Locomotor Primitives

We human beings like to think that we control our bodies, that as we command our bodies to do something, it is our sense of ourselves that acts. When we think, “Pick up that cup and drink from it”, it is our conscious sense of self, our “I”, that makes our bodies execute the sequential responses involved in drinking from a cup. If you look closely at the involved behaviors, you may notice that we have very little awareness of what actually occurs in making that behavior happen. Additionally, we are unable to describe our experience except in the broadest, most general of terms.

The distance between the conscious thought “drink some coffee” and drinking coffee is easy to witness. If when you pick up the cup the coffee sloshes around, your body acts on this visual information and corrects the forces directed through your body at the cup at about the same time that you become consciously aware that there may be a problem, perhaps even before. About the same time as your conscious mind says “Oh!”, your body has adjusted the acceleration of the cup to accommodate the sloshing. Your conscious awareness may think it solved the problem, but although aware of the issue, you’re just along for the ride to the solution.

The action of drinking from a cup, or any other movement, is performed by combining automatic movement routines which are known as Locomotor Primitives. As infants, as we learn to move, what we are really learning to do is fire up these primitives. We never really learn to walk, we just learn how to switch on or off walking. The economy of this neurological organization is obvious. If every individual had to rediscover, essentially re-invent walking, as a species we would be at a competitive disadvantage with species that could just turn walking on.

In watching animals learning to walk, it is easy to witness Locomotor Primitives at work. It is common to see animals up on their feet within a few minutes of being born. In many animals, Locomotor Primitives function fully automatically, and both direct behavior and respond to cognitive directives: drives, instincts, emotions, and feelings; without ever brushing up against any type of conscious self-awareness.

In more advanced animals, including many mammals, learning unique applications of Locomotor Primitives extends the developmental cycle, sometimes to many years. As more complex applications of these primitives are adopted, more direct control of their fully automatic functions is required. It becomes necessary to be able to jump in and edit the automatic responses. Evidence of this editing function can be found in research with spinal animals.

Spinal animals are animals in which the connection between the spinal cord and the brain has been severed. This is done to study reflex behavior, a fundamental type of Locomotor Primitive. Much of the original research was performed by Sir Charles Sherrington in the U. K. a century ago. The inhumane qualities of this research make it unacceptable by today’s standards. I am hesitant to even refer to it, however, one of Sherrington’s findings is of particular interest to this discussion. These findings were described as a behavior known as Spinal Shock.

Sherrington found that in the simpler animals, he studied there was little if any discernible difference in reflex function before and after the animal’s spinal cord was severed at the base of the skull. As the complexity of cortical functions of the species of animal he studied increased, the animals for some time would not respond to reflex stimulus, and then would. Sherrington designated the term Spinal Shock to describe this phenomenon. When Sherrington worked with higher primates, he found that their reflex functions were permanently inhibited and that they never recovered from Spinal Shock.

The point of this disturbing historical foray is that it seems that as animals evolved the ability to learn unique behaviors, they concomitantly developed the ability to consciously control Locomotor Primitives. Animals with more complex awareness and decision-making abilities additionally evolved abilities to skillfully edit and manipulate Locomotor Primitives, enabling the expression of novel and complex behaviors. Ultimately this editorial ability emerged as what we call consciously willed, or intentional movement. In Human Beings disconnecting this editorial ability from the motor system will permanently disable the motor system suggesting that we have tight control over motor function. This makes sense, as having a large cognitive capacity would be of less utility if it couldn’t implement its decisions. The long developmental cycle of Human Beings is partially dedicated to refining the interplay between consciousness and the information coming from and passing into Locomotor Primitives.

Our ability to consciously manipulate Locomotor Primitives feeds back to us the evidence and validation that we are in control of our bodies, when in fact Human Beings have a layer of consciousness overlaying more ancient locomotor systems. Our conscious awareness is essentially holding the reins of a beast upon which we are permitted to ride. The Beast Rider statement may appear supportive of the Descartesian dualistic notion of body and mind, however, it is rather just the observation that the brain is vastly complex, with functions that cannot be directly experienced, and therefore contained within our conscious sense of self. When cognitive functions are examined closely, there is no point at which the mind ends and the body begins, but rather a complex continuum of interacting functions and structures, some of which are accessible to our awareness. But I diverge from my point…

Recent research published in Science studied some of these Locomotor Primitives in a range of animals and was able to identify the same circuits at work in all the animals studied, including Human Beings. This result suggests that these primitives may have been established alongside the development of the locomotive structural architecture possibly more than several hundred million years ago. In other words, along with the genetic information for a leg, you have genetically coded information on making it work, something akin to the software that comes built into electronic hardware. The same basic circuits at work in four-legged animals have been refined and adapted by bipeds. Even though Human Beings have evolved complex uses for the arms and hands, these functions are built on Locomotor Primitives established to pull and push us around first on the ground, and then through trees.


An interesting article published in Science on work identifying movement control circuitry shared between primates, cats, rats, and Guineafowl:

Locomotor Primitives in Newborn Babies and Their Development


Paper on Drosophila locomotion published in Science

The emergence of our understanding of the reflex function and other, more complex Locomotor Primitives has broad implications for the healing arts, child development, and even the study of consciousness. Skillfully manipulating Locomotor Primitives enables the therapist to identify if and where a glitch resides in a specific structural/functional system. Additionally, it hints at methods of manipulation that bolster the operational capacity of that system. As a maladapted system is brought into better conformity with normal* functional parameters, the conscious interface with this system can mature, extending into changes in perception, cognition, and emotional regulation.

*normal in the sense of having cultural and social utility.