Predicting the Unpredictable: How Autistic Brains Experience the World, and Why it Matters for Neurodivergent Parents
One of our favourite nerdy things to talk about at The Neurodiversity Practice are theories that underlie neurodivergent processing.
Although no one theory is yet able to give a comprehensive account of autism (or ADHD), there are two theories in particular that we find helpful in understanding the autistic experience: Bottom-Up Processing, and Predictive Processing Theory. Let’s find out more about why these are so useful.
Bottom-up and top-down processing
Firstly, let’s think about “bottom-up” and “top-down” processing theory.
This theory describes two complementary ways the brain makes sense of the world. Bottom-up processing begins with raw sensory information: sights, sounds, smells, textures, and other bodily signals are taken in and then assembled into a meaningful perception. This approach is driven by what is actually present in the environment, and emphasises detail, accuracy, and sensory evidence.
Top-down processing works in the opposite direction, using prior knowledge, expectations, memories, and context to interpret incoming information quickly and efficiently. Instead of building perception from scratch, the top-down process runs a simulation of what a person is likely to perceive.
This approach is driven by what is actually present in the environment, and emphasises detail, accuracy, and sensory evidence.
Predictive processing theory
Next up: Predictive processing theory adds an extra layer to the bottom-up processing idea. It suggests that the brain is fundamentally a prediction-making system.
According to this theory, the brain constantly generates top-down predictions about what it expects to perceive and then compares those predictions with bottom-up sensory input. When the incoming information matches expectations, perception feels smooth and effortless. When it doesn’t, a “prediction error” occurs and the brain must either update its predictions, or pay closer attention to the sensory data.
Predictive processing therefore explains perception as a dynamic balance between sensory evidence and prior beliefs, with learning and adaptation happening through the continuous adjustment of that balance. The relative contribution of bottom-up, sensory information, and top-down predictions, as well as sensitivity to “prediction errors” is weighted differently in different brains and nervous systems.
In fact, research* suggests that many autistic nervous systems tend to lean more heavily on bottom-up information and rely less on top-down predictions, expectations and filters.
This can help us understand some of the key differences we see in autistic people’s experience of the world. If we follow these theories, it becomes very understandable that autistic people often feel sensory input more intensely, and become more easily overwhelmed by the sensory environment.
If we follow these theories, it becomes very understandable that autistic people often feel sensory input more intensely
It also clears up why autistic people often experience increased anxiety: if your brain is constantly creating new understandings of the world around you, rather than relying on prior expectations, life is likely to feel inherently less predictable and less certain. This could feel stressful and chaotic, ‘akin to ‘opening your sock drawer and finding a pineapple’, as Lawson and colleagues put it.
You may feel on edge, and easily emotionally triggered by things that might seem small. In an unpredictable world, it would make sense to have a preference for sameness, routine, and control, in order to feel safe.
In an unpredictable world, it would make sense to have a preference for sameness, routine, and control, in order to feel safe.
It shines a light on why social interactions and communication – which are often inherently unpredictable – may feel uncomfortable, confusing, or exhausting for autistic people.
It may also help us to understand why interpreting proprioceptive (body) signals and emotional recognition may be harder for autistic folk, because again, these may feel both unpredictable and overwhelming without a dominant top-down filtering process.
Understanding autistic strengths
The predictive processing framework also helps us understand autistic strengths. Attention to detail, deep knowledge, original thinking, hyper-empathy and deep emotion, and straightforward, honest communication all fit with a bottom-up processing style.
The popular “monotropism” theory of autism aligns too: it suggests autistic people tend to focus their attention and interests very deeply on a small number of things at a time. This means they can thrive when able to be in an “attention tunnel” to develop deep expertise for example, but it can make switching tasks, dividing attention, or coping with interruptions more challenging. For a “bottom-up” processing system that can be easily distracted or overwhelmed by external input, this type of focused attention makes complete sense.
