Umwelten

About Umwelten

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8 min read

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 an attempt to synthesise two kinds of knowledge about neurodiversity that are usually kept apart. There is the scientific knowledge: peer-reviewed research, theoretical frameworks, genetics, neuroimaging, systematic reviews. And there is the lived knowledge: what it is actually like to be neurodivergent, to mask, to burn out, to be diagnosed late, to navigate systems that weren’t built for you. Both are real. Neither is complete without the other. This wiki tries to weave them together.

It is curated by Andrew Hopper. It is public-facing, free to read, and will always be so.

It started as a private project, inspired by Andrej Karpathy’s LLM Wiki concept: a personal knowledge base maintained collaboratively with an AI, structured as markdown files that the AI can read, cross-reference, and help extend. I had accumulated years of reading about neurodiversity and not much structure. Building a wiki gave the knowledge a shape.

It became clear quite quickly that the result was something worth sharing. The resource I was building was the resource I couldn’t find when I started: a place where the science and the experience speak to each other, without the science dismissing the experience or the experience dismissing the science. So I made it public.

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.

The curator and the tool

I am the curator of this wiki. The editorial decisions, the perspective, the scope, what gets included and what gets cut, are mine. I bring years of reading and lived experience as a neurodivergent person.

I also use AI extensively. Claude (Anthropic) helps with research, drafting, connection-finding, and quality maintenance. This is not a disclaimer; it is the method, and it is worth explaining.

A typical page starts with me deciding what’s needed, whether it’s a gap in coverage, a topic from my work, or a question someone has raised. AI searches the literature, synthesises findings, identifies relevant reviews. 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 helps identify connections between new and existing pages, which I verify.

Why be transparent? 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 (see AI and neurodivergent minds), so hiding AI’s role would be hypocritical. And the combination of AI research capability and human editorial judgement produces broader, more thoroughly sourced content than either alone. The Karpathy wiki pattern works. Worth doing in the open.

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.

This wiki 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.

Contributing

Umwelten has one curator, but it isn’t meant to be one person’s monologue. Corrections, suggestions, references, perspectives, disagreements: all warmly welcomed. The wiki is not a traditional wiki where anyone can edit directly, but it aspires to be a braided creation: shaped over time by many contributions, woven together by editorial judgement.

If you spot an error, know a paper that should be cited, have expertise in an area the wiki covers poorly, or want to suggest a topic that’s missing, please get in touch. Every submission is reviewed, and good contributions become part of the wiki. [Direct contact details to be added.]

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