966, localizados mediante PubMed, utilizando combinaciones de las palabras clave 'Chiari malformation', 'Arnold-Chiari malformation', 'Chiari type 1 malformation', 'Arnold-Chiari type 1 malformation', 'evoked potentials', 'brainstem auditory evoked potentials' y 'somatosensory evoked potentials', asi como informacion de pacientes con MC-1 valorados en los servicios de neurocirugia y neurofisiologia clinica del Hospital Universitari Vall d'Hebron. Conclusiones. Los hallazgos mas comunes de los PESS son la reduccion en la amplitud cortical para el nervio tibial posterior, la reduccion o ausencia del potencial cervical del nervio mediano y el aumento del intervalo N13-N20. En el caso de los PEATC, los hallazgos mas frecuentes descritos son el aumento del intervalo I-V y la alteracion periferica o coclear.

  5. Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion (United States)

    Lim, Hyo-Jeong; Lee, Hyun-Young


    The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 (3~30 µM), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 (10 µM) also time-dependently inhibited the CA secretion evoked by DMPP (100 µM, a selective neuronal nicotinic receptor agonist) and high K+ (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 (50 µg/mL), the secretory responses of CA evoked by veratridine (a selective Na+ channel activator (50 µM), Bay-K-8644 (an L-type dihydropyridine Ca2+ channel activator, 10 µM), and cyclopiazonic acid (a cytoplasmic Ca2+-ATPase inhibitor, 10 µM) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 (10 µM) and L-NAME (an inhibitor of NO synthase, 30 µM), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 (10 µM) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of Ca2+ and Na+ into the adrenomedullary chromaffin cells and also by suppressing the release of Ca2+ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade. PMID:25352764


    Carbaryl is a widely used N-methyl carbamate pesticide that acts by inhibiting cholinesterases (ChE), which may lead to cholinergic toxicity. Flash evoked potentials (FEPs) are a neurophysiological response often used to detect central nervous system (CNS) changes following expos...

  7. Altered Automatic Face Processing in Individuals with High-Functioning Autism Spectrum Disorders: Evidence from Visual Evoked Potentials (United States)

    Fujita, Takako; Kamio, Yoko; Yamasaki, Takao; Yasumoto, Sawa; Hirose, Shinichi; Tobimatsu, Shozo


    Individuals with autism spectrum disorders (ASDs) have different automatic responses to faces than typically developing (TD) individuals. We recorded visual evoked potentials (VEPs) in 10 individuals with high-functioning ASD (HFASD) and 10 TD individuals. Visual stimuli consisted of upright and inverted faces (fearful and neutral) and objects…

  8. Influence of the power-spectrum of the pre-stimulus EEG on the consecutive Auditory Evoked Potential in rats.

    NARCIS (Netherlands)

    Jongsma, M.L.A.; Quian Quiroga, R.; Rijn, C.M. van; Schaijk, W.J. van; Dirksen, R.; Coenen, A.M.L.


    Evoked Potentials (EPs) are responses that appear in the EEG due to external stimulation. Findings indicate that changes in EPs can be related to changes in frequencies of the pre-stimulus EEG. Auditory EPs of rats (n=8) were measured in reaction to tone-pip stimuli (90 dB, 10.2 kHz, ISI 2s, n=1500)

  9. Evoked potentials and head injury. 1. Rating of evoked potential abnormality. (United States)

    Rappaport, M; Hall, K; Hopkins, H K; Belleza, T


    This paper describes a method for rating the degree of abnormality of auditory, visual and somatosensory evoked potential patterns in head injury (HI) patients. Criteria for judging degree of EP abnormality are presented that allow assessment of the extent and severity of subcortical and cortical dysfunction associated with traumatic brain damage. Interrater reliability data based upon blind ratings of normal and HI patients are presented and shown to be highly significant. Tables of normative values of peak latencies and amplitudes are given and illustrations of EP patterns of different degrees of abnormality are presented.

  10. Genetic ablation of GINIP-expressing primary sensory neurons strongly impairs Formalin-evoked pain (United States)

    Urien, Louise; Gaillard, Stéphane; Lo Re, Laure; Malapert, Pascale; Bohic, Manon; Reynders, Ana; Moqrich, Aziz


    Primary sensory neurons are heterogeneous by myriad of molecular criteria. However, the functional significance of this remarkable heterogeneity is just emerging. We precedently described the GINIP+ neurons as a new subpopulation of non peptidergic C-fibers encompassing the free nerve ending cutaneous MRGPRD+ neurons and C-LTMRs. Using our recently generated ginip mouse model, we have been able to selectively ablate the GINIP+ neurons and assess their functional role in the somatosensation. We found that ablation of GINIP+ neurons affected neither the molecular contents nor the central projections of the spared neurons. GINIP-DTR mice exhibited impaired sensation to gentle mechanical stimuli applied to their hairy skin and had normal responses to noxious mechanical stimuli applied to their glabrous skin, under acute and injury-induced conditions. Importantly, loss of GINIP+ neurons significantly altered formalin-evoked first pain and drastically suppressed the second pain response. Given that MRGPRD+ neurons have been shown to be dispensable for formalin-evoked pain, our study suggest that C-LTMRs play a critical role in the modulation of formalin-evoked pain. PMID:28240741

  11. The effectiveness of FES-evoked EMG potentials to assess muscle force and fatigue in individuals with spinal cord injury. (United States)

    Ibitoye, Morufu Olusola; Estigoni, Eduardo H; Hamzaid, Nur Azah; Wahab, Ahmad Khairi Abdul; Davis, Glen M


    The evoked electromyographic signal (eEMG) potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES)-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p SCI) population.

  12. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    Directory of Open Access Journals (Sweden)

    Roberto Vincis


    Full Text Available Functional brain-imaging techniques used in humans and animals, such as functional MRI and intrinsic optical signal (IOS imaging, are thought to largely rely on neurovascular coupling and hemodynamic responses. Here, taking advantage of the well-described micro-architecture of the mouse olfactory bulb, we dissected the nature of odor-evoked IOSs. Using in vivo pharmacology in transgenic mouse lines reporting activity in different cell types, we show that parenchymal IOSs are largely independent of neurotransmitter release and neurovascular coupling. Furthermore, our results suggest that odor-evoked parenchymal IOSs originate from changes in light scattering of olfactory sensory neuron axons, mostly due to water movement following action potential propagation. Our study sheds light on a direct correlate of neuronal activity, which may be used for large-scale functional brain imaging.

  13. Characteristics of brain stem auditory evoked potentials in children with hearing impairment due to infectious diseases. (United States)

    Ječmenica, Jovana Radovan; Opančina, Aleksandra Aleksandar Bajec


    Among objective audiologic tests, the most important were tests of brain stem auditory evoked potentials. The objective of the study was to test the configuration, degree of hearing loss, and response characteristics of auditory brain stem evoked potentials in children with hearing loss occurred due to infectious disease. A case control study design was used. The study group consisted of 54 patients referred for a hearing test because of infectious diseases caused by other agents or that occurred as congenital infection. Infectious agents have led to the emergence of various forms of sensorineural hearing loss. We have found deviations from the normal values of absolute and interwave latencies in some children in our group. We found that in the group of children who had the diseases such as purulent meningitis, or were born with rubella virus and cytomegalovirus infection, a retrocochlear damage was present in children with and without cochlear damage.

