If a child is relying heavily on their visual system to drive movement, the missing piece might not be where you think. In this episode we trace bilateral coordination all the way back to the vestibular system, and it changes the way you look at clinical observations you have probably been doing for years.
This one started, as so many of our best conversations do, with Michelle bringing a genuine clinical wondering. A five and a half year old, a diadochokinesis task, and a quality of movement that looked robotic no matter how much practise was offered. We took that single clinical moment and mapped it all the way through the SPIRIT model, landing somewhere we did not expect: the vestibular system as the foundational source of bilateral coordination, rhythm, and midline reference.
Tracy did what Tracy does and made the neuroscience not just accessible but genuinely exciting, and by the end of it we were all doing bicep curls at home. This is one of those episodes where we kept saying we would keep it simple, and then absolutely did not, but in the best possible way.
Lightly edited for readability. Speaker labels and chapter markers match the published episode.
Michelle: Welcome back to another episode. I think we’re up to episode 34. We are going to have a big party.
Cory: I think it’s 35.
Michelle: Is that a gold or a platinum?
Cory: I don’t know. Good question.
Michelle: It feels gold to me. It’s quite a challenge to get our three schedules lined up, and everybody to be well, and babies to be well. So we are so glad to all be here for episode 35. Today we’re going to continue some of our wonderings about the high route of S, so sensory discrimination, and the high route of A, so executive functioning and effortful control. And I’m curious about how that relates to movement. The last few episodes we’ve tried to hang around up in those higher levels of functioning, being really precise in movement, not just movement in capacity building. So what made me think about this was a little one that I’m working with. It was just this one particular example, but it is a pattern that we see regularly with some of our kiddos. So I’ll give the example.
Michelle: It’s a little one who’s around five years, six months. She is new to my caseload, but has seen an OT previously. I was doing the clinical observations of sensory integration and was looking at the alternating forearm movement. So Cory, you can say the word that I can’t wrap my tongue around.
Cory: Diadochokinesis.
Michelle: So it’s right at the start of gathering those clinical observations. I was doing one hand only, with the intention to move to both hands at the same time. And what I was noticing is that she really was looking at me. I was demonstrating the movement, and visually she was really hooked in, and was a little delayed. Some kids race and do it before I finish the demonstration. She didn’t. She really watched, and I could see a looking hard. Then I said, okay, let’s go, show me how you can do it.
Michelle: And I did keep doing it, and she was looking at my hand super intently while doing the movement. So I tried to move from that demonstration, where it was slow because she’s still young, five and a half, so slow and deliberate, to moving with a bit more rhythm and automaticity. I tried to have a little chat with her, just trying to make it move to something smoother rather than a demonstration. She stayed glued to my movement. Her eyes were fixed to my arm and she was just watching me alternate, moving from supination into pronation. She was able to do it with both hands singularly, left and right. She’s right hand dominant. For whatever reason I didn’t move on to checking how she could do it bilaterally, because it looked really effortful for her, and it appeared like she was visually constructing the movement and using executive functions to be right, driving that movement rather than an embodied sense.
Michelle: So the quality looked robotic and awkward and very task driven, even though we were doing it ten times on one side and ten times on the other side. She was getting the movement sequence right and the location right on her leg, so at about number five I was trying to see if we could get the movement to occur more freely and more embodied, with ease and flow, rather than this very assessment looking, visually driven, thoughtful drive for the movement. And so it just made me wonder.
Michelle: Do we see these kids where movement gets driven from the visual system rather than from an embodied sense? That made me think about the tactile and proprioceptive systems, that they may need more refinement and more discrimination, and this reliance on the visual system. And my question then, wondering about all of that, was: where does rhythmicity come from? I know the cerebellum smooths movement out, but where does that come from? Yes, the auditory system supports us, but how does that move into rhythm in movement, rather than an auditory sense of music, or external input driving the rhythm? How do we create our own internal rhythm? Anyway, we can have a go at mapping that to the SPIRIT model if you like. That’s what’s buzzing in my brain right now.
Tracy: I think that’s great. It would be good to have you review it, give it off the top of your wondering, and then we can talk about deepening it. And what I’m going to guide you to do as you start is this. On the SPIRIT, in the sensory discrimination functions we have over in the right hand column, there are the clusters that Dr Ayres identified and that have been repeatedly found to be valid ways of seeing the way sensory discrimination functions with different motoric capacities in particular. Very often we use this shorthand on the podcast, and in our SPIRIT community, where we say sensory discrimination for the purpose of what, and we say skilfulness, and we often also say the word praxis. So what I want to guide you to is that there’s a particular function that Dr Ayres really illuminated and brought forward as a critical function, and that is bilaterality.
