Checking the sources: The Split Brain Studies Part 2

A few months ago, I began reviewing some of the sources listed on the VARK bibliography. I was curious just what some of these well known and highly reputable sources had to do with VARK theory. Thus far, my conclusions have been disappointing. Four of my recent posts centered around Alan Baddeley’s memory book (Your Memory: A User’s Guide) and found nothing substantial to support VARK theory (those posts can be read through each of these links: sensory memory, visual imagery, semantic memory, workingmemory). In the post before that one, I reviewed Roger Sperry’s review of split brain work and found no relevant evidence to support VARK theories (which can be read here). So, here I go again. This time I am looking for the relevance of their Gazzaniga(1973) citation. As with the Sperry citation, it is cited internally in one of the early VARK papers (Fleming and Mills, 1992). Here is the quote:

“By questioning students, we found that many students attributed their learning difficulties to the form in which course material was presented. Some students found they had difficulties learning in situations where the course material was only presented orally, while others reported similar difficulties when the material was primarily in written form. Still other students experienced difficulty with ideas that were presented in graphics or 'without any associated concrete experiences.’ These insights prompted us to focus on sensory modality as a learning style dimension that had some preeminence over others. The notion that the way information is initially taken in by a learner influences what subsequently occurs has intuitive appeal.

“We found support for this notion in literature on neuro-linguistic programming (NLP) (Handler, 1976, 1979; McLeod, 1990; Stirling, 1987) that discussed the different perceptual modalities (aural, visual, and kinesthetic). The following questions were suggested from our exploration of this field of study, split-brain research (Gazzaniga, 1973; Sperry, 1973; Springer & Deutsch, 1985) and left brain/right brain modalities (Buzan, 1991; Edwards,1979):

1. How can students be encouraged to reflect on the nature, extent and implications of their sensory modalities?

2. As a consequence of exploring their sensory modality preference, will students modify their existing learning strategies in ways that assist their learning?”

How these questions arise from the split brain research remains to be seen. My review of Sperry’s work shed no light on that one. Perhaps the answer lies in the Gazzaniga source?

Unfortunately, I could find NOTHING in the Gazzaniga source that was worth discussing in relation to VARK. I do find these studies fascinating though, so I will share with you a few of the more interesting quotes and findings from this article. There is not much to do with VARK here, but I think it is fun nonetheless…

As Sperry’s paper was a review of mostly animal studies of split brain, Gazzaniga’s paper is a review of mostly human neuropsych work. As I discussed in the Sperry post, the prevailing theory in split brain research concerns the lateralization of language. Language and/or speech seem to be a left hemisphere task, with the contributions and abilities of the right hemisphere focusing on the spatial aspects of life (See below).

From Gazzaniga (1973)- Notice the superiority of the left hand (right hemisphere) at drawing (a spatial task).

In his paper, Gazzaniga describes a very interesting issue that researchers have to deal with when examining the linguistic abilities of the right hemisphere. Apparently, researchers have to look out for “cross-cuing” from one hemisphere to the other.

“We had such cross-cuing during a series of tests of whether the right hemisphere could respond verbally to simple red or green stimuli. At first, after either a red of a green light was flashed to the right hemisphere, the patient would guess the color at a chance level, as might be expected if the speech mechanism is solely represented in the left hemisphere. After a few trials, however, the score improved whenever the examiner allowed a second guess.

“We soon caught on to the strategy the patient used. If a red light was flashed and the patient by chance guessed red, he would stick with that answer. If the flashed light was red and the patient by chance guessed green, he would frown, shake his head and then say, “Oh no, I meant red.” What was happening was that the right hemisphere saw the red light and heard the left hemisphere make the guess “green.” Knowing that the answer was wrong, the right hemisphere precipitated a frown and a shake of the head, which in turn cued in the left hemisphere to the fact that the answer was wrong and that it had better correct itself! We have learned that this cross-cuing mechanism can become extremely refined. The realization that the neurological patient has various strategies at his command emphasizes how difficult it is to obtain a clear neurological description of a human being with brain damage.”

What does this have to do with VARK? Nothing at all. Fleming and Mills (1992) cites Gazzaniga (1973) and Sperry (1973) to validate their theory, but it is not clear how in fact these papers do that. How does the idea of the lateralization of language to the left hemisphere or the lateralization of spatial abilities to the right hemisphere lead to individual differences between learning styles that are sensory modality based (ie. a visual learner, auditory learner, read/writing learner, or kinesthetic learner)? Unless you are a split brained patient, the fact that these abilities (language and spatial) are separated across the hemispheres does not affect you. We are all able to process language and spatial tasks. Within us “normal” (that is, non split-brained) people, we can take items that are presented spatially and describe them linguistically (describe a picture), and we are able to take something linguistic and represent it spatially (drawing a picture to represent a written story). These studies are fascinating and I love reading them, but I fail to see how they either support or refute VARK theory.

References

Fleming, N.D. & Mills, C. (1992). Not Another Inventory, Rather a Catalyst for Reflection. To Improve the Academy, 11, 137-155.

Gazzaniga, M. C. (1973). The split brain in man. In R. E. Ornstein (Ed.), The nature of human consciousness: A book of readings (pp. 87-100). San Francisco: W. H. Freeman

Sperry, R. (1973). Lateral specialization of cerebral function in the surgically separated hemisphere. In F. J. McGulgan, & R. A. Schoonover, (Eds.), The psychophysiology of thinking (pp. 209-229). New York. Academic Press.