  14. Evoked potentials elicited by natural stimuli in the brain of unanesthetized crayfish. (United States)

    Hernández-Falcón, J; Serrato, J; Ramón, F


    Experiments were conducted to test some characteristics of vision by crayfish underwater and in air, and determine possible motion reactions elicited in response to naturalistic or quasi-ethological visual stimuli. Chronically implanted electrodes on the brain were used to record visually evoked potentials in response to moving bars at different speeds or to fish of different sizes. Electroretinograms were also recorded to detect when an object or a shadow appeared in the crayfish visual field. Ongoing brain activity is mild under basal conditions, but increases in RMS by approximately 6% in response to bar passage and 12 to 53% in response to fish motionless or swimming in front of the crayfish. When crayfish are free to move, fish swimming in front of them elicit intense brain activity, together with displacement toward them and an attempt to grab them. Visual evoked potentials are elicited by moving objects as small as 1 degree at a distance of 30 cm in air as well as underwater. None of the stimuli used induced evident behavioral responses under our conditions. We conclude that vision-action activities can be divided into (a) vision of irrelevant objects with short lasting electrical activity and no motion in response to it; (b) vision of mildly interesting objects with long-lasting electrical effects, but no motion in response to it; and (c) vision of relevant objects with appropriate motion reaction.

  15. Electrophysiological correlates of face-evoked person knowledge. (United States)

    Taylor, JohnMark; Shehzad, Zarrar; McCarthy, Gregory


    Face recognition includes identifying a face as perceptually familiar and recollecting biographical information, or person-knowledge, associated with the face. The majority of studies examining the neural basis of face recognition have confounded these stages by comparing brain responses evoked by novel and perceptually familiar famous faces. Here, we recorded EEG in two tasks in which subjects viewed two sets of faces that were equally perceptually familiar, but which had differing levels of associated person-knowledge. Our results dissociated the effects of person-knowledge from perceptual familiarity. Faces with associated biographical information elicited a larger ∼600ms centroparietal positivity in both a passive viewing task in which subjects viewed faces without explicitly responding, and an active question-answering task in which subjects indicated whether or not they knew particular facts about the faces. In the question task only, person-knowledge was associated with a negative ERP difference over right posterior scalp over the 170-450ms interval which appeared again at long latency (>900ms).

  16. Towards a neural basis of music-evoked emotions. (United States)

    Koelsch, Stefan


    Music is capable of evoking exceptionally strong emotions and of reliably affecting the mood of individuals. Functional neuroimaging and lesion studies show that music-evoked emotions can modulate activity in virtually all limbic and paralimbic brain structures. These structures are crucially involved in the initiation, generation, detection, maintenance, regulation and termination of emotions that have survival value for the individual and the species. Therefore, at least some music-evoked emotions involve the very core of evolutionarily adaptive neuroaffective mechanisms. Because dysfunctions in these structures are related to emotional disorders, a better understanding of music-evoked emotions and their neural correlates can lead to a more systematic and effective use of music in therapy.

  17. Pudendal somatosensory evoked potentials in normal women

    Directory of Open Access Journals (Sweden)

    Geraldo A. Cavalcanti


    Full Text Available OBJECTIVE: Somatosensory evoked potential (SSEP is an electrophysiological test used to evaluate sensory innervations in peripheral and central neuropathies. Pudendal SSEP has been studied in dysfunctions related to the lower urinary tract and pelvic floor. Although some authors have already described technical details pertaining to the method, the standardization and the influence of physiological variables in normative values have not yet been established, especially for women. The aim of the study was to describe normal values of the pudendal SSEP and to compare technical details with those described by other authors. MATERIALS AND METHODS: The clitoral sensory threshold and pudendal SSEP latency was accomplished in 38 normal volunteers. The results obtained from stimulation performed on each side of the clitoris were compared to ages, body mass index (BMI and number of pregnancies. RESULTS: The values of clitoral sensory threshold and P1 latency with clitoral left stimulation were respectively, 3.64 ± 1.01 mA and 37.68 ± 2.60 ms. Results obtained with clitoral right stimulation were 3.84 ± 1.53 mA and 37.42 ± 3.12 ms, respectively. There were no correlations between clitoral sensory threshold and P1 latency with age, BMI or height of the volunteers. A significant difference was found in P1 latency between nulliparous women and volunteers who had been previously submitted to cesarean section. CONCLUSIONS: The SSEP latency represents an accessible and reproducible method to investigate the afferent pathways from the genitourinary tract. These results could be used as normative values in studies involving genitourinary neuropathies in order to better clarify voiding and sexual dysfunctions in females.

  18. Comparison of the evoked response electrical stimulator and visual analog scale for pain assessment in postoperative patients%体感诱发电位刺激仪和视觉模拟量表用于术后疼痛评估的比较

    Institute of Scientific and Technical Information of China (English)

    刘明娟; 姚明; 黄兵; 朱艳丽; 倪华栋; 过建国; 肖纯; 周煦燕


    目的:通过体感诱发电位刺激仪和视觉模拟量表对术后患者急性疼痛评估的比较,探讨使用体感诱发电位刺激仪进行术后疼痛的评估的可行性.方法:观察美国麻醉医师协会(ASA)Ⅰ~Ⅱ级的手术后患者155例,年龄18 ~ 72岁,分别用体感诱发电位刺激仪和视觉模拟量表对术后患者的急性疼痛进行评估,用SPSS 11.0软件对测得的数据进行统计学分析.结果:体感诱发电位刺激仪和视觉模拟量表的相关系数为0.635 (P< 0.001),两者存在显著正相关关系.结论:体感诱发电位刺激仪和视觉模拟量表有较好的相关性,体感诱发电位刺激仪可用于疼痛评估,有较好的临床应用前景.%Objective To compare the validity of the evoked response electrical stimulator (ERES) with visual analog scale (VAS) in analyzing pain intensity in postoperative patients. Methods 155 patients with ASA Ⅰ-Ⅱ grade, aged 18-72 years, were followed-up within day 1 -3 after surgery. The pain intensity evaluated by ERES and VAS in postoperative patients were recorded. Results There was a significant correlation between VAS and PD in the two groups, the respective coefficient of correlation was 0.635 (P < 0.001). Conclusion There was a well correlation between VAS and ERES in the pain assessment in postoperative patients. It is feasible for ERES to assess pain intensity in postoperative patients.

