Research shows intrusions in memory tests can predict cognitive impairment in abnormal aging. However, there still is a need for additional research regarding the association of intrusions in verbal fluency tasks and clinical diagnosis of mild cognitive impairment, and dementia. The aim of this research is to determine if there is an association between intrusion totals in verbal fluency tasks and diagnosis, longitudinally (across 3 years), if there are significant differences between category and phonemic fluency tasks in intrusion total scores, and if progression from cognitively normal (CN) to mild cognitive impairment (MCI) or dementia and from MCI to dementia can be indicated through differences in intrusion scores.

Participants were recruited from the Memory Disorders Center at Wien Center for Alzheimer’s Disease and Memory Disorders at Mount Sinai Medical Center in Miami, Florida to take part in the ongoing 1Florida Alzheimer’s Disease Research Center (ADRC) project. At baseline, participants had an average of 15 years of education (M = 15.00, SD = 3.65), were an average of 72.24 years old (M = 72.24, SD = 7.99), and were 62.93% female. At baseline (Visit/ year 1), there were 88 CN, 229 MCI, and 58 dementia participants. Participants were asked to complete Categorical and Phonemic verbal fluency tasks in which correct words said and intrusions were collected. Intrusion totals were quantified as the sum of intrusions within each subsection of the tasks (i.e., fruits, vegetables, and animals for the category; F, L, A, S for phonemic). Intrusion totals and correct words were analyzed across diagnostic groups and progressor vs. non-progressor groups.

Results indicated that intrusions are significantly associated with diagnosis in Phonemic fluency tasks, however, this was not the case for Category fluency tasks. Higher phonemic fluency task intrusions were associated with more severe cognitive decline. In progressor versus non-progressor groups there were no significant differences in intrusion totals. Lower correct scores for category and phonemic fluency tasks were found to be significantly associated with increased severity of diagnosis. Lower correct scores also significantly predicted progressor classification.

These findings suggest possible association of higher intrusion errors in verbal fluency tasks with more severe cognitive decline. Although these indications were significant, further research exploring intrusions and cognitive diagnosis are still needed.