Les fuseaux de sommeil sont générés par le noyau réticulaire thalamique puis transmis dans la boucle thalamo-corticale durant le sommeil lent. Ils sont considérés comme ayant un rôle protecteur du sommeil en inhibant les entrées sensorielles. L'objectif de notre travail était de tester ce rôle inhibiteur sur les réactions d'éveil et les réponses évoquées par des stimulations nociceptives chez l'homme en menant trois études électrophysiologiques au cours de nuits entières. Les deux premières études ont utilisé des stimuli laser thermo-nociceptifs délivrés pendant ou en dehors de fuseaux. Les réponses cérébrales étaient obtenues par enregistrements de surface chez des sujets sains, ou intracérébraux chez des patients épileptiques. Les résultats n'ont pas montré de différence significative des réactions d'éveil ou des réponses évoquées, que les stimuli aient été délivrés pendant ou en dehors de fuseaux. Ceci était le cas dans l'étude de surface, mais également dans celle en intracérébral dans laquelle les fuseaux étaient détectés dans le thalamus et les réponses analysées dans l'insula, connue pour répondre systématiquement aux stimuli nociceptifs. Dans la troisième étude, afin d'augmenter la quantité de stimuli, des stimulations électriques ont été utilisées à intensité nociceptive. La relation temporelle entre fuseau et traitement sensoriel a ainsi été étudiée avec des enregistrements de surface à haute densité chez des sujets sains. Les réponses évoquées, présentes dans tous les cas, étaient de plus grande amplitude lors des stimuli délivrés autour du début du fuseau. Ainsi, l'effet inhibiteur du fuseau de sommeil ne semble pas s'appliquer au traitement des informations nociceptives et la modulation des réponses corticales selon le moment du fuseau pourrait refléter l'influence de l'onde lente corticale / Sleep spindles are generated by thalamic reticular nuclei and transmitted into the thalamo-cortical network during nonREM sleep. They are commonly thought to have a sleep-protecting role by inhibiting sensory inputs. The aim of our work was to test their inhibitory effect on behavioural and evoked responses to nociceptive inputs in humans by conducing three electrophysiological experiments during a whole night of sleep. The first two experiments used thermo-nociceptive laser stimuli delivered during or apart from sleep spindles. Cerebral responses were obtained with surface recordings in healthy subjects, or intracerebral ones in epileptic patients. Results showed no significant difference in arousal reactions and cortical evoked responses to stimuli delivered during or apart from sleep spindles. This was the case on surface recordings as well as on intracerebral ones in which spindles were detected within the thalamus while responses were analysed in the insula, known to systematically respond to nociceptive stimuli. In the third experiment, in order to increase the rate of stimuli, electrical ones were used at nociceptive intensities. The relationship between spindle activity and sensory processing was then investigated with surface high-density recordings in healthy subjects. Evoked responses were present in any case, but of higher amplitude around the initiation of spindle activity. Thus, the spindles inhibitory effect of sensory processing does not seem to apply to nociceptive inputs and the modulation of cortical responses according to the timing of spindle might reflect the influence of the slow oscillation

Acromegalia à uma doenÃa endÃcrina rara. Poucos estudos avaliaram sua associaÃÃo com deficiÃncia auditiva (DA) ou distÃrbios de conduÃÃo do impulso neural auditivo.Osresultados sÃo conflitantes. O objetivo à avaliar a transmissÃo auditiva central e perifÃrica em pacientes com acromegalia. AlÃm disso, avaliar a prevalÃncia e caracterÃsticas da DA em pacientes com acromegalia. Foi feito um estudo transversal com 36 pacientes com acromegalia de um ambulatÃrio especializado em Fortaleza-CearÃ. Foram excluÃdos pacientes com otoscopia anormal ou com histÃria familiar de deficiÃncia auditiva, uso de ototÃxicos ou exposiÃÃo a ruÃdo ocupacional. Inicialmente, o grupo foi avaliado por meio de audiometria tonal limiar. Considerou-se deficiÃncia auditiva (DA) quando a mÃdia dos tons puros foi > 25DbNA para baixas freqÃÃncias (250, 500, 1000 e 2000 Hz) ou altas freqÃÃncias (3000, 4000, 6000 e 8000 Hz).O grupo foi dividido em: acromegalia com DA (Acro DA) e sem DA (Acro NDA) e comparados quanto aos nÃveis hormonais e parÃmetros metabÃlicos. Posteriormente, este grupo de pacientes