When we say a child is over- or under-responsive, we’re usually describing their behaviour, not what their nervous system is actually doing. This episode pulls those apart, and the difference matters: a child who over-responds because they feel unsafe needs a completely different plan from one who over-responds because they’re curious and just can’t land. We work through valence, recovery, and how a sensory diet really earns its place.
This one came straight from your questions: over- and under-responding, sensory diets, and how arousal and autonomic state fit into all of it. Tracy makes the case that most of what we call sensory modulation is really the behavioural outcome of modulation and regulation working together, and that our field has muddled the levels of analysis, sliding between neurology and behaviour in the same breath. It’s complex, and she doesn’t pretend otherwise, but the payoff is real: when your clinical reasoning is off, your treatment goes wrong, sometimes catastrophically.
We get into the idea that sensory responses carry a valence, positive or negative, and why a defensive over-response and a curious over-response can look alike but call for opposite treatment. Cory brings it to life with his own couch-bound, slightly sick nervous system jumping at every door, and Michelle shares a giggly vestibular moment with a child who couldn’t quite recover. We finish on sensory diets, reframed for the relational, polyvagal era as something deeply social and carefully timed rather than a robot program, and on using STEP SI to build a plan that returns a child to safety over and over until it becomes their new reference point.
Lightly edited for readability. Speaker labels and chapter markers match the published episode.
Lightly edited for readability. Speaker labels and chapter markers match the published episode.
Cory: Here we go, kicking it off again for another year of the Spirited Conversations podcast. I wanted to let you all know that the new cohort for the STEP SI training has just begun, so if you’re interested, get hold of DFX as soon as you can, there’s a link in the description. And if you’ve been holding out for the SPIRIT model in cohort form, where you do the course with a group and meet live online to discuss the model together, the new cohort opens in Australian spring, and in fall for our American listeners. If the cohort form doesn’t work for you this time, don’t be discouraged, because both courses are also available all year in a self-paced version. So jump onto the link and check it out. But without further ado, let’s jump into today.
Michelle: Oh, hey guys. We’ve had lots of listener questions, so we’re going to do our usual thing and be prompted by them. They’re around sensory modulation and the language we use to describe it, which reflects how we think about it. Someone has asked about sensory modulation, over-responding and under-responding. We’ve had questions about sensory diets, how you use one and how it sits in the broader context of intervention planning. And we’ve had questions about arousal and autonomic functions and their impact on sensory modulation, and which comes first. So we’re going to try to answer a few related questions at the same time. Here we go.
Tracy: When most of us say somebody is over-responding or under-responding, we’re actually commenting on their behaviour and calling it sensory modulation. But it’s not really sensory modulation, it’s the behavioural outcome of the sensory modulation and regulatory functions working. And that’s really complicated.
Tracy: When I went back and looked at the definitions from some of the key academic people who write about this, they always blend across levels of analysis. My training in neuroscience was very specific about knowing which level you’re speaking about, which is a hard thing to do. When I reread people I admire and respect this morning, the actual definitions they use are something like, hyporesponsivity or hyperresponsivity as noted by this behavioural response. They jump from the level of the modulation response to the level of behaviour. I know the only thing we can objectively see is behaviour, we don’t have tools for measuring the rest. So in my own mind I’m thinking about the neurological accounts, from neuroscience rather than OT, and those aren’t the same as how an OT writer is writing it. That confusion is real. I was at a symposium recently where someone I admire greatly was talking about how the window of tolerance might function dynamically, but they were mixing autonomic, behavioural and sensory modulation functions without differentiating them.
Tracy: So in my own work I’ve been trying to help us all be a bit more precise and differentiate these concepts. That kind of complexity isn’t always welcome, it’s not an easy place to go. We don’t have enough science in our OT field to fully translate it yet, we’re working in a translational space between basic neuroscience and how kids develop. I’m not claiming I have a better understanding, just a different level of training that was very specific about thinking across levels of analysis. The reason we do this is because we love to talk about it, but also because it advances practice. I recently got the sweetest email from a therapist in Hong Kong whose team of twelve had decided to listen to the podcast as their continuing education. They gather as a group and chat about it, and like a lot of people they think, whoa, wait a minute, I don’t know if I know that, but it’s cool to think about.
