Sensory-inclusive spaces for autistic people: We need to build the evidence base

Given the considerable impacts that sensory processing can have on autistic people’s mental health and quality of life (MacLennan et al., 2020; Pfeiffer et al., 2005), it is encouraging to see an ever-growing literature on autistic sensory processing. However, to date, most research has focused on the sensory processing characteristics of autistic individuals themselves (e.g. Proff et al., 2022, for review), with far less consideration of the aversive sensory environments that place such high demands on autistic people’s sensory processing. Yet, autistic people have told us that sensory environments can be extremely overwhelming and can present barriers for accessing certain places like supermarkets, eateries, large shops, schools and medical settings (Doherty et al., 2022; Howe & Stagg, 2016; MacLennan et al., 2022; Parmar et al., 2021; Williams et al., 2023). Accordingly, within the United Kingdom (where we are based), the National Strategy for Autistic Children, Young People and Adults (2021–2026) aims for ‘many more businesses, public sector services and different parts of the transport system to become more autism-inclusive, so that autistic people can access these spaces and services, just like everyone else’ (UK Government, 2021). And internationally, the United Nations (2022) have called for the provision of inclusive and accessible public spaces for all by 2030, requiring the balancing of different access needs. These policies recognise the need to adapt sensory environments to improve inclusion and physical and mental health of autistic people. There are a growing number of recommendations, many co-produced with autistic people, to help organisations and services become more accessible for autistic people. For instance, the UK’s National Development Team for Inclusion (NDTI, 2020) disseminated a report on how to meet the sensory needs of young autistic people in mental health in-patient services, and the ASPECTSS Design Index proposes seven design principles to improve the built environment for autistic people (Mostafa, 2015). Most recently, the British Standards Institution (BSI, 2022) published the Design Standard on Neurodiversity and the Built Environment (PAS 6463), which provides guidance on creating sensory-inclusive environments for a range of neurodivergent groups, to meet both social and legal obligations. In addition to design standards, initiatives have been put in place to modify how spaces are used across the world with the intention of making places more sensoryinclusive for autistic people and others with sensory processing differences. For example, the Sunflower Lanyard scheme has been introduced to allow those with hidden disabilities to communicate that they may need additional support or time in public places, such as airports, by wearing a lanyard (Hidden Disabilities Sunflower Scheme, n.d.). Many large supermarket chains and retail centres have introduced ‘quiet hours’, in which sensory input is reduced, for example, by turning off background music and reducing the volume on checkout machines (de la Fuente & Walsh, 2022). There has also been an increasing provision of designated quiet spaces in sporting and entertainment venues (e.g. ‘sensory-friendly’ spaces in City of Surrey (n.d.), Canada; football stadiums in the FIFA World Cup [El Akoum & Dyer, 2022]). Within theatre, ‘relaxed performances’ have been introduced, which reduce sensory input and provide a non-judgmental environment for autistic audience members (Fletcher-Watson & May, 2018). While these initiatives are relatively recent, autistic people have long considered these factors when creating autistic spaces, like the Autscape conference initiated in 2005 (Autscape, 2023). Steps have also been made to make whole towns more inclusive for autistic people. Clonakilty became Ireland’s first ‘Autism-Friendly’ town after a range of public services, schools and businesses made changes to become more autism-inclusive (Clonakilty, n.d.). Blackpool Council in the United Kingdom has begun developing their ‘Blackpool Ambition for Autistic People’ strategy, with the view to adopting a whole-town, cross-sector approach to enabling autistic thriving (Blackpool Council, 2022). In Canada, a community-driven initiative led to Channel-Port aux Basques, Newfoundland, receiving official ‘autism-friendly’ status (Howes, 2023). However, the empirical evidence base to substantiate these guidelines and initiatives is sparse. Research has identified that there are multiple factors that need to be considered when making spaces more enabling for autistic people, and these go far beyond just reducing sensory input (Doherty et al., 2023; Garner et al., 2022; MacLennan et al., 2022; Stogiannos et al., 2022). MacLennan et al. (2022) identified six principles determining how disabling or enabling sensory environments are, which include Sensory-inclusive spaces for autistic people: We need to build the evidence base 1183541 AUT0010.1177/13623613231183541AutismEditorial editorial2023

Given the considerable impacts that sensory processing can have on autistic people's mental health and quality of life (MacLennan et al., 2020;Pfeiffer et al., 2005), it is encouraging to see an ever-growing literature on autistic sensory processing. However, to date, most research has focused on the sensory processing characteristics of autistic individuals themselves (e.g. Proff et al., 2022, for review), with far less consideration of the aversive sensory environments that place such high demands on autistic people's sensory processing. Yet, autistic people have told us that sensory environments can be extremely overwhelming and can present barriers for accessing certain places like supermarkets, eateries, large shops, schools and medical settings (Doherty et al., 2022;Howe & Stagg, 2016;MacLennan et al., 2022;Parmar et al., 2021;Williams et al., 2023). Accordingly, within the United Kingdom (where we are based), the National Strategy for Autistic Children, Young People and Adults (2021-2026) aims for 'many more businesses, public sector services and different parts of the transport system to become more autism-inclusive, so that autistic people can access these spaces and services, just like everyone else' (UK Government, 2021). And internationally, the United Nations (2022) have called for the provision of inclusive and accessible public spaces for all by 2030, requiring the balancing of different access needs. These policies recognise the need to adapt sensory environments to improve inclusion and physical and mental health of autistic people.
