Propositional idea density in older men’s written language: Findings from the HIMS study using computerised analysis

Abstract

Decline in linguistic function has been associated with decline in cognitive function in previous research. This research investigated the informativeness of written language samples of Australian men from the Health in Men’s Study (HIMS) aged from 76 to 93 years using the Computerised Propositional Idea Density Rater (CPIDR 5.1). In total, 60 255 words in 1147 comments were analysed using a linear-mixed model for statistical analysis. Results indicated no relationship with education level (p = 0.79). Participants for whom English was not their first learnt language showed Propositional Idea Density (PD) scores slightly lower (0.018 per 1 word). Mean PD per 1 word for those for whom English was their first language for comments below 60 words was 0.494 and above 60 words 0.526. Text length was found to have an effect (p = <0.0001). The mean PD was higher than previously reported for men and lower than previously reported for a similar cohort for Australian women.

• Ageing
• corpus linguistics
• idea density
• language decline
• propositional density

Acknowledgements

The authors gratefully acknowledge the Health in Men Study Investigators, Professors Paul Norman, Bu Yeap, Osvaldo Almeida and Jonathan Golledge. We also wish to thank Megan Vile who transcribed the original comments.

Declaration of interest

The authors report no conflicts of interest. The research on which this article is based was conducted as part of the Health in Men’s Study, the Western Australian Centre for Healthy Ageing (WACHA), University of Western Australia.

Notes

¹The convention of reporting PD scores per 10 words has traditionally been used, however, CPIDR uses the format of reporting PD per word. For ease of comparison with previous studies, we have chosen to report in both formats, PD per word and PD per 10 words.