Tracy: Where this gets tricky is that if your clinical reasoning isn’t right, you’ll do the wrong thing in treatment. If a kid is over-responsive because they’re defensive, that treatment looks different from a kid who’s over-responsive because they’re curious and engaged but can’t land their orienting into action plans and higher-level processing. That’s why we need a tool like SPIRIT, to connect the sensory process itself to how it integrates into adaptive function. The same is true with under-responding. We may under-respond to protect ourselves, and if we’re under-responding because we’re protected and in a dorsal state, the treatment is not to bombard with sensation or create bigger intensity. You can push somebody into further shutdown.
Cory: Catatonia, really shutting off from the world.
Tracy: And if you’re under-responsive because your nervous system is slowed in creating salience, but the salience is still meaningful to you, you just need it at a slower pace, that’s a different treatment plan again. So we have to differentiate based on valence. Our field is doing a disservice if we don’t start identifying sensory modulation issues based on this distinction. We can’t keep just saying over- and under-responding, because it won’t help us offer the life-changing interventions we can offer, and when we get it wrong, it can be catastrophic.
Cory: We need better definitions of the actual functions, separate from the behaviour. That’s a key thing you said earlier, that the definition involves both the neurological process and the behaviour, but the actual neurological theory isn’t embedded in the behaviour. It’s really useful to have those two as different pieces to see and evaluate.
Tracy: One thing we all struggle with, in an assessment or in therapy or even later in reflective work, is the sequence: when does sensory modulation do its work so that sensory discrimination can do its work, and what comes first? It’s a bit of a chicken-or-egg question. Sometimes you have a child who looks quite avoidant and over-responsive to sensation, and it’s hard to help them find engagement. And that could be not about sensation at all. It could be entirely about autonomic, neuroceptive processing telling them something isn’t safe. The sensation could be the unsafe thing, but it could be something else entirely. We as OTs often assume it’s sensory, when sometimes it isn’t, and when it shows up in behaviour it’s easy to code it as sensory.
Cory: I want to bring us back to the idea of whether I feel safe or not as the intervening factor around modulation. Is that right?
Tracy: If we think about neuroception as the detecting factor for safety and threat, it draws the resources of the whole system and sets the tone and state of the autonomic nervous system. So yes, but it’s not just safety and threat, it’s the activation and deactivation related to it. The state is a reflection of what neuroception detected, and neuroception draws from sensory modulation. Say there’s novelty, someone in the hallway whose footsteps you don’t recognise. Your nervous system says, something’s afoot, let’s mobilise resources to detect it. As it does that, the sensory modulation function becomes sensitised, it needs more information. And whatever you were doing, writing a letter, cooking dinner, gets put into a non-important category, and your orienting shifts toward the salient thing. That shifting happens across lots of functions, not just sensory: motor, language, memory, attention, social.
Cory: My actual experience the last couple of days, being slightly sick on the couch, lacking metabolic resources, eyes closed listening to an audiobook, any slight banging of a door, which usually doesn’t orient me at all having grown up in a pretty rambunctious loud house, I was completely jumping, orienting, what was that? Just because of the state my nervous system was in. When I’m well I have the capacity to be fluid, and my memory knows the sound of that door, I don’t need to worry about it, I can stay attuned to the audiobook. And socially, I felt irritated at anybody shutting a door, like, why are you shutting it so loud? Even though that’s exactly how it’s always shut. It was interesting how it shifts everything.
Tracy: It totally is. It also shows that the sensory over-response you were having was driven by the state. The intervening of state changed the stimulus-response formula. And it shows the sensory modulation response is not neutral, it’s valence-based. You were irritated.
Cory: Yeah.
Tracy: So we can enjoy sensation, feel soothed by it, relish it, or reject it. It has an affective tone. With the SPD nosology being retired recently, one welcome piece is that this over and under framing really isn’t the right characterisation neurologically, because at the foundation of sensory modulation there’s an affective dual coding: the valence of the sensation with its affective tone, and that’s connected to neuroception. How our sensory modulation contributes to our state is very intermingled, and you’d be hard pressed to separate it out at the level of behaviour. Am I seeing a sensory issue, autonomic, affect? You’re seeing it all. Through testing, observation and good clinical intuition you might figure out what’s driving what, so you can get to the source for good treatment. Take your couch experience, Cory, brought to a client, we might call it misophonia, really irritated by the sounds people make. Is the solution auditory? Possibly. But there’s more to it: affective and physiological regulation, getting into a ventral state so you’re not so triggerable. In a ventral state, the things triggering a negative sensory-affective experience may stop triggering it, so we’d think of it as driven by state, not sensation.
