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Retrograde amnesia: Clinical and methodological caveats
Abstract
Several clinical and methodological caveats are outlined as they pertain to retrograde amnesia research, and data relevant to these caveats are presented. Three caveats in particular are noted in relation to recently published cases of marked retrograde amnesia; (i) temporal lobe epilepsy may influence memory for news events; (ii) there may be additional, unsuspected pathology in cases of amnesia, such as those with cerebral hypoxia; (iii) degree of media exposure is closely related to performance on the types of news events memory tests that are commonly used in retrograde amnesia research.
... Accordingly, our test was constructed so that we could examine the effects of medial temporal lobe damage on recognition memory for semantic information across three decades (1970s-1990s). Kapur, Thompson, Kartsounis, and Abbott (1999) noted that the degree of exposure to media is closely related to performance on tests of memory for news events. Because there may be a difference in media exposure between controls and patients with a chronic illness, we elected to assess this potential confound using a short questionnaire designed by Kapur et al. (1999). ...
... Kapur, Thompson, Kartsounis, and Abbott (1999) noted that the degree of exposure to media is closely related to performance on tests of memory for news events. Because there may be a difference in media exposure between controls and patients with a chronic illness, we elected to assess this potential confound using a short questionnaire designed by Kapur et al. (1999). ...
... In the analyses of semantic information and naming performance, only those faces and names that were initially judged as familiar were used. Participants also answered six questions about their general media exposure, as described by Kapur et al. (1999; see Appendix B of the present study). ...
Memory for famous individuals was assessed by the use of a recognition test in which participants first made familiarity judgments, followed by forced-choice decisions to specific probes for identity. Patients with temporal lobe epilepsy (TLE) or excisions, 12 left hemisphere and 12 right hemisphere, and 18 control participants identified famous figures across 3 decades (1970s–1990s). Only patients with right TLE were impaired at familiarity judgments of faces; this deficit was evident only for the most recent decades. Both groups of patients, however, were impaired at naming famous faces and at providing semantic information about famous people. These findings suggest the integrity of temporal structures in both hemispheres is critical for retrieval of detailed semantic information about famous individuals.
... Daarom moeten publieke gebeurtenissentests constant bijgewerkt worden om bruikbaar te blijven. Bovendien blijkt dat de variabiliteit in kennis van nieuwsfeiten erg groot is, en dat deze kennis sterk correleert met intelligentie, opleidingsniveau en mediaconsumptie (Kapur, Thompson, Karsounis, & Abbott, 1998). Daardoor is het soms moeilijk retrograde amnesie te onderscheiden van een zeer beperkte algemene kennis. ...
... De gemiddelde score op de AMV (publieke gebeurtenissen) is ook niet laag, maar sommige normale controles blijken vrij laag te scoren (zie figuur 3), zodat het risico bestaat van overlap in score tussen deze normalen en patiënten met retrograde amnesie maar veel algemene kennis. Dit is een algemeen probleem van nieuwstesten, gevoelig als ze zijn voor interesse en opleidingsniveau (Kapur et al., 1998). (Klomps, 2001); data AGI van een steekproef van 28 normale controles (ongepubliceerde data); data NVT van een gestratificeerde steekproef van 70 normale controles (de Wilde, 2001). ...
... Bestaande tests in het buitenland blijken wat dat betreft vaak goed te voldoen. Zo hebben zowel publieke kennistesten, autobiografische testen als vocabulairetesten een goed genoege dateerbaarheid om een Ribot gradiënt op te pikken (Albert et al., 1979;Kapur et al., 1998;Kopelman, 1989;Squire et al., 1975b;Verfaellie et al., 1995), terwijl bijvoorbeeld de AMI patiënten met retrograde amnesie goed genoeg van controles 0 0.25 0.5 0.75 1 AMV AGI NVT onderscheidt om in de praktijk gebruikt te worden . Met de net ontwikkelde Nederlandstalige tests zijn trials begonnen of gepland met patiënten bij wie retrograde amnesie kan worden vermoed. ...
Voor retrograde amnesie zijn weinig tests ontwikkeld ’ tot voor kort was er zelfs geen voor het Nederlandse taalgebied. Het
construeren van zo'n test is nogal gecompliceerd. De test moet herinneringen toetsen die zowel dateerbaar als universeel zijn
binnen een normale populatie, voorwaarden die elkaar tot op zekere hoogte tegenspreken. In het buitenland zijn verscheidene
tests beschikbaar, die een beroep doen op algemene kennis, autobiografische herinneringen en neologismen. Van elk type is
er Nederland nu één in ontwikkeling. Of ze in de praktijk bruikbaar zijn hangt ervan af hoe goed patiënten met retrograde
amnesie onderscheiden kunnen worden van controleproefpersonen
... Thus, attempts to identify the role of the hippocampus on RA have produced conflicting and controversial results, which have led to extensive debate in the literature. For example, suggestions have been made that the patients reported above with extensive and ungraded RA without clear cortical involvement must have had cortical 'hidden pathology' (see for further discussion [1,28,52,67]). One possible problem which is often mentioned is that the neuronal dysfunction caused by ischaemia may be more extensive than the region of gross pathology [3,20]. ...
... The field of view was 10 cm and the resolution 7 mm FWHM. Decreased tracer uptake was seen throughout the right thalamus and possibly the right parietal region compared to the left (see for further details [28]). ...