  19. Audiometria de alta freqüência: estudo com indivíduos audiologicamente normais High-frequency audiometry: study with normal audiological subjects

    Directory of Open Access Journals (Sweden)

    Daniela R. Sahyeb


    Full Text Available Pesquisas recentes apontam a Audiometria Tonal de Alta Freqüência (AT-AF como um instrumento para o diagnóstico precoce de danos auditivos decorrentes de alguns agentes etiológicos principais, como envelhecimento e exposição a drogas ototóxicas e a intensidades elevadas de ruído. OBJETIVO: Apesar de já existirem várias técnicas desenvolvidas para essa avaliação, algumas não se aplicam à rotina clínica, em função da falta de praticidade e, por vezes, falta de consistência nos resultados. Segundo a literatura, ainda estão por emergir uma metodologia adequada a tal avaliação e valores indicados como referência à normalidade. Forma de Estudo: Clínico prospectivo. MATERIAL E MÉTODO: A presente pesquisa observou o comportamento dos limiares auditivos de alta freqüência em indivíduos jovens e audiologicamente normais e analisou variabilidades acústicas, inter e intra-indivíduos, que de acordo com a literatura, podem interferir na estabilidade dos resultados. CONCLUSÃO: Com os dados obtidos, pôde-se estabelecer valores de média, desvio padrão e mediana, além de valores mínimos e máximos para cada freqüência. Os testes estatísticos não identificaram diferenças significantes na maioria das análises realizadas (entre sexo, interaurais, variabilidades acústicas e intra-indivíduos, no mesmo dia de testes. A variabilidade dos resultados entre os exames de um mesmo indivíduo, realizados em dias deferentes de testes, mostrou ser significante, sendo as médias dos limiares no segundo dia sempre melhores que as do primeiro dia.Recent research studies pointed to High-Frequency Audiometry (HFA as a tool for early diagnosis of hearing impairment caused by the main etiological agents, such as aging, exposure to ototoxic drugs, and occupational noise. AIM: Although there are already several techniques developed for this assessment, some of them should not be applied to clinical routine, because of their lack of

  20. Optogenetic stimulation of the cochlear nucleus using channelrhodopsin-2 evokes activity in the central auditory pathway (United States)

    Darrow, Keith N.; Slama, Michaël C. C.; Owoc, Maryanna; Kozin, Elliott; Hancock, Kenneth; Kempfle, Judith; Edge, Albert; Lacour, Stephanie; Boyden, Edward; Polley, Daniel; Brown, M. Christian; Lee, Daniel J.


    Optogenetics has become an important research tool and is being considered as the basis for several neural prostheses. However, few studies have applied optogenetics to the auditory brainstem. This study explored whether optical activation of the cochlear nucleus (CN) elicited responses in neurons in higher centers of the auditory pathway, and it measured the evoked response to optical stimulation. Viral-mediated gene transfer was used to express channelrhodopsin-2 (ChR2) in the mouse CN. Blue light was delivered via an optical fiber placed near the surface of the infected CN and recordings were made in higher-level centers. Optical stimulation evoked excitatory multiunit spiking activity throughout the tonotopic axis of central nucleus of the inferior colliculus (IC) and the auditory cortex (Actx). The pattern and magnitude of IC activity elicited by optical stimulation was comparable to that obtained with a 50 dB SPL acoustic click stimulus. This broad pattern of activity was consistent with histological confirmation of GFP label of cell bodies and axons throughout the CN. Increasing pulse rates up to 320 Hz did not significantly affect threshold or bandwidth of the IC responses, but rates higher than 50 Hz resulted in desynchronized activity. Optical stimulation also evoked an auditory brainstem response, which had a simpler waveform than the response to acoustic stimulation. Control cases showed no responses to optical stimulation. These data suggest that optogenetic control of central auditory neurons is feasible, but opsins with faster channel kinetics will be necessary to convey information in rates typical of many auditory signals. PMID:25481416

  1. Optogenetic stimulation of the cochlear nucleus using channelrhodopsin-2 evokes activity in the central auditory pathways. (United States)

    Darrow, Keith N; Slama, Michaël C C; Kozin, Elliott D; Owoc, Maryanna; Hancock, Kenneth; Kempfle, Judith; Edge, Albert; Lacour, Stephanie; Boyden, Edward; Polley, Daniel; Brown, M Christian; Lee, Daniel J


    Optogenetics has become an important research tool and is being considered as the basis for several neural prostheses. However, few studies have applied optogenetics to the auditory brainstem. This study explored whether optical activation of the cochlear nucleus (CN) elicited responses in neurons in higher centers of the auditory pathway and whether it elicited an evoked response. Viral-mediated gene transfer was used to express channelrhodopsin-2 (ChR2) in the mouse CN. Blue light was delivered via an optical fiber placed near the surface of the infected CN and recordings were made in higher-level centers. Optical stimulation evoked excitatory multiunit spiking activity throughout the tonotopic axis of the central nucleus of the inferior colliculus (IC) and the auditory cortex (Actx). The pattern and magnitude of IC activity elicited by optical stimulation was comparable to that obtained with a 50dB SPL acoustic click. This broad pattern of activity was consistent with histological confirmation of green fluorescent protein (GFP) label of cell bodies and axons throughout the CN. Increasing pulse rates up to 320Hz did not significantly affect threshold or bandwidth of the IC responses, but rates higher than 50Hz resulted in desynchronized activity. Optical stimulation also evoked an auditory brainstem response, which had a simpler waveform than the response to acoustic stimulation. Control cases showed no responses to optical stimulation. These data suggest that optogenetic control of central auditory neurons is feasible, but opsins with faster channel kinetics may be necessary to convey information at rates typical of many auditory signals.

  2. Investigating the periodicity of transient-evoked otoacoustic emission envelopes

    DEFF Research Database (Denmark)

    Verhulst, Sarah


    This study investigates the cochlear origin of the multiple temporal lobes that are often observed in the transient-evoked otoacoustic emission (TEOAE) envelope. This "waxing and waning" of the OAE amplitude can be observed in tone-burst (TB) OAEs and sometimes also in click-evoked (CE) OAEs. TBOAE...... and the middle-ear boundary may contribute to the TBOAE envelope periodicity, but were not the main modulation component in waxing and waning of the investigated TBOAEs....

  3. A programmable acoustic stimuli and auditory evoked potential measurement system for objective tinnitus diagnosis research. (United States)

    Ku, Yunseo; Ahn, Joong Woo; Kwon, Chiheon; Suh, Myung-Whan; Lee, Jun Ho; Oh, Seung Ha; Kim, Hee Chan


    This paper presents the development of a single platform that records auditory evoked potential synchronized to specific acoustic stimuli of the gap prepulse inhibition method for objective tinnitus diagnosis research. The developed system enables to program various parameters of the generated acoustic stimuli. Moreover, only by simple filter modification, the developed system provides high flexibility to record not only short latency auditory brainstem response but also late latency auditory cortical response. The adaptive weighted averaging algorithm to minimize the time required for the experiment is also introduced. The results show that the proposed algorithm can reduce the number of the averaging repetitions to 70% compared with conventional ensemble averaging method.

