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Efeito do contexto semântico na memória de trabalho visual em indivíduos com perturbações do expectro do autismo de alto desempenho : não há cegueira contextual
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Resumo(s)
Diversas pesquisas sugerem défices na memória semântica em indivíduos com Perturbações
do Espectro do Autismo ‐ PEA (Toichi, 2008; Toichi e Kamio, 2003). É referido também que
pessoas com PEA apresentam dificuldades no processamento contextual (Loth, Gomez e Happé,
2008; 2011). Não parecem, pois, obter vantagens da informação contextual disponível, sendo a
cegueira contextual sugerida como substancial às anomalias na cognição deste grupo clínico
(Vermeulen, 2012) e consistente com a proposta de fraca coerência central nesta população
(Frith, 1997; Happé,1997; Happé e Frith, 2006).
Também, estudos indicam a existência de défices executivos em pessoas com PEA (Ozonoff,
Strayer e Filloux, 1994; Lopez, Lincoln, Ozonoff e Lai, 2005; Landa e Goldberg, 2005), sobretudo
um característico funcionamento da memória de trabalho com alguns aspetos preservados e
outros impedidos (Steele, Minshew e Sweeney, 2007; Williams,Goldstein, Carpenter e Minshew,
2005). São destacados prejuízos na memória de trabalho espacial, sendo a memória de trabalho
verbal intacta nessa população clínica (Williams et al., 2005). Expostos a tarefas visuais em
memória de trabalho, indivíduos com PEA não demonstraram vantagens ao lidar com
informação semântica na recordação imediata quando comparados aos indivíduos típicos
(Joseph, Steele, Meyer e Tager‐Flusberg, 2005; Mammarella,Giofrè, Caviola, Cornoldi e
Hamilton, 2014).
Entretanto, a ideia de que este grupo clínico não apresente benefícios do efeito do contexto
no processamento visual, apesar de bastante difundida, não é consensual (e.g. Van Eylen, De
Graef, Steyaert, Wagemans e Noens, 2013). Este estudo propôs‐se a averiguar a hipótese de
ausência do efeito do contexto no processamento visual da população com PEA. Investigou para
este propósito as relações entre memória semântica e memória de trabalho visual, através do
efeito da componente semântica de congruência ao contexto na recordação imediata de
indivíduos com PEA de Alto Desempenho. Aplicou‐se uma tarefa de memória de trabalho visual,
manipulada por condições de congruência semântica (congruente versus incongruente)
utilizando cenários e objetos reais. O efeito do contexto foi explicitado na tarefa através das
relações de expectativas do objeto ser encontrado no cenário, as quais podem influenciar a
recordação. Consoante à hipótese inicial, os resultados sugeriram um atraso no processamento
da memória de trabalho visual dos indivíduos com PEA,sobretudo com manipulação contextual.
Ainda, o efeito do contexto foi evidenciado na população com PEA de alto desempenho, sendo
mais robusto do que em indivíduos típicos. Os resultados foram debatidos em contraposição à
hipótese da cegueira contextual, contrastando com estudos anteriores. Assim, sugeriu‐se que o
contexto semântico influencia o processamento visual, com possíveis contributos à orientação
da atenção e favorecimento da recordação.
