If you believe in learning styles, personalities, and so forth, skip this entry. It just reports that another of those balloons has been popped. However, it you’re into understanding the fascinating nature of humans’ thinking, there are a couple of morsels here.
Unless you’ve been putting your thumbs in your ears and wiggling your fingers while loudly saying, “Yadda, yadda, yadda. I’m not listening to you. I can’t hear a word you’re saying,” you’ve probably heard some educator talking about left-bained or right-brained learners, schools as catering to left-brained learners, girls as better at left-brained tasks and therefore better in schools, and so forth. (Think I’m kidding? Try this example from the widely circulated magazine, Scholastic or check on the sales of Drawing on the Right Side of the Brain.)
Fortunately, some folks have called “bologna” on this already. See, for examples:
- Elizabeth Hampton’s essay, “http://www.societyforqualityeducation.org/newsletter/archives/left.pdf from the Society for Quality Education (and check the sidebar for a link to the society’s home page) and
- Friend or TE, Dan Willingham provided one of his usual direct-and-grounded take-downs of this idea for the Washington Post‘s “Answer Sheet” in 2010: Willingham: Left/right brain theory is bunk.
Well, if that’s not enough (and it should be), a group of neuroscientists at the University of Utah (abstract and source follows) studied images showing the neural connections in the brain hemispheres of over 1000 people ranging from seven to 29 years of age. Although they found that there were functionally separate areas in the brain (e.g., language regions or hubs), these connections consistently showed lateralization between the major “hubs,” not a general individual type. They said that their
…analyses suggest that an individual brain is not “left-brained” or “right-brained” as a global property, but that asymmetric lateralization is a property of individual nodes or local subnetworks, and that different aspects of the left-dominant network and right-dominant network may show relatively greater or lesser lateralization within an individual.
Before you get carried away with interpreting that statement, please read the article. It’s available for free!
Nielsen, J. A., Zielinski, B. A., Ferguson M. A., Lainhart J. E., & Anderson J. S. (2013) An evaluation of the left-brain vs. right-brain hypothesis with resting state functional connectivity magnetic resonance imaging. PLoS ONE 8(8): e71275. doi:10.1371/journal.pone.0071275
Lateralized brain regions subserve functions such as language and visuospatial processing. It has been conjectured that individuals may be left-brain dominant or right-brain dominant based on personality and cognitive style, but neuroimaging data has not provided clear evidence whether such phenotypic differences in the strength of left-dominant or right-dominant networks exist. We evaluated whether strongly lateralized connections covaried within the same individuals. Data were analyzed from publicly available resting state scans for 1011 individuals between the ages of 7 and 29. For each subject, functional lateralization was measured for each pair of 7266 regions covering the gray matter at 5-mm resolution as a difference in correlation before and after inverting images across the midsagittal plane. The difference in gray matter density between homotopic coordinates was used as a regressor to reduce the effect of structural asymmetries on functional lateralization. Nine left- and 11 right-lateralized hubs were identified as peaks in the degree map from the graph of significantly lateralized connections. The left-lateralized hubs included regions from the default mode network (medial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction) and language regions (e.g., Broca Area and Wernicke Area), whereas the right-lateralized hubs included regions from the attention control network (e.g., lateral intraparietal sulcus, anterior insula, area MT, and frontal eye fields). Left- and right-lateralized hubs formed two separable networks of mutually lateralized regions. Connections involving only left- or only right-lateralized hubs showed positive correlation across subjects, but only for connections sharing a node. Lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater “left-brained” or greater “right-brained” network strength across individuals. Small increases in lateralization with age were seen, but no differences in gender were observed.
So, can the bunk. Quit blaming kids’ outcomes on irrelevant factors and let’s get to thinking about what matters: The things we can do to alter the teaching environment to improve those outcomes. Let’s see, we could start with having more light in the classrooms. O.K., how about adjusting the temperature up or down one degree? What? You think it would be more important to change the teaching?
Well, I agree.