com acromegalia foi dividido em 2 subgrupos: com (n=16) e sem (n=20) diabetes ou intolerÃncia à glicose de jejum (DM/IGJ). Os resultados foram comparados entre os subgrupos e grupo controle (n=20) quantos aos parÃmetros dos potenciais evocados auditivos de tronco encefÃlico (PEATE). Para avaliar a normalidade da distribuiÃÃo foi utilizado o teste de Kolmogorov-Smirnov quando necessÃrio. Utilizou-se os testes qui-quadrado, t de Student e coeficiente de correlaÃÃo de Pearson. O nÃvel de significÃncia estatÃstica escolhido foi p<0.05 (statistical package for social sciences-SPSS 12.0). Dos 36 pacientes estudados, 14 (38,9%) mostraram DA sensorioneural (Acro DA), sendo em 9 casos bilateral e 5 unilateral. Nenhum apresentou DA mista ou condutiva. A prevalÃncia de DM/IGJ foi similar entre os grupos. As frequÃncias de 250, 3000, 4000, 6000 e 8000 Hz foram as mais afetadas e com padrÃo similar em ambos os lados.O grupo com acromegalia apresentou latÃncia da onda I em orelha direita aumentada em comparaÃÃo ao grupo controle (p=0,007), sem diferenÃa quanto aos intervalos interpicos em nenhum dos lados. Esse padrÃo foi o mesmo quando se comparou o subgrupo com DM/IGJ com o controle.TambÃm houve aumento da latÃncia da onda I na orelha direita em relaÃÃo à orelha esquerda no grupo com acromegalia. Em conclusÃo, mostrou-se uma elevada prevalÃncia de DA sensorioneural em pacientes com acromegalia.No entanto, nÃo se observou relaÃÃo dessa deficiÃncia com caracterÃsticas clÃnicas e metabÃlicas da doenÃa.Pacientes com acromegalia associada DM/IGJ mostraram um retardo no impulso neural no nervo auditivo unilateralmente à direita, evidenciando um efeito neuropÃtico nÃo homogÃneo dos distÃrbios do metabolismo dos carboidratos sobre o nervo auditivo. / Acromegaly is a rare endocrine disease. Few studies have evaluated its association with hearing loss (HL) or disturbance in conduction of the auditory neural impulse. The results are conflicting. The aim is to evaluate central and peripheral auditory transmission in acromegalic patients. Besides, to evaluate the prevalence and characteristics of HL in patients with acromegaly. A cross-sectional study was carried out on 36 patients with acromegaly in a specialized ambulatory in Fortaleza-CearÃ. Patients with abnormal otoscopy, family history of hearing loss, use of ototoxic drugs or occupational noise exposure were excluded. Initially, the group was evaluated by pure tone audiometry. HL was considered when pure tone average was > 25 DBHL for low frequencies (250, 500, 1000 e 2000 Hz) or high frequencies (3000, 4000, 6000 e 8000 Hz). The whole group was divided in: acromegaly with HL (Acro HL) and without HL (AcroNHL) and compared in regards to hormonal levels and metabolic parameters. Additionally that group of patients with acromegaly was divided into 2 subgroups: with (n=16) and without (n=20) diabetes mellitus/impaired glucose tolerance (DM/IGT). The results were compared among these subgroups and a control group (n=20) regarding the brainstem auditory evoked potentials (BAEP) parameters.Kolmogorov-Smirnov test was used to evaluate the normality of distribution when necessary. Qui-quadrado, Student t test and Pearson correlation coefficient were carried out. The level of statistical significance chosen was at p<0.05 (statistical package for social sciences-SPSS 12.0). Among 36 patients evaluated, 14 (38,9%) showed sensorioneural HL (Acro HL), being 9 bilateral and 5 unilateral cases. No one had mixed or conductive HL. The prevalence of diabetes/impaired glucose tolerance was similar between the groups. The frequencies 250, 3000, 4000, 6000 and 8000 Hz were the most affected and with a similar pattern in both ears. The group with acromegaly showed a prolonged peak I latency in the right ear in comparison to the control group (p=0,007), with no difference regarding the interpeak intervals in any sides. This pattern was the same when comparing the DM/IGT subgroup to controls. Also, we found a prolonged peak I latency in the right ear in relation to the left ear in the group with acromegaly.In conclusion, a high prevalence of sensorineural HL was shown in patients with acromegaly. Nevertheless, no correlation was observed between this dysfunction and clinical or metabolic characteristics of the disease. Patients with acromegaly associated with DM/IGT showed a delayed neural impulse in the auditory nerve unilaterally in the right side, evidencing a non-homogenous neuropathic effect of the carbohydrate metabolism disturbances on the auditory nerve.