Tracy: So what you’re tapping into here is that there’s a subset of coordination of our limbs in particular that is related to this bilaterality function. We’re going to explore that in this episode. But before we jump into it, I’m going to cue you that it’s usually vestibularly mediated as much as it is proprioceptively mediated. It’s really drawing heavily from vestibular function.
Tracy: This little one is about five and a half years old, and we have kids at all different ages who might show up with bilateral concerns. So one of the things we can also touch base on is how you start to see that in childhood development across the early stages. We come into the world with a body that has a front and a back and a middle, sides, and these limbs that move in particular ways. Because of that, the affordance of a body having to move has particular qualities to it that we can see pretty universally, and it tells us a lot. So it’s very cool to learn how to tune into this and think it through.
Tracy: As we think about mapping it out on the SPIRIT, starting potentially in that upper left hand part of the tool which is linked to sensory discrimination, what you were noticing was some timing issues and a lack of smoothness, and that’s going to show up in some other places on the SPIRIT too. But you were also noticing a robotic quality that doesn’t really show up on the SPIRIT. That’s a graded quality of movement that is the product of a lack of integration, I guess, in the most simple way we could look at it. We can map out the connections and see what we learn from that. So let’s do that first and then we’ll jump into unpacking it.
Michelle: Love it.
Michelle: So very initially, what jumps out, and this is what’s so fabulous about the SPIRIT, is that you can just map out the things that jump out at you first. So proprioception and tactile, the somatosensory system, that’s the thing I wanted to circle as an issue I was wondering about. How is that working in her hands, forearms, shoulders, to allow that? And that came about because she was so visually orientated to the task, and that attention didn’t wane even though she was successfully doing it. She didn’t look at her own hand. She stayed fixated on mine. Some kids see what the movement is, look at my hands to copy it, then look at their own, and then look back at my face: cool, I did it. There’s no needing of the eyes to drive the movement. So I noticed she was visually driving movement.
Michelle: Then I jumped into the process of praxis. Initially imitation, which she was able to do, and then movement planning, so the sequencing element, which I thought she was able to do, again visually and cognitively driving. Then the motor execution was the bit that had the quality that didn’t quite feel right to me, and that didn’t improve with more practice. So for me, that was the timing. The spatial quality and the temporal quality of movement is what jumped out. So I was very much in that sensory discrimination area. Vestibular didn’t come to mind, and so I can’t wait to hear more about that.
Michelle: Because she was really locked in visually, and movement planning just felt more emphasised than what I would normally see, I went over and was wondering about the executive functions that look at spatial and temporal organisation. I was thinking, how does that relate to movement? I can think more easily about how it relates to us acting out in space and in time, so us on the environment. But how does that sync up for us internally, so that we have this embodied sense of timing and space?
Michelle: And then I went down into the lower parts, so the low route of M, looking at the postural and movement capacities, at stability, mobility and the planes of movement. She was really not moving into those automatic movements. It wasn’t becoming flowing. So look, I didn’t map that out, to be really honest, but I was wondering about voluntary actions and the smoothness of that. That kind of made me go to: is that in part cerebellar, and the integration of the proprioceptive and tactile timing in the body, and rhythm in the body, and that grading of force? Classically I think about grading of force as using the right amount of muscle contraction to pick up the cup and adjust it. This was grading of force not acting on an object. It was driving movement that allowed a flowing quality to it. So I made lots of circles on my SPIRIT model, but then I was like, I can’t wait to talk to Tracy and Cory about this. As always, you put down the bits that stand out to you.
Tracy: It makes sense to me. The thing that we observe is often the limb movement, and when you see this kind of quality, it makes you logically think about proprioceptors. Any therapist might think, what is happening there, what is happening with that awareness? But in the way that Dr Ayres wrote this theory, and in the work that we do to try to deepen it, let’s look a little lower. We’re going to end up looking at the vestibular system related to this bilaterality. There is so much here.
Cory: I just need to stay organised in my thinking, because I’m having a flight of ideas. Those of you who know me, it’s like, hello, attention systems.
Michelle: And this is what happens, Trace, this is the real deal for therapists. It’s like, whoa. And then you can map out what you do know, and then have a wondering about what will I look at next session? What is the root of this? And I’m going to ask Tracy about the thing that’s missing. Where do I go? I’ve got lots of bits. Without access to you or another supervisor or mentor, I just slowly and methodically go: let me get more information about this thing that’s jumped out to me, proprioception and tactile. Then you get mentorship and it’s, oh, okay, then you can think about something else. But this is clinical reasoning, and that’s why you are flooded with: where do we go with this, where will I start, how will I explain this?
