News The latest developments in autism research.
Profiles Portraits of scientists who are making a mark on autism research.
Toolbox Emerging tools and techniques that may advance autism research.
Spotted A roundup of autism papers and media mentions you may have missed.
Opinion Conversations on the science of autism research.
Viewpoint Expert opinions on trends and controversies in autism research.
Columnists Dispatches from experts on various facets of autism.
Crosstalk Debates and conversations about timely topics in autism.
Reviews Exploring the intersection of autism and the arts.
Q&A Conversations with experts about noteworthy topics in autism.
Deep Dive In-depth analysis of important topics in autism.
Special Reports Curated collections of articles on special topics in autism.
Webinars Presentations by leading experts on their latest research.
Opinion / Cross Talk

How to evaluate the ‘intense world’ paradigm?

by  /  11 February 2014


Last month, in a Viewpoint, Uta Frith and Anna Remington raised concerns about the ‘intense world theory’ of autism, an idea that has received considerable popular press lately.

The theory holds that circuits in the brains of people with autism overreact to certain stimuli in the environment, hindering their ability to integrate sensory information meaningfully. Many of the reports on sensory perception in individuals with autism align with this concept.

However, Frith and Remington argue that the theory hasn’t received enough academic scrutiny and that sensory responses in autism are highly variable, with some people underreacting to stimuli rather than overreacting. They maintain that recommending a withdrawal of sensory stimulation based on this paradigm is premature and perhaps even dangerous.

We asked five other researchers to respond to this debate — including the theory’s original framer, Henry Markram — as part of our discussion series, Cross Talk.

What do you think? Share your reactions and follow-up questions in the comments section below.

The Experts:

Henry Markram

Professor of Neuroscience, Director, Human Brain Project, École Polytechnique Fédérale de Lausanne

Sally Rogers

Professor of Psychiatry and Behavioral Sciences, University of California, Davis' MIND Institute

Matthew Belmonte

Professor of Animal Science, Colorado State University

Temple Grandin

Senior Research Associate, The Groden Center

Donald Rojas

Associate Professor of Cognitive Neuroscience, Colorado State University

A welcome debate

Bucking tradition: “Kamila Markram and I think it is great that a debate among autism researchers has finally started on this topic. At the very least, it is getting people out of their comfort zone. The traditional view is that autism is a form of mental retardation. It is a view that originated in shockingly primitive theories, and developed over more than half a century to become dogma. In our opinion, it has derailed the vast majority of research on autism and puts children with autism in grave danger.”
Copy and paste: “Many autism researchers have never worked with a child who has autism, never done a tour of duty in a school for developmentally delayed children. Many look up the symptoms in the Diagnostic and Statistical Manual of Mental Disorders or, worse, copy it from another paper — the first sentences of most papers on autism are virtually identical. When we started our research about 15 years ago, there were 625 patents for the treatment of autism, virtually all of them on ways to stimulate and shock the brain out of the depths of its retardation. There are scientists who do listen to children with autism — the work of Laurent Mottron is a wonderful example. But many listen only to the dogma.”
Intense experiences: “The theory suggests that all children who genuinely have autism experience an intense world syndrome, regardless of where they are on the spectrum. The particular nature of the intensity is unique for each child. Their world is intense because microcircuits in the brain — small groups of neurons that work together — are much more reactive and much more plastic than normal. We propose that symptoms of autism are the result of these children’s attempts to shield themselves from this intensity and the trauma they experience when they fail. In our view, researchers have overlooked this reason for why the symptoms arise. We have given a full account of the theory in the article we published in Frontiers in Human Neuroscience.”
Adverse effects: “We do not propose sensory deprivation, as some people may misinterpret. We emphasize that the current aggressive strategies of forceful enrichment and stimulation, strong rewards and punishments could have severe adverse effects. What we propose is a rich but filtered environment in which unexpected events are decreased as much as possible. It is impossible to imagine how the structure that this implies can harm any child, even if he or she is not on the autism spectrum.”
Listen: “Most importantly, autism researchers should start listening to the affected children. Every single one tells us about the overwhelming, aversive intensity of the world they experience in their daily lives. How can researchers keep ignoring what they are saying?”

