Abstract
Individuals with autism spectrum disorder (ASD) are diagnosed with impairments in social and communicational abilities, poor social interaction skills, and repetitive and inflexible behavioral patterns that cause several difficulties. The severity of these deficits is significantly influenced by the general executive and linguistic impairments of the individual. A large area of cognitive functions is executive functions (EF), the dysfunction of which is present throughout development in ASD, as there is evidence for both their typical and atypical development. Further, even though language impairment is not included in the DSM-V diagnostic criteria, it has been related to ASD. The purpose of this chapter is to present recent findings regarding both executive and linguistic impairments of children with ASD.
Top1. Executive Impairments Of Children With Asd
EF are defined as cognitive processes that enable us to think before we act, resist temptations or impulsive reactions, stay focused, reason, problem-solve, flexibly adjust to changed demands or priorities, and see things from different perspectives (Diamond & Ling, 2016). EF are of high importance in the research of ASD for two main reasons; i., they may account for the heterogeneity in symptoms in ASD and ii., EF are predictive of preschoolers’ later school readiness and academic success in reading and mathematics (Pellicano, 2012). There is an agreement that EF include three skills, inhibition, working memory (WM) and cognitive flexibility (CF) (Diamond, 2013). Children and adolescents with ASD often exhibit various deficits in some processes of EF (Friedman & Sterling, 2019).
1.1 Inhibition
Inhibition allows us to control our attention, behaviour, thoughts, emotions in order to give appropriate responses and override a strong internal predisposition or external lure (Diamond, 2013). Ιn ASD, there are some common, repetitive and stereotyped behaviours that indicate the lack of inhibitory control (Faja & Darling, 2019). A group of research shows that there are no differences in inhibition between children with ASD and typically developing (TD) children. Goldberg et al. (2005) showed that inhibition is not impaired in high functioning (HF) children aged from 8 to 12 years with ASD. Ozonoff and Strayer (1997) showed also that HF children with ASD (with mean age 13.9 years) were unimpaired on inhibition. Russell et al. (1999) claimed that children with ASD are challenged by executive tasks. They showed that children could complete an executive task that requires a prepotent response but does not require the following of an arbitrary, novel rule.
On the other hand, there is another line of research that indicate some deficits in inhibition in ASD (e.g., Bishop & Norbury, 2005). Christ et al. (2007) showed that children with ASD from 6 to 12 years of age experienced circumscribed deficits in some aspects of inhibition, measured with three kinds of tasks (Stroop, flanker, and go/no-go tasks). In detail, their performance was impaired on the go/no-go task and on the flanker interference task. The result of the Stroop task is very similar to those of Ozonoff and Strayer (1997) who also did not find an impairment on inhibition. Geurts et al. (2004) found evidence for difficulties in children with HF ASD, aged from 6 to 13 years old, in inhibiting a prepotent response and inhibiting an ongoing response.
There are some explanations for these contradictory findings. One explanation is that the cohorts of children with ASD participated in the studies may vary in an important way (Christ et al., 2007). Another explanation is that the different tasks measuring inhibition (e.g., such as Stroop or go/no-go) may assess different aspects of inhibition (Tonizzi et al., 2022). Characteristics of the task could affect performance because of i. the format (i.e., if it is computerized or not), ii. the abilities that are required by the task (i.e., verbal or motor abilities) and iii. the indices that each study considered (i.e., accuracy or reaction times) (Tonizzi et al., 2022).
Key Terms in this Chapter
Cognitive Flexibility: The ability to move from one mental set to another.
Pragmatics: The use of social and non-social language we communicate with others.
Inhibition: The ability to inhibit a spontaneous response in order to rethink the answer.
Phonology: The organization and production of the system of sounds in a word and the intonation we use.
Morphology: Rules regarding the use of morphemes.
Working Memory: The ability to maintain and process information mentally.
Syntax: The grammatical rules of a language - that is, how words are connected in phrases and sentences.