Executive dysfunction in autism☆

Abstract

Abstract'Executive function' is an umbrella term for functions such as planning, working memory, impulse control, inhibition and mental flexibility, as well as for the initiation and monitoring of action. The primacy of executive dysfunction in autism is a topic of much debate, as are recent attempts to examine subtypes of executive function within autism and other neurodevelopmental disorders that are considered to implicate frontal lobe function. This article will review cognitive behavioural studies of planning, mental flexibility and inhibition in autism. It is concluded that more detailed research is needed to fractionate the executive system in autism by assessing a wide range of executive functions as well as their neuroanatomical correlates in the same individuals across the lifespan.2 Executive dysfunction in autism.Goldsmiths Research Online.'Executive function' is traditionally used as an umbrella term for functions such as planning, working memory, impulse control, inhibition and shifting set as well as the initiation and monitoring of action [1]. These functions share the need to disengage from the immediate environment to guide actions. Executive functions are typically impaired in patients with acquired damage to the frontal lobes as well as in a range of neurodevelopmental disorders that are likely to involve congenital deficits in the frontal lobes. Such clinical disorders include attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorder, Tourette syndrome, phenylketonuria, schizophrenia and autism spectrum disorder. It should be noted that executive dysfunction can be observed in those with acquired damage to non-frontal brain areas.Autism spectrum disorder is a developmental disorder characterised by impaired social interaction and communication as well as repetitive behaviours and restricted interests. It is a lifelong disorder and affects at least 0.6% of the population with males being affected three times more often than females [2,3]. Estimates of learning disability vary. In a recent review of epidemiological studies the percentage of individuals with a learning disability is given as 70% [4]. Although different labels are used to define people at each end of the spectrum (e.g. autism, Asperger syndrome), 'autism' will be used in this review to refer to the whole spectrum.In recent years three key cognitive theories and their variants have been investigated in an attempt to understand the link between the brain and behaviour in autism. The most well-known of these is the theory of mind deficit hypothesis [5][6][7][8][9][10], and another account is that of weak central coherence [11][12][13][14][15] (see Box 1). Although these two accounts together can explain many of the deficits and assets associated with autism, repetitive behaviours and restricted interests might best be explained by a third cognitive theory: that of executive dysfunction. Executive dysfunction in autismOver the past twenty years several executive functions have been studied in autism. In this rev...

Reduced functional connectivity between V1 and inferior frontal cortex associated with visuomotor performance in autism

“…Postmortem studies on cellular integrity suggest an increase in frontal cortical neuronal density, which may reflect abnormalities in neuronal proliferation, migration and apoptosis in autism (Bailey et al, 1998). Executive impairments observed in several studies further support frontal dysfunction (Hill, 2004;Minshew et al, 1997).…”

Social and attention factors during infancy and the later emergence of autism characteristics

“…First, both tasks have been previously validated with groups of typical infants (Farroni, Csibra, Simion, & Johnson, 2002;Holmboe, Fearon, Csibra, Tucker, & Johnson, 2008). Second, atypicality in both areas has been previously associated with autism in those who are diagnosed (Grice et al, 2005;Hill, 2004) and in unaffected siblings (Belmonte, Gomot, & Simon Baron-Cohen, 2010;Dalton, Nacewicz, Alexander, & Davidson, 2007) in childhood and/or adulthood.…”

“…Difficulties in executive function tend not to be as universal as those found in social communication (Hill, 2004). Moreover, similar deficits tend to be present in various developmental conditions including Attention Deficit/Hyperactivity Disorder and Tourette Syndrome, although some argue that a specific profile of executive dysfunction can be found in individuals with autism (Ozonoff & Jensen, 1999).…”

“…However, the performance of individuals with autism on tasks of planning and mental flexibility is consistently impaired (Hill, 2004).…”

La pragmatique dans les troubles du spectre autistique

“…En outre, la communauté scientifique doit encore élucider les raisons de difficultés dans les très nombreux aspects de l'interaction qui impliquent, à un degré plus ou moins fort, d'adopter la perspective d'autrui. Il pourrait, par exemple, s'agir d'un déficit exécutif plus général, situé particuliè-rement au niveau de la flexibilité cognitive [36,38]. D'autres auteurs invoquent un manque intrinsèque de motivation sociale [39], même si certaines études révèlent une conscience du partenaire conversationnel et une véritable volonté de transmettre un fil narratif [35,40,41].…”