In the process of conducting research in support of the TBI Proposal, I found a number of web resources not previously encountered. One of these resources provided information on the importance of meta-cognitive activity as a therapeutic response to TBI. I described this briefly in the prior post. Another resource described how the brain works.
While I have found much new information, I have had considerable difficulty absorbing it. Much of it was written for a medical audience and presents difficulties to me as a layman unfamiliar with all of the medical terminology (I was once employed in an EMT role but much of this new information is well beyond my limited knowledge). When I attempt to read this new information, I quickly become fatigued. Once a first reading is complete, it is necessary to undertake second and third readings to fully understand the information presented.
One resource was specifically targeted to a lay audience. Titled “A Fairly Simple Introduction To How The Brain Works For Survivors Of Head Injuries And Their Families” (hereafter HBW) the document delivers a lay understanding of brain function. I have read it three times now and I still have not fully grasped all of its content. This post is intended to assist me in extracting information which directly applies to my injury. I expect the process of drafting this post will assist me in coming to a better understanding of the material. I write this as a caution. Since I am undertaking this post as an exercise in understanding, please be aware that my interpretation may be incorrect. This post will likely need to be altered as my comprehension of the material improves.
Localization versus Pathways
The first topic of interest is a discussion of “Old Ideas About the Brain.” This discusses the theory of localization, the idea that discrete areas of the brain are responsible for specific functions, and behaviours.
Under localization theory, damage to a specific region of the brain results in an irreparable injury and a loss of function which cannot be repaired. If you loose your left arm, no other extension of the body can be pressed into service to replace the functions of the missing limb. Similarly, if you loose, or severely damage, a specific functional locality within the brain, no other locality will be able to substitute and replace that lost function. Brain damage is seen as cumulative and the functional effects of brain injury will endure for the lifetime of the victim. This is not a welcome thought. It is certainly not what I want to hear as I have been struggling to retain confidence in my ability to exert myself to overcome my injury. My bouts of depression arise when I come to believe that no amount of effort on my part will result in positive change. This information is very, very difficult to accept.
HBW introduces another worrisome fact: “Our research provides plenty of evidence that people with head injuries earn lower scores on I.Q, tests and particularly low scores on certain tests of memory and attention, even many years after the injury.” The paper indicates long term negative implications for both earning capacity and for a successful return to a prior occupational role.
The HBW paper then introduces a new theory of brain function, one that supplants the localization theory. In this new understanding of brain function, the pathways that connect various brain regions are deemed to be more critical than the brain regions themselves.
“Hebb said that our sensations, actions, and memories always involve a “cell assembly” — the pathway that extends from one brain center to another to another. Hebb argues that learning builds those pathways, and then repeated use deepens them, just like the canals down which boats travel. Luria went even further, explaining that every practical activity we perform requires us to use three different sets of pathways, or what Luria called functional systems.”
Under this model of brain function it is believed possible to rebuild, or retrain, these pathways and to restore functional ability even when a specific region of the brain has been injured or destroyed. This is good news as it implies that my rehabilitation efforts have the potential for a positive outcome. This accords with my experience. I continue to be frustrated by the fact that recovery appears to be glacially slow.
With respect to my injury, I think it likely that it was the pathways that became disrupted rather than damage being sustained by any specific area of the brain. In the accident of March 06th there was no blow to the head. My injury is the result of extremely rapid acceleration and high rotational torque. In essence, my injury represents an adult variation of “shaken baby syndrome.”
The HBW paper then goes on to discuss different brain centres and how they work. This sheds further light on my own injures. The brain centres are reviewed in the next post.