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Sample records for evoked responses constrained

  1. BAER - brainstem auditory evoked response

    Science.gov (United States)

    ... auditory potentials; Brainstem auditory evoked potentials; Evoked response audiometry; Auditory brainstem response; ABR; BAEP ... Normal results vary. Results will depend on the person and the instruments used to perform the test.

  2. Somatosensory evoked response: application in neurology

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    Carlos A. M. Guerreiro

    1982-03-01

    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

    2014-01-01

    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.

    1999-04-01

    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. Intraurethral stimulation evokes bladder responses via 2 distinct reflex pathways.

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    Woock, John P; Yoo, Paul B; Grill, Warren M

    2009-07-01

    Recent animal studies have shown that selective activation of pudendal nerve branches can evoke bladder responses through 2 distinct reflex pathways. We examined intraurethral electrical stimulation as a minimally invasive means of selectively activating these pathways in the cat. Bladder responses evoked by intraurethral electrical stimulation were measured in alpha-chloralose anesthetized male cats at different stimulation frequencies, stimulation intensities and intraurethral locations. Intraurethral electrical stimulation evoked inhibitory and excitatory bladder reflexes depending on stimulation frequency and location. Stimulation in the penile urethra 0 to 3 cm from the urethral meatus at 33 Hz evoked bladder contraction and at 10 Hz it evoked bladder relaxation. These responses were abolished after bilateral transection of the dorsal penile nerves. Stimulation in the membranous urethra 5 to 7 cm from the urethral meatus at 2, 10 and 33 Hz evoked bladder contractions. These responses were abolished after bilateral transection of the cranial sensory nerves. Following acute spinal cord transection bladder contractions were still evoked by 33 Hz stimulation in the penile urethra but not by stimulation at any frequency in the membranous urethra. Intraurethral electrical stimulation selectively evoked bladder responses by activating 2 distinct pudendal afferent pathways. Responses depended on stimulation frequency and location. Intraurethral electrical stimulation is a valid means of determining the pathways involved in bladder responses evoked by pudendal nerve stimulation.

  6. Evoked responses to sinusoidally modulated sound in unanaesthetized dogs

    NARCIS (Netherlands)

    Tielen, A.M.; Kamp, A.; Lopes da Silva, F.H.; Reneau, J.P.; Storm van Leeuwen, W.

    1. 1. Responses evoked by sinusoidally amplitude-modulated sound in unanaesthetized dogs have been recorded from inferior colliculus and from auditory cortex structures by means of chronically indwelling stainless steel wire electrodes. 2. 2. Harmonic analysis of the average responses demonstrated

  7. Pattern visual evoked responses in hereditary spastic paraplegia

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    Livingstone, I R; Mastaglia, F L; Edis, R; Howe, J W

    1981-01-01

    Pattern visual evoked responses were studied in 13 patients from nine families with dominant herditary spastic paraplegia and in seven sporadic cases. The responses were normal in all the dominantly inherited cases but abnormal in three of the seven sporadic cases. PMID:7217977

  8. Visual evoked responses during standing and walking

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    Klaus Gramann

    2010-10-01

    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.

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

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

    1980-01-01

    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)

  10. Brain stem auditory evoked responses in human infants and adults

    Science.gov (United States)

    Hecox, K.; Galambos, R.

    1974-01-01

    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.

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

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    J. Tillein

    2012-01-01

    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.

  12. Click-evoked responses in vestibular afferents in rats

    National Research Council Canada - National Science Library

    Zhu, Hong; Tang, Xuehui; Wei, Wei; Mustain, William; Xu, Youguo; Zhou, Wu

    2011-01-01

    Sound activates not only the cochlea but also the vestibular end organs. Research on this phenomenon led to the discovery of the sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles...

  13. Brain stem evoked response audiometry of former drug users.

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    Weich, Tainara Milbradt; Tochetto, Tania Maria; Seligman, Lilian

    2012-10-01

    Illicit drugs are known for their deleterious effects upon the central nervous system and more specifically for how they adversely affect hearing. 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. 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 drugs: 1 to 5 years, 6 to 10 years, and over 15 years. They were interviewed, and assessed by pure tone audiometry, acoustic impedance tests, and BERA. No statistically significant differences were found between G1 and G2 or time of drug use in absolute latencies and interpeak intervals. However, only five of the 17 individuals had BERA results with adequate results for their ages. Marijuana and crack/cocaine may cause diffuse disorders in the brainstem and compromise the transmission of auditory stimuli regardless of how long these substances are used for.

  14. Analysis of visual evoked responses in multiple sclerosis.

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    Mallecourt, J; Chain, F; Leblanc, M; Lhermitte, F

    1980-12-01

    In Multiple Sclerosis (MS) the modification of the latency of visual evoked responses (VER's) shows sequels of the involvement of anterior optic tracts manifested by a retro-bulbar optic neuritis (RBON). This study was made on 102 patients with MS. The stimulus used the pattern reversal of a checkboard. The influence of the size and squares 8' and 20' chosen as stimulus has been first studied in patients with antecedents of RBON. Using the 8' squares, all eyes with a history of RBON had pathological VER's. When there is no clinical antecedent of RBON, this means of stimulation enabled us to detect sequels of RBON. In "definitive" and "probable" MS, 100% of patients had pathological VER's either for both eyes of a single eyes. In "possible" MS a sequel of RBON was demonstrated in 57% of this population without clinical antecedent of RBON. A correlation between VER's result and the ophthalmological examination (visual acuity, fundoscopic examination and acquired dyschromatopsie) was made. Although VER's are an excellent method for detecting the sequels of RBON in MS. VER's abnormalities have no etiological significance, they are observed in other neurological involvements of anterior optic tracts. These different points are discussed and a physiological interpretation of VER's abnormalities is proposed.

  15. Temporal Tuning Effects in the Visually Evoked Response,

    Science.gov (United States)

    1985-08-01

    Berger (1932) also observed that these brain waves are slowed in states of depressed function such as sleep activity and that they can be blocked by...Ma4cay and Jefferys, 1973). Transient VER’s, polyphasic in form and 200-500 milliseconds in duration, are evoked by stepwise changes in one or more per

  16. Dynamic causal modeling of evoked responses in EEG and MEG.

    Science.gov (United States)

    David, Olivier; Kiebel, Stefan J; Harrison, Lee M; Mattout, Jérémie; Kilner, James M; Friston, Karl J

    2006-05-01

    Neuronally plausible, generative or forward models are essential for understanding how event-related fields (ERFs) and potentials (ERPs) are generated. In this paper, we present a new approach to modeling event-related responses measured with EEG or MEG. This approach uses a biologically informed model to make inferences about the underlying neuronal networks generating responses. The approach can be regarded as a neurobiologically constrained source reconstruction scheme, in which the parameters of the reconstruction have an explicit neuronal interpretation. Specifically, these parameters encode, among other things, the coupling among sources and how that coupling depends upon stimulus attributes or experimental context. The basic idea is to supplement conventional electromagnetic forward models, of how sources are expressed in measurement space, with a model of how source activity is generated by neuronal dynamics. A single inversion of this extended forward model enables inference about both the spatial deployment of sources and the underlying neuronal architecture generating them. Critically, this inference covers long-range connections among well-defined neuronal subpopulations. In a previous paper, we simulated ERPs using a hierarchical neural-mass model that embodied bottom-up, top-down and lateral connections among remote regions. In this paper, we describe a Bayesian procedure to estimate the parameters of this model using empirical data. We demonstrate this procedure by characterizing the role of changes in cortico-cortical coupling, in the genesis of ERPs. In the first experiment, ERPs recorded during the perception of faces and houses were modeled as distinct cortical sources in the ventral visual pathway. Category-selectivity, as indexed by the face-selective N170, could be explained by category-specific differences in forward connections from sensory to higher areas in the ventral stream. We were able to quantify and make inferences about these

  17. Electrically-evoked frequency-following response (EFFR) in the auditory brainstem of guinea pigs.

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    He, Wenxin; Ding, Xiuyong; Zhang, Ruxiang; Chen, Jing; Zhang, Daoxing; Wu, Xihong

    2014-01-01

    It is still a difficult clinical issue to decide whether a patient is a suitable candidate for a cochlear implant and to plan postoperative rehabilitation, especially for some special cases, such as auditory neuropathy. A partial solution to these problems is to preoperatively evaluate the functional integrity of the auditory neural pathways. For evaluating the strength of phase-locking of auditory neurons, which was not reflected in previous methods using electrically evoked auditory brainstem response (EABR), a new method for recording phase-locking related auditory responses to electrical stimulation, called the electrically evoked frequency-following response (EFFR), was developed and evaluated using guinea pigs. The main objective was to assess feasibility of the method by testing whether the recorded signals reflected auditory neural responses or artifacts. The results showed the following: 1) the recorded signals were evoked by neuron responses rather than by artifact; 2) responses evoked by periodic signals were significantly higher than those evoked by the white noise; 3) the latency of the responses fell in the expected range; 4) the responses decreased significantly after death of the guinea pigs; and 5) the responses decreased significantly when the animal was replaced by an electrical resistance. All of these results suggest the method was valid. Recording obtained using complex tones with a missing fundamental component and using pure tones with various frequencies were consistent with those obtained using acoustic stimulation in previous studies.

  18. Auditory evoked responses upon awakening from sleep in human subjects.

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    Ferrara, M; De Gennaro, L; Ferlazzo, F; Curcio, G; Barattucci, M; Bertini, M

    2001-09-14

    The hypothesis that a state of hypoarousal upon awakening should lead to a decrease in amplitude and an increase in latency of the N1-P2 components of the Auditory Evoked Potentials (AEPs) as compared to presleep wakefulness levels, was evaluated after two nocturnal awakenings and after the final morning awakening from a 7.5-h night of sleep. The amplitude of the N1-P2 complex was reduced upon awakening as compared to presleep wakefulness levels, but only following the first nocturnal awakening, scheduled after the first 2 h of sleep. This result is interpreted as indicating a link between slow wave sleep amount, mainly present during the first part of the night, and lowered levels of brain activation upon awakening. The reaction times, recorded concomitantly to AEPs, were more sensitive to the negative effects of sleep inertia.

  19. Evoked response audiometry in scrub typhus: prospective, randomised, case-control study.

    Science.gov (United States)

    Thakur, J S; Mohindroo, N K; Sharma, D R; Soni, K; Kaushal, S S

    2011-06-01

    To investigate the hypothesis of cochlear and retrocochlear damage in scrub typhus, using evoked response audiometry. Prospective, randomised, case-control study. The study included 25 patients with scrub typhus and 25 controls with other febrile illnesses not known to cause hearing loss. Controls were age- and sex-matched. All subjects underwent pure tone audiometry and evoked response audiometry before commencing treatment. Six patients presented with hearing loss, although a total of 23 patients had evidence of symmetrical high frequency loss on pure tone audiometry. Evoked response audiometry found significant prolongation of absolute latencies of wave I, III, V, and wave I-III interpeak latency. Two cases with normal hearing had increased interpeak latencies. These findings constitute level 3b evidence. Findings were suggestive of retrocochlear pathology in two cases with normal hearing. In other patients, high frequency hearing loss may have led to altered evoked response results. Although scrub typhus appears to cause middle ear cochlear and retrocochlear damage, the presence of such damage could not be fully confirmed by evoked response audiometry.

  20. Responses evoked by a vestibular implant providing chronic stimulation.

    Science.gov (United States)

    Thompson, Lara A; Haburcakova, Csilla; Gong, Wangsong; Lee, Daniel J; Wall, Conrad; Merfeld, Daniel M; Lewis, Richard F

    2012-01-01

    Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly integrative behaviors, such as the perception of head orientation and posture have remained unclear. We tested a one-dimensional, unilateral prosthesis in a rhesus monkey with bilateral vestibular loss and found that chronic electrical stimulation partially restored the compensatory VOR and also that percepts of head orientation relative to gravity were improved. However, the one-dimensional prosthetic stimulation had no clear effect on postural stability during quiet stance, but sway evoked by head-turns was modestly reduced. These results suggest that not only can the implementation of a vestibular prosthesis provide partial restitution of VOR but may also improve perception and posture in the presence of bilateral vestibular hypofunction (BVH). In this review, we provide an overview of our previous and current work directed towards the eventual clinical implementation of an implantable vestibular prosthesis.

  1. Altered Evoked Gamma-Band Responses Reveal Impaired Early Visual Processing in ADHD Children

    Science.gov (United States)

    Lenz, Daniel; Krauel, Kerstin; Flechtner, Hans-Henning; Schadow, Jeanette; Hinrichs, Hermann; Herrmann, Christoph S.

    2010-01-01

    Neurophysiological studies yield contrary results whether attentional problems of patients with attention-deficit/hyperactivity disorder (ADHD) are related to early visual processing deficits or not. Evoked gamma-band responses (GBRs), being among the first cortical responses occurring as early as 90 ms after visual stimulation in human EEG, have…

  2. Speech-evoked auditory brainstem responses in children with hearing loss.

    Science.gov (United States)

    Koravand, Amineh; Al Osman, Rida; Rivest, Véronique; Poulin, Catherine

    2017-08-01

    The main objective of the present study was to investigate subcortical auditory processing in children with sensorineural hearing loss. Auditory Brainstem Responses (ABRs) were recorded using click and speech/da/stimuli. Twenty-five children, aged 6-14 years old, participated in the study: 13 with normal hearing acuity and 12 with sensorineural hearing loss. No significant differences were observed for the click-evoked ABRs between normal hearing and hearing-impaired groups. For the speech-evoked ABRs, no significant differences were found for the latencies of the following responses between the two groups: onset (V and A), transition (C), one of the steady-state wave (F), and offset (O). However, the latency of the steady-state waves (D and E) was significantly longer for the hearing-impaired compared to the normal hearing group. Furthermore, the amplitude of the offset wave O and of the envelope frequency response (EFR) of the speech-evoked ABRs was significantly larger for the hearing-impaired compared to the normal hearing group. Results obtained from the speech-evoked ABRs suggest that children with a mild to moderately-severe sensorineural hearing loss have a specific pattern of subcortical auditory processing. Our results show differences for the speech-evoked ABRs in normal hearing children compared to hearing-impaired children. These results add to the body of the literature on how children with hearing loss process speech at the brainstem level. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A translational study on looming-evoked defensive response and the underlying subcortical pathway in autism.

    Science.gov (United States)

    Hu, Yu; Chen, Zhuoming; Huang, Lu; Xi, Yue; Li, Bingxiao; Wang, Hong; Yan, Jiajian; Lee, Tatia M C; Tao, Qian; So, Kwok-Fai; Ren, Chaoran

    2017-11-07

    Rapidly approaching objects indicating threats can induce defensive response through activating a subcortical pathway comprising superior colliculus (SC), lateral posterior nucleus (LP), and basolateral amygdala (BLA). Abnormal defensive response has been reported in autism, and impaired synaptic connections could be the underlying mechanism. Whether the SC-LP-BLA pathway processes looming stimuli abnormally in autism is not clear. Here, we found that looming-evoked defensive response is impaired in a subgroup of the valproic acid (VPA) mouse model of autism. By combining the conventional neurotracer and transneuronal rabies virus tracing techniques, we demonstrated that synaptic connections in the SC-LP-BLA pathway were abnormal in VPA mice whose looming-evoked defensive responses were absent. Importantly, we further translated the finding to children with autism and observed that they did not present looming-evoked defensive response. Furthermore, the findings of the DTI with the probabilistic tractography showed that the structural connections of SC-pulvinar-amygdala in autism children were weak. The pulvinar is parallel to the LP in a mouse. Because looming-evoked defensive response is innate in humans and emerges much earlier than do social and language functions, the absence of defensive response could be an earlier sign of autism in children.

  4. Cortical Auditory-Evoked Responses in Preterm Neonates: Revisited by Spectral and Temporal Analyses.

    Science.gov (United States)

    Kaminska, A; Delattre, V; Laschet, J; Dubois, J; Labidurie, M; Duval, A; Manresa, A; Magny, J-F; Hovhannisyan, S; Mokhtari, M; Ouss, L; Boissel, A; Hertz-Pannier, L; Sintsov, M; Minlebaev, M; Khazipov, R; Chiron, C

    2017-08-11

    Characteristic preterm EEG patterns of "Delta-brushes" (DBs) have been reported in the temporal cortex following auditory stimuli, but their spatio-temporal dynamics remains elusive. Using 32-electrode EEG recordings and co-registration of electrodes' position to 3D-MRI of age-matched neonates, we explored the cortical auditory-evoked responses (AERs) after 'click' stimuli in 30 healthy neonates aged 30-38 post-menstrual weeks (PMW). (1) We visually identified auditory-evoked DBs within AERs in all the babies between 30 and 33 PMW and a decreasing response rate afterwards. (2) The AERs showed an increase in EEG power from delta to gamma frequency bands over the middle and posterior temporal regions with higher values in quiet sleep and on the right. (3) Time-frequency and averaging analyses showed that the delta component of DBs, which negatively peaked around 550 and 750 ms over the middle and posterior temporal regions, respectively, was superimposed with fast (alpha-gamma) oscillations and corresponded to the late part of the cortical auditory-evoked potential (CAEP), a feature missed when using classical CAEP processing. As evoked DBs rate and AERs delta to alpha frequency power decreased until full term, auditory-evoked DBs are thus associated with the prenatal development of auditory processing and may suggest an early emerging hemispheric specialization. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Brainstem auditory evoked responses in 37 dogs with otitis media before and after topical therapy.

    Science.gov (United States)

    Paterson, S

    2017-07-18

    The objective of this study was to determine whether intra-aural administration of aqueous solutions of marbofloxacin, gentamicin, tobramycin and ticarcillin (used off-licence) was associated with changes in hearing as measured by brainstem auditory evoked responses. Dogs diagnosed with otitis media (n=37) underwent brainstem auditory evoked response testing and then were treated for their ear disease. First, the external ear canal and middle ear were flushed with sterile saline followed by EDTA tris with 0·15% chlorhexidine. Then, a combination of aqueous antibiotic mixed with an aqueous solution of EDTA tris was instilled into the middle ear. Follow-up examinations were undertaken for each dog, and treatment was continued until there were no detected infectious organisms or inflammatory infiltrate. Brainstem auditory evoked response testing was repeated after resolution of the infection and discontinuation of therapy. Brainstem auditory evoked responses in dogs treated with aqueous solutions of marbofloxacin or gentamicin remained unchanged or improved after therapy of otitis media but were impaired in dogs treated with ticarcillin or tobramycin. If off-licence use of topical antibiotics is deemed necessary in cases of otitis media, aqueous solutions of marbofloxacin and gentamicin appear to be less ototoxic than aqueous solutions of ticarcillin or tobramycin. © 2017 British Small Animal Veterinary Association.

  6. Long-term moderate exercise accelerates the recovery of stress-evoked cardiovascular responses.

    Science.gov (United States)

    Hsu, Yuan-Chang; Tsai, Sheng-Feng; Yu, Lung; Chuang, Jih-Ing; Wu, Fong-Sen; Jen, Chauying J; Kuo, Yu-Min

    2016-01-01

    Psychological stress is an important global health problem. It is well documented that stress increases the incidences of various cardiovascular disorders. Regular exercise is known to reduce resting blood pressure (BP) and heart rate (HR). This study was designed to clarify the effects of long-term exercise on stress-evoked cardiovascular responses and to emphasize post-stress recovery effects. Male Wistar rats underwent 8 weeks of moderate treadmill training, with cardiovascular responses, autonomic nervous system activities and local Fos reactivity changes in the cardiovascular regulation center were monitored before, during and after immobilization stress. A spectral analysis of cardiovascular parameters was used to examine autonomic nervous activities. We found that long-term exercise (i) lowered resting BP, HR and sympathetic activity, but increased resting parasympathetic activity and baroreflex sensitivity (BRS); (ii) accelerated post-stress recovery of stress-evoked cardiovascular and sympathetic responses along with increased BRS and (iii) accelerated post-stress recovery of stress-evoked neuron activations in the paraventricular nucleus, but delayed it in the nucleus of the tractus solitarius. We conclude that, in rats, long-term exercise accelerated recovery of stress-evoked cardiovascular responses differentially altering hypothalamic and medullar neuron activities.

  7. Regularity increases middle latency evoked and late induced beta brain response following proprioceptive stimulation

    DEFF Research Database (Denmark)

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

    2008-01-01

    as an indication of increased readiness. This is achieved through detailed analysis of both evoked and induced responses in the time-frequency domain. Electroencephalography in a 64 channels montage was recorded in four-teen healthy subjects. Two paradigms were explored: A Regular alternation between hand...

  8. Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle

    OpenAIRE

    Mang, Daniel WH; Siegmund, Gunter P.; Blouin, Jean-Sébastien

    2014-01-01

    Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending pattern of muscle recruitment and changes in autonomic activity. Here we examined the recruitment of ...

  9. Modeling auditory evoked brainstem responses to transient stimuli

    DEFF Research Database (Denmark)

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

    2012-01-01

    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. Fluorescent tube light evokes flicker responses in visual neurons.

    Science.gov (United States)

    Eysel, U T; Burandt, U

    1984-01-01

    Single neurons in the cat visual system respond distinctly to the temporal information present in light from fluorescent tubes driven by 50 or 60 Hz alternating current. Despite the resulting flicker frequencies of 100 or 120 Hz all retinal and most thalamic neurons show strong phase locking of the neuronal responses to the modulation of fluorescent tube light. Some retinal ganglion cells have not yet reached their critical flicker fusion frequency under such conditions. Though usually beyond perception, the frequency and depth of modulation of artificial light thus might well play a role in biological light effects.

  11. Normal Evoked Response to Rapid Sequences of Tactile Pulses in Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Santosh Ganesan

    2016-09-01

    Full Text Available Autism spectrum disorder (ASD is a developmental disorder diagnosed behaviorally, with many documented neurophysiological abnormalities in cortical response properties. While abnormal sensory processing is not considered core to the disorder, most ASD individuals report sensory processing abnormalities. Yet, the neurophysiological correlates of these abnormalities have not been fully mapped. In the auditory domain, studies have shown that cortical responses in the early auditory cortex in ASD are abnormal in multiple ways. In particular, it has been shown that individuals with ASD who were also language impaired, have abnormal cortical auditory evoked responses to rapid, but not slow, sequences of tones. Here, we tested the somatosensory domain in ASD for abnormalities in rapid processing of tactile pulses, to determine whether abnormalities there parallel those observed in the auditory domain. Specifically, we tested the somatosensory cortex response to a sequence of two tactile pulses with different (short and long temporal separation. We analyzed the responses in cortical space, in primary somatosensory cortex. As expected, we found no group difference in the evoked response to pulses with long temporal separation. Contrary to findings in the auditory domain and to our hypothesis, we also found no group differences in the evoked responses to the sequence with a short temporal separation. These results suggest that rapid temporal processing deficits in ASD are not generalized across multiple sensory domains, and are unlikely to underlie the behavioral somatosensory abnormalities observed in ASD.

  12. Endogenous Opioid Function Mediates the Association Between Laboratory Evoked Pain Sensitivity and Morphine Analgesic Responses

    Science.gov (United States)

    Bruehl, Stephen; Burns, John W.; Gupta, Rajnish; Buvanendran, Asokumar; Chont, Melissa; Kinner, Ellen; Schuster, Erik; Passik, Steven; France, Christopher R.

    2014-01-01

    Predictors of responsiveness to opioid analgesic medications are not well understood. This study tested whether individual differences in endogenous opioid (EO) function are associated with analgesic responsiveness to morphine. In randomized, counterbalanced order over three sessions, 45 chronic low back pain participants (CLBP) and 31 healthy controls received an opioid antagonist (8mg naloxone), morphine (0.08 mg/kg), or placebo. Participants then engaged in two laboratory evoked pain tasks (ischemic, thermal). Outcomes included pain threshold, pain tolerance, and pain ratings. Indexes of EO function and morphine analgesic responsiveness were derived for each measure as the difference in pain responses between the placebo condition, and naloxone or morphine conditions respectively. For all 7 pain measures across the two laboratory pain tasks, greater EO function was associated with significantly lower morphine analgesic responsiveness (p ≤ .001 − p=.02). Morphine reduced pain responses of low EO individuals to levels similar to high EO individuals under placebo. Higher placebo condition evoked pain sensitivity was associated with significantly greater morphine analgesic responsiveness for 5 of 7 pain measures (p<.001 − p=.02). These latter associations were significantly mediated by EO function for 4 of these 5 pain outcomes (p’s<.05). In the laboratory evoked pain context, opioid analgesic medications may supplement inadequate EO analgesia, with little incremental benefit in those with pre-existing high EO function. Implications for personalized medicine are discussed. PMID:23748117

  13. Purinoceptors Evoke Different Electrophysiological Responses in Pancreatic Ducts

    DEFF Research Database (Denmark)

    Hede, S E; Amstrup, Jan; Christoffersen, Bettina C

    1999-01-01

    , intracellular Ca(2+) and pH measurements, and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The data show two types of purinoceptors and cellular responses. UTP and ATP produced large Ca(2+) transients, a decrease in intracellular pH, 8-10-mV depolarization of the membrane voltage......, 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......-benzoylbenzoyl-ATP induced Ca(2+) influx and approximately 20-mV depolarization of the membrane voltage with a concomitant increase in the whole-cell conductance. These effects were dependent on extracellular Na(+), not Cl(-), indicating opening of cation channels associated with P2X(7) purinoceptors. RT...

  14. Objective information-theoretic algorithm for detecting brainstem-evoked responses to complex stimuli.

    Science.gov (United States)

    Bidelman, Gavin M

    2014-09-01

    The scalp-recorded frequency-following response (FFR), an auditory-evoked potential with putative neural generators in the rostral brainstem, provides a robust representation of the neurophysiologic encoding of complex stimuli. The FFR is rapidly becoming a valuable tool for understanding the neural transcription of speech and music, language-related processing disorders, and brain plasticity at initial stages of the auditory pathway. Despite its potential clinical and empirical utility, determining the presence of a response is still dependent on the subjective interpretation by an experimenter/clinician. The purpose of the present work was to develop and validate a fully objective procedure for the automatic detection of FFRs elicited by complex auditory stimuli, including speech. Mutual information (MI) was computed between the spectrographic representation of neural FFRs and their evoking acoustic stimuli to quantify the amount of shared time-frequency information between electrophysiologic responses and stimulus acoustics. To remove human subjectivity associated with typical response evaluation, FFRs were first simulated at known signal-to-noise ratios using a computational model of the auditory periphery. The MI at which model FFRs contained +3 dB Signal-to-noise ratio was taken as the criterion threshold (θMI) for the presence of a response. θMI was then applied as a binary classifier on actual neurophysiologic responses recorded previously in human participants (n = 35). Sham recordings, in which no stimulus was presented to participants, allowed us to determine the receiver operating characteristics of the MI metric and the capabilities of the algorithm to segregate true evoked responses from sham recordings. RESULTS showed high overall accuracy (93%) in the metric's ability to identify true responses from sham recordings. The metric's overall performance was considerably better than trained human observers who, on average, accurately identified only

  15. Visually-evoked pattern and photomyoclonic responses in video game and television epilepsy: case reports.

    Science.gov (United States)

    Anyanwu, E; Watson, N A

    1996-01-01

    This research paper reports a case study of two male photosensitive epileptic patients, aged 14 and 16 years old respectively, whose epileptic seizures were often triggered by the flickers from television and video games respectively. The 14-year old patient had no family history of epilepsy, while the 16 year old had a family history of epilepsy. A comprehensive electroencephalogram (EEG), including hyperventilation, intermittent photic stimulation (IPS) and pattern stimulation were carried out on them and EEG abnormalities including photoparoxysmal responses (PPR) and generalized myoclonic responses were evoked. A thorough analysis of the EEG morphology of the myclonic responses and the clinical manifestations showed evidence of two separate entitles of seizures namely: visually evoked pattern-myoclonic responses (PTMR) and visually evoked photomyoclonic responses (PMR). PTMR was independent of flash rate and occurred before a PPR and at the same time as the flash rate, while PMR occurred after the PPR and was dependent on flash rate. These findings suggest that "Video Game" epilepsy is probably a pattern sensitive epilepsy, electronic screen being the source of the triggering patterns; hence, the morphology and the family histories and the myoclonic phenomena differ from those of pure photosensitive epilepsy.

  16. A comparison of myogenic motor evoked responses to electrical and magnetic transcranial stimulation during nitrous oxide/opioid anesthesia

    NARCIS (Netherlands)

    Ubags, L. H.; Kalkman, C. J.; Been, H. D.; Koelman, J. H.; Ongerboer de Visser, B. W.

    1999-01-01

    Transcranial motor evoked potentials (tc-MEPs) are used to monitor spinal cord integrity intraoperatively. We compared myogenic motor evoked responses with electrical and magnetic transcranial stimuli during nitrous oxide/opioid anesthesia. In 11 patients undergoing spinal surgery, anesthesia was

  17. TRPV4 channels mediate the infrared laser-evoked response in sensory neurons.

    Science.gov (United States)

    Albert, E S; Bec, J M; Desmadryl, G; Chekroud, K; Travo, C; Gaboyard, S; Bardin, F; Marc, I; Dumas, M; Lenaers, G; Hamel, C; Muller, A; Chabbert, C

    2012-06-01

    Infrared laser irradiation has been established as an appropriate stimulus for primary sensory neurons under conditions where sensory receptor cells are impaired or lost. Yet, development of clinical applications has been impeded by lack of information about the molecular mechanisms underlying the laser-induced neural response. Here, we directly address this question through pharmacological characterization of the biological response evoked by midinfrared irradiation of isolated retinal and vestibular ganglion cells from rodents. Whole cell patch-clamp recordings reveal that both voltage-gated calcium and sodium channels contribute to the laser-evoked neuronal voltage variations (LEVV). In addition, selective blockade of the LEVV by micromolar concentrations of ruthenium red and RN 1734 identifies thermosensitive transient receptor potential vanilloid channels as the primary effectors of the chain reaction triggered by midinfrared laser irradiation. These results have the potential to facilitate greatly the design of future prosthetic devices aimed at restoring neurosensory capacities in disabled patients.

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

    Directory of Open Access Journals (Sweden)

    Kelly eTremblay

    2014-02-01

    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

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

    Science.gov (United States)

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

    2014-01-01

    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

  20. Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle.

    Science.gov (United States)

    Mang, Daniel Wh; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2014-06-01

    Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending pattern of muscle recruitment and changes in autonomic activity. Here we examined the recruitment of axial and appendicular muscles along with autonomic responses to confirm whether these other features of a startle response were present during the first exposure to a whiplash perturbation. Ten subjects experienced a single whiplash perturbation while recording electromyography, electrocardiogram, and electrodermal responses. All subjects exhibited a descending pattern of muscle recruitment, and increasing heart rate and electrodermal responses following the collision. Our results provide further support that the startle response is a component of the response to whiplash collisions.

  1. Differential effects of LSD serotonin and l-tryptophan on visually evoked responses.

    Science.gov (United States)

    Strahlendorf, J C; Goldstein, F J; Rossi, G V; Malseed, R T

    1982-01-01

    Alterations in photically-evoked cortical responses were assessed in immobilized artificially respired cats following intraraphe microinjections of LSD and serotonin (5-HT) and IV administration of LSD and l-tryptophan. Both systemic (10-100 micrograms/kg; N = 5) and intraraphe (0.25 microgram; N = 10) LSD significantly increased the amplitudes of the three primary components of the visual evoked response (VER). In contrast, the same VER components were significantly depressed following intraraphe 5-HT (30 micrograms; N = 4) and IV l-tryptophan (100 mg/kg; N = 6), a serotonin precursor that elevates raphe 5-HT levels. Intraraphe cinanserin (180 micrograms; 30 minute pretreatment) completely reversed LSD-induced enhancements in all three components (p less than 0.01). Depressions of VER following intraraphe 5-HT (30 micrograms) were also antagonized by cinanserin, although to lesser degree (p less than 0.05 for first 2 components only) than with LSD. The depressive effects of l-tryptophan (100 mg/kg) were unaffected by cinanserin. Modification of raphe neuronal activity can significantly alter photically evoked responses, and may explain the perceptual disturbances associated with LSD, i.e., depression of an area (raphe) normally inhibiting forebrain areas of the visual system.

  2. Brainstem auditory evoked responses in man. 1: Effect of stimulus rise-fall time and duration

    Science.gov (United States)

    Hecox, K.; Squires, N.; Galambos, R.

    1975-01-01

    Short latency (under 10 msec) responses elicited by bursts of white noise were recorded from the scalps of human subjects. Response alterations produced by changes in the noise burst duration (on-time), inter-burst interval (off-time), and onset and offset shapes were analyzed. The latency of the most prominent response component, wave V, was markedly delayed with increases in stimulus rise time but was unaffected by changes in fall time. Increases in stimulus duration, and therefore in loudness, resulted in a systematic increase in latency. This was probably due to response recovery processes, since the effect was eliminated with increases in stimulus off-time. The amplitude of wave V was insensitive to changes in signal rise and fall times, while increasing signal on-time produced smaller amplitude responses only for sufficiently short off-times. It was concluded that wave V of the human auditory brainstem evoked response is solely an onset response.

  3. Comparison of binaural auditory brainstem responses and the binaural difference potential evoked by chirps and clicks.

    Science.gov (United States)

    Riedel, Helmut; Kollmeier, Birger

    2002-07-01

    Rising chirps that compensate for the dispersion of the travelling wave on the basilar membrane evoke larger monaural brainstem responses than clicks. In order to test if a similar effect applies for the early processing stages of binaural information, monaurally and binaurally evoked auditory brainstem responses were recorded for clicks and chirps for levels from 10 to 60 dB nHL in steps of 10 dB. Ten thousand sweeps were collected for every stimulus condition from 10 normal hearing subjects. Wave V amplitudes are significantly larger for chirps than for clicks for all conditions. The amplitude of the binaural difference potential, DP1-DN1, is significantly larger for chirps at the levels 30 and 40 dB nHL. Both the binaurally evoked potential and the binaural difference potential exhibit steeper growth functions for chirps than for clicks for levels up to 40 dB nHL. For higher stimulation levels the chirp responses saturate approaching the click evoked amplitude. For both stimuli the latency of DP1 is shorter than the latency of the binaural wave V, which in turn is shorter than the latency of DN1. The amplitude ratio of the binaural difference potential to the binaural response is independent of stimulus level for clicks and chirps. A possible interpretation is that with click stimulation predominantly binaural interaction from high frequency regions is seen which is compatible with a processing by contralateral inhibitory and ipsilateral excitatory (IE) cells. Contributions from low frequencies are negligible since the responses from low frequencies are not synchronized for clicks. The improved synchronization at lower frequencies using chirp stimuli yields contributions from both low and high frequency neurons enlarging the amplitudes of the binaural responses as well as the binaural difference potential. Since the constant amplitude ratio of the binaural difference potential to the binaural response makes contralateral and ipsilateral excitatory interaction

  4. Speech-evoked cortical auditory responses in children with normal hearing

    Directory of Open Access Journals (Sweden)

    Aseel Almeqbel

    2013-12-01

    Full Text Available Objective: Cortical auditory-evoked potentials (CAEPs, an objective measure of human speech encoding in individuals with normal or impaired auditory systems, can be used to assess the outcomes of hearing aids and cochlear implants in infants, or in young children who cannot co-operate for behavioural speech discrimination testing. The current study aimed to determine whether naturally produced speech stimuli /m/, /g/ and /t/ evoke distinct CAEP response patterns that can be reliably recorded and differentiated, based on their spectral information and whether the CAEP could be an electrophysiological measure to differentiate between these speech sounds.Method: CAEPs were recorded from 18 school-aged children with normal hearing, tested in two groups: younger (5 - 7 years and older children (8 - 12 years. Cortical responses differed in their P1 and N2 latencies and amplitudes in response to /m/, /g/ and /t/ sounds (from low-, mid- and high-frequency regions, respectively. The largest amplitude of the P1 and N2 component was for /g/ and the smallest was for /t/. The P1 latency in both age groups did not show any significant difference between these speech sounds. The N2 latency showed a significant change in the younger group but not in the older group. The N2 latency of the speech sound /g/ was always noted earlier in both groups.Conclusion: This study demonstrates that spectrally different speech sounds are encoded differentially at the cortical level, and evoke distinct CAEP response patterns. CAEP latencies and amplitudes may provide an objective indication that spectrally different speech sounds are encoded differently at the cortical level.

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

    Directory of Open Access Journals (Sweden)

    Marat eMinlebaev

    2013-05-01

    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. The investigation of cortical auditory evoked potentials responses in young adults having musical education.

    Science.gov (United States)

    Polat, Zahra; Ataş, Ahmet

    2014-12-01

    In the literature, music education has been shown to enhance auditory perception for children and young adults. When compared to young adult non-musicians, young adult musicians demonstrate increased auditory processing, and enhanced sensitivity to acoustic changes. The evoked response potentials associated with the interpretation of sound are enhanced in musicians. Studies show that training also changes sound perception and cortical responses. The earlier training appears to lead to larger changes in the auditory cortex. Most cortical studies in the literature have used pure tones or musical instrument sounds as stimuli signals. The aim of those studies was to investigate whether musical education would enhance auditory cortical responses when speech signals were used. In this study, the speech sounds extracted from running speech were used as sound stimuli. Non-randomized controlled study. The experimental group consists of young adults up to 21 years-old, all with a minimum of 4 years of musical education. The control group was selected from young adults of the same age without any musical education. The experiments were conducted by using a cortical evoked potential analyser and /m/, /t/ /g/ sound stimulation at the level of 65 dB SPL. In this study, P1 / N1 / P2 amplitude and latency values were measured. Significant differences were found in the amplitude values of P1 and P2 (p0.05). The results obtained in our study indicate that musical experience has an effect on the nervous system and this can be seen in cortical auditory evoked potentials recorded when the subjects hear speech.

  7. Brain stem evoked response to forward and reversed speech in humans.

    Science.gov (United States)

    Galbraith, Gary C; Amaya, Elizabeth M; de Rivera, Jacinta M Diaz; Donan, Namee M; Duong, Mylien T; Hsu, Jeffrey N; Tran, Kim; Tsang, Lian P

    2004-09-15

    Speech stimuli played in reverse are perceived as unfamiliar and alien-sounding, even though phoneme duration and fundamental voicing frequency are preserved. Although language perception ultimately resides in the neocortex, the brain stem plays a vital role in processing auditory information, including speech. The present study measured brain stem frequency-following responses (FFR) evoked by forward and reverse speech stimuli recorded from electrodes oriented horizontally and vertically to measure signals with putative origins in auditory nerve and rostral brain stem, respectively. The vertical FFR showed increased amplitude due to forward speech. It is concluded that familiar phonological and prosodic properties of forward speech selectively activate central brain stem neurons.

  8. Auditory evoked response: a new approach for the evaluation of the unborn fetus.

    Science.gov (United States)

    Pereira Luz, N; Pereira Lima, C; Germany Paula, L; Hecker Luz, J

    1980-01-01

    The authors present their preliminary results observed with sound stimulation of human fetuses, a new approach to the exploration of some brain functions during fetal life, using a behavioural procedure. By applying an adequate auditory stimulus to the abdomen of pregnant women in the last trimester of pregnancy and during labour, they were able to evoke a standard fetal heart rate and motor response. They describe the different patterns observed during labour as a preliminary report of what appears to be a new procedure for evaluation of fetal conditions in normal or abnormal environments.

  9. Concurrent OCT imaging of stimulus evoked retinal neural activation and hemodynamic responses

    Science.gov (United States)

    Son, Taeyoon; Wang, Benquan; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2017-02-01

    It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation. These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases, which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye diseases.

  10. Review of evoked and event-related delta responses in the human brain.

    Science.gov (United States)

    Güntekin, Bahar; Başar, Erol

    2016-05-01

    In the last decade, the brain's oscillatory responses have invaded the literature. The studies on delta (0.5-3.5Hz) oscillatory responses in humans upon application of cognitive paradigms showed that delta oscillations are related to cognitive processes, mainly in decision making and attentional processes. The present manuscript comprehensively reviews the studies on delta oscillatory responses upon cognitive stimulation in healthy subjects and in different pathologies, namely Alzheimer's disease, Mild Cognitive Impairment (MCI), bipolar disorder, schizophrenia and alcoholism. Further delta oscillatory response upon presentation of faces, facial expressions, and affective pictures are reviewed. The relationship between pre-stimulus delta activity and post-stimulus evoked and event-related responses and/or oscillations is discussed. Cross-frequency couplings of delta oscillations with higher frequency windows are also included in the review. The conclusion of this review includes several important remarks, including that delta oscillatory responses are involved in cognitive and emotional processes. A decrease of delta oscillatory responses could be a general electrophysiological marker for cognitive dysfunction (Alzheimer's disease, MCI, bipolar disorder, schizophrenia and alcoholism). The pre-stimulus activity (phase or amplitude changes in delta activity) has an effect on post-stimulus EEG responses. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Chronic lower limb wounds evoke systemic response of the lymphatic (immune system

    Directory of Open Access Journals (Sweden)

    W L Olszewski

    2012-01-01

    Full Text Available Wound healing should not be considered as a process limited only to the damaged tissues. It is always accompanied by an intensive local immune response and in advanced stages, the systemic lymphatic (immune structure. In this review we present evidence from our own studies as well as pertinent literature on the role of skin and subcutaneous tissue lymphatics at the wound site and of transport of antigens along with collecting afferent lymphatics to the lymph nodes. We also speculate the role of lymph nodes in raising cohorts of bacterial and own tissue antigen-specific lymphocytes and their participation in healing and not infrequently evoking uncontrolled chronic immune reaction causing a delay of healing. It is also speculated as to why there is a rapid response of lymph node cells to microbial antigens and tolerance to damaged-tissue-derived antigens occurs

  12. 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.

    2009-01-01

    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

  13. Effects of intraocular mescaline and LSD on visual-evoked responses in the rat.

    Science.gov (United States)

    Eells, J T; Wilkison, D M

    1989-01-01

    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.

  14. Normal Amplitude of Electroretinography and Visual Evoked Potential Responses in AβPP/PS1 Mice.

    Science.gov (United States)

    Leinonen, Henri; Lipponen, Arto; Gurevicius, Kestutis; Tanila, Heikki

    2016-01-01

    Alzheimer's disease has been shown to affect vision in human patients and animal models. This may pose the risk of bias in behavior studies and therefore requires comprehensive investigation. We recorded electroretinography (ERG) under isoflurane anesthesia and visual evoked potentials (VEP) in awake amyloid expressing AβPPswe/PS1dE9 (AβPP/PS1) and wild-type littermate mice at a symptomatic age. The VEPs in response to patterned stimuli were normal in AβPP/PS1 mice. They also showed normal ERG amplitude but slightly shortened ERG latency in dark-adapted conditions. Our results indicate subtle changes in visual processing in aged male AβPP/PS1 mice specifically at a retinal level.

  15. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered.

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Pialasse

    Full Text Available Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20 or severe (n = 16 spine deformation were compared to those of healthy control adolescents (n = 16. Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes.

  16. Infant temperament and the brainstem auditory evoked response in later childhood.

    Science.gov (United States)

    Woodward, S A; McManis, M H; Kagan, J; Deldin, P; Snidman, N; Lewis, M; Kahn, V

    2001-07-01

    Brainstem auditory evoked responses (BAERs) were evaluated on 10-12-year-old children (N = 56) who had been classified as high or low reactive to unfamiliar stimuli at 4 months of age. BAER measurement was selected because high reactive infants tend to become inhibited or fearful young children, and adult introverts have a faster latency to wave V of the BAER than do extroverts. Children previously classified as high reactive at 4 months had larger wave V components than did low reactive children, a finding that possibly suggests greater excitability in projections to the inferior colliculus. The fact that a fundamental feature of brainstem activity differentiated preadolescent children belonging to two early temperamental groups supports the value of gathering physiological data in temperament research.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-10-01

    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).

  18. 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.

  19. The thermosensitive potassium channel TREK-1 contributes to coolness-evoked responses of Grueneberg ganglion neurons.

    Science.gov (United States)

    Stebe, Sabrina; Schellig, Katharina; Lesage, Florian; Breer, Heinz; Fleischer, Joerg

    2014-01-01

    Neurons of the Grueneberg ganglion (GG) residing in the vestibule of the murine nose are activated by cool ambient temperatures. Activation of thermosensory neurons is usually mediated by thermosensitive ion channels of the transient receptor potential (TRP) family. However, there is no evidence for the expression of thermo-TRPs in the GG, suggesting that GG neurons utilize distinct mechanisms for their responsiveness to cool temperatures. In search for proteins that render GG neurons responsive to coolness, we have investigated whether TREK/TRAAK channels may play a role; in heterologous expression systems, these potassium channels have been previously found to close upon exposure to coolness, leading to a membrane depolarization. The results of the present study indicate that the thermosensitive potassium channel TREK-1 is expressed in those GG neurons that are responsive to cool temperatures. Studies analyzing TREK-deficient mice revealed that coolness-evoked responses of GG neurons were clearly attenuated in these animals compared with wild-type conspecifics. These data suggest that TREK-1 channels significantly contribute to the responsiveness of GG neurons to cool temperatures, further supporting the concept that TREK channels serve as thermoreceptors in sensory cells. Moreover, the present findings provide the first evidence of how thermosensory GG neurons are activated by given temperature stimuli in the absence of thermo-TRPs.

  20. 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

    2013-01-01

    Increased neuron and astrocyte activity triggers increased brain blood flow, but controversy exists over whether stimulation-induced changes in astrocyte activity are rapid and widespread enough to contribute to brain blood flow control. Here, we provide evidence for stimulus-evoked Ca(2+) elevat...... brief Ca(2+) responses with a rapid onset in vivo, fast enough to initiate hemodynamic responses or influence synaptic activity.......Increased neuron and astrocyte activity triggers increased brain blood flow, but controversy exists over whether stimulation-induced changes in astrocyte activity are rapid and widespread enough to contribute to brain blood flow control. Here, we provide evidence for stimulus-evoked Ca(2......+) elevations with rapid onset and short duration in a large proportion of cortical astrocytes in the adult mouse somatosensory cortex. Our improved detection of the fast Ca(2+) signals is due to a signal-enhancing analysis of the Ca(2+) activity. The rapid stimulation-evoked Ca(2+) increases identified...

  1. Cortically evoked responses of human pallidal neurons recorded during stereotactic neurosurgery.

    Science.gov (United States)

    Nishibayashi, Hiroki; Ogura, Mitsuhiro; Kakishita, Koji; Tanaka, Satoshi; Tachibana, Yoshihisa; Nambu, Atsushi; Kita, Hitoshi; Itakura, Toru

    2011-02-15

    Responses of neurons in the globus pallidus (GP) to cortical stimulation were recorded for the first time in humans. We performed microelectrode recordings of GP neurons in 10 Parkinson's disease (PD) patients and 1 cervical dystonia (CD) patient during surgeries to implant bilateral deep brain stimulation electrodes in the GP. To identify the motor territories in the external (GPe) and internal (GPi) segments of the GP, unitary responses evoked by stimulation of the primary motor cortex were observed by constructing peristimulus time histograms. Neurons in the motor territories of the GPe and GPi responded to cortical stimulation. Response patterns observed in the PD patients were combinations of an early excitation, an inhibition, and a late excitation. In addition, in the CD patient, a long-lasting inhibition was prominent, suggesting increased activity along the cortico-striato-GPe/GPi pathways. The firing rates of GPe and GPi neurons in the CD patient were lower than those in the PD patients. Many GPe and GPi neurons of the PD and CD patients showed burst or oscillatory burst activity. Effective cathodal contacts tended to be located close to the responding neurons. Such unitary responses induced by cortical stimulation may be of use to target motor territories of the GP for stereotactic functional neurosurgery. Future findings utilizing this method may give us new insights into understanding the pathophysiology of movement disorders. Copyright © 2011 Movement Disorder Society.

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

    Directory of Open Access Journals (Sweden)

    Kida Tetsuo

    2009-04-01

    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.

  3. 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

    2015-01-01

    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......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 roundtrip delays have been related to properties of the dispersive cochlea and internal reflections. Temporal suppression experiments (e.g. Kemp and Chum, 1980; Verhulst et al., 2008), where a suppressor click is presented just before the stimulus click, have shown how a click response depends on preceding...... 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...

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

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    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.

  5. 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.

  6. Chance-constrained optimization of demand response to price signals

    DEFF Research Database (Denmark)

    Dorini, Gianluca Fabio; Pinson, Pierre; Madsen, Henrik

    2013-01-01

    Household-based demand response is expected to play an increasing role in supporting the large scale integration of renewable energy generation in existing power systems and electricity markets. While the direct control of the consumption level of households is envisaged as a possibility......, a credible alternative is that of indirect control based on price signals to be sent to these end-consumers. A methodology is described here allowing to estimate in advance the potential response of flexible end-consumers to price variations, subsequently embedded in an optimal price-signal generator....... In contrast to some real-time pricing proposals in the literature, here prices are estimated and broadcast once a day for the following one, for households to optimally schedule their consumption. The price-response is modeled using stochastic finite impulse response (FIR) models. Parameters are estimated...

  7. Evoked response of heart rate variability using short-duration white noise.

    Science.gov (United States)

    Lee, Guo-She; Chen, Mei-Ling; Wang, Gin-You

    2010-06-24

    To investigate and to establish a model for evaluation of the instant cardiovascular responses to the noises of low-to-moderate intensity, sixteen healthy subjects were enrolled. The white noises were binaurally presented with a supra-aural earphone. The test intensities of noises were no noise, 50, 60, 70 and 80 dBA. Each noise was continued for 5 min and the electrocardiogram was simultaneously recorded. The cardiac autonomic responses were evaluated using power spectral analysis of the R-R contour obtained from digital signal processing of the ECG tracings. The result showed that the mean heart rate and mean blood pressure did not change significantly with the noises. However, the low-frequency power (LF) which represents cardiac autonomic modulations and the ratio (LHR) of LF to high-frequency power (HF) which reflects cardiac sympathetic modulations were significantly greater in the noise intensity of 50, 60, 70 and 80dBA (pnoise intensity (rho=0.90, pwhite noises can be detected using power spectral analysis of heart rate variability and the evoked responses may provide a sensitive way to evaluate the instant effect of noise to humans.

  8. Impact of loudness dependency of auditory evoked potentials on the panic response to CCK-4.

    Science.gov (United States)

    Eser, Daniela; Leicht, Gregor; Baghai, Thomas; Pogarell, Oliver; Schüle, Cornelius; Karch, Susanne; Nothdurfter, Caroline; Rupprecht, Rainer; Mulert, Christoph

    2009-01-01

    Experimental panic induction with cholecystokinin-tetrapeptide (CCK-4) has been established as a model to study the pathophysiology of panic disorder. In line with the serotonin (5-HT)-hypothesis of panic disorder it has been suggested that the panicogenic effects of CCK-4 are mediated in part through the 5-HT system. The analysis of the loudness dependency of the auditory evoked potentials (LDAEP) is a valid non-invasive indicator of central serotonergic activity. We investigated the correlation between LDAEP and behavioral, cardiovascular and neuroendocrine panic responses to CCK-4in 77 healthy volunteers and explored whether differences in LDAEP paralleled subjective panic severity. Behavioral panic responses were measured with the panic symptom scale (PSS). Heart rate and ACTH/cortisol plasma concentrations were assessed concomitantly. LDAEP did not differ between panickers and nonpanickers. Furthermore, LDAEP did not correlate with the behavioral panic response. However, a significant positive correlation between LDAEP and CCK-4 induced HPA-axis activation, which was uniform in panickers and nonpanickers, could be detected. The psychological effects of CCK-4 rather are mediated by neurotransmitters others than the endogenous 5-HT system. However, the extent of the neuroendocrine activation related to the CCK-4 panic provocation was correlated with the LDAEP, thereby suggesting that central 5-HT mechanisms are involved in the HPA-axis activation during this challenge paradigm.

  9. Wavelet denoising of EEG signals and identification of evoked response potentials

    Science.gov (United States)

    Carmona, Rene A.; Hudgins, Lonnie H.

    1994-10-01

    The purpose of this study is to apply a recently developed wavelet based de-noising filter to the analysis of human electroencephalogram (EEG) signals, and measure its performance. The data used contained subject EEG responses to two different stimuli using the `odd-ball' paradigm. Electrical signals measured at standard locations on the scalp were processed to detect and identify the Evoked Response Potentials (ERP's). First, electrical artifacts emitting from the eyes were identified and removed. Second, the mean signature for each type of response was extracted and used as a matched filter to define baseline detector performance for the noisy data. Third, a nonlinear filtering procedure based on the wavelet extrema representation was used to de-noise the signals. Overall detection rates for the de-noised signals were then compared to the baseline performance. It was found that while the filtered signals have significantly lower noise than the raw signals, detector performance remains comparable. We therefore conclude that all of the information that is important to matched filter detection is preserved by the filter. The implication is that the wavelet based filter eliminates much of the noise while retaining ERP's.

  10. Gender differences in rival characteristics that evoke jealousy in response to emotional versus sexual infidelity

    NARCIS (Netherlands)

    Buunk, Abraham (Bram); Dijkstra, Pieternel

    2004-01-01

    Previous research has shown that in men jealousy is evoked more by a rival's status-related characteristics than in women, whereas in women jealousy is evoked more by a rival's physical attractiveness than in men. The present study examined whether the occurrence of this gender difference depends

  11. 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

  12. 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

    1980-01-01

    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...

  13. Neural responses to nostalgia-evoking music modeled by elements of dynamic musical structure and individual differences in affective traits.

    Science.gov (United States)

    Barrett, Frederick S; Janata, Petr

    2016-10-01

    Nostalgia is an emotion that is most commonly associated with personally and socially relevant memories. It is primarily positive in valence and is readily evoked by music. It is also an idiosyncratic experience that varies between individuals based on affective traits. We identified frontal, limbic, paralimbic, and midbrain brain regions in which the strength of the relationship between ratings of nostalgia evoked by music and blood-oxygen-level-dependent (BOLD) signal was predicted by affective personality measures (nostalgia proneness and the sadness scale of the Affective Neuroscience Personality Scales) that are known to modulate the strength of nostalgic experiences. We also identified brain areas including the inferior frontal gyrus, substantia nigra, cerebellum, and insula in which time-varying BOLD activity correlated more strongly with the time-varying tonal structure of nostalgia-evoking music than with music that evoked no or little nostalgia. These findings illustrate one way in which the reward and emotion regulation networks of the brain are recruited during the experiencing of complex emotional experiences triggered by music. These findings also highlight the importance of considering individual differences when examining the neural responses to strong and idiosyncratic emotional experiences. Finally, these findings provide a further demonstration of the use of time-varying stimulus-specific information in the investigation of music-evoked experiences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Frequency characteristics of human muscle and cortical responses evoked by noisy Achilles tendon vibration.