Objetivo: Avaliar repercussões da exposição ocupacional a uma mistura de solventes orgânicos sobre o desempenho visual de um grupo de frentistas. Método: Foram aplicados testes de ordenamento e discriminação de matizes, campo visual e sensibilidade ao contraste espacial de luminância em 25 frentistas (20 homens, M=36,4 anos, DP=8,9) e 25 controles sem histórico de exposição crônica a solventes (10 homens, M=33,8 anos, DP=8,8). As concentrações metabólitos urinários de tolueno (M=0,3 g/g de creatinina; DP=0,16) e xileno (M=0,1 g/g de creatinina; DP=0,02) e o tempo de trabalho (M=9,6 anos; DP=6,2) foram utilizados como indicativos da exposição dos frentistas. Os participantes foram submetidos a exame oftalmológico, e quando necessário, corrigir a acuidade visual para 20/20. Todas as medidas foram realizadas monocularmente com um olho escolhido ao acaso, com exceção do Potencial Visual Evocado Multifocal (PVEmf) e da campimetria. Para avaliar a visão de cores, utilizamos o Lanthony D15-d e Cambridge Colour Test 2.0. Na campimetria estática automatizada foi utilizado o protocolo branco-branco 24-2 do aparelho Humphrey Field Analyzer II-750i. A atividade elétrica visual cortical foi avaliada com o sistema de PVEmf Veris Science 5.2.4, utilizando um estímulo de 60 setores. A sensibilidade ao contraste espacial de luminância foi avaliada no teste Metropsis, para grades senoidais em 7 frequências espaciais de 0,2 a 20,0 cpg. Resultados: Os escores do grupo de frentistas e do grupo controle foram comparados pelo teste Mann-Whitney U. No teste de discriminação de cores (CCT), houve diferença estatística significativa entre controles e frentistas para a área total da elipse (p<0,01), elipticidade (p<0,05) e limiares nos eixos protan, deutan e tritan (p<0,05). No D15d houve diferença significativa entre os 8 dois grupos (p<0,01). Os dados da campimetria apresentaram diferenças significativas entre os dois grupos para as excentricidades de 90, 150 e 210, além dos valores de MD e PSD (p<0,05). Dos três frentistas avaliados com o PVEmf, todos apresentaram uma diminuição significativa (p<0,05) da amplitude do sinal (em relação a dados normativos) em um mínimo de 30 setores do campo visual, resultado que não foi observado no grupo controle. Nos testes de visão de cores, foi encontrada uma correlação (Spearman) positiva e significativa entre o tempo de trabalho e os índices do Lanthony D15d (p=0,52; p<0,05) e os limiares no eixo deutan (p=0,59; p<0,05). Na campimetria, houve correlações negativas significativas com o tempo de trabalho para a área da Fóvea (p=-051; p<0,05), e para os anéis de 30 (p=-0,46; p<0,05), 90 (p=-0,46; p<0,05) e 150 (p=-0,46; p<0,05). Não foi encontrada correlação significativa entre a sensibilidade ao contraste e o tempo de trabalho. Conclusões: Os resultados mostram alterações amplas e difusas no processamento visual em decorrência da exposição crônica a solventes orgânicos / Purpose: To evaluate the outcome of chronic occupational exposure to a mixture of solvents on the visual system of a group of gas station workers. Methods: 25 gas station workers (20 male; M=36,4 years old, SD=8,9) and 25 controls (10 male; M=33,8 years old, DP=8,8) with no history of chronic exposure to solvents were tested for hue discrimination and arrangement, spatial contrast sensitivity, visual field and multifocal VEPs. Urinary concentrations of toluene (M=0,3g/g of creatinine; Sd=0,16) and xylene metabolites (M=0,1 g/g creatinine; SD=0), along with the time of work (M=9,6 years; SD=6,2) were used as indicators of the exposure. The participants were submitted to an ophthalmologic examination and corrected the visual acuity to 20/20 whenever needed. All measurements were monocular (eye randomly chosen) and only one eye was tested, except for Multifocal Visual Evoked Potential (mfVEP) and the automated perimetry. Color was evaluated with the Lanthony D15d and Cambridge Colour Test 2.0. Automatic static perimetry used the white-on-white 24-2 protocol of the Humphrey Field Analyzer II-750i. Visual field was also evaluated with the mfVEP system Veris Science 5.2.4. Contrast sensitivity was measured with Metropsis software, using sine wave gratings of 0,2; 0,5; 1,0; 2,0; 5,0; 10,0 and 20,0 cpd. Results: The results for the two groups were compared using the Mann-Whitney U test. In the color discrimination test, the groups were significantly different for the thresholds in the three confusion axis tested (p<0,05), area of the ellipse (p<0,01) and