The mirror image of last episode: if Episode 17 was the child who avoids movement, this is the child who never stops, the classic seeker on the go. Tracy reframes the vestibular system as the grand integrator and unpicks why under-responsive is usually the wrong label: it is either a dorsal-vagal shutdown or, more often, a lack of response from weak vestibular discrimination. The cornerstone throughout is the adaptive response: movement alone never integrated anyone, as Ayres herself said, or these kids would be the most coordinated of all.
After Tracy’s movement-avoiding young woman in Episode 17, Michelle wanted the other end of the spectrum: the busy kids, on the move, on the go, seeking movement, never sitting still. Tracy sets the foundation by framing the vestibular system as the grand integrator, the compass and North Star the touch, proprioceptive, visual and auditory systems all orient to, the source of our spatial functions (which underlie social, language, planning and sequencing), and the organiser of basic rhythmicity like the suck-swallow-breathe synchrony. There is rarely a child we see whose developmental stickiness does not touch vestibular function somewhere, which is why getting precise about it matters.
The conversation does important terminology work: we should retire under-responsive, because it is usually not a threshold problem. It is either modulation, the child tips into dorsal-vagal shutdown when movement overwhelms them and stops processing space, or it is a lack of response, weak vestibular discrimination, which is a discrimination problem, not a modulation one. They walk the clinical picture (reduced post-rotary nystagmus, off balance, weak bilateral coordination, poor ocular pursuits and saccades) as a cluster, and the treatment logic for the seeking child: anchor the movement into an adaptive function, do the math formula (vestibular plus proprioceptive should equate to body schema and spatial reasoning), and if nothing changes, check whether the input is actually adequate, because these kids often run one or two movement patterns and avoid whole parts of the system. The social and affective system is a partner too, not to force sociability but to help the experience make sense. Cory’s contained-corner case and Michelle’s week-five seeker bring it home, alongside the honest reality of reading fast-moving kids, the power of video and repeat clinical observations, going slow to go fast, and the inverse curve where learning a model briefly makes you worse before it integrates.
Lightly edited for readability. Speaker labels and chapter markers match the published episode.
Michelle: We are going to talk about vestibular integration. In episode 17 we heard from Tracy and her experience assisting a beautiful young woman who had some vestibular integration challenges. Her profile was one where she was avoiding movement, really trying to limit her experience of the vestibular system, because it was not making sense for her. As Tracy was talking, I then thought of the other end of the spectrum, the behaviours we see when the vestibular system is not integrated but the child is on the move, on the go, seeking movement, cannot sit still. The busy kids, who I think have a root in lots of things, but the vestibular system among them. After the episode I went back to the literature, and it is more common in the books we read to talk about vestibular integration when there is a lack of movement or avoiding of it, so I wanted some clarification around the other side. I also wanted to clarify some language. At the polyvagal gathering, Tracy talked about how we use under-responding and over-responding, and that we should really try not to use those terms at all, because they do not reflect what is underlying the behaviour. So when a child seems to be not registering the information from movement, how do we describe it, what language is more correct?
Cory: Those are big questions, and I was not at that gathering, so I want to understand it too.
Tracy: It starts with the beauty, power and importance of the vestibular system. In the Ayres sensory integration work, putting a lot of clarity on vestibular processing is really central to the theory. We are interested in this not just because Jean Ayres tells us to, but because if you look at a lot of basic neurological functions, both modulation and discrimination-based, the vestibular system is a key partner in ensuring things actually get integrated. In some ways the term sensory integration rings truest because of integration that is vestibularly based. The vestibular system creates a referent point for our postural system, our balance, our bilaterality, but it is also the source of information for all of our spatial functions, and our spatial functions underlie our social functions, our understanding of language, place and time, our ability to plan, organise and sequence, and a lot of higher-level cognitive capacities. It also organises the basic rhythmicity of all our systems, it sets the suck-swallow-breathe synchrony, it organises our starting and stopping, our inhibitory and initiation mechanisms. So when OTs talk about the importance of the vestibular system, it is because there is rarely a child we see where the stickiness in their development does not, on some level, touch vestibular function. And as we work on creating true integrity, activation and integration in the vestibular function, it has a really critical role in orchestrating developmental progress. Some of the terminology and categories are hard to understand for anyone, even for vestibular scientists, which is not what I am.