  4. Calcium transient evoked by nicotine in isolated rat vagal pulmonary sensory neurons. (United States)

    Xu, Jennings; Yang, Wenbin; Zhang, Guangfan; Gu, Qihai; Lee, Lu-Yuan


    It has been shown that inhaled cigarette smoke activates vagal pulmonary C fibers and rapidly adapting receptors (RARs) in the airways and that nicotine contained in the smoke is primarily responsible. This study was carried out to determine whether nicotine alone can activate pulmonary sensory neurons isolated from rat vagal ganglia; the response of these neurons was determined by fura-2-based ratiometric Ca(2+) imaging. The results showed: 1) Nicotine (10(-4) M, 20 s) evoked a transient increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in 175 of the 522 neurons tested (Delta[Ca(2+)](i) = 142.2 +/- 12.3 nM); the response was reproducible, with a small reduction in peak amplitude in the same neurons when the challenge was repeated 20 min later. 2) A majority (59.7%) of these nicotine-sensitive neurons were also activated by capsaicin (10(-7) M). 3) 1,1-Dimethyl-4-phenylpiperazinium iodide (DMPP; 10(-4) M, 20 s), a selective agonist of the neuronal nicotinic acetylcholine receptors (NnAChRs), evoked a pattern of response similar to that of nicotine. 4) The responses to nicotine and DMPP were either totally abrogated or markedly attenuated by hexamethonium (10(-4) M). 5) In anesthetized rats, right atrial bolus injection of nicotine (75-200 mug/kg) evoked an immediate (latency <1-2 s) and intense burst of discharge in 47.8% of the pulmonary C-fiber endings and 28.6% of the RARs tested. In conclusion, nicotine exerts a direct stimulatory effect on vagal pulmonary sensory nerves, and the effect is probably mediated through an activation of the NnAChRs expressed on the membrane of these neurons.

  5. Paying attention to orthography: A visual evoked potential study

    Directory of Open Access Journals (Sweden)

    Anthony Thomas Herdman


    Full Text Available In adult readers, letters and words are rapidly identified within visual networks to allow for efficient reading abilities. Neuroimaging studies of orthography have mostly used words and letter strings that recruit many hierarchical levels in reading. Understanding how single letters are processed could provide further insight into orthographic processing. The present study investigated orthographic processing using single letters and pseudoletters when adults were encouraged to pay attention to or away from orthographic features. We measured evoked potentials (EPs to single letters and pseudoletters from adults while they performed an orthographic-discrimination task (letters vs. pseudoletters, a colour-discrimination task (red vs. blue, and a target-detection task (respond to #1 and #2. Larger and later peaking N1 responses (~170ms and larger P2 responses (~250 ms occurred to pseudoletters as compared to letters. This reflected greater visual processing for pseudoletters. Dipole analyses localized this effect to bilateral fusiform and inferior temporal cortices. Moreover, this letter-pseudoletter difference was not modulated by task and thus indicates that directing attention to or away from orthographic features didn’t affect early visual processing of single letters or pseudoletters within extrastriate regions. Paying attention to orthography or colour as compared to disregarding the stimuli (target-detection task elicited selection negativities at about 175 ms, which were followed by a classical N2-P3 complexes. This indicated that the tasks sufficiently drew participant’s attention to and away from the stimuli. Together these findings revealed that visual processing of single letters and pseudoletters, in adults, appeared to be sensory-contingent and independent of paying attention to stimulus features (e.g., orthography or colour.

  6. Evolution of separate predation- and defence-evoked venoms in carnivorous cone snails. (United States)

    Dutertre, Sébastien; Jin, Ai-Hua; Vetter, Irina; Hamilton, Brett; Sunagar, Kartik; Lavergne, Vincent; Dutertre, Valentin; Fry, Bryan G; Antunes, Agostinho; Venter, Deon J; Alewood, Paul F; Lewis, Richard J


    Venomous animals are thought to inject the same combination of toxins for both predation and defence, presumably exploiting conserved target pharmacology across prey and predators. Remarkably, cone snails can rapidly switch between distinct venoms in response to predatory or defensive stimuli. Here, we show that the defence-evoked venom of Conus geographus contains high levels of paralytic toxins that potently block neuromuscular receptors, consistent with its lethal effects on humans. In contrast, C. geographus predation-evoked venom contains prey-specific toxins mostly inactive at human targets. Predation- and defence-evoked venoms originate from the distal and proximal regions of the venom duct, respectively, explaining how different stimuli can generate two distinct venoms. A specialized defensive envenomation strategy is widely evolved across worm, mollusk and fish-hunting cone snails. We propose that defensive toxins, originally evolved in ancestral worm-hunting cone snails to protect against cephalopod and fish predation, have been repurposed in predatory venoms to facilitate diversification to fish and mollusk diets.

  7. Evoked potentials are useful for diagnosis of neuromyelitis optica spectrum disorder. (United States)

    Ohnari, Keiko; Okada, Kazumasa; Takahashi, Toshiyuki; Mafune, Kosuke; Adachi, Hiroaki


    Neuromyelitis optica spectrum disorder (NMOSD) has been differentiated from relapsing-remitting multiple sclerosis (RRMS) by clinical, laboratory, and pathological findings, including the presence of the anti-aquaporin 4 antibody. Measurement of evoked potentials (EPs) is often used for the diagnosis of RRMS, although the possibility of applying EPs to the diagnosis of NMOSD has not been investigated in detail. Eighteen patients with NMOSD and 28 patients with RRMS were included in this study. The patients' neurological symptoms and signs were examined and their EPs were recorded. Characteristic findings were absence of visual evoked potentials and absence of motor evoked potentials in the lower extremities in patients with NMOSD, and a delay in these potentials in patients with RRMS. Most patients with NMOSD did not present abnormal subclinical EPs, whereas many patients with RRMS did. None of the patients with NMOSD showed abnormalities in auditory brainstem responses. NMOSD can be differentiated from RRMS by EP data obtained in the early stages of these diseases.

  8. Head movements evoked in alert rhesus monkey by vestibular prosthesis stimulation: implications for postural and gaze stabilization.

    Directory of Open Access Journals (Sweden)

    Diana E Mitchell

    Full Text Available The vestibular system detects motion of the head in space and in turn generates reflexes that are vital for our daily activities. The eye movements produced by the vestibulo-ocular reflex (VOR play an essential role in stabilizing the visual axis (gaze, while vestibulo-spinal reflexes ensure the maintenance of head and body posture. The neuronal pathways from the vestibular periphery to the cervical spinal cord potentially serve a dual role, since they function to stabilize the head relative to inertial space and could thus contribute to gaze (eye-in-head + head-in-space and posture stabilization. To date, however, the functional significance of vestibular-neck pathways in alert primates remains a matter of debate. Here we used a vestibular prosthesis to 1 quantify vestibularly-driven head movements in primates, and 2 assess whether these evoked head movements make a significant contribution to gaze as well as postural stabilization. We stimulated electrodes implanted in the horizontal semicircular canal of alert rhesus monkeys, and measured the head and eye movements evoked during a 100 ms time period for which the contribution of longer latency voluntary inputs to the neck would be minimal. Our results show that prosthetic stimulation evoked significant head movements with latencies consistent with known vestibulo-spinal pathways. Furthermore, while the evoked head movements were substantially smaller than the coincidently evoked eye movements, they made a significant contribution to gaze stabilization, complementing the VOR to ensure that the appropriate gaze response is achieved. We speculate that analogous compensatory head movements will be evoked when implanted prosthetic devices are transitioned to human patients.