Cory: I have a story that maybe will spotlight your attentional system in a certain way, Tracy, or maybe it won’t. When you were talking about the vestibular part of this presentation, naturally I’m with you, Michelle. I didn’t automatically circle vestibular in a diadochokinesis task.
Tracy: From now on you always will.
Cory: I will. So the story is from Sheila Frick. It was in one of the many courses I took from Sheila, I can’t remember which one. She talked about planning her movement. She was in upright, and I can’t remember it word for word, but it was something along these lines: they put her in these space boots, or whatever you call them, and they hang her upside down, and they ask her to move her right hand. And she says, which one’s my right hand?
Cory: That story has always helped me remember that the vestibular system, my orientation in space, helps me. I almost need to know exactly how to plan my movement in every orientation in space. So that helped me remember that the foundation for spatially planning the movement of my own body, even if I’m not interacting with the environment, has a vestibular element to knowing my body map, if that makes sense. And I should have been circling vestibular system. I don’t know if that helps you direct your attentional system into how we’re going to unpack the vestibular bilateral function, this particular cluster that Ayres is talking about, but I threw it in there anyway.
Tracy: Absolutely. It brings up a few important features here. All of our movement patterns, once we’re imitating, and then once we’re trying to not imitate and do our own thing, all of those movement patterns require integration. What we mean by that is that integration starts to allow for the discrimination system, so this is in the high route of S, it allows that discrimination system to help us make differentiation. And differentiation is required for precision. It’s required for enough body knowing of what all the possible options are for how I might move this limb in space, to be deployed in a way that is smooth and matching, either to the groovy music that’s going on and I want to move to it, or to the activity somebody’s inviting me to participate in, whether that be a test item, let’s move your hands in this way, or let’s do a chicken dance, or whatever the millions of things are that we would do.
Tracy: So the discernment allows the system to find smoothness and ease. That’s an integrative function. But it also means that movement patterns have this funny quality to them: I’m going to do the thing that’s automatic, or I’m going to suppress the automatic to do something different, something that’s nuanced away from that.
Tracy: In basic bilateral movement patterns, they call that in phase movement. If you just clap your hands, that’s an expected in phase, easy movement pattern. But if I’m going to do a clap to you now, that’s called an antiphase movement. There are papers written on this. So bilateral movement patterns have this smooth bilaterality, where the two limbs are working in synchrony together and they’re doing the same thing as they work in synchrony together. And then there’s the higher level bilaterality: my two limbs are still synchronous, but they’re not doing the exact same thing. One is doing something and the other is doing another thing. And for that to happen, there has to be an on and then an off, an on and then an off.
Tracy: So what we’re starting to see here, and I’m going to try to keep this focused for the SPIRIT, is that there’s a proprioceptive quality to that. You can hear it in the words I’m using. But there’s also this kind of start and stop signalling. On the SPIRIT tool, we link the high route of S, sensory discrimination, with the high route of A. The reason for that is that a lot of the control and the coordination comes from the linkage with goal directedness. I want to put my limb out here in space and do a thing. So there’s always a goal directedness around that movement pattern, and that goal directedness is being held in the high route of A. As that goal directedness requires precision, the high route of A is also helping to orchestrate this connection into cerebellar processing. We can talk more about the loops of processing in a few minutes.
Tracy: So for the listening audience, what happens is that you’re deploying: I’m going to move my limb in this particular way for this particular purpose. And then, in order for me to change that movement to do an antiphase movement, I have to have a stop signal. That stop signal can be very top down, in that it might be cortical inhibition that’s happening. It can also come from the vestibular system, orchestrating that in a much more automated kind of manner.
Tracy: So we always have the low route of M, these automatic movement patterns that are available to us and that can support higher level skilfulness. Where we’re connecting here is the high route of S and the high route of A, but we’re using the resources of the low route of M, and those resources are really critical here. Where we see embodied movement patterns, it comes from these automatic patterns that we all acquire and practise. And those automatic patterns become an affordance to higher level skill in the high route of S.
Cory: Can I give an example of an automatic pattern that then becomes skilful? Stepping is a pattern. Walking is an automatic motor pattern that, once we get it, we’ve got it. But we can intentionally step up onto something as a skilful thing. Is that an example of those two? I have this pattern of walking, but I can elaborate on that pattern so it becomes a skilful thing.
Michelle: And it can become dancing. It can be elaborated.