ellipticity (p<0,05). In the color arrangement test, the two groups were significantly different (p<0,01). The automated perimetry results were also significantly different between groups for the 90, 150 e 210 eccentricity rings (p<0,05) and the MD and PSD values (p<0,05). Only three of the workers were tested with the mfVEP so far. All three had at least 30 sectors in the visual field 10 with significant loss of amplitude in the response (p<0,05, when compared to normative data). This result was not observed in the control group. The Spearman correlation coefficient was used to look for significant correlations between time of work and visual performance. For color vision, we found significant positive correlation between time of work and indexes of the Lanthony D15d (p=0,52; p<0,05) and deutan axis thresholds (p=0,59; p<0,05) for the CCT test. The analysis of sensitivity in eccentricity rings of perimetry data showed significant negative correlation with the time of work for the Fovea (p=-051; p<0,05) and rings of 30 (p=-0,46; p<0,05), 90 (p=-0,46; p<0,05) e 150 (p=-0,46; p<0,05). The contrast sensitivity data was not significantly correlated with time of work. Conclusions: The results presented here suggest that chronic occupational exposure to organic solvents leads to changes in the visual system function even when the exposure is within occupational safety limits. The results also suggest that the visual changes are extensive and diffuse

INTRODUÇÃO: O idoso freqüentemente apresenta alterações no Processamento Auditivo (Central), as quais contribuem para uma piora na qualidade de vida e afetam o relacionamento social destes indivíduos. O Treinamento Auditivo é uma prática amplamente utilizada na reabilitação de indivíduos com Transtorno de Processamento Auditivo (Central) e sua efetividade pode ser comprovada por meio de testes comportamentais e eletrofisiológicos. OBJETIVOS: Os objetivos deste estudo foram caracterizar o Processamento Auditivo (Central) em indivíduos idosos e verificar a efetividade do Treinamento Auditivo em idosos com Transtorno de Processamento Auditivo (Central). MÉTODOS: Participaram do estudo 15 indivíduos com Transtorno de Processamento Auditivo (Central) (Grupo Estudo) e 13 indivíduos sem Transtorno de Processamento Auditivo (Central) (Grupo Controle) com idades entre 60 e 79 anos. Todos os sujeitos realizaram uma avaliação inicial comportamental do Processamento Auditivo (Central) e uma primeira gravação do complexo N1-P2-N2 e do P300 (avaliação eletrofisiológica). O Grupo Estudo foi submetido a um programa de Treinamento Auditivo em cabine acústica durante oito sessões e, um mês após o término deste período foram realizadas novas avaliações comportamental e eletrofisiológica. O Grupo Controle foi submetido a um Treinamento Visual com duração de oito semanas, e, um mês após o término deste período, foi realizada nova avaliação eletrofisiológica. RESULTADOS: Na avaliação comportamental, houve diferença estatisticamente significante entre o Grupo Estudo e o Grupo Controle, e nas situações pré e pós Treinamento Auditivo no Grupo Estudo, nos testes Dicótico de Dígitos e Padrão de Freqüência. Quando comparados os dados eletrofisiológicos, não foram encontradas diferenças significantes na comparação entre os grupos na avaliação inicial e, após o Treinamento Auditivo e o Treinamento Visual, houve diferença estatisticamente significante entre os grupos nas latências de N1, P2 e N2. Na comparação do Grupo Estudo antes e após o Treinamento Auditivo, houve diferença estatisticamente significante para a latência de N2, e na comparação do Grupo Controle antes e após o Treinamento Visual, houve diferença significante na latência de P2 e na amplitude de N1P2. CONCLUSÕES: O Grupo Estudo, quando comparado ao Grupo Controle, apresentou pior desempenho na avaliação comportamental do Processamento Auditivo (Central), e ambos os grupos apresentaram respostas eletrofisiológicas similares antes do Treinamento Auditivo e do Treinamento Visual. O programa de Treinamento Auditivo foi eficaz na melhora do desempenho nas habilidades do Processamento Auditivo (Central) no Grupo Estudo, e esta melhora também pôde ser visualizada na diminuição da latência das ondas N1, P2 e N2 e no aumento da amplitude do P300 após o Treinamento Auditivo / INTRODUCTION: Elderly individuals usually present (Central) Auditory Processing Disorder which contribute for the deterioration of quality of life and affect the social relations of such