Cory: When I get to the assessment phase, I often am writing challenges with vestibular processing, proprioceptive processing or tactile processing in most of my reports. I remember getting to a point of, am I overseeing this? But no, the cluster of behaviours reflects this, it is just so common. The thing that changes all the time is the individual presentation of the behaviours that reflect the challenges with those underlying systems. So what you are saying is that if you can help the myriad of sensations integrate and organise with the vestibular system in a better way, that is likely to improve their function and development, not always, but when you have a vestibular-based challenge, which is pretty often, it is so integral to the other systems that you want to address it precisely.
Tracy: Yes. You could think about the vestibular system as the grand integrator. It connects to our sensory systems, to our vagal circuitry, so to basic regulation and physiological functions, and to our body schema and the envelope of somatosensation that holds our sense of our bodies in space. It connects to the visual and auditory systems in really direct and specific ways, and those systems rely on the vestibular system like a compass. If you are navigating the world, you need a referent point, a North Star, a here I am and here is where I am going. The touch system uses it that way, the proprioceptors do, the sound and visual systems do, they all use the vestibular system as that orientation point. And when they address more complex layering of processing, they pull in the partners, and the vestibular system keeps it all synchronised. So the synchrony of our systems depends on the synchrony of the relationship back to vestibular integration.
Cory: This is why the work is so hard, because we are moving between the synchrony of all those systems and trying to figure out which behaviours reflect which underlying processing challenges. I cannot just target the vestibular system, because I need to make sure it is integrating with the visual, auditory and postural systems so they can do the function of, say, looking to their social partner in space. It is this dance all the time, and also working out which system is more robust, the one that will let you start to move into the system that is not.
Michelle: Like the partners. Sometimes you can go direct to the vestibular, other times it has to be the auditory system that allows you to bring in the vestibular, which is probably a bit of what happened with the lady you worked with, the music and relationship let you bring the vestibular in. Other kids are the classic seeking kid, in their vestibular system, activating it, ready for movement, but it is not refined or purposeful. So it is, okay, you have a lot of vestibular activation that is not refined, maybe we need more proprioceptive, more tactile, more auditory, or to refine the oculomotor system to partner with the vestibular and give it better quality.
Cory: Previously, that child who moves and moves and moves, we might have said they were under-responsive to the input. What could we say now that would be more accurate?
Tracy: I want to hold us to the distinction between modulation and discrimination, and sometimes it takes a lot of discerning and observation, because we do not have great tests for much of this. If you have a child who seems under-responsive, from a modulation perspective the leading cause of under-responsivity turns out probably not to be a threshold-of-response problem. It is more likely that the person is not able to stay in a regulated state to access more typical responding, so the driver is probably that they are shifted into too much dorsal-vagal activation, a shutting off and shutting down, and people miss that all the time. You can have kids for whom moving through space is so disorienting, because of vestibular discrimination problems, that as they move they stop processing space, because the nervous system says this is too overwhelming, we are going to shut you down and protect you from the complexity. We sometimes think of that dorsal response as more of a trauma response. And in an odd way, not having enough sensory discrimination of vestibular activation creates a lack of enough information to make sense, which also keeps you from processing normally. Some of this is theoretical, because we do not have great ways of testing it, but on different tests you would see a profile: you may see no duration of nystagmus upon turning, the visual reflex that should be produced as you turn and maintain orientation of the horizontal canal. The classic way is to hold the head in 45 degrees of neck flexion, move the person in a pure rotation, and when you stop, the fluid keeps flowing and should produce a continuation of eye movements, the nystagmus response. If you are trained in the SIPT, or now the EASI, you learn how to do that, but you can also read about it, because it is a standard thing done in ENT, neurology, PT and OT clinics, outside of sensory integration. We do not own it, Dr Ayres did not invent it. So you might see a marker of weakened vestibular response, and the other core adaptive products you can test would probably be off too, balance, bilateral rhythmic coordination, ocular tracking, pursuits and saccadic eye movements, even head righting, orientation and postural righting responses, because those are all mediated by the vestibular apparatus. So in our clinical observations, even just in play, we see a cluster, not one symptom but many together, and that leads us to conclude this is based in vestibular processing. So if it is lower, it could be weak discrimination, weak vestibular activation, in which case it is not really an under-response, it is a lack of response, a classic vestibular discrimination problem, not a modulation one.
Cory: The question I had is, if going slightly more dorsal-vagal into shutdown gives them less access to discrimination, does it do the same thing if they go slightly sympathetically activated into a threat state? I am assuming you have an impact on processing in both directions, which might be why they get such varied performance day to day.
Tracy: That is exactly right. If a person gets super activated by movement and has a little sympathetic activation, one of the hallmarks is an increase in muscle tension and holding patterns in the sagittal plane, and a restriction of movements out of that plane. That also impacts vestibular processing, because as you move through space you should have the fluidity and freedom to be three-dimensionally aware of what is going on around you. Moving forward, you scan and track and see the footpath changing to a step, and you change your motor plan, pacing and timing, and notice a rail to your left you could hold. It gives us freedom of choices, fluidity and control. But if you are restricted, by a modulation issue or by not being able to integrate the details of space, movement, gait prediction and proprioception, which is more discrimination, you miss all of that. So we see our kiddos move through the world like that, and we might say, every time he gets to the stairs he grabs on and smashes his feet, he is proprioceptive seeking. That is probably true, because he is pulling in a viable partner to help with the vestibular function, but the treatment is not to give him more proprioception, it is to address the vestibular problem. So when we label things through generalised modulation labels like sensory seeking, we end up applying the treatment logic of that label, which is not exactly what the person needs.
Michelle: Thinking about discerning a behaviour and its root, your clinical signs of the vestibular system, and polyvagal mobilisation, I just put together that if the vestibular system looks robust across the cluster of tests, the behaviour could be explained by mobilisation, a more arousal-specific issue, all this moving around the clinic that is not functional or purposeful. That would explain kids who flip and flip and race through space, do a somersault, then just race and run and do not get fatigued, but it does not fill them up, they do not get satiated, they do not finish and go, whew, now I am ready for you, Michelle. So mobilisation can look like being on the go too, separate from the modulation-discrimination question.
Cory: This relates to where we started, the opposite end of the spectrum: the child who has a hard time processing vestibular information and goes into shutdown, a gravitationally insecure pattern, versus the kid who seems not to process vestibular information but goes into move-all-the-time behaviour. One thing to consider is the arousal piece to the movement. It could be the arousal that comes first, that reticular formation system driving movement, or sometimes the crashing, banging, falling and chaos lifts the arousal, so the movement is the secondary thing rather than where the drive for movement came from.
Michelle: I was wondering how to talk about this without it being confusing. If you are hypothesising it is driven by weakened vestibular processing, and they move a lot, but it does not seem to produce an adaptive response, does not let them be more adaptive in the task, then what is the treatment for that, versus the child who moves and it seems to help them learn? Can you picture those two kids?
Tracy: Focusing your clinical reasoning on the adaptive response is always the pivot point. If a child is constantly moving but the movement is not fuelling anything higher-level adaptive, the first question is, if I anchor this movement into my best guess of an adaptive function they seem to be missing, what would happen? Sometimes kids do this themselves, moving but also crashing and seeking lots of proprioceptive input or spatial cues. So you meet them there, give intensity of vestibular play and let the proprioceptive load increase at the end. Then you do the math formula: adequate vestibular processing plus proprioceptive processing should equate to beautiful body schema, wonderful spatial reasoning, or strong spatial social processing, and it should give the person a platform of choices, not that everyone has to have social interaction, but they can have a choice about it. If their brain is getting the right inputs for that formula and at the end you do not see anything changing, you back up and ask, is the right input actually going in, is it adequate and strong enough? Very often you then notice the child has one or two patterns of movement but is not activating the full vestibular apparatus, avoiding parts of it, they do not understand backward space, or what happens when their head is out of a certain position, they flip and float but are not activating the whole suite of the five paired, the ten receptors, and are not pairing it to all the possible adaptive function. So as OTs we come in and create that precision, which a child cannot create on their own.
Cory: That was Jean Ayres, I got it from her blue book. She said if movement was the thing that allowed neuroplasticity and change in the brain, then these kids would be the most integrated individuals we ever saw. But the movement itself is not the thing, you have to be able to integrate and organise it.
Tracy: So true. Then you also have the kiddo who is seeking, moving a lot and finding their way in space, but you see these micro adaptive changes that refine and refine. Those kids are easier to treat, we treat them faster, because the adaptive response is really cooking. The tricky part on the first kiddo is that we are not getting it, vestibular activation for what purpose, movement input for what purpose?
