Características de la población desplazada

It is important to consider the characteristics of participants to be targeted for recruitment in each study of the thesis. For the first study assessing the RBQ-2A, the

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aim was to test whether the questionnaire is reliable in a typical population. University students were targeted as it is easy to recruit large numbers from this population and they form the starting point in the development of many

questionnaires. This population is of course inherently limited by the fact they tend to be young and, in the case of psychology students, female. For the second study a more representative sample that included participants with ASD was analysed in order to provide a brief test of the reliability and validity of the RBQ-2A in autistic compared to NT individuals. The third and fourth studies were conducted with participants reporting a clinical diagnosis of ASD. The data collection for these studies was conducted online in order to maximise the number of participants that could be recruited. Initially this sample was intended to include only participants from the United Kingdom (UK); however, issues with recruitment resulted in individuals from other countries taking part (see Chapter Four, page 107 for further explanation and discussion of this). As the original intention was to only recruit participants from the UK, and the survey’s demographic questions were aimed at British individuals, only the UK participants have been included in this thesis; however, this dataset does provide the opportunity to analyse the RBQ-2A in other national populations in the future.

The final study of this thesis involves conducting a range of imagination tasks with participants. For this study, another group of autistic individuals ranging in age and gender were recruited, and were asked to provide some evidence of their

diagnosis (the DISCO was also used to confirm diagnoses). When initially designing this study and selecting the imagination tasks to be used, I intended to recruit a control group. However, due to time constraints this was not possible and so I intended to use population norms available for the standardised creativity measures (described in the following section) in lieu of a control group. Unfortunately, it later transpired that the publishers of these creativity tests do not make the norms for individual subtests available to administrators, and therefore it was not possible to use norms as only subtests were used (see page 77 for a discussion). Lack of a control group is not necessarily an issue for the central question of this thesis; namely, the relationship between imagination and RRBs in autistic adults. The most important role for a control group in this thesis is in testing the reliability and validity of the RBQ-2A, and a control

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group was available in Study Two. In terms of understanding the profile of imagination in ASD, the lack of a control group does limit this somewhat, but only in the sense of how imagination may differ from the general population. However, it has been argued that studies employing a matched control group design are limited in terms of what they can tell us about the autistic population as a result of its heterogeneity (Jarrold & Brock, 2004).

In terms of inclusion and exclusion criteria, Study One specifically targeted university students across several waves of recruitment, and in one of these waves male students were targeted in order to address the gender imbalance of the sample. Other than this study, there were no inclusion or exclusion criteria in terms of gender. In Study Two both autistic and NT participants were recruited. Studies Three-Five targeted only autistic participants. The only exclusion criterion for age that was

implemented across studies was that participants should not be younger than eighteen years as I was specifically targeting adults; the exception is for Study Two. Study Two consists of a secondary analysis of data collected as part of a study on the role of cortisol and melatonin in sleep disturbance in ASD. As such participants’ ages were restricted to between 25 and 39 years due to the distinct developmental pattern of the melatonin rhythm cycle across the lifespan.

A more pertinent issue relating to selection of participants is ability. Ability in terms of IQ and independence varies greatly within the autistic population, ranging from people who are non-verbal and require a high level of support in their daily lives, to those who score extremely highly on IQ tests and need less support. Research tends to focus on participants who are verbal with higher cognitive ability, which is a

weakness of the ASD literature. Due to the nature of the questionnaire and tasks implemented in this thesis, participants were required to be fluent in both written and spoken English to take part; although this was the only specific criterion relating to IQ or ability, this would result in a sample that is heavily skewed towards cognitively able participants (although many of my participants did have other support needs, for example in terms of social skills). For the final study I also tested the IQs of participants to ensure that they met the cut-off of 70 for average intelligence

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analysis. As the characteristics of the target population limits the generalisation of any findings from the thesis to a cognitively able adult population of autistic adults, I will take this into account when interpreting the results from all of the studies. The following section discusses methodological issues in terms of assessing imagination in ASD, as well as how these imagination measures may be used in a satisfactory way with the RBQ-2A given that the latter is a questionnaire and not an experimental task.