Cory: How does it move into finesse, or having ease and flow that’s not plodding walking? Dancing is at the top end of the range of how much elaboration there is on it. If I was just walking, not thinking about walking but doing other things, and I suddenly wanted to walk in time to a rhythm, then I’d have to have this in phase, out of phase, start and stop function to make my movement match up to a rhythm or a pattern. Or if I suddenly wanted to do a double step or a skip, again I’d have to become more skilful with how I start and stop my movement and move it in or out of phase to do the actual skill I want to do.
Cory: I just want to recap, I’m not sure I captured everything. Are you saying that integration of the high route of sensory discrimination and affect allows for movement?
Tracy: Yes, and with the low route of M.
Cory: So the integration between these things allows us to intentionally manipulate some of these bilateral tasks. We have these basic motor patterns, and with the integration of some of these other systems we can use them and manipulate them in ways that become more skilful, or elaborate on movement patterns. Is that somewhat correct?
Tracy: That’s totally right.
Tracy: So now let’s take it into a couple of ways to make this as concrete as possible, so everybody listening, including us, can do a couple of things here. One thing we could do would be to take our upper extremities, our two arms, and just do this little pattern of flex, extend. That’s a much simpler pattern because we’ve practised it a billion times, even as babies within the first three months. You’ve done this a million times. So this is a bilateral homologous movement pattern that we all have available to us, and we practise it a lot.
Tracy: Now if I start to do this and I create the bilateral asymmetrical movement pattern of one arm leading, do you feel how quickly that pattern just slows down, and how much more intentional each movement within it is? We’ve taken an automatic movement pattern, bilateral flexion and extension of our upper extremities. This is just bicep flexion and extension, it’s an easy pattern.
Cory: A bicep curl.
Tracy: A bicep curl. You can do that a million times. You could do it really accurately. You can close your eyes and your arms are going to come up in the same trajectory of movement no matter what. Now if we change it to an asymmetrical bilateral movement pattern, you’re going to notice right away that you’re synchronising between the two. So this is technically an antiphase movement. What happens is that we have to coordinate the rhythm between this movement and this movement and get them to start to be in sync with each other.
Tracy: And that coordination bilaterally, between this one leading and now this one leading, starts to have a little competition in our brain power around limb awareness. So the proprioceptive load, the vestibular system. If we have rhythm generation available to us, then this is going to be far easier. But if you’re a weak rhythm generator, then this is going to start to look really…
Cory: Clunky.
Tracy: Not temporally organised. You’re also going to often see that the spatial part of it, I’m not even keeping my arm in the same orientation, you see drift of where the limb is in space, and you can start to see all kinds of errors.
Tracy: So these simple movement patterns are the standard ones that we look at in clinical observations and in looking at any soft neurological signs. If you bought any of the five books that I have on my shelf that are about how to do soft neurological sign testing, there always are these bilateral movement patterns involved. Sometimes they’re more complex, like supination and pronation. Diadochokinesis is not an expected movement. We bring our hand into supination because we need to put something in our hand, but we don’t just alternate our hand like this. It’s a bit of a novel movement pattern, far more novel than the bicep curl is, because it’s not a super well practised movement. But it’s an easily available affordance to every human, because we have muscles that allow it and our bones rotate over each other, so we have the affordance to do it. We just don’t do it a lot. So as you do it, you start to see a lot of the errors that your brain is producing when it doesn’t do these antiphase synchronous movement patterns easily.
Cory: What’s quite interesting is that with the bicep curl I was doing, the in phase bicep curling, I was doing mine out to the side just because of my microphone and everything in front of me. But as I started to be asynchronous, I actually felt the vestibular pull of trying to hold my centre while my arms were starting to go out to the side. It was pulling me, and I was like, oh, I have to activate this way, then activate that way. It wasn’t huge, but because I was paying so much attention to the sensory experience of it, I was actually noticing that I have to stabilise to allow the system to even shift to the side like that, because otherwise I can’t find my stability to even do it. It was just fascinating.
Michelle: My experience: I went forward, and because my arms were going forward, I was conscious of you two doing it. The visual input of you was impacting me, so I had to close my eyes, because it was like, whoa, I’ve got to sink into myself. It was thoughtful. Stop distracting me, you guys, I’m going to get my own rhythm happening here. And then when I found it, it was like, ah, I could open my eyes and be social and see what you guys are doing, but keep my rhythm happening. So fascinating.