  9. Influence of naloxone on catecholamine release evoked by nicotinic receptor stimulation in the isolated rat adrenal gland. (United States)

    Kim, Ok-Min; Lim, Geon-Han; Lim, Dong-Yoon


    The present study was designed to investigate the effect of naloxone, a well known opioid antagonist, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal glands, and to establish its mechanism of action. Naloxone (10(-6) approximately 10(-5) M), perfused into an adrenal vein for 60 min, produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh (5.32 x 10(-3) M), high K+ (5.6 x 10(-2) M), DMPP (10(-4) M) and McN-A-343 (10(-4) M). Naloxone itself also failed to affect the basal CA output. In adrenal glands loaded with naloxone (3 x 10(-6) M), the CA secretory responses evoked by Bay-K-8644, an activator of L-type Ca2+ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic Ca(2+)-ATPase, were also inhibited. In the presence of met-enkephalin (5 x 10(-6) M), a well known opioid agonist, the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Taken together, these results suggest that naloxone greatly inhibits the CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that these inhibitory effects of naloxone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of Ca2+ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

  10. Vestibular receptors contribute to cortical auditory evoked potentials. (United States)

    Todd, Neil P M; Paillard, Aurore C; Kluk, Karolina; Whittle, Elizabeth; Colebatch, James G


    Acoustic sensitivity of the vestibular apparatus is well-established, but the contribution of vestibular receptors to the late auditory evoked potentials of cortical origin is unknown. Evoked potentials from 500 Hz tone pips were recorded using 70 channel EEG at several intensities below and above the vestibular acoustic threshold, as determined by vestibular evoked myogenic potentials (VEMPs). In healthy subjects both auditory mid- and long-latency auditory evoked potentials (AEPs), consisting of Na, Pa, N1 and P2 waves, were observed in the sub-threshold conditions. However, in passing through the vestibular threshold, systematic changes were observed in the morphology of the potentials and in the intensity dependence of their amplitude and latency. These changes were absent in a patient without functioning vestibular receptors. In particular, for the healthy subjects there was a fronto-central negativity, which appeared at about 42 ms, referred to as an N42, prior to the AEP N1. Source analysis of both the N42 and N1 indicated involvement of cingulate cortex, as well as bilateral superior temporal cortex. Our findings are best explained by vestibular receptors contributing to what were hitherto considered as purely auditory evoked potentials and in addition tentatively identify a new component that appears to be primarily of vestibular origin.

  11. A Comprehensive Review on Methodologies Employed for Visual Evoked Potentials. (United States)

    Kothari, Ruchi; Bokariya, Pradeep; Singh, Smita; Singh, Ramji


    Visual information is fundamental to how we appreciate our environment and interact with others. The visual evoked potential (VEP) is among those evoked potentials that are the bioelectric signals generated in the striate and extrastriate cortex when the retina is stimulated with light which can be recorded from the scalp electrodes. In the current paper, we provide an overview of the various modalities, techniques, and methodologies which have been employed for visual evoked potentials over the years. In the first part of the paper, we cast a cursory glance on the historical aspect of evoked potentials. Then the growing clinical significance and advantages of VEPs in clinical disorders have been briefly described, followed by the discussion on the earlier and currently available methods for VEPs based on the studies in the past and recent times. Next, we mention the standards and protocols laid down by the authorized agencies. We then summarize the recently developed techniques for VEP. In the concluding section, we lay down prospective research directives related to fundamental and applied aspects of VEPs as well as offering perspectives for further research to stimulate inquiry into the role of visual evoked potentials in visual processing impairment related disorders.

  12. Cell surface domain specific postsynaptic currents evoked by identified GABAergic neurones in rat hippocampus in vitro. (United States)

    Maccaferri, G; Roberts, J D; Szucs, P; Cottingham, C A; Somogyi, P


    of IPSCs evoked by BiCs and O-BiCs showed the largest cell to cell variation, and a single interneurone could evoke both small and slow as well as large and relatively fast IPSCs. 6. The kinetic properties of the somatically recorded postsynaptic current are correlated with the innervated cell surface domain. A significant correlation of rise and decay times for the overall population of unitary IPSCs suggests that electrotonic filtering of distal responses is a major factor for the location and cell type specific differences of unitary IPSCs, but molecular heterogeneity of postsynaptic GABAA receptors may also contribute to the observed kinetic differences. Furthermore, domain specific differences in the short-term plasticity of the postsynaptic response indicate a differentiation of interneurones in activity-dependent responses.

  13. The effect of Jujuboside A on the evoked field potentials of Granule cells in dentate gyrus

    Institute of Scientific and Technical Information of China (English)

    封洲燕; 郑筱祥


    Jujuboside A( JuA) is a main component of Jujubogenin extracted from the seeds of Ziziphus.The authors have not seen report on JuA's direct effect on the neruons of the central nervous system.This study aimed to assess the effect of JuA on paried-pulse responses of dentate gyrus granule cells in urethaneanasesthetized rats,used intracerebroventricular(i.c.v.) JuA to mimic in vitro tath conditions in vivo.Pariedpulse stimuli with 80ms interpulse interval were used to stimulate the perforant pathway.Evoked responses first responses,the slopoes of excitatory postsynaptic potential(EPSP1) and the amplitudes of population spike (PS1) decreased significantly after administration of JuA while the PS1 latencies increased significantly.In the second responses.the EPSP2 slops and PS2 latencies were changed similarly to those of the first ones.but PS2 amplitudes increased.The results showed that JuA may have some inhibitory effect on the granule cell excitability mediated by presynaptic mechanism but may have little effect on the excitability mediated by postsynaptic mechanism since the second evoked N-methyl-D-aspartic mediating paired-pulse facilitation is a postsynaptic mechanism.

  14. Prejunctional inhibition of sympathetically evoked pupillary dilation in cats by activation of histamine H3 receptors. (United States)

    Koss, M C; Hey, J A


    Frequency-dependent pupillary dilations were evoked by electrical stimulation of the pre- or post-ganglionic cervical sympathetic nerve (sympatho-excitation) or the hypothalamus (parasympatho-inhibition) in sympathectomized anesthetized cats. Systemic administration of the selective histamine H3 receptor agonist (R)-alpha-methylhistamine (R alpha MeHA) produced a dose-dependent depression of mydriasis due to direct neural sympathetic activation but had no effect on responses elicited by parasympathetic withdrawal. The histamine H2 receptor agonist, dimaprit, was inactive. R alpha MeHA was much more effective in depressing sympathetic responses obtained at lower frequencies when compared to higher frequencies of stimulation. Responses evoked both pre- and postganglionically were inhibited by R alpha MeHA. This peripheral sympatho-inhibitory action of R alpha MeHA was antagonized by the histamine H3 receptor blocker thioperamide but not by intravenous pretreatment with the histamine H1 receptor antagonist chlorpheniramine. Histamine H2 receptor blockers cimetidine and ranitidine were also without effect. R alpha MeHA did not depress pupillary responses elicited by i.v. (-)-adrenaline. The results demonstrate that histamine H3 receptors modulate sympathetic activation of the iris at a site proximal to the iris dilator muscle. The predominant mechanism of action appears to the prejunctional inhibition of noradrenaline release from postganglionic sympathetic nerve endings. However, a concomitant ganglionic inhibitory action cannot be excluded.