There are a growing number of recommendations, many co-produced with autistic people, to help organisations and services become more accessible for autistic people. For instance, the UK's National Development Team for Inclusion (NDTI, 2020) disseminated a report on how to meet the sensory needs of young autistic people in mental health in-patient services, and the ASPECTSS Design Index proposes seven design principles to improve the built environment for autistic people (Mostafa, 2015). Most recently, the British Standards Institution (BSI, 2022) published the Design Standard on Neurodiversity and the Built Environment (PAS 6463), which provides guidance on creating sensory-inclusive environments for a range of neurodivergent groups, to meet both social and legal obligations.
In addition to design standards, initiatives have been put in place to modify how spaces are used across the world with the intention of making places more sensoryinclusive for autistic people and others with sensory processing differences. For example, the Sunflower Lanyard scheme has been introduced to allow those with hidden disabilities to communicate that they may need additional support or time in public places, such as airports, by wearing a lanyard (Hidden Disabilities Sunflower Scheme, n.d.). Many large supermarket chains and retail centres have introduced 'quiet hours', in which sensory input is reduced, for example, by turning off background music and reducing the volume on checkout machines (de la Fuente & Walsh, 2022). There has also been an increasing provision of designated quiet spaces in sporting and entertainment venues (e.g. 'sensory-friendly' spaces in City of Surrey (n.d.), Canada; football stadiums in the FIFA World Cup [El Akoum & Dyer, 2022]). Within theatre, 'relaxed performances' have been introduced, which reduce sensory input and provide a non-judgmental environment for autistic audience members (Fletcher-Watson & May, 2018). While these initiatives are relatively recent, autistic people have long considered these factors when creating autistic spaces, like the Autscape conference initiated in 2005 (Autscape, 2023).
Steps have also been made to make whole towns more inclusive for autistic people. Clonakilty became Ireland's first 'Autism-Friendly' town after a range of public services, schools and businesses made changes to become more autism-inclusive (Clonakilty, n.d.). Blackpool Council in the United Kingdom has begun developing their 'Blackpool Ambition for Autistic People' strategy, with the view to adopting a whole-town, cross-sector approach to enabling autistic thriving (Blackpool Council, 2022). In Canada, a community-driven initiative led to Channel-Port aux Basques, Newfoundland, receiving official 'autism-friendly' status (Howes, 2023).
However, the empirical evidence base to substantiate these guidelines and initiatives is sparse. Research has identified that there are multiple factors that need to be considered when making spaces more enabling for autistic people, and these go far beyond just reducing sensory input (Doherty et al., 2023;Garner et al., 2022;MacLennan et al., 2022;Stogiannos et al., 2022). MacLennan et al. (2022) identified six principles determining how disabling or enabling sensory environments are, which include (1) the 'Sensoryscape' (i.e. the intensity and nature of sensory input), (2) Space constraints, (3) Predictability, (4) Understanding from others, (5) Adjustments, and (6) Opportunity for Recovery (see Figure 1). Many of these principles are captured in existing initiatives and recommendations. For example, relating to the 'Predictability' theme, the BSI (2022) recommended providing sensory maps to make spaces more predictable, referring to an example from the Museum of London, UK. Meanwhile, in relation to the 'Understanding' theme, the NDTI (2020) recognised the need to increase the understanding of staff in in-patient settings, and Clonakilty's 'autism-friendly' town status required staff training across services, schools and businesses. However, the research by MacLennan et al. (2022) exposed that some adjustments are not fit-forpurpose. For example, some autistic people said that quiet hours at supermarkets are unsuitable as they are infrequent and at inconvenient times, and that the Sunflower Lanyard scheme was often misunderstood and not effective in getting autistic people the support they need. Importantly, initiatives and design guidelines cannot be considered to really represent inclusion until autistic people have confirmed that they feel included.