Cory: I don’t know if this pulls you off track, Tracy, but I was wondering about this with the little one that you described, Michelle. She was looking so intently at your hand the entire time. You brought up this goal prediction, the high route of the affective system, and the goal directedness of movement. It’s like she didn’t have a prediction of where to direct her movement to, and she had to use your system visually to predict and direct her movement the whole time, it sounded like. So I don’t know if that brings us more deeply into this vestibular foundation of planning our movement, or these in phase and antiphase bilaterality functions.
Tracy: It totally does. And it also brings up a foundation that is a precursor to that. The precursor foundation is what you both talked about, but in a different way. And that is that we have to acquire, again with a vestibular lead and with proprioceptive, tactile and fascial qualities that support it, a midline and a reference point: the grounded sense of this is me, this is my body in space, this is the container of my body. And that container has midlines that create stability and a reference point. From that reference point, my movement patterns can proceed with all the possibilities.
Tracy: But if I don’t have that strong reference point, then I don’t know how to begin the movement. I don’t know how to synchronise the movement. I can’t start and stop the movement. And so I might have to rely on my mirror neurons and my imitative system and my thinking system to look at you and to try my best to map what you are doing onto an action that I might do. And if we do that without knowing where the movement begins and ends from, which is always a midline, then everything is going to look like it’s out of place, as if it’s happening to the person instead of being generated from the person.
Cory: Wow. That midline. For me it was moving off to the side.
Tracy: And Michelle, you didn’t use those same words, but you talked about how you lost yourself in the out there space and you had to re-reference your grounded space to find it, which was the same thing, just a different presentation.
Michelle: And that’s why she stayed locked onto me to imitate. Sometimes we see the little kiddo go, oh yeah, I know what you’re doing, and then they do it for themselves. They’ll check and look at their hands, and then look back up, and then try to go faster, or do something else, because they’re like, oh yeah, I got it, I’ll just scan and say, yeah, I do have it. I’m going to be funky with it now, or fast, or I’m going to beat you, or whatever. It moves into something else. She never did that. I’m not sure she had that embodied experience of it. I think she was very focused on getting a tick. Did I do that right?
Cory: That’s what I was wondering.
Michelle: And it didn’t become playful. She didn’t want to put her own nuance in it, to say, okay, I’ll do it this way.
Cory: Because I was thinking about the high route of A as well, Michelle. She was so invested in doing it right. The whole time she stayed with, I really want to get this right. And we’ve had you describe other children where sometimes the high route of A isn’t there, they don’t care that much about the task, they kind of copy you and just do it, yep, yep, cool, it’s done. For her, her investment in getting it right kept her so locked into the accuracy of it. But because of the differences for her in how she was integrating the information from her own body for planning, she had to use you as the thing that helped her.
Cory: I want to talk a little bit more though, Tracy, about the rhythm part, and how it links to the vestibular. I think I have the linkages in my mind of how, when we plan movement, we have to have a reference point, a midline to go away from and come back to. I can clearly and logically make the connection to the axial midline, the midline that goes down the centre of my body, from the crown of my head through my spine and core, the belly button down to my pelvis in the middle of my body. I can really embody the understanding of how the vestibular system helps me reference that place. I have a harder time finding how the vestibular system helps me reference the midlines of my limbs, out in my hands. Is it just because every slight disturbance of movement will always move my body? Can you help me make the linkages there around midline reference points and the vestibular foundations of that, when it’s not necessarily connected? Or is it?
Tracy: So part of it is that the way the vestibular system is integrating with the proprioceptive system, in the signal of this side firing, this side firing, just that alternating pattern, ends up almost being like, if we were listening to the snaps of the auditory system, the non-auditory snap, if you will, of this movement pattern has the same kind of quality to it as it ascends into the system. And part of that is that the bilateral proprioceptors are working off the vestibular spinal pathway as this primary pathway that gives rise to activation. So as the vestibular spinal pathway gives us this spinal extension, if I move a little bit anteriorly on one side, or posteriorly on the other side, the vestibular spinal pathway has to know about that to make corrections so that I don’t just fall down.
Cory: Yes, that’s what I was feeling. I was literally feeling the vestibular spinal pathway. So that makes sense. Every time I do this, in phase, not in phase, but particularly when I’m out of phase and I have these slight bilateral differences, then I have this mapping onto the vestibular spinal information that’s keeping me upright. So when I had that feeling of, oh, it’s pulling me off my centre, I knew how to still manage that midline reference and move my limbs in an asynchronous pattern.
