If you ask someone to name the senses, it will not take them long to list hearing, seeing, smelling, and tasting. Remembering the tactile sense might take a bit longer. These are the classic definition of the senses. In the literature on child development, as a group, they are referred to as the “exteroception” senses since they inform us of the world around us. NOTE: The categorization of the senses is evolving and still in flux.
Over the past couple of decades, due mainly to the emerging field of sensory integration, early childhood development has paid increasing attention to the body’s internal senses. In particular, the senses of proprioception and vestibular system. Proprioception is the muscle and joint sense. It allows you, for example, to know where your hand is when you can’t see it. In my work as a play systems designer, I create environments with lots of complex climbing challenges to help develop this system.
The vestibular system includes the organs of the inner ear and their connections to the eyes and is responsible for balance and eye-tracking. On the playground, we add balance beams, slack ropes, and spinners for children to use.
The vestibular and proprioceptive senses are sometimes included in exteroception or as part of the “interoception” system. The primary use of the term interoception is for the sense of our organs. Hunger, breath, heart rate, pain, and elimination are all part of this sense.
The organ-sensing aspect of interoception is different from all other senses in its subtlety. We often have to ask children, “How do you feel?” to draw their attention to their internal conditions. This lack of discernment on the part of children is actually one of parent’s biggest challenges. Let’s look at an example in detail.
Parents often have trouble with fussy children. They generally see this as indicative of an internal need and offer water and food. When these options fail, they will conclude that their child needs a nap, but getting this to happen can be a challenge. The recommended method for getting a child to calm down is rocking, which stimulates the vestibular system and, when done slowly, is often sufficient. Using a pacifier, what a great name, and swaddling, both of which stimulate the tactile system, are also great aids. When none of these are effective, the last resort is to rock the baby while standing up. Why would this approach be practical?
The new information coming out from neuroscience, especially with the advent of fMRI technology, as well as studies in evolutionary biology are adding tremendous new insights on child development. When it comes to the efficacy of standing and rocking, it turns out that infant primates have a build-in response to being carried that causes them to become still. The reason for this is that the mother needs to be able to move about, and more importantly, flee if needed, and their infant must be inactive for safety. We see the same in other animals. For example, you can move a unrulily cat by picking them up by the scruff of their neck for the same reason.
Young primates cling to their mothers a great deal of the time. This close bond leads to some amazing interactions. For example, it is not uncommon to see a mother hold her child away when they need to eliminate. This behavior is not only true of monkeys and apes but also humans in hunter-gatherer societies. This intimate bond that allows the mother to sense the child’s interoception state is normal. What is not normal is the general lack of this maternal connection in modern society. It is no wonder that parents have a challenge when it comes to potty training as they have not had the chance to set their child down on the potty just at the right moment, so the child makes the natural association.
I have dedicated my career to providing environments that support the development of the vestibular and proprioceptive systems. It is now time to look at the organs of the interoceptive system.
Watch this space for more soon.