A New Measure of Mnemonic Discrimination Applicable to Recognition Memory Tests with Continuous Variation in Novel Stimulus Interference
dc.contributor.author | Leger, Simon | |
dc.contributor.copyright-release | Not Applicable | en_US |
dc.contributor.degree | Master of Science | en_US |
dc.contributor.department | Department of Psychiatry | en_US |
dc.contributor.ethics-approval | Not Applicable | en_US |
dc.contributor.external-examiner | Heather Neyedli | en_US |
dc.contributor.manuscripts | Not Applicable | en_US |
dc.contributor.thesis-reader | Thomas Trappenberg | en_US |
dc.contributor.thesis-reader | Martin Alda | en_US |
dc.contributor.thesis-reader | Aaron Newman | en_US |
dc.contributor.thesis-supervisor | Abraham Nunes | en_US |
dc.date.accessioned | 2024-08-14T16:27:51Z | |
dc.date.available | 2024-08-14T16:27:51Z | |
dc.date.defence | 2024-07-31 | |
dc.date.issued | 2024-08-12 | |
dc.description.abstract | Background: Mnemonic discrimination (MD) involves distinguishing new stimuli from memories of highly similar “lure” items or events, and is a putative indirect probe of dentate gyrus functioning. MD is impaired in the elderly and in individuals with hippocampal lesions, schizophrenia, major depressive disorder, and Alzheimer’s disease. The gold-standard MD test, called the mnemonic similarity task (MST), is rarely used in clinical research. We thus aimed to demonstrate convergent validity between the MST’s MD measure and a novel analysis method that extracts informa- tion about MD that could be used in widely clinically used recognition memory tests that do not have categorical distinctions between “lures” and “foils.” Methods: By fitting a logistic function to the relationship between stimulus inter- ference and the probability of classifying a stimulus as novel, at the single participant level, we derived participant-level indices of MD (λ) and overall recognition memory performance (∆). We applied the novel measures to MST data from two indepen- dent datasets (N=18; N=67), and to synthetic MST data. Using linear mixed-effects modelling, we sought to confirm that λ predicts the MST’s lure discrimination index (LDI), while ∆ predicts the MST’s overall recognition memory index (REC). Results: Across all datasets, λ predicted LDI (β=0.76, 95% CI [0.62-0.91], p<0.001), but not REC (β=0.06, 95% CI [-0.03-0.15], p=0197), while ∆ predicted REC (β=0.93, 95% CI [0.83-1.02], p<0.001), but not LDI (β=-0.06, 95% CI [-0.20-0.09], p=0.438). The λ and ∆ indices were not correlated. Simulations suggest that λ may be more robustly estimated in participants with stronger overall recognition performance. Conclusion: Our novel measure accurately indexes MD, without correlating with overall recognition memory performance. Future studies should apply it to large clinical datasets with widely used recognition memory tests. | en_US |
dc.identifier.uri | http://hdl.handle.net/10222/84407 | |
dc.language.iso | en | en_US |
dc.subject | Recognition Memory | en_US |
dc.subject | Mnemonic Discrimination | en_US |
dc.subject | Mnemonic Similarity Task | en_US |
dc.subject | MST | en_US |
dc.title | A New Measure of Mnemonic Discrimination Applicable to Recognition Memory Tests with Continuous Variation in Novel Stimulus Interference | en_US |