Tracy: That’s right. And the vestibular proprioceptive information is interacting with the cerebellar information. So there’s a direct connection through the vestibular nuclei as they connect into the cerebellum. And the cerebellum is asking for information to say, it seems like coordinating this action needs a little bit more recruitment of something else. Maybe that’s a little bit more stability on the opposite side, or maybe that’s a little bit more movement into one plane or another. So we have this plane that you talked about, but we also have planes that organise the rotational spaces that we have. And that’s true of our limb movements too. We have those same planes repeated for hand movements, for upper extremity movements, for lower extremity movements. So all of those planes are mapped almost like a homunculus in the cerebellum, and the cerebellum then knows the reference point of how that is moving. A homunculus of planes of movement would be the easiest way to think about it. The system is organising those key intersections of those planes.
Cory: That makes sense, because it’s looking for the centre point of the gyroscope, the balance point. So the vestibular system is telling you, this is roughly where you are in relation to left to right activation, to stay in extension. You’ve just moved slightly this way, so let’s stay in extension. And the cerebellum is going, yeah, we’ve moved just slightly this way, but maybe we need to recruit a little bit more of this or that so that we can stabilise and maintain. So together they get you that stability. That’s why they’re always talking about the vestibular system and proprioception together.
Michelle: And the semicircular canals that are responsible for that weight shift, is that the thing that gives rise to this weight shift, if you want to call it that, of supination and pronation of the arm? Left to right weight shifting sitting on the pelvis: is that the thing that allows the timing of this to merge into your supination and pronation timing? So is it the posture that drives the timing, even though it’s really subtle?
Tracy: On some level it is, because the timing is going to come from the semicircular canals helping you organise the planes of movement, but it’s also going to come from those macular receptors in the way that they receive rhythmicity.
Tracy: The saccule in particular is almost like a rhythm and vibration detector. It’s picking up on that, and it’s helping to provide the source of that basic timing. And so the vestibular system, as it strengthens, is this background source of timing and orientation. It creates a reference point for it. And then that’s used by the motor system, but it’s also used by the auditory system, and it’s used by the way that our social motor system, as I always call it, the way that we interact with each other in this back and forth flow, is in reference to that.
Tracy: So when you experience the rhythm of another person’s movement pattern, that comes in through a lot of signals. It’s coming in obviously visually, and the way that visual motor information comes in through the embodied visual motor system, not the visual motor that we think of when we say that for constructional abilities, but bringing in visual information about the other body, and we cross modally match that. That requires the vestibular system, so that those midlines are being made sense of as I map your right hand onto my right hand, which requires this crossing of the midline literally. Then in addition to that, me seeing you do a thing inclines me to do that thing through the mirror neuron system, where those mirror neurons start to fire into my motor system from your movement system. So it’s a sensory loop into my motor circuitry. And then as that gets activated, rhythm organises it, and the cerebellum helps with this too, so that the output is in sync. There’s this idea of synchrony, and what the system does is it wants to have a match versus a mismatch.
Tracy: And this little one you were describing wasn’t feeling that embodied match or mismatch. She was manufacturing it by watching and creating it. So we can create things. I think about my own coordination system, and how there are certain things I can be quite coordinated with, and other things where, and part of this I think is more a story I told myself about myself when I was a kid, that I wasn’t a great dancer or something like that, because I was tall and I was in a class with little bodies who seemed to move a little bit more fluidly and easily than mine might have. But if I’m trying to do a dance, say I’m at a wedding reception with friends and people are doing a line dance, I have to do just what the little kid you’re telling us about is doing. I really watch, until I remember to tell myself: just feel it, and don’t think about it. And then my system frees up to do the matching that is available. But it’s always top down for me first. I feel a little stiff and silly, but I’m willing to do it anyway, because I’m always up for a good play.
Tracy: So I totally relate. We can coordinate ourselves magically from top down, and we can also coordinate ourselves more from this bottom up perspective. But when you were observing it, what you tuned into was that it was top down. And why is that, for a very little person, where it should be very available to a little five-year-old’s nervous system to be in their bottom up systems? When you see that they’re not, that tells you something.
Cory: There are so many things to chat about, because I wanted to come quickly back to the saccule. Recently I was reviewing a lot of the neuroanatomy because I did Shelly Lane’s Advanced Neuroscience Supporting Ayres Sensory Integration. When she was talking about the macular receptors being that tonic system that’s always feeding into the vestibular spinal system around maintaining extension, whereas with the semicircular canals you get activation with accelerated rotation, but you don’t always get activation. I can see how understanding the planes of movement from the reference point of the semicircular canals, having moved in planes of movement, would help me understand how to spatially move my body in different planes of movement. That made sense. But I was curious, with the saccule being a rhythm detector, is that partly just because we breathe? Every time you breathe it’s very rhythmic, and you’re constantly shifting yourself on and off your midline, even just with your breath. It’s subtle, but it’s always there. Is that partly it, or am I not even close?