We need a much stronger evidence base to drive policy change and ensure that initiatives and guidelines are effective and beneficial for autistic people. We need to rigorously evaluate the impact of implemented or recommended adaptations on autistic people's willingness to come to public spaces, how included they feel in these spaces, and their quality of life. For example, it is important to test the impact of recommended adaptations to mental health inpatient settings on wellbeing and recovery rates of autistic people (Williams et al., 2023). It is also important to identify the specific parameters underlying optimal sensory environments for autistic people. For example, while visual patterns have been identified as being uncomfortable for many autistic people (MacLennan et al., 2021;Parmar et al., 2021), there is a lack of systematic research into the precise visual parameters (e.g. contrast levels) that are particularly difficult, and how this might vary among autistic people. Anecdotally, autistic people often report discomfort from LED lighting, yet the precise variables that contribute to this discomfort, such as flicker rate, have not been empirically determined (Buro Happold and NDTI, 2021). This is an issue of pressing importance as LED lighting is being increasingly adopted as an eco-friendly option. Developing an evidence base in this way will help design more specific adaptations and highlight which adaptations should be prioritised, in turn ensuring organisations implement effective and suitable adaptations.
In developing this crucial evidence base, we must also consider the representativeness and generalisability of our research. Studies on sensory environments and autism have so far mostly focused on school-aged children and young to middle-aged adults (e.g. Black et al., 2022;MacLennan et al., 2022;NDTI, 2020;Strömberg et al., 2022). Unless we include a wide range of people, including older autistic people (Michael, 2016) and those with intellectual disabilities, we cannot be sure designs and adaptations will work for everyone. As sensory needs vary across autistic people, and even within an individual over time (MacLennan et al., 2021), research must consider how adaptations can be tailored, as opposed to being 'onesize-fits-all' (MacLennan et al., 2022). Where adaptations cannot be flexible to suit individual needs, it is particularly important to ensure that what makes the environment accessible for some autistic people does not make it inaccessible for other autistic people, and moreover, that adaptations do not adversely affect other groups. It is commonly assumed that adaptations made for autistic people will also benefit non-autistic people (Williams et al., 2023), but this assumption needs to be empirically tested. For example, the effects of generally reducing sounds at self-checkouts or dimming the lighting in supermarkets would need to be tested carefully to ensure these adaptations are not detrimental to others, such as those who have hearing or visual impairments. Yet it is easy to see how other modifications, like providing advance information about sensory environments (e.g. photos on a website), could also help others, such as wheelchair users or people with anxiety or dementia, navigate the space.
Whereas many existing initiatives involve relatively small adaptations to existing structures (e.g. supermarket quiet hours), the Universal Design model ensures that environments are built with disabled people in mind from the outset. Applying Universal Design principles could ensure that design benefits people with diverse preferences and abilities rather than restricting the focus to autistic people (Milton et al., 2017). More design-based research, ideally produced or co-produced by autistic people, is needed to allow a Universal Design approach with autistic people in mind.
We also need to broaden the settings studied, as research into autism and the built environment has primarily focused on schools and homes (Black et al., 2022). More research is particularly needed into places that autistic people enjoy going, which can include outdoor spaces, but also stadiums, concert venues and clubs (MacLennan et al., 2022), and to consider the ways that these places can be optimised for autistic people's sensory needs. Another setting to be considered in future research is the criminal justice system. Although autistic people are more likely to be victims of crime than offenders, autistic people are nevertheless over-represented internationally in all areas of the criminal justice system, including prisons (Baldry, 2014;Criminal Justice Joint Inspectorate, 2021). In the United Kingdom, a recent Criminal Justice Joint Inspection Review of Evidence (Criminal Justice Joint Inspectorate, 2021) made a number of recommendations to improve services for neurodivergent individuals, including a call to create and enable 'neurodiversity-friendly' environments. The HM Prison and Probation Service and Ministry of Justice's (2023) response to this report acknowledged that they were limited by existing physical environments but that future prison build programmes would be informed by evidence on design principles. It is therefore important to build this evidence base.
It is also important to consider how we can ensure that the proposed research advances are translated into impact. One potential challenge is that research on sensory environments in autism is inherently interdisciplinary, spanning fields such as architecture, geography, psychology and disability studies, and existing policies and initiatives in different geographical contexts are disparate and disconnected. Therefore, a concerted effort is needed to connect knowledge and policy across disciplines and contexts. It is also important to work with businesses and service providers to identify barriers to the implementation of adaptations to the sensory environment, and ways that these can be overcome, for example, by identifying lowcost adaptations (Garner et al., 2022). Ultimately, however, for meaningful change we need to look beyond individual businesses and work towards policy-level and societal changes. It is not just adverse sensory environments that create barriers to autistic inclusion, but also the stigmatisation of autistic people who are overwhelmed by sensory environments (MacLennan et al., 2022). By building an evidence base, we can identify the best ways to make spaces more sensory-inclusive and enabling for autistic people.