Research question 2 considering the nature of the children’s sensory profiles and research question 4, exploring whether children with certain sensory profiles may benefit
111
more or less from the programme, necessitated the use of a standardised sensory profile questionnaire to establish their profiles.
As levels of agreement between parent and self-report in autism research has been mixed (Jepsen, Gray, & Taffe, 2012; Bitsika, Sharpley, & Mills, (2016), researchers have suggested a multi-informant approach as a useful strategy and indicative of best practice (Silverman & Ollendick, 2005). Such an approach was followed in this study by using both caregiver and self-report measures.
3.3.1.1 The Adolescent-Adult Sensory Profile.
Widely used assessments for sensory processing research is now the suite based on Dunn’s model, namely the Sensory Profile (Dunn, 1999), the Short Sensory Profile (Dunn, 1999) and the Adolescent, Adult Sensory Profile (Brown & Dunn, 2002), making
comparisons of studies less difficult (Burns, Dixon, Novack, & Granpeesheh, 2017). The AASP is a self-report questionnaire, standardised for individuals between the ages of 11 – 65 but not on an autistic population. It has good internal consistency and convergent validity with an autistic population (Pfeiffer, Kinnealey, Reed, & Herzberg, 2005) and has been validated using measures of skin conductance and habituation (Brown et al., 2001).
The AASP is a 60-item self-report scale consisting of four 15-item subscales, containing statements about different responses to various sensory stimuli. The subscales cover four sensory quadrants; Sensory Sensitivity (passive) and Sensory Avoidance (active) targeting low thresholds and Sensation Seeking (active) and Low Registration (passive) targeting high thresholds. Participants are asked to rate each item on a 5-point Likert scale ranging from 1 (‘almost never’) to 5 (almost always). The AASP is a norm- referenced instrument and, based on scores provided for each quadrant, an individual’s performance can be categorised via one of five categories. This scoring system is summarised in Table 24.
112
Table 24
Scoring Criteria for the AASP.
• ‘Much Less Than Other People’ which is at least two standard deviations below the normative mean and signified by ‘- - ‘(double minus).
• ‘Less Than Other People’ which is at least one standard deviation but less than two, below the normative mean, signified by ‘– ‘(single minus).
• ‘Similar to Other People’ which is typical performance signified by 0.
• ‘More than Other People’ which is at least one standard deviation but less than two, above the normative mean, signified by ‘+ ‘(single plus).
• Much More Than Other People’ which is at least two standard deviations above the normative mean, signified by ‘++ ‘(double plus).
3.3.1.2 The Sensory Profile Checklist Revised.
As the presence of additional sensory perceptual difficulties, which are separate from sensory modulation and thus not identified in a standardised questionnaire such as the AASP, may have confounding influences on the programme, it was considered prudent to include an additional measure, which had the added benefit of incorporating parental and staff perspectives.
Bogdashina’s (2003) seminal text on sensory-perceptual issues draws attention to an additional predominance of sensory discrimination and praxis difficulties in autism. Based on information provided from personal accounts of autistic individuals and close observations of autistic children, Bogdashina (2003) produced the Sensory Profile Checklist Revised (SPCR) as a screening for compiling a broader-based sensory profile. The SPCR is a 232-item parental/caregiver questionnaire, which includes 20 categories through all 7 sensory systems to cover possible patterns of autistic people’s sensory experiences. Bogdashina emphasised that not all these sensory experiences are
dysfunctional, as some of them could be classified as strengths rather than weaknesses, for which she termed as ‘superabilities’.
The questionnaire focuses on the 7 sensory modalities in blocks, namely visual sensory and perceptual processing (Items 1 -50), auditory sensory and perceptual processing (items 51-92), tactile sensory and perceptual processing (items 93-125), olfactory sensory and perceptual processing (items 126-150), gustatory sensory and perceptual processing (items 151-175), proprioceptive sensory and perceptual processing (items 176-207) and vestibular sensory and perceptual processing (items 207-232).
113
The SPCR is not standardised but has good internal consistency with alphas ranging from .90-.95 (Robinson, 2010). High correlations between items of the SPCR; the Autism Quotient (AQ; Baron-Cohen et al, 2001) and the AASP (Pearson’s correlation coefficient +.659) suggest that the SPCR is a more useful and in-depth tool than the AASP for evaluating the sensory and perceptual experiences of individuals with autism
(Robinson, 2010).
3.3.1.3 The sensory matrix.
Lombard (2015) indicated that whilst the AASP provided a solid and standardised overview of one’s sensory profile, more clarity was required with regards to each sensory system in order to provide enough information for intervention and strategy
implementation. She therefore expanded the sensory sections to include five questions on each of the four sensory systems (20 questions in total) under the respective headings of Smell/Taste Processing, Visual Processing, Touch Processing, Auditory Processing, Movement Processing and Activity Level. This expansion had the added benefit of identifying fluctuating profiles more easily. Unlike the AASP required responses are binary yes/no rather than a frequency-based Likert scale.
High threshold (sensation seeking and low registration) responses are each allocated a +1 score whilst low threshold responses (sensation seeking and sensory avoidance) are allocated a – 1 score. Total scores (by deducting minus from plus scores) under each modality are transferred to a summary score sheet. The total accumulative score is then translated into a Sensory System using the analogy of a tree. An adapted copy of the Sensory System is provided in Appendix 17.
A Sensory Tree was designed as a user-friendly analogy to understand profiling and behaviours and was deemed to work particularly well with exploring relationship dynamics (Lombard, 2015). The classification is summarised in Table 25.
114 Table 25
Sensory Tree to Understand Behaviours (Lombard, 2015).
Note: Permission to reproduce the table has been granted by the author.
3.3.1.4 The Sensory Processing Sensitivity (SPS) Scale (Child).
Serious consideration was also given regarding the use of the SPS Scale (Child) (Pluess et al., 2018). On the grounds that the ‘Sensory Intelligence’ approach is inclusive and avoids diagnostic labels, it was considered unwise and also possibly unethical to introduce another ‘label’, however, with the added complication of insufficient time to do justice to what is known about Sensory Processing Sensitivity which remains an emerging construct.
3.3.1.5 Summary of sensory profiles used.
The sensory profiles of each child were, therefore, obtained by the completion of three questionnaires. Each child completed the Adolescent-Adult Sensory Profile (Brown
115
and Dunn, 2002), to acquire standardised information and the Sensory Matrix, as an
expanded version of the AASP. The Sensory Profile Checklist Revised (Bogdashina, 2003) was also completed by the parents with help from school staff, for triangulation purposes and to establish the possibility of additional perceptual difficulties, which would not be addressed by the programme.