individuals. The Auditory Training is a broadly used technique in the rehabilitation of individuals with (Central) Auditory Processing Disorder and its effectiveness may be evidenced by behavioral and electrophysiological tests. AIMS: This study aimed to characterize the (Central) Auditory Processing in elderly individuals and to verify the effectiveness of Auditory Training in elderly with (Central) Auditory Processing Disorder. METHODS: 15 individuals with (Central) Auditory Processing Disorder (Study Group) and 13 individuals without (Central) Auditory Processing Disorder (Control Group), ranging in age from 60 to 79 years old, took part in the study. All subjects underwent an initial behavioral assessment of (Central) Auditory Processing and a first recording of N1-P2- N2 complex and of P300 (electrophysiological assessment). The Study Group underwent an Auditory Training program in acoustic booth for eight sessions, and a month later new behavioral and electrophysiological assessments were performed. The Control Group underwent a Visual Training during eight weeks, and a month later a new electrophysiological assessment was performed. RESULTS: There was a significant statistical difference between the Study Group and the Control Group in the behavioral assessment and in the situations pre and post Auditory Training in the Study Group in Dichotic Digit and Frequency Pattern tests. Concerning the electrophysiological data, no significant differences were found between the groups in the initial assessment; after the Auditory and the Visual Training there was a significant statistical difference between the groups in the latency of N1, P2 and N2. Comparing the Study Group before and after the Auditory Training, there was a statistically significant difference for the latency of N2; and comparing the Control Group before and after the Visual Training, there was a significant difference for the latency of P2 and the amplitude of N1P2. CONCLUSIONS: The Study Group presented worse performance in the behavioral assessment of the (Central) Auditory Processing when compared to the Control Group, and both groups presented similar electrophysiological responses before the Auditory and the Visual Training. The Auditory Training improved the performance of (Central) Auditory Processing skills in the Study Group, and this improvement could also be verified in the latency decrease of waves N1, P2 and N2 and in the increase of P300 amplitude, after the Auditory Training

INTRODUÇÃO: O processamento temporal pode ser definido como a percepção das características temporais do som, ou a percepção na mudança da duração dessas características, dentro de um intervalo de tempo restrito. Para que essas sutis mudanças possam ser percebidas, o sistema nervoso auditivo central necessita de um processamento preciso da estrutura de tempo do sinal acústico recebido. Nesse estudo, os objetivos foram: avaliar a resolução temporal, por meio de dois diferentes testes, o GIN (gap-in-noise), um teste comportamental, e o Potencial evocado auditivo de estado estável, um teste eletrofisiológico, em indivíduos normais, com lesão neurológica, e com transtorno de processamento auditivo (central); e verificar a sensibilidade e a especificidade, de ambos os testes. MÉTODOS: Foram avaliados 70 indivíduos voluntários, de ambos os gêneros, com idade entre 16 e 50 anos, divididos em três grupos: G1(grupo normal), G2 (grupo com lesão de lobo temporal, causada por Esclerose mesial temporal), e G3 ( indivíduos com transtorno do processamento auditivo (central)). Todos os indivíduos realizaram ambos os testes. No teste GIN foram utilizadas as listas um e dois. Os limiares de detecção de gap e a porcentagem de acertos foram calculados para todos os indivíduos. O potencial evocado auditivo de estado estável foi realizado com modulação de freqüência de 46 Hz, nas intensidades de 500 e 2000 Hz, em ambas as orelhas. Foram calculados os limiares eletrofisiológicos, os limiares estimados, e a diferença entre o limiar tonal comportamental e o eletrofisiológico, para todos os indivíduos. RESULTADOS: Os resultados do teste GIN mostraram que os indivíduos do G2 apresentam limiares de detecção de gap significantemente piores que os indivíduos do G1 e do G3. O mesmo ocorreu para a porcentagem de acertos, o G2 apresentou uma porcentagem de acertos pior que os grupos G1 e G3. Os indivíduos do G3 apresentaram limiares de detecção de gap aumentados em relação ao G1, porém, sem diferença