Cory: That clicks for me. I wonder about helping people who use the words over- or under-responsive update their thinking, especially if they’ve never heard of positive and negative valence.
Tracy: I have new teammates at DFX in Denver, and this came up. The first thing I suggested was to honour exactly where they’re at, because a starting spot is a good spot. If the word you’re using is over or under, use it, until the curiosity I want to plant gets more crystallised. And the first level of curiosity is: if you see a child over-responding, is it over in an approach way or an avoid way? Over in an I’m curious and can’t get enough way, or over in a that is awful and negative, defensive way?
Cory: So clever, bringing in the valence of the over or the under. You’re getting the tone of the behaviour, positive or negative.
Tracy: Exactly, because defensive over-responding is not at all the same as curious over-responding, and you’d treat them very differently.
Cory: Can you give an actual child example of the classic defensive over-response? The automatic ones that come to mind are clapping hands over ears, ripping clothing off, hating socks and shoes, fingernail cutting, haircuts. Am I missing any, Michelle?
Michelle: No, auditory and tactile defensive patterns are the classics. They impact function the most and are the hardest for educators and parents to understand.
Tracy: You could also think about defensiveness in the vestibular domain, that gravitational insecurity.
Cory: That one’s more under the radar. Kids can often work around it if they’ve got enough capacity, so parents bring me the tactile and auditory ones, and I see the vestibular gravitational issue from my clinical side, where it doesn’t always show up in everyday observations.
Michelle: Sometimes it’s less problematic because they’re more passive, they enjoy drawing and quieter play, which is easier than the on-the-go or the auditory and tactile defensiveness you can’t miss in daily life, getting dressed, travelling to school.
Cory: So that’s the classic defensive over-response, in quotation marks. But then what was the other one?
Tracy: The other one is over-responding without a negative valence. It’s the kid who is over-oriented to every salient stimulus around them, constantly, but never lands it. You see this squirrel, squirrel, squirrel quality, and it can happen visually, auditorily, tactilely, vestibularly, proprioceptively. The sequence of processing should be that we constantly surveil and detect stimulus, and as we detect it, we have an orienting response that draws us into engagement, or, if it’s negative, a defensive response. That’s the valence. Sensory modulation should then kindle regulation, so if you orient to that cool thing, it draws you in for engagement, which is the outcome of modulation. Then the praxis and discrimination functions help that engagement become purposeful and skilful. So the over-responding kid can be like a ping-pong, ping, ping, ping, but they don’t engage enough for it to become meaningful, so they just keep over-responding, instead of, I respond and I engage, I respond and I habituate. Both functions are mediated by habituation and down-regulation. If you orient, you should settle into engagement. If you have a defensive response, you should find protection and then move away from continuing to over-respond. Over-response shouldn’t continue, it should be mediated by the resourcing of the response.
Tracy: For me this brings up that the OT interpretation of sensory modulation has been too focused on the response and not enough on the whole picture of how response and recovery connect to a purpose. There’s a lot of micro-inhibition right there in the processing circuitry for a brain that does this well, and for our kids it’s not working well. Those little micro-inhibitory or facilitatory processes are sensory-affective in nature, connected to the state we’re in, which is why there’s variability based on state. As the science progresses, we need to focus much more on recovery and on those micro-processes. In treatment, what we work on is differentiating: if you’d originally have said, I see over-responsivity here, characterise it as positive or negative valence. Is it defensive, or an over-orientation they’re not turning into meaning? That paints the picture for your treatment plan. If it’s defensive, you treat through safety, uncoupling a negative response and helping it become a safe one. On the other side, you treat through engagement, building attention and participation. That’s an important distinction, and it’s the right thing for treatment planning.
Michelle: It really connects for me. When I started in paediatrics, sensory integration was the new thing, and I learned to uncover what I was seeing and why from that lens. Then DIR Floortime amped up the affective lens. And it’s only since trying to get my head around polyvagal theory that I don’t go to sensation first necessarily. My son’s eighteen, so we’ve had a DJ in the house, and this dashboard is how I view the brain, the decks. I’m not standing on the sensory integration deck, that’s one of the toggles, and I’m not on the affective toggle. I stand back as the operator and ask, what’s happening here? I had a kiddo this week doing a new little activity in a school, and they got the giggles. It was an approach, it was positive, but they couldn’t move on, couldn’t modulate or dampen down that affective and arousal piece, so they just kept giggling and looking at me. It turned into a giggle game, but it wasn’t really, she couldn’t get back together to join the rolling game we were doing. Standing back at the DJ, I could see, I think the vestibular rotary input started that cascade, and her behaviour was very affective, she got the giggles and couldn’t habituate or recover, so we couldn’t move on.
Cory: How did you recover her little nervous system?
Michelle: I stopped giggling. Initially it was contagious, because it was a surprise, well, I expected it, but I calmed myself and my affect down, dampened and dampened, stayed present, and stopped the contagion of the giggle, and she came back. She couldn’t do it again though, it was too much. The real awakening for me was that I have to get further back in the landscape and come at it from a more polyvagal approach: defence, then mobilised, deactivated, and then ask, how did that cascade, what was the domino effect, and was it primarily sensory modulation, specifically vestibular rotary, that triggered what looked like an over-responsive behavioural response, the giggle.
Tracy: A couple of things. Getting to safety may come from recovery. If you’re over-responding and things feel awful and you keep over-responding, it’s probably because your nervous system has shifted to say you’re not safe, so it keeps detecting threats, nanosecond to nanosecond. If that keeps going, eventually you might shut down. We have to view and notice that cascade as clinicians: where are they in the response-recovery cycle, in relation to their state? And we know the treatment is always safety. With the STEP SI mnemonic, you can start with sensation because it’s a powerhouse, but for a lot of people interaction is the powerhouse, and for some, predictability is, because familiar, repeated, safe patterns help create safety. So does task structure, our attitude of playfulness, our attitude of love, and offering ourselves as ventral co-regulators. The treatment is getting them back into safety so you can help them down-regulate and match their state to their response so it starts to feel right. It’s the mismatch that feels triggering. Returning to safety, getting a match, feeling seen and co-regulated and understood, then helping the body return to the rhythms of basic regulation. Knowing the different states helps, because if someone has gone all the way into shutdown, you’ll probably have to go through some activation and irritability to get back to ventral. Michelle, your example of noticing and then offering ventral-based safety without joining the sympathetic drive, and without any judgment tone, was a really important reflective moment. The STEP SI mnemonic helps you ask, what resources can I tap into, what do I know about this child and their nervous system, and what might bring them back to safety, and then how do we continue that tone of safety as we move into what we focus on next.
Cory: So that’s how we’d think about treatment planning for a kiddo with the defensive, negative-tone over-response. We go through STEP SI, figuring out the powerhouse for recovery: sensation, the task, the environment, predictability, how much playfulness, what type of interaction. Then I make a plan, what I call a recipe for that child, and the recipe is adjusted all the time, because as the state changes, the need for predictability or the intensity of sensation or the sameness of the environment will change. So with the sensory diet, the idea is that doing that repetitively and often enough, creating safety, helps develop neuroplasticity around recovery. Is that right?
Tracy: Every time we go into a question I’m like, whoa, there’s so much to talk about here.
Tracy: The foundational idea of a sensory diet is that through timing and repetition you can help the nervous system recalibrate to a set point that’s more adaptive than what’s been going on. If the difficulty is that the person keeps moving into over-response in a negative way, so they’re in a state of protection and not available, the idea is that you get in front of the arc of that messy response pattern and help re-establish a better calibration. That’s one of the really important purposes of a sensory diet. When Pat Wilbarger first thought about that terminology, it was before this deeply relational neuroscience era we’re in now. So when I provide a sensory diet, it’s almost always a sensory-social diet, with co-regulation as the guide, and sensation used as a powerhouse for the nervous system to get the regulatory input, maybe recovery, maybe a habituation signal. But I’m not going to do that out of the context of relationship. A contemporary understanding of sensory diets is that they’re deeply relational and responsive, not a robot program. If I’m working with a kiddo whose daily lived experience is moving back into dysregulation continually, why wouldn’t my plan include regularising that, so they’re not battling it constantly? If we create programming that helps the nervous system have a better reference point, through co-regulation and cues of safety, then sometimes we have powerhouse tools, like the Safe and Sound Protocol, to neurologically help the nervous system get cues that signal safety, instead of continuing to seek out information telling it things are bad. We have to flip that script and help the child find safety in the cues around them. Since we know better, we can do better.
