Autism

Proprioception and the Brain

by Kristina Chew

category: Science

Published July 07, 2009 @ 02:26PM PT

Interesting study (which Dora just posted on) on whether there's a connection between "deficits in motor control, imitation and social function" in autistic children and a "dysfunction in the neural basis of representing internal models of action" in the July 5th Nature Neuroscience. The abstract, quoted in full:

Representation of internal models of action in the autistic brain

Children with autism spectrum disorder (ASD) have deficits in motor control, imitation and social function. Does a dysfunction in the neural basis of representing internal models of action contribute to these problems? We measured patterns of generalization as children learned to control a novel tool and found that the autistic brain built a stronger than normal association between self-generated motor commands and proprioceptive feedback; furthermore, the greater the reliance on proprioception, the greater the child's impairments in social function and imitation.

Proprioception includes, according to a 1994 Journal of Neurophysiology study, "all somatosensory information related to joint posture and kinematics." I've mostly heard the word used by occupational therapists in relation to sensory integration. A Wrong Planet forum refers to proprioception in terms of "body awareness"; a website on sensory processing disorder suggests that "proprioceptive dysfunction" is the "REAL Reason He Keeps Crashing, Jumping, Tripping, Falling, Writing Too Dark, And Breaking Things!".

The Nature Neuroscience study interests me as it suggests what might be happening, or not happening, with Charlie thinking about doing some action, trying to get his hand or leg or body part to do it, and something signals getting "crossed." It's hard to know what certain motor actions seem like to him in his mind, with his limited language: We tried for years to show Charlie to tie a knot with his shoelaces and finally set that task aside (he prefers slip-on shoes anyways). I often had the sense that he just didn't know where to position his fingers and how to move them to form the knot, and no amount of pictures or photos seemed to help (they just made him more frustrated).

Jim and I have long noted that Charlie struggles to coordinate his body's motor (gross and fine) movements with our and other's verbal directions. We've also long observed that, even when Charlie is giving every indication of wanting to do some motor activity (holding a pencil, using a bat to hit a ball off a tee, climbing down a ladder), he often has balked, asked for help, refused to do it, or moved slowly and fitfully. He sometimes uses too much force when touching or patting someone or something. Lying face down with his hands under his body is still a position of comfort for him, and he still (though not nearly as much as he used to) wraps himself tightly in a big fleece blanket for comfort.

As Charlie is currently so athletic and at ease on his bike, it's easy to forget, if not disbelieve, that he might struggle with other aspects of mind-body and physical coordination, and in ways that are invisible, until you look a little more closely.