    Science.gov (United States)

    Mildren, Robyn L; Peters, Ryan M; Hill, Aimee J; Blouin, Jean-Sébastien; Carpenter, Mark G; Inglis, J Timothy

    2017-05-01

    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 somatosensory 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 2 min 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 was 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 1 ) accurate reflex estimates could be obtained with vibration; 2 ) responses did not habituate over 2 min of exposure; and importantly, 3 ) noisy vibration had a minimal influence on standing balance. Our findings suggest noisy tendon vibration is an effective novel approach to characterize somatosensory reflexes during standing. NEW & NOTEWORTHY We applied noisy (10-115 Hz) vibration to the Achilles tendon to examine the frequency characteristics of lower limb somatosensory reflexes during standing. Ongoing muscle activity was coherent with the noisy vibration (peak coherence ~40 Hz), and

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

    Directory of Open Access Journals (Sweden)

    Inyong eChoi

    2013-04-01

    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.

  16. Not all reading is alike: Task modulation of magnetic evoked response to visual word

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    Pavlova A. A.

    2017-09-01

    Full Text Available Background. Previous studies have shown that brain response to a written word depends on the task: whether the word is a target in a version of lexical decision task or should be read silently. Although this effect has been interpreted as an evidence for an interaction between word recognition processes and task demands, it also may be caused by greater attention allocation to the target word. Objective. We aimed to examine the task effect on brain response evoked by non- target written words. Design. Using MEG and magnetic source imaging, we compared spatial-temporal pattern of brain response elicited by a noun cue when it was read silently either without additional task (SR or with a requirement to produce an associated verb (VG. Results.The task demands penetrated into early (200-300 ms and late (500-800 ms stages of a word processing by enhancing brain response under VG versus SR condition. The cortical sources of the early response were localized to bilateral inferior occipitotemporal and anterior temporal cortex suggesting that more demanding VG task required elaborated lexical-semantic analysis. The late effect was observed in the associative auditory areas in middle and superior temporal gyri and in motor representation of articulators. Our results suggest that a remote goal plays a pivotal role in enhanced recruitment of cortical structures underlying orthographic, semantic and sensorimotor dimensions of written word perception from the early processing stages. Surprisingly, we found that to fulfil a more challenging goal the brain progressively engaged resources of the right hemisphere throughout all stages of silent reading. Conclusion. Our study demonstrates that a deeper processing of linguistic input amplifies activation of brain areas involved in integration of speech perception and production. This is consistent with theories that emphasize the role of sensorimotor integration in speech understanding.

  17. Baroreflexes of the rat. IV. ADN-evoked responses at the NTS.

    Science.gov (United States)

    Tang, Xiaorui; Dworkin, Barry R

    2007-12-01

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

    Directory of Open Access Journals (Sweden)

    Bronson Blake Harry

    2013-10-01

    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.

  19. Brainstem auditory-evoked response (BAER) in client-owned pet ferrets with normal hearing.

    Science.gov (United States)

    Piazza, S; Huynh, M; Cauzinille, L

    2014-06-07

    The objective of this study was to evaluate the feasibility of brainstem auditory-evoked response (BAER) testing in pet ferrets in a clinical setting, and to describe a routine method and baseline data for normal hearing ferrets for future investigation of deafness in this species. Twenty-eight clinically normal client-owned ferrets were included. BAER measurements were recorded under general anaesthesia (isoflurane delivered by mask), from subcutaneously placed needle electrodes. A 'click' stimulus applied by insert earphone with an intensity of 90 dB sound pressure level (SPL) was used. The final BAER waveform represents an average of 500 successive responses. Morphology of the waveform was studied; amplitude and latency measures were determined and means were calculated. The BAER waveform of the normal ferret included 4 reproducible waves named I, II, III and V, as previously described in dogs and cats. Measurements of latencies are consistent with previous laboratory research using experimental ferrets. In the present study, a reliable routine protocol for clinical evaluation of the hearing function in the pet ferret was established. This procedure can be easily and safely performed in a clinical setting in ferrets as young as eight weeks of age. The prevalence of congenital deafness in ferrets is currently unknown but may be an important consideration, especially in ferrets with a white coat. BAER test is a useful screening for congenital deafness in this species. British Veterinary Association.

  20. The BOLD response and the gamma oscillations respond differently than evoked potentials: an interleaved EEG-fMRI study

    Directory of Open Access Journals (Sweden)

    Gounot Daniel

    2003-09-01

    Full Text Available Abstract Background The integration of EEG and fMRI is attractive because of their complementary precision regarding time and space. But the relationship between the indirect hemodynamic fMRI signal and the more direct EEG signal is uncertain. Event-related EEG responses can be analyzed in two different ways, reflecting two different kinds of brain activity: evoked, i.e. phase-locked to the stimulus, such as evoked potentials, or induced, i.e. non phase-locked to the stimulus such as event-related oscillations. In order to determine which kind of EEG activity was more closely related with fMRI, EEG and fMRI signals were acquired together, while subjects were presented with two kinds of rare events intermingled with frequent distractors. Target events had to be signaled by pressing a button and Novel events had to be ignored. Results Both Targets and Novels triggered a P300, of larger amplitude in the Novel condition. On the opposite, the fMRI BOLD response was stronger in the Target condition. EEG event-related oscillations in the gamma band (32–38 Hz reacted in a way similar to the BOLD response. Conclusions The reasons for such opposite differential reactivity between oscillations / fMRI on the one hand, and evoked potentials on the other, are discussed in the paper. Those results provide further arguments for a closer relationship between fast oscillations and the BOLD signal, than between evoked potentials and the BOLD signal.

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

    NARCIS (Netherlands)

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

    2007-01-01

    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

  2. Revealing the distinction between perception and cognition through intra-individual variability of visual evoked responses.

    Science.gov (United States)

    Constantinescu, V D

    1996-01-01

    Searching for a method to objectively detect the cognitive activity of the brain, the variability of visual evoked responses (ER) was analysed in 75 human subjects and 10 animals. The individual ERs of a normal subject were found typically very scattered in the first approx. 120 ms after stimulation, converging at 160-220 ms and then diverging again progressively. This variability pattern (VP) is event-related and is not attributable to background noise. On the other hand, statistically significant correlation showed that in most patients, with anatomically intact visual structures but with pronounced mental troubles, the VP is absent and the ERs are randomly scattered. Based on these results we consider that the event-related variability reflects the cognition function of the subjects and that it is instrumental in evidencing the distinction between cognitive and perceptive processes. The results are further consistent with the idea that cognition implies the chaotic activity of certain neural populations and that the VP reflects this chaotic, non-repetitive, non-linear and impredictable but effective neural activity.

  3. Effects of otitis on hearing in dogs characterised by brainstem auditory evoked response testing.

    Science.gov (United States)

    Eger, C E; Lindsay, P

    1997-09-01

    Hearing function was measured in normal dogs and in dogs with otitis using brainstem auditory evoked response testing. Data were obtained from 86 normal ears and from 105 ears with otitis, categorised into four degrees of severity. The data were analysed to illustrate the differences between the hearing function in the normal and abnormal ears and to estimate the degree of impairment associated with differing degrees of pathology. While severe hearing loss seemed to be present in the dogs with more severe otitis, only two individuals were identified as being totally deaf in the affected ears and no dogs were identified in which the cleaning and examination processes had caused damage to hearing function. Cleaning the ear canal produced measurable improvements in hearing in several dogs, indicating the profound effect of physical obstruction of the external ear canal by debris. It is concluded that most dogs with chronic otitis externa are not totally deaf and that the hearing impairment that does occur has the characteristics of conductive hearing loss.

  4. Gender Disparities in Speech-evoked Auditory Brainstem Response in Healthy Adults.

    Science.gov (United States)

    Jalaei, Bahram; Zakaria, Mohd Normani; Mohd Azmi, Mohd Hafiz Afifi; Nik Othman, Nik Adilah; Sidek, Dinsuhaimi

    2017-04-01

    Gender disparities in speech-evoked auditory brainstem response (speech-ABR) outcomes have been reported, but the literature is limited. The present study was performed to further verify this issue and determine the influence of head size on speech-ABR results between genders. Twenty-nine healthy Malaysian subjects (14 males and 15 females) aged 19 to 30 years participated in this study. After measuring the head circumference, speech-ABR was recorded by using synthesized syllable /da/ from the right ear of each participant. Speech-ABR peaks amplitudes, peaks latencies, and composite onset measures were computed and analyzed. Significant gender disparities were noted in the transient component but not in the sustained component of speech-ABR. Statistically higher V/A amplitudes and less steeper V/A slopes were found in females. These gender differences were partially affected after controlling for the head size. Head size is not the main contributing factor for gender disparities in speech-ABR outcomes. Gender-specific normative data can be useful when recording speech-ABR for clinical purposes.

  5. Middle latency auditory evoked responses in normal term infants: a longitudinal study.

    Science.gov (United States)

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

    1989-05-01

    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.

  6. Cow's milk challenge through human milk evokes immune responses in infants with cow's milk allergy.

    Science.gov (United States)

    Järvinen, K M; Mäkinen-Kiljunen, S; Suomalainen, H

    1999-10-01

    In order to measure the immune response evoked in breast-fed infants with cow's milk allergy (CMA) by cow's milk challenge through human milk, mothers were given increasing doses of cow's milk after they had been on a cow's milk elimination diet. Another objective was to study the secretion of beta-lactoglobulin (BLG) into human milk before and during milk challenge in relation to the appearance of symptoms in infants. Seventeen asymptomatic mothers who had infants with challenge-proven CMA and 10 asymptomatic mothers who had healthy infants were recruited. Infants ranged in age from 1.8 to 9.4 months. A solid-phase enzyme-linked immunoassay (ELISPOT) was used to assess the total number of immunoglobulin-secreting and specific antibody-secreting cells. Flow cytometry was used to enumerate different lymphocyte subpopulations among peripheral blood lymphocytes primed during provocation by cow's milk antigens. BLG levels were assessed in human milk before the challenge and 1, 2, 3, and 4 hours after the commencement of the challenge. All but one of the infants with CMA showed symptoms of CMA during cow's milk challenge through human milk. There was a significant rise in the total number of immunoglobulin-secreting cells in the IgA and IgG classes associated with a positive cow's milk challenge response, but the proportions of peripheral blood B cells bearing CD19, CD23, CD19 and 23, CD5, or CD19 and CD5 were comparable. BLG levels were comparable in both study groups. Most of the infants with CMA reacted to cow's milk challenge through human milk. Hypersensitivity reactions to food antigens through human milk may be more common than previously thought.

  7. Frequency-specific objective audiometry: tone-evoked brainstem responses and steady-state responses to 40 Hz and 90 Hz amplitude modulated stimuli.

    NARCIS (Netherlands)

    Reijden, C.S. van der; Mens, L.H.M.; Snik, A.F.M.

    2006-01-01

    Tone-evoked Auditory Brainstem Responses (tone-burst ABRs) and Auditory Steady-State Responses (ASSRs) with 40 or 90 Hz amplitude modulation (AM) were compared, using the same equipment and recording parameters, to determine which of these three methods most accurately approached the behavioural

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

    Directory of Open Access Journals (Sweden)

    Okamoto Hidehiko

    2009-12-01

    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

  9. A comparison of the brainstem auditory evoked response in healthy ears of unilaterally deaf dogs and bilaterally hearing dogs.

    Science.gov (United States)

    Plonek, M; Nicpoń, J; Kubiak, K; Wrzosek, M

    2017-03-01

    Auditory plasticity in response to unilateral deafness has been reported in various animal species. Subcortical changes occurring in unilaterally deaf young dogs using the brainstem auditory evoked response have not been evaluated yet. The aim of this study was to assess the brainstem auditory evoked response findings in dogs with unilateral hearing loss, and compare them with recordings obtained from healthy dogs. Brainstem auditory evoked responses (amplitudes and latencies of waves I, II, III, V, the V/I wave amplitude ratio, wave I-V, I-III and III-V interpeak intervals) were studied retrospectively in forty-six privately owned dogs, which were either unilaterally deaf or had bilateral hearing. The data obtained from the hearing ears in unilaterally deaf dogs were compared to values obtained from their healthy littermates. Statistically significant differences in the amplitude of wave III and the V/I wave amplitude ratio at 75 dB nHL were found between the group of unilaterally deaf puppies and the control group. The recordings of dogs with single-sided deafness were compared, and the results showed no statistically significant differences in the latencies and amplitudes of the waves between left- (AL) and right-sided (AR) deafness. The recordings of the brainstem auditory evoked response in canines with unilateral inborn deafness in this study varied compared to recordings from healthy dogs. Future studies looking into electrophysiological assessment of hearing in conjunction with imaging modalities to determine subcortical auditory plasticity and auditory lateralization in unilaterally deaf dogs are warranted.

  10. Detection of binaural interaction in free-field evoked auditory brainstem responses by time-scale representations.

    Science.gov (United States)

    Schebsdat, Erik; Hessel, Horst; Seidler, Harald; Strauss, Daniel J

    2016-08-01

    The so called β-wave of the binaural interaction component (BIC) in auditory brainstem responses (ABR) has been shown to be an objective measure for binaural interaction (BI). This component is the arithmetical difference between the sum of the monaurally evoked ABRs and the binaurally evoked ABR. Unfortunately, these neural responses are known to be very fragile and as a result the calculated BIC. An additional issue is, that the findings of this measurement are predominantly needed in people with hearing loss who may use hearing devices like hearing aids (HA) or cochlear implants (CI), thus they are not able to use headphones (like in conventional ABR measurements) during the detection of possible BI. This is a crucial problem, because it is known that factors like the interaural time delay (ITD) between the receiving ears are responsible for solving tasks like sound source localization or sound source separation, but specially designed measurements to coordinate the fitting of HAs or CIs with respect to BI are still missing. In this paper, we introduce a new measurement setup that is able to detect BI depending on different ITDs in free-field evoked responses by using the more reliable instantaneous phase in the time-scale representation. With this pilot study we are able to demonstrate a decreasing BI with an increasing ITD using the wavelet phase synchronization stability analysis in ten normal hearing subjects.

  11. Brainstem auditory evoked responses in an equine patient population: part I--adult horses.

    Science.gov (United States)

    Aleman, M; Holliday, T A; Nieto, J E; Williams, D C

    2014-01-01

    Brainstem auditory evoked response has been an underused diagnostic modality in horses as evidenced by few reports on the subject. To describe BAER findings, common clinical signs, and causes of hearing loss in adult horses. Study group, 76 horses; control group, 8 horses. Retrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Horses were grouped under disease categories. Descriptive statistics and a posthoc Bonferroni test were performed. Fifty-seven of 76 horses had BAER deficits. There was no breed or sex predisposition, with the exception of American Paint horses diagnosed with congenital sensorineural deafness. Eighty-six percent (n = 49/57) of the horses were younger than 16 years of age. The most common causes of BAER abnormalities were temporohyoid osteoarthropathy (THO, n = 20/20; abnormalities/total), congenital sensorineural deafness in Paint horses (17/17), multifocal brain disease (13/16), and otitis media/interna (4/4). Auditory loss was bilateral and unilateral in 74% (n = 42/57) and 26% (n = 15/57) of the horses, respectively. The most common causes of bilateral auditory loss were sensorineural deafness, THO, and multifocal brain disease whereas THO and otitis were the most common causes of unilateral deficits. Auditory deficits should be investigated in horses with altered behavior, THO, multifocal brain disease, otitis, and in horses with certain coat and eye color patterns. BAER testing is an objective and noninvasive diagnostic modality to assess auditory function in horses. Copyright © 2014 by the American College of Veterinary Internal Medicine.

  12. P2X7R modulation of visually evoked synaptic responses in the retina.

    Science.gov (United States)

    Chavda, Seetal; Luthert, Philip J; Salt, Thomas E

    2016-12-01

    P2X7Rs are distributed throughout all layers of the retina, and thus, their localisation on various cell types puts into question their specific site(s) of action. Using a dark-adapted, ex vivo mouse retinal whole mount preparation, the present study aimed to characterise the effect of P2X7R activation on light-evoked, excitatory RGC ON-field excitatory post-synaptic potentials (fEPSPs) and on outer retinal electroretinogram (ERG) responses under comparable conditions. The pharmacologically isolated NMDA receptor-mediated RGC ON-fEPSP was reduced in the presence of BzATP, an effect which was significantly attenuated by A438079 and other selective P2X7R antagonists A804598 or AF27139. In physiological Krebs medium, BzATP induced a significant potentiation of the ERG a-wave, with a concomitant reduction in the b-wave and the power of the oscillatory potentials. Conversely, in the pharmacologically modified Mg2+-free perfusate, BzATP reduced both the a-wave and b-wave. The effects of BzATP on the ERG components were suppressed by A438079. A role for P2X7R function in visual processing in both the inner and outer retina under physiological conditions remains controversial. The ON-fEPSP was significantly reduced in the presence of A804598 but not by A438079 or AF27139. Furthermore, A438079 did not have any effect on the ERG components in physiological Krebs but potentiated and reduced the a-wave and b-wave, respectively, when applied to the pharmacologically modified medium. Therefore, activation of P2X7Rs affects the function in the retinal ON pathway. The presence of a high concentration of extracellular ATP would most likely contribute to the modulation of visual transmission in the retina in the pathophysiological microenvironment.

  13. Auditory assessment of children with severe hearing loss using behavioural observation audiometry and brainstem evoked response audiometry

    OpenAIRE

    Rakhi Kumari; Priyanko Chakraborty; Jain, R K; Dhananjay Kumar

    2016-01-01

    Background: Early detection of hearing loss has been a long-standing priority in the field of audiology. Currently available auditory testing methods include both behavioural and non-behavioural or objective tests of hearing. This study was planned with an objective to assess hearing loss in children using behavioural observation audiometry and brain stem evoked response audiometry. Methods: A total of 105 cases suffering from severe to profound hearing loss were registered. After proper h...

  14. Physical exercise affects the epigenetic programming of rat brain and modulates the adaptive response evoked by repeated restraint stress.

    Science.gov (United States)

    Kashimoto, R K; Toffoli, L V; Manfredo, M H F; Volpini, V L; Martins-Pinge, M C; Pelosi, G G; Gomes, M V

    2016-01-01

    Epigenetics has recently been linked to molecular adaptive responses evoked by physical exercise and stress. Herein we evaluated the effects of physical exercise on global DNA methylation and expression of the Dnmt1 gene in the rat brain and also verified its potential to modulate responses evoked by repeated restraint stress (RRS). Wistar rats were classified into the following experimental groups: (1) physically active (EX): animals submitted to swimming during postnatal days 53-78 (PND); (2) stress (ST): animals submitted to RRS during 75-79PND; (3) exercise-stress (EX-ST): animals submitted to swimming during 53-78PND and to RRS during 75-79PND, and (4) control (CTL): animals that were not submitted to intervention. Samples from the hippocampus, cortex and hypothalamus were obtained at 79PND. The global DNA methylation profile was assessed using an ELISA-based method and the expression of Dnmt1 was evaluated by real-time PCR. Significantly increased methylation was observed in the hypothalamus of animals from the EX group in comparison to CTL. Comparative analysis involving the EX-ST and ST groups revealed increased global DNA methylation in the hippocampus, cortex, and hypothalamus of EX-ST, indicating the potential of physical exercise in modulating the responses evoked by RRS. Furthermore, decreased expression of the Dnmt1 gene was observed in the hippocampus and hypothalamus of animals from the EX-ST group. In summary, our data indicate that physical exercise affects DNA methylation of the hypothalamus and might modulate epigenetic responses evoked by RRS in the hippocampus, cortex, and hypothalamus. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Source localization of EEG versus MEG: Emperical comparison using visually evoked responses and theoretical considerations

    NARCIS (Netherlands)

    Lopes da silva, F.H.; Wieringa, H.J.; Wieringa, H.J.; Peters, M.J.

    1991-01-01

    Theoretically, the information we can obtain about the functional localization of a source of brain activity from the scalp, for instance evoked by a sensory stimulus, is the same whether one uses EEG or MEG recordings. However, the nature of the sources and, especially of the volume conductor,

  16. Circulatory response evoked by a 3 s bout of dynamic leg exercise in humans

    NARCIS (Netherlands)

    Wieling, W.; Harms, M. P.; ten Harkel, A. D.; van Lieshout, J. J.; Sprangers, R. L.

    1996-01-01

    1. The mechanisms underlying the pronounced transient fall in arterial blood pressure evoked by a 3 s bout of bicycle exercise were investigated in twenty healthy young adults and four patients with hypoadrenergic orthostatic hypotension. 2. In healthy subjects a 3 s bout of upright cycling induced

  17. Quantification of baseline pupillary response and task-evoked pupillary response during constant and incremental task load.

    Science.gov (United States)

    Mosaly, Prithima R; Mazur, Lukasz M; Marks, Lawrence B

    2017-10-01

    The methods employed to quantify the baseline pupil size and task-evoked pupillary response (TEPR) may affect the overall study results. To test this hypothesis, the objective of this study was to assess variability in baseline pupil size and TEPR during two basic working memory tasks: constant load of 3-letters memorisation-recall (10 trials), and incremental load memorisation-recall (two trials of each load level), using two commonly used methods (1) change from trail/load specific baseline, (2) change from constant baseline. Results indicated that there was a significant shift in baseline between the trails for constant load, and between the load levels for incremental load. The TEPR was independent of shifts in baseline using method 1 only for constant load, and method 2 only for higher levels of incremental load condition. These important findings suggest that the assessment of both the baseline and methods to quantify TEPR are critical in ergonomics application, especially in studies with small number of trials per subject per condition. Practitioner Summary: Quantification of TEPR can be affected by shifts in baseline pupil size that are most likely affected by non-cognitive factors when other external factors are kept constant. Therefore, quantification methods employed to compute both baseline and TEPR are critical in understanding the information processing of humans in practical ergonomics settings.

  18. Development of an ultra low noise, miniature signal conditioning device for vestibular evoked response recordings.

    Science.gov (United States)

    Kumaragamage, Chathura L; Lithgow, Brian J; Moussavi, Zahra

    2014-01-27

    Inner ear evoked potentials are small amplitude (signals that require a low noise signal acquisition protocol for successful extraction; an existing such technique is Electrocochleography (ECOG). A novel variant of ECOG called Electrovestibulography (EVestG) is currently investigated by our group, which captures vestibular responses to a whole body tilt. The objective is to design and implement a bio-signal amplifier optimized for ECOG and EVestG, which will be superior in noise performance compared to low noise, general purpose devices available commercially. A high gain configuration is required (>85 dB) for such small signal recordings; thus, background power line interference (PLI) can have adverse effects. Active electrode shielding and driven-right-leg circuitry optimized for EVestG/ECOG recordings were investigated for PLI suppression. A parallel pre-amplifier design approach was investigated to realize low voltage, and current noise figures for the bio-signal amplifier. In comparison to the currently used device, PLI is significantly suppressed by the designed prototype (by >20 dB in specific test scenarios), and the prototype amplifier generated noise was measured to be 4.8 nV/Hz @ 1 kHz (0.45 μVRMS with bandwidth 10 Hz-10 kHz), which is lower than the currently used device generated noise of 7.8 nV/Hz @ 1 kHz (0.76 μVRMS). A low noise (noise contribution from the pre-amplifier, while maintaining the required bandwidth in high impedance measurements. Validation of the prototype device was conducted for actual ECOG recordings on humans that showed an increase (p Signal-to-Noise ratio (SNR), and for EVestG recordings using a synthetic ear model that showed a ~4% improvement (p noise and miniaturized bio-signal amplifier tailored for EVestG and ECOG. The increase in SNR for the implemented amplifier will reduce variability associated with bio-features extracted from such recordings; hence sensitivity and specificity measures associated with disease

  19. Association of Hemoglobin levels and Brainstem Auditory Evoked Responses in Lead-Exposed Children

    Science.gov (United States)

    Counter, S. Allen; Buchanan, Leo H.; Ortega, Fernando

    2012-01-01

    Objectives Decreased blood hemoglobin (HbB) levels and anemia have been associated with abnormal brainstem auditory evoked responses (BAER). Lead (Pb) exposure has also been associated with anemia and aberrant BAER. This study investigated the relationship between HbB level and BAER wave latency and amplitude in Pb-exposed Andean children. Design and methods Sixty-six children aged 2 to 15 years (mean age: 9.1; SD: 3.3) living in Pb-contaminated villages were screened for HbB levels, blood Pb (PbB) levels and BAER latencies and amplitudes. Results The mean HbB level observed in the study group was 11.9 g/dL (SD: 1.4; range: 8.6–14.8 g/dL). The mean HbB level corrected for altitude was 10.3 g/dL (SD: 1.4; range: 6.9–13.1 g/dL), and suggestive of anemia. The mean PbB level was 49.3 μg/dL (SD: 30.1; range: 4.4–119.1 μg/dL) and indicative of Pb poisoning. Spearman Rho correlation analyses revealed significant associations between the BAER absolute latencies and HbB level, indicating that as the HbB level decreased, the BAER wave latency increased. Children with low HbB levels (≤11 g/dL) showed significantly prolonged absolute latencies of waves I, II, III, IV and V compared to the children with normal HbB levels. Although a significant relationship between HbB and BAER waves was observed, no significant associations between PbB level and BAER parameters were found. Conclusion Low hemoglobin levels may diminish auditory sensory-neural function, and is therefore an important variable to consider when assessing BAER in children with anemia and/or Pb exposure. PMID:22735387

  20. Optic nerve axonal pathology is related to abnormal visual evoked responses in AIDS.

    Science.gov (United States)

    Mahadevan, Anita; Satishchandra, Parthasarathy; Prachet, Krishnamurthy Kulkarni; Sidappa, Nagadenahalli Byrareddy; Ranga, Udaykumar; Santosh, Vani; Yasha, Thagadur Chickabasavaiah; Desai, Anita; Ravi, Vasanthapuram; Shankar, Susarla Krishna

    2006-10-01

    Electrophysiological studies in subjects with HIV/AIDS demonstrate subtle changes in the visual pathway even in the absence of visual symptoms. But the pathological correlate of the electrophysiological abnormalities is largely unknown. This study attempts to correlate pathological changes in the retina and intraorbital portion of optic nerve in four drug naïve patients of AIDS caused by HIV-1 clade C, who had abnormalities in the visual evoked potentials recorded antemortem. Three had no visual complaints and one patient had sudden loss of vision in the right eye. In all four patients, the visual evoked potentials disclosed variable prolongation of P100 latencies. Histologically axonal cytoskeletal breakdown and depletion in the optic nerves was the cardinal finding with variable myelin loss, even in the absence of overt visual dysfunction, or infective retinitis. The axonal loss was maximal in the symptomatic case. Retinal ganglion cell depletion was seen in only two patients. Sectoral infiltration of the optic nerve by cryptococci and Cryptococcal choroiditis was the only opportunistic infection to involve the eye. Axonal pathology in the optic nerve appears to be related to the abnormalities recorded in visual evoked potentials even in the absence of overt clinical symptoms. Opportunistic infections could be contributing to the axonal pathology in the optic nerve in patients with AIDS.

  1. Evoked cavernous activity.

    Science.gov (United States)

    Yilmaz, Uğur; Soylu, Ahmet; Ozcan, Cemal; Kutlu, Ramazan; Güneş, Ali

    2002-01-01

    Corpus cavernosum electromyography has been widely done to evaluate autonomic dysfunction in patients with erectile dysfunction. We assessed the value of corpus cavernosum electromyography, evoked cavernous activity and penile sympathetic skin responses for their accuracy in determining autonomic involvement in cases of erectile dysfunction. We evaluated 75 men with erectile dysfunction by corpus cavernosum electromyography, evoked cavernous activity and penile sympathetic skin response tests at our neurourology laboratory. The etiology of dysfunction was vascular, neurogenic, psychogenic or mixed based on a detailed medical and sexual history, physical examination, electrophysiological and laboratory studies, penile color Doppler ultrasonography, and cavernosography and/or cavernosometry. Autonomic involvement was clinically assessed by systemic findings, such as orthostatic hypotension, impaired gastrointestinal motility, sinus dysrhythmia and secretomotor changes. A concentric electromyography needle placed in the right cavernous body was used to record corpus cavernosum electromyography and evoked cavernous activity. The right median nerve was stimulated electrically with 13 to 16 mA. to determine evoked cavernous activity and the penile sympathetic skin response. The latter response was recorded with silver disc electrodes placed on the left cavernous body. All tests were performed using an electromyography/evoked potential machine. We determined the relationships among corpus cavernosum electromyography, evoked cavernous activity and penile sympathetic skin response tests in respect to etiological factors. The 56 patients with normal corpus cavernosum electromyography activity had also evoked cavernous activity and a penile sympathetic skin response except for 1 with no penile sympathetic skin response but evoked cavernous activity. None of these patients had autonomic neuropathy. Of the 19 patients without corpus cavernosum electromyography activity 11 had

  2. Brainstem auditory evoked response in adolescents with acoustic mycotic neuroma due to environmental exposure to toxic molds.

    Science.gov (United States)

    Anyanwu, Ebere; Campbell, Andrew W; High, William

    2002-01-01

    Indoor air contamination with toxic opportunistic molds is an emerging health risk worldwide. Some of the opportunistic molds include: Stachybotrys chartarum, Aspergillus species (A. fumigatus, A. flavus, A. niger, A. versicolor etc.), Cadosporium, Alternaria, Penicillium, Trichoderma, Fusarium graminearum etc. These molds flourish in homes that are moist and damp. Reports of floods are now evident in many parts of the world. With these global changes in climatic conditions that favor the opportunistic mode of living among these molds, some health authorities are beginning to feel concerned about the diversity and the extent to which opportunistic molds can cause adverse health effects in humans. Mycotoxicosis is the collective name for all the diseases caused by toxic molds. Frequently, we have cases of acoustic neuroma due to mycotoxicity in our Center. Mycotic neuroma probably has not been reported before and the application of brainstem auditory evoked response (BAER) techniques in acoustic mycotic neuroma have not been reported either. The aim of this study, therefore, was to report cases and measurements of acoustic mycotic neuroma in adolescents using the brainstem auditory evoked response. The patients' case history, clinical neurological and neurobehavioral questionnaires were assessed. Then, the BAERs were recorded between Cz and Ai, with a second channel, Cz-Ac. The case histories and the questionnaires were analyzed in conjunction with the outcome of the objective brainstem auditory evoked response measurements. The prevalent subjective findings in the patients were headaches, memory loss, hearing loss, lack of concentration, fatigue, sleep disturbance, facial swelling, rashes, nosebleeds, diarrhea, abdominal pains and respiratory difficulties. Objective BAER showed overall abnormalities in all the patients. Although the waveform abnormalities varied, 1-3 interpeak latencies were abnormal in all the patients. Overall results showed the presence of

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

    DEFF Research Database (Denmark)

    Arnfred, S; He, Chen; Eder, D

    2000-01-01

    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......). Further studies of the PEP are needed to assess the influence of load manipulations and of muscle contraction and to explore the effect of attentional manipulation....

  4. The influence of anesthetic depth on motor evoked potential response during awake craniotomy

    OpenAIRE

    Ohtaki, Shunya

    2016-01-01

    術中のMEP(motor evoked potential)の振幅および潜時は麻酔深度に影響される. またMEP振幅のdeviationに関しても麻酔深度と相関し, 覚醒下ではdeviationが小さい. 覚醒下手術におけるMEPの測定は, 術中の運動機能評価をより正確に行うことが出来る可能性が示唆される.

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

    Directory of Open Access Journals (Sweden)

    Sepideh Sadaghiani

    2010-06-01

    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. Eugenol and carvacrol excite first- and second-order trigeminal neurons and enhance their heat-evoked responses.

    Science.gov (United States)

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

    2014-06-20

    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. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Feng eRong

    2011-05-01

    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.

  8. Visual evoked response in patients with severe carotid disease--functional transcranial doppler study of posterior circulation.

    Science.gov (United States)

    Roje Bedeković, Marina; Bosnar Puretić, Marijana; Lovrencić Huzjan, Arijana; Demarin, Vida

    2009-12-01

    The goal of this study was to evaluate the visual evoked response in posterior cerebral artery (PCA) by means of functional transcranial doppler in patients with severe carotid disease and to determine the hemodynamic effect of severe carotid disease on posterior circulation. Measurements were performed successively in the dark and during the white light stimulation in 49 patients with high-grade (70-99%) internal carotid artery (ICA) stenosis or occlusion and compared with 30 healthy age and sex matched subjects. Mean blood flow velocities (MBFV) (cm/s +/- 2SD) and mean reaction time (MRT) (s +/- 2SD) during three consecutive repetitive periods of 1 minute each were analyzed. MBFV in PCA during the white light stimulation and in the dark between the two groups didn't differ. MRT in patients showed a significantly prolonged visual evoked response in both affected (light: patients 29.36 +/- 14.46, controls 19.67 +/- 11.25, respectively, p dark: patients 35.25 +/- 11.9 controls 21.89 +/- 10.31, respectively, p dark: patients 33.13 +/- 11.12, controls 23.89 +/- 11.23, respectively, p circle that is necessary to be considered separately.

  9. The cortical responses to evoked clinical pain in patients with hip osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Mikkel Gram

    Full Text Available Experimental models have been used extensively to evaluate pain using e.g., visual analogue scales or electroencephalography (EEG. Stimulation using tonic pain has been shown to better mimic the unpleasantness of chronic pain, but has mainly been evoked by non-clinical stimuli. This study aims to, evaluate the EEG during clinical pain in patients scheduled for total hip replacement with control and resting conditions.The hip scheduled for replacement was moved by the examiner to evoke pain for 30 seconds while recording EEG. The control condition entailed movement of the opposite hip in a similar fashion and holding it for 30 seconds. In addition, EEG was recorded during the resting condition with open eyes. The relative spectral content was calculated from the EEG as well as functional connectivity using phase-lag index for frequency bands delta (1-4Hz, theta (4-8Hz, alpha (8-12Hz and beta (12-32Hz. A mixed model was used for statistical comparison between the three recording conditions.Spectral content differed between conditions in all bands. Functional connectivity differed in delta and theta frequency bands. Post-hoc analysis revealed differences between the painful and control condition in delta, theta and beta for spectral content. Pain during the hip rotation was correlated to the theta (r = -0.24 P = 0.03 and beta (r = 0.25 P = 0.02 content in the EEG.EEG differences during hip movements in the affected and unaffected hip appeared in the spectral beta and theta content. This was correlated to the reported pain perceived, pointing towards pain specific brain activity related to clinical pain.

  10. Constrained Ordination Analysis with Enrichment of Bell-Shaped Response Functions.

    Directory of Open Access Journals (Sweden)

    Yingjie Zhang

    Full Text Available Constrained ordination methods aims at finding an environmental gradient along which the species abundances are maximally separated. The species response functions, which describe the expected abundance as a function of the environmental score, are according to the ecological fundamental niche theory only meaningful if they are bell-shaped. Many classical model-based ordination methods, however, use quadratic regression models without imposing the bell-shape and thus allowing for meaningless U-shaped response functions. The analysis output (e.g. a biplot may therefore be potentially misleading and the conclusions are prone to errors. In this paper we present a log-likelihood ratio criterion with a penalisation term to enforce more bell-shaped response shapes. We report the results of a simulation study and apply our method to metagenomics data from microbial ecology.

  11. Pain Processing and Vegetative Dysfunction in Fibromyalgia: A Study by Sympathetic Skin Response and Laser Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Marina de Tommaso

    2017-01-01

    Full Text Available Background. A dysfunction of pain processing at central and peripheral levels was reported in fibromyalgia (FM. We aimed to correlate laser evoked potentials (LEPs, Sympathetic Skin Response (SSR, and clinical features in FM patients. Methods. Fifty FM patients and 30 age-matched controls underwent LEPs and SSR by the right hand and foot. The clinical evaluation included FM disability (FIQ and severity scores (WPI, anxiety (SAS and depression (SDS scales, and questionnaires for neuropathic pain (DN4. Results. The LEP P2 latency and amplitude and the SSR latency were increased in FM group. This latter feature was more evident in anxious patients. The LEPs habituation was reduced in FM patients and correlated to pain severity scores. In a significant number of patients (32% with higher DN4 and FIQ scores, SSR or LEP responses were absent. Conclusions. LEPs and SSR might contribute to clarifying the peripheral and central nervous system involvement in FM patients.

  12. An evil face? Verbal evaluative multi-CS conditioning enhances face-evoked mid-latency magnetoencephalographic responses

    Science.gov (United States)

    Junghöfer, Markus; Rehbein, Maimu Alissa; Maitzen, Julius; Schindler, Sebastian

    2017-01-01

    Abstract Humans have a remarkable capacity for rapid affective learning. For instance, using first-order US such as odors or electric shocks, magnetoencephalography (MEG) studies of multi-CS conditioning demonstrate enhanced early (<150 ms) and mid-latency (150–300 ms) visual evoked responses to affectively conditioned faces, together with changes in stimulus evaluation. However, particularly in social contexts, human affective learning is often mediated by language, a class of complex higher-order US. To elucidate mechanisms of this type of learning, we investigate how face processing changes following verbal evaluative multi-CS conditioning. Sixty neutral expression male faces were paired with phrases about aversive crimes (30) or neutral occupations (30). Post conditioning, aversively associated faces evoked stronger magnetic fields in a mid-latency interval between 220 and 320 ms, localized primarily in left visual cortex. Aversively paired faces were also rated as more arousing and more unpleasant, evaluative changes occurring both with and without contingency awareness. However, no early MEG effects were found, implying that verbal evaluative conditioning may require conceptual processing and does not engage rapid, possibly sub-cortical, pathways. Results demonstrate the efficacy of verbal evaluative multi-CS conditioning and indicate both common and distinct neural mechanisms of first- and higher-order multi-CS conditioning, thereby informing theories of associative learning. PMID:28008078

  13. An alternative strategy for universal infant hearing screening in tertiary hospitals with a high delivery rate, within a developing country, using transient evoked oto-acoustic emissions and brainstem evoked response audiometry.

    Science.gov (United States)

    Mathur, N N; Dhawan, R

    2007-07-01

    To formulate an alternative strategy for universal infants hearing screening in an Indian tertiary referral hospital with a high delivery rate, which could be extended to similar situations in other developing countries. The system should be able to diagnose, in a timely fashion, all infants with severe and profound hearing losses. One thousand newborn were randomly selected. All underwent testing with transient evoked oto-acoustic emissions (TEOAE) in the first 48 hours of life. All TEOAE failures were followed up and repeat tests were performed at three weeks, three months and six months of age. Infants with acceptable TEOAE results at any of the four ages were discharged from the study. Infants with unacceptable TEOAE results at all the four ages underwent brainstem evoked response audiometry and oto-endoscopy. The 'pass rate' for TEOAE testing was calculated for all four ages. The time taken to perform TEOAE and brainstem evoked response audiometry was recorded for all subjects. These recordings were statistically analysed to find the most suitable strategy for universal hearing screening in our hospital. The pass rate for TEOAE was 79.0 per cent at audiometry. Obstructed and collapsed external auditory canals were the two factors that significantly affected the specificity of TEOAE in infants results are generated, such that a larger number must undergo brainstem evoked response audiometry, wasting time and resources. This can easily be avoided by delaying TEOAE screening until three months of age, when it has a substantially lower false positive outcome. We expect that implementation of this alternative strategy in our hospital will maximise the benefits of such a programme.

  14. Roles of N-methyl-d-aspartate receptors during the sensory stimulation-evoked field potential responses in mouse cerebellar cortical molecular layer.

    Science.gov (United States)

    Xu, Yin-Hua; Zhang, Guang-Jian; Zhao, Jing-Tong; Chu, Chun-Ping; Li, Yu-Zi; Qiu, De-Lai

    2017-11-01

    The functions of N-methyl-d-aspartate receptors (NMDARs) in cerebellar cortex have been widely studied under in vitro condition, but their roles during the sensory stimulation-evoked responses in the cerebellar cortical molecular layer in living animals are currently unclear. We here investigated the roles of NMDARs during the air-puff stimulation on ipsilateral whisker pad-evoked field potential responses in cerebellar cortical molecular layer in urethane-anesthetized mice by electrophysiological recording and pharmacological methods. Our results showed that cerebellar surface administration of NMDA induced a dose-dependent decrease in amplitude of the facial stimulation-evoked inhibitory responses (P1) in the molecular layer, accompanied with decreases in decay time, half-width and area under curve (AUC) of P1. The IC50 of NMDA induced inhibition in amplitude of P1 was 46.5μM. In addition, application of NMDA induced significant increases in the decay time, half-width and AUC values of the facial stimulation-evoked excitatory responses (N1) in the molecular layer. Application of an NMDAR blocker, D-APV (250μM) abolished the facial stimulation-evoked P1 in the molecular layer. These results suggested that NMDARs play a critical role during the sensory information processing in cerebellar cortical molecular layer in vivo in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Independent component analysis for cochlear implant artifacts attenuation from electrically evoked auditory steady-state response measurements

    Science.gov (United States)

    Deprez, Hanne; Gransier, Robin; Hofmann, Michael; van Wieringen, Astrid; Wouters, Jan; Moonen, Marc

    2018-02-01

    Objective. Electrically evoked auditory steady-state responses (EASSRs) are potentially useful for objective cochlear implant (CI) fitting and follow-up of the auditory maturation in infants and children with a CI. EASSRs are recorded in the electro-encephalogram (EEG) in response to electrical stimulation with continuous pulse trains, and are distorted by significant CI artifacts related to this electrical stimulation. The aim of this study is to evaluate a CI artifacts attenuation method based on independent component analysis (ICA) for three EASSR datasets. Approach. ICA has often been used to remove CI artifacts from the EEG to record transient auditory responses, such as cortical evoked auditory potentials. Independent components (ICs) corresponding to CI artifacts are then often manually identified. In this study, an ICA based CI artifacts attenuation method was developed and evaluated for EASSR measurements with varying CI artifacts and EASSR characteristics. Artifactual ICs were automatically identified based on their spectrum. Main results. For 40 Hz amplitude modulation (AM) stimulation at comfort level, in high SNR recordings, ICA succeeded in removing CI artifacts from all recording channels, without distorting the EASSR. For lower SNR recordings, with 40 Hz AM stimulation at lower levels, or 90 Hz AM stimulation, ICA either distorted the EASSR or could not remove all CI artifacts in most subjects, except for two of the seven subjects tested with low level 40 Hz AM stimulation. Noise levels were reduced after ICA was applied, and up to 29 ICs were rejected, suggesting poor ICA separation quality. Significance. We hypothesize that ICA is capable of separating CI artifacts and EASSR in case the contralateral hemisphere is EASSR dominated. For small EASSRs or large CI artifact amplitudes, ICA separation quality is insufficient to ensure complete CI artifacts attenuation without EASSR distortion.

  16. The Effect of Lamotrigine and Levetiracetam on TMS-Evoked EEG Responses Depends on Stimulation Intensity

    Directory of Open Access Journals (Sweden)

    Isabella Premoli

    2017-10-01

    Full Text Available The combination of transcranial magnetic stimulation and electroencephalography (TMS-EEG has uncovered underlying mechanisms of two anti-epileptic medications: levetiracetam and lamotrigine. Despite their different mechanism of action, both drugs modulated TMS-evoked EEG potentials (TEPs in a similar way. Since both medications increase resting motor threshold (RMT, the current aim was to examine the similarities and differences in post-drug TEPs, depending on whether stimulation intensity was adjusted to take account of post-drug RMT increase. The experiment followed a placebo controlled, double blind, crossover design, involving a single dose of either lamotrigine or levetiracetam. When a drug-induced increase of RMT occurred, post-drug measurements involved two blocks of stimulations, using unadjusted and adjusted stimulation intensity. A cluster based permutation analysis of differences in TEP amplitude between adjusted and unadjusted stimulation intensity showed that lamotrigine induced a stronger modulation of the N45 TEP component compared to levetiracetam. Results highlight the impact of adjusting stimulation intensity.

  17. Assessment of Electrically Evoked Auditory Brain Stem Response of 30 Implanted Patients With Nucleus Multichannel Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Dr. Soqrat Faghihzadeh

    2001-05-01

    Full Text Available Methods and Materials: Investigation of electrically evoked auditory brain stem response (EABR is a new issue, especially in implanted patients. Experiments were performed in C.I Center of Iranian Institute for Science and research expansion,1996 on 30 implanted patients with 22 spectra and MSP cochlear implant system and 30 normal subjects with the range of 3-33 years. Findings: I- EABR was obtained in the implanted patients. 2- Absolute latency of EABR waves is 1-1.5 ms shorter than ABR waves ‘P<0.05. 3-Absolute latency of wave V decreases as a function of electric stimulus magnitude (P<0.05. 4- No significant difference was observed in IPL Ill-V between ABR and EABR.

  18. EEG and brainstem auditory evoked response potentials in adult male drug abusers with self-reported histories of aggressive behavior.

    Science.gov (United States)

    Fishbein, D H; Herning, R I; Pickworth, W B; Haertzen, C A; Hickey, J E; Jaffe, J H

    1989-10-01

    Auditory brainstem evoked response (BAER) and spontaneous electroencephalogram (EEG) were measured in 124 adult male drug abusers. We examined the relationships among psychiatric diagnoses, paper and pencil measures of aggression and hostility, and electrophysiological features. Subjects meeting criteria for antisocial personality disorder (ASP), as defined by DSM-III, were not significantly different from non-ASP subjects for either BAER or spontaneous EEG measures. The more overtly aggressive subjects had significant delays in BAER latency. Aggressive subjects also had more delta activity and less alpha activity in the spontaneous EEG, as have been observed in "psychopaths" and "criminals." Although ASP and aggression are related, these data indicate that aggressiveness may be a separate, albeit overlapping, trait. As both early aggression and a diagnosis of ASP are predictors of later drug use, the findings that only aggression was associated with EEG slowing and brainstem delays may indicate that ASP and aggression make independent contributions to vulnerability to the development of drug abuse.

  19. An objective method for measuring face detection thresholds using the sweep steady-state visual evoked response.

    Science.gov (United States)

    Ales, Justin M; Farzin, Faraz; Rossion, Bruno; Norcia, Anthony M

    2012-09-29

    We introduce a sensitive method for measuring face detection thresholds rapidly, objectively, and independently of low-level visual cues. The method is based on the swept parameter steady-state visual evoked potential (ssVEP), in which a stimulus is presented at a specific temporal frequency while parametrically varying ("sweeping") the detectability of the stimulus. Here, the visibility of a face image was increased by progressive derandomization of the phase spectra of the image in a series of equally spaced steps. Alternations between face and fully randomized images at a constant rate (3/s) elicit a robust first harmonic response at 3 Hz specific to the structure of the face. High-density EEG was recorded from 10 human adult participants, who were asked to respond with a button-press as soon as they detected a face. The majority of participants produced an evoked response at the first harmonic (3 Hz) that emerged abruptly between 30% and 35% phase-coherence of the face, which was most prominent on right occipito-temporal sites. Thresholds for face detection were estimated reliably in single participants from 15 trials, or on each of the 15 individual face trials. The ssVEP-derived thresholds correlated with the concurrently measured perceptual face detection thresholds. This first application of the sweep VEP approach to high-level vision provides a sensitive and objective method that could be used to measure and compare visual perception thresholds for various object shapes and levels of categorization in different human populations, including infants and individuals with developmental delay.

  20. Mathematical impairment associated with high-contrast abnormalities in change detection and magnocellular visual evoked response.

    Science.gov (United States)

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

    2015-10-01

    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.

  1. Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle

    National Research Council Canada - National Science Library

    Mang, Daniel Wh; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2014-01-01

    Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury...

  2. A mucosal IgA response, but no systemic antibody response, is evoked by intranasal immunisation of dogs with Echinococcus granulosus surface antigens iscoms.

    Science.gov (United States)

    Carol, H; Nieto, A

    1998-09-16

    The search for protective antigens of intestinal parasites is conditioned by the methodology used to induce a relevant local immune response against them. The present work describes the use of immuno stimulating complexes (iscoms) from tegumental antigens from protoscoleces (PSC) of the cestode Echinococcus granulosus as immunogens in dogs by the intranasal route. It also describes the evaluation of the immune response evoked at the antibody level (systemically and at a distant mucosal location) as well as at the level of antibody secreting cells in peripheral blood. Iscoms from both E. granulosus tegumental antigens and hen ovalbumin (OVA), given at 50 microg doses by intranasal route, evoked significant secretory IgA antibody responses detected in saliva. Specific IgA secreting cells in peripheral blood also increased 10-20-fold, although transiently, after primary and secondary stimulation, whereas specific IgG secreting cells in peripheral blood were only detected in some individuals after the second antigenic exposure. Generation of immune responses at a related mucosal site provides evidence of localised immunity. No significant increase in systemic antibody titers of either IgM, IgG or IgA isotype was detected in plasma as a result of the immunisation. This fact could reflect that the nasopharyngeal mucosal associated lymphoid tissue of dogs is more strictly compartmentalised than that of other mammals.

  3. Topology Optimization for Minimizing the Resonant Response of Plates with Constrained Layer Damping Treatment

    Directory of Open Access Journals (Sweden)

    Zhanpeng Fang

    2015-01-01

    Full Text Available A topology optimization method is proposed to minimize the resonant response of plates with constrained layer damping (CLD treatment under specified broadband harmonic excitations. The topology optimization problem is formulated and the square of displacement resonant response in frequency domain at the specified point is considered as the objective function. Two sensitivity analysis methods are investigated and discussed. The derivative of modal damp ratio is not considered in the conventional sensitivity analysis method. An improved sensitivity analysis method considering the derivative of modal damp ratio is developed to improve the computational accuracy of the sensitivity. The evolutionary structural optimization (ESO method is used to search the optimal layout of CLD material on plates. Numerical examples and experimental results show that the optimal layout of CLD treatment on the plate from the proposed topology optimization using the conventional sensitivity analysis or the improved sensitivity analysis can reduce the displacement resonant response. However, the optimization method using the improved sensitivity analysis can produce a higher modal damping ratio than that using the conventional sensitivity analysis and develop a smaller displacement resonant response.

  4. Experience with Sugar Modifies Behavioral but not Taste-Evoked Medullary Responses to Sweeteners in Mice

    Science.gov (United States)

    2013-01-01

    Dietary exposure to sugars increases the preference for and intake of sugar solutions in mice. We used brief-access lick tests and multiunit electrophysiological recordings from the nucleus of the solitary tract (NST) to investigate the role of taste in diet-induced changes in sucrose responsiveness. We exposed C57BL/6J (B6) and 129X1/SvJ (129) mice to either a sucrose diet (chow, water, and a 500mM sucrose solution) or a control diet (chow and water) for 3 days. In B6 mice, exposure to the sucrose diet decreased the appetitive response (i.e., number of trials initiated) but had no effect on the consummatory response (i.e., rate of licking) to 500mM sucrose and 20mM saccharin. In 129 mice, exposure to the sucrose diet increased the appetitive response but had no effect on the consummatory response to the sweetener solutions. In the NST recordings, the B6 mice exhibited larger multiunit responses to sweeteners than 129 mice, but there was no effect of the sucrose diet in either strain. Our results indicate that sucrose exposure alters the appetitive response of B6 and 129 mice to sweeteners in diametrically opposed ways and that these changes are mediated by structures in the gustatory neuraxis above the NST (e.g., ventral forebrain). PMID:24084168

  5. 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

    2015-01-01

    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 m......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...

  6. The effect of boric acid on acethylcholine, bethanechol and potasssium-evoked responses on ileum of rat.

    Science.gov (United States)

    Ince, S; Turkmen, R; Yavuz, H

    2011-01-01

    1 The aim of this study was to clarify the effect of boric acid on contractions of rat isolated ileum. 2 Contractile responses expressed as Emax and pD2 for acetylcholine (10(-3)-10(-8) m, Ach), bethanechol (10(-3)-10(-8) m) and potassium (10-80 × 10(-3) m, KCl) were determined in the absence and presence of boric acid (10(-3); 5 × 10(-4); 10(-4) m). 3 The contractile response to Ach in the presence of verapamil (10(-6) or 10(-8) m) or in calcium-free Tyrode's solution was also determined in the absence and presence of boric acid. 4 Boric acid did not affect the contractile response to Ach, bethanechol or KCl. Single or cumulative treatment of boric acid did not affect ileum muscle contraction evoked by KCl. The atropine-resistant component of Ach-induced contraction and 4-diphenyl-acetoxy-N-methyl-piperidine methiodide-resistant component of bethanechol-induced contraction were not inhibited by boric acid (10(-3) m). The contractile response to Ach was reduced in calcium-free Tyrode's solution, and the contractile response was not affected by (10(-8) m). The addition of boric acid (10(-3) m) in combination with verapamil (10(-8) m) did not significantly affect the contractile response to Ach. 5 In conclusion, boric acid does not affect contractions induced by Ach, bethanechol or potassium in rat isolated ileum. © 2011 Blackwell Publishing Ltd.

  7. 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.|info:eu-repo/dai/nl/304828750

    2009-01-01

    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

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

    NARCIS (Netherlands)

    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.

    2005-01-01

    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

  9. Evoked acoustic emission

    DEFF Research Database (Denmark)

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

    1985-01-01

    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...

  10. AT1 and AT2 Receptors in the Prelimbic Cortex Modulate the Cardiovascular Response Evoked by Acute Exposure to Restraint Stress in Rats.