... The patient was first referred to the Neuropsychology Department of the National Hospital for Neurology and Neurosurgery in September 1993 for evaluation of his memory difficulties. The results of this first assessment, together with an experimental investigation focusing on his amnesia, are reported elsewhere [28]. He has subsequently been reassessed on three different occasions. ...
For patients with hippocampal pathology, disagreement exists in the literature over whether retrograde amnesia is temporally limited or very extensive depending on whether the anatomical damage is restricted to this structure or also involves additional temporal cortex. We report a comprehensive assessment of retrograde and anterograde memory functions of a severely global amnesic patient (VC). We found that he presented with a remarkably extensive and basically ungraded retrograde amnesia. This impairment profoundly affected four decades preceding the onset of his amnesia and encompassed both non personal and personal facts and events. VC also presented with a severe anterograde amnesia and a deficit in the acquisition of new semantic knowledge in the post-morbid period. Detailed MRI volumetric measurements revealed gross abnormalities in both hippocampi which were markedly shrunken. Of relevance to the debate on retrograde amnesia were the observations that the volumes of both entorhinal cortices and the remainder of both temporal lobes were normal. These data suggest that the hippocampus is critical not only for the efficient encoding and hence normal recall of new information but also for the recall of episodic information acquired before the onset of amnesia. Our results are compatible with the view that retrograde amnesia is both extensive and ungraded when the damage is limited to the hippocampus.
... On the other hand, these two clusters of tests correlated only very weakly and nonsignificantly together, suggesting that they do indeed represent separable components of retrograde memory. The fact that IQ correlated significantly with the "more semantic" measures of remote memory suggests that education and intelligence contribute to scores on tests of famous faces or news events (a finding recently replicated by Kapur, Thompson, Kartsounis, & Abbot, 1999), whereas this is much less true of autobiographical memories. Returning to Figure 2 (please click here to see Figure 2 in colour), the cluster of subjects in the upper lefthand quadrant may reflect the fact that a combination of low IQ, poor education, and relatively mild amnesia is quite common, whereas the opposite pattern (bottom right-hand quadrant) is much less common-severe autobiographical memory loss in someone with good background semantic knowledge (high IQ and education). ...
... Moreover, few lesions exist in isolation (what I call "the myth of the pure lesion"), although neuropsychological reports commonly discount suggestions of additional pathology which do not conform to pre-existing models: hence, evidence of frontal lobe contributions to memory encoding and retrieval (Wheeler, Stuss, & Tulving, 1995) tended to be discounted until the advent of PET activation studies (Grasby et al., 1993). Furthermore, structural lesions commonly have widespread metabolic effects (Kapur et al., 1999;Kuhl et al., 1980;Reed et al., 1999) in which case, by what criteria are we to attribute causality to a particular pathological site? Brain infarction may produce secondary ischaemia elsewhere, and infarction is likely to occur in a patient whose cerebrovascular system is already compromised. ...
... Moreover, if dissociations are to be postulated, it has to be shown that (a) the patient does indeed fail on more than one task reflecting the purported deficit, i.e., the findings do not simply reflect chance variation in test performance, and (b) that the results cannot be explained in other terms. For example, poor recall for public or semantic knowledge may reflect low intelligence and education or prolonged illness (Kapur et al., 1999;Kopelman, 1989), whereas profoundly impaired autobiographical memory in the presence of surprisingly good semantic knowledge may reflect severe amnesia in the context of high premorbid intelligence or accomplishment. The important point is that alternative explanations should be sought for dissociations before they are attributed to particular sites of pathology, especially if the evidence of that pathology is only subtle. ...
A detailed critique of the literature on focal retrograde amnesia is provided. Some of the cases commonly cited in this literature had, in fact, severely impaired anterograde memory, most often involving visuospatial material. Other cases showed poor anterograde memory in more moderate or subtle form, begging the question of whether "like" had really been compared with "like" across the retrograde and anterograde domains: there may be alternative explanations for the observed patterns of performance. One suggestion is that these patients suffer an impairment of long-term consolidation, an attractive hypothesis but one which requires much more rigorous testing than has occurred to date and which implies that the underlying problem is not specific to retrograde memory. Moreover, within the literature on cases of focal retrograde amnesia, differing patterns of performance on tests of autobiographical memory or remote semantic knowledge have been reported, and sometimes these may have reflected factors other than the sites of lesions. Many of the most convincing cases in this literature have been those in whom there was an initially severe anterograde amnesia as well as an extensive retrograde loss: in these cases, the critical issue is what determines differential patterns of recovery across these domains-it is likely that both physiological and psychological factors are important. A second, somewhat different, group are patients with semantic dementia, who show a pronounced recency effect in remote memory but, in these cases, the most parsimonious explanation may be in terms of predominantly semantic/linguistic and/or strategic factors. A third group are those with transient epileptic amnesia but, in these cases, the memory gaps may reflect past (anterograde) ictal activity. A fourth group are those in whom psychogenic factors may well be relevant. Although it is difficult to "prove" psychological causation, the logical difficulties in attributing causation where brain lesions are either very subtle or multiple have been considerably underestimated in the neuropsychological literature. Given these problems, in uncertain or equivocal cases, it is as critical to present the relevant psychological data for the reader to evaluate as it is to provide the pertinent memory test scores: this is underemphasised in many of the studies reviewed. Publication of cases in the absence of such data may lead to faulty clinical, neuropsychological, and cognitive conclusions. Abbreviations : AA: anterograde amnesia; AMI: Autobiographical Memory Interview; PTA: posttraumatic amnesia; RA: retrograde amnesia; RMT: Recognition Memory Test; TEA: transient epileptic amnesia; TGA: transient global amnesia; WMS: Wechsler Memory Scale.
