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Abstract Introduction Tinnitus is sound perception in the absence of a sound source. Changes in parameters of latency and amplitude on the auditory event related potentials or long latency potentials waves have been cited in tinnitus patients when compared to a control group. Objective To perform an assessment of scientific evidence that verifies the possibility of alterations in latency or amplitude of the waves of event related potentials in individuals with tinnitus. Methods By using SciELO, Lilacs, ISI Web and PubMed, scientific databases, a review was performed. Articles published in English, Portuguese, French and Spanish that correlated tinnitus with changes in event related potentials were included in this review. Results Twelve articles were located, however only eight fulfilled the criteria for inclusion. Conclusion The sample of selected studies demonstrate that the long latency auditory evoked potentials related to events between the control and tinnitus patients showed some changes in latency and or amplitude in tinnitus patients. There are changes in event-related potentials when comparing patients with tinnitus and the control group. These changes take place considering the severity of tinnitus, tinnitus site of lesion, and capacity for changes after interventions. The event related potentials can help to determine the neurotransmitter involved in tinnitus generation and evaluate tinnitus treatments.
Resumo Introdução O zumbido é a percepção de um som na ausência de uma fonte sonora. Mudanças nos parâmetros de latência e amplitude nas ondas dos potenciais evocados auditivos relacionados a eventos ou potenciais de longa latência foram citadas em pacientes com zumbido quando comparados a um grupo controle. Objetivo Realizar uma avaliação de evidências científicas que verifiquem a possibilidade de alterações na latência ou amplitude das ondas de potenciais evocados auditivos relacionados a eventos em indivíduos com zumbido. Método Foi feita uma revisão a partir dos bancos de dados científicos SciELO, Lilacs, ISI Web e PubMed. Artigos publicados em inglês, português, francês e espanhol que correlacionavam zumbido com alterações nos potenciais evocados auditivos relacionados a eventos foram incluídos. Resultados Foram localizados 12 artigos, porém apenas oito preencheram os critérios de inclusão. Conclusão A amostra de estudos selecionados demonstra que os potenciais evocados auditivos de longa latência relacionados a eventos entre os pacientes-controle e com zumbido apresentaram algumas alterações na latência e/ou amplitude nos pacientes com zumbido. Há mudanças nos potenciais relacionados a eventos ao comparar pacientes com zumbido e o grupo controle. Essas alterações consideram a gravidade do zumbido, o local da lesão do zumbido e a capacidade de alterações após as intervenções. Os potenciais evocados auditivos relacionados a eventos podem ajudar a determinar o neurotransmissor envolvido na geração do zumbido e avaliar os tratamentos para o zumbido.
Subject(s)
Humans , Tinnitus/physiopathology , Evoked Potentials/physiology , Evoked Potentials, Auditory/physiology , Attention , Tinnitus/psychology , Event-Related Potentials, P300/physiology , Evidence-Based MedicineABSTRACT
OBJECTIVES: The goal of this study is to measure the auditory Event Related Potentials in Filipino patients with schizophrenia, their siblings and comparing them with normal controls. Specifically the P300 amplitude and latency measurements of schizophrenic patients would also be correlated to sociodemographic variables such as age, duration of illness and positive and negative symptoms of schizophrenia.METHODOLOGY: Patients with schizophrenia after consenting to participate in the study were screened using the Positive and Negative Symptom Scale. The auditory event related potentials (ERP) of the parietal electrode of these patients and their siblings as well as a control group of healthy individuals from the community were measured and compared.RESULTS: Comparison of P300 parameters among 20 patients with schizophrenia, 20 siblings and 20 controls using ANOVA showed that the P300 amplitude of schizophrenic patients was markedly reduced compared with the other 2 groups. P300 latency values were markedly prolonged in both schizophrenia and their siblings when compared to the control group. Analysis of the data revealed that P300 latency had a positive correlation with the duration of positive and negative symptoms. There was also an inverse correlation with positive symptomatology.CONCLUSION: There was a decreased P300 amplitude and prolonged P300 latency in Filipino Schizophrenic patients. P300 parameters in schizophrenic patients were correlated to age, duration of symptoms and positive and negative symptoms.
Subject(s)
Humans , Male , Female , Schizophrenia , Patients , PhilippinesABSTRACT
Objective To study the impact of Chitosan Lecithin on the mild cognitive impairment(MCI) patients' semantic understanding by event-related potential N400.Methods 32 patients with MCI were screened from 500 elder people aged Court in Weifang by mini-mental state examination (MMSE) scale,and were divided into two groups:the observation group ( n=16) and the control group ( n=16) by the table of random numbers.The observation group were given Chitosan Lecithin while the control group were given an equal dose of placebo.The intervention time was 2 months.The subjects were asked to conduct semantic judgement by semantic violation experiment.Thirty-two channels electroencephalogram(EEG) was recorded by Neuroacan Nuamps Systerm and analyzed data.Results 1 ) Specific component N400 was found in both groups,which was distributed at the frontal,central and parietal regions.2 ) The observation group reaction time and correct rate were respectively (965.13 ± 178.07 ) ms and ( 92.56 ± 2.36 ) ％ ,while the control group were respectively ( 1126.13 ± 252.77 ) ms and (85.28 ± 5.73 )％,with significant difference(P ＜ 0.05 ).3 ) Compared with N400 in control group,N400 latency was shorter ( (425.28 ±47.26) ms vs (456.19 ± 37.75 ) ms,F=6.01,P＜0.05) and amplitude was higher ( (4.79 ±2.18)μV vs (3.59 ± 1.33) pV,F=5.96,P＜0.05).Conclusion Chitosan lecithin has the effect of N400 latency and amplitude,it may be helpful for the patients of MCI in semantic understanding.
