The field of “gerolinguistics” is becoming more and more important. The word was first coined by G. Cohen in 1979 and it has been regularly used ever since.
How do older people read ? How do they perform when trying to understand difficult sentences ? It was the idea I was following when I recently decided to read a few papers about linguistic abilities and aging. As I work on different reader profiles I thought it would be an interesting starting point.
The fact is that I did not find what I was looking for, but was not disappointed since the assumption I had made on this matter were proved wrong by recent research. Here is what I learned.
Interindividual variability increases with age
First of all, it is difficult to build a specific profile that would address ‘older people’, as this is a vast category which is merely a subclass of the ‘readers’, and which (as them) contains lots of variable individual evolutions. Very old people (and not necesarily old people) do have more difficulties to read, but this can be caused by very different factors. Most of all, age is not a useful predictor :
“Many aspects of language comprehension remain markedly intact among older adults, at least at the single-word level.” (Abrams & Farrell 2011)
Not only does dementia set on quite late, the existence of several diseases like Alzheimer or Parkinson adds to the variety of the cases :
“Given the many extraneous influences that can moderate the cognitive aging process, it is not surprising that interindividual variability increases with age.” (Drag & Bieliauskas 2010)
According to what I read, if no particular signs of illness are detected, reading comprehension abilities as a whole only decline at the age of 75 or more. An interesting fact is that middle-aged till old people have a larger vocabulary :
“Vocabulary has been shown to increase throughout the middle adult years but to decline in late adulthood.” (Kemper et al. 2001)
Retrieval of vocabulary and working memory
Older people are bound to better recognize predictable series of words, they have a deeper understanding of language which they use to make up for the effects of sensory weaknesses.
“Sensory inefficiency means that more cognitive resources and effort need to be put toward stimulus identification, taking these resources away from more complex, cognitive operations such as memory for the stimuli.” (Drag & Bieliauskas 2010)
That means the study of word series and especially collocations is relevant at this point, since older people experience more difficulties when they are confronted with linguistic ‘novelties’ such as unexpected collocations :
“An age-related increase in vocabulary (a crystallized ability) and a lifetime of reading experience (growth of particularized knowledge and proceduralized skill) can minimize deleterious effects of aging in word-level processing. On the other hand, older adults may be more disrupted in word decoding by sensory challenges and when meaning instantiation is resource-consuming (e.g., in the case of lexical novelty and the activation of inappropriate meanings that must be inhibited).” (Stine-Morrow et al. 2006)
Here come several theories on how working memory evolutions affect text comprehension, as working memory is a leading research topic in the field of psycholinguistics. It is not clear whether there is at all a correlation, as not all scientists agree on this point. Here is a tempered conclusion on memory decline :
“Aging does not lead to a global memory decline but rather has differential affects on specific aspects of memory.” (Drag & Bieliauskas 2010)
The influence of elaborate text
Another proof for the fact that readability formulas are often not reliable is that elaborated text (and as such longer text) seems to be better understood by older people :
“While elaboration in text adds complexity, it also provides contextual support for the encoding of individual ideas.”
“Older adults derive benefit not only from greater elaborative content but also a relatively homogeneous and incremental amount of elaboration that minimises frequent switches between distinct levels of text processing.” (Shake et al. 2009)
This is an interesting idea which is for instance addressed by the Coh-Metrix project : coherence is a feature which makes texts easier to read, and not simply longer.
Elderspeak
The speech register named elderspeak (referring to the way older people are addressed) is interesting, since it seems to be a failed attempt at being more understandable. Studies show it is not necessary to use fewer clauses and shorter utterances for instance, as older people themselves not only can benefit from more cohesive texts but also produce themselves sentences which are often richer as those of younger adults :
“To some extent, use of elderspeak is driven by stereotypical expectations rather than by the actual characteristics of conversational partners.” (Thornton & Light 2006)
That means elderspeak is possibly inappropriate, if it does not make texts or sentences less understandable it does not take advantage of an existing comprehensibility range either. These examples show how variable the notion of comprehensibility really is.
Sources
The review by Drag & Bieliauskas (2010) is often quoted in this post as it offers what seems to be a convincing state of the art.
- L. Abrams and M. T. Farrell, Language Processing in Normal Aging, Routledge, 2011, pp. 49-73.
- L. L. Drag and L. A. Bieliauskas, “Contemporary review 2009: cognitive aging”, in Journal of geriatric psychiatry and neurology, vol. 23, iss. 2, pp. 75-93, 2010.
- M. C. Shake, S. R. Noh, and E. A. L. Stine-Morrow, “Age Differences in Learning from Text: Evidence for Functionally Distinct Text Processing Systems”, in Applied Cognitive Psychology, vol. 23, iss. 4, pp. 561-578, 2009.
- R. Thornton and L. L. Light, “Language comprehension and production in normal aging”, in Handbook of the Psychology of Aging, Birren, J.E. and Schaie, W.K.(eds.), Amsterdam: Elsevier, 2006, pp. 261-287.
- E. A. L. Stine-Morrow, L. M. S. Miller, and C. Hertzog, “Aging and Self-Regulated Language Processing”, in Psychological Bulletin, vol. 132, iss. 4, pp. 582-606, 2006.
- S. Kemper, M. Thompson, and J. Marquis, “Longitudinal change in language production: Effects of aging and dementia on grammatical complexity and propositional content”, in Psychology and Aging, vol. 16, iss. 4, pp. 600-614, 2001.
- G. Cohen, “Language comprehension in old age”, in Cognitive Psychology, vol. 11, pp. 412-429, 1979.