Empirical evidence lacking

The over/under on arousal: “I share Professor Frith’s concerns about the theory. The over-arousal theory of autism is one of the oldest theories that have been offered, dating back into the 1960s and 1970s. Yet the largest body of research examining arousal and response to sensory stimuli in autism demonstrates that patterns of under-arousal are far more characteristic of people with autism than is over-arousal. The over-arousal theory is often used as an explanation for social avoidance, suggesting that people with autism withdraw from social contact to avoid painful over-arousal. And yet when researchers have examined social responses to others in children with autism, as in Lorna Wing’s social subtypes, social withdrawal is a pattern seen in only one subgroup consisting of a minority of children with autism.”
Social contact helps: “In terms of the idea that one should withdraw stimulation from children with autism, the intervention data suggest the opposite. The most successful interventions for young children with autism (including discrete trial teaching, Early Start Denver Model, JASPER, pivotal response training and others) add a considerable amount of social contact and interaction. Thus, I cannot think of empirical evidence from people with autism that solidly supports the theory being discussed here.”

Finding a balance

Gradual encouragement: “I am very concerned about the suggested treatment for young children with autism by withdrawing all stimulation, but I agree with Markram’s previous statement that ‘the autist perceives, feels and fears too much.’ When I was a child, loud noises hurt my ears like a dentist’s drill hitting a nerve. Scratchy clothes still bother me. A better approach is gradually encouraging the young child to tolerate more stimulation. But one must be careful not to drive a child into sensory overload where he completely shuts down.”
Variable sensitivities: “Problems with sensory oversensitivity are highly variable. One child with autism may have visual sensitivity problems, and another may have sound sensitivity. Sensory issues vary from a mild nuisance to very debilitating. Treatments for sensory problems should be a top research priority. I agree with the Markrams that sensory problems in autism can lead to an overstimulating world that is too intense. However, I do not agree with their theory explaining all the social problems in autism.”
Acknowledging advantages: “There is one part of the theory I completely agree with. I hate the deficit model when it is applied to mild autism. Milder forms of autism and Asperger can provide advantages. Half of Silicon Valley probably has mild autism, and they avoid the labels. Many kids who are just a little geeky and nerdy get an autism diagnosis in order to obtain services.”
Same child, different label: “It really bothers me to see a geeky kid labeled ‘autistic’ going nowhere due to no expectations, and then I go to a gifted conference and I see a similar geeky kid labeled gifted and he is headed toward a great career. They are the same child with different labels.”

Moderate value

Historic notion: “Though the intense world theory has been much ballyhooed as a new idea, the notion of sensory overload has, as Remington and Frith point out, been with autism for most if not all of its history. To many people with autism especially, and also to those of us who have grown up with family members who have autism or who have broader-phenotype traits ourselves, the notion seems so self-evident that its scientific and media attention seem out of proportion to its novelty. (Our own 2004 review in Molecular Psychiatry, for instance, described ‘hyper-arousal in response to sensory input’ as one potential source of ‘higher-order abnormalities’ of cognition and behavior.)”
A filtered environment: “Remington and Frith seem to construe the Markrams as advocating a withdrawal of stimulation in general, which would indeed impoverish a developing child’s environment. However, the Markrams seem to urge a filtered environment in which stimulus contingency and unpredictability are regulated to manageable levels — not so bland as to be nothing more than an occasion for repetitive behaviors, but not so intense as to be full of sound and fury.”
“Although the intense world theory conflates neural and perceptual senses of ‘intensity’ and runs a bit short on specific, testable predictions, such a filtered environment may be found to have value for some people with autism, regardless of whether it is specific to an ‘intense world’ view or whether this view even constitutes a well-framed paradigm distinct from other theoretical conceptions of autism.”