  15. The effect of Jujuboside A on the evoked field potentials of granule cells in dentate gyrus

    Institute of Scientific and Technical Information of China (English)

    封洲燕; 郑筱祥


    Jujuboside A (JuA) is a main component of Jujubogenin extracted from the seeds of Ziziphus. The authors have not seen any report on JuA's direct effect on the neurons of the central nervous system. This study aimed to assess the effect of JuA on paired-pulse responses of dentate gyrus granule cells in urethane-anaesthetized rats, used intracerebroventricular (i.c.v.) JuA to mimic in vitro bath conditions in vivo. Paired-pulse stimuli with 80ms interpulse interval were used to stimulate the perforant pathway. Evoked responses were recorded in the dentate gyrus cell layer after i.c.v. administration of 0.9% normal saline or JuA. In the first responses, the slopes of excitatory postsynaptic potential (EPSP1) and the amplitudes of population spike (PS1) decreased significantly after administration of JuA while the PS1 latencies increased significantly. In the second responses, the EPSP2 slopes and PS2 latencies were changed similarly to those of the first ones, but PS2 amplitudes increased. The results showed that JuA may have some inhibitory effect on the granule cell excitability mediated by presynaptic mechanism but may have little effect on the excitability mediated by postsynaptic mechanism since the second evoked N-methyl-D-aspartic mediating paired-pulse facilitation is a postsynaptic mechanism.

  16. 离体脊髓同侧中央管周围区电刺激诱发运动神经元突触反应%Synaptic responses of motoneurons evok ed by ipsilateral pericentral canal zone stimula-t ion in spinal cord in vitro

    Institute of Scientific and Technical Information of China (English)

    秦雯; 郑超; 王邦安; 汪萌芽


    目的:探讨新生大鼠脊髓切片同侧中央管周围区(iPCC)向运动神经元(MN)兴奋性突触传递的细胞电生理特性。方法:应用新生大鼠(8~14 d)脊髓切片MN细胞内记录技术,观察iPCC局部电刺激在MN所诱发的突触反应。结果:在14个测试的MN,观察到iPCC电刺激可在11个MN上诱发兴奋性突触后电位(iPCC-EPSP),在1个MN上诱发抑制性突触后电位( iPCC-IPSP ),在2个 MN上诱发iPCC-EPSP后复合有iPCC-IPSP的反应。 iPCC-EPSP不仅具有刺激强度依赖性和膜电位依赖性,而且可以被低钙高镁溶液或TTX(0.1μmol/L)可逆性取消。荷包牡丹碱和士的宁能增大iPCC-EPSP,但谷氨酸受体拮抗剂 APV(30μmol/L)和DNQX(1μmol/L)仅部分抑制iPCC-EPSP。结论:iPCC的激活可通过兴奋性突触传递调制MN的活动,其介导递质除谷氨酸外,可能还有其他递质的参与。%Objective:To explore the cellular electrophysiological proper-ties of the excitatory synaptic transmissions from the ipsilateral pericentral canal(iPCC)zone to motoneurons(MN)in neonatal rat spinal cord slices. Methods: The intracellular recording techniques were performed in MN of spinal cord slices isolated from neonatal rats(8-14 days old),and focal e-lectrical stimulation of the iPCC zone was applied to evoke the synaptic responses.Results: In 14 MNs tested, excitatory postsynaptic potentials ( EPSPs) ,inhibitory postsynaptic potentials ( IPSPs) and EPSP followed by IPSP were elicited by iPCC stimulation ( iPCC-EPSPs or iPCC-IPSPs) in 11,1 and 2 MNs, respectively.The iPCC-EPSPs were sensitive to low Ca2+/high Mg2+solution or tetrodotoxin and presented with stimulus in-tensity-dependent and membrane potential-dependent properties.The iPCC-EPSPs were increased by bicuculline and strychnine,but only par-tially eliminated by the perfusion of APV(30 mol/L),and DNQX(1 mol/L) ,the antagonists of glutamate receptors

  17. 鼓室成形术病人面神经诱发肌电位反应与神经肌肉阻滞程度间的相关性%Correlation between facial nerve evoked-electromyographic responses and degree of neuromuscular blockade in patients undergoing tympanoplasty

    Institute of Scientific and Technical Information of China (English)

    徐静; 蔡一榕; 陈莲华; 迟放鲁


    目的 探讨面神经诱发肌电位(EEMG)反应与神经肌肉阻滞(NMB)程度间的相关性.方法 拟行鼓室成形术病人40例,分为面神经暴露组(A组,n=16)和面神经非暴露组(B组,n=24),术中同步行面神经EEMG监测和外周NMB程度监测.不同NMB程度(0、25%、50%、75%、100%)时测定面神经EEMG刺激阈值和固定刺激强度下EEMG振幅.EEMG的刺激阈值和振幅与NMB程度间进行等级相关分析.结果 NMB≥75%时,4例病人未能诱发EEMG;A组和B组EEMG刺激阈值与NMB程度间的相关系数分别为0.38和0.26(P<0.01),EEMG振幅与NMB程度间的相关系数分别为-0.66和-0.55(P<0.01).在各个NMB水平,A组EEMG刺激阈值低于B组(P<0.01);随着NMB程度的加深,EEMG刺激阈值逐渐增加,EEMG振幅逐渐降低(P<0.05).结论 鼓室成形术病人面神经EEMG刺激阈值与NMB程度呈正相关,EEMG振幅与NMB程度呈负相关.%Objective To evaluate the correlation between facial nerve evoked-electromyographic (EEMG)responses and degree of neuromuscular blockade(NMB)during tympanoplasty.Methods Forty ASA ⅠorⅡpatients of both sexes aged 20-64 yr undergoing tympanoplasty were divided into 2 groups:group A facial nerve exposed(n=16)and group B facial nerve unexposed(n=24).Anesthesia was induced with midazolam 2-3 mg.fentanyl 2 μg/kg and propofol 2 mg/kg.Tracheal intubation was facilitated with succinyl choline 2 mg/kg.The patients were mechanically ventilated(VT 8-10 ml/kg,RR 10-12 bpm).PET CO2 was maintained at 35-40 mm Hg.Anesthesia was maintained with isoflurane inhalation,remifentanil infusion(0.2 μg·kg-1·min-1)and rocuronium.Controlled hypotension was performed during operation with nitroglycerin.MAP was maintained at 55-65 mm Hg.ECG,BP,HR,SpO2 and PET CO2 were monitored.NMB was monitored by responses of adductor pollicis muscle to stimulation of ulna nerve using TOF-Watch (R)SX Monitor(Organon,Netherlands).The facial nerve EEMG responses were measured when the degree of NMB(T1

  18. Simultaneously-evoked auditory potentials (SEAP): A new method for concurrent measurement of cortical and subcortical auditory-evoked activity. (United States)

