DONAMATCH (2014) Candidato: D. Bonilla

Studies have revealed inconsistent findings regarding the relationship between shifting and social communication and interaction. A handful of studies have

indicated that shifting is neither correlated with social communication in children with ASD (Yerys, Wallace, Harrusin, Caelano, Giedd, & Kenworthy, 2009) nor with adolescents and young adults with ASD (Teunisse et al., 2001). Yerys et al., (2009) indicated that there is no significant correlation between shifting and social

communication in a group of 35 high-functioning children aged 6- and 13-year-old by using Intradimensional /Extradimensional (ID/ED) shift test. In another study, Reed, Watts and Truzoli (2013) did not find a significant correlation between shifting and social communication and communication difficulties in a group of 15 low-

functioning autistic children whose mean age was 8 years old and mean nonverbal IQ was 71. Similarly, Teunisse et al., (2001) suggested that shifting is not correlated with social competence in a sample of 35 high-functioning people who are aged from 16 to 24 years old, by using several laboratory tasks including a Wisconsin card sorting task.

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However, Berger, Aerts, Spaendonck, Cools, & Teunisse (2003) suggested that shifting was a prognostic marker on social functioning including symptom severity, social intelligence and social competence after a 3-year period pre-test and post-test.

In terms of repetitive behaviours and interests, several studies have suggested links between shifting and repetitive behaviours. Brunsdon and Happé (2014)

suggested that shifting deficits underlie restricted and repetitive behaviours and interests (RRBI) in ASD because of the failure to shift mental sets. Turner (1997) hypothesised that difficulties in shifting between two ongoing tasks underpin the RRBI seen in ASD. Yerys et al., (2009) reported shifting ability has a significant and positive correlation with RRB in 35 children with autism aged 6 to 13 years old using ED reversal shifting score in ID/ED task but not during ED shifting stage. Similarly, South, Ozonoff and Mcmahon (2007) found that perseverative errors on Wisconsin card sorting task of shifting was significantly correlated with repetitive behaviour in a sample of 19 adolescents with high-functioning autism aged 10 to 19 years. These studies suggested that laboratory shifting task underlying repetitive behaviours and interests in ASD. Also, D’Cruz, Ragozzino, Mosconi, Shrestha, Cook and Sweeney (2013) examined 41 adolescents with ASD aged 15 years old using a probabilistic reversal learning task. This required the participants to choose the picture which was in the correct location by following the criterion. After the first stage, participants had to adapt to a new reversal criterion and immediate feedback was provided. The regressive errors which were assessing how well participants could maintain the new criterion, were found to be significantly correlated with RRBI (Repetitive Behaviours Scale-Revised, (RBS-R; Bodfish, Symons, Parker, & Lewis, 2000).

The association between shifting and increased severity of RRBI has been found by Miller et al., (2015) using ADOS and ADI-R. Shifting was assessed by a card-sorting paradigm test, Penn Conditional Exclusion test (PCEF; Kurtz, Ragland, Moberg, & Gur, 2004). Total error rates were found to be significantly related to RRB in a group of 60 adolescents with ASD aged 15 years.

The relationship between shifting and RRBI has also been supported in further research extended to a low-functioning autism group (Reed, Watts, & Truzoli, 2011)

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and to an adult autism group (Lopez, Lincoln, Ozonoff, & Lai, 2005). Reed et al., (2011) have examined children aged 8 with conditioning materials, which was assessing shifting ability. Significant correlations were found between several perseverative errors within shifting task and stereotyped behaviours. Lopez et al., (2005) have found that in adults with autism spectrum disorder, there was a positive relationship between shifting and restricted and repetitive behaviours. In the further examination of a multiple regression model, shifting was the sole executive deficit to predict restrictive and repetitive symptoms. However, when shifting, working

memory and inhibition were entered into the same regression model, none of the cognitive abilities predict the restricted and repetitive behaviours.

There have therefore been several studies which have suggested that shifting is associated with RRBI in all of the participants’ samples, including high-functioning autistic children, low-functioning autistic children and adults.

5.7 Verbal fluency

Verbal fluency is the ability to generate a series of novel responses (see Chapter 1), which requires successful information retrieval from memory. In this Chapter, two types of fluency, word fluency and ideational fluency will be examined.

There are a few studies indicating that verbal fluency is significantly poorer in ASD groups than typically developing control groups. Pastor-Cerezuela,

Fernández-Andrés, Feo-Álvarez and González-Sala (2016) found that in a sample of 5- to 8-year-old children with and without ASD, children with ASD scored lower in semantic word fluency task than those without ASD. Chronological age is the

predictor of semantic word fluency ability in children without ASD, verbal IQ is the best predictor in the ASD group, which indicates that better linguistic competence would contribute to verbal fluency ability.

Inokuchi and Kamio (2013) suggested that in their qualitative analyses, children with high-function autism had fewer correct responses on verbal fluency when compared to age-, gender- and IQ-matched control group. Also, Turner (1999) found that for both word fluency and ideation fluency tasks, an autistic group

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generated significantly fewer responses compared to a control group. In addition, word fluency was found to be correlated with verbal IQ and ideational fluency.