    Science.gov (United States)

    Brasil, Taíz F S; Fassini, Aline; Corrêa, Fernando M

    2017-07-10

    The prelimbic cortex (PL) is an important structure in the neural pathway integrating stress responses. Brain angiotensin is involved in cardiovascular control and modulation of stress responses. Blockade of angiotensin receptors has been reported to reduce stress responses. Acute restraint stress (ARS) is a stress model, which evokes sustained blood pressure increase, tachycardia, and reduction in tail temperature. We therefore hypothesized that PL locally generated angiotensin and angiotensin receptors modulate stress autonomic responses. To test this hypothesis, we microinjected an angiotensin-converting enzyme (ACE) inhibitor or angiotensin antagonists into the PL, prior to ARS. Male Wistar rats were used; guide cannulas were bilaterally implanted in the PL for microinjection of vehicle or drugs. A polyethylene catheter was introduced into the femoral artery to record cardiovascular parameters. Tail temperature was measured using a thermal camera. ARS was started 10 min after PL treatment with drugs. Pretreatment with ACE inhibitor lisinopril (0.5 nmol/100 nL) reduced the pressor response, but did not affect ARS-evoked tachycardia. At a dose of 1 nmol/100 nL, it reduced both ARS pressor and tachycardic responses. Pretreatment with candesartan, AT1 receptor antagonist reduced ARS-evoked pressor response, but not tachycardia. Pretreatment with PD123177, AT2 receptor antagonist, reduced tachycardia, but did not affect ARS pressor response. No treatment affected ARS fall in tail temperature. Results suggest involvement of PL angiotensin in the mediation of ARS cardiovascular responses, with participation of both AT1 and AT2 receptors. In conclusion, results indicate that PL AT1-receptors modulate the ARS-evoked pressor response, while AT2-receptors modulate the tachycardic component of the autonomic response.

  11. Low-frequency stimulation of group III and IV hind limb afferents evokes reflex pressor responses in decerebrate rats.

    Science.gov (United States)

    Harms, Jonathan E; Copp, Steven W; Kaufman, Marc P

    2016-10-01

    Contraction of freely perfused hind limb muscles in decerebrate rats evokes the exercise pressor reflex, resulting in sympathetic activation and increased blood pressure. This reflex is propagated along mechanically sensitive group III and metabolically sensitive group IV afferent nerve fibers. Recent research by our laboratory has focused on the exaggeration of the exercise pressor reflex in decerebrate rats with simulated peripheral artery disease, which was induced by ligating the femoral artery for 72 h before the start of the experiment. Recently, we showed that ligating the femoral artery increased the responses of single fiber group III and IV triceps surae muscle afferents to static contraction. The objective of this study was to determine if electrical stimulation of group III and IV afferents at frequencies approximating those occurring during static contraction was capable of reflexively increasing arterial blood pressure. We directly stimulated muscle afferents in the absence of muscle contraction for both freely perfused and ligated rats. We established 0.25 Hz as the minimal stimulation frequency to observe a sustained blood pressure response. The blood pressure response increased in a graded fashion as both stimulus frequency and motor threshold were increased. Additionally, we observed similar blood pressure responses from both freely perfused and ligated rats, suggesting that spinal and medullary processing of group III and IV afferent input plays no role in augmenting the pressor response to contraction caused by femoral artery ligation. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  12. Electroencephalographic evoked pain response is suppressed by spinal cord stimulation in complex regional pain syndrome: a case report.

    Science.gov (United States)

    Hylands-White, Nicholas; Duarte, Rui V; Beeson, Paul; Mayhew, Stephen D; Raphael, Jon H

    2016-12-01

    Pain is a subjective response that limits assessment. The purpose of this case report was to explore how the objectivity of the electroencephalographic response to thermal stimuli would be affected by concurrent spinal cord stimulation. A patient had been implanted with a spinal cord stimulator for the management of complex regional pain syndrome of both hands for 8 years. Following ethical approval and written informed consent we induced thermal stimuli using the Medoc PATHWAY Pain & Sensory Evaluation System on the right hand of the patient with the spinal cord stimulator switched off and with the spinal cord stimulator switched on. The patient reported a clinically significant reduction in thermal induced pain using the numerical rating scale (71.4 % reduction) with spinal cord stimulator switched on. Analysis of electroencephalogram recordings indicated the occurrence of contact heat evoked potentials (N2-P2) with spinal cord stimulator off, but not with spinal cord stimulator on. This case report suggests that thermal pain can be reduced in complex regional pain syndrome patients with the use of spinal cord stimulation and offers objective validation of the reported outcomes with this treatment.

  13. Sex-Specific Automatic Responses to Infant Cries: TMS Reveals Greater Excitability in Females than Males in Motor Evoked Potentials.

    Science.gov (United States)

    Messina, Irene; Cattaneo, Luigi; Venuti, Paola; de Pisapia, Nicola; Serra, Mauro; Esposito, Gianluca; Rigo, Paola; Farneti, Alessandra; Bornstein, Marc H

    2015-01-01

    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 after 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 infant cry specific to females and to the ID1 muscle. We regard this modulation as a response to natural cry sounds because it was attenuated to stimuli increasingly different from natural cry and 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 response 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.

  14. Potential contamination effects of neuronal refractoriness on the speech-evoked mismatch negativity response.

    Science.gov (United States)

    Cranford, Jerry L; Walker, Letitia J; Stuart, Andrew; Elangovan, Saravanan; Pravica, David

    2003-07-01

    The mismatch negativity response (MMN) is an event-related potential that is believed to reflect the automatic (possibly preconscious) neural processing of changes in ongoing environmental sounds. The MMN involves a negative voltage shift of baseline electroencephalographic (EEG) activity in the approximate latency window of the N1 and P2 cortical potentials in response to new or novel sounds. The most commonly used laboratory tests for extracting the MMN from EEG activity all involve oddball stimulus presentation procedures in which the interstimulus intervals (ISIs) of the frequently occurring standard sounds are shorter in length then that of the infrequently occurring deviant sounds. This presents the possibility that the MMN response could be affected by neuronal refractory or recovery events. The present study tested 12 young females, using the syllabic events /da/ and /ga/ as standard and deviant stimuli, and found evidence that, with certain experimental protocols, ISI-dependent neural refractory effects can affect the morphology of the MMN, possibly resulting in misinterpretation of the underlying neural bases of the response.

  15. Changes in Sensory Evoked Responses Coincide with Rapid Improvement in Speech Identification Performance

    Science.gov (United States)

    Alain, Claude; Campeanu, Sandra; Tremblay, Kelly

    2010-01-01

    Perceptual learning is sometimes characterized by rapid improvements in performance within the first hour of training (fast perceptual learning), which may be accompanied by changes in sensory and/or response pathways. Here, we report rapid physiological changes in the human auditory system that coincide with learning during a 1-hour test session…

  16. Differential effects of nitrous oxide and propofol on myogenic transcranial motor evoked responses during sufentanil anaesthesia

    NARCIS (Netherlands)

    Ubags, L. H.; Kalkman, C. J.; Been, H. D.; Drummond, J. C.

    1997-01-01

    We have compared the effects of 50% nitrous oxide and propofol, each administered concurrently with sufentanil, on the amplitudes and latencies of the compound muscle action potential (CMAP) response to transcranial electrical stimulation. Using a crossover design, 12 patients undergoing spinal

  17. 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

    2014-01-01

    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...

  18. Low-frequency versus high-frequency synchronisation in chirp-evoked auditory brainstem responses

    DEFF Research Database (Denmark)

    Rønne, Filip Munch; Gøtsche-Rasmussen, Kristian

    2011-01-01

    This study investigates the frequency specific contribution to the auditory brainstem response (ABR) of chirp stimuli. Frequency rising chirps were designed to compensate for the cochlear traveling wave delay, and lead to larger wave-V amplitudes than for click stimuli as more auditory nerve fibres...

  19. Modeling paternal attentiveness: distressed pups evoke differential neurobiological and behavioral responses in paternal and nonpaternal mice.

    Science.gov (United States)

    Lambert, K G; Franssen, C L; Hampton, J E; Rzucidlo, A M; Hyer, M M; True, M; Kaufman, C; Bardi, M

    2013-03-27

    With the exception of parturition and lactation, male California deer mice (Peromyscus californicus) exhibit the same parental responses toward offspring as conspecific females. A closely related species, Peromyscus maniculatus, however, rarely exhibits paternal responses. In the current study, a comparative species approach was used to assess paternal responses in both Peromyscus species with varying levels of paternal experience (biological fathers, pup-exposed virgins, and pup-naïve virgins). Of special interest was the persistence of the males to direct their attention toward a distressed pup housed in a small enclosure (i.e., a barrier existed between males and pups). In addition to pup-directed responses, non-pup-directed responses such as grooming, resting and jumping were recorded. Subsequently, all animals' brains were assessed for fos-immunoreactivity (ir) in several areas previously associated with the paternal brain circuit. Overall, P. californicus exhibited more pup-directed responses as well as less fos-ir in brain areas involved in emotional integration and processing such as the insula and anterior cingulate. In addition to increased activation of emotional regulatory areas, P. maniculatus males, observed to direct their behavior away from the pup, exhibited higher fos-ir in the nucleus accumbens (involved in goal acquisition), perhaps due to a heightened motivation to avoid the pups. Interestingly, experience with pups altered the lateral septum and amygdala activation of P. maniculatus to levels similar to P. californicus biological fathers. Finally, fos-ir was increased in the medial preoptic area, involved in the maintenance of maternal behavior, in the biological fathers of both species. Thus, although biological predispositions toward pup-directed behaviors were observed in P. californicus males, evidence of a few shifts toward the paternal neural activation profile was apparent in P. maniculatus males. Specifically, modifications in fear

  20. Assessing ecological responses of wolves to wind power plants in Portugal: methodological constrains and conservation implications

    Energy Technology Data Exchange (ETDEWEB)

    Alvaras, Francisco; Rio-Maior, Helena; Roque, Sara; Nakamura, Monia; Cadete, Duarte; Pinto, Sara; Petrucci-Fonseca, Francisco

    2011-07-01

    Full text: Wind-power development has substantially increased in the last decade in Portugal and associated structures mostly overlap with wolf range, which raises major conservation concerns as a potential source of disturbance to this endangered carnivore. However, a comprehensive evaluation is greatly hampered by difficulties in studying wolf ecology and current lack of knowledge on the impacts of wind energy development on non-flying animals, especially large mammals. A research program was initiated in 2006, to: i) establish a methodological protocol for assessing impacts and monitoring wolf ecological responses to wind farms; ii) evaluate potential effects of wind farms on wolf space use and reproduction; iii) apply efficient mitigation and compensation measures. Field methods are based on howling and sign surveys, scat quantification through abundance indices and GPS telemetry. Preliminary results demonstrate that: i) road network built for wind-power development lead to a considerable increase in traffic, especially during construction of wind farms; ii) wolves continue to use areas with wind farms; iii) wolf presence tends to decrease with the cumulative number of turbines; iv) spatial responses of wolves to wind farms appear to depend on the number and proximity of turbines to important pack home sites and prey availability; v) wolves abandon or do not regularly use breeding sites located in the proximity of wind turbines; vi) wolves select breeding places at a lower altitude after wind farm construction, as a response to related disturbance in mountain ridges. Wind farms induce important changes in wolf space use, selection of and fidelity to reproduction sites and reproductive success. These behavioural and spatial responses may constrain connectivity within and between pack territories and increase reproductive instability, especially in already highly humanized landscapes as Portugal. Based on these findings, several preventive mitigation measures

  1. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

    OpenAIRE

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon; Chung, Jin Mo

    2011-01-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compr...

  2. PET measured evoked cerebral blood flow responses in an awake monkey

    Energy Technology Data Exchange (ETDEWEB)

    Perlmutter, J.S.; Lich, L.L.; Margenau, W.; Buchholz, S. (Washington Univ. School of Medicine, St. Louis, MO (USA))

    1991-03-01

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Long-Term Evolution of Brainstem Electrical Evoked Responses to Sound after Restricted Ablation of the Auditory Cortex

    Science.gov (United States)

    Lamas, Verónica; Alvarado, Juan C.; Carro, Juan; Merchán, Miguel A.

    2013-01-01

    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. PMID:24066057

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Linear combination of auditory steady-state responses evoked by co-modulated tones

    DEFF Research Database (Denmark)

    Guérit, François; Marozeau, Jeremy; Epp, Bastian

    2017-01-01

    Up to medium intensities and in the 80–100-Hz region, the auditory steady-state response (ASSR) to a multi-tone carrier is commonly considered to be a linear sum of the dipoles from each tone specific ASSR generator. Here, this hypothesis was investigated when a unique modulation frequency is used...... for all carrier components. Listeners were presented with a co-modulated dual-frequency carrier (1 and 4 kHz), from which the modulator starting phase Ui of the 1-kHz component was systematically varied. The results support the hypothesis of a linear superposition of the dipoles originating from different...

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

    Directory of Open Access Journals (Sweden)

    Marijn Van Dongen

    2015-03-01

    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.

  8. Thujone exhibits low affinity for cannabinoid receptors but fails to evoke cannabimimetic responses.

    Science.gov (United States)

    Meschler, J P; Howlett, A C

    1999-03-01

    Absinthe, an abused drug in the early 1900s, has been speculated to activate the receptors responsible for marijuana intoxication (the CB1 cannabinoid receptor) (Nature 253:365-356; 1975). To test this hypothesis, we investigated oil of wormwood (Artemisia absinthium) the active plant product found in absinthe, and thujone, the active compound found in oil of wormwood. Radioligand receptor binding assays employing membrane preparations from rat brains containing CB1 cannabinoid receptors, and human tonsils containing CB2 receptors, demonstrated that thujone displaced [3H]CP55940, a cannabinoid agonist, only at concentrations above 10 microM. HPLC analysis of oil of wormwood revealed that only the fractions having mobility close to thujone displaced [3H]CP55940 from the CB1 cannabinoid receptor. [35S]GTPgammaS binding assays revealed that thujone failed to stimulate G-proteins even at 0.1 mM. Thujone failed to inhibit forskolin-stimulated adenylate cyclase activity in N18TG2 membranes at 1 mM. Rats administered thujone exhibited different behavioral characteristics compared with rats administered a potent cannabinoid agonist, levonantradol. Therefore, the hypothesis that activation of cannabinoid receptors is responsible for the intoxicating effects of thujone is not supported by the present data.

  9. Using click-evoked auditory brainstem response thresholds in infants to estimate the corresponding pure-tone audiometry thresholds in children referred from UNHS.

    Science.gov (United States)

    Lu, Tsun-Min; Wu, Fang-Wei; Chang, Hsiuwen; Lin, Hung-Ching

    2017-04-01

    To examine whether behavioral pure-tone audiometry (PTA) thresholds in children can be accurately estimated from the corresponding infants' click-evoked auditory brainstem response (ABR) thresholds through a retrospective review of data from a universal newborn hearing screening (UNHS) program in Taiwan. According to medical records from Mackay Memorial Hospital, Taipei Hospital District, 45,450 newborns received hearing screening during January 1999-December 2011. Among these newborns, 104 (82, both ears; 22, one ear; total, 186 ears) received regular follow-up and were recruited as subjects. The relationship between infant click-evoked ABR thresholds and the corresponding child PTA thresholds was determined through Pearson correlation coefficient and linear regression analyses. The correlation coefficient between click-evoked ABR thresholds and behavioral PTA thresholds at the average of frequencies of 1-4 and 2-4 kHz was 0.76 and 0.76, respectively. Linear regression analysis showed that behavioral audiometry thresholds at the average of frequencies of 1-4 and 2-4 kHz were accurately estimated from click-evoked ABR thresholds in 57% and 58% children, respectively. Click-evoked ABR testing is a reliable tool to cautiously estimate behavioral PTA thresholds at the average of frequencies of 1-4 and 2-4 kHz. For accurately performing hearing aid fitting and auditory rehabilitation in congenitally deaf infants, a combination of frequency-specific tone-burst ABR and click-evoked ABR should be used. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Taste-Evoked Responses to Sweeteners in the Nucleus of the Solitary Tract Differ between C57BL/6ByJ and 129P3/J Mice

    Science.gov (United States)

    McCaughey, Stuart A.

    2008-01-01

    C57BL/6ByJ (B6) and 129P3/J (129) mice have different alleles of Tas1r3, which is thought to influence gustatory transduction of sweeteners, but studies have provided conflicting results regarding differences in sweetness perception between these strains. Single-unit taste-evoked activity was measured in the nucleus of the solitary tract (NST) in anesthetized B6 and 129 mice to address this controversy and to provide the first electrophysiological characterization of this nucleus in mice. Neurons had properties similar to those of NST cells in other species, including mean breadth-of-tuning of 0.8 ± 0.0. There were no strain differences in neural responses at 600 or 900 ms after onset, but, with a 5 s evoked period, responses to the sweeteners sucrose, maltose, acesulfame-K, SC-45647, and D-phenylalanine were significantly larger in B6 relative to 129 mice. The strains did not differ in their mean response to NaSaccharin, but it evoked an across-neuron pattern of activity that was more similar to that of sucrose and less similar to that of NaCl in B6 mice compared with 129 mice. Neurons were classified as sucrose, NaCl, or HCl responsive, with the former more common in B6 than 129 mice. Relative to other neurons, sucrose-responsive cells had delayed but more sustained sweetener responses in both strains. The results suggest that B6 mice perceive some sweeteners as more intense, but NaSaccharin as sweeter and less salty, relative to 129 mice. Furthermore, activity evoked by sweeteners includes a phasic response sent to different NST cells than a later tonic response, and only the latter differs between B6 and 129 mice. PMID:17202470

  11. Cellular responses evoked by different surface characteristics of intraosseous titanium implants.

    Science.gov (United States)

    Feller, Liviu; Jadwat, Yusuf; Khammissa, Razia A G; Meyerov, Robin; Schechter, Israel; Lemmer, Johan

    2015-01-01

    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.

  12. Evaluation of deafness in American Paint Horses by phenotype, brainstem auditory-evoked responses, and endothelin receptor B genotype.

    Science.gov (United States)

    Magdesian, K Gary; Williams, D Colette; Aleman, Monica; Lecouteur, Richard A; Madigan, John E

    2009-11-15

    To evaluate deafness in American Paint Horses by phenotype, clinical findings, brainstem auditory-evoked responses (BAERs), and endothelin B receptor (EDNBR) genotype. Case series and case-control studies. 14 deaf American Paint Horses, 20 suspected-deaf American Paint Horses, and 13 nondeaf American Paint Horses and Pintos. Horses were categorized on the basis of coat color pattern and eye color. Testing for the EDNBR gene mutation (associated with overo lethal white foal syndrome) and BAERs was performed. Additional clinical findings were obtained from medical records. All 14 deaf horses had loss of all BAER waveforms consistent with complete deafness. Most horses had the splashed white or splashed white-frame blend coat pattern. Other patterns included frame overo and tovero. All of the deaf horses had extensive head and limb white markings, although the amount of white on the neck and trunk varied widely. All horses had at least 1 partially heterochromic iris, and most had 2 blue eyes. Ninety-one percent (31/34) of deaf and suspected-deaf horses had the EDNBR gene mutation. Deaf and suspected-deaf horses were used successfully for various performance events. All nondeaf horses had unremarkable BAER results. Veterinarians should be aware of deafness among American Paint Horses, particularly those with a splashed white or frame overo coat color pattern, blend of these patterns, or tovero pattern. Horses with extensive head and limb markings and those with blue eyes appeared to be at particular risk.

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

    Directory of Open Access Journals (Sweden)

    Niels Trusbak Haumann

    2016-01-01

    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.

  14. Can subject-specific single-fibre electrically evoked auditory brainstem response data be predicted from a model?

    Science.gov (United States)

    Malherbe, Tiaan K; Hanekom, Tania; Hanekom, Johan J

    2013-07-01

    This article investigates whether prediction of subject-specific physiological data is viable through an individualised computational model of a cochlear implant. Subject-specific predictions could be particularly useful to assess and quantify the peripheral factors that cause inter-subject variations in perception. The results of such model predictions could potentially be translated to clinical application through optimisation of mapping parameters for individual users, since parameters that affect perception would be reflected in the model structure and parameters. A method to create a subject-specific computational model of a guinea pig with a cochlear implant is presented. The objectives of the study are to develop a method to construct subject-specific models considering translation of the method to in vivo human models and to assess the effectiveness of subject-specific models to predict peripheral neural excitation on subject level. Neural excitation patterns predicted by the model are compared with single-fibre electrically evoked auditory brainstem responses obtained from the inferior colliculus in the same animal. Results indicate that the model can predict threshold frequency location, spatial spread of bipolar and tripolar stimulation and electrode thresholds relative to one another where electrodes are located in different cochlear structures. Absolute thresholds and spatial spread using monopolar stimulation are not predicted accurately. Improvements to the model should address this. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  15. Sensorineural hearing loss among cerebellopontine-angle tumor patients examined with pure tone audiometry and brainstem-evoked response audiometry

    Science.gov (United States)

    Rinindra, A. M.; Zizlavsky, S.; Bashiruddin, J.; Aman, R. A.; Wulani, V.; Bardosono, S.

    2017-08-01

    Tumor in the cerebellopontine angle (CPA) accurs for approximately 5-10% of all intracranial tumors, where unilateral hearing loss and tinnitus are the most frequent symptoms. This study aimed to collect data on sensorineural hearing loss in CPA tumor patients in Dr. Cipto Mangunkusumo Hospital (CMH) using pure tone audiometry and brainstem-evoked response audiometry (BERA). It also aimed to obtaine data on CPA-tumor imaging through magnetic resonance imaging (MRI). This was a descriptive, analytic, and cross-sectional study. The subjects of this study were gathered using a total sampling method from secondary data between July 2012 and November 2016. From 104 patients, 30 matched the inclusion criteria. The CPA-tumor patients in the ENT CMH outpatient clinic were mostly female, middle-aged patients (41-60 years) whose clinical presentation was mostly tinnitus and severe, asymmetric sensorineural hearing loss in 10 subjects. From 30 subjects, 29 showed ipsilaterally impaired BERA results, and 17 subjects showed contralaterally impaired BERA results. There were 24 subjects who with large-sized tumors and 19 subjects who had intracanal tumors that had spread until they were extracanal in 19 subjects.

  16. Effect of middle ear effusion on the brain-stem auditory evoked response of Cavalier King Charles Spaniels.

    Science.gov (United States)

    Harcourt-Brown, Thomas R; Parker, John E; Granger, Nicolas; Jeffery, Nick D

    2011-06-01

    Brain-stem auditory evoked responses (BAER) were assessed in 23 Cavalier King Charles Spaniels with and without middle ear effusion at sound intensities ranging from 10 to 100 dB nHL. Significant differences were found between the median BAER threshold for ears where effusions were present (60 dB nHL), compared to those without (30 dB nHL) (P=0.001). The slopes of latency-intensity functions from both groups did not differ, but the y-axis intercept when the x value was zero was greater in dogs with effusions (P=0.009), consistent with conductive hearing loss. Analysis of latency-intensity functions suggested the degree of hearing loss due to middle ear effusion was 21 dB (95% confidence between 10 and 33 dB). Waves I-V inter-wave latency at 90 dB nHL was not significantly different between the two groups. These findings demonstrate that middle ear effusion is associated with a conductive hearing loss of 10-33 dB in affected dogs despite the fact that all animals studied were considered to have normal hearing by their owners. Copyright © 2010. Published by Elsevier Ltd.

  17. Both Ox1R and Ox2R orexin receptors contribute to the cardiorespiratory response evoked from the perifornical hypothalamus.

    Science.gov (United States)

    Beig, Mirza I; Horiuchi, Jouji; Dampney, Roger A L; Carrive, Pascal

    2015-10-01

    Orexin/hypocretin neurons are located in and around the perifornical hypothalamus. Disinhibition of this area in the anaesthetized preparation evokes cardiorespiratory changes that can be reduced to nearly half or more by systemic Almorexant, a dual receptor antagonist of the two known orexin receptors, Ox1R and Ox2R. It is not clear if these reductions result from the blockade of one receptor or both. To determine the contribution of the two receptors, we compared the effects of Almorexant to those of the selective Ox1R antagonist ACT335827 and the selective Ox2R antagonists EMPA and TCS-OX2-29. Bicuculline (20 pmol) was injected in the perifornical hypothalamus of urethane-anaesthetized rats before and after administration of the drugs (all 15 mg/kg, intravenously). The pressor, tachycardic and tachypneic responses to bicuculline were attenuated/reduced by ACT335827 (by 19%, ns; 10%, ns and 24%, P hypothalamus under anaesthesia. They are consistent with our previous study in the conscious animal. © 2015 Wiley Publishing Asia Pty Ltd.

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

    Directory of Open Access Journals (Sweden)

    Irene eMessina

    2016-01-01

    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.

  19. Predictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma.

    Science.gov (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

    2012-03-01

    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.

  20. Steady-state visual evoked potentials can be explained by temporal superposition of transient event-related responses.

    Directory of Open Access Journals (Sweden)

    Almudena Capilla

    Full Text Available BACKGROUND: One common criterion for classifying electrophysiological brain responses is based on the distinction between transient (i.e. event-related potentials, ERPs and steady-state responses (SSRs. The generation of SSRs is usually attributed to the entrainment of a neural rhythm driven by the stimulus train. However, a more parsimonious account suggests that SSRs might result from the linear addition of the transient responses elicited by each stimulus. This study aimed to investigate this possibility. METHODOLOGY/PRINCIPAL FINDINGS: We recorded brain potentials elicited by a checkerboard stimulus reversing at different rates. We modeled SSRs by sequentially shifting and linearly adding rate-specific ERPs. Our results show a strong resemblance between recorded and synthetic SSRs, supporting the superposition hypothesis. Furthermore, we did not find evidence of entrainment of a neural oscillation at the stimulation frequency. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that visual SSRs can be explained as a superposition of transient ERPs. These findings have critical implications in our current understanding of brain oscillations. Contrary to the idea that neural networks can be tuned to a wide range of frequencies, our findings rather suggest that the oscillatory response of a given neural network is constrained within its natural frequency range.

  1. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats.

    Science.gov (United States)

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon; Chung, Jin Mo

    2011-05-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compression were recorded from the lumbar spinal cord using an in vivo extracellular single unit recording setup 1 day after ankle sprain. EA was applied to the SI-6 acupoint on the right forelimb (contralateral to the sprained ankle) by trains of electrical pulses (10 Hz, 1-ms pulse width, 2-mA intensity) for 30 min. After EA, WBR of the sprained foot significantly recovered and dorsal horn neuron activities were significantly suppressed in ankle-sprained rats. However, EA produced no effect in normal rats. The inhibitory effect of EA on hyperactivities of dorsal horn neurons of ankle-sprained rats was blocked by the α-adrenoceptor antagonist phentolamine (5 mg/kg ip) but not by the opioid receptor antagonist naltrexone (10 mg/kg ip). These data suggest that EA-induced analgesia in ankle sprain pain is mediated mainly by suppressing dorsal horn neuron activities through α-adrenergic descending inhibitory systems at the spinal level.

  2. Mechanisms of habitual approach: Failure to suppress irrelevant responses evoked by previously reward-associated stimuli.

    Science.gov (United States)

    Anderson, Brian A; Folk, Charles L; Garrison, Rebecca; Rogers, Leeland

    2016-06-01

    Reward learning has a powerful influence on the attention system, causing previously reward-associated stimuli to automatically capture attention. Difficulty ignoring stimuli associated with drug reward has been linked to addiction relapse, and the attention system of drug-dependent patients seems especially influenced by reward history. This and other evidence suggests that value-driven attention has consequences for behavior and decision-making, facilitating a bias to approach and consume the previously reward-associated stimulus even when doing so runs counter to current goals and priorities. Yet, a mechanism linking value-driven attention to behavioral responding and a general approach bias is lacking. Here we show that previously reward-associated stimuli escape inhibitory processing in a go/no-go task. Control experiments confirmed that this value-dependent failure of goal-directed inhibition could not be explained by search history or residual motivation, but depended specifically on the learned association between particular stimuli and reward outcome. When a previously high-value stimulus is encountered, the response codes generated by that stimulus are automatically afforded high priority, bypassing goal-directed cognitive processes involved in suppressing task-irrelevant behavior. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  3. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

    Science.gov (United States)

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

    2011-01-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compression were recorded from the lumbar spinal cord using an in vivo extracellular single unit recording setup 1 day after ankle sprain. EA was applied to the SI-6 acupoint on the right forelimb (contralateral to the sprained ankle) by trains of electrical pulses (10 Hz, 1-ms pulse width, 2-mA intensity) for 30 min. After EA, WBR of the sprained foot significantly recovered and dorsal horn neuron activities were significantly suppressed in ankle-sprained rats. However, EA produced no effect in normal rats. The inhibitory effect of EA on hyperactivities of dorsal horn neurons of ankle-sprained rats was blocked by the α-adrenoceptor antagonist phentolamine (5 mg/kg ip) but not by the opioid receptor antagonist naltrexone (10 mg/kg ip). These data suggest that EA-induced analgesia in ankle sprain pain is mediated mainly by suppressing dorsal horn neuron activities through α-adrenergic descending inhibitory systems at the spinal level. PMID:21389301

  4. Amyloid Form of Ovalbumin Evokes Native Antigen-specific Immune Response in the Host

    Science.gov (United States)

    Tufail, Saba; Owais, Mohammad; Kazmi, Shadab; Balyan, Renu; Kaur Khalsa, Jasneet; Faisal, Syed Mohd.; Sherwani, Mohd. Asif; Gatoo, Manzoor Ahmad; Umar, Mohd. Saad; Zubair, Swaleha

    2015-01-01

    Amyloids are highly organized protein aggregates that arise from inappropriately folded versions of proteins or polypeptides under both physiological as well as simulated ambiences. Once thought to be irreversible assemblies, amyloids have begun to expose their more dynamic and reversible attributes depending upon the intrinsic properties of the precursor protein/peptide and experimental conditions such as temperature, pressure, structural modifications in proteins, or presence of chemicals in the reaction mixture. It has been repeatedly proposed that amyloids undergo transformation to the bioactive peptide/protein forms under specific conditions. In the present study, amyloids assembled from the model protein ovalbumin (OVA) were found to release the precursor protein in a slow and steady manner over an extended time period. Interestingly, the released OVA from amyloid depot was found to exhibit biophysical characteristics of native protein and reacted with native-OVA specific monoclonal as well as polyclonal antibodies. Moreover, antibodies generated upon immunization of OVA amyloidal aggregates or fibrils were found to recognize the native form of OVA. The study suggests that amyloids may act as depots for the native form of the protein and therefore can be exploited as vaccine candidates, where slow antigen release over extended time periods is a pre-requisite for the development of desired immune response. PMID:25512377

  5. Time course and hemispheric lateralization effects of complex pitch processing: evoked magnetic fields in response to rippled noise stimuli.

    Science.gov (United States)

    Hertrich, Ingo; Mathiak, Klaus; Lutzenberger, Werner; Ackermann, Hermann

    2004-01-01

    To delineate the time course and processing stages of pitch encoding at the level of the supratemporal plane, the present study recorded evoked magnetic fields in response to rippled noise (RN) stimuli. RN largely masks simple tonotopic representations and addresses pitch processing within the temporal domain (periodicity encoding). Four dichotic stimulus types (111 or 133 Hz RN at one ear, white noise to the other one) were applied in randomized order during either visual distraction or selective auditory attention. Strictly periodic signals, noise-like events, and mixtures of both signals served as control conditions. (1) Attention-dependent ear x hemisphere interactions were observed within the time domain of the M50 field, indicating early streaming of auditory information. (2) M100 responses to strictly periodic stimuli were found lateralized to the right hemisphere. Furthermore, the higher-pitched stimuli yielded enhanced activation as compared to the lower-pitch signals (pitch scaling), conceivably reflecting sensory memory operations. (3) Besides right-hemisphere pitch scaling, the relatively late M100 component in association with the RN condition (latency = 136 ms) showed significantly stronger field strengths over the left hemisphere. Control experiments revealed this lateralization effect to be related to noise rather than pitch processing. Furthermore, subtle noise variations interacted with signal periodicity. Obviously, thus, complex task demands such as RN encoding give rise to functional segregation of auditory processing across the two hemispheres (left hemisphere: noise, right hemisphere: periodicity representation). The observed noise/periodicity interactions, furthermore, might reflect pitch-synchronous spectral evaluation at the level of the left supratemporal plane, triggered by right-hemisphere representation of signal periodicity. Copyright 2004 Elsevier Ltd.

  6. Trait-like differences in underlying oscillatory state predict individual differences in the TMS-evoked response.

    Science.gov (United States)

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

    2014-01-01

    Combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) can provide insights into how differing cognitive contexts produce different brain states, through TMS-based measures of effective connectivity. For instance, in a recent study, the amplitude of the TMS-evoked response (TMS-ER) derived during the delay-period of a spatial short-term memory (STM) task had a larger amplitude, and greater spread to distal cortical areas, than the TMS-ER from a fixation condition (Johnson et al. J Neurophysiol, 2012). This indicated that the brain's electrical response to TMS is influenced by the cognitive context (STM or fixation) at the time of stimulation. This study also showed significant individual differences in the shape of the TMS-ER. Further, delay-period spectrograms revealed patterns of activity, the sustained pattern of delay-period activity (SPDPA), which were different across individuals. The present study addressed whether individual differences in the SPDPA predict spectral properties of the TMS-ER. We predicted that significant relationships would exist in task-relevant areas, such as the prefrontal cortex in the case of STM. The TMS-ER was derived using TMS-EEG and source-localization methods. The SPDPA varied significantly across subjects, and these differences predicted individual differences in several frequency-dependent parameters of the TMS-ER that were specific to task-relevant areas, including prefrontal cortex for STM. Furthermore, a follow-up test-retest study revealed that the SPDPA was stable over sessions. These observations offer a window into how individual differences in the effects of TMS are related to trait-like individual differences in physiological profile. Published by Elsevier Inc.

  7. 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

    2001-01-01

    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....... 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...

  8. Whole body oxygen uptake and evoked knee torque in response to low frequency electrical stimulation of the quadriceps muscles: V•O2 frequency response to NMES.

    Science.gov (United States)

    Minogue, Conor M; Caulfield, Brian M; Lowery, Madeleine M

    2013-06-28

    There is emerging evidence that isometric Neuromuscular Electrical Stimulation (NMES) may offer a way to elicit therapeutically significant increases in whole-body oxygen uptake in order to deliver aerobic exercise to patients unable to exercise volitionally, with consequent gains in cardiovascular health. The optimal stimulation frequency to elicit a significant and sustained pulmonary oxygen uptake has not been determined. The aim of this study was to examine the frequency response of the oxygen uptake and evoked torque due to NMES of the quadriceps muscles across a range of low frequencies spanning the twitch to tetanus transition. Ten healthy male subjects underwent bilateral NMES of the quadriceps muscles comprising eight 4 minute bouts of intermittent stimulation at selected frequencies in the range 1 to 12 Hz, interspersed with 4 minutes rest periods. Respiratory gases and knee extensor torque were simultaneously monitored throughout. Multiple linear regression was used to fit the resulting data to an energetic model which expressed the energy rate in terms of the pulse frequency, the torque time integral and a factor representing the accumulated force developed per unit time. Additional oxygen uptake increased over the frequency range to a maximum of 564 (SD 114) ml min-1 at 12 Hz, and the respiratory exchange ratio was close to unity from 4 to 12 Hz. While the highest induced torque occurred at 12 Hz, the peak of the force development factor occurred at 6 Hz. The regression model accounted for 88% of the variability in the observed energetic response. Taking into account the requirement to avoid prolonged tetanic contractions and to minimize evoked torque, the results suggest that the ideal frequency for sustainable aerobic exercise is 4 to 5 Hz, which coincided in this study with the frequency above which significant twitch force summation occurred.

  9. Constrained Response Surface Optimisation and Taguchi Methods for Precisely Atomising Spraying Process

    Science.gov (United States)

    Luangpaiboon, P.; Suwankham, Y.; Homrossukon, S.

    2010-10-01

    This research presents a development of a design of experiment technique for quality improvement in automotive manufacturing industrial. The quality of interest is the colour shade, one of the key feature and exterior appearance for the vehicles. With low percentage of first time quality, the manufacturer has spent a lot of cost for repaired works as well as the longer production time. To permanently dissolve such problem, the precisely spraying condition should be optimized. Therefore, this work will apply the full factorial design, the multiple regression, the constrained response surface optimization methods or CRSOM, and Taguchi's method to investigate the significant factors and to determine the optimum factor level in order to improve the quality of paint shop. Firstly, 2κ full factorial was employed to study the effect of five factors including the paint flow rate at robot setting, the paint levelling agent, the paint pigment, the additive slow solvent, and non volatile solid at spraying of atomizing spraying machine. The response values of colour shade at 15 and 45 degrees were measured using spectrophotometer. Then the regression models of colour shade at both degrees were developed from the significant factors affecting each response. Consequently, both regression models were placed into the form of linear programming to maximize the colour shade subjected to 3 main factors including the pigment, the additive solvent and the flow rate. Finally, Taguchi's method was applied to determine the proper level of key variable factors to achieve the mean value target of colour shade. The factor of non volatile solid was found to be one more additional factor at this stage. Consequently, the proper level of all factors from both experiment design methods were used to set a confirmation experiment. It was found that the colour shades, both visual at 15 and 45 angel of measurement degrees of spectrophotometer, were nearly closed to the target and the defective at

  10. 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.

  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

    2012-01-01

    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. 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

    2012-08-01

    Full Text Available 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, which is the ratio between the number of detections and the sum of detections and non-detections. 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. Afterwards, the same speech stimuli were presented at 55, 65, and 75 dB sound pressure level, and CAEPs were recorded. An automatic statistical detection paradigm was used for CAEP detection. 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. 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 might provide 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.

  13. Rhesus macaque model of chronic opiate dependence and neuro-AIDS: longitudinal assessment of auditory brainstem responses and visual evoked potentials.

    Science.gov (United States)

    Riazi, Mariam; Marcario, Joanne K; Samson, Frank K; Kenjale, Himanshu; Adany, Istvan; Staggs, Vincent; Ledford, Emily; Marquis, Janet; Narayan, Opendra; Cheney, Paul D

    2009-06-01

    Our work characterizes the effects of opiate (morphine) dependence on auditory brainstem and visual evoked responses in a rhesus macaque model of neuro-AIDS utilizing a chronic continuous drug delivery paradigm. The goal of this study was to clarify whether morphine is protective, or if it exacerbates simian immunodeficiency virus (SIV)-related systemic and neurological disease. Our model employs a macrophage tropic CD4/CCR5 coreceptor virus, SIV(mac)239 (R71/E17), which crosses the blood-brain barrier shortly after inoculation and closely mimics the natural disease course of human immunodeficiency virus infection. The cohort was divided into three groups: morphine only, SIV only, and SIV + morphine. Evoked potential (EP) abnormalities in subclinically infected macaques were evident as early as 8 weeks postinoculation. Prolongations in EP latencies were observed in SIV-infected macaques across all modalities. Animals with the highest cerebrospinal fluid viral loads and clinical disease showed more abnormalities than those with subclinical disease, confirming our previous work (Raymond et al., J Neurovirol 4:512-520, 1998; J Neurovirol 5:217-231, 1999; AIDS Res Hum Retroviruses 16:1163-1173, 2000). Although some differences were observed in auditory and visual evoked potentials in morphine-treated compared to morphine-untreated SIV-infected animals, the effects were relatively small and not consistent across evoked potential type. However, morphine-treated animals with subclinical disease had a clear tendency toward higher virus loads in peripheral and central nervous system tissues (Marcario et al., J Neuroimmune Pharmacol 3:12-25, 2008) suggesting that if had been possible to follow all animals to end-stage disease, a clearer pattern of evoked potential abnormality might have emerged.

  14. Sex Differences in Orienting to Pictures with and without Humans: Evidence from the Cardiac Evoked Response (ECR) and the Cortical Long Latency Parietal Positivity (LPP)

    Science.gov (United States)

    Althaus, Monika; Groen, Yvonne; van der Schaft, Lutske; Minderaa, Ruud B.; Tucha, Oliver; Mulder, Lambertus J. M.; Wijers, Albertus A.

    2014-01-01

    Objective This study investigated the effect of social relevance in affective pictures on two orienting responses, i.e. the evoked cardiac response (ECR), and a long latency cortical evoked potential (LPP) and whether this effect would differ between males and females. Assuming that orienting to affective social information is fundamental to experiencing affective empathy, associations between self-report measures of empathy and the two orienting responses were investigated. Method ECRs were obtained from 34 female and 30 male students, and LPPs from 25 female and 27 male students viewing 414 pictures from the International Affective Picture System. Pictures portrayed pleasant, unpleasant and neutral scenes with and without humans. Results Both the ECR and LPP showed the largest response to pictures with humans in unpleasant situations. For both measures, the responses to pictures with humans correlated with self-report measures of empathy. While we found a greater male than female responsiveness to the pictures without humans in the ECR, a greater female than male responsiveness was observed in the LPP response to pictures with humans. Conclusion and Significance The sensitivity of these orienting responses to social relevance and their differential contribution to the prediction of individual differences underline the validity of their combined use in clinical studies investigating individuals with social disabilities. PMID:25330003

  15. Emotion responses under evoked consumption contexts: A focus on the consumers’ frequency of product consumption and the stability of responses

    NARCIS (Netherlands)

    Piqueras Fiszman, B.; Jaeger, S.R.

    2014-01-01

    Previous research has demonstrated that the context in which a certain food is consumed (even if imagined) can affect consumers’ associative emotional responses to that product. In three separate studies we extended this line of research by: (1) replicating these previous findings with consumers

  16. Minimal current intensity to elicit an evoked motor response cannot discern between needle-nerve contact and intraneural needle insertion.

    Science.gov (United States)

    Wiesmann, Thomas; Bornträger, Andreas; Vassiliou, Timon; Hadzic, Admir; Wulf, Hinnerk; Müller, Hans-Helge; Steinfeldt, Thorsten

    2014-03-01

    The ability of an evoked motor response (EMR) with nerve stimulation to detect intraneural needle placement reliably at low current intensity has recently been challenged. In this study, we hypothesized that current intensity is higher in needle-nerve contact than in intraneural needle placement. Brachial plexus nerves were exposed surgically in 6 anesthetized pigs. An insulated needle connected to a nerve stimulator was placed either with 1 mm distance to the nerve (control position), adjacent to nerve epineurium (needle-nerve contact position), or inside the nerve (intraneural position). Three pulse duration settings were applied in random fashion (0.1, 0.3, or 1.0 milliseconds) at each needle position. Starting at 0.0 mA, electrical current was increased until a minimal threshold current resulting in a specific EMR was observed. Fifty threshold current measurements were scheduled for each needle position-pulse duration setting. Four hundred-fifty threshold currents in 50 peripheral nerves were measured. Threshold current intensities (mA) to elicit EMR showed small differences between the needle-nerve contact position [median (25th-75th percentiles); 0.1 milliseconds: 0.12 (0.08-0.18) mA; 0.3 milliseconds: 0.10 (0.06-0.12) mA; 1.0 milliseconds: 0.06 (0.04-0.10) mA] and the intraneural position (0.1 milliseconds: 0.12 [0.10-0.16] mA; 0.3 milliseconds: 0.08 [0.06-0.10] mA; 1.0 milliseconds: 0.06 [0.06-0.08] mA) that are neither statistically significant nor clinically relevant. Regardless of the pulse duration that was applied, the 98.33% confidence interval revealed a difference of at most 0.02 mA. However, threshold current intensities to elicit EMR were lower for the needle-nerve contact position than for the control position (0.1 milliseconds: 0.28 [0.26-0.32] mA; 0.3 milliseconds: 0.20 [0.16-0.22] mA; 1.0 milliseconds: 0.12 [0.10-0.14] mA). The confidence interval for differences suggests minimal current intensity to elicit a motor response that cannot

  17. Comparison of Effects of Different Doses Dexmedetomidine on Inhibiting Tracheal Intubation-Evoked Haemodynamic Response in the Elderly Patients

    Science.gov (United States)

    Chang-Ming, Wang; Shuai, Tang; Lin-Lin, Tong; Yu-Feng, Han

    2015-01-01

    doses DEX, the present result showed that 0.5μg/kg DEX had an effective inhibition, without respiratory depression, on tracheal intubation evoked cardiovascular response in the elderly patients. PMID:26500982

  18. Auditory and visual P300 evoked potentials do not predict response to valproate treatment of aggression in patients with borderline and antisocial personality disorders.

    Science.gov (United States)

    Reeves, Roy R; Struve, Frederick A; Patrick, Gloria

    2005-01-01

    In this study of patients with borderline personality disorder (BPD) or antisocial personality disorder (ASPD) hospitalized because of aggressive behavior, auditory and visual P300 evoked potentials were obtained prior to treatment with valproate. Eight ASPD patients (8 males, 0 females) and 11 BPD patients (2 males, 9 females) showed improvement, while in 7 patients with ASPD (7 males, 0 females) and 10 patients with BPD (2 males, 8 females), aggression was not improved. Differences in auditory and visual P300 latencies and amplitudes were not significant for either diagnosis, or for both diagnoses combined. These findings suggest that auditory or visual P300 evoked potentials may not be useful for predicting response of aggressive behavior to valproate treatment in patients with BPD or ASPD.

  19. Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. IV. Responses after spectacle-induced adaptation

    Science.gov (United States)

    Clendaniel, R. A.; Lasker, D. M.; Minor, L. B.; Shelhamer, M. J. (Principal Investigator)

    2001-01-01

    The horizontal angular vestibuloocular reflex (VOR) evoked by sinusoidal rotations from 0.5 to 15 Hz and acceleration steps up to 3,000 degrees /s(2) to 150 degrees /s was studied in six squirrel monkeys following adaptation with x2.2 magnifying and x0.45 minimizing spectacles. For sinusoidal rotations with peak velocities of 20 degrees /s, there were significant changes in gain at all frequencies; however, the greatest gain changes occurred at the lower frequencies. The frequency- and velocity-dependent gain enhancement seen in normal monkeys was accentuated following adaptation to magnifying spectacles and diminished with adaptation to minimizing spectacles. A differential increase in gain for the steps of acceleration was noted after adaptation to the magnifying spectacles. The gain during the acceleration portion, G(A), of a step of acceleration (3,000 degrees /s(2) to 150 degrees /s) increased from preadaptation values of 1.05 +/- 0.08 to 1.96 +/- 0.16, while the gain during the velocity plateau, G(V), only increased from 0.93 +/- 0.04 to 1.36 +/- 0.08. Polynomial fits to the trajectory of the response during the acceleration step revealed a greater increase in the cubic than the linear term following adaptation with the magnifying lenses. Following adaptation to the minimizing lenses, the value of G(A) decreased to 0.61 +/- 0.08, and the value of G(V) decreased to 0.59 +/- 0.09 for the 3,000 degrees /s(2) steps of acceleration. Polynomial fits to the trajectory of the response during the acceleration step revealed that there was a significantly greater reduction in the cubic term than in the linear term following adaptation with the minimizing lenses. These findings indicate that there is greater modification of the nonlinear as compared with the linear component of the VOR with spectacle-induced adaptation. In addition, the latency to the onset of the adapted response varied with the dynamics of the stimulus. The findings were modeled with a bilateral model

  20. Stochastic Security and Risk-Constrained Scheduling for an Autonomous Microgrid with Demand Response and Renewable Energy Resources

    DEFF Research Database (Denmark)

    Vahedipour-Dahraie, Mostafa; Rashidizadeh-Kermani, Homa; Najafi, Hamid Reza

    2017-01-01

    Increasing penetration of intermittent renewable energy sources (RESs) and the development of advanced information, give rise to questions on how responsive loads can be managed to optimize the use of resources and assets. In this context, demand response (DR) as a way for modifying the consumption...... is to determine the optimal scheduling with considering risk aversion and system frequency security to maximize the expected profit of operator. To deal with various uncertainties, a risk-constrained two-stage stochastic programming model is proposed where the risk aversion of MG operator is modeled using...

  1. Auditory evoked responses in musicians during passive vowel listening are modulated by functional connectivity between bilateral auditory-related brain regions.

    Science.gov (United States)

    Kühnis, Jürg; Elmer, Stefan; Jäncke, Lutz

    2014-12-01

    Currently, there is striking evidence showing that professional musical training can substantially alter the response properties of auditory-related cortical fields. Such plastic changes have previously been shown not only to abet the processing of musical sounds, but likewise spectral and temporal aspects of speech. Therefore, here we used the EEG technique and measured a sample of musicians and nonmusicians while the participants were passively exposed to artificial vowels in the context of an oddball paradigm. Thereby, we evaluated whether increased intracerebral functional connectivity between bilateral auditory-related brain regions may promote sensory specialization in musicians, as reflected by altered cortical N1 and P2 responses. This assumption builds on the reasoning that sensory specialization is dependent, at least in part, on the amount of synchronization between the two auditory-related cortices. Results clearly revealed that auditory-evoked N1 responses were shaped by musical expertise. In addition, in line with our reasoning musicians showed an overall increased intracerebral functional connectivity (as indexed by lagged phase synchronization) in theta, alpha, and beta bands. Finally, within-group correlative analyses indicated a relationship between intracerebral beta band connectivity and cortical N1 responses, however only within the musicians' group. Taken together, we provide first electrophysiological evidence for a relationship between musical expertise, auditory-evoked brain responses, and intracerebral functional connectivity among auditory-related brain regions.

  2. Emotional facial expressions evoke faster orienting responses, but weaker emotional responses at neural and behavioural levels compared to scenes: A simultaneous EEG and facial EMG study.

    Science.gov (United States)

    Mavratzakis, Aimee; Herbert, Cornelia; Walla, Peter

    2016-01-01

    In the current study, electroencephalography (EEG) was recorded simultaneously with facial electromyography (fEMG) to determine whether emotional faces and emotional scenes are processed differently at the neural level. In addition, it was investigated whether these differences can be observed at the behavioural level via spontaneous facial muscle activity. Emotional content of the stimuli did not affect early P1 activity. Emotional faces elicited enhanced amplitudes of the face-sensitive N170 component, while its counterpart, the scene-related N100, was not sensitive to emotional content of scenes. At 220-280ms, the early posterior negativity (EPN) was enhanced only slightly for fearful as compared to neutral or happy faces. However, its amplitudes were significantly enhanced during processing of scenes with positive content, particularly over the right hemisphere. Scenes of positive content also elicited enhanced spontaneous zygomatic activity from 500-750ms onwards, while happy faces elicited no such changes. Contrastingly, both fearful faces and negative scenes elicited enhanced spontaneous corrugator activity at 500-750ms after stimulus onset. However, relative to baseline EMG changes occurred earlier for faces (250ms) than for scenes (500ms) whereas for scenes activity changes were more pronounced over the whole viewing period. Taking into account all effects, the data suggests that emotional facial expressions evoke faster attentional orienting, but weaker affective neural activity and emotional behavioural responses compared to emotional scenes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Organization of sensory discrimination and response selection in choice and nonchoice conditions: a study using cerebral evoked potentials in normal humans.

    Science.gov (United States)

    Goodin, D S; Aminoff, M J; Shefrin, S L

    1990-10-01

    1. It has been suggested that the long-latency "event-related" cerebral evoked potentials (ERPs) reflect certain aspects of the neural processing underlying sensory discrimination in a two-choice reaction time task. The present paper examines the hypothesis that the coupling of these ERPs to sensory discrimination is variable and that the discrimination process is completed at different points during the course of cerebral processing, depending on the actual requirements of the task. 2. We recorded the cerebral evoked potentials and electromyogram (EMG) of the responding muscle in five different reaction time tasks, each requiring sensory discrimination and response selection of varying complexity. In the Choice condition two stimuli were presented, and two separate responses were required. In the two Go-No Go conditions two stimuli were presented, but a response was required to only one or the other of the stimuli. In the two Simple conditions only one stimulus was presented, and one response was required. 3. Under both Choice and Go-No Go conditions, the frequency histogram of the onset latency of the compound muscle action potential for the response to the frequent tone showed a bimodal distribution without overlap, suggesting that there were two distinct types of responder: fast and slow. The comparable histograms for the onset latency of the response to the rare tone also showed a bimodal distribution, but the mean onset latency was prolonged relative to the response to the frequent tone, and the mean separation was less so that the two distributions overlapped each other. 4. Despite the marked difference in response latencies between the fast and slow responders, there was no appreciable difference in cerebral evoked responses between the two groups. Moreover, in response to the frequent tone, all slow responders and, likewise, all fast responders had similar onset latencies of the averaged EMG activity regardless of condition. Nonetheless, fast or slow

  4. Longitudinal changes in task-evoked brain responses in Parkinson’s disease patients with and without mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Urban eEkman

    2014-07-01

    Full Text Available Cognitive deficits are common in Parkinson’s disease. Previous cross-sectional research has demonstrated a link between cognitive impairments and fronto-striatal dopaminergic dysmodulation. However, longitudinal studies that link disease progression with altered task-evoked brain activity are lacking. Therefore, our objective was to longitudinally evaluate working-memory related brain activity changes in Parkinson’s disease patients with and without mild cognitive impairment.Patients were recruited within a longitudinal cohort study of incident patients with idiopathic parkinsonism. We longitudinally (at baseline examination and at 12-months follow-up compared 28 patients with Parkinson’s disease without mild cognitive impairment with 11 patients with Parkinson’s disease and mild cognitive impairment. Functional MRI blood oxygen level dependent signal was measured during a verbal two-back working-memory task. Patients with mild cognitive impairment under-recruited bilateral medial prefrontal cortex, right putamen, and lateral parietal cortex at both time-points (main effect of group: p<0.001, uncorrected. Critically, a significant group-by-time interaction effect (p<0.001, uncorrected was found in the right fusiform gyrus, indicating that working-memory related activity decreased for patients with Parkinson’s disease and mild cognitive impairment between baseline and follow-up, while patients without mild cognitive impairment were stable across time-points. The functional connectivity between right fusiform gyrus and bilateral caudate nucleus was stronger for patients without MCI relative to patients with MCI.Our findings support the view that deficits in working-memory updating are related to persistent fronto-striatal under-recruitments in patients with early phase Parkinson’s disease and mild cognitive impairment. The longitudinal evolution of mild cognitive impairment in Parkinson’s disease translates into additional task-evoked

  5. 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

    2006-02-01

    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

  6. Improving the detection of evoked responses to periodic stimulation by using bivariate local spectral F-test - Application to EEG during photic stimulation.