... Accordingly, our test was constructed so that we could examine the effects of medial temporal lobe damage on recognition memory for semantic information across three decades (1970s-1990s). Kapur, Thompson, Kartsounis, and Abbott (1999) noted that the degree of exposure to media is closely related to performance on tests of memory for news events. Because there may be a difference in media exposure between controls and patients with a chronic illness, we elected to assess this potential confound using a short questionnaire designed by Kapur et al. (1999). ...
... Kapur, Thompson, Kartsounis, and Abbott (1999) noted that the degree of exposure to media is closely related to performance on tests of memory for news events. Because there may be a difference in media exposure between controls and patients with a chronic illness, we elected to assess this potential confound using a short questionnaire designed by Kapur et al. (1999). ...
... In the analyses of semantic information and naming performance, only those faces and names that were initially judged as familiar were used. Participants also answered six questions about their general media exposure, as described by Kapur et al. (1999; see Appendix B of the present study). ...
Memory for famous individuals was assessed by the use of a recognition test in which participants first made familiarity judgments, followed by forced-choice decisions to specific probes for identity. Patients with temporal lobe epilepsy (TLE) or excisions, 12 left hemisphere and 12 right hemisphere, and 18 control participants identified famous figures across 3 decades (1970s-1990s). Only patients with right TLE were impaired at familiarity judgments of faces; this deficit was evident only for the most recent decades. Both groups of patients, however, were impaired at naming famous faces and at providing semantic information about famous people. These findings suggest the integrity of temporal structures in both hemispheres is critical for retrieval of detailed semantic information about famous individuals.
... De rares études de groupe ont rapporté des déficits de mémoire du passé chez des patients atteints d'épilepsie du lobe temporal (Barr et al. , 1990 ;Lah et al. , 2004 ;Viskonstas et al. , 2000 ;2002). Kapur et al. (1999), considérant uniquement la mémoire des faits publics, ont confirmé que l'épilepsie du lobe temporal (ELT) affectait particulièrement ce type de mémoire. ...
... La mémoire des faits publics est associée à l'exposition aux médias (Kapur et al. , 1999), qui fait partie de la vie quotidienne. Bien que la plupart des nouveaux événements soient rapidement oubliés, les quelques faits importants qui restent forment notre « mémoire historique ». ...
Background
Memory for the past has been much less explored than anterograde memory in temporal lobe epilepsy. No data are available about the course after surgical treatment. Moreover, case-reports showing isolated memory deficit for publics events with preserved autobiographical memory are notorious for their paucity.
Methods
We report the case of a patient with a left hippocampal lesion associated with intractable temporal lobe epilepsy. Comprehensive neuropsychological assessments were carried out before and after temporal lobectomy, stressing particularly memory for the past by means of standardised and tailor-made tests.
Results
The patient exhibited preserved memory for autobiographical events and facts but impaired scores on several public event tests, in the context of preserved general abilities.Furthermore, we found an accelerated forgetting rate for verbal and non verbal material.
Conclusion
Our findings suggest that the patient's impaired long-term consolidation might have contributed to the impaired performance on public event memory tests. We discuss the specific features of new events processing that may contribute to its increased vulnerability relative to autobiographical memory, in the event of accelerated forgetting.
... Variables such as age, gender, media consumption, and educational attainment are known to influence the retention of news events (Howes & Katz, 1988;Kapur et al., 1998;Klomps, 2001;Meeter et al., 2005;Rubin et al., 1999;Storandt et al., 1978). Here, we investigated whether such variables can also predict retention of categories of news, above and beyond general effects on performance. ...
... From the perspective of testing memory, effects of demographic variables on performance would count as bias if they would reflect differences in interest and not differences in memory functioning. The fact that media consumption is the strongest predictor of scores suggests that interest is indeed the stronger factor (Kapur et al., 1998;Meeter et al., 2005). Category-specific effects of demographic variables would be almost guaranteed to be due to differences in levels of interest (e.g., it is very unlikely that a person would have a memory system that was specifically suited to retain sports news). ...
Many tests of retrograde amnesia consist of questions on news events. It is therefore important to know how such questions are answered by normal adults. We analysed the retention of news events in a sample of 12,913 participants, who provided basic demographic information and subsequently answered questions about news events randomly sampled from a database. We investigated whether demographic variables could predict differences in the intake and retention of news from several categories, such as sports and business news. Although demographic variables did affect general performance on news questions, differential effects on specific categories were marginal. Gender influenced performance on questions about business news, both age and educational attainment affected performance on political news, and educational attainment also had an effect on performance on science news.
... Depression and anxiety was measured using the Hospital Anxiety and Depression Scale (Zigmond and Snaith, 1983). Media exposure, an important influence on public semantic memory, was also assessed (Kapur et al., 1999). ...
... Nevertheless, regardless of the reason for our finding, this study provides the first demonstration, in a group of patients with TEA, of impairments in public semantic memory; and it points to the sensitivity of the Dead-or-Alive Test as a measure of Brain 2010: Page 9 of 12 | 9 remote memory. Furthermore, the lack of significant difference between patients and controls on the Media Exposure Test (Kapur et al., 1999) suggests that the deficits cannot be attributed to this factor. ...
