Could linguistic analysis predict who will get Alzheimer’s disease?
What scope is there for linguists to assist in establishing the likelihood of someone developing Alzheimer’s later in life? What would we look for? How could patterns of language be appropriately and reliably measured? If we found indicative patterns, what would we interpret them to signify? What would the ethical issues be of categorising people as at higher or lower risk of Alzheimer’s many years before symptoms appeared?
We know quite a lot about the changes in language that occur in different types of dementia, including Alzheimer’s. We know that some words are harder to retrieve than others – for example, one study found that natural objects were harder to name than manufactured ones; another found that verbs of cognition were more difficult to understand than verbs of motion. Research also found that people who later developed Alzheimer’s already had certain patterns in their language in early adulthood that were different from those of people who didn’t develop it. What does all this mean? What insights can linguistic theory give us about what exactly is being affected, when, and why?
There are many tantalising observations, but in fact, we don’t always even know whether a linguistic pattern is part of the problem or part of the solution. Take formulaic language, for instance. Should we construe the use of vague fillers like ‘something’ and ‘those people’ as indicative of not knowing more information about the referents, or as an attempt to rescue a potential gap in the output arising from naming difficulties? When is the repetition of questions and statements a sign of having forgotten what was said previously, and when is it a success, in enabling the person to say something, when novel output is difficult to generate?
In this talk, we will get up close to some of the measures that are used in capturing patterns in Alzheimer’s talk, and examine them with a linguist’s eye. A primary focus will be two current studies that I am conducting with colleagues, to profile of the language of people at greater or lesser genetic risk of future Alzheimer’s. I’ll reflect on the potential social risks of over-interpreting observations, and consider what linguistic patterns might really tell us about variation in the population.