Working Memory Deficits and its Relationship to Autism Spectrum Disorders.

BACKGROUND: There is a wealth of research done in developed countries on the investigation of the working memory (WM) performance in people with high-functioning Autism Spectrum Disorders (ASD) (IQ>70), with different reported findings. There is a dearth of similar studies in developing countries. In addition, the findings suggest that WM is possibly influenced by culture. The present study investigated WM performance and its relationship with the symptoms of ASD and Attention Deficit Hyperactivity Disorder (ADHD). METHODS: The present study is a cross-sectional comparative study between two groups of participants with high-functioning ASD, aged 8-16 years (n=30) and typically developing (n=30). This study was conducted in 2016-2017 in Tehran (Iran). The Multivariate Analyses of Variance (MANOVA) was used to compare the between-group differences on WM tasks. In addition, Pearson's correlation coefficient was used to examine the relationship between the ASD and ADHD symptoms with WM performance. The data were statistically analyzed using the Statistical Package for the Social Sciences (SPSS), version 16. RESULTS: It was found that in general, WM was impaired in the people with ASD. Unexpectedly, in the present study, two subscales of Social interaction and Stereotyped Behaviors of the Gilliam Autism Rating Scale-Second Edition showed a significant positive correlation respectively with a score of two WM tasks, i.e. Visual Digit Span and Digit Span Forward. CONCLUSION: These results showed that WM was impaired in individuals with ASD and that could have implications for intervention, but it is necessary that therapists be careful in choosing the appropriate tasks for intervention.

The Cognitive Profile of People with High-Functioning Autism Spectrum Disorders.

Several studies have examined the cognitive profile of people with high-functioning autism spectrum disorders (ASD) (IQ > 70), and its relationship with the symptoms of ASD and attention deficit hyperactivity disorder (ADHD), using the Wechsler Intelligence Scale for Children-IV (WISC-IV). However, no data exist on the similarities or differences in this profile in less affluent countries. The present study examined the cognitive profile and its relationship with the symptoms of ASD and ADHD in 30 subjects aged 6⁻16 years with high-functioning ASD and compared the results with those of 30 typically developing (TD) subjects. In line with previous research findings, the WISC-IV cognitive profile analysis of subjects with high-functioning ASD showed a good competence in Matrix Reasoning and weaknesses in Comprehension, but the main distinguishing point was the competence in processing speed in both groups. In the present study, the Verbal Comprehension Index correlated negatively with the communication symptoms, and the Working Memory Index correlated positively with the social symptoms in the ASD group. Given the similarities that exist between the results of the present research and previous studies, it may be concluded that there are similarities in the cognitive profile of individuals with ASD.

Impaired nonverbal working memory in high-functioning autism spectrum disorder.

Background: Past studies have documented working memory impairment in participants with high-functioning Autism Spectrum Disorders (IQ>70), but inconsistent findings have been reported. One possibility is the existence of verbal responses in the evaluation of working memory performance. The aim of the current study is to examine the working memory performance and its correlation with a prominent deficit in participants with high-functioning Autism Spectrum Disorders by non-verbal working memory tasks compared with typically developing samples. Methods: The current study is a cross-sectional, comparative study. The working memory performance of the 30 participants with high-functioning Autism Spectrum Disorders (7-16 years) and 30 typically developing was compared by working memory subtests of the Leiter International Performance Scale-Revised in Tehran, Iran. Two groups were matched for age and gender. ANOVA, ANCOVA, repeated measures ANOVA and Pearson's correlation coefficient were used to analyze the data statistically. The significance value was set at p<0.05. Results: The results showed that if the effect of FSIQ (full-scale intelligence quotient) were controlled individuals with highfunctioning Autism Spectrum Disorders exhibited significant impairment in the Reverse Memory subtest (p=0.001). Also, unpredictably Forward Memory (r=0.38, p=0.03) and Reverse Memory tasks (r=0.38, p=0.03) displayed a significant positive correlation with the Social interaction subscale of the Gilliam Autism Rating Scale (Second Edition). Conclusion: It seems that nonverbal working memory is impaired in persons with high-functioning Autism Spectrum Disorders. Results of the current study revealed that factors like complexity and cognitive load of tasks may influence working memory performance in individuals with high-functioning Autism Spectrum Disorders.