Transient epileptic amnesia is a form of temporal lobe epilepsy in which sufferers often complain of irretrievable loss of remote memories. We used a broad range of memory tests to clarify the extent and nature of the remote memory deficits in patients with transient epileptic amnesia. Performance on standard tests of anterograde memory was normal. In contrast, there was a severe impairment of memory for autobiographical events extending across the entire lifespan, providing evidence for the occurrence of 'focal retrograde amnesia' in transient epileptic amnesia. There was a milder impairment of personal semantic memory, most pronounced for midlife years. There were limited deficits of public semantic memory for recent decades. These results may reflect subtle structural pathology in the medial temporal lobes or the effects of the propagation of epileptiform activity through the network of brain regions responsible for long-term memory, or a combination of these two mechanisms.
... However, correlations with IQ were not signi¢cant for measures of autobiographical incidents and personal semantic' facts. Likewise, Kapur et al. (1999) found a trend in the same direction in healthy subjects between estimated premorbid IQ and a public events remote memory measure. Moreover, Kapur et al. (1999) also found that this fairly typical test of retrograde memory correlated even more closely with an estimate of media exposure, based on how often a subject watched the television news, read newspapers, etc. ...
... Likewise, Kapur et al. (1999) found a trend in the same direction in healthy subjects between estimated premorbid IQ and a public events remote memory measure. Moreover, Kapur et al. (1999) also found that this fairly typical test of retrograde memory correlated even more closely with an estimate of media exposure, based on how often a subject watched the television news, read newspapers, etc. ...
Retrograde amnesia in neurological disorders is a perplexing and fascinating research topic. The severity of retrograde amnesia is not well correlated with that of anterograde amnesia, and there can be disproportionate impairments of either. Within retrograde amnesia, there are various dissociations which have been claimed-for example, between the more autobiographical (episodic) and more semantic components of memory. However, the associations of different types of retrograde amnesia are also important, and clarification of these issues is confounded by the fact that retrograde amnesia seems to be particularly vulnerable to psychogenic factors. Large frontal and temporal lobe lesions have been postulated as critical in producing retrograde amnesia. Theories of retrograde amnesia have encompassed storage versus access disruption, physiological processes of 'consolidation', the progressive transformation of episodic memories into a more 'semantic' form, and multiple-trace theory. Single-case investigations, group studies and various forms of neuroimaging can all contribute to the resolution of these controversies.
... People who lived outside of the country in which the event occurred may not have been exposed to the material being tested. Exposure to news items may also vary based on interest (63). Further, questions regarding "recent" events will become outdated over time, requiring questionnaires to be updated frequently. ...
Studies of epilepsy patients provide insight into the neuroscience of human memory. Patients with remote memory deficits may learn new information but have difficulty recalling events from years past. The processes underlying remote memory impairment are unclear and likely result from the interaction of multiple factors, including hippocampal dysfunction. The hippocampus likely has a continued role in remote semantic and episodic memory storage over time, and patients with mesial temporal lobe epilepsy (TLE) are at particular risk for deficits. Studies have focused on lateralization of remote memory, often with greater impairment in left TLE, which may relate to verbal task demands. Remote memory testing is restricted by methodological limitations. As a result, deficits have been difficult to measure. This review of remote memory focuses on evidence for its underlying neurobiology, theoretical implications for hippocampal function, and methodological difficulties that complicate testing in epilepsy patients.
... We compared the patients' performance on the New Words Acquisition Test with the results reported by Milton et al. (Milton et al., 2010), and their performance on the Dead or Alive Test with that of their spouses. As IQ and media exposure both influence knowledge of public events (Kapur et al., 1999) we asked MB, PT and their spouses to rate both their level of interest in public events and to what extent they are well informed about these on a five point scale (not at all, a little, moderately, more than most, extremely). MB and his spouse are both educated to degree level and both describe themselves as 'moderately' interested in and well informed about public events; PT and his spouse have 21 and 18 years of education respectively, and while PT describes himself as 'extremely' interested in and well-informed about public events, his spouse is 'moderately' interested in them and 'better informed than most'. ...
Temporal lobe epilepsy (TLE) can be associated with a marked impairment of autobiographical memory. This is occasionally its presenting feature. We describe two individuals with severe epilepsy-associated autobiographical memory loss. Both MB and PT were reassured initially that their memory was intact on the basis of standard neuropsychological tests. Both have written detailed accounts of their symptoms. The key neuropsychological features of their cases are the relative normality of performance on standard memory tests, with preservation of semantic memory for impersonal information, in contrast to a profound amnesia for salient autobiographical episodes and an impoverishment of imaginative scene construction. First person accounts from these individuals illustrate the importance of autobiographical memory in sustaining a coherent sense of self, informing interpersonal relationships and supporting future thinking and problem-solving. These cases contribute to the growing evidence for a distinctive pattern of autobiographical memory loss associated with TLE, and indicate that it can take a severe form affecting both personal semantics and episodic recollection. Defining the phase of memory processing most relevant to this form of amnesia, and the roles of physiological and structural pathology, requires further research. The paper's title refers to the introspective ‘void’ highlighted by both MB and PT in their reports – in PT's words: ‘My primary symptom is the void that is my past’.
