A Double-Edged Sword? Factors Associated with Increased Perceptual Capacity in Autistic and Non-Autistic Individuals.

Background: Recent studies show that, for autistic people, perceptual capacity (the amount of sensory information processed at any one time) is increased in the auditory (Remington et al., 2016) and visual domains (e.g. Remington et al., 2012). This increase in perceptual capacity may be responsible for both positive (superior auditory perception skills) and negative (increased distractibility) aspects of the condition. It remains unknown, however, what is driving this difference and whether it is specific to autism. Answering this question is vital in order to establish how to capitalize on the additional perceptual capacity and support the challenges associated with it.

Objectives: The current study examined whether altered perceptual capacity is associated with sensory sensitivities or anxiety levels, rather than general autistic traits. Both sensory experiences (e.g. Baron-Cohen et al., 2009; Dunn, 1997) and anxiety levels (Croen et al., 2015; Simonoff et al., 2008; van Steensel, Bogels & Perrin, 2011; van Steensel & Heeman, 2017; White et al., 2009) have been shown to be altered for those on the autistic spectrum compared to their neurotypical peers. Further, increased perceptual capacity has also been found in other groups with higher anxiety (e.g. Sadeh & Bredemeier, 2011). It is possible, therefore, that increased perceptual capacity is not a characteristic of autism specifically, but rather is associated with sensory sensitivities or anxiety.

Methods: 73 adults (24 autistic and 49 neurotypical) 18-54 years, matched in age and cognitive ability took part in an auditory test of perceptual capacity (developed by Fairnie et al., 2016). The task, a dual-task paradigm, involved performing an auditory search task in the presence of varying numbers of distractors, while also performing a secondary detection task. Participants also completed three self-report questionnaires: 1) The Sensory Perception Quotient (Tavassoli et al., 2014) to quantify overall sensory symptoms in daily life (e.g. “I would be able to hear the sound of a vacuum cleaner from any room in a two-storey building“) 2) The Spielberger State-Trait Anxiety Inventory- T (STAI-T, Spielberger, Gorsuch, Lushene, Vagg, & Jacobs, 1983) and 3) The Social Responsiveness Scale (a measure of autistic traits, Constantino, 2002).

Results: Data collection and analyses are ongoing, however preliminary results suggest that there is a strong correlation between sensory sensitivity and perceptual capacity (r_s= .44, p=.002) and between level of autistic traits and perceptual capacity (r_s= .35, p=.015), but no such association with anxiety levels. Pre-registered planned regression analyses will explore the relative contributions of each of these factors.

Conclusions: The findings indicate that an increased perceptual capacity is associated with higher levels of autistic traits and sensory responsiveness in everyday life. This offers a target for autism-specific interventions, education and therapy and could assist in the development of improved sensory environments which are adapted to autistic people’s increased perceptual capacity.