    Science.gov (United States)

    Felix, Leonardo Bonato; Rocha, Paulo Fábio; Mendes, Eduardo Mazoni Andrade Marçal; Miranda de Sá, Antonio Mauricio Ferreira Leite

    2017-10-01

    The spectral local F-test has been applied for detecting evoked responses to rhythmic stimulation that are embedded in the ongoing electroencephalogram (EEG). Based on the sampling distribution of a flat spectrum at the neighbourhood of the stimulation frequency, spectral peaks in an EEG signal that are due to the stimulation may be readily assessed. Nevertheless, the performance of the technique is strongly affected by both the signal-to-noise ratio (SNR) of the responses and the number of data segments used in the estimation. The present work aims at both deriving and evaluating a multivariate extension of local F-test by including the EEG collected at a second distinct derivation. The detection rate with this multivariate detector was found to be greater than that using a single channel in case of equal SNR in both signals. Monte Carlo simulation results showed that the probability of detection with this new detector saturates for signal-to-noise ratios above 12 dB and indicated a greater detection rate in practical situations, even when smaller SNR-values are found in the added signal (e.g. 5 dB for 16 neighbouring frequencies used in the estimation). The technique was next applied to the EEG from 12 subjects during intermittent, photic stimulation leading to superior performance in comparison with the univariate local F-test. Since a higher detection rate with the proposed technique is achieved without the need of increasing the number of data segments, it allows evoked responses to be detected faster, once the same detection rate may be accomplished with less segments. This might be useful in clinical practice. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. Evaluation of Reliability in Risk-Constrained Scheduling of Autonomous Microgrids with Demand Response and Renewable Resources

    DEFF Research Database (Denmark)

    Vahedipour-Dahraie, Mostafa; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

    2018-01-01

    Uncertain natures of the renewable energy resources and consumers’ participation in demand response (DR) programs have introduced new challenges to the energy and reserve scheduling of microgrids, particularly in the autonomous mode. In this paper, a risk-constrained stochastic framework...... by using conditional value at risk (CVaR) method. The influence of consumers’ participation in DR programs and their emergency load shedding for different values of lost load (VOLL) are then investigated on the expected profit of operator, CVaR, expected energy not served (EENS) and scheduled reserves...... of microgrid. Moreover, the impacts of different VOLL and risk aversion parameter are illustrated on the system reliability. Extensive simulation results are also presented to illustrate the impact of risk aversion on system security issues with and without DR. Numerical results demonstrate the advantages...

  8. Investigation of human visual cortex responses to flickering light using functional near infrared spectroscopy and constrained ICA

    Directory of Open Access Journals (Sweden)

    Nguyen Duc Thang

    2014-11-01

    Full Text Available The human visual sensitivity to the flickering light has been under investigation for decades. The finding of research in this area can contribute to the understanding of human visual system mechanism and visual disorders, and establishing diagnosis and treatment of diseases. The aim of this study is to investigate the effects of the flickering light to the visual cortex by monitoring the hemodynamic responses of the brain with the functional near infrared spectroscopy (fNIRS method. Since the acquired fNIRS signals are affected by physiological factors and measurement artifacts, constrained independent component analysis (cICA was applied to extract the actual fNIRS responses from the obtained data. The experimental results revealed significant changes (p < 0.0001 of the hemodynamic responses of the visual cortex from the baseline when the flickering stimulation was activated. With the uses of cICA, the contrast to noise ratio (CNR, reflecting the contrast of hemodynamic concentration between rest and task, became larger. This indicated the improvement of the fNIRS signals when the noise was eliminated. In subsequent studies, statistical analysis was used to infer the correlation between the fNIRS signals and the visual stimulus. We found that there was a slight decrease of the oxygenated hemoglobin concentration (about 5.69% over four frequencies when the modulation increased. However, the variations of oxy and deoxy-hemoglobin were not statistically significant.

  9. Age-Related Differences in Response to Music-Evoked Emotion among Children and Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

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

    2016-01-01

    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…

  10. Phytoplankton responses to temperature increases are constrained by abiotic conditions and community composition.

    Science.gov (United States)

    Striebel, Maren; Schabhüttl, Stefanie; Hodapp, Dorothee; Hingsamer, Peter; Hillebrand, Helmut

    2016-11-01

    Effects of temperature changes on phytoplankton communities seem to be highly context-specific, but few studies have analyzed whether this context specificity depends on differences in the abiotic conditions or in species composition between studies. We present an experiment that allows disentangling the contribution of abiotic and biotic differences in shaping the response to two aspects of temperature change: permanent increase of mean temperature versus pulse disturbance in form of a heat wave. We used natural communities from six different sites of a floodplain system as well as artificially mixed communities from laboratory cultures and grew both, artificial and natural communities, in water from the six different floodplain lakes (sites). All 12 contexts (2 communities × 6 sites) were first exposed to three different temperature levels (12, 18, 24 °C, respectively) and afterward to temperature pulses (4 °C increase for 7 h day(-1)). Temperature-dependent changes in biomass and community composition depended on the initial composition of phytoplankton communities. Abiotic conditions had a major effect on biomass of phytoplankton communities exposed to different temperature conditions, however, the effect of biotic and abiotic conditions together was even more pronounced. Additionally, phytoplankton community responses to pulse temperature effects depended on the warming history. By disentangling abiotic and biotic effects, our study shows that temperature-dependent effects on phytoplankton communities depend on both, biotic and abiotic constraints.

  11. Visual cortex modulates the magnitude but not the selectivity of looming-evoked responses in the superior colliculus of awake mice.

    Science.gov (United States)

    Zhao, Xinyu; Liu, Mingna; Cang, Jianhua

    2014-10-01

    Neural circuits in the brain often receive inputs from multiple sources, such as the bottom-up input from early processing stages and the top-down input from higher-order areas. Here we study the function of top-down input in the mouse superior colliculus (SC), which receives convergent inputs from the retina and visual cortex. Neurons in the superficial SC display robust responses and speed tuning to looming stimuli that mimic approaching objects. The looming-evoked responses are reduced by almost half when the visual cortex is optogenetically silenced in awake, but not in anesthetized, mice. Silencing the cortex does not change the looming speed tuning of SC neurons, or the response time course, except at the lowest tested speed. Furthermore, the regulation of SC responses by the corticotectal input is organized retinotopically. This effect we revealed may thus provide a potential substrate for the cortex, an evolutionarily new structure, to modulate SC-mediated visual behaviors. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Sensitivity of primary phasic heart rate deceleration to stimulus repetition in an habituation procedure: influence of a subjective measure of activation/arousal on the evoked cardiac response.

    Science.gov (United States)

    Binder, Marek; Barry, Robert J; Kaiser, Jan

    2005-01-01

    The post-stimulus primary bradycardia--sometimes labelled as the first evoked cardiac response, ECR1--is regarded as a response which is independent of the stimulus novelty factor. Despite this however, in our previous research we have observed a noticeable variation of this response, which made us suspect that there could be some additional factor influencing it. To test this, we designed a habituation procedure to measure susceptibility of the ECR1 to stimulus repetition. In our experimental design, we also included a measure of the level of activation (arousal) as a possible additional factor influencing the time-course of the cardiac response. The level of arousal over the study was measured by the Activation-Deactivation Adjective Check List (AD ACL). Our results show that mere stimulus repetition does not influence the time-course of ECR1. However, another pattern of results appeared when one of the dimensions of AD ACL, namely Tense Arousal, was taken into account. We observed different ECR time-courses during the initial stimulus presentations for subjects with high and low levels of Tense Arousal. These results are interpreted within the framework of Preliminary Process Theory in terms of the different attentional patterns in subjects with high and low levels of Tense Arousal.

  13. Ultra-low-noise EEG/MEG systems enable bimodal non-invasive detection of spike-like human somatosensory evoked responses at 1 kHz.

    Science.gov (United States)

    Fedele, T; Scheer, H J; Burghoff, M; Curio, G; Körber, R

    2015-02-01

    Non-invasive EEG detection of very high frequency somatosensory evoked potentials featuring frequencies up to and above 1 kHz has been recently reported. Here, we establish the detectability of such components by combined low-noise EEG/MEG. We recorded SEP/SEF simultaneously using median nerve stimulation in five healthy human subjects inside an electromagnetically shielded room, combining a low-noise EEG custom-made amplifier (4.7 nV/√Hz) and a custom-made single-channel low-noise MEG (0.5 fT/√Hz @ 1 kHz). Both, low-noise EEG and MEG revealed three spectrally distinct and temporally overlapping evoked components: N20 (EEG [10 nV] ≅ MEG [1 fT]). Pronounced waveform (peak-by-peak) overlap of EEG and MEG signals is observed in the sigma band, whereas in the kappa band overlap was only partial. A decreasing signal-to-noise ratio (SNR; calculated for n = 12.000 averages) from sigma to kappa components characterizes both, electric and magnetic field recordings: Sigma-band SNR was 12.9  ±  5.5/19.8  ±  12.6 for EEG/MEG, and kappa-band SNR at 3.77  ±  0.8/4.5  ±  2.9. High-frequency performance of a tailor-made MEG matches closely with simultaneously recorded low-noise EEG for the non-invasive detection of somatosensory evoked activity at and above 1 kHz. Thus, future multi-channel dual-mode low-noise technology could offer complementary views for source reconstruction of the neural generators underlying such high-frequency responses, and render neural high-frequency processes related to multi-unit spike discharges accessible in non-invasive recordings.

  14. Wiener kernel analysis of a noise-evoked otoacoustic emission

    NARCIS (Netherlands)

    van Dijk, P; Maat, A; Wit, H P

    1997-01-01

    In one specimen of the frog species, Rana esculenta, the following were measured: (1) a spontaneous otoacoustic emission; (2) a click-evoked otoacoustic emissions; and (3) a noise evoked otoacoustic emission. From the noise evoked emission response, a first-and a second-order Wiener kernel and the

  15. The spectral features of EEG responses to transcranial magnetic stimulation of the primary motor cortex depend on the amplitude of the motor evoked potentials.

    Science.gov (United States)

    Fecchio, Matteo; Pigorini, Andrea; Comanducci, Angela; Sarasso, Simone; Casarotto, Silvia; Premoli, Isabella; Derchi, Chiara-Camilla; Mazza, Alice; Russo, Simone; Resta, Federico; Ferrarelli, Fabio; Mariotti, Maurizio; Ziemann, Ulf; Massimini, Marcello; Rosanova, Mario

    2017-01-01

    Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) can excite both cortico-cortical and cortico-spinal axons resulting in TMS-evoked potentials (TEPs) and motor-evoked potentials (MEPs), respectively. Despite this remarkable difference with other cortical areas, the influence of motor output and its amplitude on TEPs is largely unknown. Here we studied TEPs resulting from M1 stimulation and assessed whether their waveform and spectral features depend on the MEP amplitude. To this aim, we performed two separate experiments. In experiment 1, single-pulse TMS was applied at the same supra-threshold intensity on primary motor, prefrontal, premotor and parietal cortices and the corresponding TEPs were compared by means of local mean field power and time-frequency spectral analysis. In experiment 2 we stimulated M1 at resting motor threshold in order to elicit MEPs characterized by a wide range of amplitudes. TEPs computed from high-MEP and low-MEP trials were then compared using the same methods applied in experiment 1. In line with previous studies, TMS of M1 produced larger TEPs compared to other cortical stimulations. Notably, we found that only TEPs produced by M1 stimulation were accompanied by a late event-related desynchronization (ERD-peaking at ~300 ms after TMS), whose magnitude was strongly dependent on the amplitude of MEPs. Overall, these results suggest that M1 produces peculiar responses to TMS possibly reflecting specific anatomo-functional properties, such as the re-entry of proprioceptive feedback associated with target muscle activation.

  16. Sound-Making Actions Lead to Immediate Plastic Changes of Neuromagnetic Evoked Responses and Induced β-Band Oscillations during Perception.

    Science.gov (United States)

    Ross, Bernhard; Barat, Masihullah; Fujioka, Takako

    2017-06-14

    Auditory and sensorimotor brain areas interact during the action-perception cycle of sound making. Neurophysiological evidence of a feedforward model of the action and its outcome has been associated with attenuation of the N1 wave of auditory evoked responses elicited by self-generated sounds, such as talking and singing or playing a musical instrument. Moreover, neural oscillations at β-band frequencies have been related to predicting the sound outcome after action initiation. We hypothesized that a newly learned action-perception association would immediately modify interpretation of the sound during subsequent listening. Nineteen healthy young adults (7 female, 12 male) participated in three magnetoencephalographic recordings while first passively listening to recorded sounds of a bell ringing, then actively striking the bell with a mallet, and then again listening to recorded sounds. Auditory cortex activity showed characteristic P1-N1-P2 waves. The N1 was attenuated during sound making, while P2 responses were unchanged. In contrast, P2 became larger when listening after sound making compared with the initial naive listening. The P2 increase occurred immediately, while in previous learning-by-listening studies P2 increases occurred on a later day. Also, reactivity of β-band oscillations, as well as θ coherence between auditory and sensorimotor cortices, was stronger in the second listening block. These changes were significantly larger than those observed in control participants (eight female, five male), who triggered recorded sounds by a key press. We propose that P2 characterizes familiarity with sound objects, whereas β-band oscillation signifies involvement of the action-perception cycle, and both measures objectively indicate functional neuroplasticity in auditory perceptual learning. SIGNIFICANCE STATEMENT While suppression of auditory responses to self-generated sounds is well known, it is not clear whether the learned action-sound association

  17. 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

    2013-01-01

    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.

  18. 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

    2001-01-01

    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...

  19. Constraining the near-surface response to lithospheric reorientation: Structural thermochronology along the TRANSALP geophysical transect

    Science.gov (United States)

    Glotzbach, Christoph; Büttner, Lukas; Ehlers, Todd

    2017-04-01

    Tomographic analyses of the lithosphere structure underneath the Alps suggest a complex geodynamic history (e.g. Lippitsch et al. 2003), indicating, among other things, switches in the direction of subduction. A subduction polarity switch is proposed to have occurred in Miocene times between the Central and Eastern Alps (e.g. Lippitsch et al. 2003; Handy et al. 2015). In the Western and Central Alps SE-directed subduction of European continental lithosphere occurs, whereas NW-directed subduction of Adriatic lithosphere occurs further east (e.g. Kissling et al. 2006). The subducted slab steepens at the transition to the Eastern Alps, roughly at the position of the TRANSALP geophysical profile (S. Germany to N. Italy). This lithospheric reorientation was pre-dated by slab breakoff and also involves the delamination of the lower lithosphere, both processes producing distinct long-wavelength deformation (e.g. Gerya et al. 2004). Thermochronological data can be used to study the surface response to such a long-wavelength deformation. We present new apatite and zircon (U-Th)/He ages of 23 samples collected along 210 km of the TRANSALP profile. The samples were collected along a balanced cross section the TRANSALP profile (e.g. Lüschen et al. 2004) across individual structures that can be tied to deeper, seismically imaged, structures. The thermochronometer ages provide a record of exhumation related to both crustal shortening and post deformation erosional exhumation. Interpretation of the data is in progress and being used to discriminate between competing kinematic/geometric models, and the timing of major fault activity. Variations in exhumation along the section will also unravel the timing and shape of possible long-wavelength rock uplift event(s). References Gerya, T.V., Yuen, D.A., Maresch, W.V. 2004. Thermomechanical modelling of slab detachment. Earth Planet. Sci. Lett. 226, 101-116. Handy, M.R., Ustaszewski, K., Kissling, E. 2015. Reconstructing the Alps

  20. Reliability of the Achilles tendon tap reflex evoked during stance using a pendulum hammer.

    Science.gov (United States)

    Mildren, Robyn L; Zaback, Martin; Adkin, Allan L; Frank, James S; Bent, Leah R

    2016-01-01

    The tendon tap reflex (T-reflex) is often evoked in relaxed muscles to assess spinal reflex circuitry. Factors contributing to reflex excitability are modulated to accommodate specific postural demands. Thus, there is a need to be able to assess this reflex in a state where spinal reflex circuitry is engaged in maintaining posture. The aim of this study was to determine whether a pendulum hammer could provide controlled stimuli to the Achilles tendon and evoke reliable muscle responses during normal stance. A second aim was to establish appropriate stimulus parameters for experimental use. Fifteen healthy young adults stood on a forceplate while taps were applied to the Achilles tendon under conditions in which postural sway was constrained (by providing centre of pressure feedback) or unconstrained (no feedback) from an invariant release angle (50°). Twelve participants repeated this testing approximately six months later. Within one experimental session, tap force and T-reflex amplitude were found to be reliable regardless of whether postural sway was constrained (tap force ICC=0.982; T-reflex ICC=0.979) or unconstrained (tap force ICC=0.968; T-reflex ICC=0.964). T-reflex amplitude was also reliable between experimental sessions (constrained ICC=0.894; unconstrained ICC=0.890). When a T-reflex recruitment curve was constructed, optimal mid-range responses were observed using a 50° release angle. These results demonstrate that reliable Achilles T-reflexes can be evoked in standing participants without the need to constrain posture. The pendulum hammer provides a simple method to allow researchers and clinicians to gather information about reflex circuitry in a state where it is involved in postural control. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Functional selectivity of central Gα-subunit proteins in mediating the cardiovascular and renal excretory responses evoked by central α(2) -adrenoceptor activation in vivo.

    Science.gov (United States)

    Wainford, R D; Kapusta, D R

    2012-05-01

    Activation of brain α(2) -adrenoceptors in conscious rodents decreases heart rate (HR) and mean arterial blood pressure (MAP) and increases urine output and urinary sodium excretion. In vitro, α(2) -adrenoceptor stimulation activates Gα(i(1-3)) , Gα(o) and Gα(s) -subunit protein-gated signal transduction pathways. Here we have investigated whether these same Gα-subunit protein-gated pathways mediate the cardiovascular and renal excretory responses to central α(2) -adrenoceptor activation in conscious Sprague-Dawley rats. Rats were pre-treated by intracerebroventricular injection (i.c.v.) with an oligodeoxynucleotide (ODN) targeted to a Gα(i1) , Gα(i2) , Gα(i3) , Gα(o) , Gα(s) or a scrambled (SCR) ODN sequence (25 µg, 24 h). On the day of study, the α(2) -adrenoceptor agonist guanabenz (50 µg) or saline vehicle, was injected i.c.v. into ODN-pre-treated conscious rats. MAP and HR were recorded, and urine was collected for 150 min. In vehicle- and SCR ODN-pre-treated rats, i.c.v. guanabenz decreased MAP and HR, and produced marked diuretic and natriuretic responses. Selective ODN-mediated down-regulation of brain Gα(i2) -subunit proteins abolished the central guanabenz-induced hypotension and natriuresis. In contrast, following selective Gα(s) down-regulation, the characteristic hypotensive response to i.c.v. guanabenz was converted to an immediate increase in MAP. The bradycardic and diuretic responses to i.c.v. guanabenz were not blocked by pre-treatment with any ODN. There was functional selectivity of Gα(i2) and Gα(s) subunit protein-gated signal transduction pathways in mediating the hypotensive and natriuretic, but not bradycardic or diuretic, responses evoked by central α(2) -adrenoceptor activation in vivo. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  2. Training signaling pathway maps to biochemical data with constrained fuzzy logic: quantitative analysis of liver cell responses to inflammatory stimuli.

    Directory of Open Access Journals (Sweden)

    Melody K Morris

    2011-03-01

    Full Text Available Predictive understanding of cell signaling network operation based on general prior knowledge but consistent with empirical data in a specific environmental context is a current challenge in computational biology. Recent work has demonstrated that Boolean logic can be used to create context-specific network models by training proteomic pathway maps to dedicated biochemical data; however, the Boolean formalism is restricted to characterizing protein species as either fully active or inactive. To advance beyond this limitation, we propose a novel form of fuzzy logic sufficiently flexible to model quantitative data but also sufficiently simple to efficiently construct models by training pathway maps on dedicated experimental measurements. Our new approach, termed constrained fuzzy logic (cFL, converts a prior knowledge network (obtained from literature or interactome databases into a computable model that describes graded values of protein activation across multiple pathways. We train a cFL-converted network to experimental data describing hepatocytic protein activation by inflammatory cytokines and demonstrate the application of the resultant trained models for three important purposes: (a generating experimentally testable biological hypotheses concerning pathway crosstalk, (b establishing capability for quantitative prediction of protein activity, and (c prediction and understanding of the cytokine release phenotypic response. Our methodology systematically and quantitatively trains a protein pathway map summarizing curated literature to context-specific biochemical data. This process generates a computable model yielding successful prediction of new test data and offering biological insight into complex datasets that are difficult to fully analyze by intuition alone.

  3. Training signaling pathway maps to biochemical data with constrained fuzzy logic: quantitative analysis of liver cell responses to inflammatory stimuli.

    Science.gov (United States)

    Morris, Melody K; Saez-Rodriguez, Julio; Clarke, David C; Sorger, Peter K; Lauffenburger, Douglas A

    2011-03-01

    Predictive understanding of cell signaling network operation based on general prior knowledge but consistent with empirical data in a specific environmental context is a current challenge in computational biology. Recent work has demonstrated that Boolean logic can be used to create context-specific network models by training proteomic pathway maps to dedicated biochemical data; however, the Boolean formalism is restricted to characterizing protein species as either fully active or inactive. To advance beyond this limitation, we propose a novel form of fuzzy logic sufficiently flexible to model quantitative data but also sufficiently simple to efficiently construct models by training pathway maps on dedicated experimental measurements. Our new approach, termed constrained fuzzy logic (cFL), converts a prior knowledge network (obtained from literature or interactome databases) into a computable model that describes graded values of protein activation across multiple pathways. We train a cFL-converted network to experimental data describing hepatocytic protein activation by inflammatory cytokines and demonstrate the application of the resultant trained models for three important purposes: (a) generating experimentally testable biological hypotheses concerning pathway crosstalk, (b) establishing capability for quantitative prediction of protein activity, and (c) prediction and understanding of the cytokine release phenotypic response. Our methodology systematically and quantitatively trains a protein pathway map summarizing curated literature to context-specific biochemical data. This process generates a computable model yielding successful prediction of new test data and offering biological insight into complex datasets that are difficult to fully analyze by intuition alone.

  4. Evaluation of the occurrence of canine congenital sensorineural deafness in puppies of predisposed dog breeds using the brainstem auditory evoked response.

    Science.gov (United States)

    Płonek, Marta; Giza, Elżbieta; Niedźwiedź, Artur; Kubiak, Krzysztof; Nicpoń, Józef; Wrzosek, Marcin

    2016-12-01

    Canine congenital sensorineural deafness (CCSD) affects predisposed breeds of dogs and is primarily caused by an atrophy of the stria vascularis of the organ of Corti. The analysis of the brainstem auditory evoked response (BAER) is a reliable method for the evaluation of hearing in animals as it allows an accurate detection of unilateral or bilateral deafness. The occurrence of unilateral and bilateral deafness using the BAER was determined in a representative group of dogs in Poland, including Bull Terriers (n = 117), Australian Cattle Dogs (n = 62), English Setters (n = 32) and the Dogo Argentino (n = 32). Overall deafness, deafness in each dog breed and an association between deafness and phenotype were studied. Among the 243 dogs tested, 156 (81%) had a normal BAER, 27 (11%) were unilaterally deaf, and 12 (5%) were bilaterally deaf. The amplitudes and latencies of waves I, II, III, V, the V/I wave amplitude ratio, and wave I-V, I-III and III-V inter-peak intervals were recorded for each dog. Unilaterally and bilaterally deaf dogs were present in all the dog breeds studied. There were 17 (14.5%) deaf Bull Terriers, three (4.8%) deaf Australian Cattle Dogs, seven (21.9%) deaf English Setters, and 12 (37.5%) deaf Dogos Argentinos. Preventive BAER screening should be routinely performed in these four breeds to prevent the spread of genes responsible for deafness.

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

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    Yumi Maeda

    2013-01-01

    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.

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

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    Masato Nakai

    2015-10-01

    Full Text Available 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 (dsRNA. 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.

  7. Choosing to Stop: Responses Evoked by Externally Triggered and Internally Generated Inhibition Identify a Neural Mechanism of Will.

    Science.gov (United States)

    Parkinson, Jim; Haggard, Patrick

    2015-10-01

    Inhibiting inappropriate action is key to human behavioral control. Studies of action inhibition largely investigated external stop signals, yet these are rare in everyday life. Instead healthy adults exert "self-control," implying an ability to decide internally to stop actions. We added "choose for yourself" stimuli to a conventional go/no-go task to compare reactive versus intentional action and inhibition. No-go reactions showed the N2 EEG potential characteristic of inhibiting prepotent motor responses, whereas go reactions did not. Interestingly, the N2 component was present for intentional choices both to act and also to inhibit. Thus, free choices involved a first step of intentionally inhibiting prepotent responses before generating or withholding an action. Intentional inhibition has a crucial role breaking the flow of stimulus-driven responding, allowing expression of volitional decisions. Even decisions to initiate self-generated actions require this prior negative form of volition, ensuring the "freedom from immediacy" characteristic of human behavior.

  8. The indolic compound hypaphorine produced by ectomycorrhizal fungus interferes with auxin action and evokes early responses in nonhost Arabidopsis thaliana.

    Science.gov (United States)

    Reboutier, David; Bianchi, Michele; Brault, Mathias; Roux, Camille; Dauphin, Aurélien; Rona, Jean-Pierre; Legué, Valérie; Lapeyrie, Frédéric; Bouteau, François

    2002-09-01

    Signals leading to mycorrhizal differentiation are largely unknown. We have studied the sensitivity of the root system from plant model Arabidopsis thaliana to hypaphorine, the major indolic compound isolated from the basidiomycetous fungus Pisolithus tinctorius. This fungi establishes ectomycorrhizas with Eucalyptus globulus. Hypaphorine controls root hair elongation and counteracts the activity of indole-3-acetic acid on root elongation on A. thaliana, as previously reported for the host plant. In addition, we show that hypaphorine counteracts the rapid upregulation by indole-3-acetic acid and 1-naphthalenic-acetic acid of the primary auxin-responsive gene IAA1 and induces a rapid, transient membrane depolarization in root hairs and suspension cells, due to the modulation of anion and K+ currents. These early responses indicate that components necessary for symbiosis-related differentiation events are present in the nonhost plant A. thaliana and provide tools for the dissection of the hypaphorine-auxin interaction.

  9. Asymmetric Correlation between Experienced Parental Attachment and Event-Related Potentials Evoked in Response to Parental Faces

    Science.gov (United States)

    Dai, Junqiang; Zhai, Hongchang; Zhou, Anbang; Gong, Yongyuan; Luo, Lin

    2013-01-01

    This study aims to explore the modulation effects of attachment relationships with parents on the neural correlates that are associated with parental faces. The event-related potentials elicited in 31 college students while viewing facial stimuli of their parents in two single oddball paradigms (father vs. unfamiliar male and mother vs. unfamiliar female) were measured. We found that enhanced P3a and P3b and attenuated N2b were elicited by parental faces; however, the N170 component failed to discriminate parental faces from unfamiliar faces. An experienced attachment relationship with the father was positively correlated to the P3a response associated with the father’s face, whereas no correlation was found in the case of mothers. Further exploration in dipole source localization showed that, within the time window of the P300, distinctive brain regions were involved in the processing of parental faces; the father’s face was located in the medial frontal gyrus, which might be involved in self effect, and the anterior cingulate gyrus was activated in response to the mother’s face. This research is the first to demonstrate that neural mechanisms involved with parents can be modulated differentially by the qualities of the attachments to the parents. In addition, parental faces share a highly similar temporal pattern, but the origins of these neural responses are distinct, which could merit further investigation. PMID:23844240

  10. Asymmetric correlation between experienced parental attachment and event-related potentials evoked in response to parental faces.

    Directory of Open Access Journals (Sweden)

    Junqiang Dai

    Full Text Available This study aims to explore the modulation effects of attachment relationships with parents on the neural correlates that are associated with parental faces. The event-related potentials elicited in 31 college students while viewing facial stimuli of their parents in two single oddball paradigms (father vs. unfamiliar male and mother vs. unfamiliar female were measured. We found that enhanced P3a and P3b and attenuated N2b were elicited by parental faces; however, the N170 component failed to discriminate parental faces from unfamiliar faces. An experienced attachment relationship with the father was positively correlated to the P3a response associated with the father's face, whereas no correlation was found in the case of mothers. Further exploration in dipole source localization showed that, within the time window of the P300, distinctive brain regions were involved in the processing of parental faces; the father's face was located in the medial frontal gyrus, which might be involved in self effect, and the anterior cingulate gyrus was activated in response to the mother's face. This research is the first to demonstrate that neural mechanisms involved with parents can be modulated differentially by the qualities of the attachments to the parents. In addition, parental faces share a highly similar temporal pattern, but the origins of these neural responses are distinct, which could merit further investigation.

  11. Injection of a recombinant AAV serotype 2 into canine skeletal muscles evokes strong immune responses against transgene products.

    Science.gov (United States)

    Yuasa, K; Yoshimura, M; Urasawa, N; Ohshima, S; Howell, J M; Nakamura, A; Hijikata, T; Miyagoe-Suzuki, Y; Takeda, S

    2007-09-01

    Using murine models, we have previously demonstrated that recombinant adeno-associated virus (rAAV)-mediated microdystrophin gene transfer is a promising approach to treatment of Duchenne muscular dystrophy (DMD). To examine further therapeutic effects and the safety issue of rAAV-mediated microdystrophin gene transfer using larger animal models, such as dystrophic dog models, we first investigated transduction efficiency of rAAV in wild-type canine muscle cells, and found that rAAV2 encoding beta-galactosidase effectively transduces canine primary myotubes in vitro. Subsequent rAAV2 transfer into skeletal muscles of normal dogs, however, resulted in low and transient expression of beta-galactosidase together with intense cellular infiltrations in vivo, where cellular and humoral immune responses were remarkably activated. In contrast, rAAV2 expressing no transgene elicited no cellular infiltrations. Co-administration of immunosuppressants, cyclosporine and mycophenolate mofetil could partially improve rAAV2 transduction. Collectively, these results suggest that immune responses against the transgene product caused cellular infiltration and eliminated transduced myofibers in dogs. Furthermore, in vitro interferon-gamma release assay showed that canine splenocytes respond to immunogens or mitogens more susceptibly than murine ones. Our results emphasize the importance to scrutinize the immune responses to AAV vectors in larger animal models before applying rAAV-mediated gene therapy to DMD patients.

  12. Plasticity of the mate choice mind: courtship evokes choice-like brain responses in females from a coercive mating system.

    Science.gov (United States)

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

    2014-04-01

    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. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  13. Intracisternal injection of palmitoylethanolamide inhibits the peripheral nociceptive evoked responses of dorsal horn wide dynamic range neurons.

    Science.gov (United States)

    González-Hernández, Abimael; Martínez-Lorenzana, Guadalupe; Rodríguez-Jiménez, Javier; Rojas-Piloni, Gerardo; Condés-Lara, Miguel

    2015-03-01

    Endogenous palmitoylethanolamide (PEA) has a key role in pain modulation. Central or peripheral PEA can reduce nociceptive behavior, but no study has yet reported a descending inhibitory effect on the neuronal nociceptive activity of Aδ- and C-fibers. This study shows that intracisternal PEA inhibits the peripheral nociceptive responses of dorsal horn wide dynamic range cells (i.e., inhibition of Aδ- and C-fibers), an effect blocked by spinal methiothepin. These results suggest that a descending analgesic mechanism mediated by the serotonergic system could be activated by central PEA.

  14. Single-subject analyses of magnetoencephalographic evoked responses to the acoustic properties of affective non-verbal vocalizations.

    Science.gov (United States)

    Salvia, Emilie; Bestelmeyer, Patricia E G; Kotz, Sonja A; Rousselet, Guillaume A; Pernet, Cyril R; Gross, Joachim; Belin, Pascal

    2014-01-01

    Magneto-encephalography (MEG) was used to examine the cerebral response to affective non-verbal vocalizations (ANVs) at the single-subject level. Stimuli consisted of non-verbal affect bursts from the Montreal Affective Voices morphed to parametrically vary acoustical structure and perceived emotional properties. Scalp magnetic fields were recorded in three participants while they performed a 3-alternative forced choice emotion categorization task (Anger, Fear, Pleasure). Each participant performed more than 6000 trials to allow single-subject level statistical analyses using a new toolbox which implements the general linear model (GLM) on stimulus-specific responses (LIMO-EEG). For each participant we estimated "simple" models [including just one affective regressor (Arousal or Valence)] as well as "combined" models (including acoustical regressors). Results from the "simple" models revealed in every participant the significant early effects (as early as ~100 ms after onset) of Valence and Arousal already reported at the group-level in previous work. However, the "combined" models showed that few effects of Arousal remained after removing the acoustically-explained variance, whereas significant effects of Valence remained especially at late stages. This study demonstrates (i) that single-subject analyses replicate the results observed at early stages by group-level studies and (ii) the feasibility of GLM-based analysis of MEG data. It also suggests that early modulation of MEG amplitude by affective stimuli partly reflects their acoustical properties.

  15. Single-subject analyses of magnetoencephalographic evoked responses to the acoustic properties of affective non-verbal vocalizations

    Directory of Open Access Journals (Sweden)

    Emilie eSalvia

    2014-12-01

    Full Text Available Magneto-encephalography (MEG was used to examine the cerebral response to affective non-verbal vocalizations (ANVs at the single-subject level. Stimuli consisted of nonverbal affect bursts from the Montreal Affective Voices morphed to parametrically vary acoustical structure and perceived emotional properties. Scalp magnetic fields were recorded in three participants while they performed a 3-alternative forced choice emotion categorization task (Anger, Fear, Pleasure. Each participant performed more than 6000 trials to allow single-subject level statistical analyses using a new toolbox which implements the general linear model (GLM on stimulus-specific responses (LIMO-EEG. For each participant we estimated ‘simple’ models (including just one affective regressor (Arousal or Valence as well as ‘combined’ models (including acoustical regressors. Results from the ‘simple’ models revealed in every participant the significant early effects (as early as ~100 ms after onset of Valence and Arousal already reported at the group-level in previous work. However, the ‘combined’ models showed that few effects of Arousal remained after removing the acoustically-explained variance, whereas significant effects of Valence remained especially at late stages. This study demonstrates (i that single-subject analyses replicate the results observed at early stages by group-level studies and (ii the feasibility of GLM-based analysis of MEG data. It also suggests that early modulation of MEG amplitude by affective stimuli partly reflects their acoustical properties.

  16. Auditory evoked arousal responses of 3-month-old infants exposed to methamphetamine in utero: a nap study.

    Science.gov (United States)

    Galland, Barbara C; Mitchell, Ed A; Thompson, John M D; Wouldes, Trecia

    2013-04-01

    To investigate whether or not infants exposed to methamphetamine prenatally have impaired arousal responses from sleep. The polygraphic nap studies involved 42 infants aged 3 months exposed to methamphetamine in utero and a comparison group of 57 infants. A proportion of mothers in both groups smoked cigarettes and/or marijuana and drank alcohol during pregnancy. White noise from 50 to 100 decibels (dB) was administered at 10 dB intervals twice within non-rapid eye movement (NREM) and rapid eye movement (REM) sleep states and arousal thresholds measured. Combining groups, 306 tests were completed (128 and 178 within REM and NREM sleep, respectively) and infants were more likely to wake at lower thresholds in REM than NREM sleep (hazard ratio 5.58; 95% CI, 3.78-8.23 p sleep; 0.98, 95% CI, 0.60-1.59 and REM sleep; 1.03, 95% CI, 0.56-1.89). These findings suggest that arousal responses of methamphetamine-exposed infants remain intact, providing no support for the hypothesis that prenatal exposure could increase their vulnerability to sudden infant death syndrome (SIDS) through arousal deficits. ©2012 The Author(s)/Acta Paediatrica ©2012 Foundation Acta Paediatrica.

  17. Homophobia Is Related to a Low Interest in Sexuality in General: An Analysis of Pupillometric Evoked Responses.

    Science.gov (United States)

    Cheval, Boris; Grob, Emmanuelle; Chanal, Julien; Ghisletta, Paolo; Bianchi-Demicheli, Francesco; Radel, Remi

    2016-10-01

    A recent study by Cheval et al (J Sex Med 2016;13:825-834) found that individuals high in homophobia look significantly less long at sex-related photographs, regardless of their nature (ie, homosexual or heterosexual). Because viewing time is under some conscious control, this result could indicate that individuals high in homophobia have a low sexual interest in any sexual stimuli or are consciously motivated to avoid sexual material in line with their conscious values. To determine the mechanism underlying shorter viewing time of sex-related photographs in individuals high in homophobia using pupil dilatation, which is considered a spontaneous, unconscious, and uncontrollable index of sexual interest. Heterosexual men (N = 36) completed a questionnaire assessing their level of homo-negativity and then performed a picture-viewing task with simultaneous eye-tracking recording to assess their pupillary responses to the presentation of sexually related or neutral photographs. Non-linear mixed models were carried out to fit the individual non-linear trajectories of pupillary reaction. Different parameters were obtained including the final asymptote of the pupillary response. Results showed that the final pupil size of men high in homophobia increased significantly less to the presentation of sex-related images (ie, heterosexual and homosexual) than the pupil size of men low in homophobia. In contrast, no significant difference in the final pupil size reaction toward homosexual images (vs heterosexual images) emerged between men high and men low in homophobia. Theoretically, these findings reinforce the necessity to consider that homophobia might reflect concerns about sexuality in general and not homosexuality in particular. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  18. Central and peripheral chemoreceptors evoke distinct responses in simultaneously recorded neurons of the raphé-pontomedullary respiratory network.

    Science.gov (United States)

    Nuding, Sarah C; Segers, Lauren S; Shannon, Roger; O'Connor, Russell; Morris, Kendall F; Lindsey, Bruce G

    2009-09-12

    The brainstem network for generating and modulating the respiratory motor pattern includes neurons of the medullary ventrolateral respiratory column (VRC), dorsolateral pons (PRG) and raphé nuclei. Midline raphé neurons are proposed to be elements of a distributed brainstem system of central chemoreceptors, as well as modulators of central chemoreceptors at other sites, including the retrotrapezoid nucleus. Stimulation of the raphé system or peripheral chemoreceptors can induce a long-term facilitation of phrenic nerve activity; central chemoreceptor stimulation does not. The network mechanisms through which each class of chemoreceptor differentially influences breathing are poorly understood. Microelectrode arrays were used to monitor sets of spike trains from 114 PRG, 198 VRC and 166 midline neurons in six decerebrate vagotomized cats; 356 were recorded during sequential stimulation of both receptor classes via brief CO(2)-saturated saline injections in vertebral (central) and carotid arteries (peripheral). Seventy neurons responded to both stimuli. More neurons were responsive only to peripheral challenges than those responsive only to central chemoreceptor stimulation (PRG, 20 : 4; VRC, 41 : 10; midline, 25 : 13). Of 16 474 pairs of neurons evaluated for short-time scale correlations, similar percentages of reference neurons in each brain region had correlation features indicative of a specific interaction with at least one target neuron: PRG (59.6%), VRC (51.0%) and raphé nuclei (45.8%). The results suggest a brainstem network architecture with connectivity that shapes the respiratory motor pattern via overlapping circuits that modulate central and peripheral chemoreceptor-mediated influences on breathing.

  19. Hearing impairment in children with congenital cytomegalovirus (CMV) infection based on distortion product otoacoustic emissions (DPOAE) and brain evoked response audiometry stimulus click (BERA Click) examinations

    Science.gov (United States)

    Airlangga, T. J.; Mangunatmadja, I.; Prihartono, J.; Zizlavsky, S.

    2017-08-01

    Congenital cytomegalovirus (congenital CMV) infection is a leading factor of nongenetic sensorineural hearing loss in children. Hearing loss caused by CMV infection does not have a pathognomonic configuration hence further research is needed. The development of knowledge on hearing loss caused by congenital CMV infection is progressing in many countries. Due to a lack of research in the context of Indonesia, this study assesses hearing impairment in children with congenital CMV infection in Indonesia, more specifically in the Cipto Mangunkusumo Hospital. Our objective was to profile hearing impairment in children 0-5 years of age with congenital CMV infection using Distortion Product Otoacoustic Emissions (DPOAE) and Brain Evoked Response Audiometry Stimulus Click (BERA Click) examinations. This cross-sectional study was conducted in the Cipto Mangunkusum Hospital from November, 2015 to May 2016 with 27 children 0-5 years of age with congenital CMV infection. Of individual ears studied, 58.0% exhibited sensorineural hearing loss. There was a significant relationship between developmental delay and incidence of sensorineural hearing loss. Subjects with a developmental delay were 6.57 times more likely (CI 95%; 1.88-22.87) to experience sensorineural hearing loss. Congenital CMV infection has an important role in causing sensorineural hearing loss in children.

  20. Innate IFNs and plasmacytoid dendritic cells constrain Th2 cytokine responses to rhinovirus: a regulatory mechanism with relevance to asthma.

    Science.gov (United States)

    Pritchard, Antonia L; Carroll, Melanie L; Burel, Julie G; White, Olivia J; Phipps, Simon; Upham, John W

    2012-06-15

    Human rhinoviruses (RV) cause only minor illness in healthy individuals, but can have deleterious consequences in people with asthma. This study sought to examine normal homeostatic mechanisms regulating adaptive immunity to RV in healthy humans, focusing on effects of IFN-αβ and plasmacytoid dendritic cells (pDC) on Th2 immune responses. PBMC were isolated from 27 healthy individuals and cultured with RV16 for up to 5 d. In some experiments, IFN-αβ was neutralized using a decoy receptor that blocks IFN signaling, whereas specific dendritic cell subsets were depleted from cultures with immune-magnetic beads. RV16 induced robust expression of IFN-α, IFN-β, multiple IFN-stimulated genes, and T cell-polarizing factors within the first 24 h. At 5 d, the production of memory T cell-derived IFN-γ, IL-10, and IL-13, but not IL-17A, was significantly elevated. Neutralizing the effects of type-I IFN with the decoy receptor B18R led to a significant increase in IL-13 synthesis, but had no effect on IFN-γ synthesis. Depletion of pDC from RV-stimulated cultures markedly inhibited IFN-α secretion, and led to a significant increase in expression and production of the Th2 cytokines IL-5 (p = 0.02), IL-9 (p effect on IFN-γ synthesis. Depletion of CD1c(+) dendritic cells did not alter cytokine synthesis. In healthy humans, pDC and the IFN-αβ they secrete selectively constrain Th2 cytokine synthesis following RV exposure in vitro. This important regulatory mechanism may be lost in asthma; deficient IFN-αβ synthesis and/or pDC dysfunction have the potential to contribute to asthma exacerbations during RV infections.

  1. 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

    2014-06-01

    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.

  2. Dendritic-cell-based immunotherapy evokes potent anti-tumor immune responses in CD105+ human renal cancer stem cells.

    Science.gov (United States)

    Zhang, Xiao-Fei; Weng, De-Sheng; Pan, Ke; Zhou, Zi-Qi; Pan, Qiu-Zhong; Zhao, Jing-Jing; Tang, Yan; Jiang, Shan-Shan; Chen, Chang-Long; Li, Yong-Qiang; Zhang, Hong-Xia; Chang, Alfred E; Wicha, Max S; Zeng, Yi-Xin; Li, Qiao; Xia, Jian-Chuan

    2017-11-01

    Cancer stem cells (CSCs) are responsible for tumor initiation, progression, and resistance to therapeutic agents; they are usually less sensitive to conventional cancer therapies, and could cause tumor relapse. An ideal therapeutic strategy would therefore be to selectively target and destroy CSCs, thereby preventing tumor relapse. The aim of the present study was to evaluate the effectiveness of dendritic cells (DCs) pulsed with antigen derived from CD105+ human renal cell carcinoma (RCC) CSCs against renal cancer cells in vitro and in vivo. We identified "stem-like" characteristics of CD105+ cells in two human RCC cell lines: A498 and SK-RC-39. Loading with cell lysates did not change the characteristics of the DCs. However, DCs loaded with lysates derived from CD105+ CSCs induced more functionally specific active T cells and specific antibodies against CSCs, and clearly depressed the tumor growth in mice. Our results could form the basis for a novel strategy to improve the efficacy of DC-based immunotherapy for human RCC. © 2017 Wiley Periodicals, Inc.

  3. Corticosteroid therapy in regressive autism: a retrospective study of effects on the Frequency Modulated Auditory Evoked Response (FMAER), language, and behavior.

    Science.gov (United States)

    Duffy, Frank H; Shankardass, Aditi; McAnulty, Gloria B; Eksioglu, Yaman Z; Coulter, David; Rotenberg, Alexander; Als, Heidelise

    2014-05-15

    Up to a third of children with Autism Spectrum Disorder (ASD) manifest regressive autism (R-ASD).They show normal early development followed by loss of language and social skills. Absent evidence-based therapies, anecdotal evidence suggests improvement following use of corticosteroids. This study examined the effects of corticosteroids for R-ASD children upon the 4 Hz frequency modulated evoked response (FMAER) arising from language cortex of the superior temporal gyrus (STG) and upon EEG background activity, language, and behavior. An untreated clinical convenience sample of ASD children served as control sample. Twenty steroid-treated R-ASD (STAR) and 24 not-treated ASD patients (NSA), aged 3 - 5 years, were retrospectively identified from a large database. All study participants had two sequential FMAER and EEG studies;Landau-Kleffner syndrome diagnosis was excluded. All subjects' records contained clinical receptive and expressive language ratings based upon a priori developed metrics. The STAR group additionally was scored behaviorally regarding symptom severity as based on the Diagnostic and Statistical Manual IV (DSM-IV) ASD criteria list. EEGs were visually scored for abnormalities. FMAER responses were assessed quantitatively by spectral analysis. Treated and untreated group means and standard deviations for the FMAER, EEG, language, and behavior, were compared by paired t-test and Fisher's exact tests. The STAR group showed a significant increase in the 4 Hz FMAER spectral response and a significant reduction in response distortion compared to the NSA group. Star group subjects' language ratings were significantly improved and more STAR than NSA group subjects showed significant language improvement. Most STAR group children showed significant behavioral improvement after treatment. STAR group language and behavior improvement was retained one year after treatment. Groups did not differ in terms of minor EEG abnormalities. Steroid treatment produced no

  4. Identification of Dynamic Patterns of Speech-Evoked Auditory Brainstem Response Based on Ensemble Empirical Mode Decomposition and Nonlinear Time Series Analysis Methods

    Science.gov (United States)

    Mozaffarilegha, Marjan; Esteki, Ali; Ahadi, Mohsen; Nazeri, Ahmadreza

    The speech-evoked auditory brainstem response (sABR) shows how complex sounds such as speech and music are processed in the auditory system. Speech-ABR could be used to evaluate particular impairments and improvements in auditory processing system. Many researchers used linear approaches for characterizing different components of sABR signal, whereas nonlinear techniques are not applied so commonly. The primary aim of the present study is to examine the underlying dynamics of normal sABR signals. The secondary goal is to evaluate whether some chaotic features exist in this signal. We have presented a methodology for determining various components of sABR signals, by performing Ensemble Empirical Mode Decomposition (EEMD) to get the intrinsic mode functions (IMFs). Then, composite multiscale entropy (CMSE), the largest Lyapunov exponent (LLE) and deterministic nonlinear prediction are computed for each extracted IMF. EEMD decomposes sABR signal into five modes and a residue. The CMSE results of sABR signals obtained from 40 healthy people showed that 1st, and 2nd IMFs were similar to the white noise, IMF-3 with synthetic chaotic time series and 4th, and 5th IMFs with sine waveform. LLE analysis showed positive values for 3rd IMFs. Moreover, 1st, and 2nd IMFs showed overlaps with surrogate data and 3rd, 4th and 5th IMFs showed no overlap with corresponding surrogate data. Results showed the presence of noisy, chaotic and deterministic components in the signal which respectively corresponded to 1st, and 2nd IMFs, IMF-3, and 4th and 5th IMFs. While these findings provide supportive evidence of the chaos conjecture for the 3rd IMF, they do not confirm any such claims. However, they provide a first step towards an understanding of nonlinear behavior of auditory system dynamics in brainstem level.

  5. Wideband Absorbance Outcomes in Newborns: A Comparison With High-Frequency Tympanometry, Automated Brainstem Response, and Transient Evoked and Distortion Product Otoacoustic Emissions.

    Science.gov (United States)

    Aithal, Sreedevi; Kei, Joseph; Driscoll, Carlie; Khan, Asaduzzaman; Swanston, Andrew

    2015-01-01

    The purpose of this study was to evaluate the test performance of wideband absorbance (WBA) in terms of its ability to predict the outer and middle ear status as determined by nine reference standards. Automated auditory brainstem response (AABR), high-frequency (1000 Hz) tympanometry (HFT), transient evoked otoacoustic emission (TEOAE), and distortion product otoacoustic emission (DPOAE) tests were performed on 298 ears (144 right, 154 left) of 192 (108 males, 84 females) neonates with a mean age of 43.7 hours (SD = 21.3, range = 8.3 to 152.2 hr). WBA was measured from 0.25 to 8 kHz using clicks under ambient pressure conditions. Test performance of WBA was assessed in terms of its ability to identify conductive conditions in neonates when compared with nine reference standards (including four single tests and five test batteries) using the receiver operating characteristic analysis. The test performance of WBA against the test battery reference standards was better than that against single test reference standards. The area under the receiver operating characteristic curve reached a high value of 0.78 for HFT + TEOAE + DPOAE and AABR + TEOAE + DPOAE reference standards. Within the ears that passed each of the reference standards, there were no significant differences in WBA. However, for the ears that failed each of the test standards, there were significant differences in WBA. The region between 1 and 4 kHz provided the best discriminability to evaluate the conductive status compared with other frequencies. WBA is a desirable measure of conductive conditions in newborns due to its high performance in classifying ears with conductive loss as determined by the best performing surrogate gold standards (HFT + TEOAE + DPOAE and AABR + TEOAE + DPOAE).

  6. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...... 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...... contralateral to stimulus side and additionally an unexpected 20 Hz activity was observed slightly lateralized in the frontal central region. The gamma phase locking may be a manifestation of early somatosensory feature integration. The analyses suggest that the high frequency activity consists of two distinct...

  7. Choosing health, constrained choices.

    Science.gov (United States)

    Chee Khoon Chan

    2009-12-01

    In parallel with the neo-liberal retrenchment of the welfarist state, an increasing emphasis on the responsibility of individuals in managing their own affairs and their well-being has been evident. In the health arena for instance, this was a major theme permeating the UK government's White Paper Choosing Health: Making Healthy Choices Easier (2004), which appealed to an ethos of autonomy and self-actualization through activity and consumption which merited esteem. As a counterpoint to this growing trend of informed responsibilization, constrained choices (constrained agency) provides a useful framework for a judicious balance and sense of proportion between an individual behavioural focus and a focus on societal, systemic, and structural determinants of health and well-being. Constrained choices is also a conceptual bridge between responsibilization and population health which could be further developed within an integrative biosocial perspective one might refer to as the social ecology of health and disease.

  8. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

  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

    2013-01-01

    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. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...

  11. Inability To Evoke a Long-Lasting Protective Immune Response to Respiratory Syncytial Virus Infection in Mice Correlates with Ineffective Nasal Antibody Responses

    Science.gov (United States)

    Singleton, Richard; Etchart, Nathalie; Hou, Sam; Hyland, Lisa

    2003-01-01

    Long-lasting protective antibody is not normally generated in children following primary respiratory syncytial virus (RSV) infection, frequently leading to reinfection. We used the BALB/c mouse model to examine the role of the nasal-associated lymphoid tissue and the bone marrow in the generation of RSV-specific long-lasting plasma cells, with a view to further understanding the mechanisms responsible for the poorly sustained RSV antibody levels following primary infection. We show here that substantial numbers of RSV-specific plasma cells were generated in the bone marrow following challenge, which were maintained thereafter. In contrast, in the nasal-associated lymphoid tissue, RSV-specific plasma cell numbers waned quickly both after primary infection and after challenge and were not maintained at a higher level after boosting. These data indicate that the inability to generate a robust local mucosal response in the nasal tissues may contribute substantially to the likelihood of subsequent reinfection and that the presence of serum anti-RSV antibody without local protection is not enough to protect against reinfection. PMID:14557616

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

    Directory of Open Access Journals (Sweden)

    Edmir Américo Lourenço

    2008-08-01

    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

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

    Directory of Open Access Journals (Sweden)

    Tainara Milbradt Weich

    2012-10-01

    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

  14. Clinical evaluation of cochlear hearing status in dogs using evoked otoacoustic emissions.

    Science.gov (United States)

    Gonçalves, R; McBrearty, A; Pratola, L; Calvo, G; Anderson, T J; Penderis, J

    2012-06-01

    Evoked otoacoustic emission testing is the preferred test in human patients for sensorineural deafness screening in neonates and cochlear outer hair cell function monitoring in adults. This study evaluated evoked otoacoustic emission testing for cochlear function assessment in dogs within a clinical setting. Two populations of anaesthetised dogs were included. In group 1 the evoked otoacoustic emission response was compared to the brainstem auditory evoked response in 10 dogs having hearing assessment. Group 2 comprised 43 presumed normal dogs, in which the suitability of two types of evoked otoacoustic emissions, transient-evoked and distortion product otoacoustic emissions, were evaluated (brainstem auditory evoked response was not performed in this group). Valid transient-evoked otoacoustic emission and distortion-product otoacoustic emission responses were successfully recorded within the clinical setting and correctly identified deaf and hearing ears. Within presumed healthy dogs, normal otoacoustic emission response was demonstrated in more than 80% of dogs using a single, short distortion-product otoacoustic emission run and in 78% of dogs with valid transient-evoked otoacoustic emission responses using a series of three repeated transient-evoked otoacoustic emission short runs. Transient-evoked otoacoustic emission and distortion-product otoacoustic emission testing provided a rapid, non-invasive frequency-specific assessment of cochlear function. Transient-evoked otoacoustic emission and distortion product otoacoustic emission testing is suitable as a screening procedure to detect loss of cochlear function in dogs, although further investigation is needed. © 2012 British Small Animal Veterinary Association.

