Making Sense of the Perceptual Capacities in Individuals with and without Autism

Background:

Recent studies report 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 capacity may be responsible for both positive (superior auditory perception skills) and negative (increased distractibility) aspects of the condition. The question remains, however, whether this increase in capacity is associated with the real-life sensory experiences of autistic individuals. Those on the autistic spectrum often have altered sensory experiences compared to their neurotypical peers. In particular, sensory hypersensitivity is often reported to be distressing and uncomfortable by autistic individuals. Several theories (e.g. Baron-Cohen et al., 2009; Dunn, 1997) have proposed that sensory symptoms, in particular hypersensitivity - the heightened acuity of sensory experiences – may be linked to altered attention patterns. We hypothesise that increased perceptual capacity may be one such process underlying the atypical sensory sensitivities seen in the condition.

Objectives:

The current study aimed to explore the relationship between perceptual capacity and sensory hypersensitivity. Understanding this association may help inform the creation of therapeutic interventions to minimise sensory distress.

Methods:

Eighteen autistic and 19 neurotypical participants between 18-35 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 a self-report sensory questionnaire (the Sensory Perceptual Quotient by 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.“).

Results:

In line with initial predictions, a positive correlation (r_s= .42, p=.01) between level of perceptual capacity and sensory sensitivities was found. This shows that extra perceptual ability is related to the sensory perception of real-life events.

Conclusions:

The findings indicate that an increased perceptual capacity is associated with increased levels of sensory responsiveness in every-day life. Crucially, this allows a reframing of increased sensory sensitivity in terms of the increased perceptual capacity, rather than a filtering deficit or an insufficient focus. This offers a target for interventions, education and therapy and could assist in the development of improved sensory environments which are adapted to a persons’ perceptual capacity.