The discrimination ratio derived from Novel Object Recognition tasks as a measure of recognition memory sensitivity, not bias

Sivakumaran, M.H., Mackenzie, A.K. ORCID: 0000-0002-6818-2838, Callan, I.R., Ainge, J.A. and O’Connor, A.R., 2018. The discrimination ratio derived from Novel Object Recognition tasks as a measure of recognition memory sensitivity, not bias. Scientific Reports, 8 (1): 11579. ISSN 2045-2322

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Translational recognition memory research makes frequent use of the Novel Object Recognition (NOR) paradigm in which animals are simultaneously presented with one new and one old object. The preferential exploration of the new as compared to the old object produces a metric, the Discrimination Ratio (DR), assumed to represent recognition memory sensitivity. Human recognition memory studies typically assess performance using signal detection theory derived measures; sensitivity (d′) and bias (c). How DR relates to d′ and c and whether they measure the same underlying cognitive mechanism is, however, unknown. We investigated the correspondence between DR (eye-tracking-determined), d′ and c in a sample of 37 humans. We used dwell times during a visual paired comparison task (analogous to the NOR) to determine DR, and a separate single item recognition task to derive estimates of response sensitivity and bias. DR was found to be significantly positively correlated to sensitivity but not bias. Our findings confirm that DR corresponds to d′, the primary measure of recognition memory sensitivity in humans, and appears not to reflect bias. These findings are the first of their kind to suggest that animal researchers should be confident in interpreting the DR as an analogue of recognition memory sensitivity.

Item Type: Journal article
Publication Title: Scientific Reports
Creators: Sivakumaran, M.H., Mackenzie, A.K., Callan, I.R., Ainge, J.A. and O’Connor, A.R.
Publisher: Nature Publishing Group
Date: 1 August 2018
Volume: 8
Number: 1
ISSN: 2045-2322
30030Publisher Item Identifier
Rights: Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit
Divisions: Schools > School of Social Sciences
Record created by: Linda Sullivan
Date Added: 14 Aug 2018 11:24
Last Modified: 14 Aug 2018 11:24

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