  15. Selecting and evoking innovators

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Christiansen, Ellen

    2006-01-01

    prepared for and conducted selection of and collaboration with innovators. The outcome was successful in the sense that the innovators produced excellent foundation for conceptual interaction design by creating mock-ups and explanations incarnating their preferences, attitudes and habits. By referring...... to theories of learning we try to explain how our way of working with selection and evoking of innovators has contributed to this positive result and how our approach to user-driven innovation can be regarded as a way to combine democracy and creativity in design....

  16. Identification of neonatal hearing impairment: evaluation of transient evoked otoacoustic emission, distortion product otoacoustic emission, and auditory brain stem response test performance.

    Science.gov (United States)

    Norton, S J; Gorga, M P; Widen, J E; Folsom, R C; Sininger, Y; Cone-Wesson, B; Vohr, B R; Mascher, K; Fletcher, K

    2000-10-01

    The purpose of this study was to compare the performance of transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), and auditory brain stem responses (ABRs) as tools for identification of neonatal hearing impairment. A total of 4911 infants including 4478 graduates of neonatal intensive care units, 353 well babies with one or more risk factors for hearing loss (Joint Committee on Infant Hearing, 1994) and 80 well babies without risk factor who did not pass one or more neonatal test were targeted as the potential subject pool on which test performance would be assessed. During the neonatal period, they were evaluated using TEOAEs in response to an 80 dB pSPL click, DPOAE responses to two stimulus conditions (L1 = L2 = 75 dB SPL and L1 = 65 dB SPL L2 = 50 dB SPL), and ABR elicited by a 30 dB nHL click. In an effort to describe test performance, these "at-risk" infants were asked to return for behavioral audiologic assessments, using visual reinforcement audiometry (VRA) at 8 to 12 mo corrected age, regardless of neonatal test results. Sixty-four percent of these subjects returned and reliable VRA data were obtained on 95.6% of these returnees. This approach is in contrast to previous studies in which, by necessity, efforts were made to follow only those infants who "failed" the neonatal screening tests. The accuracy of the neonatal measures in predicting hearing status at 8 to 12 mo corrected age was determined. Only those infants who provided reliable, monaural VRA test results were included in the analysis. Separate analyses were performed without regard to intercurrent events (i.e., events between the neonatal and VRA tests that could cause their results to disagree), and then after accounting for the possible influence of intercurrent events such as otitis media and late-onset or progressive hearing loss. Low refer rates were achieved for the stopping criteria used in the present study, especially when a protocol

  17. International Evoked Potentials Symposium

    CERN Document Server

    1980-01-01

    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...

  18. A fuzzy chance-constrained program for unit commitment problem considering demand response, electric vehicle and wind power

    DEFF Research Database (Denmark)

    Zhang, Ning; Hu, Zhaoguang; Han, Xue

    2015-01-01

    commitment model is proposed in this paper considering demand response and electric vehicles, which can promote the exploitation of wind power. On the one hand, demand response and electric vehicles have the feasi- bility to change the load demand curve to solve the mismatch problem. On the other hand...... system operation more eco-friendly and economical....

  19. Resolving electrolayers from VES: A contribution from modeling the electrical response of a tightly constrained alluvial stratigraphy

    Science.gov (United States)

    Mele, M.; Ceresa, N.; Bersezio, R.; Giudici, M.; Inzoli, S.; Cavalli, E.

    2015-08-01

    The reliability of the hydrostratigraphic interpretation of electrostratigraphy derived from ground based, Direct Current resistivity methods is analyzed through the forward modeling of synthetically derived electrostratigraphic layering in a tightly constrained alluvial framework. To this purpose, a high-resolution stratigraphic model of the horizontally-stratified, alluvial aquifers hosted by the Quaternary regressive cycle of the Po plain in Lombardy was elaborated for a small area (1 ha) by correlation of borehole lithostratigraphic data down to 160 m below the ground surface. The stratigraphic model was used to compute 1-D synthetic electrostratigraphy based on the petrophysical relationship linking the bulk electrical resistivity of porous sediments to the coarse-to-fine litho-textural ratio and to the average pore-water electrical conductivity. A synthetic apparent resistivity curve was computed for the 1-D synthetic electrostratigraphy and for a traditional Vertical Electrical Sounding with Schlumberger array and a maximum dipole separation of 300 m. A good agreement was observed with the experimental apparent resistivity curve obtained with a Vertical Electrical Sounding collected in the study area. The comparison of the 1-D synthetic electrostratigraphy with the results obtained by inversion of the experimental data with the linear-digital filter method, under the assumption of electrically homogeneous layers and no lateral resistivity transition, was used to estimate the hydrostratigraphic resolving power of ground-based resistivity data at various depths. Stratigraphic units of different hierarchic orders can be resolved by Direct Current methods at different depths and at different sites. In this specific case study, Vertical Electrical Sounding resolution was comparable to the hierarchy of the genetic depositional systems, corresponding to the rank of the hydrostratigraphic systems.

  20. Vestibular evoked myogenic potential

    Directory of Open Access Journals (Sweden)

    Felipe, Lilian

    2012-01-01

    Full Text Available Introduction: The Vestibular Evoked Myogenic Potential (VEMP is a promising test for the evaluation of the cholic descending vestibular system. This reflex depends of the integrity from the saccular macula, from the inferior vestibular nerve, the vestibular nuclei, the vestibule-spinal tract and effectors muscles. Objective: Perform a systematic review of the pertinent literature by means of database (COCHRANE, MEDLINE, LILACS, CAPES. Conclusion: The clinical application of the VEMP has expanded in the last years, as goal that this exam is used as complementary in the otoneurological evaluation currently used. But, methodological issues must be clarified. This way, this method when combined with the standard protocol, can provide a more widely evaluation from the vestibular system. The standardization of the methodology is fundamental criterion for the replicability and sensibility of the exam.

  1. Lack of TRPM5-Expressing Microvillous Cells in Mouse Main Olfactory Epithelium Leads to Impaired Odor-Evoked Responses and Olfactory-Guided Behavior in a Challenging Chemical Environment

    Science.gov (United States)

    Lemons, Kayla; Aoudé, Imad; Ogura, Tatsuya; Mbonu, Kenechukwu; Matsumoto, Ichiro; Arakawa, Hiroyuki

    2017-01-01

    The mammalian main olfactory epithelium (MOE) modifies its activities in response to changes in the chemical environment. This process is essential for maintaining the functions of the olfactory system and the upper airway. However, mechanisms involved in this functional maintenance, especially those occurring via paracrine regulatory pathways within the multicellular MOE, are poorly understood. Previously, a population of non-neuronal, transient receptor potential M5-expressing microvillous cells (TRPM5-MCs) was identified in the MOE, and the initial characterization of these cells showed that they are cholinergic and responsive to various xenobiotics including odorants at high concentrations. Here, we investigated the role of TRPM5-MCs in maintaining olfactory function using transcription factor Skn-1a knockout (Skn-1a-/-) mice, which lack TRPM5-MCs in the MOE. Under our standard housing conditions, Skn-1a-/- mice do not differ significantly from control mice in odor-evoked electro-olfactogram (EOG) responses and olfactory-guided behaviors, including finding buried food and preference reactions to socially and sexually relevant odors. However, after a 2-wk exposure to high-concentration odor chemicals and chitin powder, Skn-1a-/- mice exhibited a significant reduction in their odor and pheromone-evoked EOG responses. Consequently, their olfactory-guided behaviors were impaired compared with vehicle-exposed Skn-1a-/- mice. Conversely, the chemical exposure did not induce significant changes in the EOG responses and olfactory behaviors of control mice. Therefore, our physiological and behavioral results indicate that TRPM5-MCs play a protective role in maintaining the olfactory function of the MOE. PMID:28612045

  2. Stochastic Security and Risk-Constrained Scheduling for an Autonomous Microgrid with Demand Response and Renewable Energy Resources

    DEFF Research Database (Denmark)

    Vahedipour-Dahraie, Mostafa; Rashidizadeh-Kermani, Homa; Najafi, Hamid Reza

    2017-01-01

    Increasing penetration of intermittent renewable energy sources and the development of advanced information give rise to questions on how responsive loads can be managed to optimise the use of resources and assets. In this context, demand response as a way for modifying the consumption pattern...... of customers can be effectively applied to balance the demand and supply in electricity networks. This study presents a novel stochastic model from a microgrid (MG) operator perspective for energy and reserve scheduling considering risk management strategy. It is assumed that the MG operator can procure energy...... from various sources, including local generating units and demand-side resources to serve the customers. The operator sells electricity to customers under real-time pricing scheme and the customers response to electricity prices by adjusting their loads to reduce consumption costs. The objective...

  3. Data-Constrained Projections of Methane Fluxes in a Northern Minnesota Peatland in Response to Elevated CO2 and Warming

    Science.gov (United States)

    Shuang Ma; Jiang Jiang; Yuanyuan Huang; Zheng Shi; Rachel M. Wilson; Daniel Ricciuto; Stephen D. Sebestyen; Paul J. Hanson; Yiqi Luo

    2017-01-01

    Large uncertainties exist in predicting responses of wetland methane (CH4) fluxes to future climate change. However, sources of the uncertainty have not been clearly identified despite the fact that methane production and emission processes have been extensively explored. In this study, we took advantage of manual CH4 flux...

  4. Music evokes vivid autobiographical memories.

    Science.gov (United States)

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

    2016-08-01

    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.

  5. Adjective metaphors evoke negative meanings.

    Science.gov (United States)

    Sakamoto, Maki; Utsumi, Akira

    2014-01-01

    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.

  6. Adjective metaphors evoke negative meanings.

    Directory of Open Access Journals (Sweden)

    Maki Sakamoto

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Gisiane Munaro

    2010-06-01

    Full Text Available A avaliação otoneurológica consiste em exames para investigação de patologias auditivas e vestibulares, incluindo o potencial evocado de tronco encefálico e a vectoeletronistagmografia. OBJETIVO: Descrever os resultados da avaliação otoneurológica em pacientes com queixas vestibulococleares, normo-ouvintes e com perda auditiva, comparados a grupo-controle. MATERIAL E MÉTODOS: Estudo transversal, retrospectivo, observacional, realizado com 56 pacientes vertiginosos avaliados por audiometria, vectoeletronistagmografia e potencial evocado auditivo de tronco encefálico, divididos em grupo A, 31 pacientes normo-ouvintes, e grupo B, 25 pacientes com perda auditiva, comparados ao grupo-controle constituído por dez voluntários normo-ouvintes assintomáticos. RESULTADOS: Os pacientes dos grupos A e B apresentaram aumento em monobloco das latências absolutas das ondas I, III e V estatisticamente significante, quando comparados ao grupo-controle, embora com valores dentro da normalidade. A ausência da onda I a 80 dBNA foi um achado comum para ambos os grupos e ocorreu em quatro (12,9% sujeitos bilateralmente e em três (9,6% unilateralmente no grupo A e em oito (32% pacientes no grupo B bilateralmente. Nos dois casos em que a vectoeletronistagmografia acusou alteração vestibular central não ocorreram alterações nos parâmetros dos potenciais evocados. CONCLUSÃO: Os pacientes com vertigem, normo-ouvintes e com perda auditiva, apresentaram latências absolutas aumentadas quando comparados a grupo-controleOtoneurological evaluations are based on tests which investigate auditory and vestibular disorders, including brainstem evoked auditory potentials and vecto-electronystagmography. AIM: to describe the results from the otoneurological assessment of patients with vestibulocochlear complaints, normal hearing individuals and patients with hearing loss, and we will compare them to a control group. MATERIALS AND METHODS: Cross

  8. Ocular Vestibular Evoked Myogenic Potentials

    Directory of Open Access Journals (Sweden)

    Felipe, Lilian

    2014-01-01

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

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    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.

  10. Evoked cavernous activity: neuroanatomic implications.

    Science.gov (United States)

    Yilmaz, U; Vicars, B; Yang, C C

    2009-01-01

    We investigated the autonomic innervation of the penis by using evoked cavernous activity (ECA). We recruited seven men with thoracic spinal cord injury (SCI) and sexual dysfunction, and six men who were scheduled to have pelvic surgery (PS), specifically non-nerve-sparing radical cystoprostatectomy. In the PS patients, 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 patient had reproducible hand SSRs. None of these patients had ECA or foot SSRs. All the PS patients 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 with that of the pre-operative period (P>0.05). In conclusion, ECA is absent in men with SCI above the sympathetic outflow to the genitalia. In men, after radical pelvic surgery, ECA is preserved, indicating the preservation of sympathetic fibers.

  11. Do ambient urban odors evoke basic emotions?

    Directory of Open Access Journals (Sweden)

    Sandra Theresia Weber-Glass

    2014-04-01

    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.

  12. 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.

  13. Evoked emotions predict food choice.

    Science.gov (United States)

    Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

    2014-01-01

    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.

  14. Music-Evoked Emotions-Current Studies.

    Science.gov (United States)

    Schaefer, Hans-Eckhardt

    2017-01-01

    The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

  15. 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

    2006-07-01

    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.

  16. 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

    2012-01-01

    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...

  17. Electrical stimulation of the dorsal nerve of the penis evokes reflex tonic erections of the penile body and reflex ejaculatory responses in the spinal rat.

    Science.gov (United States)

    Pescatori, E S; Calabro, A; Artibani, W; Pagano, F; Triban, C; Italiano, G

    1993-03-01

    An animal model using the spinal rat was characterized. Electrical stimulation of the dorsal nerve of the penis elicited reflex tonic erections of the penile body and reflex bulbospongiosus muscle activity, flips and ejaculations. The tonic erections of the penile body are independent from contractions of the bulbospongiosus muscle and appear to be the result of a neurovascular process. Our observations suggest that reflex bulbospongiosus muscle activity, flips and ejaculations are a single complex reflex response, which we define as reflex ejaculatory response. Two parameters predicted the occurrence and type of reflex response. The visualization of bulbospongiosus muscle activity during surgical isolation of the dorsal nerve of the penis was sufficient to anticipate the elicitability of reflex ejaculatory responses. The latter, together with a systemic systolic pressure > or = 73 mmHg., warranted the elicitability of reflex tonic erections. The similarities found in the physiology of rat tonic penile body erections and of human erections make this model promising for further elucidation of sexual function. Moreover, the present model may prove useful for the investigation of neurogenic erectile dysfunction, and of neurogenic ejaculatory disorders.

  18. 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

    2015-03-01

    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.

  19. Fear-Mongering or Fact-Driven? Illuminating the Interplay of Objective Risk and Emotion-Evoking Form in the Response to Epidemic News.

    Science.gov (United States)

    Klemm, Celine; Hartmann, Tilo; Das, Enny

    2017-10-23

    This study examined the veracity of the common assumption that news coverage of epidemic outbreaks spawns heightened fears and risk perceptions. An online experiment with 1,324 participants investigated the interplay of the form of news coverage (factual/emotion-laden) and key aspects of actual risk (low/high vulnerability, low/high severity) on audience responses. Participants read one of eight versions of a newspaper article followed by measures on risk perceptions, negative affect, behavioral intentions, and perceived sensationalism. Risk perceptions and fear were primarily driven by objective risk characteristics, whereas emotion-laden news form only increased perceptions of disease severity, not of fear or personal vulnerability.

  20. Evoked Emotions Predict Food Choice

    NARCIS (Netherlands)

    Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

    2014-01-01

    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.

  1. Human auditory evoked potentials. II - Effects of attention

    Science.gov (United States)

    Picton, T. W.; Hillyard, S. A.

    1974-01-01

    Attention directed toward auditory stimuli, in order to detect an occasional fainter 'signal' stimulus, caused a substantial increase in the N1 (83 msec) and P2 (161 msec) components of the auditory evoked potential without any change in preceding components. This evidence shows that human auditory attention is not mediated by a peripheral gating mechanism. The evoked response to the detected signal stimulus also contained a large P3 (450 msec) wave that was topographically distinct from the preceding components. This late positive wave could also be recorded in response to a detected omitted stimulus in a regular train and therefore seemed to index a stimulus-independent perceptual decision process.

  2. 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)

    2012-06-15

    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.

  3. Ocular vestibular evoked myogenic potentials in response to air-conducted 500 Hz short tones: Effect of stimulation procedure (monaural or binaural), age and gender.

    Science.gov (United States)

    Versino, Maurizio; Colnaghi, Silvia; Ranzani, Marina; Alloni, Roberto; Bolis, Carlotta; Sacco, Simone; Moglia, Arrigo; Callieco, Roberto

    2015-01-01

    The ocular vestibular myogenic potentials (oVEMP) can be elicited by monaural air-conducted sound stimulation, and are usually recorded from the contralateral eye. In clinical setting a binaural stimulation would save time and require less effort from the subjects. We evaluated the differences between monaural and binaural stimulation, and the possible effect of age and gender on oVEMP parameters. Air-conducted oVEMP were recorded by binaural and by monaural stimulation in a group of 54 normal subjects, aged from 12 to 83 years, and in 50 vestibular patients. From each side, we measured the latency of the N1 component, and the peak-to-peak N1-P1 amplitude. For both parameters we also computed the asymmetry ratio. In normal subjects binaural stimulation produced slightly larger responses than monaural stimulation; detectability, latency and amplitude ratio were the same for the two techniques. We found no differences related to gender, and the age-induced amplitude decline was likely to be negligible.oVEMP recorded not in an acute phase of their disorder, proved to be abnormal in about 20% of the patients, and the normal or abnormal findings obtained either with monaural or with binaural stimulation were always concordant. The oVEMP obtained after binaural and monaural stimulation are very similar, and they are largely independent from age and gender.

  4. cGMP-Dependent Protein Kinase Inhibition Extends the Upper Temperature Limit of Stimulus-Evoked Calcium Responses in Motoneuronal Boutons of Drosophila melanogaster Larvae.

    Science.gov (United States)

    Krill, Jennifer L; Dawson-Scully, Ken

    2016-01-01

    While the mammalian brain functions within a very narrow range of oxygen concentrations and temperatures, the fruit fly, Drosophila melanogaster, has employed strategies to deal with a much wider range of acute environmental stressors. The foraging (for) gene encodes the cGMP-dependent protein kinase (PKG), has been shown to regulate thermotolerance in many stress-adapted species, including Drosophila, and could be a potential therapeutic target in the treatment of hyperthermia in mammals. Whereas previous thermotolerance studies have looked at the effects of PKG variation on Drosophila behavior or excitatory postsynaptic potentials at the neuromuscular junction (NMJ), little is known about PKG effects on presynaptic mechanisms. In this study, we characterize presynaptic calcium ([Ca2+]i) dynamics at the Drosophila larval NMJ to determine the effects of high temperature stress on synaptic transmission. We investigated the neuroprotective role of PKG modulation both genetically using RNA interference (RNAi), and pharmacologically, to determine if and how PKG affects presynaptic [Ca2+]i dynamics during hyperthermia. We found that PKG activity modulates presynaptic neuronal Ca2+ responses during acute hyperthermia, where PKG activation makes neurons more sensitive to temperature-induced failure of Ca2+ flux and PKG inhibition confers thermotolerance and maintains normal Ca2+ dynamics under the same conditions. Targeted motoneuronal knockdown of PKG using RNAi demonstrated that decreased PKG expression was sufficient to confer thermoprotection. These results demonstrate that the PKG pathway regulates presynaptic motoneuronal Ca2+ signaling to influence thermotolerance of presynaptic function during acute hyperthermia.

  5. In vivo optical microprobe imaging for intracellular Ca2+ dynamics in response to dopaminergic signaling in deep brain evoked by cocaine

    Science.gov (United States)

    Luo, Zhongchi; Pan, Yingtian; Du, Congwu

    2012-02-01

    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.

  6. Evolutionary constrained optimization

    CERN Document Server

    Deb, Kalyanmoy

    2015-01-01

    This book makes available a self-contained collection of modern research addressing the general constrained optimization problems using evolutionary algorithms. Broadly the topics covered include constraint handling for single and multi-objective optimizations; penalty function based methodology; multi-objective based methodology; new constraint handling mechanism; hybrid methodology; scaling issues in constrained optimization; design of scalable test problems; parameter adaptation in constrained optimization; handling of integer, discrete and mix variables in addition to continuous variables; application of constraint handling techniques to real-world problems; and constrained optimization in dynamic environment. There is also a separate chapter on hybrid optimization, which is gaining lots of popularity nowadays due to its capability of bridging the gap between evolutionary and classical optimization. The material in the book is useful to researchers, novice, and experts alike. The book will also be useful...

  7. Music-Evoked Emotions—Current Studies

    Directory of Open Access Journals (Sweden)

    Hans-Eckhardt Schaefer

    2017-11-01

    Full Text Available The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI and positron emission tomography (PET, which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG, event-related brain potentials (ERP, magnetoencephalography (MEG, skin conductance response (SCR, finger temperature, and goose bump development (piloerection can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

  8. Music-Evoked Emotions—Current Studies

    Science.gov (United States)

    Schaefer, Hans-Eckhardt

    2017-01-01

    The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields. PMID:29225563

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

    Science.gov (United States)

    Taruffi, Liila; Koelsch, Stefan

    2014-01-01

    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.

  10. 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.

  11. The Paradox of Music-Evoked Sadness: An Online Survey

    Science.gov (United States)

    Taruffi, Liila; Koelsch, Stefan

    2014-01-01

    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. PMID:25330315

  12. Evoked Emotions Predict Food Choice

    OpenAIRE

    Dalenberg, Jelle R.; Swetlana Gutjar; Gert J Ter Horst; Kees de Graaf; Renken, Remco J.; Gerry Jager

    2014-01-01

    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 ...

  13. EVOKED CAVERNOUS ACTIVITY: NEUROANATOMIC IMPLICATIONS

    OpenAIRE

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

    2009-01-01

    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 t...

  14. Model of evoked rabbit phonation.

    Science.gov (United States)

    Ge, Ping Jiang; French, Lesley C; Ohno, Tsunehisa; Zealear, David L; Rousseau, Bernard

    2009-01-01

    We describe a method for eliciting phonation in an in vivo rabbit preparation using low-frequency, bipolar pulsed stimulation of the cricothyroid muscles with airflow delivered to the glottis. Ten New Zealand White breeder rabbits weighing 3 to 5 kg were used in this study. The cricothyroid muscles were isolated bilaterally, and separate pairs of anode-cathode hooked-wire electrodes were inserted into each muscle. A Grass S-88 stimulator and 2 constant-current PSIU6 isolation units were used to deliver bipolar square wave pulses to each cricothyroid muscle, with airflow delivered to the glottis through a cuffed endotracheal tube. Phonation was evoked with a 50-Hz, 4-mA stimulus train of 1-ms pulses delivered to each cricothyroid muscle. The pulse trains were on for 2 seconds and were repeated every 5 seconds over a period of 180 minutes. Airflow was delivered at 143 cm3/s, producing phonation measuring 71 to 85 dB sound pressure level. Evoked phonation is feasible in rabbits by use of bipolar stimulation of the cricothyroid muscles with airflow delivered to the glottis. The in vivo rabbit preparation described may provide a useful small animal option for studies of evoked phonation. From the level and consistency of the adduction observed, we hypothesize that current spreading to the underlying adductor muscles and nerves resulted in neural pathway involvement beyond discrete activation of the cricothyroid muscle, providing sufficient approximation of the vocal folds for phonation.

  15. Sex and Ear Differences in Spontaneous and Click-Evoked Otoacoustic Emissions in Young Adults

    Science.gov (United States)

    Snihur, Adrian W. K.; Hampson, Elizabeth

    2011-01-01

    Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in…

  16. One Year of Musical Training Affects Development of Auditory Cortical-Evoked Fields in Young Children

    Science.gov (United States)

    Fujioka, Takako; Ross, Bernhard; Kakigi, Ryusuke; Pantev, Christo; Trainor, Laurel J.

    2006-01-01

    Auditory evoked responses to a violin tone and a noise-burst stimulus were recorded from 4- to 6-year-old children in four repeated measurements over a 1-year period using magnetoencephalography (MEG). Half of the subjects participated in musical lessons throughout the year; the other half had no music lessons. Auditory evoked magnetic fields…

  17. Single-sweep spectral analysis of contact heat evoked potentials

    DEFF Research Database (Denmark)

    Hansen, Tine M; Graversen, Carina; Frøkjaer, Jens B

    2015-01-01

    AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single-sweep ch...

  18. New perspectives on vestibular evoked myogenic potentials.

    Science.gov (United States)

    Rosengren, Sally M; Kingma, Herman

    2013-02-01

    Although the vestibular evoked myogenic potential (VEMP) measured from the cervical muscles (cVEMP, cervical VEMP) is well described and has documented clinical utility, its analogue recorded from the extraocular muscles (oVEMP, ocular VEMP) has been described only recently and is currently emerging as an additional test of otolith function. This review will, therefore, summarize recent developments in VEMP research with a focus on the oVEMP. Recent studies suggest that the oVEMP is produced by otolith afferents in the superior vestibular nerve division, whereas the cVEMP evoked by sound is thought to be an inferior vestibular nerve reflex. Correspondingly, the oVEMP correlates better with caloric and subjective visual vertical tests than sound-cVEMPs. cVEMPs are more complicated than often thought, as shown by the presence of crossed responses and conflicting results of recent vibration studies. Altered inner ear mechanics produced by the vestibular diseases superior semicircular canal dehiscence and Ménière's disease lead to changes in the preferred frequency of the oVEMP and cVEMP. The oVEMP provides complementary diagnostic information to the cVEMP and is likely to be a useful addition to the diagnostic test battery in neuro-otology.

  19. Healthy Architecture! Can environments evoke emotional responses?

    Science.gov (United States)

    Roessler, Kirsten Kaya

    2012-06-05

    We find environmental psychology at the intersection between architecture and psychology. This article discusses the ways in which individuals are affected by architecture, departing from an early source on the psychology of architecture and taking three architectural examples as illustrations: a public place in Berlin, a health environment in Sweden, and a fitness centre in Denmark. Each of these architectural examples creates what might be called its own psychological emotions, and these are analysed and discussed using a psychodynamic and existential attempt to understand the interrelationship between individuals and spatial reality. A health oriented existential approach is used as a methodological basis to conceptualise the psychological effects of various forms of architecture.

  20. Healthy Architecture! Can environments evoke emotional responses?

    OpenAIRE

    Roessler, Kirsten Kaya

    2012-01-01

    We find environmental psychology at the intersection between architecture and psychology. This article discusses the ways in which individuals are affected by architecture, departing from an early source on the psychology of architecture and taking three architectural examples as illustrations: a public place in Berlin, a health environment in Sweden, and a fitness centre in Denmark. Each of these architectural examples creates what might be called its own psychological emotions, and these ar...

  1. Minimal constrained supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Cribiori, N. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Dall' Agata, G., E-mail: dallagat@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Farakos, F. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Porrati, M. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

    2017-01-10

    We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.

  2. Constrained superfields in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Dall’Agata, Gianguido; Farakos, Fotis [Dipartimento di Fisica ed Astronomia “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy)

    2016-02-16

    We analyze constrained superfields in supergravity. We investigate the consistency and solve all known constraints, presenting a new class that may have interesting applications in the construction of inflationary models. We provide the superspace Lagrangians for minimal supergravity models based on them and write the corresponding theories in component form using a simplifying gauge for the goldstino couplings.

  3. Minimal constrained supergravity

    Directory of Open Access Journals (Sweden)

    N. Cribiori

    2017-01-01

    Full Text Available We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.

  4. Achieving Presence through Evoked Reality

    Science.gov (United States)

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

    2013-01-01

    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.” PMID:23550234

  5. RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

    Directory of Open Access Journals (Sweden)

    A. A. Sazgar

    2006-05-01

    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.

  6. Cyclic AMP directs inositol (1,4,5)-trisphosphate-evoked Ca2+ signalling to different intracellular Ca2+ stores

    OpenAIRE

    Tovey, Stephen C.; Taylor, Colin W.

    2013-01-01

    Cholesterol depletion reversibly abolishes carbachol-evoked Ca2+ release from inositol (1,4,5)-trisphosphate (IP3)-sensitive stores, without affecting the distribution of IP3 receptors (IP3R) or endoplasmic reticulum, IP3 formation or responses to photolysis of caged IP3. Receptors that stimulate cAMP formation do not alone evoke Ca2+ signals, but they potentiate those evoked by carbachol. We show that these potentiated signals are entirely unaffected by cholesterol depletion and that, within...

  7. Exploring Constrained Creative Communication

    DEFF Research Database (Denmark)

    Sørensen, Jannick Kirk

    2017-01-01

    between communicative constrains and participants’ perception of dialogue and creativity is examined. Four batches of students preparing for forming semester project groups were conducted and documented. Students were asked to create an unspecified object without any exchange of communication except......Creative collaboration via online tools offers a less ‘media rich’ exchange of information between participants than face-to-face collaboration. The participants’ freedom to communicate is restricted in means of communication, and rectified in terms of possibilities offered in the interface. How do...

  8. Establishing an evoked-potential vision-tracking system

    Science.gov (United States)

    Skidmore, Trent A.

    1991-01-01

    This paper presents experimental evidence to support the feasibility of an evoked-potential vision-tracking system. The topics discussed are stimulator construction, verification of the photic driving response in the electroencephalogram, a method for performing frequency separation, and a transient-analysis example. The final issue considered is that of object multiplicity (concurrent visual stimuli with different flashing rates). The paper concludes by discussing several applications currently under investigation.

  9. Comparison of clinical and evoked pain measures in fibromyalgia.

    Science.gov (United States)

    Harris, Richard E; Gracely, Richard H; McLean, Samuel A; Williams, David A; Giesecke, Thorsten; Petzke, Frank; Sen, Ananda; Clauw, Daniel J

    2006-07-01

    Evoked pain measures such as tender point count and dolorimetry are often used to determine tenderness in studies of fibromyalgia (FM). However, these measures frequently do not improve in clinical trials and are known to be influenced by factors other than pain such as distress and expectancy. The purpose of this investigation was to determine whether evoked pain paradigms that present pressure stimuli in a random fashion (eg, Multiple Random Staircase [MRS]) would track with clinical pain improvement in patients with FM better than traditional measures. Sixty-five subjects enrolled in a randomized clinical trial of acupuncture were observed longitudinally. Clinical pain was measured on a 101-point numerical rating scale (NRS) and the Short Form McGill Pain Questionnaire (SF-MPQ), whereas evoked pressure sensitivity was assessed via manual tender point count, dolorimetry, and MRS methods. Improvements in clinical pain and evoked pain were assessed irrespective of group assignment. Improvement was seen in clinical pain during the course of the trial as measured by both NRS (P = .032) and SF-MPQ (P = .001). The MRS was the only evoked pain measure to improve correspondingly with treatment (MRS, P = .001; tender point count and dolorimeter, P > .05). MRS change scores were correlated with changes in NRS pain ratings (P = .003); however, this association was not stronger than tender point or dolorimetry correlations with clinical pain improvement (P > .05). Pain sensitivity as assessed by random paradigms was associated with improvements in clinical FM pain. Sophisticated pain testing paradigms might be responsive to change in clinical trials. Trials in fibromyalgia often use both clinical and experimental methods of pain assessment; however, these two outcomes are often poorly correlated. We explore the relationship between changes in clinical and experimental pain within FM patients. Pressure pain testing that applies stimuli in a random order is associated with

  10. Visual evoked potentials in patients after methanol poisoning.

    Science.gov (United States)

    Urban, Pavel; Zakharov, Sergey; Diblík, Pavel; Pelclová, Daniela; Ridzoň, Petr

    2016-01-01

    We report the results of the visual evoked potentials (VEP) examination in patients after severe poisoning by methanol. 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. 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. 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. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  11. Modeling the microstructural evolution during constrained sintering

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Frandsen, Henrik Lund; Pryds, Nini

    2014-01-01

    A numerical model able to simulate solid state constrained sintering is presented. The model couples an existing kinetic Monte Carlo (kMC) model for free sintering with a finite element model (FEM) for calculating stresses on a microstructural level. The microstructural response to the local stress...

  12. Modeling the Microstructural Evolution During Constrained Sintering

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Frandsen, Henrik Lund; Pryds, Nini

    2015-01-01

    A numerical model able to simulate solid-state constrained sintering is presented. The model couples an existing kinetic Monte Carlo model for free sintering with a finite element model (FEM) for calculating stresses on a microstructural level. The microstructural response to the local stress...

  13. Modeling the microstructural evolution during constrained sintering

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Frandsen, Henrik Lund; Tikare, V.

    A numerical model able to simulate solid state constrained sintering of a powder compact is presented. The model couples an existing kinetic Monte Carlo (kMC) model for free sintering with a finite element (FE) method for calculating stresses on a microstructural level. The microstructural response...

  14. Sex differences in pudendal somatosensory evoked potentials.

    Science.gov (United States)

    Pelliccioni, G; Piloni, V; Sabbatini, D; Fioravanti, P; Scarpino, O

    2014-06-01

    Somatosensory evoked potentials (SEPs) of the pudendal nerve are a well-established diagnostic tool for the evaluation of pelvic floor disorders. However, the possible influence of sex differences on response latencies has not been established yet. The aim of this study was to standardize the procedures and to evaluate possible effects of gender differences on anal and penile/clitoral SEPs. The anal and dorsal penile/clitoral SEPs were recorded in 84 healthy subjects (40 males and 44 females; mean age 47.9 ± 16.6 years, range 16-81 years; mean height 168.3 ± 20.3 cm, range 155-187 cm). Pudendal SEPs were evoked with a bipolar surface electrode stimulating the clitoris or the base of the penis and the anal orifice and recorded using scalp electrodes. The latency of the first positive component (P1) was measured. The effect and possible interaction of (a) stimulation site and (b) gender on the two variables was explored by multivariate analysis of variance (MANOVA). The examination was well tolerated and a reproducible waveform of sufficient quality was obtained in all the subjects examined. In the female subjects, a mean cortical P1 latency of 37.0 ± 2.6 and 36.4 ± 3.2 ms for anal and clitoral stimulation, respectively, was found. In the male subjects, the cortical latencies were 38.0 ± 3.5 ms for the anal stimulation and 40.2 ± 3.7 ms for the penile stimulation. At MANOVA, a statistically significant main effect of stimulation site and gender as well as a significant interaction between the two variables was found. Anal and dorsal penile/clitoral SEPs represent a well-tolerated and reproducible method to assess the functional integrity of the sensory pathways in male and female subjects. Obtaining sex-specific reference data, by individual electrophysiological testing, is highly recommended because of significant latency differences between males and females, at least as far as penile/clitoral responses are concerned.

  15. [Present situation and development of ocular vestibular-evoked myogenic potential].

    Science.gov (United States)

    Hu, Juan; Xu, Min; Zhang, Qing

    2013-04-01

    Myogenic potentials evoked by air conducted sound (ACS), bone conducted vibration (BCV) or galvanic pulses can be recorded with surface electrodes over contracted muscles. These myogenic potentials are of vestibular origin (utricle and saccule) and so these potentials are called vestibular evoked myogenic potentials (VEMPs). Since the vestibular system has projections to many muscle systems, there are many such VEMPs. In this review, we discuss the generated origin, response pathway, waveform characteristics and clinical application of ocular vestibular-evoked myogenic potential (oVEMP).

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

    Directory of Open Access Journals (Sweden)

    Nicole Alexandra Himmelstoss

    2015-05-01

    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.

  17. Sharp spatially constrained inversion

    DEFF Research Database (Denmark)

    Vignoli, Giulio G.; Fiandaca, Gianluca G.; Christiansen, Anders Vest C A.V.C.

    2013-01-01

    We present sharp reconstruction of multi-layer models using a spatially constrained inversion with minimum gradient support regularization. In particular, its application to airborne electromagnetic data is discussed. Airborne surveys produce extremely large datasets, traditionally inverted...... by using smoothly varying 1D models. Smoothness is a result of the regularization constraints applied to address the inversion ill-posedness. The standard Occam-type regularized multi-layer inversion produces results where boundaries between layers are smeared. The sharp regularization overcomes...... inversions are compared against classical smooth results and available boreholes. With the focusing approach, the obtained blocky results agree with the underlying geology and allow for easier interpretation by the end-user....

  18. Transient evoked otoacoustic emissions testing for screening of sensorineural deafness in puppies

    OpenAIRE

    McBrearty, A; Penderis, J

    2011-01-01

    Background: Transient evoked otoacoustic emissions (TEOAE) are widely used for human neonatal deafness screening, but have not been reported for clinical use in dogs. \\ud \\ud Hypothesis/Objectives: To investigate the feasibility of TEOAE testing in conscious puppies and the ability of TEOAE testing to correctly identify deaf and hearing ears, as defined by brainstem auditory evoked response (BAER). \\ud \\ud Animals: Forty puppies from 10 litters. \\ud \\ud Methods: Prospective study on puppies p...

  19. Evoked potentials in neuroinfections in children

    Directory of Open Access Journals (Sweden)

    V. N. Komantsev

    2013-01-01

    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.

  20. Visual Evoked Potentials in Rett Syndrome

    Directory of Open Access Journals (Sweden)

    J. Gordon Millichap

    2015-11-01

    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.

  1. [Motor evoked potentials of the perineal floor. Preliminary results].

    Science.gov (United States)

    Opsomer, R J; Van Cangh, P J; Humblet, Y; Abi Aad, A; Rossini, P M

    1989-01-01

    Neuromotor pathways from the brain to the pelvic floor have been poorly documented. The recent development of Motor Evoked Potentials may well fill this gap in our basic knowledge. Our technique consists of transcutaneous stimulation of the motor cortex and sacral roots with a magnetic device while recording the evoked response from the bulbocavernosus muscle and anal sphincter. Cortical stimulation is performed first at rest and then during voluntary contraction of the examined muscles ("facilitation" procedure). Sacral root stimulation is performed at rest. Stimulation at 2 different levels allows measurement of the total transit time (brain to muscle transit time) and the peripheral transit time (sacral roots to muscle). By subtracting the latter from the former, the central transit time (brain to sacral roots) is obtained. The technique is painless, and to our knowledge no side effects have been reported. The authors present the preliminary results of this new technique.

  2. Automatic classification of visual evoked potentials based on wavelet decomposition

    Science.gov (United States)

    Stasiakiewicz, Paweł; Dobrowolski, Andrzej P.; Tomczykiewicz, Kazimierz

    2017-04-01

    Diagnosis of part of the visual system, that is responsible for conducting compound action potential, is generally based on visual evoked potentials generated as a result of stimulation of the eye by external light source. The condition of patient's visual path is assessed by set of parameters that describe the time domain characteristic extremes called waves. The decision process is compound therefore diagnosis significantly depends on experience of a doctor. The authors developed a procedure - based on wavelet decomposition and linear discriminant analysis - that ensures automatic classification of visual evoked potentials. The algorithm enables to assign individual case to normal or pathological class. The proposed classifier has a 96,4% sensitivity at 10,4% probability of false alarm in a group of 220 cases and area under curve ROC equals to 0,96 which, from the medical point of view, is a very good result.

  3. Visual evoked potential study in slow learners.

    Science.gov (United States)

    Khaliq, Farah; Anjana, Yumnam; Vaney, Neelam

    2009-01-01

    Slow learners are individuals with low achievement and comparably low IQ scores. It may be a symptom reflecting a larger underlying problem in them. Sensory neural processing of visual information can be one of the contributory factors for their underachievement. The present study was undertaken to examine the integrity and function of visual pathway by means of Visual Evoked Potential (VEP). Pattern reversal VEP was performed on seventeen slow learners. Fifteen age and sex matched children with good school performance and normal IQ were taken as controls. There was significant prolongation of N75 component of VEP in slow learners. The latencies of P100 and N145 were also increased but could not reach the level of significance. Our findings are suggestive of the presence of a weaker VEP response in slow learners indicative of a deficit early in the visual processing. There is some abnormality in the geniculate afferents to V1 which is consistent with a defect in the magnocellular pathway at the level of Visual Area 1 or earlier.

  4. The neonatal development of the light flash visual evoked potential.

    Science.gov (United States)

    Kraemer, M; Abrahamsson, M; Sjöström, A

    1999-01-01

    To follow visual development longitudinally in the normal neonate using the flash visual evoked potential (VEP) and to find indications for a relationship between potential development and visual development. Twenty healthy infants, born at term, were included in the study. Flash and patterned flash VEPs were used. The first VEP was recorded the day of birth or just postnatally, and succeeding recordings were performed the following weeks and months. The data revealed different types of VEP in the neonatal period suggesting great variability in visual function on the day of birth. In the early development a potential of long latency and duration preceded the development of a more compound potential of shorter latency. The two types of responses seemed to coalesce during early development; the first late response was attenuated and was eventually integrated in the more mature VEP. At approximately five weeks of age changes in the VEP were simultaneous with the development of responsive smiling and another visual behaviour of the infants. The results showed many similarities between the VEP development in infants and in immature animals. In developing animals geniculo-cortical and extra-geniculate visual afferent pathways evoke two types of VEPs similar to those recorded in the present study. The early responses were also similar to previous recordings from children with lesions in the geniculo-striatal pathway or primary cortex. Our interpretation of the results was that the human VEP also consists of responses evoked by afferents running both in geniculo-cortical and extra-geniculate pathways and that the two types of responses could be separated in the VEP in the neonatal period. These findings are important for our understanding of conditions with a delay in visual maturation, for example intracranial haemorrhages, hydrocephalus, pre/dys-maturity and 'idiopathic' delayed visual maturation.

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

    Directory of Open Access Journals (Sweden)

    Rachel S. Herz

    2016-07-01

    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.

  6. Clinical Evaluation of the Vestibular Nerve Using Vestibular Evoked Myogenic Potentials.

    Science.gov (United States)

    Bogle, Jamie M

    2018-01-01

    Vestibular evoked myogenic potentials are currently the most clinically accessible method to evaluate the otolith reflex pathways. These responses provide unique information regarding the status of the utriculo-ocular and sacculo-collic reflex pathways, information that has previously been unavailable. Vestibular evoked myogenic potentials are recorded from tonically contracted target muscles known to be innervated by these respective otolith organs. Diagnosticians can use vestibular evoked myogenic potentials to better evaluate the overall integrity of the inner ear and neural pathways; however, there are specific considerations for each otolith reflex protocol. In addition, specific patient populations may require protocol variations to better evaluate atypical function of the inner ear organs, vestibular nerve transmission, or subsequent reflex pathways. This is a review of the clinical application and interpretation of cervical and ocular vestibular evoked myogenic potentials.

  7. Perceptual learning of acoustic noise generates memory-evoked potentials.

    Science.gov (United States)

    Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel

    2015-11-02

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Characterization of Motor and Somatosensory Evoked Potentials in the Yucatan Micropig Using Transcranial and Epidural Stimulation.

    Science.gov (United States)

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

    2017-09-15

    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.

  9. Awareness during anaesthesia for surgery requiring evoked potential monitoring: A pilot study

    Directory of Open Access Journals (Sweden)

    Pritish J Korula

    2017-01-01

    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

  10. A retinoraphe projection regulates serotonergic activity and looming-evoked defensive behaviour.

    Science.gov (United States)

    Huang, Lu; Yuan, Tifei; Tan, Minjie; Xi, Yue; Hu, Yu; Tao, Qian; Zhao, Zhikai; Zheng, Jiajun; Han, Yushui; Xu, Fuqiang; Luo, Minmin; Sollars, Patricia J; Pu, Mingliang; Pickard, Gary E; So, Kwok-Fai; Ren, Chaoran

    2017-03-31

    Animals promote their survival by avoiding rapidly approaching objects that indicate threats. In mice, looming-evoked defensive responses are triggered by the superior colliculus (SC) which receives direct retinal inputs. However, the specific neural circuits that begin in the retina and mediate this important behaviour remain unclear. Here we identify a subset of retinal ganglion cells (RGCs) that controls mouse looming-evoked defensive responses through axonal collaterals to the dorsal raphe nucleus (DRN) and SC. Looming signals transmitted by DRN-projecting RGCs activate DRN GABAergic neurons that in turn inhibit serotoninergic neurons. Moreover, activation of DRN serotoninergic neurons reduces looming-evoked defensive behaviours. Thus, a dedicated population of RGCs signals rapidly approaching visual threats and their input to the DRN controls a serotonergic self-gating mechanism that regulates innate defensive responses. Our study provides new insights into how the DRN and SC work in concert to extract and translate visual threats into defensive behavioural responses.

  11. Power-constrained supercomputing

    Science.gov (United States)

    Bailey, Peter E.

    As we approach exascale systems, power is turning from an optimization goal to a critical operating constraint. With power bounds imposed by both stakeholders and the limitations of existing infrastructure, achieving practical exascale computing will therefore rely on optimizing performance subject to a power constraint. However, this requirement should not add to the burden of application developers; optimizing the runtime environment given restricted power will primarily be the job of high-performance system software. In this dissertation, we explore this area and develop new techniques that extract maximum performance subject to a particular power constraint. These techniques include a method to find theoretical optimal performance, a runtime system that shifts power in real time to improve performance, and a node-level prediction model for selecting power-efficient operating points. We use a linear programming (LP) formulation to optimize application schedules under various power constraints, where a schedule consists of a DVFS state and number of OpenMP threads for each section of computation between consecutive message passing events. We also provide a more flexible mixed integer-linear (ILP) formulation and show that the resulting schedules closely match schedules from the LP formulation. Across four applications, we use our LP-derived upper bounds to show that current approaches trail optimal, power-constrained performance by up to 41%. This demonstrates limitations of current systems, and our LP formulation provides future optimization approaches with a quantitative optimization target. We also introduce Conductor, a run-time system that intelligently distributes available power to nodes and cores to improve performance. The key techniques used are configuration space exploration and adaptive power balancing. Configuration exploration dynamically selects the optimal thread concurrency level and DVFS state subject to a hardware-enforced power bound

  12. Characterization of music-evoked autobiographical memories.

    Science.gov (United States)

    Janata, Petr; Tomic, Stefan T; Rakowski, Sonja K

    2007-11-01

    Despite music's prominence in Western society and its importance to individuals in their daily lives, very little is known about the memories and emotions that are often evoked when hearing a piece of music from one's past. We examined the content of music-evoked autobiographical memories (MEAMs) using a novel approach for selecting stimuli from a large corpus of popular music, in both laboratory and online settings. A set of questionnaires probed the cognitive and affective properties of the evoked memories. On average, 30% of the song presentations evoked autobiographical memories, and the majority of songs also evoked various emotions, primarily positive, that were felt strongly. The third most common emotion was nostalgia. Analyses of written memory reports found both general and specific levels of autobiographical knowledge to be represented, and several social and situational contexts for memory formation were common across many memories. The findings indicate that excerpts of popular music serve as potent stimuli for studying the structure of autobiographical memories.

  13. Brain correlates of music-evoked emotions.

    Science.gov (United States)

    Koelsch, Stefan

    2014-03-01

    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.

  14. Evoking prescribed spike times in stochastic neurons

    Science.gov (United States)

    Doose, Jens; Lindner, Benjamin

    2017-09-01

    Single cell stimulation in vivo is a powerful tool to investigate the properties of single neurons and their functionality in neural networks. We present a method to determine a cell-specific stimulus that reliably evokes a prescribed spike train with high temporal precision of action potentials. We test the performance of this stimulus in simulations for two different stochastic neuron models. For a broad range of parameters and a neuron firing with intermediate firing rates (20-40 Hz) the reliability in evoking the prescribed spike train is close to its theoretical maximum that is mainly determined by the level of intrinsic noise.

  15. Whole person-evoked fMRI activity patterns in human fusiform gyrus are accurately modeled by a linear combination of face- and body-evoked activity patterns.

    Science.gov (United States)

    Kaiser, Daniel; Strnad, Lukas; Seidl, Katharina N; Kastner, Sabine; Peelen, Marius V

    2014-01-01

    Visual cues from the face and the body provide information about another's identity, emotional state, and intentions. Previous neuroimaging studies that investigated neural responses to (bodiless) faces and (headless) bodies have reported overlapping face- and body-selective brain regions in right fusiform gyrus (FG). In daily life, however, faces and bodies are typically perceived together and are effortlessly integrated into the percept of a whole person, raising the possibility that neural responses to whole persons are qualitatively different than responses to isolated faces and bodies. The present study used fMRI to examine how FG activity in response to a whole person relates to activity in response to the same face and body but presented in isolation. Using multivoxel pattern analysis, we modeled person-evoked response patterns in right FG through a linear combination of face- and body-evoked response patterns. We found that these synthetic patterns were able to accurately approximate the response patterns to whole persons, with face and body patterns each adding unique information to the response patterns evoked by whole person stimuli. These results suggest that whole person responses in FG primarily arise from the coactivation of independent face- and body-selective neural populations.

  16. Cervical intraspinal microstimulation evokes robust forelimb movements before and after injury

    Science.gov (United States)

    Sunshine, Michael D.; Cho, Frances S.; Lockwood, Danielle R.; Fechko, Amber S.; Kasten, Michael R.; Moritz, Chet T.

    2013-06-01

    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.

  17. A Parallel World for the World Bank: A Case Study of Urgent: Evoke, An Educational Alternate Reality Game

    Directory of Open Access Journals (Sweden)

    David I. Waddington

    2013-01-01

    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.

  18. The Electrically Evoked Compound Action Potential: From Laboratory to Clinic.

    Science.gov (United States)

    He, Shuman; Teagle, Holly F B; Buchman, Craig A

    2017-01-01

    The electrically evoked compound action potential (eCAP) represents the synchronous firing of a population of electrically stimulated auditory nerve fibers. It can be directly recorded on a surgically exposed nerve trunk in animals or from an intra-cochlear electrode of a cochlear implant. In the past two decades, the eCAP has been widely recorded in both animals and clinical patient populations using different testing paradigms. This paper provides an overview of recording methodologies and response characteristics of the eCAP, as well as its potential applications in research and clinical situations. Relevant studies are reviewed and implications for clinicians are discussed.

  19. Estimation of evoked potentials using total least squares prony technique.

    Science.gov (United States)

    Akkin, T; Saliu, S

    1998-09-01

    The authors investigate the applicability of Prony modelling to the estimation of evoked potentials. Four types of total least squares (TLS) model are considered and their optimal parameters are defined based on ten visual averaged EPs. Simulations with various signal and noise characteristics show that the TLS-Prony estimation is superior to averaging for two of the models, namely the unconstrained and the stable models. Application of the TLS-Prony estimator as a post-processor to moderate averaging allows a reduction in the number of responses averaged, or equivalently of recording time, by a factor of two.

  20. Sensory gating of auditory evoked potentials in rats: Effects of repetitive stimulation and the interstimulus interval

    NARCIS (Netherlands)

    Bruin, N.M.W.J. de; Ellenbroek, B.A.; Schaijk, W.J. van; Cools, A.R.; Coenen, A.M.L.; Luijtelaar, E.L.J.M. van

    2001-01-01

    In the P50 gating or conditioning-testing (C-T) paradigm, the P50 response, a small positive midlatency (~50 ms after stimulus onset) component of the human auditory evoked potential (AEP), is reduced towards the second click (S2) as compared to the response to the first click (S1). This phenomenon

  1. Sensory gating of auditory evoked potentials in rats: effects of repetitive stimulation and the interstimulus interval.

    NARCIS (Netherlands)

    Bruin, N.M.W.J. de; Ellenbroek, B.A.; Schaijk, W.J. van; Cools, A.R.; Coenen, A.M.L.; Luijtelaar, E.L.J.M. van

    2001-01-01

    In the P50 gating or conditioning-testing (C-T) paradigm, the P50 response, a small positive midlatency ( approximately 50 ms after stimulus onset) component of the human auditory evoked potential (AEP), is reduced towards the second click (S2) as compared to the response to the first click (S1).

  2. Multidimensional constrained test assembly

    NARCIS (Netherlands)

    Veldkamp, Bernard P.

    2002-01-01

    Two mathematical programming approaches are presented for the assembly of ability tests from item pools calibrated under a multidimensional item response theory model. Item selection is based on Fisher information matrix. Several criteria can be used to optimize this matrix. In this article, the

  3. Constrained multidimensional test assembly

    NARCIS (Netherlands)

    Veldkamp, Bernard P.

    2000-01-01

    Two mathematical programming approaches are presented for the assembly of ability test from item pools calibrated under a multidimensional item response theory model. Item selection is based on Fisher's Information matrix. Several criteria can be used to optimize this matrix. In this paper, the

  4. Evoked brain potentials and disability in brain-damaged patients.

    Science.gov (United States)

    Rappaport, M; Hall, K; Hopkins, K; Belleza, T; Berrol, S; Reynolds, G

    1977-08-01

    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.

  5. Lightweight cryptography for constrained devices

    DEFF Research Database (Denmark)

    Alippi, Cesare; Bogdanov, Andrey; Regazzoni, Francesco

    2014-01-01

    Lightweight cryptography is a rapidly evolving research field that responds to the request for security in resource constrained devices. This need arises from crucial pervasive IT applications, such as those based on RFID tags where cost and energy constraints drastically limit the solution...... complexity, with the consequence that traditional cryptography solutions become too costly to be implemented. In this paper, we survey design strategies and techniques suitable for implementing security primitives in constrained devices....

  6. Transient Evoked aotacoustic emissions otologically normal adults

    African Journals Online (AJOL)

    ABUTH

    Objective: To examine the effects of aging on the existence of transient evoked otoacoustic emissions in normal adult. Material and methods 40 ... wax or any middle ear pathology which might affect the recording at TEOAEs. After that, ... related to decreased hearing sensitivity and are independent of aging, Previous studies.

  7. Neural correlates of evoked phantom limb sensations.

    Science.gov (United States)

    Andoh, J; Diers, M; Milde, C; Frobel, C; Kleinböhl, D; Flor, H

    2017-05-01

    Previous work showed the existence of changes in the topographic organization within the somatosensory cortex (SI) in amputees with phantom limb pain, however, the link between nonpainful phantom sensations such as cramping or tingling or the percept of the limb and cortical changes is less clear. We used functional magnetic resonance imaging (fMRI) in a highly selective group of limb amputees who experienced inducible and reproducible nonpainful phantom sensations. A standardized procedure was used to locate body sites eliciting phantom sensations in each amputee. Selected body sites that could systematically evoke phantom sensations were stimulated using electrical pulses in order to induce phasic phantom sensations. Homologous body parts were also stimulated in a group of matched controls. Activations related to evoked phantom sensations were found bilaterally in SI and the intraparietal sulci (IPS), which significantly correlated with the intensity of evoked phantom sensations. In addition, we found differences in intra- and interhemispheric interaction between amputees and controls during evoked phantom sensations. We assume that phantom sensations might be associated with a functional decoupling between bilateral SI and IPS, possibly resulting from transcallosal reorganization mechanisms following amputation. Copyright © 2017. Published by Elsevier B.V.