Although research evidence supporting these theories is still in its infancy, clinically, we find this understanding can be very helpful in making sense of the autistic experience in a neuroaffirmative way - and points us towards what might help.
What this means for autistic parents
As autistic parents, these theories highlight our need for predictable routines where possible, clear communication, visual supports, and sensory accommodations to lower uncertainty and overload.
Being aware of our needs, allowing ourselves to have them, and then adapting our environments enables our strengths to shine - and helps us to connect with our children. Making similar adaptations for our children can help us create a home that supports our family’s nervous systems, and meets everyone’s needs.
Being aware of our needs, allowing ourselves to have them, and then adapting our environments enables our strengths to shine
Through this lens of bottom-up and top-down processing, autism - and ourselves, our children - can be better understood as a different balance of perception and prediction. An alternative processing style rather than a deficit, and one that thrives best in environments designed with that balance in mind.
Jo
If you are interested in hearing more about using this understanding to help prevent meltdowns and support your child to manage transitions, come along to our webinar on Tuesday 10 March for practical strategies and insights.
Authored by: Dr Jo Mueller, The Neurodiversity Practice
*References
Nb. Some of the language in older articles is not neuroaffirmative, and this does not reflect our views.
Boulter, C., Freeston, M., South, M., & Rodgers, J. (2014). Intolerance of uncertainty as a framework for understanding anxiety in children and adolescents with autism spectrum disorders. Journal of Autism and Developmental Disorders, 44(6), 1391–1402. https://doi.org/10.1007/s1080 3-013-2001-x
Cruys, S., Evers, K., Van der Hallen, R., Van Eylen, L., Boets, B., de-Wit, L., et al. (2014). Precise minds in uncertain worlds: Predic-tive coding in autism. Psychological Review, 121(4), 649–675. https://doi.org/10.1037/a0037665
Hallett, V., Mueller, J., Breese, L., Hollett, M., Beresford, B. A., Irvine, A. L., Pickles, A., Slonims, V., Scott, S., Charman, T., & Simonoff, E. (2020). Introducing ‘Predictive Parenting’: A Feasibility Study of a New Group Parenting Intervention Targeting Emotional and Behavioral Difficulties in Children with Autism Spectrum Disorder. Journal of Autism and Developmental Disorders. https://doi.org/10.1007/s10803-020-04442-2
Lawson, R. P., Mathys, C., & Rees, G. (2017). Adults with autism overestimate the volatility of the sensory environment. Nature neuroscience, 20(9), 1293–1299. https://doi.org/10.1038/nn.4615
Murray, D., Lesser, M., & Lawson, W. (2005). Attention, monotropism and the diagnostic criteria for autism. Autism, 9(2), 139-156. https://doi.org/10.1177/1362361305051398
Palmer, M., Carter Leno, V., Hallett, V., Mueller, J. M., Breese, L., Pickles, A., Slonims, V., Scott, S., Charman, T., & Simonoff, E. (2023). Effects of a Parenting Intervention for Emotional and Behavioral Problems in Young Autistic Children Under Conditions of Enhanced Uncertainty: Two-Year Follow-up of a Pilot Randomized Controlled Trial Cohort (ASTAR) During the United Kingdom COVID-19 Pandemic. Journal of the American Academy of Child and Adolescent Psychiatry, 62(5), 558–567. https://doi.org/10.1016/j.jaac.2022.09.436
Pellicano, E., & Burr, D. (2012). When the world becomes ’tooreal’: A Bayesian explanation of autistic perception. Trends in Cognitive Sciences, 16(10), 504–510. https://doi.org/10.1016/j.tics.2012.08.009.
Sinha, P., Kjelgaard, M. M., Gandhi, T. K., Tsourides, K., Cardin-aux, A. L., Pantazis, D., et al. (2014). Autism as a disorder ofprediction. Proceedings of the National Academy of Sciences of the United States of America, 111(42), 15220–15225. https://doi.org/10.1073/pnas.1416797111
