Comparison of Word-Writing Performance according to the Degree of Cognitive Decline: Focused on Patients with Subjective Memory Complaint, Mild Cognitive Impairment, and Alzheimer’s Disease

Purpose: Writing deficits are one of the major indicators of cognitive decline. The purpose of this study was to investigate the word-writing performance according to the degree of cognitive decline. Methods: Eighty-seven participants [30 patients with subjective memory complaint (SMC), 30 patients with amnestic mild cognitive impairment (aMCI), and 27 patients with Alzheimer’s disease (AD)] performed tasks involving writing regular words, irregular (phoneme-grapheme non correspondent) words, and nonwords. Data were collected using a tablet personal computer and digital pen and were analyzed according to four categories: the number of the correct response, error types, graphemic writing time, and pause time. Results: There was no difference between the SMC group and the aMCI group regardless of the writing task types, whereas the AD group scored significantly lower compared with the aMCI group in the irregular word-writing task. Additionally, all three groups showed poor performance in the order of regular words, nonwords, and irregular words. The most frequent error types in all three groups were substitution, elision, and addition. There was no difference in the graphemic writing time and pause time. Conclusion: Our findings show that declined cognitive function may affect the lexical route during writing. This study is meaningful because it is the first attempt to investigate the word-writing performance according to the degree of the neuropathological deficits.