No unifying framework

Some evidence: “I agree with the Viewpoint article by Remington and Frith that the intense world theory has not received much academic scrutiny. There are, however, some pieces of supportive evidence in people that are consistent with data from valproic acid (VPA)-treated mice and rats, the animal model that inspired intense world theory.
“For example, there is some evidence for increased brain plasticity in children with autism. Additionally, there is support for a change in the balance of excitation to inhibition in autism from studies of the concentrations of glutamate and gamma-aminobutyric acid neurotransmitters, from studies of alterations in neurotransmitter receptors and from electrophysiological studies. However, these pieces of evidence are also consistent with at least one other all-encompassing theory of autism: the excitation/inhibition imbalance theory proposed by John Rubenstein and Michael Merzenich. Although connectivity changes are also noted in the VPA-exposed rats, human connectivity studies in autism offer a much messier story.”
Open questions: “The bottom line is that the intense world theory is an attractive theory for VPA-induced autism, but how well it does with the majority of autism cases is an open question. VPA exposure itself cannot explain more than a small fraction of cases of autism. Given the behavioral and genetic heterogeneity of autism, it seems highly unlikely that any one theory will provide a grand unifying framework. Intense world theory, like other theories of autism, needs to be thoroughly evaluated. To their credit, the Markrams outline a number of specific predictions and discuss the falsifiability of intense world theory in their 2010 paper in Frontiers in Human Neuroscience.”

About Cross Talk
Discussions among leading experts in the field. Submit your questions to [email protected].
  • Matthew Belmonte

    Professor Rogers’ response sets up a straw man: Nobody is suggesting a complete withdrawal of stimulation, social or otherwise. There is no essential inconsistency between the Markrams’ recommendations and the ABA, Early Start, and other behavioural strategies that Professor Rogers mentions. If anything, these approaches can be complementary as they allow novelty and unpredictability to be titrated so that the child is challenged but not overwhelmed.

    Dr Rojas seems to regard the ‘intense world’ idea as somehow in competition with Rubenstein’s and Merzenich’s notion of excitatory/inhibitory imbalance. As I have pointed out above, excitatory/inhibitory imbalance is a strong candidate mechanism (though not the only one) for the neural and perceptual intensity that the Markrams posit. Far from competing, the two notions synergise.

    Why do scientists so often assume that theoretical notions must be distinct and mutually exclusive alternatives to each other, without admitting synthesis?

  • Don Rojas

    Dr. Belmonte, it was not my intention to contrast the two ideas as mutually exclusive, although I see it can be read that way. The two theories can be viewed as complementary even though each is a distinct entity. One of the main challenges for intense world theory is the problem pointed out by Drs. Rogers and Frith, which was edited out of my own response – that is, sensory hyperarousal is seen in only one subgroup of children. Dr. Markram seems to suggest that only this type of autism is genuine in his reflection above. My response would be that it is likely to be one of many important subgroups. In this case IWT could be considered an attractive framework for that particular subgroup. In that sense, neither IWT nor excitation inhibition imbalance theory (or any other grand unification theory) provides a compelling account of the diversity of the spectrum.

  • Matthew Belmonte

    Dr Rojas, on re-reading your original comment in light of your follow-up I do now recognise in it the view that the “intense world” and skewed excitation/inhibition can be compatible and indeed complementary. I apologise for my hasty first reading which was spurred by the description of E/I as “one other all-encompassing theory.”

    We both, it seems, have encountered difficulty in saying what we want and need to say within the length limit and other editorial constraints. My first complete draft actually was three times as long as what I ended up settling on; that draft is available at “” and voices some impressions similar to yours.

  • Rose

    Will we deny the humanity of autistic children and adults? This is just outstanding. I hope the experts will listen. I’ve waited, because I thought maybe the mother was “feeding” the child’s words through facilitated communication. This convinced me that the words were probably Emma’s ( I taught at an ABA residential school where we were encouraged to think of the children as having minds of kindergarteners, or younger. Behaviorally, it was true. But even when testing showed near normal intellect, kids were still treated as their behavioral age (according the the Vineland Adaptive Behavior Scale). I think we would do well to assume competence to a much greater degree than we do. To doubt a sensitivity and presume inferior IQ or to give no regard that “unmanageable” behavior might be an attempt at self-protection due to an intensity of uncontrollable reactive responses…Even Bettleheim saw the children as reacting to a type of PTSD.

