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CHAPTER 15

The Basis for BHET

QUESTIONS RELATED TO the complexity of brain development, organization, and disruption following an injury have haunted me throughout my career. I began exploring these concepts using information from a biology class I took at Andrews University called “The Evolution of Behavior.” Dr. Stout, an animal behaviorist, helped us understand the development of the nervous system from lower forms that perform simple stereotypical functions to a more complex brain that allows us to perform elaborate behaviors that make us truly human, over the many years of evolution. The term used in science for this type of evolution is called phylogeny. Another class in embryology and genetics, under a different professor also provided me the basis to understand human growth and development, starting from the sperm and the egg uniting to develop into a sophisticated well-organized nervous system. This nervous system’s embryological development with the noted anatomical, structural, and physiologic functioning linked to behavioral development is the concept of ontogeny.

It was then that I understood that the human nervous system was hierarchically organized, having evolved over time to perform very complex and sophisticated functions. I was moved by this issue and applied the concepts of phylogeny and ontogeny to help shape the BHET Method.

Ironically, from the embryological ontogeny and evolutional phylogeny perspectives, the structural and physiological development of the nervous system organization starts with the most primitive “tail behavior” and gradually progresses to the most sophisticated “head behavior.” Lower life forms developed with nervous systems following tail behaviors that are simple, predictable, and stereotypical (simple functional routines performed without variation and much thought). These tail behaviors allow the organisms to survive in the environment where they exist. Over time, those simple organisms use primitive, well-established genetically coded behaviors, developed over millions of years through multiple generations to function and have adopted “association type learned behavior.” This associate type of learned behavior has been developed as a result of repeated exposure to an either hostile or friendly environment where an organism learned over time to adopt a fixed behavior pattern in association with the presented stimulus. Associate learning is one of the most powerful forms of learning in nature. Once learned, it becomes extremely difficult to unlearn (see chapter #43 for more on this).

Tail behavior can be seen in the most complex forms of life but is generally suppressed by the more sophisticated head behavior. Such tail behavior can be observed in humans in the period around birth, prior to the complete development of their nervous system. Babies display primitive tail behavior that allows them to survive in the uterus. Pediatric neurologists and pediatricians spend a considerable period of their careers monitoring such tail behaviors, as the suppression of such behaviors represents the maturity of the nervous system while the retention of tail behaviors in humans can mean developmental delays or injury.

I recall my pediatric neurology professor saying that these primitive behaviors comprising tail behavior are inhibited by higher centers in the brain as these centers become mature. The failure to inhibit such tail behavior indicates a malfunction in the higher centers. The frontal lobe represents the highest center of head behaviors and functions as the command center for most of the activities that make us truly human. When the frontal lobes fail to work properly, tail behavior returns, hence the name frontal release signs. A return of tail behavior after it has been inhibited highlights a new injury to the nervous system. Primitive tail behavior seen in adults can occur after the higher cortical centers are damaged and no longer can inhibit or control lower tail centers. Individuals with an injury to the frontal lobe in the brain can see a return of the primitive frontal release signs, such as the suck reflex, grasp reflex, and rooting reflex. In TBI context, the frontal lobe is one the most common parts of the brain to be injured due to its location in the front of the head. It is subjected to many forces in, say, a motor vehicle accident and in many sporting activities.

Frontal release signs are now used in the profession to grossly assess the presence of injury in the frontal lobe and notates a disruption in the structural and physiological functioning of the brain. Injury to the frontal lobes represents some of the highest forms of brain hierarchical disorganization.

Table # 9 – Examples of “Tail” behaviors

Reflexes	Description	Name
Suck reflex seen in children	This is seen when an object such as a pacifier or mothers’ breast or the nipple from a bottle used for feeding is placed in a baby’s mouth, invoking a sucking response. This reflex is a primitive reflex seen in animals to allow for the young to get food from the mother, as the animal is not yet in a position to seek out its own food. Over many years, early sucking has come to be associated with animal survival.	Frontal release sign
Grasp reflex	This is used to maintain balance when holding on to objects to maintain posture. Babies grab objects automatically when placed in their hands. In fact, this reflex is so powerful that an adult with their two index fingers can lift a child with the child grasping the two index fingers of the adult.	Frontal release sign
Rooting reflexes	Stroking the corner of the face causes the head and neck to move towards the area being stroked.	Frontal release sign
Babinski reflexes	This refers to the fanning of the toes when the bottom of the feet is stroked. This reflex is inhibited when a child starts to stand and walk.	Upper motor neuron sign

Humans have achieved the highest form of power in nature due to the development of head behavior through the processes of phylogeny (how we evolve over time and generations) and ontogeny (how we evolve from conception through adulthood and to our death). This head behavior allows us to develop social order, build family units, communicate at the highest level, survive, and protect ourselves. While some tail behavior can integrate with more complicated behaviors from the higher centers, without the presence of such higher centers, our basis for being human does not exist. A patient in a comatose or vegetative state generally exhibits tail behavior only and not head behavior. A coma or vegetative state occurs when their head behavior becomes absent to the point that there is little to no control over tail behavior. Complete brain death occurs when there is no tail behavior or head behavior, starting from the level of the brain stem up to the cerebral cortex.