    Slugocki, Christopher; Bosnyak, Daniel; Trainor, Laurel J


    Recent electrophysiological work has evinced a capacity for plasticity in subcortical auditory nuclei in human listeners. Similar plastic effects have been measured in cortically-generated auditory potentials but it is unclear how the two interact. Here we present Simultaneously-Evoked Auditory Potentials (SEAP), a method designed to concurrently elicit electrophysiological brain potentials from inferior colliculus, thalamus, and primary and secondary auditory cortices. Twenty-six normal-hearing adult subjects (mean 19.26 years, 9 male) were exposed to 2400 monaural (right-ear) presentations of a specially-designed stimulus which consisted of a pure-tone carrier (500 or 600 Hz) that had been amplitude-modulated at the sum of 37 and 81 Hz (depth 100%). Presentation followed an oddball paradigm wherein the pure-tone carrier was set to 500 Hz for 85% of presentations and pseudo-randomly changed to 600 Hz for the remaining 15% of presentations. Single-channel electroencephalographic data were recorded from each subject using a vertical montage referenced to the right earlobe. We show that SEAP elicits a 500 Hz frequency-following response (FFR; generated in inferior colliculus), 80 (subcortical) and 40 (primary auditory cortex) Hz auditory steady-state responses (ASSRs), mismatch negativity (MMN) and P3a (when there is an occasional change in carrier frequency; secondary auditory cortex) in addition to the obligatory N1-P2 complex (secondary auditory cortex). Analyses showed that subcortical and cortical processes are linked as (i) the latency of the FFR predicts the phase delay of the 40 Hz steady-state response, (ii) the phase delays of the 40 and 80 Hz steady-state responses are correlated, and (iii) the fidelity of the FFR predicts the latency of the N1 component. The SEAP method offers a new approach for measuring the dynamic encoding of acoustic features at multiple levels of the auditory pathway. As such, SEAP is a promising tool with which to study how

  19. The involvement of prostaglandin E2 in interleukin-1β evoked anorexia is strain dependent. (United States)

    Nilsson, Anna; Elander, Louise; Hallbeck, Martin; Örtegren Kugelberg, Unn; Engblom, David; Blomqvist, Anders


    From experiments in mice in which the prostaglandin E2 (PGE2) synthesizing enzyme mPGES-1 was genetically deleted, as well as from experiments in which PGE2 was injected directly into the brain, PGE2 has been implicated as a mediator of inflammatory induced anorexia. Here we aimed at examining which PGE2 receptor (EP1-4) that was critical for the anorexic response to peripherally injected interleukin-1β (IL-1β). However, deletion of neither EP receptor in mice, either globally (for EP1, EP2, and EP3) or selectively in the nervous system (EP4), had any effect on the IL-1β induced anorexia. Because these mice were all on a C57BL/6 background, whereas previous observations demonstrating a role for induced PGE2 in IL-1β evoked anorexia had been carried out on mice on a DBA/1 background, we examined the anorexic response to IL-1β in mice with deletion of mPGES-1 on a C57BL/6 background and a DBA/1 background, respectively. We confirmed previous findings that mPGES-1 knock-out mice on a DBA/1 background displayed attenuated anorexia to IL-1β; however, mice on a C57BL/6 background showed the same profound anorexia as wild type mice when carrying deletion of mPGES-1, while displaying almost normal food intake after pretreatment with a cyclooxygenase-2 inhibitor. We conclude that the involvement of induced PGE2 in IL-1β evoked anorexia is strain dependent and we suggest that different routes that probably involve distinct prostanoids exist by which inflammatory stimuli may evoke an anorexic response and that these routes may be of different importance in different strains of mice.

  20. Neuronal Rac1 is required for learning-evoked neurogenesis

    DEFF Research Database (Denmark)

    Haditsch, Ursula; Anderson, Matthew P; Freewoman, Julia


    neurons for normal synaptic plasticity in vivo, and here we show that selective loss of neuronal Rac1 also impairs the learning-evoked increase in neurogenesis in the adult mouse hippocampus. Earlier work has indicated that experience elevates the abundance of adult-born neurons in the hippocampus...... primarily by enhancing the survival of neurons produced just before the learning event. Loss of Rac1 in mature projection neurons did reduce learning-evoked neurogenesis but, contrary to our expectations, these effects were not mediated by altering the survival of young neurons in the hippocampus. Instead......, loss of neuronal Rac1 activation selectively impaired a learning-evoked increase in the proliferation and accumulation of neural precursors generated during the learning event itself. This indicates that experience-induced alterations in neurogenesis can be mechanistically resolved into two effects: (1...

  1. Temporal resolution in the hearing system and auditory evoked potentials

    DEFF Research Database (Denmark)

    Miller, Lee; Beedholm, Kristian


    3pAB5. Temporal resolution in the hearing system and auditory evoked potentials. Kristian Beedholm Institute of Biology,University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark,, Lee A. Miller Institute of Biology,University of Southern Denmark, Campusvej 55, 5230...... Odense M, Denmark, lee@biology.sdu.dkA popular type of investigation with auditory evoked potentials AEP consists of mapping the dependency of the envelope followingresponse to the AM frequency. This results in what is called the modulation rate transfer function MRTF. The physiologicalinterpretation...... of the MRTF is not straight forward, but is often used as a measure of the ability of the auditory system to encodetemporal changes. It is, however, shown here that the MRTF must depend on the waveform of the click-evoked AEP ceAEP, whichdoes not relate directly to temporal resolution. The theoretical...

  2. Stimulator with arbitrary waveform for auditory evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Eletrica (DEE), Nucleo de Estudos e Pesquisa em Engenharia Biomedica NEPEB, Av. Ant. Carlos, 6627, sala 2206, Pampulha, Belo Horizonte, MG, 31.270-901 (Brazil)


    The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential.

  3. The effects of curiosity-evoking events on activity enjoyment. (United States)

    Isikman, Elif; MacInnis, Deborah J; Ülkümen, Gülden; Cavanaugh, Lisa A


    Whereas prior literature has studied the positive effects of curiosity-evoking events that are integral to focal activities, we explore whether and how a curiosity-evoking event that is incidental to a focal activity induces negative outcomes for enjoyment. Four experiments and 1 field study demonstrate that curiosity about an event that is incidental to an activity in which individuals are engaged, significantly affects enjoyment of a concurrent activity. The reason why is that curiosity diverts attention away from the concurrent activity and focuses attention on the curiosity-evoking event. Thus, curiosity regarding an incidental event decreases enjoyment of a positive focal activity but increases enjoyment of a negative focal activity.

  4. [A Case of Left Vertebral Artery Aneurysm Showing Evoked Potentials on Bilateral Electrode by the Left Vagus Nerve Stimulation to Electromyographic Tracheal Tube]. (United States)

    Kadoya, Tatsuo; Uehara, Hirofumi; Yamamoto, Toshinori; Shiraishi, Munehiro; Kinoshita, Yuki; Joyashiki, Takeshi; Enokida, Kengo


    Previously, we reported a case of brainstem cavernous hemangioma showing false positive responses to electromyographic tracheal tube (EMG tube). We concluded that the cause was spontaneous respiration accompanied by vocal cord movement. We report a case of left vertebral artery aneurysm showing evoked potentials on bilateral electrodes by the left vagus nerve stimulation to EMG tube. An 82-year-old woman underwent clipping of a left unruptured vertebral artery-posterior inferior cerebellar artery aneurysm. General anesthesia was induced with remifentanil, propofol and suxamethonium, and was maintained with oxygen, air, remifentanil and propofol. We monitored somatosensory evoked potentials, motor evoked potentials, and electromyogram of the vocal cord. When the manipulation reached brainstem and the instrument touched the left vagus nerve, evoked potentials appeared on bilateral electrodes. EMG tube is equipped with two electrodes on both sides. We concluded that the left vagus nerve stimulation generated evoked potentials of the left laryngeal muscles, and they were simultaneously detected as potential difference between two electrodes on both sides. EMG tube is used to identify the vagus nerve. However, it is necessary to bear in mind that each vagus nerve stimulation inevitably generates evoked potentials on bilateral electrodes.

