What's Happening in the Brain
Writing is part of language expression, so that what happens with written expression parallels other aspects of language loss in dementia. This area has attracted a lot of attention. Many scientists are especially interested in written language because of what it can tell us about how Alzheimer's disease operates. In a remarkable study in 1996, David Snowdon and colleagues working with religious from the School Sisters of Notre Dame, in what is popularly known as the Nun Study, made a remarkable finding. The nuns, who were now mostly in their 80's, had each written brief autobiographies of themselves as novitiates, prior to taking their vows. To their surprise, the investigators found that, more than the level of education that these women had (it was one of the major sources of variation between the sisters, who otherwise were all white women who lived similar lifestyles and had similar diets) what they had written 60 years before they were studied seemed to be able to predict who would get dementia. The nuns whose novitiate letters showed good grammar, and a larger number of ideas per set of words ('idea density') had the lowest risk of developing Alzheimer's disease in their 80's. By contrast, the nuns whose grammar was not complex, and who expressed few ideas, were at a very high risk of developing Alzheimer's disease. These observations were very powerful and predicted with more than 90 percent accuracy who would develop Alzheimer's disease. Similarly, analyses of the last novel written by Irish Murdoch, who shortly after developed Alzheimer's disease, showed that the writing had become less complex, with a lower idea density, compared with earlier novels.
Apart from observations about predicting who develops Alzheimer's disease, there is an interest in how the writing itself changes with the disease. Apart from a decline in the complexity of sentence structure, and the ideas conveyed, researchers have noticed that there are errors in grammar, words with similar sounds or meanings are substituted for each other, and spelling errors (especially for less used words) become very common.
There are also other characteristic changes in neurological syndromes that can accompany the various dementias, such as a tendency to write smaller ('micrographia') or to write smaller progressively down a page.
Further reading for 'what is happening in the brain':
Werner P, Rosenblum S, Bar-On G, Heinik J, Korczyn A. Related Articles, Links
Handwriting process variables discriminating mild Alzheimer's disease and mild cognitive impairment . J Gerontol B Psychol Sci Soc Sci. 2006;61:P228-36.
Garrard P, Maloney LM, Hodges JR, Patterson K. The effects of very early Alzheimer's disease on the characteristics of writing by a renowned author. Brain. 2005 Feb;128(Pt 2):250-60.
Forbes KE, Shanks MF, Venneri A. Related Articles, Links The evolution of dysgraphia in Alzheimer's disease. Brain Res Bull. 2004;63:19-24.
Snowdon DA, Kemper SJ, Mortimer JA, Greiner LH, Wekstein DR, Markesbery WR.
Linguistic ability in early life and cognitive function and Alzheimer's disease in late life. Findings from the Nun Study. JAMA. 1996;275:528-32.