Auditory Evoked Potentials P50: Pure-tones vs Clicks. There is a Similar Supression?

Objective:Clinical application of middle-latency auditor evoked potential (MLAEPs) has been increasing, highlighting the importance of understanding the nature of P50,a componentof middle-latency auditory evoked potential. We manipulated stimulus frequency bands in auditory stimuli in order to investigate the nature of P50 in human auditory evoked potentials.Methods:Two paradigms have been used to obtain P50: one is a conditioning /testing paradigm in which paired of pure tone (1000Hz) are delivered, and the other was presented paired of clicks, both with an intensity of 60 dB sound pressure level above the auditory threshold. A total of 30 healthy volunteers were recruited for this study among Center of genetic engineering (fifteen man and fifteen women, mean age of 36,5). All without consumption of caffeine, cigarettes and drugs. Results:No statistically significant differences occurred between the P50 amplitudes and latencies for the pure tone and those for the clicks.Conclusions:Ourpresent results indicate that P50 in humans may reflect a feed-forward mechanism of the brain where a preceding stimulus drives sensory gating mechanisms in preparation for a second stimulus, but the contained frequency doesn't influence on the P50. Both types (tones or clicks) can be used in the exploration of patient with this evoked potential

Exploring bite marks on different types of skin tones / Explorando as marcas de mordida em diferentes tipos de tons de pele

The analysis of bite marks is a challenging and convoluted part of Forensic Odontology. Various interrelated factors such as location of the bite and skin elasticity complicate the bite mark analysis. The relationship between the bite mark and the biochemical properties of skin has been well-documented but there is need to consider the variety of skin tones as a factor to explore. The aim of this pilot study was to analyse the appearance of bite marks on 5 different types of skin tones of 15 subjects (6 males and 9 females) from 11 nationalities and age ranged from 21 to 46 years. A pair of 3D printed dental cast was transferred onto a mechanical apparatus for production of experimental bitemarks by using 12.5 kg of weight. Common imaging modalities including conventional, infrared and ultraviolet light were used to record the bite mark images for following visual assessment. The different skin tones were categorized using Fitzpatrick scale (1975) and a colour chart was used to compare the changes on skin after 15 minutes of bite registration. According to the results, the force was well tolerated by the subjects producing a well-defined bite mark, although males showed a less prominent mark than females irrespective of the skin tone and nationality. Neither bruises nor significant changes in the colour of bite mark could be appreciated among the subjects. The different types of skin tones did not affect the registration of bite mark applying a force of 122.5.N for 15 seconds in this sample

A análise das marcas de mordida é a parte mais desafiadora e complicada da Odontologia Forense. Vários fatores inter-relacionados, como a localização da mordida e a elasticidade da pele, complicam a análise da marca de mordida. A relação entre a marca de mordida e as propriedades bioquímicas da pele tem sido bem documentada, mas é preciso considerar a variedade de tons de pele como um fator a ser explorado. O objetivo deste estudo piloto foi analisar o aparecimento de marcas de mordida em 5 tipos diferentes de tons de pele de 15 indivíduos (6 homens e 9 mulheres) de 11 nacionalidades e idades entre 21 a 46 anos. Um par de modelos dentários impressos em 3D foi transferido para um aparelho mecânico para a produção de marcas de mordida experimentais usando 12,5 kg de peso. Modalidades de imagem digital como convencional, infravermelha e ultravioleta foram usadas para registrar as imagens da marca de mordida para posterior avaliação visual. Os diferentes tons de pele foram categorizados usando a escala de Fitzpatrick e uma cartela de cores foi usada para comparar as alterações na pele após 15 minutos de registro da mordida. De acordo com os resultados a força foi bem tolerada pelos sujeitos, produzindo uma marca de mordida bem definida, embora os homens mostraram uma marca menos proeminente do que as mulheres, independentemente do tom da pele e da nacionalidade. Nenhum hematoma ou mudanças significativas nas cores das marcas de mordida foram encontrados entre os indivíduos. Os diferentes tipos de tons de pele não afetaram o registro da marca de mordida aplicando uma força de 122,5 N por 15 segundos nesta amostra.

The categorical perception of Mandarin tones by children with speech development disorders / 中华物理医学与康复杂志

Objective To investigate the perception of Mandarin's tones by children with speech development disorders so as to provide a theoretical basis for clinical rehabilitation.Methods Thirty children with speech development disorders (DPDs) aged 4 to 6 were matched with 30 healthy counterparts as a control group.Both groups underwent the tone perception experiment,which included tone identification and discrimination tasks.The speech stimuli were 11 computer-simulated voices expressing a continuum of sounds from Mandarin speech ranging from /bá/ to /bà/.The two groups were compared in their ability to identify and differentiate the tones.Results Both groups showed typicalS-shaped identification curves in a category pattern.The category boundaries of the control group were between stimulus steps 6 and 7,significantly different from those of the experimental group where the boundary fell between stimulus steps 5 and 6.On the distinguishing curve,both groups presented obvious peak values.The stimulus steps of the peaks and the crossing points of the identification curves were consistent.In addition,the average ahsolnte value (b1) of the identification curve and the peaks' degree of steepness (DP) of the DPD group's distinguishing curve were significantly lower than those of the control group.At the same time,the average boundary width (Wcb) was significantly higher than that of the control group.Conclusion Children with speech development disorders perceive Mandarin tones with categories different from those of normal children.They may have difficulty in perceiving tones,which might be an important factor leading to pronunciation errors.

