Transient global amnesia and functional retrograde amnesia: contrasting examples of episodic memory loss

Kritchevsky, Mark; Zouzounis, Joyce A.; Squire, Larry R.

doi:10.1098/rstb.1997.0157

Cited by 40 publications

(7 citation statements)

References 63 publications

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“…Some studies with TGA patients yielded no graded autobiographical memory loss in the sense of Ribot, possibly because of the variability of methods and testing, the temporal dynamics of the recovery from TGA, and hence the time point of testing (32). Notably, similar to our results, earlier studies in TGA also observed a temporal gradient with regard to semantic memory compatible with the possibility that hippocampal lesions also gradually affect semantic memory (30)(31)(32)(33)(34). Using PET, patients with Alzheimer's disease show a temporally graded autobiographical amnesia reflected in a gradual disengagement of the hippocampus in the recall of autobiographical memories for remote memories (29).…”

Section: Discussionsupporting

confidence: 80%

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness

Bartsch¹,

Döhring²,

Rohr

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

245

159

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Autobiographical memories in our lives are critically dependent on temporal lobe structures. However, the contribution of CA1 neurons in the human hippocampus to the retrieval of episodic autobiographical memory remains elusive. In patients with a rare acute transient global amnesia, highly focal lesions confined to the CA1 field of the hippocampus can be detected on MRI. We studied the effect of these lesions on autobiographical memory using a detailed autobiographical interview including the remember/know procedure. In 14 of 16 patients, focal lesions in the CA1 sector of the hippocampal cornu ammonis were detected. Autobiographical memory was significantly affected over all time periods, including memory for remote periods. Impairment of episodic memory and autonoetic consciousness exhibited a strong temporal gradient extending 30 to 40 y into the past. These results highlight the distinct and critical role of human hippocampal CA1 neurons in autobiographical memory retrieval and for re-experiencing detailed episodic memories.A utobiographical memory is one of the multifaceted forms of human memory that constitutes a major source for selfidentity, self-continuity, and self-awareness of an individual's life. Episodic autobiographical recollection includes conscious awareness for specific episodic situations embedded in time and space, and the ability of mental reliving of episodes of a person's history along the subjective and mental time axis (1). Considering the phenomenological experience of remembering, episodic recollection involving re-experiencing requires autonoetic consciousness in contrast to semantic knowledge of memory, which is associated with noetic consciousness (2).It is generally accepted that the hippocampus plays a critical role in episodic memory, including autobiographical memory, as neuroimaging data show hippocampal activation in autobiographical memory retrieval tasks, supporting that the hippocampus is an integral structure of the autobiographical network (3, 4). The involvement of the hippocampus culminates in the question of the temporal contribution of the hippocampal-neocortical interaction in the consolidation and recollection of remote episodic memory (5). One view, according to the standard model of consolidation, considers the hippocampus as a temporary relay structure that facilitates the transition of newly encoded hippocampus-dependant memory traces to its permanent storage and consolidation in neocortical structures, resulting in hippocampus-independent remote memories (6). This transitory role of the hippocampus is thought to be reflected in the temporal gradient of retrograde amnesia seen in patients with lesions to the medial temporal lobe (MTL). Evidence for this time-limited role of the hippocampus has come from lesion studies of amnestic patients and neuroimaging studies (7,8). In contrast, the multiple trace theory (MTT) postulates a permanent contribution of the hippocampus in retrieving and recollection in terms of a binding module for episodic memories (9). This v...

