Very interesting! But is it a failure or advance? There are also theories that we are advancing.
A good point. It seems cognitive and neurological differences can be framed
pejoratively or
positively, depending on one's unconscious need to project
defects or
merely difference onto groups of people in society. Below are some ongoing attempts to understand a Bayesian explanation of perception in ASC individuals (ASC = Autistic Spectrum Condition).
Pellicano and Burr's (2012) Bayesian explanation of autistic perception
Some tenets of the theory
* People with autism see the world more accurately – as it really is.
* Autistic children make less use of prior information.
* The formal, computational principles of a Bayesian framework offer a way of [METAPHOR FOR?] identifying the causal mechanisms of altered autistic perception.
Bayesian decision theory refers to a decision theory which is informed by Bayesian probability. Bayesian decision theory is a principled description of the processes that enable observers to derive the most probable interpretations of their environment. It is a statistical system that tries to quantify the trade-off between various decisions, making use of probabilities and costs. For example, if we knew someone's age, we would be more accurate in estimating the probability that they have cancer. An agent operating under such a decision theory uses the concepts of Bayesian statistics to estimate the expected value of its actions, and update its expectations based on new information. These agents can and are usually referred to as estimators.
It has long been known that perceptual processing is unusual in autism. Similarly, it has been observed that in autistic individuals, the cerebral is whole and intact, but the physical is usually not of good service (William Stillman).
Areas where ASC individuals show exceptional cognitive strengths:
* on the Embedded Figures Test, finding hidden figures (e.g., a triangle) within larger meaningful drawings (e.g., a pram).
* less susceptible to illusions; less susceptibility to visual illusions.
* the prevalence of absolute pitch e.g., ‘naming the pitch of the ‘‘pop’’ of a cork’.
* enhanced performance on visual search tasks.
* superior visual discrimination.
* ability to process fine details.
* better discrimination abilities compared to typical individuals.
* an ability to show highly focused attention.
* privileged access to parts and details; an excellent eye for detail.
* better at copying impossible figures.
* are more accurate when asked to reproduce a slanted circle (ellipse) in the absence of perspective cues.
Pellicano and Burr (2012) argue that ASC individuals have less previous knowledge to colour or skew the probability of knowing something i.e., they aren't very 'Bayesian'. These authors link this difference to embodied cognition differences: "It is not sensory processing itself that is different in autism, but the interpretation of sensory input to yield percepts."
Just as we see in the Farmer, Baron-Cohen and Skylark (2017) paper ('People With Autism Spectrum Conditions Make More Consistent Decisions'), that ASC individuals are less influenced by decoy options when selecting target options, so priors improve the efficiency of computations by reducing overall noise or error.
Pellicano and Burr (2012): "[...] autistic people tend to perceive the world more accurately as a consequence of hypo-priors or reduced bias by prior experience, a notion that fits well with extant empirical data." (p. 509)
"[...] the possibility that the non-social symptoms of autism might be attributable to fundamental differences in sensation and perception" (p. 504)
The hypo-priors mean that ASC individuals experience everything afresh, rather than mediated by prior knowledge and expectations. (p. 508)
A nuance: Pellicano and Burr (2012) are not saying that individuals with autism have no priors but rather that their priors are broader. This means that they have fewer internal constraints on perception – that is, hypo-priors. Their theory is that hypo-priors should sometimes result in more ‘accurate’ perception.
Bayesian priors sacrifice accuracy (understood as average closeness to physical reality) for improved precision (reliability), resulting in an overall reduction of error. So the perceptions of autistic people are more accurate but overall less reliable?
Evaluation of this theory
How easy it would be to interpret this difference from the norm as a defect or failure (e.g., "ASC individuals fail in the process of contextual meaning and prior knowledge" or "a failure to attenuate sensory precision and contextualise sensory information in an optimal fashion"... "Often they do not understand situations or contexts they have already seen before", "ASC individuals lack a priori beliefs about the world"). (Similarly, of the finding that 'People With Autism Spectrum Conditions Make More Consistent Decisions', some people refuse to accept that this might be a positive trait --- instead of calling ASC thinking "more rational", they prefer to call it "more rigid").
However Pellicano and Burr (2012) frame this difference more positively: "people with autism see the world more accurately – as it really is – as a consequence of being less biased by prior experiences." i.e., it seems that ASC individuals are not distracted as much as neurotypical individuals are by context and previous assumptions (does this include meanings and value-judgements?). But might this be associated with the non-social symptoms in autism – the weaknesses and the strengths? e.g., perhaps a detail-focused processing style causes the characteristic ‘insistence on sameness’, including adherence to routines and an aversion to unexpected and unpredictable events, as well as sensory atypicalities (such as extreme sensitivity to florescent lighting or to the sound of the school bell).
Linked to this: It has been shown that arousal causes perceptual narrowing, that is, it reduces the range of cues that an organism attends to and uses (Easterbrook, 1959).