Tracy: I think absolutely that’s true, but it’s also gravity. It’s just the constant. We’re never static. The gravity receptors are constantly moving, and gravity has rhythm to it. The earth has rhythm to it. We feel the ebb and flow of that and we never notice it. It’s totally subconscious to us, but it is there as a source.
Michelle: I was thinking about the auditory system, and exactly that: that we start to learn through the macular receptors that we’ve got a rhythm stimulated or affected by gravity, and we have sound, and we start to have the input from the auditory system. And very quickly I’ll go to music and nursery rhymes and prosody of voice, even with infants. So there’s a contribution from the external that helps create a rhythm. When we’re talking about hand clapping, is that an influence that allows us to create a beat, in addition to our own biological rhythms and internal systems, so that we start to know, okay, this is a beat to music, that was similar to Row, Row, Row Your Boat, or Humpty Dumpty? Does rhythm get set up through the auditory system, or is it enhanced?
Tracy: Patterns is what the system is looking for. And then those repeated patterns, especially when we make them really salient, have that quality of predictability to them. So it’s prediction, match and mismatch, that this system starts to hook itself around, and we can make that really salient. And that enhances performance most of the time.
Tracy: So even for this little one you were working with, and we don’t do this typically in testing because we’re trying to follow the generalised procedures, but if you have somebody who’s having a hard time, even if we go back to our funny little thing that we were doing: just do the easy pattern.
Michelle: Flexion and extension.
Tracy: Just feel how easy the flexion and extension is in your upper extremity limb movement. And now we’re going to start to do them in an asymmetrical way, so one is moving after the other. Just do that and you’ll feel that it’s a little harder. But now, if you just have a boom, boom, boom, boom, just do that. Feel how much easier it gets. So if you’re doing diadochokinetic supination and pronation and you do it with an audible tap, it’s a really different test than if you do it without an audible tap. Partly, if you’re doing it with an audible tap, you’re also getting a lot more tactile feedback as you do it. And so all of those multisensory supports enhance function. That’s a principle of rehabilitation that is used widely in rehab. If you go to any rehabilitation unit that’s working with people who are impacted by something, a brain injury or a stroke, you’re going to see that they’re using all of these same strategies that we would be using for the kids we’re working with, because it makes neurological sense to do that.
Cory: I was wondering about the nursery rhymes and the songs, and the ways that we support this multimodal information for the kiddos we’re working with. I was wondering about that helping with the cross modal mapping as well. We have a rhythm going and we might move our body in time to that rhythm just because it’s helping us time our body movement. But when we really make the salient rhythm of the interaction available, does that also help with this integration of cross modal mapping, for them to get motorically in sync with me? Do you know what I mean? Is that the function we’re looking at there?
Tracy: A hundred per cent. And you’re going to want to look for all those kinds of opportunities for really natural motor exchanges whenever possible when you’re working with kids that have bilateral coordination issues.
Tracy: The other thing I mentioned earlier in our conversation, and I just want to make sure that our listeners aren’t saying, but wait, what about that thing, is that we expect in this early phase of development that kids are going to move their limbs at the same time. If you want me to do something with my right hand, let me do it with my left hand too. And then I might be able to do it a little bit in a homologous pattern, where they’re doing the same thing at the same time. That’s the most low level kind of movement pattern.
Cory: When does that emerge, Tracy, roughly, age wise? Do you know?
Tracy: I don’t have exact ages. We can probably find a table of them, so that I’m not off by a few months.
Tracy: But as you notice, if you’re working on an asymmetrical or asynchronous movement pattern and it’s really hard for the child, it’s really helpful to add in: let’s back the train up and do the matching pattern first. Or take it out of the asynchronous pattern and into something more synchronous, and see what’s available to the child. If they can clap their hands but they can’t do a cross clapping pattern, that’s expected at very young ages. But by the time kids are in that five to six window, they should start to be able to pull off a lot of these bilateral patterns and have them look a little bit more available to them in a more asynchronous way. So as that emerges, you can tell a lot by dipping down into a simpler pattern and seeing what’s available there, or seeing if the priming of both sides doing this is helping. Or are they so disconnected from their body based sensations, the whole group of them, that it’s actually not that helpful to them? And then you know that the issue really is lying in this basic cluster of sensory integrative functions.
