When the world becomes ‘too real’: a Bayesian explanation of autistic perception

Abstract

Perceptual experience is influenced both by incoming sensory information and prior knowledge about the world, a concept recently formalised within Bayesian decision theory. We propose that Bayesian models can be applied to autism - a neurodevelopmental condition with atypicalities in sensation and perception - to pinpoint fundamental differences in perceptual mechanisms. We suggest specifically that attenuated Bayesian priors - 'hypo-priors' - may be responsible for the unique perceptual experience of autistic people, leading to a tendency to perceive the world more accurately rather than modulated by prior experience. In this account, we consider how hypo-priors might explain key features of autism - the broad range of sensory and other non-social atypicalities--in addition to the phenomenological differences in autistic perception.

Autonomic and brain responses associated with empathy deficits in autism spectrum disorder

“…Importantly, the current findings provide direct support for recent proposals suggesting that failures in Bayesian inference, and particularly aberrant precision (i.e., inverse variance) of the information encoded at various levels of sensorimotor hierarchies, may contribute to socio-emotional deficits in ASD (Friston, et al, 2013b; Lawson, et al, 2014; Pellicano and Burr, 2012). Specifically, abnormally high interoceptive precision (i.e., over reliance on ascending interoceptive information), in the context of interoceptive inference, would result in hypersensitivity of principal AIC neurons that provide downstream predictions of interoceptive signals (Friston, 2010; Seth, et al, 2011).…”

“…Physiologically, this precision or attention is thought to be mediated by the postsynaptic gain or sensitivity of neuronal populations reporting prediction error (Bastos, et al, 2012). The specific failure in ASD has been attributed to a relative increase in the precision of sensory evidence and over the precision of higher (extrasensory) beliefs (Friston, et al, 2013b; Lawson, et al, 2014; Pellicano and Burr, 2012; Quattrocki and Friston, 2014; Van de Cruys, et al, 2014). …”

Susceptibility to Optical Illusions Varies as a Function of the Autism-Spectrum Quotient but not in Ways Predicted by Local–Global Biases

“…According to prevailing theories, people with ASD favour local over global elements and see the world more objectively (e.g., Happé & Frith, 2006;Mottron et al, 2006;Pellicano & Burr, 2012). It then follows that susceptibility to optical illusions might diminish as autistic traits increase across multiple illusions that require an analysis of global structure, particularly those with strong between-object relational properties.…”

“…It then follows that experiences, or priors, are important in shaping visual perception. Pellicano & Burr (2012) proposed that the use of priors in persons with ASD is attenuated relative to typically developing people and therefore the active process of 4 formulating and testing hypotheses about the world is more immune to suggestion, which results in a tendency to perceive the world more objectively, and a desire to be in more familiar settings. Similar accounts have been developed over the last few years by other researchers (e.g., Davis & Plaisted-Grant, 2015;Lawson, Rees, & Friston, 2014;van Boxtel & Lu, 2013;Van de Cruys et al, 2014).…”

Local Versus Global Processing in Autism: Special Section Editorial

“…Recent attempts to frame this debate in the larger "bottom-up" versus "top-down" processing story may bear fruit in the near future, especially as this also feeds into the theoretical battleground around "predictive coding" theories of ASD (e.g. Pellicano and Burr 2012;Van der Cruys et al 2014;Lawson et al 2014). Once again the Leuven group are leading the way here with a valiant attempt at integration in the recent papers of VanMarcke and co-workers, who has demonstrated how both WCC and EPF may be seen as "hierarchy perturbations" within the context of the Reverse Hierarchy Theory of Ahissar and Hochstein (2004) (e.g.…”