Recognition memory and the medial temporal lobe: a new perspective

Abstract

Recognition memory is widely viewed as consisting of two components, recollection and familiarity, which have been proposed to be dependent on the hippocampus and the adjacent perirhinal cortex, respectively. Here, we propose an alternative perspective: we suggest that the methods traditionally used to separate recollection from familiarity instead separate strong memories from weak memories. A review of work with humans, monkeys and rodents finds evidence for familiarity signals (as well as recollection signals) in the hippocampus and recollection signals (as well as familiarity signals) in the perirhinal cortex. We also indicate ways in which the functions of the medial temporal lobe structures are different, and suggest that these structures work together in a cooperative and complementary way.Declarative memory refers to the capacity to consciously remember the past and depends on the integrity of the medial temporal lobe (comprising the hippocampus, the dentate gyrus and the subicular complex, together with the entorhinal, perirhinal and parahippocampal cortices, which lie along the adjacent parahippocampal gyrus). One of the most widely studied examples of declarative memory is recognition -the ability to judge a recently encountered item as having been presented previously. Recognition memory is widely viewed as consisting of two components: recollection and familiarity 1,2 . Recollection involves remembering specific contextual details about a prior learning episode; familiarity involves simply knowing that an item was presented, without having available any additional information about the learning episode.Interest in this distinction greatly increased when Brown and Aggleton 3 proposed a neuroanatomical basis for these two processes. Their proposal was that recollection depends on the hippocampus, whereas familiarity depends on the adjacent perirhinal cortex. Since that time, others have elaborated on this idea 4-6 , and it has become the basis for the design and analysis of a good deal of experimental work. However, alternative formulations have also been advanced about the nature of recognition memory and its anatomical foundations 7,8 , and a consensus has not yet emerged.Correspondence to L.R.S. e-mail: lsquire@ucsd.edu. NIH Public Access Author ManuscriptNat Rev Neurosci. Author manuscript; available in PMC 2008 April 21. Published in final edited form as:Nat Rev Neurosci. 2007 November ; 8(11): 872-883. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptHere, we review studies of humans, monkeys and rodents that have investigated the functional organization of the medial temporal lobe using a variety of methods: lesions, single-unit activity and neuroimaging. The general organizational principles of the medial temporal lobe are similar in these species 9 , and it is reasonable to suppose that what is learned about medial temporal lobe function in one species has relevance to the others. Although many of the studies have been interpreted as providing support for the n...

Unraveling the contributions of the diencephalon to recognition memory: A review

“…Consequently, any account of diencephalic mechanisms supporting recognition memory must be able to explain this asymmetric relationship. As already explained, this dissociation poses problems for single-process models of recognition memory (Squire et al 2007). 5.…”

“…This arrangement ensures that medial temporal structures such as the perirhinal cortex and hippocampus are ideally placed to detect rapidly the repeat occurrence of an event and then initiate appropriate brain responses (Brown and Aggleton 2001;Diana et al 2007;Eichenbaum et al 2007;Squire et al 2007). Once the medial temporal lobe has performed this function, why should additional, diencephalic nuclei be required for the same cognitive task?…”

“…An alternative model assumes that recognition and recall draw on the same information and that the differences between recollection and familiarity lie in the strength of the trace (e.g., Squire et al 2007). Weak traces give rise to a feeling of knowing (familiarity).…”

Recognition memory: opposite effects of hippocampal damage on recollection and familiarity

“…A similar controversy exists over the findings from functional imaging studies. Different studies have shown either recollection-specific activation of the hippocampus 8 or activation that occurs more generally in medial temporal lobe areas associated with the strength of memory 9 .…”

Glucose modulates event-related potential components of recollection and familiarity in healthy adolescents

“…In this context, recollection can be defined as memory for an event with retrieval of accompanying spatiotemporal contextual details, whereas familiarity does not involve this degree of episodic richness (Tulving 1985;Aggleton and Brown 2006). It has been proposed that recollection is mediated by the hippocampus; by contrast, familiarity is thought to be subserved by the perirhinal cortex (Brown and Aggleton 2001;Aggleton and Brown 2006;Eichenbaum et al 2007; but see Squire et al 2007 for a conflicting view). The basis of this neuroanatomical distinction is largely predicated upon a series of hippocampal amnesic cases in which familiarity processes are relatively spared in the context of recollection deficits (e.g.…”