... Per converso, pazienti con lesioni destre temporo-mesiali o talamiche mostrano dei deficit di memoria selettivi per materiale non verbale (ad esempio Cipolotti e Bird, 2006;Daum e Ackermann, 1994;Parkin et al., 1994;Pigott e Milner, 1993;Speedie e Heilman, 1983;Turriziani et al., 2003). Kapur et al., 1999;Incisa della Rocchetta et al., 1996;Maguire et al., 1996;Turriziani et al., 2003). È interessante evidenziare che sono stati descritti pazienti con pattern opposto. ...
... In hypoxia, there are also reports of hypometabolism in the thalami and/or medial temporal lobes [88][89][90] . Thalamic hypometabolism was also reported in a severely amnesic patient with structural changes in the hippocampi 91 , and thalamic, retrosplenial, and medial temporal hypometabolism were found in a patient profoundly amnesic following MDMA ('Ecstasy') toxicity, either as a direct consequence of serotonin toxicity or of resulting hypoxia/ ischaemia 92 . ...
The impact of advanced brain imaging procedures in the field of human memory disorder is reviewed, with particular emphasis on current and potential applications that may impact upon the diagnosis and management of memory-disordered patients. While both advanced structural, resting physiological and functional physiological brain imaging procedures have been applied to conditions where memory disorder is a major feature, the specific implications of research findings for diagnosis and treatment in routine clinical practice remain tentative and promising, but not yet substantive enough to inform clinical decisions to a significant degree. In terms of diagnostic applications, several promising areas include dementia, epilepsy, and transient amnesic states. In the case of applications in treatment settings, advanced brain imaging procedures may help to monitor neural correlates of spontaneous recovery or progression of memory function, and may also help in the planning and monitoring of therapeutic intervention.
... In some patients, for example some of those with TEA, it is possible to be confident that remote memories had been successfully acquired as they were captured in family photographs that were reviewed regularly or had been repeatedly discussed. Second, even individuals with normal anterograde memory function differ markedly in their exposure to and interest in current events (Kapur et al., 1999). This is rarely taken into account in research studies. ...
Transient epileptic amnesia (TEA) is a form of epilepsy of which the principle manifestation
is recurrent, transient episodes of isolated memory loss. Although the phenomenon has been
recognised for over a century, it is scantily documented in the medical literature and is often
misdiagnosed by clinicians. Recent work has highlighted a number of apparently consistent
clinical features among the published cases. However, to date there has been no large,
systematic study of the condition. The aim of the work reported in this thesis was to
investigate a substantial number of prospectively recruited patients with TEA, and thus be
able to provide a detailed and authoritative description of its clinical, neuropsychological and
radiological characteristics.
Fifty patients with TEA were recruited from around the United Kingdom using established
diagnostic criteria, together with a group of matched healthy control subjects. Participants
underwent a clinical interview, comprehensive neuropsychological testing and structural
magnetic resonance imaging of the brain.
The study demonstrated the following features. TEA typically begins in later life. The
amnesic episodes are frequent, brief and often occur upon waking. They are characterised by
a mixed anterograde and retrograde amnesia, the anterograde component of which is often
incomplete. Attacks are commonly associated with olfactory hallucinations. They respond
well to anticonvulsant medication. Nevertheless, many patients complain of persistent
difficulties with memory. Despite generally performing well on standard tests of anterograde
memory, many patients show i) accelerated forgetting of new information over a three-week
delay and ii) temporally extensive deficits in autobiographical memory. TEA is associated
with subtle medial temporal lobe atrophy on magnetic resonance imaging. This atrophy
correlates with performance on standard memory tests, but not with long-term forgetting
rates or autobiographical memory deficits.
It is proposed that TEA is a distinctive syndrome of epilepsy, typically misdiagnosed at
presentation, caused by medial temporal seizure activity and associated with accelerated
long-term forgetting and autobiographical memory loss. These unusual forms of memory
impairment have been documented in other forms of epilepsy. They pose challenges to
current models of memory. The syndrome of TEA is therefore both clinically and
theoretically important.
... However, education would be expected to increase knowledge of public events either directly or through encouraging awareness of world events. Kapur, Thompson, Kartsounis, and Abbott (1999) reported that exposure to media may compromise tests of knowledge of people and events. In their study, score on a test of knowledge of news events correlated 0.76 (p < .001) ...
The article reviews research conducted with the Australian Remote Memory Test (ARMB) since its development first reported in 2001. Data from case studies and experimental investigations that have used the ARMB are summarised, and the use made of these data in reviews of the literature is noted. The ARMB has been found sensitive to disease processes such as herpes simplex, stroke, and epilepsy and lesion effects such as temporal lobectomy. The pattern of findings is consistent with current understanding of memory function. The studies have, however, pointed to factors that need to be considered in using the test, including patient medication and education level. Directions for future research with the test are briefly noted.
... Public semantic memory deficit has been specifically related to TLE. Crucial evidence was offered by Kapur et al.'s (1999) and recently by Haag et al.'s (2010) investigations showing unambiguously an impaired public semantic memory score exclusively in the TLE patient group relative to an extra-temporal epilepsy group. Moreover, it has been shown that public events representations are likely to be stored in extensive extra-hippocampal, neocortical regions (e.g., St-Laurent et al., 2009) and, more precisely, that loss of semantic aspects of memory reflects damage to temporal neocortex, particularly, in the left hemisphere (Winocur et al., 2010). ...