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Section: Discussionsupporting

confidence: 80%

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness

Bartsch¹,

Döhring²,

Rohr

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

245

159

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“…R. Miller & Matzel, 2006;Riccio & Richardson, 1984;Spear, 1973 Brown, 2002;Squire & Alvarez, 1995). However, it is also common to observe that the 'forgotten' time period occurring prior to injury 'shrinks' with the passage of time (e.g., Russell & Nathan, 1946; also see Kritchevsky, Zouzounis, & Squire, 1997). This is similar to 'spontaneous recovery' e ects reported in extinction, counter-conditioning (Bouton, 2002), and pairedassociate learning studies (A.…”

Section: Recovery From Experimentally-induced Amnesiasupporting

confidence: 58%

Persistence and plasticity in the human memory system: An empirical investigation of the overwriting hypothesis

Hardwicke¹

2017

Preprint

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The human memory system must resolve a critical tension, ensuring that knowledge endures over time (persistence), whilst simultaneously retaining a capacity for updating when knowledge is outdated or erroneous (plasticity). In this thesis, I examine the provocative idea that memory traces can be overwritten with new information, especially during transient periods of retrieval-induced plasticity that occur when a trace undergoes reconsolidation. A systematic review of human reconsolidation studies finds that the evidentiary support for this claim is remarkably tenuous. Furthermore, the theory fails to survive several strong empirical tests. In Experiments 1-7, I do not replicate a previous finding that is widely cited as a convincing demonstration of human reconsolidation. In Experiments 8-10, I revisit the ‘destructive updating’ account of the classic ‘misinformation effect’ in the context of reconsolidation theory. These experiments show that the effect can be eliminated when an appropriate recognition test is used, demonstrating that event traces are not irrecoverably lost, and therefore cannot have been overwritten during reconsolidation. In Experiment 11, I examine whether prior retrieval will help or hinder the correction of naturally occurring semantic misconceptions. Contrary to reconsolidation theory, I find that knowledge updating is not contingent on memory retrieval, nor does it result in the overwriting of prior knowledge.Finally, in the context of media ‘breaking news’ reports (Experiment 12), I find that the provision of an explicit retraction message, coupled with an alternative account with high causal coverage, is insufficient to eliminate reliance on false information. Finally, I contend that the widespread proliferation of ad hoc hypotheses, and the absence of systematic direct replication, has caused the field of reconsolidation to descend into a theoretical quagmire.I make several recommendations based on the principles of open science that may help to restore mechanisms of self-correction and foster genuine theoretical progress.

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“…One of the 10 patients confessed to malingering his amnesia, and his test scores are presented here so that they can be compared to the scores of the other patients. Preliminary findings for these patients appeared in an earlier report, which compared functional amnesia with transient global amnesia (Kritchevsky et al 1997).…”

mentioning

confidence: 98%

Functional Amnesia: Clinical Description and Neuropsychological Profile of 10 Cases

Kritchevsky¹,

Chang²,

Squire³

2004

Learn. Mem.

Self Cite

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We carried out the first neuropsychological study of a series of patients with functional amnesia. We evaluated 10 patients, first with a neurological examination and then with three tests of anterograde amnesia and four tests of retrograde amnesia. Excluding one patient who later admitted to malingering, all patients had a significant premorbid psychiatric history and one or more possible precipitating factors for their amnesia. Eight of the 10 patients still had persistent retrograde amnesia at our last contact with them (median = 14 mo after the onset of amnesia). On tests of anterograde amnesia, the patients performed normally as a group, though some patients scored poorly on tests of verbal memory. On tests of retrograde amnesia, all patients had difficulty recollecting well-formed autobiographical memories of specific events from their past. In contrast, patients performed as well as controls at distinguishing the names of cities from fictitious city names. On remote memory tests for past public events and famous faces, different patients exhibited different but internally consistent patterns of impaired and spared performance. The variability in the clinical and neuropsychological findings among our patients may be understood by supposing that memory performance is poor in proportion to how directly a test appears to assess a patient's commonsense concept of memory. The presentation of patients with functional amnesia is as variable as humankind's concept of what memory is and how it works.

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Transient global amnesia and functional retrograde amnesia: contrasting examples of episodic memory loss

Cited by 40 publications

References 63 publications

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness

CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness

Persistence and plasticity in the human memory system: An empirical investigation of the overwriting hypothesis

Functional Amnesia: Clinical Description and Neuropsychological Profile of 10 Cases

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