estatisticamente significante. O teste GIN apresentou uma boa especificidade em todos os grupos, e uma sensibilidade melhor para lesão neurológica do que para transtorno do processamento auditivo (central). Os resultados do potencial evocado auditivo de estado estável mostraram que o G2 apresentou limiares eletrofisiológicos e estimados significantemente piores que os encontrados no G1 e G3. A diferença entre o limiar eletrofisiológico e o comportamental no G2 foi maior que a obtida no G1 e no G3. Os resultados da especificidade e da sensibilidade foram semelhantes aos encontrados no GIN. Além disso, foi encontrada uma boa especificidade, e sensibilidade melhor para lesão neurológica que para transtorno do processamento auditivo. CONCLUSÕES: Os indivíduos com lesão de sistema nervoso auditivo central mostraram um maior comprometimento da habilidade de resolução temporal, avaliada no teste GIN e no potencial evocado auditivo de estado estável, que os indivíduos com disfunção do sistema nervoso auditivo central, e os indivíduos normais. Os valores de especificidade foram melhores que os valores de sensibilidade em ambos os testes, nos três grupos avaliados. A sensibilidade para lesão neurológica foi melhor que a sensibilidade para transtorno do processamento auditivo (central) em ambos os testes / INTRODUCTION: Temporal processing can be defined as a perception of temporal characteristics of the sound, or as a perception of the change in the duration of these characteristics, in a restrict period of time. For these subtle changes to be noticed, the central nervous system needs an accurate processing of the structure of the acoustic stimulus received. The aims of this study were: to assess the temporal resolution using two different tests - the gaps-in-noise test (a behavioral test) and the Auditory steady-state response (an electrophysiological test) in three groups of subjects: normal group; neurological group and (central) auditory processing disorder group. It also aimed to verify the sensitivity and specificity of the two tests. METHODS: Seventy volunteers of both genders were evaluated. Subjects ranged in age from 16 to 50 years, and were divided in three groups: G1 (normal group); G2 (subjects with temporal lobe insult caused by temporal mesial sclerosis) and G3 (subjects with (central) auditory processing disorder). Both tests were conducted on all subjects. The lists 1 and 2 of the gap-in-noise test were applied in all subjects. Gap detection threshold and the percentage of correct responses were calculated for all participants. Auditory steady-state response with 46 Hz of frequency modulation was applied for the frequencies of 500 Hz and 2000 Hz in both ears. Electrophysiological and estimated thresholds were calculated, and the difference between estimated and behavioral tonal thresholds was also obtained for the subjects. RESULTS: results of the gaps-in-noise test showed that the G2 gap detection thresholds were significantly worse than the G1 and G3 thresholds. The same result was observed for the percentage of correct responses, G2 showed a worse percentage of correct responses than those verified for the G1 and the G3 groups. Individuals of the G3 showed increased gap detection threshold compared with the G1, although this difference was not statistically significant. Gaps-in-noise test showed a good specificity for all groups, and a better sensitivity for the neurological lesions group than for the central auditory processing disorder group. Auditory steady-state response results suggested that G2 had electrophysiological and estimated thresholds significantly worse than G1 and G3. The difference between electrophysiological and behavioral threshold for G2 was bigger than the difference obtained in G1 and G3. Specificity and sensitivity results were similar to what was observed for the gaps-in-noise test results. Moreover, a good specificity was detected and the sensitivity showed better results for neurological lesions than for (central) auditory processing disorder. CONCLUSIONS: Individuals with central auditory nervous system lesions showed larger commitment of temporal resolution ability, evaluated through the gaps-innoise test and through the auditory steady state test, than normal individuals. Specificity values for all groups in both tests were better than sensitivity values. The sensitivity for the neurological lesion group was better than for the central auditory processing disorder group, for the two tests.

