3 What’s wrong with the ToM hypothesis? Deviance or delay?If deviant, then maybe modular; if delay, then modularity is less plausibleProblem: Happe (1995) meta-analysis suggests delayUniquenessIndividuals with sensory impairment also suffer delayUniversalityNot all people with ASD have difficulty with ToM tasks (Bowler, 1992)Hacking: getting the right answer by a different route (Frith et al, 1994)
4 What’s wrong with the ToM hypothesis? Continued… Problems with operational definitionFB task might be ok, but not clear about the justification for ‘mind in eyes’ task.Should a categorical disorder be investigated with a task that yields categorical data? FB task does the job, but ‘mind in eyes’ task gives graded data.
5 What’s wrong with the ToM hypothesis? Continued… Besides, it turns out that individuals with ASD are not specifically impaired in interpreting mental states from the eyes (Back et al, 2007)
6 What’s wrong with the EF hypothesis? Uniqueness… noADHD, OCD, Tourette, Schizophrenia….Universality… maybeOzonoff et al (1991): 96%Pellicano et al (2006): 50%Domain Specificity… maybe but probably not (pre-frontal cortex)Definition is just a list; EF is a function and neither a structure nor a mechanism (Zelazo et al, 1997)
7 What’s wrong with the EF hypothesis? Continued… Uniqueness in relation to components of EF?Planning (e.g. Tower of Hanoi). Impaired, but maybe linked with IQ.Mental Flexibility. Impairments in 9/14 studies but IQ again plays mediating roleInhibition. No difference between people with ASD on stroop task, though differences between populations are usually found on the windows task.Generativity. Mixed findings
8 Weak central coherence UniquenessUniversalityDomain SpecificityNo, cognitive styleModularityNo
9 What’s wrong with the theory of WCC? Problems with definition – at what level of processing is WCC supposed to be manifest?Low level, e.g. visual illusions: failure to demonstrate the effect (Ropar & Mitchell)Focus on detail at the expense of focus on global: But global precedence is apparent in the Navon task
10 What’s wrong with the theory of WCC? Continued… WCC isn’t a unitary constructPellicano et al (2006) presented a variety of tests that supposedly measure WCC and found not one but two factors using a factor analysis technique.Both of these factors were related with measures of executive function
11 Autism as a multiple deficit According to this account, autism is not a singular deficit but a collection of features that happen to coincide.According to Bishop & Norbury (2002), these features appear in different ways and to different degrees, in determining developmental outcome:E.g. ASD, ADHD, Tourette, pragmatic language impairment, dyslexia
12 ConclusionIt is unlikely that autism can be explained in terms of a singular factorIt is very likely that autism has a polygenetic basis, where the developmental outcome depends on environmental factors to some extentThe mix of genetic and environmental factors will probably determine whether the individual has ASD, ADHD, PLI, etc.