Perceptual Averaging in Individuals with Autism Spectrum Disorder

Abstract

There is mounting evidence that observers rely on statistical summaries of visual information to maintain stable and coherent perception. Sensitivity to the mean (or other prototypical value) of a visual feature (e.g., mean size) appears to be a pervasive process in human visual perception. Previous studies in individuals diagnosed with Autism Spectrum Disorder (ASD) have uncovered characteristic patterns of visual processing that suggest they may rely more on enhanced local representations of individual objects instead of computing such perceptual averages. To further explore the fundamental nature of abstract statistical representation in visual perception, we investigated perceptual averaging of mean size in a group of 12 high-functioning individuals diagnosed with ASD using simplified versions of two identification and adaptation tasks that elicited characteristic perceptual averaging effects in a control group of neurotypical participants. In Experiment 1, participants performed with above chance accuracy in recalling the mean size of a set of circles (mean task) despite poor accuracy in recalling individual circle sizes (member task). In Experiment 2, their judgments of single circle size were biased by mean size adaptation. Overall, these results suggest that individuals with ASD perceptually average information about sets of objects in the surrounding environment. Our results underscore the fundamental nature of perceptual averaging in vision, and further our understanding of how autistic individuals make sense of the external environment.

Priors Bias Perceptual Decisions in Autism, But Are Less Flexibly Adjusted to the Context

“…The presence of a time‐order effect in the ASD group demonstrates that adults with ASD can implicitly infer the mean of the stimuli, and have their perception biased by this prior knowledge. This result is consistent with other studies involving children or adults with ASD and showing that their perception is indeed influenced by prior knowledge [Corbett et al, 2016; Croydon et al, 2017; Manning, Tibber, Charman, Dakin, & Pellicano, 2015; Sapey‐Triomphe, 2017; Van de Cruys et al, 2017]. As priors were found to modulate the perceptual experience of adults with ASD, it does not support the theory suggesting that ASD is characterized by uniformly weak priors [Pellicano & Burr, 2012].…”

“…These Bayesian theories of ASD were formulated based on post‐hoc interpretations of studies, but more recently, some empirical studies were designed to directly assess prior influence on perception in ASD. Behavioral studies showed that individuals with ASD were able to make perceptual averaging and were influenced by prior knowledge, suggesting intact priors in ASD [Corbett, Venuti, & Melcher, 2016; Croydon, Karaminis, Neil, Burr, & Pellicano, 2017; Ego et al, 2016; Van de Cruys, Vanmarcke, Van de Put, & Wagemans, 2017]. In contrast, some studies concluded on a decreased use of prior knowledge in children and young adults with ASD [Karaminis et al, 2016; Król & Król, 2019].…”

Relating the perception of visual ensemble statistics to individual levels of autistic traits

“…It should also be noted that our results here pertain directly to ensemble processing of the size of objects in an array, and these results may not generalize to ensemble processing of all types of stimulus features. Though these results are similar to previous findings of decreased ensemble processing of size, color, and facial identity (Corbett et al 2016;Maul et al, 2016;Rhodes et al, 2014;Van der Hallen et al, 2017), this decrease was not observed with ensemble processing of emotional expression (Karaminis et al, 2017) or with more homogeneous arrays (Van der Hallen et al, 2017). As such, future research incorporating multiple measures of ensemble processing across an array of stimulus features would be quite beneficial.…”

“…Individuals with ASD are able to represent some level of ensemble information, but this representation may be compromised when compared to TD individuals (Corbett, Venuti, & Melcher, 2016;Maul, Stanworth, Pellicano, & Franklin, 2016;Rhodes, Neumann, Ewing, & Palermo, 2014), though experimental variables such as ensemble heterogeneity may influence this effect (Van der Hallen et al, 2017). The results of the present study expand these latter findings to suggest that these findings are not constrained to individuals with a clinical diagnosis, but can also be observed in the general population relative to their individual level of autistic traits.…”

“…For instance, global perceptual averaging of ensemble information, such as color, may be compromised in individuals with ASD (Maul et al 2016), and ASD individuals show a reduced ability to average a set of faces (Rhodes et al, 2014). Likewise, individuals with ASD relative to their typically developed peers exhibit a reduced ability to estimate the mean size of a set of 16 circles via a two-alternative forced-choice task (it should be noted that this comparison was not directly reported, but calculations based on reported data show an effect size of d = 0.61; Corbett, Venuti, & Melcher, 2016). A second study exploring mean size estimation in ASD showed mixed results.…”