Umwelten

About Umwelten

meta

8 min read

About Umwelten

The name

In 1909, Jakob von Uexküll, a German-Estonian biologist, introduced an idea that reshaped how scientists think about perception. He called it Umwelt: the perceptual world unique to each organism, constructed from what its particular nervous system can detect and how it processes that information.

A tick, Uexküll observed, perceives almost nothing of the rich world a human inhabits. Its umwelt is built from three signals: the smell of butyric acid (indicating a warm-blooded animal), the temperature of skin (confirming contact), and the tactile sensation of finding a hairless patch to feed. Colour, sound, language, the passage of seasons do not exist in the tick’s world. Not because it’s too simple to appreciate them, but because its nervous system cannot detect them.

Every organism has its own umwelt. A bat navigates through echolocation, its world sculpted in sound. A honeybee sees ultraviolet patterns invisible to humans. None of these worlds is better or worse. They are different realities, constructed by different nervous systems.

The concept applies to human neurodiversity. An autistic person’s umwelt differs from a neurotypical person’s. The fluorescent light that a neurotypical brain filters out becomes a strobing assault. The background hum of a café that one brain treats as irrelevant becomes an unignorable wall of sound. The seam of a sock that most people stop noticing after thirty seconds continues to scrape across skin with the same intensity hour after hour.

But the umwelt extends well beyond the external senses. Once a nervous system is complex enough, the perceptual world reaches inward too. An autistic person’s umwelt includes a different relationship to their own body signals: interoception that may be muted, absent, or overwhelming. A different social world, where attention distributes differently across a room of people, where conversation works better one-to-one than in groups, where deep shared interest is the natural mode of connection rather than small talk. A different temporal experience, where transitions between activities are genuinely costly and the monotropic pull of focused attention reshapes how time feels. A different emotional landscape, where feelings may arrive without labels, where regulation depends on movement and sensory input rather than talking things through.

None of this is deficit. These are different ways of being in the world, constructed by different nervous systems, as real and as valid as any other.

Umwelten is the German plural. This wiki is about multiple perceptual worlds, not just one.

What this is

Umwelten is a personal encyclopedia of neurodiversity, maintained by Andrew Hopper. It covers sensory processing, autism, ADHD, and intellectual disability. It is public-facing, free to read, and will always be so.

It aims to be what I couldn’t find when I started working in this space: a structured, evidence-based resource that takes the neurodivergent perspective seriously, is honest about what the evidence supports and what it doesn’t, and is useful to autistic people, families, carers, teachers, researchers, and anyone wanting to understand how different brains inhabit different worlds.

The wiki currently covers the eight sensory systems in depth, along with practice and strategies assessed against the evidence, approaches and interventions each critically examined, key figures in the field, contested territory where evidence and practice collide, the intersection of AI and neurodivergent minds, and the science from genetics to predictive processing. Evidence gaps are documented as carefully as findings.

The perspective

Umwelten has a viewpoint, and is honest about what that viewpoint is.

The wiki speaks from the neurodivergent perspective, not about neurodivergent people as objects of study. Neurological differences are differences, not deficits. Challenges arise from mismatch between the person and their environment, not from the person being broken. This is the position best supported by evidence on masking, mental health outcomes, and the social model of disability.

Every claim traces to its source and evidence level. Where evidence is weak, the wiki says so. Where it is contested, the wiki presents the contest. Where gaps exist, the wiki documents them. Evidence gap pages are as valuable as topic overviews.

Neurodiversity research has significant evidence gaps. Much practitioner work has not been rigorously tested. Much widely adopted practice is weakly evidenced. The wiki does not pretend otherwise.

The wiki takes positions on contested topics (ABA, PBS, polyvagal theory, Zones of Regulation) while presenting evidence for each position and explaining who disagrees and why. Being neurodiversity-affirming means being critical of systems and frameworks, not of the people those systems claim to serve.

British English throughout, because that’s how I write.

How it is made

Umwelten is built with substantial AI assistance. That is a statement of method, not a disclaimer.

The wiki is written in markdown, managed in Obsidian, and published via Quartz as a static website. AI assistance comes primarily from Claude (Anthropic), used for research, drafting, connection-finding, and quality maintenance.

A typical page follows a path something like this. I decide what’s needed, whether it’s a gap in coverage, a topic from my work, or a question someone has asked. AI does the initial research: searching the literature, synthesising findings, identifying relevant reviews and meta-analyses. I check the research for relevance and accuracy. AI drafts the page following the wiki’s structure and editorial stance. I then review, edit, and approve: checking evidence claims, adjusting tone, adding context from my own knowledge, cutting what doesn’t work, and publishing only what I’m willing to put my name on. Some pages go out close to the AI draft. Others are substantially rewritten. AI then helps identify connections between new and existing pages, which I verify.

Why be transparent about this? Most published content using AI assistance doesn’t say so, which is a problem in knowledge resources where trust matters. This wiki also covers the intersection of AI and neurodivergent minds, so it would be hypocritical to hide AI’s role in writing that discussion (see AI and neurodivergent minds). And the combination of AI research capability and human editorial judgement produces broader, more thoroughly sourced content than either alone. Worth doing in the open.

The AI does not decide what topics the wiki covers, set the editorial stance, or publish without review. It has no access to personal data. The wiki’s perspective is mine. The AI helps me build it.

Origins

Some of this wiki’s foundational content, particularly the Dutch sensory processing frameworks (prikkelbalans, prikkeltaal, prikkelprofiel) and research on sensory processing in autism with intellectual disability, draws on a four-year participatory action research project called De Sensatie van een Goed Leven (The Sensation of a Good Life) at the University Medical Centre Groningen. See De Sensatie van een Goed Leven for that project’s history.

Why Uexküll matters

Jakob von Uexküll was not thinking about autism when he described the tick’s umwelt. The implications of his concept go further than metaphor.

His insight was that there is no single objective world all organisms perceive more or less accurately. There are only umwelten: perceptual worlds, each real to the organism that inhabits it, each constructed from the intersection of a nervous system and an environment.

The dominant framework for understanding autism has historically assumed one correct umwelt, the neurotypical one, and measured autistic experience as a deviation from it. Autistic people “fail” to filter background noise, “overreact” to light touch, “miss” social cues, as if neurotypical functioning were the standard. Uexküll’s framework dissolves that assumption. There is no standard umwelt. There are different umwelten, each built by a different nervous system, each with its own thresholds, filtering, precision weighting. The autistic umwelt is not a degraded version of the neurotypical one. It is a different world: detail is vivid and filtering is effortful, patterns are salient and noise overwhelming, the body’s internal signals may be faint, absent, or intensely amplified.

This changes how we think about support, environments, education, and technology for neurodivergent people. The goal is not to make autistic people perceive the world the way neurotypical people do, but to build a world that accommodates different ways of perceiving.

Acknowledgements

This wiki draws on the work of the SGL research project at UMCG, led by Jeanet Landsman-Dijkstra and Andrea Fokkens. The Dutch sensory processing frameworks documented here were developed through that project’s participatory research. I am grateful for the foundation they built. The work is now hosted under Stichting Bruggenmakers, and I’m grateful for their support.

The wiki also benefits from the work of every researcher, clinician, autistic self-advocate, and carer whose knowledge it tries to synthesise. They are credited in the pages that draw on their work.

Contact

If you find an error, want to suggest a topic, or have relevant expertise to share, I’d like to hear from you. You can submit a suggestion through the wiki, or reach me directly. [Contact details to be added.]

Graph View

Backlinks