  8. Combined δ11B, δ13C, and δ18O analyses of coccolithophore calcite constrains the response of coccolith vesicle carbonate chemistry to CO2-induced ocean acidification

    Science.gov (United States)

    Liu, Yi-Wei; Tripati, Robert; Aciego, Sarah; Gilmore, Rosaleen; Ries, Justin

    2016-04-01

    Coccolithophorid algae play a central role in the biological carbon pump, oceanic carbon sequestration, and in marine food webs. It is therefore important to understand the potential impacts of CO2-induced ocean acidification on these organisms. Differences in the regulation of carbonate chemistry, pH, and carbon sources of the intracellular compartments where coccolith formation occurs may underlie the diverse calcification and growth responses to acidified seawater observed in prior experiments. Here we measured stable isotopes of boron (δ11B), carbon (δ13C) and oxygen (δ18O) within coccolith calcite, and δ13C of algal tissue to constrain carbonate system parameters in two strains of Pleurochrysis carterae (P. carterae). The two strains were cultured under variable pCO2, with water temperature, salinity, dissolved inorganic carbon (DIC), and alkalinity monitored. Notably, PIC, POC, and PIC/POC ratio did not vary across treatments, indicating that P. carterae is able to calcify and photosynthesize at relatively constant rates irrespective of pCO2 treatment. The δ11B data indicate that mean pH at the site of coccolith formation did not vary significantly in response to elevated CO2. These results suggest that P. carterae regulates calcifying vesicle pH, even amidst changes in external seawater pH. Furthermore, δ13C and δ18O data suggest that P. carterae may utilize carbon from a single internal DIC pool for both calcification and photosynthesis, and that a greater proportion of dissolved CO2 relative to HCO3- enters the internal DIC pool under acidified conditions. These results suggest that P. carterae is able to calcifyand photosynthesize at relatively constant rates across pCO2 treatments by maintaining pH homeostasis at their site of calcification and utilizing a greater proportion of aqueous CO2.

  9. Isoflurane reduces the carbachol-evoked Ca2+ influx in neuronal cells.

    Science.gov (United States)

    Corrales, Alexandra; Xu, Fang; Garavito-Aguilar, Zayra V; Blanck, Thomas J J; Recio-Pinto, Esperanza

    2004-10-01

    The authors previously reported that the isoflurane-caused reduction of the carbachol-evoked cytoplasmic Ca transient increase ([Ca]cyt) was eliminated by K or caffeine-pretreatment. In this study the authors investigated whether the isoflurane-sensitive component of the carbachol-evoked [Ca]cyt transient involved Ca influx through the plasma membrane. Perfused attached human neuroblastoma SH-SY5Y cells were exposed to carbachol (1 mm, 2 min) in the absence and presence of isoflurane (1 mm) and in the absence and presence of extracellular Ca (1.5 mm). The authors studied the effect of the nonspecific cationic channel blocker La (100 microm), of the L-type Ca channel blocker nitrendipine (10 microm), and of the N-type Ca channel blocker omega-conotoxin GVIA (0.1 microm) on isoflurane modulation of the carbachol-evoked [Ca]cyt transient. [Ca]cyt was detected with fura-2 and experiments were carried out at 37 degrees C. Isoflurane reduced the peak and area of the carbachol-evoked [Ca]cyt transient in the presence but not in the absence of extracellular Ca. La had a similar effect as the removal of extracellular Ca. Omega-conotoxin GVIA and nitrendipine did not affect the isoflurane sensitivity of the carbachol response although nitrendipine reduced the magnitude of the carbachol response. The current data are consistent with previous observations in that the carbachol-evoked [Ca]cyt transient involves both Ca release from intracellular Ca stores and Ca entry through the plasma membrane. It was found that isoflurane attenuates the carbachol-evoked Ca entry. The isoflurane sensitive Ca entry involves a cationic channel different from the L- or N- type voltage-dependent Ca channels. These results indicate that isoflurane attenuates the carbachol-evoked [Ca]cyt transient at a site at the plasma membrane that is distal to the muscarinic receptor.

  10. Visual acuity of the midland banded water snake estimated from evoked telencephalic potentials.

    Science.gov (United States)

    Baker, Robert A; Gawne, Timothy J; Loop, Michael S; Pullman, Sheena

    2007-08-01

    The visual acuity of seven midland banded water snakes was measured by recording evoked responses from telencephalon to temporally modulated square wave grating patterns. Using conventional electrophysiological techniques and signal averaging, high contrast square wave gratings of different spatial frequencies were presented. Acuity was estimated by extrapolating relative response amplitude/log(10) spatial frequency functions which yielded an average acuity of 4.25 cycles/degree. Refractive state was also estimated by recording evoked potentials to intermediate spatial frequencies with different lenses in front of the eye. Polynomial fits indicated that under the experimental conditions the snakes were around 6.4 diopters hyperopic suggesting a corrected acuity of 4.89 cycles/degree. Reduction of grating luminance resulted in a reduction in evoked potential acuity measurements. These results indicate that the spatial resolution of midland banded water snakes is the equal of cat; about 20/120 in human clinical terms.

  11. Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

    DEFF Research Database (Denmark)

    Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin

    2016-01-01

    attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization...

  12. Characteristics and clinical applications of ocular vestibular evoked myogenic potentials.

    Science.gov (United States)

    Kantner, C; Gürkov, R

    2012-12-01

    Recently, ocular vestibular evoked myogenic potentials (oVEMPs) have been described and added to the neuro-otologic test battery as a new measure for the vestibulo-ocular reflex. oVEMPs represent extraocular muscle activity in response to otolith stimulation e.g. by air-conducted sound or bone-conducted vibration. In response to vestibular stimulation, electromyographic activity of the extraocular muscles can be recorded by means of surface electrodes placed beneath the contralateral eye. oVEMPs are likely to reflect predominantly utricular function, while the widely established cervical vestibular evoked myogenic potentials (cVEMPs) assess saccular function. Thus, measuring oVEMPs and cVEMPs in addition to caloric and head impulse testing provides further evaluation of the vestibular system and enables quick and cost-effective assessment of otolith function. This review summarizes the neurophysiological properties of oVEMPs, gives recommendations for recording conditions and discusses oVEMP alterations in various disorders of the vestibular system. With increasing insight into oVEMP characteristics in vestibular disorders, e.g. Menière's disease and superior semicircular canal dehiscence syndrome, oVEMPs are becoming a promising new diagnostic tool for evaluating utricular function. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Synaptically evoked glutamate transporter currents in Spinal Dorsal Horn Astrocytes

    Directory of Open Access Journals (Sweden)

    Dougherty Patrick M

    2009-07-01

    Full Text Available Abstract Background Removing and sequestering synaptically released glutamate from the extracellular space is carried out by specific plasma membrane transporters that are primarily located in astrocytes. Glial glutamate transporter function can be monitored by recording the currents that are produced by co-transportation of Na+ ions with the uptake of glutamate. The goal of this study was to characterize glutamate transporter function in astrocytes of the spinal cord dorsal horn in real time by recording synaptically evoked glutamate transporter currents. Results Whole-cell patch clamp recordings were obtained from astrocytes in the spinal substantia gelatinosa (SG area in spinal slices of young adult rats. Glutamate transporter currents were evoked in these cells by electrical stimulation at the spinal dorsal root entry zone in the presence of bicuculline, strychnine, DNQX and D-AP5. Transporter currents were abolished when synaptic transmission was blocked by TTX or Cd2+. Pharmacological studies identified two subtypes of glutamate transporters in spinal astrocytes, GLAST and GLT-1. Glutamate transporter currents were graded with stimulus intensity, reaching peak responses at 4 to 5 times activation threshold, but were reduced following low-frequency (0.1 – 1 Hz repetitive stimulation. Conclusion These results suggest that glutamate transporters of spinal astrocytes could be activated by synaptic activation, and recording glutamate transporter currents may provide a means of examining the real time physiological responses of glial cells in spinal sensory processing, sensitization, hyperalgesia and chronic pain.

  14. Generalized bracket formulation of constrained dynamics in phase space.

    Science.gov (United States)

    Sergi, Alessandro

    2004-02-01

    A generalized bracket formalism is used to define the phase space flow of constrained systems. The generalized bracket naturally subsumes the approach to constrained dynamics given by Dirac some time ago. The dynamical invariant measure and the linear response of systems subjected to holonomic constraints are explicitly derived. In light of previous results, it is shown that generalized brackets provide a simple and unified view of the statistical mechanics of non-Hamiltonian phase space flows with a conserved energy.

  15. Thought-evoking approaches in engineering problems

    CERN Document Server

    2014-01-01

    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’,...

  16. 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

    2009-10-01

    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

  17. Complexin Mutants Reveal Partial Segregation between Recycling Pathways That Drive Evoked and Spontaneous Neurotransmission

    Science.gov (United States)

    Sabeva, Nadezhda; Cho, Richard W.; Vasin, Alexander; Gonzalez, Agustin; Littleton, J. Troy

    2017-01-01

    Synaptic vesicles fuse at morphological specializations in the presynaptic terminal termed active zones (AZs). Vesicle fusion can occur spontaneously or in response to an action potential. Following fusion, vesicles are retrieved and recycled within nerve terminals. It is still unclear whether vesicles that fuse spontaneously or following evoked release share similar recycling mechanisms. Genetic deletion of the SNARE-binding protein complexin dramatically increases spontaneous fusion, with the protein serving as the synaptic vesicle fusion clamp at Drosophila synapses. We examined synaptic vesicle recycling pathways at complexin null neuromuscular junctions, where spontaneous release is dramatically enhanced. We combined loading of the lipophilic dye FM1–43 with photoconversion, electron microscopy, and electrophysiology to monitor evoked and spontaneous recycling vesicle pools. We found that the total number of recycling vesicles was equal to those retrieved through spontaneous and evoked pools, suggesting that retrieval following fusion is partially segregated for spontaneous and evoked release. In addition, the kinetics of FM1–43 destaining and synaptic depression measured in the presence of the vesicle-refilling blocker bafilomycin indicated that spontaneous and evoked recycling pools partially intermix during the release process. Finally, FM1–43 photoconversion combined with electron microscopy analysis indicated that spontaneous recycling preferentially involves synaptic vesicles in the vicinity of AZs, whereas vesicles recycled following evoked release involve a larger intraterminal pool. Together, these results suggest that spontaneous and evoked vesicles use separable recycling pathways and then partially intermix during subsequent rounds of fusion. SIGNIFICANCE STATEMENT Neurotransmitter release involves fusion of synaptic vesicles with the plasma membrane in response to an action potential, or spontaneously in the absence of stimulation. Upon

  18. Video outside versus video inside the web: do media setting and image size have an impact on the emotion-evoking potential of video?

    NARCIS (Netherlands)

    Verleur, R.; Verhagen, Pleunes Willem; Crawford, Margaret; Simonson, Michael; Lamboy, Carmen

    2001-01-01

    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

  19. Selecting the smoothing parameter for estimation of slowly changing evoked potential signals.

    Science.gov (United States)

    Raz, J; Turetsky, B; Fein, G

    1989-09-01

    Brain evoked potential (EP) data consist of a true response ("signal") and random background activity ("noise"), which are observed over repeated stimulus presentations ("trials"). A signal that changes slowly from trial to trial can be estimated by smoothing across trials and over time within trials. We present a method for selecting the smoothing parameter by minimizing an estimate of the mean average squared error (MASE). We evaluate the performance of this method using simulated EP data, and apply the method to an example set of real flash evoked potentials.

  20. Thoracic and thoracoabdominal aortic aneurysm repair : use of evoked potential monitoring in 118 patients

    NARCIS (Netherlands)

    van Dongen, E.P.; Schepens, M A; Morshuis, W J; ter Beek, H T; Aarts, L P; de Boer, A; Boezeman, E H

    2001-01-01

    PURPOSE: Paraplegia is the most dreaded and severe complication of surgery on the descending thoracic aorta (TAA) and thoracoabdominal aorta (TAAA). The functional integrity of the spinal cord can be monitored by means of intraoperative recording of myogenic-evoked responses after transcranial

  1. Choline evokes fluid secretion by perfused rat mandibular gland without desensitization

    DEFF Research Database (Denmark)

    Murakami, M; Novak, I; Young, J A

    1986-01-01

    of muscarinic receptors, but it is unclear why choline does not evoke tachyphylaxis. The response to choline allows us to exclude a number of the possible causes of tachyphylaxis that have previously been considered, so that an excessive buildup of cytosolic free Ca now remains as the most likely cause...

  2. 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

    2015-01-01

    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

  3. 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.

    2015-01-01

    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

  4. Effects of single cycle binaural beat duration on auditory evoked potentials.

    Science.gov (United States)

    Mihajloski, Todor; Bohorquez, Jorge; Özdamar, Özcan

    2014-01-01

    Binaural beat (BB) illusions are experienced as continuous central pulsations when two sounds with slightly different frequencies are delivered to each ear. It has been shown that steady-state auditory evoked potentials (AEPs) to BBs can be captured and investigated. The authors recently developed a new method of evoking transient AEPs to binaural beats using frequency modulated stimuli. This methodology was able to create single BBs in predetermined intervals with varying carrier frequencies. This study examines the effects of the BB duration and the frequency modulating component of the stimulus on the binaural beats and their evoked potentials. Normal hearing subjects were tested with a set of four durations (25, 50, 100, and 200 ms) with two stimulation configurations, binaural dichotic (binaural beats) and diotic (frequency modulation). The results obtained from the study showed that out of the given durations, the 100 ms beat, was capable of evoking the largest amplitude responses. The frequency modulation effect showed a decrease in peak amplitudes with increasing beat duration until their complete disappearance at 200 ms. Even though, at 200 ms, the frequency modulation effects were not present, the binaural beats were still perceived and captured as evoked potentials.

  5. Magnetic fields evoked by speech sounds in preschool children.

    Science.gov (United States)

    Pihko, Elina; Kujala, Teija; Mickos, Annika; Antell, Henrik; Alku, Paavo; Byring, Roger; Korkman, Marit

    2005-01-01

    Our objective was to study how well the auditory evoked magnetic fields (EF) reflect the behavioral discrimination of speech sounds in preschool children, and if they reveal the same information as simultaneously recorded evoked potentials (EP). EFs and EPs were recorded in 11 preschool children (mean age 6 years 9 months) using an oddball paradigm with two sets of speech stimuli consisting both of one standard and two deviants. After the brain activity recording, children were tested on behavioural discrimination of the same stimuli presented in pairs. There was a mismatch negativity (MMN) calculated from difference curves and its magnetic counterpart MMNm measured from the original responses only to those deviants, which were behaviourally easiest to discriminate from the standards. In addition, EF revealed significant differences between the locations of the activation depending on the hemisphere and stimulus properties. EF, in addition to reflecting the sound-discrimination accuracy in a similar manner as EP, also reflected the spatial differences in activation of the temporal lobes. These results suggest that both EPs and EFs are feasible for investigating the neural basis of sound discrimination in young children. The recording of EFs with its high spatial resolution reveals information on the location of the activated neural sources.

  6. Somatosensory evoked potentials in children with severe head trauma.

    Science.gov (United States)

    Schalamon, Johannes; Singer, Georg; Kurschel, Senta; Höllwarth, Michael E

    2005-07-01

    We evaluated the predictive value of somatosensory evoked potentials (SEP) in a series of children with severe traumatic brain injury (TBI). The prospective clinical investigation was performed in a Level I paediatric trauma centre. We included 26 consecutive comatose paediatric patients aged from 1 month to 17 years (median age 11 years) following severe TBI (initial Glasgow Coma Score (GCS) 8 or below). Besides SEP recordings, the intracranial pressure and the results of an initial cranial CT scan were filed. The Glasgow Outcome Scale (GOS) was used to assess outcome at discharge. Thirteen children had normal SEP measurements, three patients had abnormal SEP recordings and a cortical response was bilaterally absent in ten children. Out of 26 children, 10 died whereas two remained in a persistent vegetative state. Only one child suffered from significant neurological deficits (GOS 3) at discharge. Seven patients survived with a GOS of 4 and six children survived without neurological impairment (GOS 5). Normal SEP indicated a favourable outcome in most children but did not rule out the occurrence of death, while absence of SEP was related to unfavourable outcome in all cases. Measurement of somatosensory evoked potentials provides valuable data for determining the prognosis at early coma stages. Our data show that an unfavourable outcome can be predicted with higher precision than a favourable outcome.

  7. Neurogenic vestibular evoked potentials using a tone pip auditory stimulus.

    Science.gov (United States)

    Papathanasiou, E S; Zamba-Papanicolaou, E; Pantziaris, M; Kleopas, K; Kyriakides, T; Papacostas, S; Pattichis, C; Iliopoulos, I; Piperidou, C

    2004-01-01

    To obtain neurogenic vestibular evoked potentials (NVESTEPs) with surface scalp recording using a tone pip auditory stimulus. Fourteen neurologically normal volunteers (Age range 26-45 years, 10 females and 4 males), and two patients with sensorineural hearing loss and possible multiple sclerosis respectively, were examined. Two channel recordings were obtained, the first channel being P3 referred to Fpz, and the second channel being P4 referred to Fpz. A 1 kHz tone pip stimulus with two cycles was delivered via headphones monoaurally with contralateral masking noise. A consistent negative wave with a mean absolute latency of 4.72 msec was obtained, which we have named N5. 25% of the ears tested had better responses at the ipsilateral parietal electrode. In the patient with bilateral sensorineural hearing loss, NVESTEPs was present, suggesting that the NVESTEP is not a cochlear response. In the patient with possible multiple sclerosis, an abnormal NVESTEP response and a normal BAEP response were found. Use of a tone-pip rather than a click auditory stimulus allows a lower click intensity to be used in the production of NVESTEP responses, leads to a shorter testing time, and is therefore more comfortable for the patient. This study adds to our impression that the NVESTEP may be a physiological response that can be used to assess the vestibular system and is different from the BAEP response. Further testing in patients with symptoms of dizziness and with disorders specific for the vestibular nerve is required.

  8. On the use of information theory for the analysis of synchronous nociceptive withdrawal reflexes and somatosensory evoked potentials elicited by graded electrical stimulation.

    Science.gov (United States)

    Arguissain, Federico G; Biurrun Manresa, José A; Mørch, Carsten D; Andersen, Ole K

    2015-01-30

    To date, few studies have combined the simultaneous acquisition of nociceptive withdrawal reflexes (NWR) and somatosensory evoked potentials (SEPs). In fact, it is unknown whether the combination of these two signals acquired simultaneously could provide additional information on somatosensory processing at spinal and supraspinal level compared to individual NWR and SEP signals. By using the concept of mutual information (MI), it is possible to quantify the relation between electrical stimuli and simultaneous elicited electrophysiological responses in humans based on the estimated stimulus-response signal probability distributions. All selected features from NWR and SEPs were informative in regard to the stimulus when considered individually. Specifically, the information carried by NWR features was significantly higher than the information contained in the SEP features (pinformation carried by the combination of features showed an overall redundancy compared to the sum of the individual contributions. Comparison with existing methods MI can be used to quantify the information that single-trial NWR and SEP features convey, as well as the information carried jointly by NWR and SEPs. This is a model-free approach that considers linear and non-linear correlations at any order and is not constrained by parametric assumptions. The current study introduces a novel approach that allows the quantification of the individual and joint information content of single-trial NWR and SEP features. This methodology could be used to decode and interpret spinal and supraspinal interaction in studies modulating the responsiveness of the nociceptive system. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Sex differences in the association between stressor-evoked interleukin-6 reactivity and C-reactive protein.

    Science.gov (United States)

    Lockwood, Kimberly G; Marsland, Anna L; Cohen, Sheldon; Gianaros, Peter J

    2016-11-01

    Individuals differ consistently in the magnitude of their inflammatory responses to acute stressors, with females often showing larger responses than males. While the clinical significance of these individual differences remains unclear, it may be that greater inflammatory responses relate to increased systemic inflammation and thereby risk for chronic inflammatory disease. Here, we examined whether acute stressor-evoked interleukin (IL)-6 responses associate with resting levels of C-reactive protein (CRP), a marker of systemic inflammation, and whether this association differs by sex. Subjects were 57 healthy midlife adults (30-51years; 33% female; 68% white). Blood was drawn before and 30-min after two mental stress tasks: a multisource interference task and a Stroop color word task. Hierarchical regressions controlling for age, sex, race, and BMI tested whether stressor-evoked IL-6 responses were associated with resting CRP and whether this association differed by sex. Results indicated that sex and stressor-evoked IL-6 responses interacted to predict CRP (ΔR 2 =0.08, B=-1.33, β=-0.39, p=0.02). In males, larger stressor-evoked IL-6 responses associated with higher CRP, whereas in females, stressor-evoked IL-6 responses showed a non-significant negative association with CRP. These findings indicate that inflammatory responses to acute stressors associate with resting levels of CRP; however, this association differs by sex. Previous literature suggests that there are sex differences in stressor-evoked IL-6 responses, but this is the first study to show sex differences in the relationship between acute inflammatory responses and systemic inflammation. The contribution of these sex differences to inflammatory disease risk warrants further investigation. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Trends in PDE constrained optimization

    CERN Document Server

    Benner, Peter; Engell, Sebastian; Griewank, Andreas; Harbrecht, Helmut; Hinze, Michael; Rannacher, Rolf; Ulbrich, Stefan

    2014-01-01

    Optimization problems subject to constraints governed by partial differential equations (PDEs) are among the most challenging problems in the context of industrial, economical and medical applications. Almost the entire range of problems in this field of research was studied and further explored as part of the Deutsche Forschungsgemeinschaft (DFG) priority program 1253 on “Optimization with Partial Differential Equations” from 2006 to 2013. The investigations were motivated by the fascinating potential applications and challenging mathematical problems that arise in the field of PDE constrained optimization. New analytic and algorithmic paradigms have been developed, implemented and validated in the context of real-world applications. In this special volume, contributions from more than fifteen German universities combine the results of this interdisciplinary program with a focus on applied mathematics.   The book is divided into five sections on “Constrained Optimization, Identification and Control”...

  11. Constraining spacetime torsion with LAGEOS

    Science.gov (United States)

    March, Riccardo; Bellettini, Giovanni; Tauraso, Roberto; Dell'Agnello, Simone

    2011-11-01

    We compute the corrections to the orbital Lense-Thirring effect (or frame-dragging) in the presence of spacetime torsion. We analyze the motion of a test body in the gravitational field of a rotating axisymmetric massive body, using the parametrized framework of Mao, Tegmark, Guth and Cabi. In the cases of autoparallel and extremal trajectories, we derive the specific approximate expression of the corresponding system of ordinary differential equations, which are then solved with methods of Celestial Mechanics. We calculate the secular variations of the longitudes of the node and of the pericenter. We also show how the LAser GEOdynamics Satellites (LAGEOS) can be used to constrain torsion parameters. We report the experimental constraints obtained using both the nodes and perigee measurements of the orbital Lense-Thirring effect. This makes LAGEOS and Gravity Probe B complementary frame-dragging and torsion experiments, since they constrain three different combinations of torsion parameters.

  12. Constrained Multiobjective Biogeography Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Hongwei Mo

    2014-01-01

    Full Text Available Multiobjective optimization involves minimizing or maximizing multiple objective functions subject to a set of constraints. In this study, a novel constrained multiobjective biogeography optimization algorithm (CMBOA is proposed. It is the first biogeography optimization algorithm for constrained multiobjective optimization. In CMBOA, a disturbance migration operator is designed to generate diverse feasible individuals in order to promote the diversity of individuals on Pareto front. Infeasible individuals nearby feasible region are evolved to feasibility by recombining with their nearest nondominated feasible individuals. The convergence of CMBOA is proved by using probability theory. The performance of CMBOA is evaluated on a set of 6 benchmark problems and experimental results show that the CMBOA performs better than or similar to the classical NSGA-II and IS-MOEA.

  13. Similar itch and nociceptive sensations evoked by punctate cutaneous application of capsaicin, histamine and cowhage

    Science.gov (United States)

    Sikand, Parul; Shimada, Steven G.; Green, Barry G.; LaMotte, Robert H.

    2009-01-01

    Itch evoked by cowhage or histamine is reduced or blocked by capsaicin desensitization, suggesting that pruriceptive neurons are capsaicin-sensitive. Topical capsaicin can evoke both nociceptive sensations and itch, whereas intradermal injection of capsaicin evokes only burning pain. To dissociate the pruritic and nociceptive sensory effects caused by the chemical activation of sensory neurons, chemicals were applied in a punctiform manner to the skin of the forearm using individual, heat-inactivated cowhage spicules treated with various concentrations of capsaicin (1–200 mg/ml) or histamine (0.01–100 mg/ml). Perceived intensities of itch, pricking/stinging and burning were obtained every 30s using the general version of the Labeled Magnitude Scale and compared with ratings evoked by individual native cowhage spicules. Similar to cowhage, capsaicin and histamine spicules reliably evoked sensations of itch in a dose-dependent manner that were most often accompanied by pricking/stinging and to a lesser extent burning. Spicules containing 200 mg/ml capsaicin or 10 mg/ml histamine yielded peak magnitudes and durations of sensations comparable to those elicited by cowhage. Each type of spicule also produced comparable areas of dysesthesias (enhanced mechanically evoked itch or pain) and/or skin reactions (wheal and/or flare) in surrounding skin, though inconsistently. The incidence of flare was greater in response to histamine than to capsaicin or cowhage. These results suggest the possibility that capsaicin, histamine and cowhage activate common peripheral or central neural mechanisms that mediate pruritic sensations and associated dysesthesias. PMID:19423224

  14. Motor behaviors in the sheep evoked by electrical stimulation of the subthalamic nucleus.

    Science.gov (United States)

    Lentz, Linnea; Zhao, Yan; Kelly, Matthew T; Schindeldecker, William; Goetz, Steven; Nelson, Dwight E; Raike, Robert S

    2015-11-01

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is used to treat movement disorders, including advanced Parkinson's disease (PD). The pathogenesis of PD and the therapeutic mechanisms of DBS are not well understood. Large animal models are essential for investigating the mechanisms of PD and DBS. The purpose of this study was to develop a novel sheep model of STN DBS and quantify the stimulation-evoked motor behaviors. To do so, a large sample of animals was chronically-implanted with commercial DBS systems. Neuroimaging and histology revealed that the DBS leads were implanted accurately relative to the neurosurgical plan and also precisely relative to the STN. It was also possible to repeatedly conduct controlled evaluations of stimulation-evoked motor behavior in the awake-state. The evoked motor responses depended on the neuroanatomical location of the electrode contact selected for stimulation, as contacts proximal to the STN evoked movements at significantly lower voltages. Tissue stimulation modeling demonstrated that selecting any of the contacts stimulated the STN, whereas selecting the relatively distal contacts often also stimulated thalamus but only the distal-most contact stimulated internal capsule. The types of evoked motor behaviors were specific to the stimulation frequency, as low but not high frequencies consistently evoked movements resembling human tremor or dyskinesia. Electromyography confirmed that the muscle activity underlying the tremor-like movements in the sheep was consistent with human tremor. Overall, this work establishes that the sheep is a viable a large-animal platform for controlled testing of STN DBS with objective motor outcomes. Moreover, the results support the hypothesis that exaggerated low-frequency activity within individual nodes of the motor network can drive symptoms of human movement disorders, including tremor and dyskinesia. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Evoked potentials in pediatric cerebral malaria

    Directory of Open Access Journals (Sweden)

    Minal Bhanushali

    2011-08-01

    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.

  16. [Personality dimensions and cerebral evoked potential].

    Science.gov (United States)

    Camposano, S; Alvarez, C; Lolas, F

    1994-12-01

    Eysenck's personality theory postulates 3 orthogonal dimensions of personality: extraversion (E), neuroticism (N) and psychoticism (P), predicting conductual and physiological predispositions to suffer mental illness. Biological bases of Eysenck's personality traits have been documented electrophysiologically. Psychoticism, the latest described dimension, is controverted, since there is some evidence of common factors with the other two. In order to assess the relation between Eysenck's dimensions and sensorial reactivity and information encoding processes we studied 20 healthy young subjects (mean age 28.5 years) with flash visual cortical evoked potentials (VEP, 3 intensities, peak to peak amplitude of III, IV-V-VI, VII components), and auditory cognitive evoked potentials (odd ball paradigm, P300 latency). There was a positive correlation between N and P dimensions (Spearman, r = 0.52), between N and VEP amplitude at high intensity (r = 0.58) and a negative correlation between E and P300 latency (r = 0.58). In short we found that P is not an independent dimension, but is related to sensorial reactivity. E dimension was related to encoding processes supporting Eysenck's observations about memory and learning differences.

  17. Long Latency Auditory Evoked Potentials during Meditation.

    Science.gov (United States)

    Telles, Shirley; Deepeshwar, Singh; Naveen, Kalkuni Visweswaraiah; Pailoor, Subramanya

    2015-10-01

    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. © EEG and Clinical Neuroscience Society (ECNS) 2014.

  18. Role of motor evoked potentials in diagnosis of cauda equina and lumbosacral cord lesions.

    Science.gov (United States)

    Di Lazzaro, V; Pilato, F; Oliviero, A; Saturno, E; Dileone, M; Tonali, P A

    2004-12-28

    To determine the diagnostic value of motor evoked potentials (MEPs) in the diagnosis of lumbosacral cord disorders. MEPs in 37 patients with sensory and motor deficits in the lower limbs were studied. MRI demonstrated spinal cord involvement in 10 patients and cauda equina lesions in 27 patients. A double determination of central motor conduction time (CMCT), calculated as the difference between the latencies of responses evoked by cortical and paravertebral magnetic stimulation and as the difference between the latency of cortical MEP and the total peripheral conduction time calculated from the F-wave latency, enabled discrimination between a delay along the proximal root and a delay along the corticospinal tract. An abnormality of the CMCT calculated with both techniques is indicative of central motor pathway damage, whereas an abnormality of the CMCT calculated from the latency of responses evoked by paravertebral magnetic stimulation associated with a normal CMCT calculated from the F-wave latency suggests a cauda equina lesion. Neurophysiologic findings strongly correlated with the lesion site documented by MRI (cauda equina or lumbosacral cord). All patients with MR evidence of cord involvement had an abnormality of CMCT calculated with both methods, suggesting a lesion of central motor pathways. Clinical examination often failed to document a spinal cord lesion, suggesting pure peripheral involvement in 5 of the 10 patients with MR evidence of cord lesion. Motor evoked potential recording is an accurate and easily applicable test for the diagnosis of lumbosacral spinal cord lesions.

  19. The additivity problem and constrained quantum channels

    Science.gov (United States)

    Holevo, A. S.

    2005-06-01

    We give formulations of the famous additivity conjecture for several important quantities characterizing quantum channel and prove their global equivalence to the additivity of the classical capacity of a channel under input constrains (like mean energy constrain).

  20. Comparação das respostas em neonatos normais para emissões otoacústicas evocadas nos equipamentos: ILO 292 e ILO Ecocheck Comparison of otoacustic evoked responses in normal neonates for ILO 292 and ILO Ecocheck

    Directory of Open Access Journals (Sweden)

    Fernanda C. Scamatti

    2003-08-01

    Full Text Available O equipamento portátil (ILO ECOCHECK, AUDX, entre outros é uma outra alternativa, além dos aparelhos tradicionais (ILO 292, Byologic, Celesta, etc. para a triagem auditiva em neonatos. OBJETIVO: Realizamos Emissões Otoacústicas Evocadas Transitórias com os dois equipamentos, em 88 recém-nascidos normais sem risco auditivo para observar as respostas obtidas, procurando determinar, assim, a concordância entre os dois equipamentos. FORMA DE ESTUDO: Clínico prospectivo. RESULTADO: Observamos que os neonatos que falharam no ILO 292 também falharam no ILO ECOCHECK, no entanto, nem todos que falharam no ILO ECOCHECK falharam no ILO 292. Também notamos que os que falharam no ILO ECOCHECK apresentaram ausência de resposta na primeira banda de freqüência analisável do ILO 292. CONCLUSÃO: Concluímos que o equipamento portátil mostrou-se mais rigoroso na caracterização do exame normal do que o critério de normalidade utilizado na avaliação do exame convencional.The portable equipment (ILO ECOCHECK - AUDX, among others is another alternative besides the traditional devices (ILO 292 - BYOLOGIC, CELESTA, etc. for the auditive selection in newborn children. AIM: We have realized transiently otoacoustics emissions with both devices, in 88 normal newborn children without risk of auditive danger to observe the responses gotten with both, determining, this way, the agreement between both devices. STUDY DESIGN: Clinical prospective. RESULTS: We have noticed that the newborn children who failed in ILO 292 also failed in ILO ECOCHECK; however, not all of them who failed in ILO ECOCHECK failed in ILO 292. We have also noticed that the ones who had failed in ILO ECOCHEK had showed us no response in the first analyzable band of frequency of ILO 292. CONCLUSION: We have concluded that the portable equipament revealed itself more rigorous in the characterization of the normal exam than the criterion of normaity used in the evalution of the

  1. Fast detection of unexpected sound intensity decrements as revealed by human evoked potentials.

    Directory of Open Access Journals (Sweden)

    Heike Althen

    Full Text Available The detection of deviant sounds is a crucial function of the auditory system and is reflected by the automatically elicited mismatch negativity (MMN, an auditory evoked potential at 100 to 250 ms from stimulus onset. It has recently been shown that rarely occurring frequency and location deviants in an oddball paradigm trigger a more negative response than standard sounds at very early latencies in the middle latency response of the human auditory evoked potential. This fast and early ability of the auditory system is corroborated by the finding of neurons in the animal auditory cortex and subcortical structures, which restore their adapted responsiveness to standard sounds, when a rare change in a sound feature occurs. In this study, we investigated whether the detection of intensity deviants is also reflected at shorter latencies than those of the MMN. Auditory evoked potentials in response to click sounds were analyzed regarding the auditory brain stem response, the middle latency response (MLR and the MMN. Rare stimuli with a lower intensity level than standard stimuli elicited (in addition to an MMN a more negative potential in the MLR at the transition from the Na to the Pa component at circa 24 ms from stimulus onset. This finding, together with the studies about frequency and location changes, suggests that the early automatic detection of deviant sounds in an oddball paradigm is a general property of the auditory system.

  2. Auditory evoked fields elicited by spectral, temporal, and spectral-temporal changes in human cerebral cortex

    Directory of Open Access Journals (Sweden)

    Hidehiko eOkamoto

    2012-05-01

    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.

  3. Association between stimulus-evoked somatosensory inhibition and movement-related sensorimotor oscillation: A magnetoencephalographic study.

    Science.gov (United States)

    Hsiao, Fu-Jung; Chen, Wei-Ta; Lin, Yung-Yang

    2017-11-08

    The interaction between the somatosensory and motor cortices is understood; however, their functional relationship remains elusive. To elucidate the association between somatosensory and sensorimotor functions, this study investigated the correlation between somatosensory activities in response to paired-pulse stimulation and sensorimotor oscillations during self-paced finger movement in 18 healthy male subjects by using a magnetoencephalographic recording. The main finding was that stimulus-evoked somatosensory gating activities were significantly correlated with movement-related sensorimotor oscillatory responses. Specifically, the gating ratios of somatosensory N20m were related to the power changes of sensorimotor beta event-related desynchronization (ERD) (p=0.003) and event-related synchronization (ERS) (p=0.05). In conclusion, we confirmed that the inhibition of stimulus-evoked somatosensory responses is associated with the oscillatory characteristics of movement-related sensorimotor activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Constrained ballistics and geometrical optics

    CERN Document Server

    Epstein, Marcelo

    2014-01-01

    The problem of constant-speed ballistics is studied under the umbrella of non-linear non-holonomic constrained systems. The Newtonian approach is shown to be equivalent to the use of Chetaev's rule to incorporate the constraint within the initially unconstrained formulation. Although the resulting equations are not, in principle, obtained from a variational statement, it is shown that the trajectories coincide with those of geometrical optics in a medium with a suitably chosen refractive index, as prescribed by Fermat's principle of least time. This fact gives rise to an intriguing mechano-optical analogy. The trajectories are further studied and discussed.

  5. Constraining properties of disintegrating exoplanets

    Science.gov (United States)

    Veras, D.; Carter, P. J.; Leinhardt, Z. M.; Gänsicke, B. T.

    2017-09-01

    Evaporating and disintegrating planets provide unique insights into chemical makeup and physical constraints. The striking variability, depth (˜10 - 60%) and shape of the photometric transit curves due to the disintegrating minor planet orbiting white dwarf WD 1145+017 has galvanised the post-main- sequence exoplanetary science community. We have performed the first tidal disruption simulations of this planetary object, and have succeeded in constraining its mass, density, eccentricity and physical nature. We illustrate how our simulations can bound these properties, and be used in the future for other exoplanetary systems.

  6. Constraining walking and custodial technicolor

    DEFF Research Database (Denmark)

    Foadi, Roshan; Frandsen, Mads Toudal; Sannino, Francesco

    2008-01-01

    We show how to constrain the physical spectrum of walking technicolor models via precision measurements and modified Weinberg sum rules. We also study models possessing a custodial symmetry for the S parameter at the effective Lagrangian level-custodial technicolor-and argue that these models...... cannot emerge from walking-type dynamics. We suggest that it is possible to have a very light spin-one axial (vector) boson. However, in the walking dynamics the associated vector boson is heavy while it is degenerate with the axial in custodial technicolor Udgivelsesdato: 19 May...

  7. Auditory Evoked Potentials for the Evaluation of Hearing Sensitivity in Navy Dolphins. Assessment of Hearing Sensitivity in Adult Male Elephant Seals

    National Research Council Canada - National Science Library

    Houser, Dorian S

    2006-01-01

    A custom auditory evoked potential (AEP) system was used to assess the feasibility of rapidly testing the hearing of bottlenose dolphins by tracking the magnitude of the envelope following response (EFR...

  8. Auditory Evoked Potentials for the Evaluation of Hearing Sensitivity in Navy Dolphins. Modification P00002: Assessment of Hearing Sensitivity in Adult Male Elephant Seals

    National Research Council Canada - National Science Library

    Houser, Dorian S

    2006-01-01

    A custom auditory evoked potential (AEP) system was used to assess the feasibility of rapidly testing the hearing of bottlenose dolphins by tracking the magnitude of the envelope following response (EFR...

  9. Simultaneously estimating the task-related and stimulus-evoked components of hemodynamic imaging measurements.

    Science.gov (United States)

    Herman, Max Charles; Cardoso, Mariana M B; Lima, Bruss; Sirotin, Yevgeniy B; Das, Aniruddha

    2017-07-01

    Task-related hemodynamic responses contribute prominently to functional magnetic resonance imaging (fMRI) recordings. They reflect behaviorally important brain states, such as arousal and attention, and can dominate stimulus-evoked responses, yet they remain poorly understood. To help characterize these responses, we present a method for parametrically estimating both stimulus-evoked and task-related components of hemodynamic responses from subjects engaged in temporally predictable tasks. The stimulus-evoked component is modeled by convolving a hemodynamic response function (HRF) kernel with spiking. The task-related component is modeled by convolving a Fourier-series task-related function (TRF) kernel with task timing. We fit this model with simultaneous electrode recordings and intrinsic-signal optical imaging from the primary visual cortex of alert, task-engaged monkeys. With high [Formula: see text], the model returns HRFs that are consistent across experiments and recording sites for a given animal and TRFs that entrain to task timing independent of stimulation or local spiking. When the task schedule conflicts with that of stimulation, the TRF remains locked to the task emphasizing its behavioral origins. The current approach is strikingly more robust to fluctuations than earlier ones and gives consistently, if modestly, better fits. This approach could help parse the distinct components of fMRI recordings made in the context of a task.

  10. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy

    2011-12-01

    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.

  11. Ipsilesional Motor-Evoked Potential Absence in Pediatric Hemiparesis Impacts Tracking Accuracy of the Less Affected Hand

    OpenAIRE

    Cassidy, Jessica M.; Carey, James R.; Lu, Chiahao; Krach, Linda E.; Feyma, Tim; Durfee, William K.; GILLICK, BERNADETTE T

    2015-01-01

    This study analyzed the relationship between electrophysiological responses to transcranial magnetic stimulation (TMS), finger tracking accuracy, and volume of neural substrate in children with congenital hemiparesis. Nineteen participants demonstrating an ipsilesional motor-evoked potential (MEP) were compared with eleven participants showing an absent ipsilesional MEP response. Comparisons of finger tracking accuracy from the affected and less affected hands and ipsilesional/contralesional ...

  12. Facilitation and refractoriness of the electrically evoked compound action potential.

    Science.gov (United States)

    Hey, Matthias; Müller-Deile, Joachim; Hessel, Horst; Killian, Matthijs

    2017-11-01

    In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals from 13 to 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure. During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N1P1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state. ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. EFFECT OF SMOKING ON TRASIENTLY EVOKED OTOACOUSTIC EMISSION.

    Science.gov (United States)

    Gegenava, Kh; Japaridze, Sh; Sharashenidze, N; Jalabadze, G; Kevanishvili, Z

    2016-01-01

    Evoked otoacoustic emissions, EOAEs, are proved to be sounds aroused in response to external acoustic stimulus by the cochlear outer hair cells. Transiently evoked otoacoustic emissions, TEOAEs, are the most clinically utilized EOAEs. TEOAEs are detectable in 98% of people with normal hearing, regardless of age or sex, while two ears of any individual produce similar TEOAEs waveforms. The objective of the presented study was the comparison of TEOAE magnitudes in cigarette smokers and nonsmokers. The TEOAE occurrence and characteristics in individuals of both samples with audiometrically proved hearing losses and in those without were also specifically examined. 30 smokers and and 30 nonsmokers within the age range of 30-59 years were involved in the present study after informed concent. OAEs were performed to each subject by Madsen Capella's-OAE/middle ear analyzer-GN Otometrics, (Danmark). After OAE testing each subject was performed routine pure-tone audiometry and tympanometry. Obtained results were statistically treated by the student's t-distribution. According to our results 76.6% of smokers and 3.33% of nonsmokers had marked different level decrease in TEOAE amplitude. Audiographic measurments showed altered audiogram in 6.7% of smokers and in 3.33% of nonsmokers. Based on the above mentioned results we suppose that smoking has significant influence on hearing function, especially on cochlear apparatus; At the same time, TOEAE, as a sensitive method can be used for very early detection of hearing loss, even when there are neither any subjective complains nor some changies on audiogram.

  14. Glucagon-like peptide-2 modulates neurally evoked mucosal chloride secretion in guinea pig small intestine in vitro.

    Science.gov (United States)

    Baldassano, Sara; Liu, Sumei; Qu, Mei-Hu; Mulè, Flavia; Wood, Jackie D

    2009-10-01

    Glucagon-like peptide-2 (GLP-2) is an important neuroendocrine peptide in intestinal physiology. It influences digestion, absorption, epithelial growth, motility, and blood flow. We studied involvement of GLP-2 in intestinal mucosal secretory behavior. Submucosal-mucosal preparations from guinea pig ileum were mounted in Ussing chambers for measurement of short-circuit current (I(sc)) as a surrogate for chloride secretion. GLP-2 action on neuronal release of acetylcholine was determined with ELISA. Enteric neuronal expression of the GLP-2 receptor (GLP-2R) was studied with immunohistochemical methods. Application of GLP-2 (0.1-100 nM) to the serosal or mucosal side of the preparations evoked no change in baseline I(sc) and did not alter transepithelial ionic conductance. Transmural electrical field stimulation (EFS) evoked characteristic biphasic increases in I(sc), with an initially rapid rising phase followed by a sustained phase. Application of GLP-2 reduced the EFS-evoked biphasic responses in a concentration-dependent manner. The GLP-2R antagonist GLP-2-(3-33) significantly reversed suppression of the EFS-evoked responses by GLP-2. Tetrodotoxin, scopolamine, and hexamethonium, but not vasoactive intestinal peptide type 1 receptor (VPAC1) antagonist abolished or reduced to near zero the EFS-evoked responses. GLP-2 suppressed EFS-evoked acetylcholine release as measured by ELISA. Pretreatment with GLP-2-(3-33) offset this action of GLP-2. In the submucosal plexus, GLP-2R immunoreactivity (-IR) was expressed in choline acetyltransferase-IR neurons, somatostatin-IR neurons, neuropeptide Y-IR neurons, and vasoactive intestinal peptide-IR neurons. We conclude that submucosal neurons in the guinea pig ileum express GLP-2R. Activation of GLP-2R decreases neuronally evoked epithelial chloride secretion by suppressing acetylcholine release from secretomotor neurons.

  15. Resting Heart Rate and Auditory Evoked Potential

    Directory of Open Access Journals (Sweden)

    Simone Fiuza Regaçone

    2015-01-01

    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.

  16. Visual evoked potentials in rubber factory workers.

    Science.gov (United States)

    Tandon, O P; Kumar, V

    1997-01-01

    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.

  17. Music evokes vicarious emotions in listeners

    Science.gov (United States)

    Kawakami, Ai; Furukawa, Kiyoshi; Okanoya, Kazuo

    2014-01-01

    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. PMID:24910621

  18. A constrained model for MSMA

    Energy Technology Data Exchange (ETDEWEB)

    Capella, Antonio [Instituto de Matematicas, Universidad Nacional Autonoma de Mexico (Mexico); Mueller, Stefan [Hausdorff Center for Mathematics and Institute for Applied Mathematics, Universitaet Bonn (Germany); Otto, Felix [Max Planck Institute for Mathematics in the Sciences, Leipzig (Germany)

    2012-08-15

    A mathematical description of transformation processes in magnetic shape memory alloys (MSMA) under applied stresses and external magnetic fields needs a combination of micromagnetics and continuum elasticity theory. In this note, we discuss the so-called constrained theories, i.e., models where the state described by the pair (linear strain, magnetization) is at every point of the sample constrained to assume one of only finitely many values (that reflect the material symmetries). Furthermore, we focus on large body limits, i.e., models that are formulated in terms of (local) averages of a microstructured state, as the one proposed by DeSimone and James. We argue that the effect of an interfacial energy associated with the twin boundaries survives on the level of the large body limit in form of a (local) rigidity of twins. This leads to an alternative (i.e., with respect to reference 1) large body limit. The new model has the advantage of qualitatively explaining the occurrence of a microstructure with charged magnetic walls, as observed in SPP experiments in reference 2. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Repeated exercise stress impairs volitional but not magnetically evoked electromechanical delay of the knee flexors.

    Science.gov (United States)

    Minshull, Claire; Eston, Roger; Bailey, Andrea; Rees, Dai; Gleeson, Nigel

    2012-01-01

    The effects of serial episodes of fatigue and recovery on volitional and magnetically evoked neuromuscular performance of the knee flexors were assessed in 20 female soccer players during: (i) an intervention comprising 4 × 35 s maximal static exercise, and (ii) a control condition. Volitional peak force was impaired progressively (-16% vs. baseline: 235.3 ± 54.7 to 198.1 ± 38.5 N) by the fatiguing exercise and recovered to within -97% of baseline values following 6 min of rest. Evoked peak twitch force was diminished subsequent to the fourth episode of exercise (23.3%: 21.4 ± 13.8 vs. 16.4 ± 14.6 N) and remained impaired at this level throughout the recovery. Impairment of volitional electromechanical delay performance following the first episode of exercise (25.5%: 55.3 ± 11.9 vs. 69.5 ± 24.5 ms) contrasted with concurrent improvement (10.0%: 24.5 ± 4.7 vs. 22.1 ± 5.0 ms) in evoked electromechanical delay (P exercise provoked substantial impairments to volitional strength and volitional electromechanical delay that showed differential patterns of recovery. However, improved evoked electromechanical delay performance might identify a dormant capability for optimal muscle responses during acute stressful exercise and an improved capacity to maintain dynamic joint stability during critical episodes of loading.

  20. The pain-evoked P2 is not a P3a event-related potential.

    Science.gov (United States)

    Dowman, Robert

    2004-01-01

    The topographic pattern and latency of the P2 component of the somatosensory evoked potential elicited by painful electrical stimulation of the sural nerve was compared to the P3a event-related potential evoked by an infrequent task-irrelevant (deviant) innocuous sural nerve stimulus presented as part of the deviant-odd ball paradigm. Conditions typically used to record the sural nerve pain-evoked P2 (multiple stimulus levels, short fixed inter-stimulus intervals, and the subjects engaged in a pain rating task) did not elicit a P3a. The P3a was elicited when the painful stimuli were presented at a long and variable inter-stimulus interval. When present, the P3a occurred immediately following P2. These findings demonstrate that P2 is not a pain-evoked P3a. Rather, the response properties and latency of P2 present the possibility that it indexes a stimulus evaluation process where the sensory input is compared to an environmental template maintained by working memory.

  1. Feasibility and performance evaluation of generating and recording visual evoked potentials using ambulatory Bluetooth based system.

    Science.gov (United States)

    Ellingson, Roger M; Oken, Barry

    2010-01-01

    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.

  2. Language impairment is reflected in auditory evoked fields.

    Science.gov (United States)

    Pihko, Elina; Kujala, Teija; Mickos, Annika; Alku, Paavo; Byring, Roger; Korkman, Marit

    2008-05-01

    Specific language impairment (SLI) is diagnosed when a child has problems in producing or understanding language despite having a normal IQ and there being no other obvious explanation. There can be several associated problems, and no single underlying cause has yet been identified. Some theories propose problems in auditory processing, specifically in the discrimination of sound frequency or rapid temporal frequency changes. We compared automatic cortical speech-sound processing and discrimination between a group of children with SLI and control children with normal language development (mean age: 6.6 years; range: 5-7 years). We measured auditory evoked magnetic fields using two sets of CV syllables, one with a changing consonant /da/ba/ga/ and another one with a changing vowel /su/so/sy/ in an oddball paradigm. The P1m responses for onsets of repetitive stimuli were weaker in the SLI group whereas no significant group differences were found in the mismatch responses. The results indicate that the SLI group, having weaker responses to the onsets of sounds, might have slightly depressed sensory encoding.

  3. Relative efficacy of transcranial motor evoked potentials, mechanically-elicited electromyography, and evoked EMG to assess nerve root function during sustained retraction in a porcine model.

    Science.gov (United States)

    Lyon, Russ; Lieberman, Jeremy A; Feiner, John; Burch, Shane

    2009-07-15

    This is an animal experiment using transcranial motor evoked potentials (TcMEP), mechanically elicited electromyography (EMG), and evoked EMG during spinal nerve root retraction in a pig model. To compare the sensitivity of these 3 electrophysiological measures for a constant retraction force applied to an isolated lumbar nerve root for a specific duration of time. The incidence of nerve root injury during lumbar spine surgery ranges from 0.2% to 31%. Direct retraction of spinal nerve roots may cause these injuries, but the amount and duration of force that may safely be applied is not clear. Using an established porcine model, we examined the changes occurring to multimyotomal TcMEPs, mechanically elicited EMGs, and evoked EMGs during continuous retraction of a nerve root at a constant force applied over 10 minutes. TcMEP, mechanically elicited EMG, and evoked EMG responses were recorded from the tibialis anterior (TA) muscle in 10 experiments. The dominant root innervating the TA was determined with evoked EMG; preretraction TcMEP and nerve root stimulation threshold (NRT) was obtained. The dominant root was retracted at 2 Newton (N) for 10 minutes. TcMEP trials were elicited every minute during retraction. NRT was measured immediately after retraction. TcMEP and NRT were measured after 10 minutes of recovery. RESULTS.: During the 10 minutes of retraction at 2 N, the amplitude of the TA muscle progressively decreased in all trials in a highly significant curvilinear fashion. The mean TcMEP amplitude decreased 59% +/- 14% from baseline values. The mean NRT after 10 minutes of retraction at 2 N rose to 1.8 +/- 0.7 mA (P EMG activity was variable; tonic EMG was observed in only 2 nerve roots (20%). Three electrophysiologic methods were used intraoperatively to assess neural function during retraction of a single nerve root. Retraction produced consistent changes in TcMEPs and evoked EMG. These 2 methods show promise for assessing the limits on the force and duration

  4. Brainstem evoked response auditory in healthy term neonates with hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Isman Jafar

    2010-06-01

    bilirubin> 12 mg/dL will be subject for phototherapy. Objectives To determine the association between total bilirubin > 12 mg/dL and BERA abnonnalities in healthy tenn neonates, and the value of total bilirubin and free bilirubin that initiate abnonnal BERA. Methods This cross sectional study was carried out between March 31August 8, 2008, in healthy term neonates at roomingin ward, Department of Obstetric & Gy necology, Cipto Mangunkusumo Hospital (CMH. All eligible subjects were examined for Bf and BERA using standard methods.  Results The prevalence of abnormal BERA was 15.4%. There was no significant relation between hy perbilirubinemia (> 12 mg/ dL and abnonnal BERA in healthy tenn neonates. Lowest total bilirubin and Bf level related to abnonnal BERA were 12.4 mg/dL (mean 12.8 mg/dL and O.oSLg/dL (mean l.3Lg/dL, respectively. All BERA abnonnalities were unilateral. Conclusions There is no association between abnormal BERA and hyperbilirubinemia (total bilirubin> 12 mg/dL in jaundiced infants who undergo phototherapy.

  5. In Response to a Call: Evoking a Keynote

    OpenAIRE

    Neilson, Alison L.; São Marcos, Rita

    2016-01-01

    This is an escape from individualism, competition, and transmissive education practices which are the norms within higher education conferences of the neoliberal university. It is built from the script of a video abstract submitted to a call for keynote presenters for an international congress. Using tricksters and poetic presentations, we offer an open work inviting readers to have fun and make meaning from our provocative attempts.

  6. Responses evoked by a vestibular implant providing chronic stimulation

    OpenAIRE

    Thompson L.A.; Haburcakova C.; Gong W; Lee D.J.; Wall Iii C.; Merfeld D.M.; Lewis R.F.

    2012-01-01

    Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly in...