... Kartsounis et al. offered a note of caution, suggesting that, although detailed MRI scanning indicated only circumscribed structural damage in their patient, it was not possible to exclude subtle histological changes in other areas or remote hypoactivation effects of the hippocampal infarcts, particularly with regard to adjacent cortical areas and the mammillo-thalamic system. A more recent PET study of this patient (Kapur et al., 1999) showed additional pathology in the right thalamus, and so the role of the hippocampal damage in this patient's retrograde amnesia remains uncertain. ...
The role of the hippocampus in retrograde amnesia remains controversial and poorly understood. Two cases are reported of discrete bilateral hippocampal damage, one of which was a rare case of limbic encephalitis secondary to the human herpes virus 6. Detailed memory testing showed marked anterograde memory impairment, but only mild, temporally-limited retrograde amnesia that covered a period of several years in both autobiographical and factual knowledge domains. The absence of extensive retrograde amnesia in these two cases points to a time-limited role for the hippocampus in the retrieval of retrograde memories, and suggests that entorhinal, perirhinal, parahippocampal, or neocortical areas of the temporal lobe may be more critical than the hippocampus proper for long-term retrograde memory functioning. Our findings offer general support to theories of memory consolidation that propose a gradual transfer of memory from hippocampal to neocortical dependency. Hippocampus 1999; 9:247–254. © 1999 Wiley-Liss, Inc.
... Substantial research suggests that episodic and semantic autobiographical memory can be dissociated (Tulving, 2002; Wheeler, Stuss & Tulving, 1997). Moreover, neuropsychological studies of patients (Moscovitch et al., 2005; Gilboa et al., 2005; Kapur, 1999), and functional neuroimaging studies of healthy adults (Maguire, 2001; Svoboda et al., 2006), suggest that the two forms of autobiographical memory differ in nature of the recruitment of brain regions, with medial temporal lobes especially involved in episodic, and lateral temporal cortex (particularly on the left) especially involved in semantic, autobiographical memory. Past research investigating autobiographical memory in normal aging has shown that agerelated decline is particularly marked in episodic, as compared to semantic, autobiographical memory (Levine et al., 2002; Piolino et al., 2002). ...
Amnestic mild cognitive impairment (aMCI) is characterized by decline in anterograde memory as measured by the ability to learn and remember new information. We investigated whether retrograde memory for autobiographical information was affected by aMCI. Eighteen control (age 66-84 years) and 17 aMCI (age 66-84 years) participants described a personal event from each of the five periods across the lifespan. These events were transcribed and scored according to procedures that separate episodic (specific happenings) from semantic (general knowledge) elements of autobiographical memory. Although both groups generated protocols of similar length, the composition of autobiographical recall differentiated the groups. The aMCI group protocols were characterized by reduced episodic and increased semantic information relative to the control group. Both groups showed a similar pattern of recall across time periods, with no evidence that the aMCI group had more difficulty recalling recent, rather than remote, life events. These results indicate that episodic and semantic autobiographical memories are differentially affected by the early brain changes associated with aMCI. Reduced autobiographical episodic memories in aMCI may be the result of medial temporal lobe dysfunction, consistent with multiple trace theory, or alternatively, could be related to dysfunction of a wider related network of neocortical structures. In contrast, the preservation of autobiographical semantic memories in aMCI suggests neural systems, such as lateral temporal cortex, that support these memories, may remain relatively intact.
... In some patients, for example some of those with TEA, it is possible to be confident that remote memories had been successfully acquired as they were captured in family photographs that were reviewed regularly or had been repeatedly discussed. Second, even individuals with normal anterograde memory function differ markedly in their exposure to and interest in current events (Kapur et al., 1999). This is rarely taken into account in research studies. ...
Complaints of memory difficulties are common among patients with epilepsy, particularly with temporal lobe epilepsy where memory-related brain structures are directly involved by seizure activity. However, the reason for these complaints is often unclear and patients frequently perform normally on standard neuropsychological tests of memory. In this article, we review the literature on three recently described and interrelated forms of memory impairment associated with epilepsy: (i) transient epileptic amnesia, in which the sole or main manifestation of seizures is recurrent episodes of amnesia; (ii) accelerated long-term forgetting, in which newly acquired memories fade over days to weeks and (iii) remote memory impairment, in which there is loss of memories for personal or public facts or events from the distant past. Accelerated long-term forgetting and remote memory impairment are common amongst patients with transient epileptic amnesia, but have been reported in other forms of epilepsy. Their presence goes undetected by standard memory tests and yet they can have a profound impact on patients' lives. They pose challenges to current theoretical models of memory. We discuss the evidence for each of these phenomena, as well as their possible pathophysiological bases, methodological difficulties in their investigation and their theoretical implications.
... If dissociations are to be postulated, it ought to be shown that the patient fails on more than one task re¯ecting a purported de®cit, otherwise the ®ndings may simply re¯ect chance variation in test performance. Secondly, some patterns of ®ndings can be explained in other terms: for example, poor recall for public or semantic knowledge may re¯ect low intelligence or poor education and media exposure (Kopelman, 1989; Kapur et al., 1999), whereas profoundly impaired autobiographical memory retrieval in the presence of surprisingly good semantic knowledge might re¯ect severe frontal/executive impairment (Kopelman, 2000a). (iv) The most convincing cases in this literature have been those in whom there was an initially severe anterograde amnesia, as well as an extensive RA, particularly following head injury. ...