  5. Towards an optimization of stimulus parameters for brain-computer interfaces based on steady state visual evoked potentials.

    Directory of Open Access Journals (Sweden)

    Anna Duszyk

    Full Text Available Efforts to construct an effective brain-computer interface (BCI system based on Steady State Visual Evoked Potentials (SSVEP commonly focus on sophisticated mathematical methods for data analysis. The role of different stimulus features in evoking strong SSVEP is less often considered and the knowledge on the optimal stimulus properties is still fragmentary. The goal of this study was to provide insight into the influence of stimulus characteristics on the magnitude of SSVEP response. Five stimuli parameters were tested: size, distance, colour, shape, and presence of a fixation point in the middle of each flickering field. The stimuli were presented on four squares on LCD screen, with each square highlighted by LEDs flickering with different frequencies. Brighter colours and larger dimensions of flickering fields resulted in a significantly stronger SSVEP response. The distance between stimulation fields and the presence or absence of the fixation point had no significant effect on the response. Contrary to a popular belief, these results suggest that absence of the fixation point does not reduce the magnitude of SSVEP response. However, some parameters of the stimuli such as colour and the size of the flickering field play an important role in evoking SSVEP response, which indicates that stimuli rendering is an important factor in building effective SSVEP based BCI systems.

  6. Comparison of the pattern reversal visual evoked potential mediated by separate cone systems

    DEFF Research Database (Denmark)

    Johnsen, B; Frederiksen, J.L.; Larsson, H.B.


    With the purpose of recording responses mediated by the 3 cone systems visual evoked potentials (VEPs) were elicited by the reversal of monochromatic checkerboards superimposed upon strong monochromatic backgrounds (yellow, purple and blue-green). The sensitivity to light of various wave lengths...... were measured as the reciprocal of the intensity necessary to elicit a VEP amplitude of 3 microV. The spectral sensitivity curves based on this VEP amplitude criterion in the presence of blue-green, purple and yellow adaptation showed peak sensitivities in the red, the green and the blue part...

  7. Evaluation of New Methods for Artifacts Rejection in Evoked Auditory Steady-State Potentials

    Directory of Open Access Journals (Sweden)

    Cyndi González Alfonso


    Full Text Available This paper presents two alternative methods to the traditional method of artifact rejectionequipment currently used in evoked potential recording steady state (ASSR in order to improveefficiency based on the use of a larger number of individual records. The first method proposedis to replace the traditional use of rejection threshold amplitude, while the second version is afaster implementation of the weighted averaging used today, which is applicable also in thetransient Auditory Brainstem Response (ABR. These changes have been made in order toimplement these methods in a real time microprocessor.

  8. Brain evoked potential use in a physical medicine and rehabilitation setting. (United States)

    Rappaport, M; Hopkins, K; Hall, K; Belleza, T; Berrol, S


    The objective of this effort was to explore the use of evoked potential (EP) procedure on a head injury unit in a Department of Physical Medicine and Rehabilitation. The method employed both auditory and visual stimulation presented bilaterally to various patients. Recordings of the brain's responses to such stimulation were obtained. Results permitted evaluation of brain stem, subcortical and cortical functioning, ipsilaterally, contralaterally, and bilaterally. EP data provided useful information for patient assessment and rehabilitation planning for head injured patients--particularly for those who were unable to cooperate in their own examination.

  9. Assessment of an ICA-based noise reduction method for multi-channel auditory evoked potentials (United States)

    Mirahmadizoghi, Siavash; Bell, Steven; Simpson, David


    In this work a new independent component analysis (ICA) based method for noise reduction in evoked potentials is evaluated on for auditory late responses (ALR) captured with a 63-channel electroencephalogram (EEG) from 10 normal-hearing subjects. The performance of the new method is compared with a single channel alternative in terms of signal to noise ratio (SNR), the number of channels with an SNR above an empirically derived statistical critical value and an estimate of hearing threshold. The results show that the multichannel signal processing method can significantly enhance the quality of the signal and also detected hearing thresholds significantly lower than with the single channel alternative.

  10. High frequency bone conduction auditory evoked potentials in the guinea pig: Assessing cochlear injury after ossicular chain manipulation. (United States)

    Bergin, M J; Bird, P A; Vlajkovic, S M; Thorne, P R


    Permanent high frequency (>4 kHz) sensorineural hearing loss following middle ear surgery occurs in up to 25% of patients. The aetiology of this loss is poorly understood and may involve transmission of supra-physiological forces down the ossicular chain to the cochlea. Investigating the mechanisms of this injury using animal models is challenging, as evaluating cochlear function with evoked potentials is confounded when ossicular manipulation disrupts the normal air conduction (AC) pathway. Bone conduction (BC) using clinical bone vibrators in small animals is limited by poor transducer output at high frequencies sensitive to trauma. The objectives of the present study were firstly to evaluate a novel high frequency bone conduction transducer with evoked auditory potentials in a guinea pig model, and secondly to use this model to investigate the impact of middle ear surgical manipulation on cochlear function. We modified a magnetostrictive device as a high frequency BC transducer and evaluated its performance by comparison with a calibrated AC transducer at frequencies up to 32 kHz using the auditory brainstem response (ABR), compound action potential (CAP) and summating potential (SP). To mimic a middle ear traumatising stimulus, a rotating bur was brought in to contact with the incudomalleal complex and the effect on evoked cochlear potentials was observed. BC-evoked potentials followed the same input-output function pattern as AC potentials for all ABR frequencies. Deterioration in CAP and SP thresholds was observed after ossicular manipulation. It is possible to use high frequency BC to evoke responses from the injury sensitive basal region of the cochlea and so not rely on AC with the potential confounder of conductive hearing loss. Ongoing research explores how these findings evolve over time, and ways in which injury may be reduced and the cochlea protected during middle ear surgery.

  11. Broad-Band Visually Evoked Potentials: Re(convolution in Brain-Computer Interfacing.

    Directory of Open Access Journals (Sweden)

    Jordy Thielen

    Full Text Available Brain-Computer Interfaces (BCIs allow users to control devices and communicate by using brain activity only. BCIs based on broad-band visual stimulation can outperform BCIs using other stimulation paradigms. Visual stimulation with pseudo-random bit-sequences evokes specific Broad-Band Visually Evoked Potentials (BBVEPs that can be reliably used in BCI for high-speed communication in speller applications. In this study, we report a novel paradigm for a BBVEP-based BCI that utilizes a generative framework to predict responses to broad-band stimulation sequences. In this study we designed a BBVEP-based BCI using modulated Gold codes to mark cells in a visual speller BCI. We defined a linear generative model that decomposes full responses into overlapping single-flash responses. These single-flash responses are used to predict responses to novel stimulation sequences, which in turn serve as templates for classification. The linear generative model explains on average 50% and up to 66% of the variance of responses to both seen and unseen sequences. In an online experiment, 12 participants tested a 6 × 6 matrix speller BCI. On average, an online accuracy of 86% was reached with trial lengths of 3.21 seconds. This corresponds to an Information Transfer Rate of 48 bits per minute (approximately 9 symbols per minute. This study indicates the potential to model and predict responses to broad-band st