The importance of the comparative approach to studying the brain cannot be overstated. The comparative approach allows us to compare human brains to brains of non-humans.
One of the key findings in this area is that the difference between human brains and brains of other species are often quantitative rather than qualitative. Comparative studies do reveal differences, but they also reveal many similarities that can lead to a better understanding of evolution and brain development. The primary benefits of using the comparative approach are that simpler brains found in other species make it more likely that brain-behavior relationships will be revealed, and there are fewer ethical restrictions applied to the study of other species.
Researchers who work with our closest relatives, chimps, assume that the things learned about chimps’ brains and behavior could be applied to understanding human brains and behavior. Researchers can also make meaningful comparisons with more distantly related species: slugs, fruit flies, rats and cats. Brain-behavior comparisons across species provide information that is difficult to obtain from studying a single species.
It is important to keep in mind the differences between species are as important as the similarities. Identifying similarities and differences give us a better understanding of the structure and function of the brain.
Here are some examples of how the comparative approach can be applied:
- Rat behavior is complex, and most structures of the rate brain are similar to those of the human brain. The cortical function of lab rats is very similar to that of humans.
- Slugs provide important information on how neurons interconnect to produce behavior. The slug’s nervous system is relatively simple making it easier to the study than humans.
- Fruit flies provide useful information concerning the genetic basis of behavior because many generations of fruit flies with genetic alterations can be bred rapidly in the lab.
The comparative approach is used for three primary lines of research: understanding basic brain mechanisms, designing animal models of human neurological disorders and describing the evolutionary development of the brain.
Researchers produce neurological disorders in animals, manipulate variables in an effort to understand the cause of the disorders and then design treatments to combat the disorder. Parkinson models have been developed in rats, mice and monkeys. Studying rats that had a disease similar to Parkinson’s developed the drug L-dopa.
In conclusion, using the comparative approach has led to important discoveries in area of basic brain function, disease treatments, and knowledge concerning the evolutionary development of the brain.
Nerve cell photo available from Shutterstock