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Previous issue date: 2016-05-24 / As emo??es influenciam no comportamento, contribuindo para a adapta??o ao ambiente, e modulando os processos cognitivos como a percep??o, a aten??o e a mem?ria. As imagens com conte?do emocional afetam o potencial evocado visual, provocando aumento nas amplitudes dos componentes precoces. Por?m, ainda n?o ? claro como o conte?do emocional associado a uma determinada via sensorial pode afetar o processamento de outras modalidades sensoriais. O objetivo deste estudo foi avaliar como as imagens com conte?do emocional influenciam o processamento sensorial auditivo, atrav?s do potencial evocado auditivo de um som in?cuo. Para isso, foi registrado o potencial evocado auditivo em 36 estudantes universit?rios durante a apresenta??o de blocos de imagens negativas, blocos de imagens positivas, blocos de imagens neutras ou uma tela em branco. Analisamos tamb?m os escores de val?ncia e alerta das imagens, a variabilidade da frequ?ncia card?aca e a pot?ncia das bandas de frequ?ncia teta e alfa,. As imagens negativas, positivas e neutras tiveram os escores de val?ncia e alerta esperado para esses tipos de imagens, mas esses resultados diferiram dos escores da padroniza??o realizada para o Brasil. J? na variabilidade da frequ?ncia card?aca, foi observada uma desacelera??o do ritmo card?aco durante a apresenta??o das imagens negativas e positivas, o que correlacionou com os escores das imagens. Quanto ao potencial evocado auditivo, n?o encontramos um efeito da emo??o. Contudo, foi encontrada uma diminui??o da amplitude do potencial evocado durante a apresenta??o das imagens, independentemente da sua val?ncia. As an?lises das bandas de frequ?ncias mostraram um aumento da pot?ncia de teta e alfa no hemisf?rio esquerdo inicialmente durante as quatro condi??es. Em um segundo momento foi observado um aumento da pot?ncia dessas bandas durante a apresenta??o das imagens emocionais no hemisf?rio direito. Por ?ltimo, foi observada uma diminui??o da pot?ncia de teta no hemisf?rio direito na condi??o de imagens negativas. Os resultados da avalia??o das imagens e a variabilidade da frequ?ncia verificam que as imagens do International Affective Picture System (IAPS) s?o um bom m?todo para induzir e avaliar emo??es. Contudo, ? importante fazer uma melhor padroniza??o para todo o Brasil. A resposta do potencial evocado indica uma divis?o da orienta??o da aten??o entre as duas fontes de estimula??o. Por fim, o incremento da pot?ncia de teta e alfa principalmente no hemisf?rio direito, evid?ncia a import?ncia do hemisf?rio direito no processamento de informa??o sensorial. / Emotions are crucial for the survivor of the organisms. They allow individuals to recognize what is threatening and what is safe in the environment. Emotions work modulating several cognitive processes, such as perception, attention and memory. At an electrophysiological level, emotions influence the response of neuronal networks measured by Event-Related Potentials (ERP). It has been documented that pleasant and unpleasant pictures increase the amplitude of the visual ERP in the visual areas of the brain. However, little is known about how emotions affect the processing of stimuli of different sensory modalities. The aim of this work was to test how the International Affective Picture System (IAPS) may affect the ERP of an innocuous sound. For this purpose the auditory ERP of 36 healthy students was recorded while they were watching a stream of high arousal unpleasant, high arousal pleasant, neutral images or a white screen. Heart rate variability (HRV), subjective self-report and band frequency power were measured too. Results showed that subjective self-report of the pictures emotional property verified the emotional qualities of these pictures, but it was slightly different form the Brazilian standard scores. We also found a deceleration of the HRV during emotional pictures viewing, and this correlated with the subjective self-report. No effect from emotional valence on the auditory ERP was found, only an effect of the pictures when compared to the white screen condition. In the left hemisphere, band frequency power showed a increase of theta and alpha power in the first moment for the four conditions. In a second moment, there was a increase of the power of this two bands during emotional pictures presentation in the right hemisphere. And then, it was seen a decrease in the right hemisphere of theta band power during unpleasant picture viewing. Scores from the subjective self-report and HRV confirmed that IAPS are a good method to elicit and evaluate emotions, but is necessary to extend the Brazilian standardization to have a more reliable instrument. Findings in the auditory ERP suggest a division of attention between the two kind of stimulation. Finally, the increase in the theta and alpha band power, especially in the right hemisphere, throughout the temporal series suggest a specialization of right hemisphere in the processing of emotional information.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/21899 |
| Date | 24 May 2016 |
| Creators | Hern?ndez, Laura Carolina Ahumada |
| Contributors | 22800662387, Andrade, Katia Cristine, 87652110300, Alves, Nelson Torro, 25060820858, Ara?jo, John Fontenele |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM PSICOBIOLOGIA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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