This paper reviews disorders of memory. After a brief survey of the clinical varieties of the amnesic syndrome, transient and persistent, selected theoretical issues will be considered by posing a series of questions. (i) What is impaired and what is spared in anterograde amnesia? (ii) Do temporal lobe, diencephalic and frontal lobe amnesias differ? (iii) How independently semantic is semantic memory? (iv) What determines the pattern and extent of retrograde memory loss? (v) Can retrograde amnesia ever be "isolated"? (vi) Does psychogenic amnesia involve the same mechanisms as organic amnesia? (vii) How and when do false memories arise? Commonalities as well as differences across separate literatures will be emphasized, and the case for a more "dynamic" (interactionist) approach to the investigation of amnesia will be advocated.
... First of all, the association may be too weak to reach statistical significance. Secondly, the prevalence of psychiatric disorders in the TLE patients is possibly underestimated because of memory impairments of these patients caused by the very nature of their brain disorder (24). Thirdly and maybe more important, the establishment of the diagnosis TLE and extra-TLE is hard to make accurately. ...
The purpose of this study was to determine the prevalence of psychiatric disorders in Dutch patients with epilepsy in comparison with epidemiological data on a representative sample of the Dutch population. The Composite International Diagnostic Interview (CIDI) was used to determine the prevalence of psychiatric disorders in 209 epilepsy patients and compared with findings in the general Dutch population. The prevalence in temporal lobe epilepsy (TLE) and extra-temporal lobe epilepsy (extra-TLE) was also compared. Psychiatric disorders most frequently found in patients with epilepsy were anxiety and mood disorders. The last-year prevalence of these disorders was 25% for anxiety disorders and 19% for mood disorders. Compared with the general Dutch population, the prevalence of these disorders was significantly higher in epilepsy. No differences were found between patients with TLE and extra-TLE. It can be concluded that patients with epilepsy admitted to a tertiary epilepsy center suffer more often from mood and anxiety disorders than the general population.
... It does not exclude an alternative explanation, however, namely that semantic memory tests are sensitive to crystallized intelligence as purportedly measured by the NART (the fact that the NVT and NART also correlate within the normal control group supports this alternative). Indeed, tests of retrograde amnesia typically correlate with intelligence (Kapur et al., 1998). ...
Patients with mild to moderate Alzheimer's disease and normal controls were tested on a retrograde amnesia test with semantic content (Neologism and Vocabulary Test, or NVT), consisting of neologisms to be defined. Patients showed a decrement as compared to normal controls, pointing to retrograde amnesia within semantic memory. No evidence for a gradient within this amnesia was found, although one was present on an autobiographic test of retrograde amnesia that had a wider time scale. Several explanations for these results are presented, including one that suggests that extended retrograde amnesia and semantic memory deficits are in fact one and the same deficit.
... Given the notorious paucity of such a pattern of performance, it is worth recalling that two of the four reported patients suffered from epilepsy (Kapur et al., 1989(Kapur et al., , 1997. Memory for public events is associated with media exposure (Kapur et al., 1999), which is a part of everyday life. Though most news events are rapidly forgotten, the few important facts that remain shape our stored public events memory, which affects an important part of our awareness of the surrounding world and allows us to share cultural community interests (Brown, 1990). ...
Highly selective memory impairment for public events was demonstrated in a patient (JR), who suffered from temporal lobe epilepsy (TLE). We successfully trained JR's memory for a set of news events and discuss, on those bases, the characteristics of news events processing that may have contributed to its increased vulnerability relative to autobiographical memory (AbM).
... 1). An 18 FDG PET scan showed decreased tracer uptake in the right thalamus and possibly the right parietal region compared with the left (Kapur et al., 1999). In a quantitative anatomical study of VC's brain based on volumetric region of interest measurements, gross abnormalities were revealed in both hippocampi which were markedly shrunken throughout their entire length (Cipolotti et al., 2001). ...
Bilateral hippocampal pathology typically results in significant memory problems. Despite apparently similar structural damage, patients with such lesions can differ in the pattern of impairment and preservation of memory functions. Previously, an fMRI study of a developmental amnesic patient whose anoxic hippocampal damage was incurred perinatally revealed his residual hippocampal tissue to be active during memory retrieval. This hippocampal activity was apparent during the retrieval of personal and general facts relative to a control task. In this study, we used a similar fMRI paradigm to investigate whether residual hippocampal activation was present also in patient VC with adult-acquired anoxic hippocampal pathology. VC's performance and reaction times on the experimental personal and general fact tasks were comparable to age-matched control subjects. However, in contrast to the elderly control sample and the previous developmental amnesic patient, his residual hippocampal tissue did not show activation changes during the experimental tasks. This finding indicates that patient VC's successful retrieval of personal and general facts was achieved without a significant hippocampal contribution. It further suggests that the hippocampal activation observed in the elderly controls and previous developmental amnesic patient was not necessary for successful task performance. The reason for this difference in hippocampal responsivity between VC and the developmental amnesic patient remains to be determined. We speculate that it may relate to the age at which hippocampal damage occurred reflecting plasticity within the developing brain, or to cognitive differences between VC, the developmental amnesic patient, and the control subjects.
... In addition, we report the findings from two new investigations (VBM and spetroscopy). A resting FGD PET scan showed, in addition to the hippocampal lesion, less signal return from the right thalamus and possibly the right parietal region (Kapur et al., 1999). However, there was neither analogous sign of structural abnormality on the two qualitative MRI scan examinations nor, more critically, of neuronal dysfunction of the thalamus on the magnetic resonance spectroscopy. ...