    I’m probably making no sense. I’m not that bright and have no answers. I just know what I’ve seen in teaching and raising a son. The people that have the most success are gentle and welcoming, not critical.

  • Rose

    Autism Experts. Punk Asperger’s kids figure out how to help others with their lack of empathy skills and all, and ask parent’s to chill out. Out of the mouths of babes…34,000 hits on you-tube so far, and a sensation on facebook. They ask kids to slowly break down their sensory barriers, sensory filters. Love these kids!

  • elena

    Strange example, but my autism shows up most as distrust and time delays in my emotional *comprehension apparatus*;…okay sound and touch sensitivity. Sorry to all who feel it’s been disproved, but I still bet the whole explosion started with the DES administered to pregnant women from 1938-1970’s. It was thoroughly endocrine-disrupting and epigenetic(gets passed on).

  • Seth Bittker

    Some who have diabetes get neuropathy due to neuronal damage and for this reason neuronal stimulation can be uncomfortable for some. Yet do we fundamentally think of diabetes as a disease of over stimulation of the nerves? Of course not. Do we try to address diabetes by decreasing neuronal stimulation? Why have we tried and continue to try to treat autism using these psychological approaches?

    Autism is a biochemical disease. While there are different phenotypes, there is certain biochemistry that is common: 1) dysregulated monoamine neurotransmitters, 2) Th2 skew to the immune system, 3) upregulation of neurtrophins early in life (probably causing some of the over-connectivity mentioned in this blog), 4) endothelial damage, and 5) oxidative stress.

    It seems to me that psychological effects of autism are interesting and understanding its effects can be of some utility especially in connecting and motivating those with autism. However, in my opinion much of the research effort that currently goes into these psychological studies and theories that come out of them could be much more productively directed toward biochemical studies of those with autism.

  • Brian

    I am surprised none of the people in the article were occupational therapists. The field of occupational therapy has been researching and treating sensory processing issues in general and specifically children with autism for decades. They have research from mouse models through to sensory integration and sensory based interventions that describe the different types of responses to sensory stimuli as well as methods to treat these sensory issues.

  • Patricia

    I believe there would be a lot more progress autism research if the researchers spent some time connecting and communicating with Autistic people such as Dr. Grandin. I’m glad she was one of the participants here, because she actually lives with autism. Thanks to the internet, there is a web of autistic bloggers that share their experiences. Yet, over and over it is non-autistic researchers that are guessing about what it’s like and going from there.

    I firmly believe in research, but we non-autistic people can try to postulate on it all day long and we won’t “get” it. Research that doesn’t involve the input of autistic people about their experience from the inside out, and not just our neurotypical observation/interpretation of what we think is going from the outside in, will not be accurate.

    I don’t see much of that attempt to understand the people on the spectrum that this research is all about. I’d like to see more.

  • Maren

    Readers. Check out the kind of research that is done by the Groden Center. My son with a label of PDD-NOS was so traumatized by their treatment that after 3 months we had to hospitalize him.


    I’m a single dad with a autistic 17 year old son . I agree with the theory . Joey has always been over whelmed with sound .they all demand the same amount of his attention . In a environment he’s familiar with he can focus on understanding Speach of one person . When he’s not in a familiar environment he can pretty much tune them all out . He prefers head phones to do this and often will wear them to muffle out the sound around us and not even plug them in to his iPad . People on the spectrum are so varied its difficult to generalize but I BELIVE that this theory comes close. Thanks and bless you and yours .


Log in to your Spectrum Wiki account

Email Address:



Request your Spectrum Wiki account

Spectrum Wiki is a community of researchers affiliated with an academic or research institutions. To be considered for participation, please fill out this form and a member of our team will respond to your request.


Email Address:

Title and Lab:

Area of Expertise: