ABSTRACT
Leveraging recent advances in automated language analysis and anovel statistical approach utilizing an independent control group, we explored changes in lexical output across two published works of a man diagnosed with semantic dementia. We found significant increase in adverb usage and decline in familiarity, meaningfulness, age of acquisition and co-occurrence probability over 2 years. Collectively, these indices suggest that WR’s narrative structure became progressively simpler, lexically less sophisticated, and that words commonly associated together no longer appeared in close proximity. Our study illustrates how degeneration of the semantic knowledge base impacts the production, content, and quality of literary works.
Abbreviations
ACE-IIIAddenbrooke’s cognitive examination third edition
ATLAnterior temporal lobe
BNCBritish national corpus
CCVControl corpus variability
FTD-FRSFrontotemporal dementia functional rating scale
MRCMedical Research Council
RCFRay complex figure
ROIRegion of interest
st.devStandard deviation
SYDBATSydney Language Battery Test
TAACOTool for the automatic analysis of cohesion
TAALESTool for the automatic analysis of lexical sophistication
TMTTrail making test
Acknowledgments
The authors would like to thank WR for his participation in our research and sharing his original manuscripts for this project. The authors acknowledge the technical assistance of Jim Matthews of the Sydney Informatics Hub, a Core Research Facility of the University of Sydney. The authors would also like to thank Dr Cristian Leyton Moscoso for his comments on the manuscript.
Disclosure statement
The authors report no competing interests.
Notes
1. Under the Net (published in 1954), The Sea, The Sea (1978) and Jackson’s Dilemma (1995).
2. WR’s spouse advised that there were occasions when WR would ask for an alternate word, or suggestions on phrasing. However, these occurrences were not frequent, and while she was not keeping an event diary, she did not feel that the frequency of these occurrences were noticeably different between the two books. We propose that these occurrences are not outside the boundaries of the “normal” writing process.