Tracy: It is the adaptive response that is the cornerstone of the intervention. If the kid cannot activate it, and you cannot figure out how to get around to activate it, that is where the problem-solving has to come from, and also that social connectedness.
Michelle: When they are on the go, I cannot keep up. Even if I try to match them and we do it together in circles, and I get really dizzy, and then taper and slow it down playfully, a lot of these kids do not care, they keep going past me and do not see it as a collaborative, connected activity. Some will not even let you in, so you do not have that social piece that is the glue to facilitate an adaptive response. They might jump off the loft onto the crash mat, and I think, let’s load proprioception even more, a tunnel at the end, a mini trampoline they jump on, but they will often avoid that and cut it out and just go and repeat their thing. So they do not readily accept the pieces I put in to test the hypothesis, does more proprioception support this, and they do not let you in to add social connection either. I find these guys tricky.
Cory: You did something interesting there, Michelle, because many of the partners we use are sensory-based, but another partner is the affective system, social engagement. The point is not to force them to be social, it is to use that system to help them make sense of the experience in a way that feels joyful. You can tell when it is supportive and working, when that is the way in for a child. I am thinking about a child I worked with who was similar to this profile. When he was in a contained space, contained visually, physically and auditorily, because he was in the top corner of the room, the partners around those pieces were reduced, the demand to process that information was less. He kind of did this himself, and when that happened he no longer flipped, and he was able to do the social. He did that himself, and I just followed his lead, and then he wanted to do the social.
Tracy: A couple of interesting things. When integration is happening for little developing kids, all this circuitry is almost automatic, in the background, supportive, allowing for other higher-level skills. When integration has not happened, the vestibular system now has to be an active thought in your mind, just like the social, spatial and language pieces, and that is also happening in the child’s brain, the automatic stuff is not automatic, and now it is drawing resource from those other things. So sometimes kids will seek containment, because it reduces the degrees of intensity they have to process and frees them up to show you a deeper or higher-level skill they want to work on. We can get stuck treating the vestibular in both directions, wanting to make sure it is well addressed, but sometimes if we just remove the degrees of freedom and contain it a little, the kiddo may show us, what I really want to work on is turn-taking with you, or this pretend game, the hide and seek where you find me and I am in this corner, that is making the world make a lot more sense to me. And now your head bobbing around is enough vestibular activation through ocular pursuit that we are getting there, you do not have to do more than that. For another kid you may have to do more. So part of it is mapping out all the vestibular functions and the foundational adaptive capacities they support. And this goes to your question, Michelle, that sometimes we have to go a little slow to go fast. When a kiddo is doing things that feel far away from the bigger adaptive thing I want to work on, if we remember to follow their lead and know the connection is there between what they are working on and that higher capacity, we can stick with them and allow that slower trajectory, instead of feeling we have to create high-level adaptation about every little thing.
Michelle: It does match what I was thinking. From Cory’s example of the container emphasising other sensory systems that help the integration, for the kiddo in my mind who is on his fifth week, I have had different hypotheses, insert myself as the player, the next week amp up the auditory partner with music and rhythm, the third week mark out the space with visuals to see if his vestibular system looks more adaptive with markers to outline space and whether he has less need to move. When the session is 40 or 50 minutes and it is run, run, run, that is where I get a bit, ugh, what am I doing? But you get glimmers and moments that look more adaptive, and that is where you settle into trusting the theories and the process, knowing it will come together, perhaps in session 23 or 43. Every week, if I have a hypothesis I am inching towards, we will get there. Those are the sessions you work hard to reflect on and reason around.
Cory: And in that, exactly as Tracy said, you go back to understanding the vestibular processing and all the senses and their adaptive responses, and the situation in front of you, and how you will pull in any of those pieces, reduce auditory processing of space, increase visual markers. Sometimes we serendipitously land on something that hits the spot and get a glimmer into their recipe. That moment with the child up on the loft was not planned, I just had the knowing that I needed to see where it would go, and later I could break down the math formula.
Michelle: Your comment, is this working, for me was, am I too scattered here, because it was a co-treat session, I was asked to support another therapist. So the tension is, is it working? I would rather reframe that to, is it working enough? The child in my mind had multi-levelled, multi-sensory integration issues, so it was not that I just had to go harder and provide more intensity to the vestibular system, it was, I need to find a component of the visual system that lets you go with that activity. Did this help enough so that we edged towards you being adaptive enough to move to the next thing? It is, did it help enough, rather than did it help.