Michelle: On sensory diets and the context we’re in now, I’ve tended not to talk about a sensory diet, I map out a STEP SI plan for families. Sensation is part of it, and I’ll be very particular: if it’s deep pressure, do they prefer a sideways cuddle, or to go under the bed with their soft toys in the dark with no talking when you enter the room. STEP SI, rather than just sensation on its own. I want families and teachers to understand the deck too, that it’s not just, I’ll give you a steamroller while I’m still teaching maths to the rest of the class. So I actually stopped using the phrase. Is that remiss of me? Am I leaning too far away from the hyperfocus on sensation, or is it putting sensation in a context that’s more appropriate to how the brain works?
Tracy: No. Being more comprehensive is clearly my thing, STEP SI helps you be far more comprehensive. Where the concept of a sensory diet gets things right is when you need really careful timing, not rigid, not doing to the child, but where you’ve carefully analysed the pattern of response and recovery: what’s the arousal or safety problem, and what’s its temporal nature across time? Then I get my plan to create the temporal organisation of that response, recovery, safety profile, so it actually recalibrates. I do that in the context of relationship, so it takes a lot of work to put together. The timing and consistent repetition, to say, this little nervous system needs inhibition, and not once a week or just when they happen to be cuddling on the couch, but on purpose, cultivated as part of daily life, without contriving or forcing it. You don’t have to call it a sensory diet, because what you’re doing is far more than that. But the theoretical construct is what you’re making decisions about, rather than just handing someone a support plan, good luck to you, here are some noise-cancelling headphones. Those things are all valuable on some level, but as therapists charged with treating this, sometimes we decide that for a window of time we’re going to construct a careful plan that makes sure the child finds safety over and over, so that becomes their new reference point.
Michelle: So it’s that on-purpose, deliberate, proactive provision of sensation through the day.
Tracy: Exactly. Then we provide a more integrative plan drawing from the other pieces of STEP SI. We have a lot of tools in our kit, and we’re figuring out what the nervous system needs as a foundation for establishing regulation that makes sense over time, not just as a coping skill or accommodation. There are different levels, and we make those decisions clinically: what does this little person need, what’s in their environment, who’s in their environment. Sometimes we can’t have a full program because there are too many limitations. I actually have a slide on this, maybe we can pop it in the show notes, showing the gradation of home programs, including the more intensive kind. The decision point for me is how restricted is this child’s ability to adapt and engage purposefully in daily life. If they really are restricted, I have a lot of tools to make sure that restriction isn’t the story of their life. To live in a space of possibility, where you can go to the store and the park, put on clothes, play at the beach, that’s a gift we can offer with concerted intervention, and then we don’t have to lighten our approach so much that we give up some of our power.
Michelle: And the broader context. Sometimes families arrive in a really vulnerable state. The child is very restricted, they can’t move into the community, the family isn’t integrated, they’re worn down. I take the family on the journey, but I say, let me do the work of understanding the child and where I can provide safety and find what’s most difficult, while I get some movement in clinic and give mum and dad or carers time to recover and some hope. There are tiny glimmers, maybe only in sessions with me, but they’re exhausted and not regulated enough yet to be a co-regulator throughout a sensory diet. Some kids find things joyful and run to it, they gesture for a steamroller or deep pressure as they lie on the floor, no work for the family to orchestrate. Other times it’s more nuanced and harder, how you offer it, what timing they’ll receive it. It’s just not the right time for the family to be laden with a sensory diet. So I think about how we co-regulate: verbally, without eye contact, a gentle sideways presence, slowing our breath rate subtly, or something more obvious where they’re asking to sit on your lap for a deep hug and a little lullaby and rocking. I think about the whole of what we can offer, and whether the family is ready, and which bits might be easier. If they’re having a harder time, offering a sensation the child can do for themselves, without the carer leading it so much, can dampen and regulate the child, which then lets the carer come in better matched, rather than two vulnerable nervous systems trying to help each other.
Michelle: So sometimes when I’m talking about a sensory diet, it’s the parents first. Okay, how do we get you regulated? What sensation works for you? Including, what music can you listen to in the car on the way home from work, before you walk in to this little cherub? What’s your regulation plan, or your safety plan, before we even start thinking about this for the child.
And that’s a wrap on today’s episode of Spirited Conversations. We hope this sparks something for you, whether it’s a new clinical idea, a fresh perspective, or just the reminder that you are definitely not alone in this work. If this conversation resonated, we would love for you to share it with anyone on their own learning journey. You can find information about the podcast on our website, and you can join us in the courses and communities the Developmental FX team have put together at developmentalfx.org. And if you’re enjoying listening, please subscribe or leave a review, it genuinely helps more people find us. Until next time, keep the conversations spirited!