  7. Auditory evoked potentials in patients with dementia of the Alzheimer type.

    Science.gov (United States)

    Grimes, A M; Grady, C L; Pikus, A

    1987-06-01

    Dementia of the Alzheimer type (DAT) disrupts the function of the central auditory nervous system as a result of temporal lobe pathology. Auditory brain stem response (ABR) and middle latency responses (MLR) were studied in a group of patients with DAT to determine whether a correlate of dementia existed in these electrophysiological potentials. Comparison of absolute and interwave latencies on ABR, and absolute latency and amplitude of the MLR in patients with DAT and normal aged controls showed no significant differences between groups for any measure. Further, no relationship with degree of dementia or temporal lobe involvement, as assessed through dichotic speech recognition studies, and auditory evoked potentials could be demonstrated. It was concluded that the temporal lobe atrophy and hypometabolism seen in DAT is not generally sufficient to disrupt the generating of ABR and MLR potentials; however, slow cortical and cognitive evoked potentials may be more sensitive to central auditory nervous system impairment in DAT.

  8. Human cerebrocortical potentials evoked by stimulation of the dorsal nerve of the penis.

    Science.gov (United States)

    Bradley, W E; Farrell, D F; Ojemann, G A

    1998-01-01

    Cortical evoked potentials resulting from stimulation of the dorsal nerve of the penis (DNP) provide a unique opportunity to document the cortical localization of sexual sensory representation in man. The DNP supplies sensory axons to the major portion of the human phallus, including the penile shaft and glans. Animal and human studies indicate that this nerve plays a crucial role in erection and ejaculation. Direct cortical evoked responses to DNP electrical stimulation were recorded in patients undergoing preoperative evaluation for resection of epileptic foci. These studies provided evidence that the primary sensory cortex contains a large area of cortex devoted to the afferent fibers of the DNP and that the sensory field is in a different location than previously described. The location and distribution of this response indicated the need for revision of the traditional concept of the sensory cortical homunculus.

  9. Enablers and constrainers to participation

    DEFF Research Database (Denmark)

    Desjardins, Richard; Milana, Marcella

    2007-01-01

    as to construct a tool for analyzing the targeting of adult learning policy, with regard to both its coverage and expected consequences. Our aim is to develop a means for a more in-depth analysis of the match-mismatch of public policy and persisting constraints to participation.......This paper briefly reviews some of evidence on participation patterns in Nordic countries and some of the defining parameters that may explain the observations. This is done in a comparative perspective by contrasting results from the 2003 Eurobarometer data between Nordic countries and a handful...... of non-Nordic countries. An emphasis is placed on the constraining and enabling elements to participation and how these may explain why certain groups participate more or less than others. A central question of interest to this paper is to what extent does (can) government intervention interact...

  10. Constrained Allocation Flux Balance Analysis

    CERN Document Server

    Mori, Matteo; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferr...

  11. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  12. Increased Evoked Potentials to Arousing Auditory Stimuli during Sleep: Implication for the Understanding of Dream Recall

    OpenAIRE

    Vallat, Raphael; Lajnef, Tarek; Eichenlaub, Jean-Baptiste; Berthomier, Christian; Jerbi, Karim; Morlet, Dominique; Ruby, Perrine M.

    2017-01-01

    High dream recallers (HR) show a larger brain reactivity to auditory stimuli during wakefulness and sleep as compared to low dream recallers (LR) and also more intra-sleep wakefulness (ISW), but no other modification of the sleep macrostructure. To further understand the possible causal link between brain responses, ISW and dream recall, we investigated the sleep microstructure of HR and LR, and tested whether the amplitude of auditory evoked potentials (AEPs) was predictive of arousing react...

  13. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    OpenAIRE

    Vincis; Lagier; van de Ville; Rodriguez; Carleton

    2015-01-01

    Summary 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 ...

  14. Gain and phase of perceived virtual rotation evoked by electrical vestibular stimuli

    OpenAIRE

    Ryan M Peters; Rasman, Brandon G.; Inglis, J. Timothy; Blouin, Jean-Sébastien

    2015-01-01

    Galvanic vestibular stimulation (GVS) evokes a perception of rotation; however, very few quantitative data exist on the matter. We performed psychophysical experiments on virtual rotations experienced when binaural bipolar electrical stimulation is applied over the mastoids. We also performed analogous real whole body yaw rotation experiments, allowing us to compare the frequency response of vestibular perception with (real) and without (virtual) natural mechanical stimulation of the semicirc...

  15. Sex differences in formalin-evoked primary afferent release of substance P.

    Science.gov (United States)

    Nazarian, A; Tenayuca, J M; Almasarweh, F; Armendariz, A; Are, D

    2014-01-01

    Sex differences in pain have been well documented; however, the mechanisms involved remain to be elucidated. The present study examined whether sex differences exist in the functioning of primary afferent fibres by assessing formalin-evoked release of substance P by way of neurokinin 1 receptor (NK1r) internalization. The study also investigated whether the observed effects would be oestradiol-sensitive. Intact and gonadectomized male and female rats were given intraplantar formalin and then euthanized either 5 or 30 min later, representing phase 1 or 2 of the formalin response, respectively. In a subsequent experiment, ovariectomized females received oestradiol prior to formalin administration. Lastly, formalin-evoked NK1r internalization was assessed across the female oestrous cycle. Intraplantar formalin evoked significant NK1r internalization, during phase 1 and 2, in both males and females. During phase 1, no differences in NK1r internalization were detected between males or females, regardless of the gonadal status. In contrast, during phase 2, intact females exhibited greater NK1r internalization than intact males. Moreover, ovariectomy reduced NK1r internalization as compared to intact females, whereas castration had no effect as compared to intact males. Oestradiol supplementation in ovariectomized females increased NK1r internalization to levels observed in intact females. Formalin-evoked NK1r internalization did not differ across the oestrous cycle. These findings suggest that oestradiol mediates sex differences in formalin-evoked substance P release, which may contribute to a differential development of central sensitization and pain behaviours in males and females. © 2013 European Pain Federation - EFIC®

  16. The bed nucleus of the stria terminalis is critical for anxiety-related behavior evoked by CO2 and acidosis.

    Science.gov (United States)

    Taugher, Rebecca J; Lu, Yuan; Wang, Yimo; Kreple, Collin J; Ghobbeh, Ali; Fan, Rong; Sowers, Levi P; Wemmie, John A

    2014-07-30

    Carbon dioxide (CO2) inhalation lowers brain pH and induces anxiety, fear, and panic responses in humans. In mice, CO2 produces freezing and avoidance behavior that has been suggested to depend on the amygdala. However, a recent study in humans with bilateral amygdala lesions revealed that CO2 can trigger fear and panic even in the absence of amygdalae, suggesting the importance of extra-amygdalar brain structures. Because the bed nucleus of the stria terminalis (BNST) contributes to fear- and anxiety-related behaviors and expresses acid-sensing ion channel-1A (ASIC1A), we hypothesized that the BNST plays an important role in CO2-evoked fear-related behaviors in mice. We found that BNST lesions decreased both CO2-evoked freezing and CO2-conditioned place avoidance. In addition, we found that CO2 inhalation caused BNST acidosis and that acidosis was sufficient to depolarize BNST neurons and induce freezing behavior; both responses depended on ASIC1A. Finally, disrupting Asic1a specifically in the BNST reduced CO2-evoked freezing, whereas virus-vector-mediated expression of ASIC1A in the BNST of Asic1a(-/-) and Asic1a(+/+) mice increased CO2-evoked freezing. Together, these findings identify the BNST as an extra-amygdalar fear circuit structure important in CO2-evoked fear-related behavior. Copyright © 2014 the authors 0270-6474/14/3410247-09$15.00/0.

  17. Evoked cavernous activity: measuring penile autonomic innervation following pelvic surgery.

    Science.gov (United States)

    Yilmaz, U; Ellis, W; Lange, P; Yang, C

    2006-01-01

    To assess cavernous nerve integrity, we measured evoked cavernous activity (ECA) in 16 men who underwent nerve sparing radical prostatectomy (NS group) and 11 men who underwent non-nerve-sparing surgery (non-NS group). The right 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. All subjects had recordable SSR, and all subjects following nerve-sparing radical prostatectomy had reproducible ECA. Of the 11 non-NS subjects, eight had no response, indicating interrupted corporal innervation. Three subjects had reproducible ECA, one of whom had a very late latency, suggesting residual innervation was present. The mean latencies of ECA were similar to foot SSR mean latencies (P>0.05), but not to hand SSR latencies. The non-NS group was significantly different from the NS group for the presence of ECA (PECA is a viable method of evaluating the autonomic innervation of the penis.

  18. Vestibular evoked myogenic potentials in patients with ankylosing spondylitis.

    Science.gov (United States)

    Özgür, Abdulkadir; Serdaroğlu Beyazal, Münevver; Terzi, Suat; Coşkun, Zerrin Özergin; Dursun, Engin

    2016-10-01

    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.

  19. Ocular Vestibular Evoked Myogenic Potentials: Where Are We Now?

    Science.gov (United States)

    Dlugaiczyk, Julia

    2017-12-01

    Over the last decade, ocular vestibular evoked myogenic potentials (oVEMPs) have evolved as a new clinical test for dynamic otolith (predominantly utricular) function. The aim of this review is to give an update on the neurophysiological foundations of oVEMPs and their implications for recording and interpreting oVEMP responses in clinical practice. Different lines of anatomical, neurophysiological, and clinical evidence support the notion that oVEMPs measure predominantly contralateral utricular function, while cervical cVEMPs are an indicator of ipsilateral saccular function. Bone-conducted vibration (BCV) in the midline of the forehead at the hairline (Fz) or unilateral air-conducted sound (ACS) are commonly used as stimuli for oVEMPs. It is recommended to apply short stimuli with short rise times for obtaining optimal oVEMP responses. Finally, this review summarizes the clinical application and interpretation of oVEMPs, particularly for vestibular neuritis, Ménière's disease, superior canal dehiscence and "challenging" patients.

  20. 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

    2009-01-01

    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

  1. EEG sources of noise in intraoperative somatosensory evoked potential monitoring during propofol anesthesia.

    Science.gov (United States)

    Joutsen, Atte; Puumala, Pasi; Lyytikäinen, Leo-Pekka; Pajulo, Olli; Etelämäki, Aira; Eskola, Hannu; Jäntti, Ville

    2009-08-01

    It was hypothesized that somato- sensory evoked potentials can be achieved faster by selective averaging during periods of low spontaneous electroen- cephalographic (EEG) activity. We analyzed the components of EEG that decrease the signal-to-noise ratio of somatosensory evoked potential (SEP) recordings during propofol anesthesia. Patient EEGs were recorded with a high sampling frequency during deep anesthesia, when EEGs were in burst suppression. EEGs were segmented visually into bursts, spindles, suppressions, and artifacts. Tibial somatosensory evoked potentials (tSEPs) were averaged offline separately for burst, suppression, and spindle segments using a signal bandwidth of 30-200 Hz. Averages achieved with 2, 4, 8, 16, 64, 128, and 256 responses were compared both visually, and by calculating the signal-to-noise ratios. During bursts and spindles, the noise levels were similar and significantly higher than during suppressions. Four to eight times more responses had to be averaged during bursts and spindles than during suppressions in order to achieve a similar response quality. Averaging selectively during suppressions can therefore yield reliable tSEPs in approximately one-fifth of the time required during bursts. The major source of EEG noise in tSEP recordings is the mixed frequency activity of the slow waves of bursts that occur during propofol anesthesia. Spindles also have frequency components that increase noise levels, but these are less important, as the number of spindles is fewer. The fastest way to obtain reliable tSEPs is by averaging selectively during suppressions.

  2. Visually evoked spiking evolves while spontaneous ongoing dynamics persist

    Directory of Open Access Journals (Sweden)

    Raoul eHuys

    2016-01-01

    Full Text Available Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix. The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2-3.

  3. Evoked otoacoustic emissions behaviour in retinitis pigmentosa.

    Science.gov (United States)

    Fiore, C; Cagini, C; Menduno, P; Toniassoni, I; Desantis, A; Pennacchi, A; Ricci, G; Molini, E

    1994-01-01

    The hearing function was studied in 26 patients affected by retinitis pigmentosa (RP) and in their relatives. Sixteen patients showed bilateral normal hearing when examined with traditional audiometric methods. In these normoacusic patients evoked otoacoustic emissions (EOE) have been studied. The EOE offer a unique opportunity to measure objectively the function of outer hair cells: they record the amplitude of the energy produced by the outer hair cells of the coclea following an acoustic stimulation. The data have been statistically compared, using the Student's t-test, with those obtained in a homogeneous control-group of normal subjects. In normoacusic subjects with RP the average values of EOE intensity are statistically lower than those of normal subjects in 64 of the 127 frequency bands examined. Moreover, the distribution of the EOE in patients with retinitis pigmentosa proved to be more discontinous than that observed in the normal subjects. The EOE recorded in 14 normoacusic relatives show in some cases small anomalies but the data, on account of the limited sample group, cannot be statistically evaluated. Therefore a subclinical alteration of the Organ of Corti is found in 100% of the patients affected by RP, although they appear to be normoacusic to usual audiometric tests.

  4. Transient evoked otoacoustic emissions in rock musicians.

    Science.gov (United States)

    Høydal, Erik Harry; Lein Størmer, Carl Christian; Laukli, Einar; Stenklev, Niels Christian

    2017-09-01

    Our focus in this study was the assessment of transient evoked otoacoustic emissions (TEOAEs) in a large group of rock musicians. A further objective was to analyse tinnitus among rock musicians as related to TEOAEs. The study was a cross-sectional survey of rock musicians selected at random. A control group was included at random for comparison. We recruited 111 musicians and a control group of 40 non-musicians. Testing was conducted by using clinical examination, pure tone audiometry, TEOAEs and a questionnaire. TEOAE SNR in the half-octave frequency band centred on 4 kHz was significantly lower bilaterally in musicians than controls. This effect was strongly predicted by age and pure-tone hearing threshold levels in the 3-6 kHz range. Bilateral hearing thresholds were significantly higher at 6 kHz in musicians. Twenty percent of the musicians had permanent tinnitus. There was no association between the TEOAE parameters and permanent tinnitus. Our results suggest an incipient hearing loss at 6 kHz in rock musicians. Loss of TEOAE SNR in the 4 kHz half-octave frequency band was observed, but it was related to higher mean 3-6 kHz hearing thresholds and age. A large proportion of rock musicians have permanent tinnitus.

  5. Constrained Laboratory vs. Unconstrained Steering-Induced Rollover Crash Tests.

    Science.gov (United States)

    Kerrigan, Jason R; Toczyski, Jacek; Roberts, Carolyn; Zhang, Qi; Clauser, Mark

    2015-01-01

    The goal of this study was to evaluate how well an in-laboratory rollover crash test methodology that constrains vehicle motion can reproduce the dynamics of unconstrained full-scale steering-induced rollover crash tests in sand. Data from previously-published unconstrained steering-induced rollover crash tests using a full-size pickup and mid-sized sedan were analyzed to determine vehicle-to-ground impact conditions and kinematic response of the vehicles throughout the tests. Then, a pair of replicate vehicles were prepared to match the inertial properties of the steering-induced test vehicles and configured to record dynamic roof structure deformations and kinematic response. Both vehicles experienced greater increases in roll-axis angular velocities in the unconstrained tests than in the constrained tests; however, the increases that occurred during the trailing side roof interaction were nearly identical between tests for both vehicles. Both vehicles experienced linear accelerations in the constrained tests that were similar to those in the unconstrained tests, but the pickup, in particular, had accelerations that were matched in magnitude, timing, and duration very closely between the two test types. Deformations in the truck test were higher in the constrained than the unconstrained, and deformations in the sedan were greater in the unconstrained than the constrained as a result of constraints of the test fixture, and differences in impact velocity for the trailing side. The results of the current study suggest that in-laboratory rollover tests can be used to simulate the injury-causing portions of unconstrained rollover crashes. To date, such a demonstration has not yet been published in the open literature. This study did, however, show that road surface can affect vehicle response in a way that may not be able to be mimicked in the laboratory. Lastly, this study showed that configuring the in-laboratory tests to match the leading-side touchdown conditions

  6. The vestibular evoked-potential profile of Ménière's disease.

    Science.gov (United States)

    Taylor, Rachael L; Wijewardene, Ayanthi A; Gibson, William P R; Black, Deborah A; Halmagyi, G Michael; Welgampola, Miriam S

    2011-06-01

    To define the ocular and cervical vestibular evoked myogenic potential (oVEMP and cVEMP) profile in Ménière's Disease (MD), we studied air-conducted (AC) sound and bone-conducted vibration (BCV)-evoked responses in 77 patients and 35 controls. oVEMPs were recorded from unrectified infra-orbital surface electromyography (EMG) during upward gaze. cVEMPs were recorded from rectified and unrectified sternocleidomastoid EMG during head elevation against gravity. Responses to AC clicks delivered via headphones and BC forehead taps delivered with a mini-shaker (bone-conduction vibrator) and a triggered tendon-hammer were recorded. In clinically definite unilateral MD (n=60), the prevalence of unilateral VEMP abnormalities was 50.0%, 10.2% and 11.9% for click, minitap and tendon-hammer evoked oVEMPs, 40.0%, 22.8% and 10.7% for click, minitap and tendon-hammer evoked cVEMPs. The most commonly observed profile was abnormality to AC stimulation alone (33.3%), followed by abnormalities to both AC and BCV stimuli (26.7%). Isolated abnormalities to BCV stimuli were rare (5%) and limited to the minitap cVEMP. The prevalence of abnormalities for each of the AC VEMPs was significantly higher than for any one BCV VEMP. For click cVEMP, click oVEMP and minitap cVEMP, average Reflex Asymmetry Ratios (AR) were significantly higher in MD compared with controls. Test results for AC cVEMP, AC oVEMP, minitap cVEMP and caloric asymmetry were significantly correlated with hearing loss. Predominance of abnormalities in oVEMP and cVEMP responses to AC sound is characteristic of MD and indicative of saccular involvement. This pattern of VEMP abnormalities may enable separation of Ménière's disease from other peripheral vestibulopathies. Copyright © 2010 International Federation of Clinical Neurophysiology. All rights reserved.

  7. Task-evoked brain functional magnetic susceptibility mapping by independent component analysis (χICA).

    Science.gov (United States)

    Chen, Zikuan; Calhoun, Vince D

    2016-03-01

    Conventionally, independent component analysis (ICA) is performed on an fMRI magnitude dataset to analyze brain functional mapping (AICA). By solving the inverse problem of fMRI, we can reconstruct the brain magnetic susceptibility (χ) functional states. Upon the reconstructed χ dataspace, we propose an ICA-based brain functional χ mapping method (χICA) to extract task-evoked brain functional map. A complex division algorithm is applied to a timeseries of fMRI phase images to extract temporal phase changes (relative to an OFF-state snapshot). A computed inverse MRI (CIMRI) model is used to reconstruct a 4D brain χ response dataset. χICA is implemented by applying a spatial InfoMax ICA algorithm to the reconstructed 4D χ dataspace. With finger-tapping experiments on a 7T system, the χICA-extracted χ-depicted functional map is similar to the SPM-inferred functional χ map by a spatial correlation of 0.67 ± 0.05. In comparison, the AICA-extracted magnitude-depicted map is correlated with the SPM magnitude map by 0.81 ± 0.05. The understanding of the inferiority of χICA to AICA for task-evoked functional map is an ongoing research topic. For task-evoked brain functional mapping, we compare the data-driven ICA method with the task-correlated SPM method. In particular, we compare χICA with AICA for extracting task-correlated timecourses and functional maps. χICA can extract a χ-depicted task-evoked brain functional map from a reconstructed χ dataspace without the knowledge about brain hemodynamic responses. The χICA-extracted brain functional χ map reveals a bidirectional BOLD response pattern that is unavailable (or different) from AICA. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Torque decrease during submaximal evoked contractions of the quadriceps muscle is linked not only to muscle fatigue.

    Science.gov (United States)

    Matkowski, Boris; Lepers, Romuald; Martin, Alain

    2015-05-01

    The aim of this study was to analyze the neuromuscular mechanisms involved in the torque decrease induced by submaximal electromyostimulation (EMS) of the quadriceps muscle. It was hypothesized that torque decrease after EMS would reflect the fatigability of the activated motor units (MUs), but also a reduction in the number of MUs recruited as a result of changes in axonal excitability threshold. Two experiments were performed on 20 men to analyze 1) the supramaximal twitch superimposed and evoked at rest during EMS (Experiment 1, n = 9) and 2) the twitch response and torque-frequency relation of the MUs activated by EMS (Experiment 2, n = 11). Torque loss was assessed by 15 EMS-evoked contractions (50 Hz; 6 s on/6 s off), elicited at a constant intensity that evoked 20% of the maximal voluntary contraction (MVC) torque. The same stimulation intensity delivered over the muscles was used to induce the torque-frequency relation and the single electrical pulse evoked after each EMS contraction (Experiment 2). In Experiment 1, supramaximal twitch was induced by femoral nerve stimulation. Torque decreased by ~60% during EMS-evoked contractions and by only ~18% during MVCs. This was accompanied by a rightward shift of the torque-frequency relation of MUs activated and an increase of the ratio between the superimposed and posttetanic maximal twitch evoked during EMS contraction. These findings suggest that the torque decrease observed during submaximal EMS-evoked contractions involved muscular mechanisms but also a reduction in the number of MUs recruited due to changes in axonal excitability. Copyright © 2015 the American Physiological Society.

  9. Evoked potentials and head injury. 1. Rating of evoked potential abnormality.

    Science.gov (United States)

    Rappaport, M; Hall, K; Hopkins, H K; Belleza, T

    1981-10-01

    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. Emotional Response Deficits in Schizophrenia: Insights From Affective Science

    National Research Council Canada - National Science Library

    Kring, Ann M; Moran, Erin K

    2008-01-01

    ... our understanding of emotional response deficits in schizophrenia. We review naturalistic studies and elicitation studies that evoke emotion responses among participants, including emotion expression, experience, and autonomic physiology...

  11. Wavelet library for constrained devices

    Science.gov (United States)

    Ehlers, Johan Hendrik; Jassim, Sabah A.

    2007-04-01

    The wavelet transform is a powerful tool for image and video processing, useful in a range of applications. This paper is concerned with the efficiency of a certain fast-wavelet-transform (FWT) implementation and several wavelet filters, more suitable for constrained devices. Such constraints are typically found on mobile (cell) phones or personal digital assistants (PDA). These constraints can be a combination of; limited memory, slow floating point operations (compared to integer operations, most often as a result of no hardware support) and limited local storage. Yet these devices are burdened with demanding tasks such as processing a live video or audio signal through on-board capturing sensors. In this paper we present a new wavelet software library, HeatWave, that can be used efficiently for image/video processing/analysis tasks on mobile phones and PDA's. We will demonstrate that HeatWave is suitable for realtime applications with fine control and range to suit transform demands. We shall present experimental results to substantiate these claims. Finally this library is intended to be of real use and applied, hence we considered several well known and common embedded operating system platform differences; such as a lack of common routines or functions, stack limitations, etc. This makes HeatWave suitable for a range of applications and research projects.

  12. Sensory deficits of a nerve root lesion can be objectively documented by somatosensory evoked potentials elicited by painful infrared laser stimulations: a case study.

    OpenAIRE

    Lorenz, J.; HANSEN, H. C.; K. Kunze; Bromm, B

    1996-01-01

    Somatosensory evoked potentials (SEPs) in response to painful laser stimuli were measured in a patient with a unilateral sensory deficit due to radiculopathy at cervical levels C7 and C8. Laser evoked potentials (LEPs) were compared with SEPs using standard electrical stimulation of median and ulnar nerves at the wrist and mechanical stimulation of the fingertips by means of a mechanical stimulator. Early and late ulnar and median nerve SEPs were normal. Mechanical stimulation resulted in w s...

  13. Electrocochleography potentials evoked by condensation and rarefaction clicks independently derived by a new numerical filtering approach.

    Science.gov (United States)

    Sparacino, G; Milani, S; Magnavita, V; Arslan, E

    2000-01-01

    The cochlear microphonic potential (CM) and the compound action potential (CAP) cannot be measured separately but only in combination. In the literature their individual estimates are conventionally recovered by the so-called CM cancellation technique. This method averages the potential obtained in response to rarefaction and condensation clicks under the assumption that changing the polarity of the clicks only affects the CM sign and does not alter the CAP in any way. However, both theory and evidence suggest that these hypotheses can be critical. In addition, recent contributions in the electrocochleography (ECochG) literature suggested that assessing the influence of stimulus polarity on the evoked CAP may constitute an indicator of clinical usefulness which the CM cancellation method cannot supply. In this work we propose a new algorithm to estimate the cochlear potentials evoked from positive clicks, CAP+ and CM+, and those evoked from negative clicks, CAP- and CM-, by processing the same kind and amount of data employed in the CM cancellation method. The application to real data taken from 3 subjects exhibiting quantitatively and qualitatively different ECochG responses at various levels of stimulation intensity is presented. In addition, simulated problems where the true CAP and CM are known are studied to permit a fair assessment of the proposed technique. Results suggest that the new algorithm is potentially able to point out small differences between CAP+ and CAP-. This encourages its further employment on a larger scale. Copyright 2000 S. Karger AG, Basel

  14. Neonatal Cortical Auditory Evoked Potentials Are Affected by Clinical Conditions Occurring in Early Prematurity.

    Science.gov (United States)

    Suppiej, Agnese; Cainelli, Elisa; Cappellari, Ambra; Ermani, Mario; Sartori, Stefano; Bisiacchi, Patrizia S

    2015-10-01

    Cortical auditory evoked potentials may serve as an early indicator of developmental problems in the auditory cortex. The aim of the study was to determine the effect on neonatal cortical auditory processing of clinical conditions occurring in early prematurity. Sixty-seven preterm infants born at 29 weeks mean gestational age (range, 23-34 weeks) were recorded at a mean postconception age of 35 weeks, before discharge from the third level neonatal intensive care unit. The average of 330 responses to standard 1000 Hz pure tones delivered in an oddball paradigm was recorded at frontal location. Data of 45 of 67 recruited premature infants were available for analysis. Mean amplitudes calculated from the data points of 30 milliseconds centered on P1 and N2 peaks in the waveforms of each subject were measured. The effect of perinatal clinical factors on cortical auditory evoked responses was evaluated. The amplitude of P1 component was significantly lower in infants with bronco-pulmonary dysplasia (P = 0.004) and retinopathy of prematurity (P = 0.03). The multivariate analysis, done to evaluate the relative weight of gestational age and bronco-pulmonary dysplasia and/or retinopathy of prematurity on cortical auditory evoked potentials components, showed an effect of clinical factors on P1 (P = 0.005) and of gestational age on N2 (P = 0.02). Cortical auditory processing seems to be influenced by clinical conditions complicating extremely preterm birth.

  15. Towards a neural basis of music-evoked emotions.

    Science.gov (United States)

    Koelsch, Stefan

    2010-03-01

    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. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Distraction Reduces Both Early and Late Electrocutaneous Stimulus Evoked Potentials

    NARCIS (Netherlands)

    Blom, J.H.G.; Wiering, Caro H.; van der Lubbe, Robert Henricus Johannes

    2012-01-01

    Previous electroencephalography studies revealed mixed effects of sustained distraction on early negative and later positive event-related potential components evoked by electrocutaneous stimuli. In our study we further examined the influence of sustained distraction to clarify these discrepancies.

  17. Transcranial electrical motor-evoked potential monitoring during surgery for spinal deformity - A study of 145 patients

    NARCIS (Netherlands)

    Langeloo, DD; Lelivelt, A; Journee, HL; Slappendel, R; de Kleuver, M

    2003-01-01

    Study Design. A descriptive historic cohort study was conducted. Objectives. To determine intraoperative response amplitude criteria for transcranial electrical motor-evoked potential monitoring that warn of neurologic damage, and to determine the additional value of monitoring six instead of two

  18. Bifurcation Of Olfactory Bulb Neuron Biophysics During Odor-Evoked Subthreshold Oscillation.

    Science.gov (United States)

    Kubota, Yoshihisa; Bower, James

    1998-03-01

    The Role of odor-evoked subthreshold oscillations in the olfactory bulb was studied using bifurcation and impedance analysis in a mathematical model of mitral cells which are the primary neuron of the olfactory bulb. Mathematical analyses of a reduced realistic model of an olfactory mitral cell suggests that these cells undergo a bifurcation from nonspecific passive response to voltage-dependent, low-frequency specific resonance during subthreshold bulbar oscillations. We propose that a partial role of odor-evoked subthreshold oscillations may be to bring the biophysical state variables of mitral cells into region of phase space where neurons become highly resonant to peripheral afferent as well as centrifugal inputs despite of the heterogeneity in mitral cell biophysics prior to odor presentation.

  19. Evoked corticospinal output to the human scalene muscles is altered by lung volume.

    Science.gov (United States)

    Hudson, Anna L; Taylor, Janet L; Anand, Ashima; Gandevia, Simon C; Butler, Jane E

    2012-03-15

    Increases in lung volume inhibit the inspiratory output from the medulla, but the effect of lung inflation on the voluntary control of breathing in humans is not known. We tested corticospinal excitability using transcranial magnetic stimulation (TMS) to evoke a response in the scalene muscles. TMS was delivered at rest at three different lung volumes between functional residual capacity (FRC) and total lung capacity (TLC) during incremental inspiratory and incremental expiratory manoeuvres. Motor evoked potentials (MEPs) in scalenes were ∼50% larger at a high lung volume (FRC+∼90% inspiratory capacity [IC]) compared to lower lung volumes (FRC and FRC+∼40% IC) in both inspiratory and expiratory manoeuvres (plung inflation on the automatic and voluntary control of breathing in humans. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Sensory-Evoked Intrinsic Imaging Signals in the Olfactory Bulb Are Independent of Neurovascular Coupling

    Directory of Open Access Journals (Sweden)

    Roberto Vincis

    2015-07-01

    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.

  1. Constrained Peptides as Miniature Protein Structures

    Science.gov (United States)

    Yin, Hang

    2012-01-01

    This paper discusses the recent developments of protein engineering using both covalent and noncovalent bonds to constrain peptides, forcing them into designed protein secondary structures. These constrained peptides subsequently can be used as peptidomimetics for biological functions such as regulations of protein-protein interactions. PMID:25969758

  2. Modeling the microstructural evolution during constrained sintering

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Frandsen, Henrik Lund; Pryds, Nini

    A mesoscale numerical model able to simulate solid state constrained sintering is presented. The model couples an existing kinetic Monte Carlo (kMC) model for free sintering with a finite element method for calculating stresses. The sintering behavior of a sample constrained by a rigid substrate...

  3. Early event related fields during visually evoked pain anticipation.

    Science.gov (United States)

    Gopalakrishnan, Raghavan; Burgess, Richard C; Plow, Ela B; Floden, Darlene P; Machado, Andre G

    2016-03-01

    Pain experience is not only a function of somatosensory inputs. Rather, it is strongly influenced by cognitive and affective pathways. Pain anticipatory phenomena, an important limitation to rehabilitative efforts in the chronic state, are processed by associative and limbic networks, along with primary sensory cortices. Characterization of neurophysiological correlates of pain anticipation, particularly during very early stages of neural processing is critical for development of therapeutic interventions. Here, we utilized magnetoencephalography to study early event-related fields (ERFs) in healthy subjects exposed to a 3 s visual countdown task that preceded a painful stimulus, a non-painful stimulus or no stimulus. We found that the first countdown cue, but not the last cue, evoked critical ERFs signaling anticipation, attention and alertness to the noxious stimuli. Further, we found that P2 and N2 components were significantly different in response to first-cues that signaled incoming painful stimuli when compared to non-painful or no stimuli. The findings indicate that early ERFs are relevant neural substrates of pain anticipatory phenomena and could be potentially serve as biomarkers. These measures could assist in the development of neurostimulation approaches aimed at curbing the negative effects of pain anticipation during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Vestibular evoked myogenic potential findings in multiple sclerosis.

    Science.gov (United States)

    Escorihuela García, Vicente; Llópez Carratalá, Ignacio; Orts Alborch, Miguel; Marco Algarra, Jaime

    2013-01-01

    Multiple sclerosis is an inflammatory disease involving the occurrence of demyelinating, chronic neurodegenerative lesions in the central nervous system. We studied vestibular evoked myogenic potentials (VEMPs) in this pathology, to allow us to evaluate the saccule, inferior vestibular nerve and vestibular-spinal pathway non-invasively. There were 23 patients diagnosed with multiple sclerosis who underwent VEMP recordings, comparing our results with a control group consisting of 35 healthy subjects. We registered p13 and n23 wave latencies, interaural amplitude difference and asymmetry ratio between both ears. Subjects also underwent an otoscopy and audiometric examination. The prolongation of p13 and n23 wave latencies was the most notable characteristic, with a mean p13 wave latency of 19.53 milliseconds and a mean latency of 30.06 milliseconds for n23. In contrast, the asymmetry index showed no significant differences with our control group. In case of multiple sclerosis, the prolongation of the p13 and n23 VEMP wave latencies is a feature that has been attributed to slowing of conduction by demyelination of the vestibular-spinal pathway. In this regard, alteration of the response or lack thereof in these potentials has a locator value of injury to the lower brainstem. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  5. Humor drawings evoked temporal and spectral EEG processes

    Science.gov (United States)

    Kuo, Hsien-Chu; Chuang, Shang-Wen

    2017-01-01

    Abstract The study aimed to explore the humor processing elicited through the manipulation of artistic drawings. Using the Comprehension–Elaboration Theory of humor as the main research background, the experiment manipulated the head portraits of celebrities based on the independent variables of facial deformation (large/small) and addition of affective features (positive/negative). A 64-channel electroencephalography was recorded in 30 participants while viewing the incongruous drawings of celebrities. The electroencephalography temporal and spectral responses were measured during the three stages of humor which included incongruity detection, incongruity comprehension and elaboration of humor. Analysis of event-related potentials indicated that for humorous vs non-humorous drawings, facial deformation and the addition of affective features significantly affected the degree of humor elicited, specifically: large > small deformation; negative > positive affective features. The N170, N270, N400, N600-800 and N900-1200 components showed significant differences, particularly in the right prefrontal and frontal regions. Analysis of event-related spectral perturbation showed significant differences in the theta band evoked in the anterior cingulate cortex, parietal region and posterior cingulate cortex; and in the alpha and beta bands in the motor areas. These regions are involved in emotional processing, memory retrieval, and laughter and feelings of amusement induced by elaboration of the situation. PMID:28402573

  6. Effect of neck flexion on somatosensory and motor evoked potentials in Hirayama disease.

    Science.gov (United States)

    Abraham, A; Gotkine, M; Drory, V E; Blumen, S C

    2013-11-15

    Hirayama disease (HD) is a rare motor disorder mainly affecting young men, characterized by atrophy and weakness of forearm and hand muscles corresponding to a C7-T1 myotome distribution. The weakness is usually unilateral or asymmetric and progression usually stops within several years. The etiology of HD is not well understood. One hypothesis, mainly based on MRI findings, is that the weakness is a consequence of cervical flexion myelopathy. The aim of this study was to explore the function of corticospinal and ascending somatosensory pathways during neck flexion using evoked responses. 15 men with HD and 7 age-matched control male subjects underwent somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) studies with the neck in neutral position and fully flexed. SSEP studies included electrical stimulation of median and ulnar nerves at the wrist, and tibial nerve at the ankle with recording over the ipsilateral Erb's point, cervical spine, and contralateral sensory cortex. MEP recordings were obtained by magnetic stimulation of the motor cortex and the cervical lower spinal roots; the evoked responses were recorded from the contralateral thenar and abductor hallucis muscles. MEP recordings demonstrated significant lower amplitudes, and slightly prolonged latencies in HD patients on cervical stimulation, compared to control subjects. During neck flexion, MEP studies also demonstrated a statistically significant drop in mean upper limb amplitude on cervical stimulation in HD patients, as well as in control subjects, although to a lesser degree. In contrast, no significant differences were found in SSEP studies in HD patients compared to control subjects, or between neutral and flexed position in these groups. The study shows a negative effect of cervical flexion on MEP amplitudes in HD patients as well as in control subjects, requiring more studies to investigate its significance. Neck flexion did not have an influence on any SSEP parameters in

  7. Order-constrained linear optimization.

    Science.gov (United States)

    Tidwell, Joe W; Dougherty, Michael R; Chrabaszcz, Jeffrey S; Thomas, Rick P

    2017-11-01

    Despite the fact that data and theories in the social, behavioural, and health sciences are often represented on an ordinal scale, there has been relatively little emphasis on modelling ordinal properties. The most common analytic framework used in psychological science is the general linear model, whose variants include ANOVA, MANOVA, and ordinary linear regression. While these methods are designed to provide the best fit to the metric properties of the data, they are not designed to maximally model ordinal properties. In this paper, we develop an order-constrained linear least-squares (OCLO) optimization algorithm that maximizes the linear least-squares fit to the data conditional on maximizing the ordinal fit based on Kendall's τ. The algorithm builds on the maximum rank correlation estimator (Han, 1987, Journal of Econometrics, 35, 303) and the general monotone model (Dougherty & Thomas, 2012, Psychological Review, 119, 321). Analyses of simulated data indicate that when modelling data that adhere to the assumptions of ordinary least squares, OCLO shows minimal bias, little increase in variance, and almost no loss in out-of-sample predictive accuracy. In contrast, under conditions in which data include a small number of extreme scores (fat-tailed distributions), OCLO shows less bias and variance, and substantially better out-of-sample predictive accuracy, even when the outliers are removed. We show that the advantages of OCLO over ordinary least squares in predicting new observations hold across a variety of scenarios in which researchers must decide to retain or eliminate extreme scores when fitting data. © 2017 The British Psychological Society.

  8. Singular divergence instability thresholds of kinematically constrained circulatory systems

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, O.N., E-mail: o.kirillov@hzdr.de [Magnetohydrodynamics Division, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden (Germany); Challamel, N. [University of South Brittany, LIMATB, Lorient (France); Darve, F. [Laboratoire Sols Solides Structures, UJF-INPG-CNRS, Grenoble (France); Lerbet, J. [IBISC, Universite d' Evry Val d' Essone, 40 Rue Pelvoux, CE 1455 Courcouronnes, 91020 Evry Cedex (France); Nicot, F. [Cemagref, Unite de Recherche Erosion Torrentielle Neige et Avalanches, Grenoble (France)

    2014-01-10

    Static instability or divergence threshold of both potential and circulatory systems with kinematic constraints depends singularly on the constraints' coefficients. Particularly, the critical buckling load of the kinematically constrained Ziegler's pendulum as a function of two coefficients of the constraint is given by the Plücker conoid of degree n=2. This simple mechanical model exhibits a structural instability similar to that responsible for the Velikhov–Chandrasekhar paradox in the theory of magnetorotational instability.

  9. Effects of isoflurane and desflurane on neurogenic motor- and somatosensory-evoked potential monitoring for scoliosis surgery.

    Science.gov (United States)

    Bernard, J M; Péréon, Y; Fayet, G; Guihéneuc, P

    1996-11-01

    Most techniques used to monitor spinal cord tracts are sensitive to the effects of anesthesia, particularly to volatile anesthetic agents. The aim of this prospective study was to show that evoked potentials recorded from the peripheral nerves after spinal cord stimulation, so-called neurogenic motor evoked potentials, are resistant to clinical concentrations of isoflurane or desflurane, compared with somatosensory-evoked potentials. Twenty-three patients were studied during surgery to correct scoliosis. The background anesthetic consisted of a continuous infusion of propofol. Isoflurane (n = 12) or desflurane (n = 11) were then introduced to achieve 0.5 and 1.0 end-tidal minimum alveolar concentrations (MAC), both in 50% oxygen-nitrous oxide and in 100% oxygen. Somatosensory-evoked potentials were elicited and recorded using a standard method, defining cortical P40 and subcortical P29. Neurogenic motor-evoked potentials were elicited by electric stimulation of the spinal cord via needle electrodes placed by the surgeon in the rostral part of the surgical field. Responses were recorded from needle electrodes inserted in the right and left popliteal spaces close to the sciatic nerve. Stimulus intensity was adjusted to produce a supramaximal response; that is, an unchanged response in amplitude with subsequent increases in stimulus intensity. Measurements were obtained before introducing volatile agents and 20 min after obtaining a stable level of each concentration. Isoflurane and desflurane in both 50% oxygen-nitrous oxide and 100% oxygen were associated with a significant decrease in the amplitude and an increase in the latency of the cortical P40, whereas subcortical P29 latency did not vary significantly. Typical neurogenic motor-evoked potentials were obtained in all patients without volatile anesthetic agents, consisting of a biphasic wave, occurring 15 to 18 ms after stimulation, with an amplitude ranging from 1.3 to 4.1 microV. Latency or peak

  10. Suppressive interactions underlying visually evoked fixational saccades.

    Science.gov (United States)

    Wang, Helena X; Yuval-Greenberg, Shlomit; Heeger, David J

    2016-01-01

    Small saccades occur frequently during fixation, and are coupled to changes in visual stimulation and cognitive state. Neurophysiologically, fixational saccades reflect neural activity near the foveal region of a continuous visuomotor map. It is well known that competitive interactions between neurons within visuomotor maps contribute to target selection for large saccades. Here we asked how such interactions in visuomotor maps shape the rate and direction of small fixational saccades. We measured fixational saccades during periods of prolonged fixation while presenting pairs of visual stimuli (parafoveal: 0.8° eccentricity; peripheral: 5° eccentricity) of various contrasts. Fixational saccade direction was biased toward locations of parafoveal stimuli but not peripheral stimuli, ∼100-250ms following stimulus onset. The rate of fixational saccades toward parafoveal stimuli (congruent saccades) increased systematically with parafoveal stimulus contrast, and was suppressed by the simultaneous presentation of a peripheral stimulus. The suppression was best characterized as a combination of two processes: a subtractive suppression of the overall fixational saccade rate and a divisive suppression of the direction bias. These results reveal the nature of suppressive interactions within visuomotor maps and constrain models of the population code for fixational saccades. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Flash visual evoked potentials in preterm infants.

    Science.gov (United States)

    Feng, Jing-Jing; Wang, Wei-Ping; Guo, Shu-Juan; Liu, Zhi-Wei; Xu, Xiu

    2013-03-01

    To describe the development of flash visual evoked potentials (FVEPs) in preterm infants from 1 to 18 months and to determine if the maturation of FVEPs is similar to that of term infants. Longitudinal follow-up study. Twenty very low birth weight (VLBW) preterm infants, 42 low birth weight (LBW) preterm infants, and 41 term infants underwent FVEP recordings and neurodevelopmental examinations at 1, 3, 6, 9, 12, and 18 months of corrected and chronological ages. The FVEP recordings were carried out with the VikingQuest-IV neuroelectrophysiological device (VikingQuest, Nicolet, WI), and neurodevelopmental assessments were made by the Development Screen Test and Bayley Scales of Infant Development, Second Edition. At 1, 3, 6, and 9 months of age, neurodevelopment was measured with the Mental Index and Developmental Quotient. At 12 and 18 months, neurodevelopment was assessed using the Mental Developmental Index and Psychomotor Developmental Index. Two FVEP values were analyzed: the P2 amplitude (peak to peak from the preceding N2 wave) and the latency of the P2 wave. There was no significant difference for age-dependent decreased pattern of FVEP P2 latency between preterm infants and the control group. This pattern consisted of a rapid decrease in the first 6 months of life, a gradual decline from 6 to 12 months of age, and a steady reduction from 12 to 18 months of age. The P2 latencies were prolonged significantly at all 6 recorded times in the VLBW group compared with the controls and showed a delay in the LBW group at 1 and 3 months of corrected age. The maturation of P2 latency in LBW infants is similar to that of the controls at 3 months of corrected age, but the maturation of P2 latency in VLBW children remained delayed when compared with the controls until 18 months of corrected age. Although the FVEP development pattern of preterm infants was similar to that of healthy full-term infants, the former had deficits in visual electrophysiologic maturation

  12. Ghrelin regulates phasic dopamine and nucleus accumbens signaling evoked by food-predictive stimuli.

    Science.gov (United States)

    Cone, Jackson J; Roitman, Jamie D; Roitman, Mitchell F

    2015-06-01

    Environmental stimuli that signal food availability hold powerful sway over motivated behavior and promote feeding, in part, by activating the mesolimbic system. These food-predictive cues evoke brief (phasic) changes in nucleus accumbens (NAc) dopamine concentration and in the activity of individual NAc neurons. Phasic fluctuations in mesolimbic signaling have been directly linked to goal-directed behaviors, including behaviors elicited by food-predictive cues. Food-seeking behavior is also strongly influenced by physiological state (i.e., hunger vs. satiety). Ghrelin, a stomach hormone that crosses the blood-brain barrier, is linked to the perception of hunger and drives food intake, including intake potentiated by environmental cues. Notwithstanding, whether ghrelin regulates phasic mesolimbic signaling evoked by food-predictive stimuli is unknown. Here, rats underwent Pavlovian conditioning in which one cue predicted the delivery of rewarding food (CS+) and a second cue predicted nothing (CS-). After training, we measured the effect of ghrelin infused into the lateral ventricle (LV) on sub-second fluctuations in NAc dopamine using fast-scan cyclic voltammetry and individual NAc neuron activity using in vivo electrophysiology in separate groups of rats. LV ghrelin augmented both phasic dopamine and phasic increases in the activity of NAc neurons evoked by the CS+. Importantly, ghrelin did not affect the dopamine nor NAc neuron response to the CS-, suggesting that ghrelin selectively modulated mesolimbic signaling evoked by motivationally significant stimuli. These data demonstrate that ghrelin, a hunger signal linked to physiological state, can regulate cue-evoked mesolimbic signals that underlie food-directed behaviors. Cues that predict food availability powerfully regulate food-seeking behavior. Here we show that cue-evoked changes in both nucleus accumbens (NAc) dopamine (DA) and NAc cell activity are modulated by intra-cranial infusions of the stomach

  13. Neural Markers of Responsiveness to the Environment in Human Sleep

    DEFF Research Database (Denmark)

    Andrillon, Thomas; Poulsen, Andreas Trier; Hansen, Lars Kai

    2016-01-01

    Sleep is characterized by a loss of behavioral responsiveness. However, recent research has shown that the sleeping brain is not completely disconnected from its environment. How neural activity constrains the ability to process sensory information while asleep is yet unclear. Here, we instructed...... by Lempel-Ziv complexity (LZc), a measure shown to track arousal in sleep and anesthesia. Neural activity related to the semantic content of stimuli was conserved in light non-rapid eye movement (NREM) sleep. However, these processes were suppressed in deep NREM sleep and, importantly, also in REM sleep......, despite the recovery of wake-like neural activity in the latter. In NREM sleep, sensory activations were counterbalanced by evoked down states, which, when present, blocked further processing of external information. In addition, responsiveness markers correlated positively with baseline complexity, which...

  14. Analysis of electrically evoked compound action potential of the auditory nerve in children with bilateral cochlear implants.

    Science.gov (United States)

    Caldas, Fernanda Ferreira; Cardoso, Carolina Costa; Barreto, Monique Antunes de Souza Chelminski; Teixeira, Marina Santos; Hilgenberg, Anacléia Melo da Silva; Serra, Lucieny Silva Martins; Bahmad Junior, Fayez

    2016-01-01

    The cochlear implant device has the capacity to measure the electrically evoked compound action potential of the auditory nerve. The neural response telemetry is used in order to measure the electrically evoked compound action potential of the auditory nerve. To analyze the electrically evoked compound action potential, through the neural response telemetry, in children with bilateral cochlear implants. This is an analytical, prospective, longitudinal, historical cohort study. Six children, aged 1-4 years, with bilateral cochlear implant were assessed at five different intervals during their first year of cochlear implant use. There were significant differences in follow-up time (p=0.0082) and electrode position (p=0.0019) in the T-NRT measure. There was a significant difference in the interaction between time of follow-up and electrode position (p=0.0143) when measuring the N1-P1 wave amplitude between the three electrodes at each time of follow-up. The electrically evoked compound action potential measurement using neural response telemetry in children with bilateral cochlear implants during the first year of follow-up was effective in demonstrating the synchronized bilateral development of the peripheral auditory pathways in the studied population. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  15. Evoked cochlear potentials in the barn owl.

    Science.gov (United States)

    Köppl, Christine; Gleich, Otto

    2007-06-01

    Gross electrical responses to tone bursts were measured in adult barn owls, using a single-ended wire electrode placed onto the round window. Cochlear microphonic (CM) and compound action potential (CAP) responses were evaluated separately. Both potentials were physiologically vulnerable. Selective abolishment of neural responses at high frequencies confirmed that the CAP was of neural origin, while the CM remained unaffected. CAP latencies decreased with increasing stimulus frequency and CAP amplitudes were correlated with known variations in afferent fibre numbers from the different papillar regions. This suggests a local origin of the CAP along the tonotopic gradient within the basilar papilla. The audiograms derived from CAP and CM threshold responses both showed a broad frequency region of optimal sensitivity, very similar to behavioural and single-unit data, but shifted upward in absolute sensitivity. CAP thresholds rose above 8 kHz, while CM responses showed unchanged sensitivity up to 10 kHz.

  16. On Shor's Channel Extension and Constrained Channels

    Science.gov (United States)

    Holevo, A. S.; Shirokov, M. E.

    Several equivalent formulations of the additivity conjecture for constrained channels, which formally is substantially stronger than the unconstrained additivity, are given. To this end a characteristic property of the optimal ensemble for such a channel is derived, generalizing the maximal distance property. It is shown that the additivity conjecture for constrained channels holds true for certain nontrivial classes of channels. After giving an algebraic formulation for Shor's channel extension, its main asymptotic property is proved. It is then used to show that additivity for two constrained channels can be reduced to the same problem for unconstrained channels, and hence, ``global'' additivity for channels with arbitrary constraints is equivalent to additivity without constraints.

  17. G-protein coupled receptor-evoked glutamate exocytosis from astrocytes: role of prostaglandins.

    Science.gov (United States)

    Cali, Corrado; Lopatar, Jan; Petrelli, Francesco; Pucci, Luca; Bezzi, Paola

    2014-01-01

    Astrocytes are highly secretory cells, participating in rapid brain communication by releasing glutamate. Recent evidences have suggested that this process is largely mediated by Ca(2+)-dependent regulated exocytosis of VGLUT-positive vesicles. Here by taking advantage of VGLUT1-pHluorin and TIRF illumination, we characterized mechanisms of glutamate exocytosis evoked by endogenous transmitters (glutamate and ATP), which are known to stimulate Ca(2+) elevations in astrocytes. At first we characterized the VGLUT1-pHluorin expressing vesicles and found that VGLUT1-positive vesicles were a specific population of small synaptic-like microvesicles containing glutamate but which do not express VGLUT2. Endogenous mediators evoked a burst of exocytosis through activation of G-protein coupled receptors. Subsequent glutamate exocytosis was reduced by about 80% upon pharmacological blockade of the prostaglandin-forming enzyme, cyclooxygenase. On the other hand, receptor stimulation was accompanied by extracellular release of prostaglandin E2 (PGE2). Interestingly, administration of exogenous PGE2 produced per se rapid, store-dependent burst exocytosis of glutamatergic vesicles in astrocytes. Finally, when PGE2-neutralizing antibody was added to cell medium, transmitter-evoked exocytosis was again significantly reduced (by about 50%). Overall these data indicate that cyclooxygenase products are responsible for a major component of glutamate exocytosis in astrocytes and that large part of such component is sustained by autocrine/paracrine action of PGE2.

  18. G-Protein Coupled Receptor-Evoked Glutamate Exocytosis from Astrocytes: Role of Prostaglandins

    Directory of Open Access Journals (Sweden)

    Corrado Cali

    2014-01-01

    Full Text Available Astrocytes are highly secretory cells, participating in rapid brain communication by releasing glutamate. Recent evidences have suggested that this process is largely mediated by Ca2+-dependent regulated exocytosis of VGLUT-positive vesicles. Here by taking advantage of VGLUT1-pHluorin and TIRF illumination, we characterized mechanisms of glutamate exocytosis evoked by endogenous transmitters (glutamate and ATP, which are known to stimulate Ca2+ elevations in astrocytes. At first we characterized the VGLUT1-pHluorin expressing vesicles and found that VGLUT1-positive vesicles were a specific population of small synaptic-like microvesicles containing glutamate but which do not express VGLUT2. Endogenous mediators evoked a burst of exocytosis through activation of G-protein coupled receptors. Subsequent glutamate exocytosis was reduced by about 80% upon pharmacological blockade of the prostaglandin-forming enzyme, cyclooxygenase. On the other hand, receptor stimulation was accompanied by extracellular release of prostaglandin E2 (PGE2. Interestingly, administration of exogenous PGE2 produced per se rapid, store-dependent burst exocytosis of glutamatergic vesicles in astrocytes. Finally, when PGE2-neutralizing antibody was added to cell medium, transmitter-evoked exocytosis was again significantly reduced (by about 50%. Overall these data indicate that cyclooxygenase products are responsible for a major component of glutamate exocytosis in astrocytes and that large part of such component is sustained by autocrine/paracrine action of PGE2.

  19. Suboccipital craniotomy for Chiari I results in evoked potential conduction changes

    Science.gov (United States)

    Chen, Jason A.; Coutin-Churchman, Pedro E.; Nuwer, Marc R.; Lazareff, Jorge A.

    2012-01-01

    Background: Management of Chiari I is controversial, in part because there is no widely used quantitative measurement of decompression. It has been demonstrated that brainstem auditory evoked responses (BAER) and somatosensory evoked potentials (SSEP) have decreased conduction latencies after wide craniectomy. We analyzed these parameters in a suboccipital craniectomy/craniotomy procedure. Methods: Thirteen consecutive patients underwent suboccipital decompression for treatment of symptomatic Chiari I. Craniectomy was restricted to the inferior aspect of the nuchal line, and in most cases the bone flap was replaced. Neuronal conduction was monitored continuously with median nerve somatosensory evoked potentials (M-SEP), posterior tibial nerve somatosensory evoked potentials (T-SEP), BAER, or a combination. The M-SEP N20, T-SEP P37, and BAER V latencies were recorded at four milestones – preoperatively, following craniotomy, following durotomy, and following closure. Results: Five males and eight females, with average age of 9 years, were studied. Clinical improvement was noted in all 13 patients. M-SEP N20 latency decreased from a mean of 18.55 at baseline to 17.75 ms after craniotomy (P = 0.01); to 17.06 ms after durotomy (P = 0.01); and to 16.68 ms after closing (P = 0.02). T-SEP P37 latency did not change significantly. BAER V latency decreased from a mean of 6.25 ms at baseline to 6.14 ms after craniotomy (P = 0.04); to 5.98 ms after durotomy (P = 0.01); and to 5.95 ms after closing (P = 0.45). Conclusion: Significant improvements in conduction followed both craniectomy and durotomy. Bone replacement did not affect these results. PMID:23372981

  20. 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.

