Once again I find myself drawn to the Dave Matthews Band, this time as an association to The Spaces Between Us: A Story of Neuroscience, Evolution, and Human Nature, a new book by Professor of Neuroscience and Psychology at Princeton, Michael Graziano.
From the inside jacket liner to Professor Graziano’s book: “A six year-old child has an inborn difficulty processing the buffer zone within a few feet of his body. The consequences reach into every aspect of his life – walking without bumping into things, using a fork, writing and reading, but especially social interaction.” The six year-old child turns out to be Michael Graziano’s son, and we will return to his story in a moment.
Graziano is a researcher who experiments principally with monkeys, best known for his work on peripersonal neurons, the neuronal correlates of peripersonal space. On page 9, he lays the groundwork for the social implications of what we might call periocular space: “They say the eyes are the windows to the soul. When you think about it though, the eyeballs themselves aren’t really the windows. If you could look at a pair of eyeballs minus the rest of the face, you wouldn’t learn much. I suppose you’d learn where the eyes are looking and how dilated the pupils are, information indicative of the person’s state of mind. But the broadband on that information is limited. Really, for reading another person, everything surrounding the eyes matters most. The windows to the soul are the eyelids that can narrow skeptically or open wide, the eyebrows that move and shape expressively, the sly wrinkles at the outer corners or on the bridge of the nose, the upward bunching of the cheeks – the many tensions and relaxations rioting around the center.”
The story heats up on page 37 when Graziano discuss the near space network. Neurons that monitor the space around the body through touch and vision can be found in at least three other brain areas in addition to the putamen, two subregions in the parietal lobe (7b and VIP), and the polysensory zone of the motor cortex. Although he says nothing in his book about binocular vision and eye movements, others such as Clery et al have mapped out the near space network with regard to peripersonal space coding, and the near space network in relation to vergence tuning and oculomotor structures.
It’s appropriate to interject a reminder here about the genius of optometrist Fred Brock in this regard. Although he didn’t label it as such, Brock intuited key regions of space that he partitioned through a seemingly simple tool of a string with three beads.
It would be simplistic to think of the Brock String merely in terms of “physiological diplopia” or as an elegant “anti-suppression” feedback tool. True, it can be these things. But equally if not more important is the ability to for the patient to connect the projection of the eyes through a volume of space that has become discontinuous or fragmented. That is one reason, I believe, why convergence in often compromised in patients with developmental disabilities or acquired brain injury. Not because there is anything fundamentally wrong with eye muscle properties, but because of a fundamental deficiency in the patient’s use of the near space neuronal network.
Back to the story of Graziano’s son, which he saves for the final chapter, The Personal Dimension of Personal Space. Graziano has previously shared this heart-wrenching saga as an essay in Aeon, and at the time referred to the condition as apraxia rather than dyspraxia. People seem to use the terms interchangeably, sometimes speaking of praxis in general. Others, particulalriy in the UK, prefer Developmental Coordination Disorder or DCD to describe the disability. (I cited some of the terminology issues with dyspraxia awhile back.) It is this step outside the laboratory that makes what Graziano has to say so compelling to parents and clinicians alike as he opens the final chapter:
“I thought I’d share a difficult experience my family had a few years ago. It illustrates almost every important point I want to make about personal space. When the ability to process personal space is compromised, almost everything else is affected – sometimes in weird, unexpected, even devastating ways. It’s not just a matter of academic science, of monitoring neurons and measuring reaction times. Personal space is a real thing that impacts real lives culturally, socially, and emotionally … I’ll try not to get too high up on my soapbox about the condition called dyspraxia. It’s sometimes called the hidden disability because so few people know about it and so few people – teachers, parents, or children – can see it even when it’s standing right in front of them crashing into things. Dyspraxia is a gap between what you know in your head and what you can do in the physical world. It’s a difficulty with movement control, especially when learning new complex skills.”
Regarding his son, Graziano continues: “We now know that he couldn’t build a good spatial foundation from the core of his body. Personal space, after all, is an outward extension of the body schema. Without that anchor point in his body, he couldn’t build up a proper understanding of the space around him or coordinate movements and postures of his arms and hands within that space. He lacked the foundation on which the more delicate writing movements are normally built. He couldn’t properly wrap his peripersonal space around a pencil in his hand. And he couldn’t judge the spacing on a page. For example, other children start writing at the top left margin. My son may have learned the concept, but in practice he would plop the first mark down anywhere, sometimes in the center, sometimes on the right side of the page. He tended to neglect the left side of the page, a common spatial disturbance in dyspraxia sometimes called pseudo-neglect. True clinical neglect is when specific damage to the brain such as a stroke, erases a persona’s ability to orient to one side of space It’s stark. But children can develop a more subtle pseudo-neglect if they can’t fully tune up their mechanisms for processing space.”
Powerful stuff. A new form of “pseudo-CI”. Not because the principal problem is with accommodation, but because of pseudo-neglect due to disorganization of the near space. As Graziano notes, you may understand the concept of near personal space; but you just can’t see it very well. And as Graziano emphasizes you may be able to deal with near space under certain circumstances, but it requires an intense amount of effort and concentration, “like a drunk person trying to pass a sobriety test”. This contributes to the maddening inconsistency of performance, and the admonition that a child could achieve if he simply tried harder or learned more self-discipline. Grazianos’ son was expelled from school, and suffered what Michael refers to as a form of post-traumatic stress disorder over the anxieties he faced. Ironically his stress was not exacerbated by bullies in the schoolyard, but by the bullying of adults in the educational system in New Jersey who thought they knew it all. It took the hiring of an advocacy attorney, independent evaluations by experts, and a lawsuit to provide the right type of school environment and support programs enabling his son to thrive.
In Graziano’s son’s case, an approach emphasizing vestibular-based therapy is what finally seemed to result in a breakthrough. In particular, Graziano credits astronaut training as he observes: “The astronaut training seemed to put a missing piece in place. Suddenly he began to understand the space around him. The other therapies, that had spun their wheels in the mud for two years, now suddenly caught traction and began to work … We bought a trampoline, a welcome addition to the therapy because it was more a game than a chore. Our pediatrician looked at us squint-eyed and said, “Are you serious? You know that, as a pediatrician, I’m not supposed to sanction that”.
And as Graziano concludes: “Personal space has a hidden impact on education. Mathematics, the most abstract branch of human thought, grows developmentally out of spatial processing … How can you learn to read and write if you have trouble with the spatial relationships of letters, words, or even the whole darn book with respect to yourself? All the basics of education are at risk of derailment.”