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Objective To investigate neural correlates of the retrieval of temporal order.Methods ERP of 19 channels was recorded from 17 healthy young students while they performed a recency judgment task,a recognition task and a visual discrimination task separately,which were based on Sternberg paradigm.One-way ANOVA of repeated-measurement and post-hoc paired comparisons were carried out for both the task factor(temporal order,recognition and control)and the temporal distance factor correspondingly.The latter contains 3 intervals (1,2 and 3)between the targets.Results The temporal distance effect was significant:the closer targets correspond to longer reaction time((745.5±106.1)ms,(711.7±102.2)ms,(653.7±81.5)ms;F_((1.28,20.48))=43.37,P=0.00]and higher error rate((62.8±7.0)%,(72.5±5.4)%,(84.5±6.4)%;F_((1.32,21.11))=135.99,P=0.00].Significant behavioral effect of the task factor was also found for both reaction time(F_((1.32,21.11))=135.99,P=0.00)and error rate(F_((2,32))=200.31,P=0.00).No significant behavioral difference was found between the temporal order group and the recognition group.The spatiotemporal pattern of statistical parametric mapping(SPM)suggested the ERP effects of temporal order were presented in left temporal region (260～270 ms),bilateral parietal-occipital areas(280～290 ms),and bilateral parietal lobes(300～400 ms)prominently.No ERP effect was found between the temporal order task and the recognition task.Conclusions The neural correlates of the temporal distance effect exist in bilateral parietal regions.Temporal order as well as object information processing involves similar cerebral regions during the retrieval period.
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Objective To study early face processing of mild cognitive impairment patients by using ERP method．Methods Sixteen healthy old man(normal group)and sixteen mild cognitive impairment patients(MCI group)served as subjects in experiment．Two runs of 300 stimuli(duration：50ms)of 3 facial and 3 non-facial pictures were randomly presented with equal probability(ISI：from 1000ms to 1500ms randomly)，and the subjects were asked to react to facial stimuli and non-facial stimuli by pressing the left button and risht button respectively as quickly as possible．Thirty-two channels electroencephalogram(EEG)Was recorded by Neuroscan Nuamps Systern．Results 1)Specific-face component N170 was found in both groups．Which was distributed at the temporal-occipital region．2)Compared with N170 in normal group，N170 amplitude Was significantly lower((-4．42±0．28)Μv vs(-7．00±0．28)Μv，F=41．52，P<0．01)at temporal-occipital region and delayed((158．91±2．17)ms vs(140．97±2．17)ms，F=34．09，P<0．01) in mild cognitive impairment group．Conclusion The early face processing mechanism of mild cognitive impairment patients may be different from normal people．
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@#ObjectiveTo explore the neural basis of visual completion for the occluded faces.Methods2 types of visual stimuli were presented randomly: pictures of complete faces,pictures of incomplete faces(the occluded part was the left-top quadrant).Subjects were instructed to perform a gender discrimination task while event-related potentials(ERPs) were recorded.ResultsCompared with complete faces,incomplete faces enhanced the amplitude of N1 on the occipito-temporal scalp bilaterally,with the right hemisphere advantage.The peak latency of N2 elicited by incomplete faces was delayed compared with that of complete faces.ConclusionThe enhancement of N1 is related to visual completion processing that requires additional time.
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@#ObjectiveTo explore the neural basis of visual completion for the occluded faces.Methods2 types of visual stimuli were presented randomly: pictures of complete faces,pictures of incomplete faces(the occluded part was the left-top quadrant).Subjects were instructed to perform a gender discrimination task while event-related potentials(ERPs) were recorded.ResultsCompared with complete faces,incomplete faces enhanced the amplitude of N1 on the occipito-temporal scalp bilaterally,with the right hemisphere advantage.The peak latency of N2 elicited by incomplete faces was delayed compared with that of complete faces.ConclusionThe enhancement of N1 is related to visual completion processing that requires additional time.
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Objective To study early face processing of internet addiction patients by using ERP method. Methods Ten healthy young man 18~21 years and 10 internet addiction patients 17~22 years served as subjects in experiment. Two runs of 300 stimuli (duration: 50 ms) of 3 facial and 3 non-facial pictures were randomly presented with equal probability (ISI: from 1 000 ms to 1 500 ms randomly), and the subjects were asked to react to facial stimuli and non-facial stimuli by pressing the left button and right button respectively as quickly as possible. Thirty two channel electroencephalogram (EEG) was recorded by Neuroscan Nuamps System. Results 1) Specific-face component Nd170 (face N170 minus object N170) was found in both groups, which was distributed at the temporal-occipital region in control groups but at occipital region in internet addiction group; 2) Compared with Nd170 in internet addiction group, Nd170 was significantly lower at occipital negion and delayed in control group. Conclusion The early face processing mechanism of internet addiction patients may be different from normal people.