Native Hakka speakers' identification of Cantonese tones: A comparative analysis / 中华物理医学与康复杂志

Objective To investigate the features of native Hakka speakers' ability to identify Cantonese tones.Methods Twenty native Cantonese speakers and 12 native Hakka speakers were given the Hongkong Cantonese tone identification test.Results Neither group was troubled by similar vowel and consonant sounds.The Cantonese group could identify all tones well except distinguishing tones 5 and 2 (89％) and tones 4 and 6 (89％).The Hakkas had the most difficulty distinguishing tones 3 and 6 (70.0％),but significant differences were observed between the two groups in the identification of tones 2 and 5 and 2 and 4.Conclusion A native Hakka speaker's ability to identify Cantonese tones may be closely related to the tone's pitch,tonal patterns as well as the Hakka tone system.

Cortical Auditory Event Related Potentials (P300) for Frequency Changing Dynamic Tones

BACKGROUND AND OBJECTIVES: P300 has been studied with a variety of stimuli. However, the nature of P300 has not been investigated for deviant stimuli which change its characteristics from standard stimuli after a period of time from onset. SUBJECTS AND METHODS: Nine young adults with normal hearing participated in the study. The P300 was elicited using an oddball paradigm, the probability of standard and deviant stimuli was 80% and 20% respectively. Six stimuli were used to elicit P300, it included two pure-tones (1,000 Hz and 2,000 Hz) and four tone-complexes (tones with frequency changes). Among these stimuli, 1,000 Hz tone served as standard while others served as deviant stimuli. The P300 was recorded in five separate blocks, with one of the deviant stimuli as target in each block. Electroencephalographic was recorded from electrode sites Fz, Cz, C3, C4, and Pz. Latency and amplitude of components of the cortical auditory evoked potentials were measured at Cz. RESULTS: Waveforms obtained in the present study shows that, all the deviant stimuli elicited obligatory P1-N1-P2 for stimulus onset. 2,000 Hz deviant tone elicited P300 at a latency of 300 ms. While, tone-complexes elicited acoustic change complex (ACC) for frequency changes and finally elicited P300 at a latency of 600 ms. In addition, the results showed shorter latency and larger amplitude ACC and P300 for rising tone-complexes compared to falling tone-complexes. CONCLUSIONS: Tone-complexes elicited distinct waveforms compared to 2,000 Hz deviant tone. Rising tone-complexes which had an increase in frequency elicited shorter latency and larger amplitude responses, which could be attributed to perceptual bias for frequency changes.

Dichotic Perception of Modern Chinese Tones by Mexican Chinese Learners / 听力学及言语疾病杂志

Objective To investigate the relationship between the advantageous ear (cerebral hemisphere) of Spanish-speaking Mexican Chinese learners and category's perception of the Chinese tones .Methods Four types of Chinese syllables tones were used as experimental materials with dichotic listening technology to test the Spanish -speaking Mexican Chinese learners who studied Chinese about 60~70 hours ,20~27years old(mean is 21 .29 ± 2 .3) , and then the correct response time and error rate were made a count on .Results In terms of reaction time for iden-tifying the four Chinese tones ,the Spanish-speaking M exican Chinese learners's reaction to the first tone suggested that their right ear were the advantageous ear (the left cerebral hemisphere) .As for the main effects of both hands , the first tone suggested that the Spanish -speaking Mexican Chinese learners had a left hand advantage .The Span-ish -speaking Mexican Chinese learners's reaction to the sencond tone suggested that their right ear were the advan-tageous ear(the left cerebral hemisphere) with the left hand used as a hand of reaction ,and the Spanish-speaking Mexican Chinese learners's reaction to the second tone suggested that their left ear were the advantageous ear (the right cerebral hemisphere) with the right hand used as a hand of reaction .In terms of error rate for identifying the four Chinese tones ,the Spanish-speaking M exican Chinese learners's reaction to the third tone suggested that their right ear were the advantageous ear (the left cerebral hemisphere) with the left or right hand used as a hand of reac-tion ,but the fourth's identification didn't show the advantageous ear .Conclusion M exican Chinese learners identify the first and third tones of Modern Chinese the right ear (the left cerebral hemisphere) main effects were significant . Identifying the second tone of Modern Chinese ,Mexican Chinese learners'right ears (the left cerebral hemisphere)or right ears (the left cerebral hemisphere) were the advantageous ear (the advantageous cerebral hemisphere) or not depend on the reaction of hands .Identifying the fourth tones ,Mexican Chinese learners'left or right ear (left or right cerebral hemisphere) main effects weren't significant .

