title: Discrepancy of performance among working memory-related tasks in autism spectrum disorders was caused by task characteristics, apart from working memory, which could interfere with task execution.
abstract: Working memory performance has been inconsistently reported in autism spectrum disorders (ASD). Several studies in ASD have found normal performance in digit span and poor performance in digit symbol task although these are closely related with working memory. It is assumed that poor performance in digit symbol could be explained by confirmatory behavior, which is induced due to the vague memory representation of number-symbol association. Therefore it was hypothesized that the performance of working memory task, in which vagueness did not cause confirmatory behavior, would be normal in ASD. For this purpose, the Advanced Trail Making Test (ATMT) was used. The performance of digit span, digit symbol and ATMT was compared between ASD and normal control. The digit span, digit symbol and ATMT was given to 16 ASD subjects and 28 IQ-, age- and sex-matched control subjects. The scores of these tasks were compared. A significantly lower score for ASD was found only in digit symbol compared with control subjects. There were no significant difference in digit span and working memory estimated by ATMT. Discrepancy of scores among working memory-related tasks was demonstrated in ASD. Poor digit symbol performance, normal digit span and normal working memory in ATMT implied that ASD subjects would be intact in working memory itself, and that superficial working memory dysfunction might be observed due to confirmatory behavior in digit symbol. Therefore, to evaluate working memory in ASD, tasks that could stimulate psychopathology specific to ASD should be avoided.
authors.affiliation: Department of Clinical Neuroscience, Osaka University Graduate School of Medicine, Osaka Second Police Hospital, Suita, Osaka, Japan. nakaha@psy.med.osaka-u.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakahachi
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Eiko
authors.initials: E
authors.lastname: Honaga
authors.forename: Ryuji
authors.initials: R
authors.lastname: Sekiyama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ukai
authors.forename: Ryouhei
authors.initials: R
authors.lastname: Ishii
authors.forename: Wataru
authors.initials: W
authors.lastname: Ishigami
authors.forename: Osami
authors.initials: O
authors.lastname: Kajimoto
authors.forename: Ko
authors.initials: K
authors.lastname: Yamashita
authors.forename: Ryota
authors.initials: R
authors.lastname: Hashimoto
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tanii
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
mesh_terms: D000328:Adult; D020817:Asperger Syndrome / Q000523:psychology*; D001288:Attention; D001321:Autistic Disorder / Q000523:psychology*; D016022:Case-Control Studies; D003071:Cognition; D003201:Computers; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008570:Memory, Short-Term; D011597:Psychomotor Performance; D013647:Task Performance and Analysis; D014145:Trail Making Test; D014888:Wechsler Scales