Making sense of the perceptual capacities in autistic and non-autistic adults

Abstract

Perceptual capacity refers to the amount of information that we can pay attention to at any one time. Research has shown that autistic people have a higher perceptual capacity, which means they can take in more information than non-autistic people can. This can be useful in certain situations, for instance, hearing approaching cars or noticing small details. However, in other situations, a higher perceptual capacity may result in more distraction. This study looked at whether having this increased perceptual capacity is linked to being very sensitive to sensory information (lights, sounds, touch, taste and smell) - something that many autistic people experience on a daily basis. Being very sensitive to these things can make it hard to interact with the world around us, so it is important to know more about what causes the sensitivity. To explore this, 38 autistic and 66 non-autistic adults completed a computer task that measured perceptual capacity and filled in a questionnaire about how sensitive they were to sensory information. We found that perceptual capacity was related to sensory symptoms for both autistic and non-autistic participants; people who had a larger perceptual capacity showed more sensitivity, while people who had a lower perceptual capacity showed reduced sensory sensitivity. This information can hopefully be used to improve the way in which we can support people who experience unpleasant sensory sensitivity.

Keywords: adults; attention; autism; perception; perceptual capacity; sensory processing.

Figure 1.

Auditory load task developed by (Fairnie et al., 2016). Possible locations of the animal sounds were placed in the numbered circles 1–6 in the inner ring, whereas circle A–E on the outer ring represents possible locations of the critical stimulus. The sound of the critical stimulus was 9 dB quieter than the sounds of the target stimulus. The milliseconds next to the circles are the interaural time differences, the time the sound needs to travel to the contralateral ear. The ratios (in grey) represent the interaural amplitude difference – the relative amplitude difference between the ears.

Figure 2.

The detection sensitivity (A) for each group at each set size. Note. The figure represents a section of the scale ranging from .75 to 1.0, the error bars represent the standard error of the mean.

Figure 3.

Scatterplot of SPQ score and the descent in detection sensitivity between set size 1 and 6 (A-drop). Note: Negative, constant or small positive values of A-drop from set size 1 to 6 reflect higher perceptual capacity. For the SPQ, the lower scores indicate higher sensory.