This present thesis is focused on the description of relation between brain activity while solving approximate arithmetic tasks and results in Stanford Binet's intelligence test in preschool children. The influence of N1, N2 and P2p components and late posterior components on non-symbolic numerical processing has been validated. Furthermore, it is the influence of maturation with each measured component and also the difference in their amplitude and their commencement after the stimulus presentation that must be pointed out. Our research data show that it is the very amplitude and its commencement that can be used as a potential intelligence indicator in preschool children. Both these components are related to cognitive processing time which has repeatedly proved to correlate with G intelligence factor. It is especially N2 component, which is connected with inhibitiory control of executive functions, that seems to have the potential for this diagnosis. Generally, it is P2p component that is given major attention. Nevertheless, in our research, this component has shown inconsistent results with respect to the amplitude which can be attributed to a low variance of our children's intelligence.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 98-112).

Kognityvieji sukeltieji potencialai arba su įvykiu susiję potencialai (SĮSP) leidžia įvertinti kai kurias kognityviąsias funkcijas. Jie nuo pat sukūrimo pradžios yra sėkmingai taikomi ir psichikos sutrikimų tyrimuose. SĮSP neinvaziškumas, objektyvumas, saugumas leidžia juos taikyti kognityviųjų funkcijų pokyčių, sukeltų medikamentinio gydymo ar kitos nemedikamentinės terapinės procedūros, įvertinimui. Pagrindinis darbo tikslas buvo įvertinti informacijos apdorojimo klausos sistemoje kitimą atipinių antipsichotikų risperidono ir kvetiapino poveikyje ir nemedikamentinių terapijos metodų - elektros impulsų terapijos bei metaglosoterapijos - poveikyje taikant su įvykiu susijusio potencialo P300 skaitmeninio registravimo ir kiekybinės analizės metodus. Klausos sukeltas P300 potencialas buvo registruojamas taikant „atsitiktinio įvykio“ principą trimis elektrodais (Fz, Cz ir Pz). Buvo matuojami 4 sukeltojo potencialo P300 parametrai: N2 latencija, P300 latencija, P300 amplitudė ir reikšmingo dirgiklio atpažinimo laikas. Darbo rezultatai parodė, kad SĮSP parametrai yra jautrūs informacijos apdorojimo klausos sistemoje procesų pažeidimo šizofrenijos spektro sutrikimų atveju rodikliai. Didesnę teigiamą įtaką klausos sukeltajam potencialui P300 turėjo atipinis antipsichotikas kvetiapinas. Nemedikamentiniai psichikos sutrikimų gydymo metodai nenusileidžia efektyvumu gerinant pacientų kognityviąsias funkcijas medikamentinei terapijai atipiniais antipsichotikais. / Recording and analysis of event-related potentials is safe and harmless method of evaluation of cognition and is suitable to follow the changes of cognitive processes induced by psychoactive drugs or other therapeutic procedures. The main aim of the work was to evaluate the influence of atypical antipsychotics risperidone and quetiapine and such nonpharmacological methods as electroconvulsive therapy and metaglossotherapy on the changes of information processing in the auditory system using event-related potential P300 recording and analysis method. Auditory P300 potential was elicited applying “odd-ball” paradigm and recorded at 3 electrode sites (Fz, Cz, Pz). 4 parameters of P300 potential were measured: N2 latency, P300 latency, P300 amplitude and recognition time of target stimulus. Total number of 85 patients with schizophrenia spectrum disorders and mood disorders were studied. Results of this work showed that the parameters of P300 potential are sensitive indicators of abnormalities of information processing in auditory system in the case of schizophrenia spectrum disorders. More considerable positive influence on the event-related potential P300 had atypical antipsychotic quetiapine and that nonpharmacological methods of treatment of psychiatric disorders are as effective as drug therapy with atypical antipsychotics in remediation of cognitive functions.

