We're all familiar with false popular memes that spread faster than they can be stomped out: You only use 10% of your brain. Al Gore said he invented the internet. Perhaps it doesn't surprise you that some memes in popular culture can't be killed. But does the same thing happen in science?
Most of you have probably heard of Broca's aphasia and Wernicke's aphasia. Every textbook and every college course on language and the brain describes the connection between damage to these areas, and the speech deficits named after them.
Also, both are probably wrong. Both areas were mistakenly associated with their aphasias because they are near or surrounded by other areas which, when damaged, cause the aphasias. Yet our schools continue teaching the traditional, erroneous story; including a lecture in 9.14 at MIT given in 2005. Both the Wikipedia entry on Wernicke's aphasia and the Wikipedia entry on Broca's aphasia are still in error; the Wikipedia entry on Wernicke's area has got it straight.
Is it because this information is considered unimportant? Hardly; it's probably the only functional association you will find in every course and every book on the brain.
Is it because the information is too new to have penetrated the field? No; see the dates on the references below.
In spite of this failure in education, are the experts thoroughly familiar with this information? Possibly not; this 2006 paper on Broca's area by a renowned expert does not mention it. (In its defense, it references many other studies in which damage to Broca's area is associated with language deficits.)
So:
- Am I wrong, and the evidence still implicates Broca's area and Wernicke's area in their aphasias above other areas?
- If I'm right, why can't the new understanding displace the old understanding?
- Is this a general failure in the way we do science? Can you think of other examples where an important discovery can't penetrate its field?
References
Bogen JE, Bogen GM (1976). Wernicke's region—Where is it? Ann. N. Y. Acad. Sci. 280: 834–43.
Dronkers, N. F., Shapiro, J. K., Redfern, B., & Knight, R. T. (1992). The role of Broca’s area in Broca’s aphasia.
Journal of Clinical and Experimental Neuropsychology, 14, 52–53.
Dronkers NF., Redfern B B., Knight R T. (2000). The neural architecture of language disorders. in Bizzi, Emilio; Gazzaniga, Michael S.. The New cognitive neurosciences (2nd ed.). Cambridge, Mass: MIT Press. pp. 949–58.
Dronkers et al. (2004). Lesion analysis of the brain areas involved in language comprehension. Cognition 92: 145-177.
Mohr, J. P. (1976). Broca’s area and Broca’s aphasia. In H. Whitaker, Studies in neurolinguistics, New York: Academic Press.
Yeah, it happens from time to time. Sometimes these mistakes cause errors in basic things to be taught. I think schools especially are quite slow on the uptake of new ideas -- they have syllabuses and courses and textbooks, and it's quite a lot of trouble to change them, so they usually only get updated every couple years at best.
For example, schools often teach that light is both a particle and a wave, or that it's sometimes a particle and sometimes a wave, or that it has 'particle-wave duality'. They do this because in order to explain that light is just a particle and not a wave at all, one has to take the multiple universe theory of physics seriously.
In philosophy, an example of an important discovery not penetrating the field would be Karl Popper's epistemology. In that case, it's probably because, although it's fairly straightforward, what Popper actually says is very counter-intuitive. Most people don't understand what he means when he talks about us not actually needing any justification for our theories, because it's built into our culture and our language that we need to justify our theories in order to believe them.
No doubt in any field, you will find people ahead of the pack whose ideas haven't been adopted yet. Often they will be good ideas, but not presented well enough to make people understand, remember or pass on the ideas (especially if they're new and counter-intuitive). So, it can take time for them to get off the ground.