Ageing makes us dyslexic

Abstract

Background: The effects of typical ageing on spoken language are well known: word production is disproportionately affected while syntactic processing is relatively well preserved. Little is known however about how ageing affects reading. Aims: What effect does ageing have on written language processing? In particular, how does it affect our ability to read words? How does it affect phonological awareness (our ability to manipulate the sounds of our language)? Methods & Procedures: We tested 14 people with Parkinson's disease (PD), 14 typically ageing adults (TAA), and 14 healthy younger adults on a range of background neuropsychological tests and tests of phonological awareness. We then carried out an oral naming experiment where we manipulated consistency, and a nonword repetition task where we manipulated the word-likeness of the nonwords. Outcomes & Results: We find that normal ageing causes individuals to become mildly phonologically dyslexic in that people have difficulty pronouncing nonwords. People with Parkinson's disease perform particularly poorly on language tasks involving oral naming and metalinguistic processing. We also find that ageing causes difficulty in repeating nonwords. We show that these problems are associated with a more general difficulty in processing phonological information, supporting the idea that language difficulties, including poorer reading in older age, can result from a general phonological deficit. Conclusions: We suggest that neurally this age-induced dyslexia is associated with frontal deterioration (and perhaps other regions) and cognitively to the loss of those executive processes Running head: Ageing MAKES US DYSLEXIC 2 that enable us to manipulate spoken and written language. We discuss implications for therapy and treatment.

How to get by with half a loop – An investigation of visual and auditory codes in a case of impaired phonological short-term memory (pSTM)

“…a Control data from 21 young adult participants, taken from Nickels and Cole-Virtue (2004). b Control data from 20 typically ageing adults, taken from Harley et al (2013). The original paper does not split data into conditions.…”

“…The participant simply has to indicate whether the pair rhymes or not. Harley, Oliver, Jessiman and MacAndrew (2013) administered these tests with a group of 20 typically ageing older adults and reported that mean accuracy for the written version was 54.20 out of 60 (SD ¼ 2.63), while the mean for the auditory version was 55.65 (SD ¼ 2.48). We used these data as a normative estimate for comparison with CT, who also performed written and auditory versions of the rhyme judgement task.…”