Efectos de la variación de la intensidad de los tonos primarios sobre las amplitudes de Emisiones Otoacústicas Producto de Distorsión (EOApd) en sujetos con audición dentro de rangos de normalidad / Effects of varying the intensity of the primary tones on the amplitudes of Distortion Product Otoacoustic Emissions (OAEdp) in patients with normal hearing

Introducción: Las emisiones otoacústicas (EOA) son sonidos generados por las células ciliadas externas (CCE). Se ha visto que la generación y registro de las EOA evocadas depende de factores técnicos de evaluación como el nivel de intensidad de los tonos primarios, relación frecuencial entre los tonos, etc. Objetivos: Estudiar el efecto de la variación de la intensidad de los tonos primarios en la amplitud de la respuesta de las EOA producto de distorsión (pd) en individuos con audición normal. Material y método: Se evaluaron 35 individuos a los cuales se les midieron EOApd utilizando diferentes intensidades de tonos primarios: Intensidad baja (I1=50dBSPL e I2=50dBSPL), intensidad media (I1=55dBSPL e I2=65dBSPL) e intensidad alta (I1=70dBSPL e I2=70dBSPL). Resultados: Se observó que para tonos primarios a bajas intensidades (I1=50dBSPL e I2=50dBSPL) existe una disminución tanto en amplitud y presencia de las EOApd, mientras que para tonos primarios a intensidades mayores (I1=55dBSPL e I2=65dBSPL - I1=70dBSPL e I2=70dBSPL) se evidenció un aumento en amplitud y presencia de EOApd en los sujetos estudiados. Conclusión: Se evidencian diferencias estadísticamente significativas en la amplitud de las EOApd al variar la intensidad de los tonos primarios. Por lo cual se puede establecer que las intensidades medias-altas son las más adecuadas para la evaluación de EOApd en sujetos con audición normal.

Introduction: Otoacoustic emissions (OAE) are sounds produced by outer hair cells. The generation and recording of evoked OAE depends on technical factors such as level of intensity of primary tones, frequency relationship between the tones, etc. Aim: To study the effect of varying the intensity of primary tones in the amplitude of the response of Distortion Product OAE (DP) in individuals with normal hearing. Material and method: 35 individuals were measured using different intensities OAEdp primary tones: Low Intensity (I1= I2 =50dBSPL 50dBSPL e), Medium Intensity (11= I2 =65dBSPL 55dBSPL e) and High Intensity (I1 =70dBSPL and I2 =70dBSPL). Results: Using Low primary tones (I1 =I2 =50dBSPL 50dBSPL) there is a decrease in amplitude and presence of DPOAE, while for primary tones at higher intensities (I1 and I2 = = 55dBSPL 65dBSPL -11 =70dBSPL and I2 =70dBSPL) an increase in amplitude and presence of OAEdp in subjects with normal hearing was observed . Conclusion: There are statistically significant differences in OAEdp amplitude by varying the intensity of the primary tones. Therefore medium-high intensities are best suited for the evaluation of OAEdp in subjects with normal hearing.

The mini-invasive surgical treatment for cholelithiasis disease experiences in the primary hospital / 中国基层医药

Objective To study the mini-invasive surgical treatment for cholelithiasis disease in the primary hospital. Methods Laparoseope,duodenoscope and choledochoscope were combined to treat 293 cases with cholelith-iasis which included 2 cases cholecystolithisasis, 131 cases were cholecystolithiasis with secondary choledocholith,28 cases with primary choledocholith,39 cases with calculus of intrahepatic duct,93 cases with calculus of intrahepatic or extrahepatic duct. Results The program had minor trauma, mild suffering, and less operative complications,compared with traditional open operations. Conclusion The combined treatment of laparoscopy, duodenoscopy, choledochoscope and surgery for the cholelithiasis in the primary hospital is feasible, safe and effective.

The Pre-attentive Processes of Chinese Tones Transmitted by Cochlear Implant Users and Normal Hearing Subjects / 听力学及言语疾病杂志

Objective Event related potentials (ERP), especially mismatch negativity (MMN), as index, was utilized to study the processing of Chinese tones recognized by cochlear implant (CI) users and normal hearing subjects. Methods The auditory materials were Chinese words with four tones consisting of three different oddball blocks. The ERP and MMN of CI users and normal hearing subjects were recorded and analyzed in relation to the discrimination of those tones as tested. Results The ERP and MMN of CI users and normal hearing subjects were presented. The MMN of CI users includes two negative waves: the first negative wave (MMN1) occurred approxi-mately 100 ms, and the second wave (MMN2) at 300 ms. The MMN of normal hearing subjects includes two nega-tive waves too: the first negative wave (MMN1) occurred approximately 150 ms, and the second wave (MMN2) al-so at 300 ms. The MMN1 peak latency of CI users was obviously shorter than that of normal hearing subjects and the MMN2 peak latency of CI users shorter than that of normal hearing subjects too, but the difference of MMN2 peak latency between CI users and normal hearing subjects was not as significant as that of MMN1. Conclusion In the preattentive stage, CI users could process Chinese tones as normal hearing subjects, but compared with the pro-cessing of normal hearing subjects, there are some differences in the processing of CI users.