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Autism is a variation of neural development diagnosed as impaired social interaction and communication, and by restricted and repetitive behavior. It affects an estimated 10 in 1000 people. Autism is one of three recognized variations in the autism spectrum (ASDs), the other two being Asperger syndrome, which lacks delays in cognitive development and language, and pervasive developmental disorder, not otherwise specified (PDD-NOS), which is diagnosed when the full set of criteria for autism or Asperger syndrome are not met. In this article, the word ''autism'' is used for referring to the whole range of variations on the autism spectrum, which is not uncommon. Working memory is the system that actively holds multiple pieces of transitory information in the mind, where they can be manipulated. This system has a limited capacity. Working memory is a part of the executive functions (EF), an umbrella term for cognitive processes that regulate, control, and manage other cognitive processes, for instance planning and attention. A majority of the research has found that individuals with autism perform poorly on measures of executive function. A general decrease in working memory (WM) is one of the limitations, although some studies have found that working memory is not impaired in autistic children relative to controls matched for IQ. However, some evidence suggests that there may be minimal impairment in high-functioning autistic (HFA) individuals in that they have intact associative learning ability, verbal working memory, and recognition memory. In rare cases there are even instances of individuals possessing extremely good memory in constricted domains which are typically characterized as savants. Bennetto, Pennington and Rogers also suggest that WM deficits and limited EF is likely compounded by the onset of autism where early development yields hindrances in social interaction which typically (i.e. without impairment) improves both WM and EF. However, due to limited ability in interpreting social gestures and an impaired ability to process such information in a holistic and comprehensive manner, individuals with autism are subject to diminished and confounding instances of memory function and performance.〔 == Physiological underpinnings == The physical underpinnings of the cause for differences in the working memory of autistic people has been studied. Bachevalier suggests a major dysfunction in the brain of an autistic individual resides in the neural mechanisms of the structures in the medial temporal lobe (MTL) and perhaps, more specifically the amygdaloid complex. This may have implications in their ability to encode information because of the role the MTL and especially the hippocampal areas play in information processing DeLong reinforces this by suggesting autism to have an impact on hippocampal function. Because the hippocampus is pivotal in memory encoding and modulating memory consolidation, any impairment can drastically impact an autistic individual's ability to process (i.e. multi-modal) and retain information. Sumiyoshi, Kawakubo, Suga, Sumiyoshi and Kasai have suggested that it is possible that the attenuated neural activities in parahippocampal regions might have something to do with the abnormal organization of information of individuals within the autistic spectrum. The left parahippocampal region (including the parahippocampal gyrus) has an implied role in sorting, relating, and sending information to the hippocampus and thus any abnormal activity or dysfunction within these regions might be accountable for the degree of effectiveness autistic individuals organize information. This is in keeping with other findings that suggest unconventional activity or lack of activity within the hippocampal regions which have a role in explaining some aspects of ASD. Further evidence suggests that there is abnormal circuitry in what Brothers calls the neural basis for social intelligence, or holistically interpreting people's expressions and intentions. The interaction between the amygdala, the orbitofrontal cortex (OFC), and the superior temporal sulcus and gyrus (STG) enables one to process social information for personal interaction. In the case of autistic individuals there seems to be a limitation in these structures such that facial expressions, body language and speech expressions (ex. sarcasm) go consciously unnoticed. However, Frith and Hill suggest that through 'remediation' or training that attends to specific traits in expressions, social understanding can be partially improved. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Autism and working memory」の詳細全文を読む スポンサード リンク
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