Several studies suggest semantic memory deficits in individuals with Autism Spectrum Disorders – ASD (Toichi, 2008; Tochi and Kamio, 2003). It is said also that people with ASD have difficulty in contextual processing (Loth, Gomez and Happe, 2008; 2011). They seem, therefore, do not take advantage of contextual information available, with contextual blindness been suggested as substantial to anomalies in cognition of this clinical group (Vermeulen, 2012) and in accordance with the proposal of weak central coherence in this population (Frith, 1997; Happé, 1997; Happé and Frith, 2006). Moreover, studies indicate the existence of executive deficits in people with ASD (Ozonoff, Strayer e Filloux, 1994; Lopez, Lincoln, Ozonoff e Lai, 2005; Landa e Goldberg, 2005), particularly an abnormal working memory functioning with some aspects preserved and others spared (Steele, Minshew and Sweeney, 2007; Williams, Goldstein, Carpenter and Minshew, 2005). Impairments in spatial working memory were detected, being the verbal working memory intact in this clinical population (Williams et al., 2005). Exposed to working memory visual tasks, individuals with ASD showed no advantages when dealing with semantic information in immediate recall compared to typical individuals (Joseph, Steele, Meyer e Tager‐Flusberg, 2005; Mammarella, Giofrè, Caviola, Cornoldi e Hamilton, 2014). The idea, however, that this clinical group does not present benefits of the context effect on visual processing, though widespread, is not consensual (eg Van Eylen, De Graef, Steyaert, Wagemans and Noens, 2013). This study aimed to investigate the hypothesis of the absence of the effect of context on visual processing in the population with ASD. For this purpose, I investigated the relationship between semantic memory and visual working memory, through the effect of the semantic component of contextual congruency in immediate recall of highfunctioning individuals with ASD. It was applied to a visual working memory task, with a semantic congruency manipulation (congruent versus incongruent) using real scenes and objects.The effect of context was explained in the task by the relations of expectations that an object will be encountered in the scenario, which can influence the recall. Congruent with initial hypothesis, the results suggested a delay in the processing of visual working memory in ASD, especially with contextual manipulation. The contextual effect was demonstrated in the sample of individuals with ASD with a high performance, being more robust than in typical subjects. The results were discussed as opposed to the hypothesis of contextual blindness, in contrast to previous studies. Thus, it was suggested that the semantic context influences visual processing, with possible contributions to the orientation of attention and memory favoring.
Several studies suggest semantic memory deficits in individuals with Autism Spectrum Disorders – ASD (Toichi, 2008; Tochi and Kamio, 2003). It is said also that people with ASD have difficulty in contextual processing (Loth, Gomez and Happe, 2008; 2011). They seem, therefore, do not take advantage of contextual information available, with contextual blindness been suggested as substantial to anomalies in cognition of this clinical group (Vermeulen, 2012) and in accordance with the proposal of weak central coherence in this population (Frith, 1997; Happé, 1997; Happé and Frith, 2006). Moreover, studies indicate the existence of executive deficits in people with ASD (Ozonoff, Strayer e Filloux, 1994; Lopez, Lincoln, Ozonoff e Lai, 2005; Landa e Goldberg, 2005), particularly an abnormal working memory functioning with some aspects preserved and others spared (Steele, Minshew and Sweeney, 2007; Williams, Goldstein, Carpenter and Minshew, 2005). Impairments in spatial working memory were detected, being the verbal working memory intact in this clinical population (Williams et al., 2005). Exposed to working memory visual tasks, individuals with ASD showed no advantages when dealing with semantic information in immediate recall compared to typical individuals (Joseph, Steele, Meyer e Tager‐Flusberg, 2005; Mammarella, Giofrè, Caviola, Cornoldi e Hamilton, 2014). The idea, however, that this clinical group does not present benefits of the context effect on visual processing, though widespread, is not consensual (eg Van Eylen, De Graef, Steyaert, Wagemans and Noens, 2013). This study aimed to investigate the hypothesis of the absence of the effect of context on visual processing in the population with ASD. For this purpose, I investigated the relationship between semantic memory and visual working memory, through the effect of the semantic component of contextual congruency in immediate recall of highfunctioning individuals with ASD. It was applied to a visual working memory task, with a semantic congruency manipulation (congruent versus incongruent) using real scenes and objects.The effect of context was explained in the task by the relations of expectations that an object will be encountered in the scenario, which can influence the recall. Congruent with initial hypothesis, the results suggested a delay in the processing of visual working memory in ASD, especially with contextual manipulation. The contextual effect was demonstrated in the sample of individuals with ASD with a high performance, being more robust than in typical subjects. The results were discussed as opposed to the hypothesis of contextual blindness, in contrast to previous studies. Thus, it was suggested that the semantic context influences visual processing, with possible contributions to the orientation of attention and memory favoring.
Descrição
Dissertação de mestrado, Ciência Cognitiva, Universidade de Lisboa, Faculdade de Ciências, Faculdade de Letras, Faculdade de Medicina, Faculdade de Psicologia, 2015
Palavras-chave
Autismo Memória semântica Memória visual Teses de mestrado - 2015