Cory: So for Michelle’s kiddo, if she wasn’t doing the standardised testing, or the way we’ve been shown to test for this one, could she have backed off and just done, tap the legs, not alternating, recruit the other side, just tap the legs? And if that then became less visually fixated, that would have given some information around whether she can embody that pattern of bilaterality, or that pattern of asynchronous rhythmic movement, or not. So it’s helpful clinically if you’re trying to reason out this bilateral capacity. Developmentally, I knew that it was always homologous to start with, as in both sides together doing the same thing at the same time. But I’ve never really broken it down with, if I was looking at it, how would I back it up? How could I grade it back so that I could figure out whether it’s there or not? So if Michelle did do this bilateral tapping with this little one and she still was visually really trying to figure that out, would that be an even bigger signal of bilateral disintegration?
Tracy: Mm-hmm.
Cory: All right. I think I’ve answered all the questions that I wrote down to make sure we went back and covered.
Cory: Every single episode we try to say we’re going to keep it simple. We’re going to try to be clear but precise, but not too complicated. I don’t know if we’ve ever succeeded at doing that. I got so much out of this conversation though. There are definitely moments where I think my concentration, I don’t know if I’m hanging on to all of this information. So for everybody listening, you’re not alone. If I ever go back and re-listen to us speaking, I’m often like, wait, what did we say? How do I make sense of that? So don’t be fooled.
Michelle: I’ve met with some wonderful OTs, lots of them, they’re all over. They’re just like, oh, Michelle, I think I’ve got most of the parts of the jigsaw puzzle, but I’m just not putting it together. It’s so hard. And this was one subtest, within a whole hour. Do you know where I pulled out? Hey Tracy, what about this? There’s an hour’s worth of stuff that’s still there. Some of it’s more clear now, and we are never going to run out of questions, because it’s constantly refining. I guess that’s the process I’ve been saying to people: it just gives rise to the next question. If I do that next time, what happens? And I might do that now about the movement system, but I also have to do it about the relational system. So this is one of a hundred questions. No wonder we get a little overwhelmed, and no wonder Cory and I, and clearly Tracy, are strong advocates of the SPIRIT and the STEPPSI. Because it helps me order all these ideas. Otherwise it just is a whole hundred questions that are not tied up yet. So we’ve tied this one up a little bit and I’ve got some ways to move forward, but I’ve got 99 other ones out there, loosey goosey.
Cory: Otherwise you’re literally like my analogy. Without having that map to help me pull the information somewhat together, it’s like I’m dropped in the middle of the densest forest and I’m pulled by the squirrel that calls me next. I am literally like, squirrel, squirrel, squirrel. Oh my god. Let’s put a thing there. Let’s do a top down strategy here. And oh my gosh, yes, let’s do a visual. There’s no foundation, there’s no grounding in my reasoning if I don’t have that map. And it’s still, I feel like I’m in the middle of, and this is probably not a good analogy for you two, but I’m in the middle of a video game where parts of the map are still grey. You know when you have unexplored parts in some video games, where you go into part of the map and it becomes illuminated and the rest of the map is still grey? So some bits of my map have had connections made and their pathways are formed, and the rest is still grey. So don’t worry about that. Just be where you are in the map and have someone help. There’s a walkthrough, and it’s sort of this podcast.
Cory: Anyway, we keep envisioning simple, clear and precise. Thank goodness for Tracy, because we would be lost. But yes, we will keep trying to provide information that hopefully is somewhat accessible to everybody, not just my obscure, strange, unique way of enjoying learning about the brain. This was good.
Tracy: I love it. And that video game analogy, that would be the Spirited Conversations podcast, and it would have a very rhythmic song in the background.
Cory: Yes. Probably some sort of Safe and Sound, or Therapeutic Listening.
Michelle: Cory’s over here like she’s got it all, Michelle.
Cory: I’m all like the Vivaldi frequencies up here.
Tracy: I’m going to provide us the bass.
Cory: Humpty Dumpty, man, that hooked me in. When you said Humpty Dumpty I was like, oh, keep with that rhythm, that feels good.
Tracy: Beautiful.
Cory: We love it so much. Thank you everyone for coming along on the journey. Let’s continue to fill in the grey areas of our map.
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 with you, we would love for you to share it with anyone you think it would resonate with, anyone on their own learning journey. And speaking of learning journeys, you can find and access any information relating to the podcast from our website, but also you can come and join us in the many different courses and communities that the wonderful Developmental FX team have put together. So head to developmentalfx.org where you can get any information you need about mentoring with any of us. And lastly, if you’re enjoying listening to us trialogue together, please just take a moment to either subscribe or just leave a review, it will genuinely help more people find us. So until next time, keep the conversations going.