Interactive Brain Map / The “Swiss Army Knife Model”
Here’s a useful reference for any reader. Dr. Robert P. Lehr provides a concise and straight-forward list of brain areas and their functions. An interactive brain map follows the article, along with a diagram of the brain for further exploration.
Psychologists describe the animal brain as modular; that is, specific areas/systems are responsible for specific functions. For example, the occipital lobe of the brain is responsible for vision, the limbic system for emotion, and the motor cortex for muscle movement. Some psychologists have referred to this modularity as a “Swiss Army Knife model.” Like each tool in the knife, brain modules are somewhat independent; however, these modules, or tools, interact to create a larger entity.
In traumatic brain injury (TBI) cases, certain modules may be affected, while others remain completely normal. An injury to the frontal lobe may greatly affect an individual’s planning and problem solving (and thus greatly affecting that individual’s pre-injury routine), but may have no effect on the individual’s vision. Conversely, brain damage in the Occipital lobe may render an individual blind, but have little effect on frontal lobe functioning.
An oft-cited case is that of railroad worker Phineas Gage. While helping to the build a railroad in 1848, Gage’s head was severely struck by a three-foot iron (traveling so fast that it went in one side and out the other!). The iron struck mostly Gage’s frontal lobe. As his physical recovery continued to improve post-accident, Gage’s personality seemed to have drastically changed. The fact that a three-foot rod could so greatly affect personality but not affect functions such as sight and speech helped solidify the notion of a modular brain.
For another interesting case, see patient HM. In 1953, HM’s hippocampus was removed in an experimental surgery for his epilepsy; as a result, HM lost the ability to form new memories, but retained the ability to recall long-term memories. This has led psychologists to believe long-term and short-term memories operate on separate (albeit sometimes intertwined) pathways.
The Swiss Army Model is a useful way of understanding brain functions. However, one must always keep in mind the complexity of the human brain and its networking. Not only does current research continue to illuminate modules and specific pathways, but more and more we are discovering how hard it is to separate one module from another.
As Dr. Lehr concludes, problem areas in TBI rehabilitation often affect each other (networked modules). In his example, re-establishing balance and eliminating dizziness may help to improve concentration and attention, in turn improving planning and problem solving. In many cases such as this one, it becomes impossible to separate the individual tools of the Swiss Army Knife.
