Summary and Aims of the Thesis

This chapter began by considering the overlap between behavioural inflexibility in ASD – now conceptualised as RRBs – and the more elusive concept of imagination that may be related to it. My overall goal was to examine the relationship between imagination and RRBs in autistic adults. However, before this issue can be properly considered, there are a number of obstacles to overcome; the first being arriving at a definition of imagination. I began this literature review by undertaking a conceptual analysis of imagination, resulting in the following definition: generation and flexible manipulation of existing concepts to form novel ideas, which may be rooted in past experience and may result in adaptive outputs (creativity). In reviewing the

imagination literature, I described a wide variety of measurements and evaluated their usefulness in relation to this definition, and also found that few studies took into account different dimensions of imagination. Most studies focus on fluency to the neglect of originality and flexibility, including studies that examine the relationship between imagination and RRBs, and so most previous research does not assess a complete picture of imagination in ASD. Related to this, few studies have measured

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imagination in autistic adults, and therefore very little is known about this construct in adulthood.

Reviewing the literature regarding the measurement and categorisation of RRBs in ASD, the lack of empirical information about RRBs in autistic adults became

apparent. RRBs have been measured in a variety of ways, and generally can be

categorised into RSMB and IS, but little effort has been made to assess RRBs in autistic adults. Many of the measures that have been developed are unsuitable for use with autistic adults, as they focus on child behaviours and rely on parent-report, which leads me to the next issue that should be addressed before assessing the relationship between imagination and RRBS. At the time of designing the studies for this thesis there was no published measure of self-reported RRBs suitable for autistic adults. The YBOCS, described earlier (page 40), can be used as a self-report measure but it has not been adapted for use with adults with ASD, unlike the child version (Scahill et al., 2006) and was originally designed for use with individuals with OCD, which as I have

described may not be useful for assessing the presentation of RRBs in ASD (page 40). The AQ (Baron-Cohen et al., 2001) includes items related to RRBs (e.g., It does not upset me if my daily routine is disturbed). However, the original sub-scales of the AQ do not include RRBs, and only two factor analyses have identified an RRB subscale (Kloosterman et al., 2011; Lau, Kelly, & Peterson, 2013) and therefore it is not suitable as a measure of RRBs. Finally, there is an adult version of the Childhood Routines Inventory (Evans et al., 1997); however, this had not yet been published at the time of designing the studies for this thesis8_{. Therefore I developed the RBQ-2A in order to}

provide a self-report measure of RRBs in autistic adults. As a major part of assessing the RBQ-2A’s reliability, I analysed its structure using PCA in Chapters Three and Four. As with imagination, different sub-categories of RRBs should be assessed when

examining the relationship between RRBs and imagination, due to previous evidence that this relationship is specific to IS (Turner, 1997). Therefore assessing the factor structure of the RBQ-2A is not only important for reasons of psychological validity (see Chapter Two, page 61), but also to distinguish items that relate to IS from items that relate to RSMBs, in order to assess whether or not the relationship between RRBs and

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imagination is specific to IS. The RBQ-2A’s other psychometric properties in terms of reliability and validity are assessed in Chapters Three to Five.

Having developed and assessed a satisfactory measure of RRBs for autistic adults, I sought to address the primary question of this thesis in Chapters Four and Five. That is: what is the nature of the relationship, if any, between imagination and RRBs in autistic adults? Previous research is inconsistent; however, there is

preliminary evidence that RRBs are related to imagination in ASD (e.g. Harrop et al., 2014; Honey et al., 2007) and this may be specific to IS (Turner, 1997; although see Harrop et al., 2014). Specifically I investigated the relationship between the different RRB subscales and imagination in accordance with the three key components of imagination that I identified at the beginning of this chapter (fluency, originality, and flexibility).

My definition of imagination informed my decision making in terms of what types of imagination to assess and what tasks to use (see Chapter Two, page 75 onwards for more detail). Given that autistic individuals may show very different profiles of imagination (i.e. low fluency and high originality [Liu et al., 2011]), it was important to assess all three components as part of this thesis. In Study Five, fluency is assessed across three tasks (design fluency, ideational fluency and thinking about the future), originality across two (design and ideational fluency), and flexibility in one (ideational fluency). Study Four’s imagination measures do not map onto these

components, as I used questions about past pretend play and the imagination subscale of the AQ. Both measures have their weaknesses (see Chapter two, pages 75-77), and the use of the AQ subscale was opportunistic (page 77); however, I decided it was important to include a measure of pretend play as this is one of the most commonly used methods for assessing imagination in ASD. It was not possible to measure the three key components of imagination from the pretend play questions, as I did not have enough detailed information from my participants. However, pretend play is a construct which could be measured according to these three components using observational methods and this is discussed in Chapter six (pages 183-184).

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No study to my knowledge has investigated the relationships between different scales of RRBs and different dimensions of imagination in a single sample with ASD; as I have mentioned, Best et al. (2015) did not separate out their participants with ASD, nor were they able to confirm diagnoses. As well as being able to assess the

relationship between imagination and RRB in a more detailed fashion, this strategy enabled me to assess a wide range of imaginative abilities in autistic adults for the first time. The relationship between imagination and RRBs in autistic adults is directly addressed in Chapters Four and Five of this thesis, along with the relationship between the three components of imagination in Study Five. The next chapter describes the main methodological issues that arose while carrying out the work for this thesis and how they have been addressed.

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