Skip to main content

Research Repository

Advanced Search

Perirhinal cortex and the recognition of relative familiarity

Ameen-Ali, Kamar E.; Sivakumaran, Magali H.; Eacott, Madeline J.; O'Connor, Akira R.; Ainge, James A.; Easton, Alexander

Perirhinal cortex and the recognition of relative familiarity Thumbnail


Kamar E. Ameen-Ali

Magali H. Sivakumaran

Madeline J. Eacott

Akira R. O'Connor

James A. Ainge


Spontaneous object recognition (SOR) is a widely used task of recognition memory in rodents which relies on their propensity to explore novel (or relatively novel) objects. Network models typically define perirhinal cortex as a region required for recognition of previously seen objects largely based on findings that lesions or inactivations of this area produce SOR deficits. However, relatively little is understood about the relationship between the activity of cells in the perirhinal cortex that signal novelty and familiarity and the behavioural responses of animals in the SOR task. Previous studies have used objects that are either highly familiar or absolutely novel, but everyday memory is for objects that sit on a spectrum of familiarity which includes objects that have been seen only a few times, or objects that are similar to objects which have been previously experienced. We present two studies that explore cellular activity (through c-fos imaging) within perirhinal cortex of rats performing SOR where the familiarity of objects has been manipulated. Despite robust recognition memory performance, we show no significant changes in perirhinal activity related to the level of familiarity of the objects. Reasons for this lack of familiarity-related modulation in perirhinal cortex activity are discussed. The current findings support emerging evidence that perirhinal responses to novelty are complex and that task demands are critical to the involvement of perirhinal cortex in the control of object recognition memory.


Ameen-Ali, K. E., Sivakumaran, M. H., Eacott, M. J., O'Connor, A. R., Ainge, J. A., & Easton, A. (2021). Perirhinal cortex and the recognition of relative familiarity. Neurobiology of Learning and Memory, 182, Article 107439.

Journal Article Type Article
Acceptance Date Apr 9, 2021
Online Publication Date Apr 14, 2021
Publication Date 2021-07
Deposit Date Apr 12, 2021
Publicly Available Date May 20, 2021
Journal Neurobiology of Learning and Memory
Print ISSN 1074-7427
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 182
Article Number 107439


You might also like

Downloadable Citations