  1. Constrained vertebrate evolution by pleiotropic genes

    DEFF Research Database (Denmark)

    Hu, Haiyang; Uesaka, Masahiro; Guo, Song

    2017-01-01

    Despite morphological diversification of chordates over 550 million years of evolution, their shared basic anatomical pattern (or 'bodyplan') remains conserved by unknown mechanisms. The developmental hourglass model attributes this to phylum-wide conserved, constrained organogenesis stages...

  2. A Dynamic Programming Approach to Constrained Portfolios

    DEFF Research Database (Denmark)

    Kraft, Holger; Steffensen, Mogens

    2013-01-01

    This paper studies constrained portfolio problems that may involve constraints on the probability or the expected size of a shortfall of wealth or consumption. Our first contribution is that we solve the problems by dynamic programming, which is in contrast to the existing literature that applies...... the martingale method. More precisely, we construct the non-separable value function by formalizing the optimal constrained terminal wealth to be a (conjectured) contingent claim on the optimal non-constrained terminal wealth. This is relevant by itself, but also opens up the opportunity to derive new solutions...... to constrained problems. As a second contribution, we thus derive new results for non-strict constraints on the shortfall of intermediate wealth and/or consumption....

  3. Mathematical Modeling of Constrained Hamiltonian Systems

    NARCIS (Netherlands)

    Schaft, A.J. van der; Maschke, B.M.

    1995-01-01

    Network modelling of unconstrained energy conserving physical systems leads to an intrinsic generalized Hamiltonian formulation of the dynamics. Constrained energy conserving physical systems are directly modelled as implicit Hamiltonian systems with regard to a generalized Dirac structure on the

  4. Amiodarone reduces depolarization-evoked glutamate release from hippocampual synaptosomes

    Directory of Open Access Journals (Sweden)

    Chia Yu Chang

    2017-03-01

    Full Text Available Decreased brain glutamate level has emerged as a new therapeutic approach for epilepsy. This study investigated the effect and mechanism of amiodarone, an anti-arrhythmic drug with antiepileptic activity, on glutamate release in the rat hippocampus. In a synaptosomal preparation, amiodarone reduced 4-aminopyridine-evoked Ca2+-dependent glutamate release and cytosolic Ca2+ concentration elevation. Amiodarone did not affect the 4-aminopyridine-evoked depolarization of the synaptosomal membrane potential or the Na+ channel activator veratridine-evoked glutamate release, indicating that the amiodarone-mediated inhibition of glutamate release is not caused by a decrease in synaptosomal excitability. The inhibitory effect of amiodarone on 4-aminopyridine-evoked glutamate release was markedly decreased in synaptosomes pretreated with the Cav2.2 (N-type and Cav2.1 (P/Q-type channel blocker ω-conotoxin MVIIC, the calmodulin antagonists W7 and calmidazolium, or the protein kinase A inhibitors H89 and KT5720. However, the intracellular Ca2+-release inhibitors dantrolene and CGP37157 had no effect on the amiodarone-mediated inhibition of glutamate release. Furthermore, amiodarone reduced the frequency of miniature excitatory postsynaptic currents without affecting their amplitude in hippocampal slices. Our data suggest that amiodarone reduces Ca2+ influx through N- and P/Q-type Ca2+ channels, subsequently reducing the Ca2+-calmodulin/protein kinase A cascade to inhibit the evoked glutamate release from rat hippocampal nerve terminals.

  5. Glomerular input patterns in the mouse olfactory bulb evoked by retronasal odor stimuli.

    Science.gov (United States)

    Furudono, Yuichi; Cruz, Ginny; Lowe, Graeme

    2013-04-08

    Odorant stimuli can access the olfactory epithelium either orthonasally, by inhalation through the external nares, or retronasally by reverse airflow from the oral cavity. There is evidence that odors perceived through these two routes can differ in quality and intensity. We were curious whether such differences might potentially have a neural basis in the peripheral mechanisms of odor coding. To explore this possibility, we compared olfactory receptor input to glomeruli in the dorsal olfactory bulb evoked by orthonasal and retronasal stimulation. Maps of glomerular response were acquired by optical imaging of transgenic mice expressing synaptopHluorin (spH), a fluorescent reporter of presynaptic activity, in olfactory nerve terminals. We found that retronasally delivered odorants were able to activate inputs to multiple glomeruli in the dorsal olfactory bulb. The retronasal responses were smaller than orthonasal responses to odorants delivered at comparable concentrations and flow rates, and they displayed higher thresholds and right-shifted dose-response curves. Glomerular maps of orthonasal and retronasal responses were usually well overlapped, with fewer total numbers of glomeruli in retronasal maps. However, maps at threshold could be quite distinct with little overlap. Retronasal responses were also more narrowly tuned to homologous series of aliphatic odorants of varying carbon chain length, with longer chain, more hydrophobic compounds evoking little or no response at comparable vapor levels. Several features of retronasal olfaction are possibly referable to the observed properties of glomerular odorant responses. The finding that retronasal responses are weaker and sparser than orthonasal responses is consistent with psychophysical studies showing lower sensitivity for retronasal olfaction in threshold and suprathreshold tests. The similarity and overlap of orthonasal and retronasal odor maps at suprathreshold concentrations agrees with generally similar

  6. On the origin of constrained superfields

    Energy Technology Data Exchange (ETDEWEB)

    Dall’Agata, G. [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Dudas, E. [Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,F-91128 Palaiseau (France); Farakos, F. [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy)

    2016-05-06

    In this work we analyze constrained superfields in supersymmetry and supergravity. We propose a constraint that, in combination with the constrained goldstino multiplet, consistently removes any selected component from a generic superfield. We also describe its origin, providing the operators whose equations of motion lead to the decoupling of such components. We illustrate our proposal by means of various examples and show how known constraints can be reproduced by our method.

  7. Robust Tracking Control for Constrained Robots

    OpenAIRE

    Mehdi, Haifa; Boubaker, Olfa

    2014-01-01

    In this paper, a novel robust tracking control law is proposed for constrained robots under unknown stiffness environment. The stability and the robustness of the controller are proved using a Lyapunov-based approach where the relationship between the error dynamics of the robotic system and its energy is investigated. Finally, a 3DOF constrained robotic arm is used to prove the stability, the robustness and the safety of the proposed approach.

  8. Steepest-Ascent Constrained Simultaneous Perturbation for Multiobjective Optimization

    DEFF Research Database (Denmark)

    McClary, Dan; Syrotiuk, Violet; Kulahci, Murat

    2011-01-01

    The simultaneous optimization of multiple responses in a dynamic system is challenging. When a response has a known gradient, it is often easily improved along the path of steepest ascent. On the contrary, a stochastic approximation technique may be used when the gradient is unknown or costly...... that leverages information about the known gradient to constrain the perturbations used to approximate the others. We apply SP(SA)(2) to the cross-layer optimization of throughput, packet loss, and end-to-end delay in a mobile ad hoc network (MANET), a self-organizing wireless network. The results show that SP...

  9. Functional coupling constrains craniofacial diversification in Lake Tanganyika cichlids

    Science.gov (United States)

    Tsuboi, Masahito; Gonzalez-Voyer, Alejandro; Kolm, Niclas

    2015-01-01

    Functional coupling, where a single morphological trait performs multiple functions, is a universal feature of organismal design. Theory suggests that functional coupling may constrain the rate of phenotypic evolution, yet empirical tests of this hypothesis are rare. In fish, the evolutionary transition from guarding the eggs on a sandy/rocky substrate (i.e. substrate guarding) to mouthbrooding introduces a novel function to the craniofacial system and offers an ideal opportunity to test the functional coupling hypothesis. Using a combination of geometric morphometrics and a recently developed phylogenetic comparative method, we found that head morphology evolution was 43% faster in substrate guarding species than in mouthbrooding species. Furthermore, for species in which females were solely responsible for mouthbrooding the males had a higher rate of head morphology evolution than in those with bi-parental mouthbrooding. Our results support the hypothesis that adaptations resulting in functional coupling constrain phenotypic evolution. PMID:25948565

  10. Cortical Response of Retardates for AER Audiometry

    Science.gov (United States)

    Hogan, Donald D.

    1971-01-01

    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. Analytical approaches to estimation of temporal frequency preference from visual evoked potentials

    Science.gov (United States)

    Wierzbicka, Agnieszka; Kordecka, Katarzyna; Żygierewicz, Jarosław; Waleszczyk, Wioletta

    2017-08-01

    There are various ways to study neuronal processing of information about temporal frequency content of visual stimuli. The two most fundamental methods are 1) direct measurement of response amplitude, e.g. an amplitude of averaged visual evoked potential, and 2) assessment of response magnitude after transformation of electrophysiological signal from time to frequency domain. In our study we found it impossible to use the same paradigm to analyze the whole spectrum of temporal frequencies in local field potentials recorded during visual electrophysiology experiments performed on anesthetized rats. Visual responses were recorded from all layers of primary visual cortex in response to flashing light with temporal frequency in the range of 0.5 - 15 Hz. We found that for frequencies lower than 2 Hz it is difficult to draw conclusions based on power spectrum alone, while for high frequencies (> 2 Hz) the evoked potential in time domain could not be observed. We discuss possible physiological reasons of these difficulties and the advantages of the Welch method instead of the periodogram to analyze signals in the frequency domain.

  12. The Perception of Dynamic and Static Facial Expressions of Happiness and Disgust Investigated by ERPs and fMRI Constrained Source Analysis

    Science.gov (United States)

    Trautmann-Lengsfeld, Sina Alexa; Domínguez-Borràs, Judith; Escera, Carles; Herrmann, Manfred; Fehr, Thorsten

    2013-01-01

    A recent functional magnetic resonance imaging (fMRI) study by our group demonstrated that dynamic emotional faces are more accurately recognized and evoked more widespread patterns of hemodynamic brain responses than static emotional faces. Based on this experimental design, the present study aimed at investigating the spatio-temporal processing of static and dynamic emotional facial expressions in 19 healthy women by means of multi-channel electroencephalography (EEG), event-related potentials (ERP) and fMRI-constrained regional source analyses. ERP analysis showed an increased amplitude of the LPP (late posterior positivity) over centro-parietal regions for static facial expressions of disgust compared to neutral faces. In addition, the LPP was more widespread and temporally prolonged for dynamic compared to static faces of disgust and happiness. fMRI constrained source analysis on static emotional face stimuli indicated the spatio-temporal modulation of predominantly posterior regional brain activation related to the visual processing stream for both emotional valences when compared to the neutral condition in the fusiform gyrus. The spatio-temporal processing of dynamic stimuli yielded enhanced source activity for emotional compared to neutral conditions in temporal (e.g., fusiform gyrus), and frontal regions (e.g., ventromedial prefrontal cortex, medial and inferior frontal cortex) in early and again in later time windows. The present data support the view that dynamic facial displays trigger more information reflected in complex neural networks, in particular because of their changing features potentially triggering sustained activation related to a continuing evaluation of those faces. A combined fMRI and EEG approach thus provides an advanced insight to the spatio-temporal characteristics of emotional face processing, by also revealing additional neural generators, not identifiable by the only use of an fMRI approach. PMID:23818974

  13. Optical and electrical recording of neural activity evoked by graded contrast visual stimulus

    Directory of Open Access Journals (Sweden)

    Bulf Luca

    2007-07-01

    Full Text Available Abstract Background Brain activity has been investigated by several methods with different principles, notably optical ones. Each method may offer information on distinct physiological or pathological aspects of brain function. The ideal instrument to measure brain activity should include complementary techniques and integrate the resultant information. As a "low cost" approach towards this objective, we combined the well-grounded electroencephalography technique with the newer near infrared spectroscopy methods to investigate human visual function. Methods The article describes an embedded instrumentation combining a continuous-wave near-infrared spectroscopy system and an electroencephalography system to simultaneously monitor functional hemodynamics and electrical activity. Near infrared spectroscopy (NIRS signal depends on the light absorption spectra of haemoglobin and measures the blood volume and blood oxygenation regulation supporting the neural activity. The NIRS and visual evoked potential (VEP are concurrently acquired during steady state visual stimulation, at 8 Hz, with a b/w "windmill" pattern, in nine human subjects. The pattern contrast is varied (1%, 10%, 100% according to a stimulation protocol. Results In this study, we present the measuring system; the results consist in concurrent recordings of hemodynamic changes and evoked potential responses emerging from different contrast levels of a patterned stimulus. The concentration of [HbO2] increases and [HHb] decreases after the onset of the stimulus. Their variation shows a clear relationship with the contrast value: large contrast produce huge difference in concentration, while low contrast provokes small concentration difference. This behaviour is similar to the already known relationship between VEP response amplitude and contrast. Conclusion The simultaneous recording and analysis of NIRS and VEP signals in humans during visual stimulation with a b/w pattern at variable

  14. Carbon-constrained health care enterprise.

    Science.gov (United States)

    Gell, Michael

    2010-02-01

    The health economy is a significant part of a national economy accounting typically for about 8% of GDP spent. As national economies respond to the dual challenges of severe economic turbulence on the global scale and climate change mitigation, the health economy is coming under increasing pressure to respond. Indications for sharp reductions in budgets and reductions in greenhouse gas emissions, such as carbon dioxide, are widespread. In this paper an analysis is undertaken of the diverse forces acting on a typical health care enterprise. The forces, both economic and carbon related, are investigated in terms of their effects through the enterprise and across its boundaries on the supply, demand and waste sides. The overall aim is to show how the enterprise and whole supply chains may flip synchronously into a low-carbon evolutionary pathway. By illustrating how different elements of the health care enterprise may respond to these developments, diverse opportunities for cost reduction, carbon reduction and product (goods and services) development are identified. These opportunities involve a variety of waste reduction and energy and materials conservation measures as well as new ways of collaborating with other enterprises going through similar transformations. The overall objective is to show that the carbon-constrained health care enterprise and the low-carbon health economy in which it sits may broaden its role in the coming decades to include a degree of responsibility for the health of the environment. This broader role is likely to supplement and entangle with the traditional role of the health economy, currently focused narrowly on human health, and lead to extensive organisational transformation, and infrastructure and product developments.

  15. HLA-DM constrains epitope selection in the human CD4 T cell response to vaccinia virus by favoring the presentation of peptides with longer HLA-DM-mediated half-lives1

    Science.gov (United States)

    Yin, Liusong; Calvo-Calle, J. Mauricio; Dominguez-Amorocho, Omar; Stern, Lawrence J.

    2012-01-01

    HLA-DM (DM) is a non-classical major histocompatibility complex II (MHC II) protein that acts as a peptide editor to mediate the exchange of peptides loaded onto MHC II during antigen presentation. Although the ability of DM to promote peptide exchange in vitro and in vivo is well established, the role of DM in epitope selection is still unclear, especially in human response to infectious disease. In this study, we addressed this question in the context of the human CD4 T cell response to vaccinia virus. We measured the IC50, intrinsic dissociation half-life, and DM-mediated dissociation half-life for a large set of peptides derived from the major core protein A10L and other known vaccinia epitopes bound to HLA-DR1, and compared these properties to the presence and magnitude of peptide-specific CD4+ T cell responses. We found that MHC II-peptide complex kinetic stability in the presence of DM distinguishes T cell epitopes from non-recognized peptides in A10L peptides and also in a set of predicted tight binders from the entire vaccinia genome. Taken together, these analyses demonstrate that DM-mediated dissociation half-life is a strong and independent factor governing peptide immunogenicity by favoring the presentation of peptides with greater kinetic stability in the presence of DM. PMID:22966084

  16. HLA-DM constrains epitope selection in the human CD4 T cell response to vaccinia virus by favoring the presentation of peptides with longer HLA-DM-mediated half-lives.

    Science.gov (United States)

    Yin, Liusong; Calvo-Calle, J Mauricio; Dominguez-Amorocho, Omar; Stern, Lawrence J

    2012-10-15

    HLA-DM (DM) is a nonclassical MHC class II (MHC II) protein that acts as a peptide editor to mediate the exchange of peptides loaded onto MHC II during Ag presentation. Although the ability of DM to promote peptide exchange in vitro and in vivo is well established, the role of DM in epitope selection is still unclear, especially in human response to infectious disease. In this study, we addressed this question in the context of the human CD4 T cell response to vaccinia virus. We measured the IC(50), intrinsic dissociation t(1/2), and DM-mediated dissociation t(1/2) for a large set of peptides derived from the major core protein A10L and other known vaccinia epitopes bound to HLA-DR1 and compared these properties to the presence and magnitude of peptide-specific CD4(+) T cell responses. We found that MHC II-peptide complex kinetic stability in the presence of DM distinguishes T cell epitopes from nonrecognized peptides in A10L peptides and also in a set of predicted tight binders from the entire vaccinia genome. Taken together, these analyses demonstrate that DM-mediated dissociation t(1/2) is a strong and independent factor governing peptide immunogenicity by favoring the presentation of peptides with greater kinetic stability in the presence of DM.

  17. Brain evoked potential use in a physical medicine and rehabilitation setting.

    Science.gov (United States)

    Rappaport, M; Hopkins, K; Hall, K; Belleza, T; Berrol, S

    1978-01-01

    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.

  18. Assessment of an ICA-based noise reduction method for multi-channel auditory evoked potentials

    Science.gov (United States)

    Mirahmadizoghi, Siavash; Bell, Steven; Simpson, David

    2015-03-01

    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.

  19. Contact heat evoked potentials using simultaneous EEG and fMRI and their correlation with evoked pain

    Directory of Open Access Journals (Sweden)

    Atherton Duncan

    2008-12-01

    Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS utilises rapidly delivered heat pulses with adjustable peak temperatures to stimulate the differential warm/heat thresholds of receptors expressed by Aδ and C fibres. The resulting evoked potentials can be recorded and measured, providing a useful clinical tool for the study of thermal and nociceptive pathways. Concurrent recording of contact heat evoked potentials using electroencephalogram (EEG and functional magnetic resonance imaging (fMRI has not previously been reported with CHEPS. Developing simultaneous EEG and fMRI with CHEPS is highly desirable, as it provides an opportunity to exploit the high temporal resolution of EEG and the high spatial resolution of fMRI to study the reaction of the human brain to thermal and nociceptive stimuli. Methods In this study we have recorded evoked potentials stimulated by 51°C contact heat pulses from CHEPS using EEG, under normal conditions (baseline, and during continuous and simultaneous acquisition of fMRI images in ten healthy volunteers, during two sessions. The pain evoked by CHEPS was recorded on a Visual Analogue Scale (VAS. Results Analysis of EEG data revealed that the latencies and amplitudes of evoked potentials recorded during continuous fMRI did not differ significantly from baseline recordings. fMRI results were consistent with previous thermal pain studies, and showed Blood Oxygen Level Dependent (BOLD changes in the insula, post-central gyrus, supplementary motor area (SMA, middle cingulate cortex and pre-central gyrus. There was a significant positive correlation between the evoked potential amplitude (EEG and the psychophysical perception of pain on the VAS. Conclusion The results of this study demonstrate the feasibility of recording contact heat evoked potentials with EEG during continuous and simultaneous fMRI. The combined use of the two methods can lead to identification of distinct patterns of brain

  20. 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 stimulation. These predicted responses are proven to be well-suited as templates for a BBVEP-based BCI, thereby enabling communication and control by brain activity only.

  1. Comparisons of transient evoked otoacoustic emissions using chirp and click stimuli.

    Science.gov (United States)

    Keefe, Douglas H; Feeney, M Patrick; Hunter, Lisa L; Fitzpatrick, Denis F

    2016-09-01

    Transient-evoked otoacoustic emission (TEOAE) responses (0.7-8 kHz) were measured in normal-hearing adult ears using click stimuli and chirps whose local frequency increased or decreased linearly with time over the stimulus duration. Chirp stimuli were created by allpass filtering a click with relatively constant incident pressure level over frequency. Chirp TEOAEs were analyzed as a nonlinear residual signal by inverse allpass filtering each chirp response into an equivalent click response. Multi-window spectral and temporal averaging reduced noise levels compared to a single-window average. Mean TEOAE levels using click and chirp stimuli were similar with respect to their standard errors in adult ears. TEOAE group delay, group spread, instantaneous frequency, and instantaneous bandwidth were similar overall for chirp and click conditions, except for small differences showing nonlinear interactions differing across stimulus conditions. These results support the theory of a similar generation mechanism on the basilar membrane for both click and chirp conditions based on coherent reflection within the tonotopic region. TEOAE temporal fine structure was invariant across changes in stimulus level, which is analogous to the intensity invariance of click-evoked basilar-membrane displacement data.

  2. Objective detection of auditory steady-state evoked potentials based on mutual information.

    Science.gov (United States)

    Bidelman, Gavin M; Bhagat, Shaum P

    2016-01-01

    Recently, we developed a metric to objectively detect human auditory evoked potentials based on the mutual information (MI) between neural responses and stimulus spectrograms. Here, the MI algorithm is evaluated further for validity in testing the auditory steady-state response (ASSR), a sustained potential used in objective audiometry. MI was computed between spectrograms of ASSRs and their evoking stimuli to quantify the shared time-frequency information between neuroelectric activity and stimulus acoustics. MI was compared against two traditional ASSR detection metrics: F-test and magnitude-squared coherence (MSC). Using an empirically derived threshold (⊖MI=1.45), MI was applied as a binary classifier to distinguish actual biological responses recorded in human participants (n=11) from sham recordings, containing only EEG noise (i.e., non-stimulus-control condition). MI achieved high overall accuracy (>90%) in identifying true ASSRs from sham recordings, with true positive/true negative rates of 82/100%. During online averaging, comparison with two other indices (F-test, MSC) indicated that MI could detect ASSRs in roughly half the number of trials (i.e., ∼400 sweeps) as the MSC and performed comparably to the F-test, but showed slightly better signal detection performance. MI provides an alternative, more flexible metric for efficient and automated ASSR detection.

  3. Comparisons of transient evoked otoacoustic emissions using chirp and click stimuli

    Science.gov (United States)

    Keefe, Douglas H.; Feeney, M. Patrick; Hunter, Lisa L.; Fitzpatrick, Denis F.

    2016-01-01

    Transient-evoked otoacoustic emission (TEOAE) responses (0.7–8 kHz) were measured in normal-hearing adult ears using click stimuli and chirps whose local frequency increased or decreased linearly with time over the stimulus duration. Chirp stimuli were created by allpass filtering a click with relatively constant incident pressure level over frequency. Chirp TEOAEs were analyzed as a nonlinear residual signal by inverse allpass filtering each chirp response into an equivalent click response. Multi-window spectral and temporal averaging reduced noise levels compared to a single-window average. Mean TEOAE levels using click and chirp stimuli were similar with respect to their standard errors in adult ears. TEOAE group delay, group spread, instantaneous frequency, and instantaneous bandwidth were similar overall for chirp and click conditions, except for small differences showing nonlinear interactions differing across stimulus conditions. These results support the theory of a similar generation mechanism on the basilar membrane for both click and chirp conditions based on coherent reflection within the tonotopic region. TEOAE temporal fine structure was invariant across changes in stimulus level, which is analogous to the intensity invariance of click-evoked basilar-membrane displacement data. PMID:27914441

  4. Conditioning stimulus can influence an external urethral sphincter contraction evoked by a magnetic stimulation.

    Science.gov (United States)

    Wefer, Bjoern; Reitz, André; Knapp, Peter A; Bannowsky, Andreas; Juenemann, Klaus-Peter; Schurch, Brigitte

    2005-01-01

    To study the effect of a conditioning stimulus on an external urethral sphincter (EUS)contraction evoked by a magnetic stimulation at different time intervals. Seven healthy male volunteers underwent EUS pressure measurement. At baseline, magnetic stimulation of the lumbosacral spinal cord above the motor threshold was performed and evoked EUS pressure responses were recorded. The lumbosacral magnetic stimulation was repeated with same intensity, while a selective electrical dorsal penile nerve stimulation below the bulbocavernosus reflex (BCR) threshold was preceding at five different intervals (10, 20, 30, 50, 100 msec). The protocol was performed with empty and full bladder (BLA), and baseline responses were statistically compared to those with combined stimulation. When the dorsal penile nerve electrical stimulation preceded the lumbosacral magnetic stimulation by 20 msec (P=0.0048), 50 msec (P=0.0039), or 100 msec (P=0.0002), the amplitudes of the EUS pressure response with empty BLA were significantly reduced compared to lumbosacral magnetic stimulation alone. With a filled BLA, the amplitudes of the EUS were significantly reduced only at an interval of 50 msec (Pstimulation seems to have the capacity to inhibit the external urethral sphincter contraction induced by a magnetic stimulation. The inhibitory effect seems to depend on the latency between the peripheral and lumbosacral stimulation as well as on the degree of BLA filling. It remains to be proved if the neuromodulative effect of the conditional stimulus occurs at a spinal or supraspinal level. Copyright (c) 2005 Wiley-Liss, Inc.

  5. Weighted Constrained Hue-Plane Preserving Camera Characterization.

    Science.gov (United States)

    Find Andersen, Casper; Connah, David

    2016-07-11

    Color correction relates device dependent sensor responses (RGB) to device independent color values (XYZ). Here we present a new approach to Hue-plane Preserving Color Correction (HPPCC) using weighted constrained 3 × 3 matrices. Hue-plane preservation was introduced in [1] in conjunction with an HPPCC method. That method maps using a finite number of local white point preserving 3 × 3 matrices, each of which operates in a hue-angle delimited subregion of device space defined by the white and two adjacent chromatic training set colors. However, that formulation does not leave room for optimization or continuity beyond C0 in the transitions between the subregions. To remedy that our new method uses hue-angle specific weighted matrixing: given a device RGB from which a device hue-angle is derived, a corresponding transformation matrix is found as the normalized weighted sum of all precalculated constrained white point and training color preserving matrices. Each weight is calculated as a power function of the minimum difference between the device and the training color hue-angle. The weighting function provides local influence to the matrices that are in close hue-angle proximity to the device color. The power of the function is optimized for global accuracy. We call this Hue-plane Preserving Color Correction by Weighted Constrained Matrixing HPPCC-WCM 1 1. Experiments performed using different input spectra show that our method consistently improves on both stability and accuracy compared to state of the art methods.

  6. The role of Magnetic Resonance Imaging and Visual Evoked ...

    African Journals Online (AJOL)

    Introduction: To report our experience in management of patients with optic neuritis. The effects of brain magnetic resonance imaging and visual evoked potential on management were investigated. Methods: This is a four years clinical trial that included patients presenting with first attack of optic neuritis older than 16 years ...

  7. Visual evoked potentials in workers with chronic solvent encephalopathy

    NARCIS (Netherlands)

    Verberk, Maarten M.; Brons, Joke T.; Sallé, Herman J. A.

    2004-01-01

    Objectives. Two promising variations of visual evoked potentials (VEPs) were studied in solvent-exposed workers: the effect of a low-contrast stimulus in comparison with the usually applied high contrast, and the ability of pattern-onset VEP to reveal damage to specific visual cortical areas. In

  8. The computation of evoked heart rate and blood pressure

    NARCIS (Netherlands)

    Koers, G.; Mulder, L.J.M.; van der Veen, F.M.

    1999-01-01

    For many years psychophysiologists have been interested in stimulus related changes in heart rate and blood pressure. To represent these evoked heart rate and blood pressure patterns, heart rate and blood pressure data have to be transformed into equidistant time series. This paper presents an

  9. The masseteric reflex evoked by tooth and denture tapping.

    Science.gov (United States)

    Brodin, P; Fløystrand, F; Orstavik, J

    1991-07-01

    The characteristics of the masseter reflex evoked by tapping a maxillary incisor were compared with the reflex pattern evoked by tapping a corresponding denture tooth after insertion of an immediate denture. Up to three inhibitory phases (I-1, I-2 and I-3), followed by excitation, were found on an averaged EMG. The tapping force threshold for the early inhibitory phase was lower than for the late phases. The pattern of the reflex was generally the same before and after insertion of the denture, but the threshold values increased. After insertion of the denture, the threshold for I-1 increased from 1 +/- 0.3N to 2.2 +/- 0.4N, the threshold for I-2 increased from 2.4 +/- 0.8N to 3.8 +/- 0.9N, and the threshold for I-3 increased from 5.1 +/- 0.6N to 8.3 +/- 0.9N. The latency period for I-1 also increased from 12.3 +/- 0.5 ms to 13.1 +/- 0.3 ms after insertion of the denture. After relining, the threshold for evoking I-1 decreased from 2.7 +/- 1.2N to 1.2 +/- 0.6N. It was assumed that the mechanoreceptors situated in the mucosa under the denture base could take over the functional role of the periodontal mechanoreceptors for evoking the masseter reflex during tapping, and that these afferents probably had connections to the same interneurones.

  10. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  11. Continuation of Sets of Constrained Orbit Segments

    DEFF Research Database (Denmark)

    Schilder, Frank; Brøns, Morten; Chamoun, George Chaouki

    Sets of constrained orbit segments of time continuous flows are collections of trajectories that represent a whole or parts of an invariant set. A non-trivial but simple example is a homoclinic orbit. A typical representation of this set consists of an equilibrium point of the flow and a trajectory...... that starts close and returns close to this fixed point within finite time. More complicated examples are hybrid periodic orbits of piecewise smooth systems or quasi-periodic invariant tori. Even though it is possible to define generalised two-point boundary value problems for computing sets of constrained...... orbit segments, this is very disadvantageous in practice. In this talk we will present an algorithm that allows the efficient continuation of sets of constrained orbit segments together with the solution of the full variational problem....

  12. Characterisation and mechanisms of bradykinin-evoked pain in man using iontophoresis.

    Science.gov (United States)

    Paterson, Kathryn J; Zambreanu, Laura; Bennett, David L H; McMahon, Stephen B

    2013-06-01

    Bradykinin (BK) is an inflammatory mediator that can evoke oedema and vasodilatation, and is a potent algogen signalling via the B1 and B2 G-protein coupled receptors. In naïve skin, BK is effective via constitutively expressed B2 receptors (B2R), while B1 receptors (B1R) are purported to be upregulated by inflammation. The aim of this investigation was to optimise BK delivery to investigate the algesic effects of BK and how these are modulated by inflammation. BK iontophoresis evoked dose- and temperature-dependent pain and neurogenic erythema, as well as thermal and mechanical hyperalgesia (P skin was pretreated with compound 4880 to degranulate the MCs prior to BK challenge. The early phase of BK-evoked pain was reduced in degranulated skin (P wheal, and flare were still evident. In contrast to BK, the B1R selective agonist des-Arg9-BK failed to induce pain or sensitise naïve skin. However, following skin inflammation induced by ultraviolet B irradiation, this compound produced a robust pain response. We have optimised a versatile experimental model by which BK and its analogues can be administered to human skin. We have found that there is an early phase of BK-induced pain which partly depends on the release of inflammatory mediators by MCs; however, subsequent hyperalgesia is not dependent on MC degranulation. In naïve skin, B2R signaling predominates, however, cutaneous inflammation results in enhanced B1R responses. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  13. Polysulfide evokes acute pain through the activation of nociceptive TRPA1 in mouse sensory neurons.

    Science.gov (United States)

    Hatakeyama, Yukari; Takahashi, Kenji; Tominaga, Makoto; Kimura, Hideo; Ohta, Toshio

    2015-05-02

    Hydrogen sulfide (H2S) is oxidized to polysulfide. Recent reports show that this sulfur compound modulates various biological functions. We have reported that H2S is involved in inflammatory pain in mice. On the other hand, little is known about the functional role of polysulfide in sensory neurons. Here we show that polysulfide selectively stimulates nociceptive TRPA1 and evokes acute pain, using TRPA1-gene deficient mice (TRPA1(-/-)), a heterologous expression system and a TRPA1-expressing cell line. In wild-type mouse sensory neurons, polysulfide elevated the intracellular Ca concentration ([Ca(2+)]i) in a dose-dependent manner. The half maximal effective concentration (EC50) of polysulfide was less than one-tenth that of H2S. The [Ca(2+)]i responses to polysulfide were observed in neurons responsive to TRPA1 agonist and were inhibited by blockers of TRPA1 but not of TRPV1. Polysulfide failed to evoke [Ca(2+)]i increases in neurons from TRPA1(-/-) mice. In RIN-14B cells, constitutively expressing rat TRPA1, polysulfide evoked [Ca(2+)]i increases with the same EC50 value as in sensory neurons. Heterologously expressed mouse TRPA1 was activated by polysulfide and that was suppressed by dithiothreitol. Analyses of the TRPA1 mutant channel revealed that cysteine residues located in the internal domain were related to the sensitivity to polysulfide. Intraplantar injection of polysulfide into the mouse hind paw induced acute pain and edema which were significantly less than in TRPA1(-/-) mice. The present data suggest that polysulfide functions as pronociceptive substance through the activation of TRPA1 in sensory neurons. Since the potency of polysulfide is higher than parental H2S and this sulfur compound is generated under pathophysiological conditions, it is suggested that polysulfide acts as endogenous ligand for TRPA1. Therefore, TRPA1 may be a promising therapeutic target for endogenous sulfur compound-related algesic action.

  14. On Why Targets Evoke P3 Components in Prediction Tasks: Drawing an Analogy between Prediction and Matching Tasks

    Directory of Open Access Journals (Sweden)

    Rolf Verleger

    2017-10-01

    Full Text Available P3 is the most conspicuous component in recordings of stimulus-evoked EEG potentials from the human scalp, occurring whenever some task has to be performed with the stimuli. The process underlying P3 has been assumed to be the updating of expectancies. More recently, P3 has been related to decision processing and to activation of established stimulus-response associations (S/R-link hypothesis. However, so far this latter approach has not provided a conception about how to explain the occurrence of P3 with predicted stimuli, although P3 was originally discovered in a prediction task. The present article proposes such a conception. We assume that the internal responses right or wrong both become associatively linked to each predicted target and that one of these two response alternatives gets activated as a function of match or mismatch of the target to the preceding prediction. This seems similar to comparison tasks where responses depend on the matching of the target stimulus with a preceding first stimulus (S1. Based on this idea, this study compared the effects of frequencies of first events (predictions or S1 on target-evoked P3s in prediction and comparison tasks. Indeed, frequencies not only of targets but also of first events had similar effects across tasks on target-evoked P3s. These results support the notion that P3 evoked by predicted stimuli reflects activation of appropriate internal “match” or “mismatch” responses, which is compatible with S/R-link hypothesis.

  15. Amiodarone reduces depolarization-evoked glutamate release from hippocampual synaptosomes.

    Science.gov (United States)

    Chang, Chia Yu; Hung, Chi Feng; Huang, Shu Kuei; Kuo, Jinn Rung; Wang, Su Jane

    2017-03-01

    Decreased brain glutamate level has emerged as a new therapeutic approach for epilepsy. This study investigated the effect and mechanism of amiodarone, an anti-arrhythmic drug with antiepileptic activity, on glutamate release in the rat hippocampus. In a synaptosomal preparation, amiodarone reduced 4-aminopyridine-evoked Ca2+-dependent glutamate release and cytosolic Ca2+ concentration elevation. Amiodarone did not affect the 4-aminopyridine-evoked depolarization of the synaptosomal membrane potential or the Na+ channel activator veratridine-evoked glutamate release, indicating that the amiodarone-mediated inhibition of glutamate release is not caused by a decrease in synaptosomal excitability. The inhibitory effect of amiodarone on 4-aminopyridine-evoked glutamate release was markedly decreased in synaptosomes pretreated with the Cav2.2 (N-type) and Cav2.1 (P/Q-type) channel blocker ω-conotoxin MVIIC, the calmodulin antagonists W7 and calmidazolium, or the protein kinase A inhibitors H89 and KT5720. However, the intracellular Ca2+-release inhibitors dantrolene and CGP37157 had no effect on the amiodarone-mediated inhibition of glutamate release. Furthermore, amiodarone reduced the frequency of miniature excitatory postsynaptic currents without affecting their amplitude in hippocampal slices. Our data suggest that amiodarone reduces Ca2+ influx through N- and P/Q-type Ca2+ channels, subsequently reducing the Ca2+-calmodulin/protein kinase A cascade to inhibit the evoked glutamate release from rat hippocampal nerve terminals. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  16. Modeling auditory evoked potentials to complex stimuli

    DEFF Research Database (Denmark)

    Rønne, Filip Munch

    cochlear compression would be of great benefit, as a more precise diagnose of the deficits underlying a potential hearing impairment in both infants and adults could be obtained. It was demonstrated in this thesis, via experimental recordings and supported by model simulations, that the growth of the ASSR....... Sensorineural hearing impairments is commonly associated with a loss of outer hair-cell functionality, and a measurable consequence is the decreased amount of cochlear compression at frequencies corresponding to the damaged locations in the cochlea. In clinical diagnostics, a fast and objective measure of local...... 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...

  17. Characterizing constraining forces in the alignment phase of orthodontic treatment.

    Science.gov (United States)

    Gibson, Christopher G; Lin, Feng-Chang; Phillips, Ceib; Edelman, Alex; Ko, Ching-Chang

    2018-01-01

    To describe the frictional forces (FF) that constrain wire sliding in the initial alignment phase of treatment using a new term, the "constraining force" (CF), and to hypothesize that CF is dependent on two factors: the hyperelastic behavior of archwires and the specific type of tooth geometric malalignment present. A laboratory device that simulates the four distinct malalignment types (in-out, rotation, tipping, and vertical step) was used to couple with an Instron testing apparatus. Incremental CF data for the four types of malalignment were recorded. Each type had five trials per increment of severity, from which the CF was averaged using 0.016-inch copper-nickel-titanium (CuNiTi) archwires. Two types of friction curves were obtained: a traditional step function response and a power regression response. For all malalignment types, increasing degrees of irregularity increased power regression responses and CF. A severity turning point, displayed as a sudden increase in CF, occurred for each malalignment. The rotation type of malalignment yielded the lowest CF, while the vertical step type resulted in the highest CF. The data infer a hypothesis that malrotation type having weak CF might act as a limiting factor in the alignment phase to unravel the neighboring teeth. Future investigations to compare clinical and bench data can help explain more fully the constraints impeding alignment resolution and the factors governing the ability to bring malaligned teeth into alignment.

  18. Waveform Similarity Analysis: A Simple Template Comparing Approach for Detecting and Quantifying Noisy Evoked Compound Action Potentials.

    Directory of Open Access Journals (Sweden)

    Jason Robert Potas

    Full Text Available Experimental electrophysiological assessment of evoked responses from regenerating nerves is challenging due to the typical complex response of events dispersed over various latencies and poor signal-to-noise ratio. Our objective was to automate the detection of compound action potential events and derive their latencies and magnitudes using a simple cross-correlation template comparison approach. For this, we developed an algorithm called Waveform Similarity Analysis. To test the algorithm, challenging signals were generated in vivo by stimulating sural and sciatic nerves, whilst recording evoked potentials at the sciatic nerve and tibialis anterior muscle, respectively, in animals recovering from sciatic nerve transection. Our template for the algorithm was generated based on responses evoked from the intact side. We also simulated noisy signals and examined the output of the Waveform Similarity Analysis algorithm with imperfect templates. Signals were detected and quantified using Waveform Similarity Analysis, which was compared to event detection, latency and magnitude measurements of the same signals performed by a trained observer, a process we called Trained Eye Analysis. The Waveform Similarity Analysis algorithm could successfully detect and quantify simple or complex responses from nerve and muscle compound action potentials of intact or regenerated nerves. Incorrectly specifying the template outperformed Trained Eye Analysis for predicting signal amplitude, but produced consistent latency errors for the simulated signals examined. Compared to the trained eye, Waveform Similarity Analysis is automatic, objective, does not rely on the observer to identify and/or measure peaks, and can detect small clustered events even when signal-to-noise ratio is poor. Waveform Similarity Analysis provides a simple, reliable and convenient approach to quantify latencies and magnitudes of complex waveforms and therefore serves as a useful tool for

  19. The effectiveness of FES-evoked EMG potentials to assess muscle force and fatigue in individuals with spinal cord injury.

    Science.gov (United States)

    Ibitoye, Morufu Olusola; Estigoni, Eduardo H; Hamzaid, Nur Azah; Wahab, Ahmad Khairi Abdul; Davis, Glen M

    2014-07-14

    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 force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI) population.

  20. The Effectiveness of FES-Evoked EMG Potentials to Assess Muscle Force and Fatigue in Individuals with Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Morufu Olusola Ibitoye

    2014-07-01

    Full Text Available 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 < 0.05 between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI population.

  1. The effects of rise/fall time and plateau time on ocular vestibular evoked myogenic potentials.

    Science.gov (United States)

    Kantner, Claudia; Hapfelmeier, Alexander; Drexl, Markus; Gürkov, Robert

    2014-09-01

    Ocular vestibular evoked myogenic potentials (oVEMP) are strongly influenced by recording conditions and stimulus parameters. Throughout the published literature, a large variety of stimuli is used for eliciting oVEMP. Our objective was to determine the effects of different rise/fall times and plateau times on oVEMP amplitudes and latencies. 32 healthy subjects were enrolled in the study. 500 Hz air-conducted tone bursts with the parameters rise-plateau-fall time 0-4-0, 4-0-4, 2-2-2 and 2-4-2 ms were used for eliciting oVEMP. For all stimuli, response prevalences were 100 %. The 4-0-4 ms stimulus generated the smallest amplitudes, whereas the 2-2-2 and 0-4-0 ms stimuli achieved the largest amplitudes. n1 and p1 latencies were significantly shorter for the 0-4-0 ms than for the other stimuli, whereas latencies in response to the 4-0-4 ms stimulus were prolonged. Hence, a variety of stimuli is suitable for evoking oVEMP in healthy subjects. We recommend a 2-2-2 ms stimulus for clinical testing of oVEMP elicited by air conducted sound, because it reproducibly generates oVEMP without exposing the ear to unnecessary amounts of acoustic energy.

  2. Neutron Powder Diffraction and Constrained Refinement

    DEFF Research Database (Denmark)

    Pawley, G. S.; Mackenzie, Gordon A.; Dietrich, O. W.

    1977-01-01

    The first use of a new program, EDINP, is reported. This program allows the constrained refinement of molecules in a crystal structure with neutron diffraction powder data. The structures of p-C6F4Br2 and p-C6F4I2 are determined by packing considerations and then refined with EDINP. Refinement...

  3. Semantic Web in a Constrained Environment

    NARCIS (Netherlands)

    Rietveld, L.J.; Schlobach, K.S.

    2012-01-01

    The semantic web is intrinsically constrained by its environment. These constraints act as a bottlenecks and limit the performance of applications in various ways. Examples of such constraints are the limited availability of memory, disk space, or a limited network bandwidth. But how do these bounds

  4. Constrained superfields from inflation to reheating

    Directory of Open Access Journals (Sweden)

    Ioannis Dalianis

    2017-10-01

    Full Text Available We construct effective supergravity theories from customized constrained superfields which provide a setup consistent both for the description of inflation and the subsequent reheating processes. These theories contain the minimum degrees of freedom in the bosonic sector required for single-field inflation.

  5. Constrained Optimization in Simulation : A Novel Approach

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; van Beers, W.C.M.; van Nieuwenhuyse, I.

    2008-01-01

    This paper presents a novel heuristic for constrained optimization of random computer simulation models, in which one of the simulation outputs is selected as the objective to be minimized while the other outputs need to satisfy prespeci¯ed target values. Besides the simulation outputs, the

  6. Integrating job scheduling and constrained network routing

    DEFF Research Database (Denmark)

    Gamst, Mette

    2010-01-01

    This paper examines the NP-hard problem of scheduling jobs on resources such that the overall profit of executed jobs is maximized. Job demand must be sent through a constrained network to the resource before execution can begin. The problem has application in grid computing, where a number...

  7. A model for optimal constrained adaptive testing

    NARCIS (Netherlands)

    van der Linden, Willem J.; Reese, Lynda M.

    2001-01-01

    A model for constrained computerized adaptive testing is proposed in which the information on the test at the ability estimate is maximized subject to a large variety of possible constraints on the contents of the test. At each item-selection step, a full test is first assembled to have maximum

  8. Constrained Registration of the Wrist Joint

    NARCIS (Netherlands)

    Van de Giessen, M.; Streekstra, G.J.; Strackee, S.D.; Maas, M.; Grimbergen, K.A.; Van Vliet, L.J.; Vos, F.M.

    2009-01-01

    Comparing wrist shapes of different individuals requires alignment of these wrists into the same pose. Unconstrained registration of the carpal bones results in anatomically nonfeasible wrists. In this paper, we propose to constrain the registration using the shapes of adjacent bones, by keeping the

  9. Constrained registration of the wrist joint

    NARCIS (Netherlands)

    van de Giessen, M.; Streekstra, G.J.; Strackee, S.D.; Maas, M.; Grimbergen, K.A.; van Vliet, L.J.; Vos, F.M.

    2009-01-01

    Comparing wrist shapes of different individuals requires alignment of these wrists into the same pose. Unconstrained registration of the carpal bones results in anatomically nonfeasible wrists. In this paper, we propose to constrain the registration using the shapes of adjacent bones, by keeping the

  10. Factors Constraining Farmers Use of Improved Cowpea ...

    African Journals Online (AJOL)

    The results show that land and labour problems, marketing problems, poor technical information, cultural incompatibility, high cost of farm inputs and unavailability of necessary inputs were the major factors constraining the use of improved cowpea technologies in the area. These findings suggest that there is an urgent ...

  11. Can Neutron stars constrain Dark Matter?

    DEFF Research Database (Denmark)

    Kouvaris, Christoforos; Tinyakov, Peter

    2010-01-01

    temperature that could in principle be detected. Due to their compactness, neutron stars can acrete WIMPs efficiently even if the WIMP-to-nucleon cross section obeys the current limits from direct dark matter searches, and therefore they could constrain a wide range of dark matter candidates....

  12. Client's constraining factors to construction project management ...

    African Journals Online (AJOL)

    This study analyzed client's related factors that constrain project management success of public and private sector construction in Nigeria. Issues that concern clients in any project can not be undermined as they are the owners and the initiators of project proposals. It is assumed that success, failure or abandonment of ...

  13. A Constrained Vision of the Writing Classroom.

    Science.gov (United States)

    Phelps, Louise Wetherbee

    1992-01-01

    Proposes that writing teachers and administrators think, first, in terms of the truly political realities--the situated interconnections of interests, accidents, luck, and consequences--that constrain our abilities to realize utopian goals and, second, in terms of ethical constraints to which they are willing to be bound by. (RS)

  14. Algorithm Solves Constrained and Unconstrained Optimization Problems

    Science.gov (United States)

    Denson, M. A.

    1985-01-01

    Is quasi-Newton iteration utilizing Broyden/Fletcher/Goldfarb/Shanno update on inverse Hessian matrix. Capable of solving constrained optimization unconstrained optimization and constraints only problems with one to five independent variables from one to five constraint functions and one dependent function optimized.

  15. Entanglement-assisted capacity of constrained channels

    Science.gov (United States)

    Holevo, A. S.

    2003-07-01

    In this paper we fil a gap in previous work by proving the conjectured formula for the antanglement-assisted capacity of quantum channel with additive input constraint (such as Bosonic Gaussian channel). The main tools are the coding theorem for classical-quantum constrained channels and a finite dimensional approximation of the input density operators for the entanglement-assisted capacity.

  16. Kappa opioid receptor activation potentiates the cocaine-induced increase in evoked dopamine release recorded in vivo in the mouse nucleus accumbens.

    Science.gov (United States)

    Ehrich, Jonathan M; Phillips, Paul E M; Chavkin, Charles

    2014-12-01

    Behavioral stressors increase addiction risk in humans and increase the rewarding valence of drugs of abuse including cocaine, nicotine and ethanol in animal models. Prior studies have established that this potentiation of drug reward was mediated by stress-induced release of the endogenous dynorphin opioids and subsequent kappa opioid receptor (KOR) activation. In this study, we used in vivo fast scan cyclic voltammetry to test the hypothesis that KOR activation before cocaine administration might potentiate the evoked release of dopamine from ventral tegmental (VTA) synaptic inputs to the nucleus accumbens (NAc) and thereby increase the rewarding valence of cocaine. The KOR agonist U50488 inhibited dopamine release evoked by either medial forebrain bundle (MFB) or pedunculopontine tegmental nucleus (PPTg) activation of VTA inputs to the shell or core of the mouse NAc. Cocaine administration increased the dopamine response recorded in either the shell or core evoked by either MFB or PPTg stimulation. Administration of U50488 15 min before cocaine blocked the conditioned place preference (CPP) to cocaine, but only significantly reduced the effect of cocaine on the dopamine response evoked by PPTg stimulation to NAc core. In contrast, administration of U50488 60 min before cocaine significantly potentiated cocaine CPP and significantly increased the effects of cocaine on the dopamine response evoked by either MFB or PPTg stimulation, recorded in either NAc shell or core. Results of this study support the concept that stress-induced activation of KOR by endogenous dynorphin opioids may enhance the rewarding valence of drugs of abuse by potentiating the evoked dopamine response.

  17. ActRIIA and BMPRII Type II BMP receptor subunits selectively required for Smad4-independent BMP7-evoked chemotaxis.

    Directory of Open Access Journals (Sweden)

    Jeanette C Perron

    2009-12-01

    Full Text Available Bone morphogenetic protein (BMP-evoked reorientation and chemotaxis of cells occurs with rapid onset and involves events local to the cell membrane. The signaling pathways underlying these rapid processes likely diverge from those mediating classical transcriptional responses to BMPs but it remains unclear how BMP receptors are utilized to generate distinct intracellular mechanisms. We show that BMP7-evoked chemotaxis of monocytic cells depends on the activity of canonical type II BMP receptors. Although the three canonical type II BMP receptors are expressed in monocytic cells, inhibition of receptor subunit expression by RNAi reveals that ActRIIA and BMPRII, but not ActRIIB, are each essential for BMP7-evoked chemotaxis but not required individually for BMP-mediated induction. Furthermore, the chemotactic response to BMP7 does not involve canonical Smad4-dependent signaling but acts through PI3K-dependent signaling, illustrating selective activation of distinct intracellular events through differential engagement of receptors. We suggest a model of a BMP receptor complex in which the coordinated activity of ActRIIA and BMPRII receptor subunits selectively mediates the chemotactic response to BMP7.

  18. Origin of facilitation of motor-evoked potentials after paired magnetic stimulation: direct recording of epidural activity in conscious humans.

    Science.gov (United States)

    Di Lazzaro, V; Pilato, F; Oliviero, A; Dileone, M; Saturno, E; Mazzone, P; Insola, A; Profice, P; Ranieri, F; Capone, F; Tonali, P A; Rothwell, J C

    2006-10-01

    A magnetic transcranial conditioning stimulus given over the motor cortex at intensities below active threshold for obtaining motor-evoked potentials (MEPs) facilitates EMG responses evoked at rest in hand muscles by a suprathreshold magnetic stimulus given 10-25 ms later. This is known as intracortical facilitation (ICF). We recorded descending volleys produced by single and paired magnetic motor cortex stimulation through high cervical epidural electrodes implanted for pain relief in six conscious patients. At interstimulus intervals (ISIs) of 10 and 15 ms, although MEP was facilitated, there was no change in the amplitude or number of descending volleys. An additional I wave sometimes was observed at 25 ms ISI. In one subject, we also evaluated the effects of reversing the direction of the induced current in the brain. At 10 ms ISI, the facilitation of the MEPs disappeared and was replaced by slight suppression; at 2 ms ISI, there was a pronounced facilitation of epidural volleys. Subsequent experiments on healthy subjects showed that a conditioning stimulus capable of producing ICF of MEPs had no effect on the EMG response evoked by transmastoidal electrical stimulation of corticospinal tract. We conclude that ICF occurs because either 1) the conditioning stimulus has a (thus far undetected) effect on spinal cord excitability that increases its response to the same amplitude test volley or 2) that it can alter the composition (but not the amplitude) of the descending volleys set up by the test stimulus such that a larger proportion of the activity is destined for the target muscle.

  19. Constrained target controllability of complex networks

    Science.gov (United States)

    Guo, Wei-Feng; Zhang, Shao-Wu; Wei, Ze-Gang; Zeng, Tao; Liu, Fei; Zhang, Jingsong; Wu, Fang-Xiang; Chen, Luonan

    2017-06-01

    It is of great theoretical interest and practical significance to study how to control a system by applying perturbations to only a few driver nodes. Recently, a hot topic of modern network researches is how to determine driver nodes that allow the control of an entire network. However, in practice, to control a complex network, especially a biological network, one may know not only the set of nodes which need to be controlled (i.e. target nodes), but also the set of nodes to which only control signals can be applied (i.e. constrained control nodes). Compared to the general concept of controllability, we introduce the concept of constrained target controllability (CTC) of complex networks, which concerns the ability to drive any state of target nodes to their desirable state by applying control signals to the driver nodes from the set of constrained control nodes. To efficiently investigate the CTC of complex networks, we further design a novel graph-theoretic algorithm called CTCA to estimate the ability of a given network to control targets by choosing driver nodes from the set of constrained control nodes. We extensively evaluate the CTC of numerous real complex networks. The results indicate that biological networks with a higher average degree are easier to control than biological networks with a lower average degree, while electronic networks with a lower average degree are easier to control than web networks with a higher average degree. We also show that our CTCA can more efficiently produce driver nodes for target-controlling the networks than existing state-of-the-art methods. Moreover, we use our CTCA to analyze two expert-curated bio-molecular networks and compare to other state-of-the-art methods. The results illustrate that our CTCA can efficiently identify proven drug targets and new potentials, according to the constrained controllability of those biological networks.

  20. An inventory and update of jealousy-evoking partner behaviours in modern society.

    NARCIS (Netherlands)

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

    2010-01-01

    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