Participants

Two groups of children aged between 7 and 11, matched on chronological age, level of formal education, and IQ level (see Table 1), took part in this study. The first one consisted of 40 children with high-functioning ASD recruited at Bambino Gesù Children’s Hospital in Rome, Italy. The Raven’s Coloured Progressive Matrices [(Raven, 1938); Italian standardization: Belacchi et al., 2008] were employed to assess their IQ, which turned out to be within the normal range. The diagnosis of ASD was established by the neuropsychologists of Bambino Gesù Children’s Hospital and was based on clinical observation in compliance with the Diagnostic and Statistical Manual of Mental Disorders-V criteria [DSM-5 American Psychiatric Association (APA), 2013]. The severity of autistic symptomatology was ascertained through the administration of the Autism Diagnostic Observation Schedule 2nd edition – ADOS-2 by Lord et al. (2013). Overall, the group of participants with ASD had a mean severity score of 5.90 with a standard deviation of 1.42 ranging from 3 to 8.

General data of the two groups of participants.

Forty children with typical development (TD) formed the control group. TD children obtained scores within the normal range on the Raven’s Progressive Matrices (Raven, 1938; Italian standardization: Belacchi et al., 2008) aimed at assessing their levels of nonverbal intelligence. In a preliminary interview, their teachers confirmed that they had normal cognitive development, as well as average school performance. According to school records and parents’ reports, none of them had a known history of psychiatric or neurological disorders, learning disabilities, hearing or visual loss.

In order to obtain a general cognitive profile of the two groups, both children with ASD and TD were administered tasks assessing their verbal short-term and working memory, namely the Non-Word Repetition subtest of the Prove di Memoria e Apprendimento per l’Età Evolutiva (PROMEA, Vicari, 2007) and the Forward and Backward Digit Span’s subtests of the Wechsler Scales (Wechsler, 1993).

The Bambino Gesù Children’s Hospital committee approved this study. Parents signed the consent form for the participation of their children to the study and for the treatment of the data.