Recording and analysis of event-related potentials is safe and harmless method of evaluation of cognition and is suitable to follow the changes of cognitive processes induced by psychoactive drugs or other therapeutic procedures. The main aim of the work was to evaluate the influence of atypical antipsychotics risperidone and quetiapine and such nonpharmacological methods as electroconvulsive therapy and metaglossotherapy on the changes of information processing in the auditory system using event-related potential P300 recording and analysis method. Auditory P300 potential was elicited applying “odd-ball” paradigm and recorded at 3 electrode sites (Fz, Cz, Pz). 4 parameters of P300 potential were measured: N2 latency, P300 latency, P300 amplitude and recognition time of target stimulus. Total number of 85 patients with schizophrenia spectrum disorders and mood disorders were studied. Results of this work showed that the parameters of P300 potential are sensitive indicators of abnormalities of information processing in auditory system in the case of schizophrenia spectrum disorders. More considerable positive influence on the event-related potential P300 had atypical antipsychotic quetiapine and that nonpharmacological methods of treatment of psychiatric disorders are as effective as drug therapy with atypical antipsychotics in remediation of cognitive functions. / Kognityvieji sukeltieji potencialai arba su įvykiu susiję potencialai (SĮSP) leidžia įvertinti kai kurias kognityviąsias funkcijas. Jie nuo pat sukūrimo pradžios yra sėkmingai taikomi ir psichikos sutrikimų tyrimuose. SĮSP neinvaziškumas, objektyvumas, saugumas leidžia juos taikyti kognityviųjų funkcijų pokyčių, sukeltų medikamentinio gydymo ar kitos nemedikamentinės terapinės procedūros, įvertinimui. Pagrindinis darbo tikslas buvo įvertinti informacijos apdorojimo klausos sistemoje kitimą atipinių antipsichotikų risperidono ir kvetiapino poveikyje ir nemedikamentinių terapijos metodų - elektros impulsų terapijos bei metaglosoterapijos - poveikyje taikant su įvykiu susijusio potencialo P300 skaitmeninio registravimo ir kiekybinės analizės metodus. Klausos sukeltas P300 potencialas buvo registruojamas taikant „atsitiktinio įvykio“ principą trimis elektrodais (Fz, Cz ir Pz). Buvo matuojami 4 sukeltojo potencialo P300 parametrai: N2 latencija, P300 latencija, P300 amplitudė ir reikšmingo dirgiklio atpažinimo laikas. Darbo rezultatai parodė, kad SĮSP parametrai yra jautrūs informacijos apdorojimo klausos sistemoje procesų pažeidimo šizofrenijos spektro sutrikimų atveju rodikliai. Didesnę teigiamą įtaką klausos sukeltajam potencialui P300 turėjo atipinis antipsichotikas kvetiapinas. Nemedikamentiniai psichikos sutrikimų gydymo metodai nenusileidžia efektyvumu gerinant pacientų kognityviąsias funkcijas medikamentinei terapijai atipiniais antipsichotikais.

The notion that learning and memory processes are highly dependent on central cholinergic neurotransmission has been widely accepted. However, studies documenting the importance of Acetylcholine (ACh) in attention have led some to suggest that attention impairments may underlie the deficits in learning and memory resulting from cholinergic disruptions. Using a visual discrimination task, I attempted to discern whether performance impairments by Scopolamine were predominantly due to the importance of muscarinic receptor integrity in attention, or memory consolidation in learning. Rats were trained in a visual discrimination task using a Y-shaped water maze apparatus. To successfully navigate to a hidden platform located in one of the two goal arms, rats learned to discriminate between 2 distinct visual cues, indicating the platform’s presence (CS+) or absence (CS-), respectively. Following task acquisition, testing continued using a combination of Regular trials (RT; both CS+ and CS- present) and Probe trials (PT; only one of the cues present). Results indicated that performance on PT was impaired due to greater task difficulty under conditions of reduced information, while Scopolamine (1 mg/kg) further impacted PT performance without affecting RTs. In a second experiment, PTs were administered with the platform present to provide reinforcement and a learning opportunity. Animals still exhibited poorer PT performance, but rapidly learned to rely on a single cue for accurate platform localization. Interestingly, this learning was not apparent under conditions of Scopolamine treatment (1 mg/kg), even though RT performance was completely unaffected. To examine experience-dependent changes in neuronal responding after visual discrimination learning, a subset of animals were anesthetised and visual evoked potentials (VEPs) in V1 and area CA1 of the hippocampus were recorded in response to CS+, CS-, and novel stimuli. In both the V1 and CA1, the VEP amplitudes elicited to familiar and novel stimuli were not significantly different. First, these experiments demonstrate the importance of the cholinergic system in sustaining visual attention and acquiring a new single-cue strategy. Furthermore, the null electrophysiology findings do not rule out the plastic response properties of the mature V1 and CA1, but remind us of the complex nature of memory encoding in the brain. / Thesis (Master, Psychology) -- Queen's University, 2011-09-16 13:50:24.045