Detecting Dementia Using Lexical Analysis: Terry Pratchett's Discworld Tells a More Personal Story.

Area of Science:

• Neurology and Cognitive Science
• Computational Linguistics
• Literary Analysis

Background:

• Dementia significantly impacts language, with changes often appearing years before clinical diagnosis.
• Early detection of cognitive decline is crucial for timely intervention and management.
• Previous studies indicate linguistic alterations like reduced vocabulary diversity in dementia patients.

Purpose of the Study:

• To investigate linguistic analysis for detecting early signs of cognitive decline.
• To examine the writings of Sir Terry Pratchett, diagnosed with Posterior Cortical Atrophy (PCA), a form of dementia.
• To identify potential linguistic markers preceding a formal dementia diagnosis.

Main Methods:

• Analysis of 33 Discworld novels by Terry Pratchett.
• Comparison of linguistic features before and after a determined turning point.
• Utilized adjective type-token ratios (TTR) to identify the turning point and assess lexical diversity.

Main Results:

• A significant decrease in lexical diversity (TTR) for nouns and adjectives was observed in later works.
• Increased total word count accompanied by decreased lexical diversity, indicating a shift towards simpler language.
• The decline in adjective TTR occurred approximately ten years before Pratchett's PCA diagnosis.

Conclusions:

• Subtle linguistic changes, such as reduced lexical diversity, may precede dementia diagnosis by years.
• Linguistic analysis shows promise as a tool for the early detection of cognitive decline.
• Further research is needed to validate these findings in larger populations and explore dementia-specific linguistic markers.