Tracy: In our beautiful work there are lots of moments where we have to let it be enough, and really trust, and then come together for a talk session like this. We hope people find those thought partners so you can pause and think it through. Maybe you make a mind map: what is the vestibular function for this kiddo, what are the partner systems doing, and how are those resourcing the capacity I am interested in? Because our assessment tools are limited, it can lead you to questions like, have I actually looked at that discriminative function enough, have I vetted that the partner is the right or strong partner, is there a low-duration nystagmus, or, importantly, a long-duration nystagmus? In the research Dr Ayres did, and follow-up studies Shelley Mulligan in particular has published, there is an indication that with prolonged nystagmus, some of this treatment may have less efficacy. So it is important to pause and ask, do I know enough to keep trusting this is the direction to go? Most of the time it is about discerning the relationship between the integrative partners, it is not just the pure vestibular. If a kiddo is just crashing and burning and never letting anybody in, and they are not aware of themselves or others, we might need to move into the vestibular treatment when they are ready to participate in a different way, take a different tack up front and then return and revisit it. Vestibular processing can change pretty drastically as processing overall changes, so if they are not amenable now, in six months they might be, and in those months you might work more on predictability, start-and-stop routines, and having your presence be a partner. So you do not want to keep playing a record that is not working, but you also want to trust, and step back and think about what assessment data you have to know if you are on the right path, and remember the power of going slow to go fast.
Cory: You have to come back to the underlying functions and how they create the adaptive responses. If I can notice in the way a child moves which components relate to vestibular processing, I can start to observe which parts of the vestibular discrimination functions might be weaker, and adjust treatment to address that. It comes back to really knowing the system, not just the pathways, but how the input relates to the output, how moving the head changes the eyes, the proprioceptive response, the processing of self in space, and being able to identify it in function, in play, to see when it is there and when it is not. Sometimes I have a kid on a swing and suddenly their eyes go whoop, we have work to do there. I do not necessarily go and do the Astronaut Training protocol, but I know the vestibulo-ocular reflex is disrupted somehow, which will impact their ability to attend, to use their eyes, the ease with which they do things. If the swing went in a broad arc and their eyes misaligned, I would try to stay within the range where they could maintain ocular control, then grade that out and see if they could have an adaptive response around the input. That is the principle, not an exact activity.
Michelle: As much as we can, we see them in their clinical observations, but some kids resist all of this, or it is not appropriate to do these tests, so then it is just their performance and quality in the context of play. Because it is ever-changing, that observation in play is what we constantly gather and reassess, take back to our mind map. With busy kids I sometimes cannot think fast enough, I might spot it and think, that was an eye thing, note to self. Videoing these kids makes me dizzy when I watch it back, but sometimes it is so fast that it is the next session, or in the reflection itself, that you put the pieces together. I was just talking to you both today about that child who went up on the loft into the contained space, and only now I put the pieces together of why it worked. Otherwise that really adaptive moment is a bit lost on you, because in the moment, when we are truly present and avoiding getting shot at because we are the police and the baddie is coming, we have to be in it, and the inspiration comes later.
Cory: Early in my career, when it was harder to pick up those fine observations, I would do a few clinical observations at the start of a session, standing on one leg with eyes closed, a Superman prone extension, a couple of those, then my session, then repeat them at the end. Sometimes I would clearly have a difference between the start and end, right there in front of me, and the parents would say, oh, that was better, which is powerful. So sometimes I had to go back to actually doing the test, because I could not figure out in the moment exactly what was happening. It is still hard now, because I have to be really present to have good effects. I had this exact experience learning DIR: at the end you present a case vignette of what you have learned, and I remember feeling like I had an inverse curve of performance. When I did not know much about the theory, my treatment was almost better, and the more I learned, the worse I got, because I was thinking so much, stuck in my head about the steps in the developmental ladder and getting to the next thing, and my ability to meet the child got worse. Then as the knowledge integrated, I could let it go, and you end up better off than where you started, but there is that tricky process of learning.
Tracy: So when you are knowing and trusting the theory, but it is rubbing you, ugh, I do not know if I have got it, that is the time to go back and do some observations of this child in a more particular, targeted way, so you can gather what you need to answer those questions. That process is natural, and we should encourage it. It is okay to not know, it is okay to go slow, and it is okay to let it be enough of an adaptive response.
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!