In the amnesia literature, disagreement exists over whether anterograde amnesia involves recollective-based recognition processes and/or familiarity-based ones depending on whether the anatomical damage is restricted to the hippocampus or also involves adjacent areas, particularly the entorhinal and perirhinal cortices. So far, few patients with well documented anatomical lesions and detailed assessment of recollective and recognition performance have been described. We report a comprehensive neuroanatomical assessment and detailed investigation of the anterograde memory functions of a previously described severe amnesic patient (VC). The results of four previously published neuroradiological investigations (resting PET, qualitative MRIs, volumetric MRI and functional MRI) together with the results of two new investigations (voxel-based morphometry and magnetic resonance spectroscopy) are presented. The consistent finding across these different qualitative and quantitative examinations of VC's brain has shown that there is primarily structural and functional abnormality located selectively in the hippocampus bilaterally. Marked impairments in both verbal and non-verbal recall and recognition standardized memory tests were documented in the context of VC's intact cognitive profile and normal semantic memory. The results of five new experimental recognition memory tests tapping recollection and familiarity using verbal, topographical (buildings and landscapes) and unknown human faces memoranda revealed striking differential effects according to the type of stimuli used. A receiver operating characteristic analysis revealed that VC's recollective- and familiarity-based recognition processes were well preserved for unknown human faces. In contrast, recollective-based recognition for verbal and topographical material was at floor. Familiarity-based recognition was also impaired, significantly below controls for verbal and buildings memoranda and quite weak, although not reaching significance, for landscapes. These data suggest that the hippocampus is involved in recollective processes of verbal and topographical stimuli. It also plays an appreciable role in familiarity processes for these stimuli. However, recollection and familiarity of human faces appear not to depend on this region.
... Given the notorious paucity of such a pattern of performance, it is worth recalling that two of the four reported patients suffered from epilepsy (Kapur et al., 1989(Kapur et al., , 1997. Memory for public events is associated with media exposure (Kapur et al., 1999), which is a part of everyday life. Though most news events are rapidly forgotten, the few important facts that remain shape our stored public events memory, which affects an important part of our awareness of the surrounding world and allows us to share cultural community interests (Brown, 1990). ...
Memory for the past has been much less explored than anterograde memory in temporal lobe epilepsy. No data are available about the course after surgical treatment. Moreover, case-reports showing isolated memory deficit for publics events with preserved autobiographical memory are notorious for their paucity.
We report the case of a patient with a left hippocampal lesion associated with intractable temporal lobe epilepsy. Comprehensive neuropsychological assessments were carried out before and after temporal lobectomy, stressing particularly memory for the past by means of standardised and tailor-made tests.
The patient exhibited preserved memory for autobiographical events and facts but impaired scores on several public event tests, in the context of preserved general abilities. Furthermore, we found an accelerated forgetting rate for verbal and non verbal material.
Our findings suggest that the patient's impaired long-term consolidation might have contributed to the impaired performance on public event memory tests. We discuss the specific features of new events processing that may contribute to its increased vulnerability relative to autobiographical memory, in the event of accelerated forgetting.
This article attempts a synthesis of the range of disorders that have been subsumed under the rubric of retrograde amnesia. At a functional level, it is possible to make distinctions between various forms of retrograde amnesia, including a distinction between episodic amnesia for personally experienced events and semantic retrograde amnesia for components of knowledge, such as those relating to people and events. At an anatomical level, discrete lesions to limbic-diencephalic structures usually result in a limited degree of retrograde amnesia. Marked episodic or marked semantic retrograde amnesia is usually associated with significant involvement of cortical and neocortical structures. Retrograde amnesia is a functionally heterogeneous rather than a unitary phenomenon. Discontinuities and dissociations found in published studies point to the potential fractionation of retrograde amnesia into component disorders, each with its own neural profile.
Novel tests of semantic memory (SM)—for example, memory for news events (NE; news facts) or famous personalities—are useful for estimating the severity of retrograde amnesia. Individuals with mild cognitive impairment exhibit relatively intact SM/language on traditional neuropsychological tests but exhibit consistent impairment on novel tests of SM, suggesting novel SM tests are dissimilar from traditional SM tests. To identify the relationship between NE memory and traditional cognitive measures, older adults ( N = 51) completed a traditional neuropsychological battery and the Retrograde Memory News Events Test (RM-NET; a new test that robustly measures NE memory across the adult life span with high temporal resolution), and the relationship between performance on these tests was examined. Total RM-NET scores were more closely aligned with episodic memory scores than SM scores. The strength of the association between NE scores and episodic memory scores decreased as the age of NE memory increased. Tests of news events appear to reflect performance on traditional tests of episodic memory rather than SM, especially when recent news events are tested.
p>Our understanding of the mechanisms underlying very long-term memory impairments remains rather limited. The aim of this thesis is to clarify the nature of various distinctive forms of very long-term memory disorder and to shed light on the mechanisms that give rise to these syndromes.
Chapter 1 provides a review of the relevant literature. Chapter 2 presents three sets of studies examining the nature and extent of retrograde amnesia following damage to temporal lobe and diencephalic structures. The extent to which medial temporal lobe structures are involved in the retrieval of autobiographical event memories across the lifetime is considered. The findings from these studies suggest that the hippocampal complex is critical to the ability to mentally re-experience or 'replay' events over a very extended period of time and probably as far back as childhood. These findings provide support for Multiple Trace Theory (Nadel and Moscovitch, 1997), and are less supportive of predictions derived from the Standard Consolidation Model of memory (Squire and Alvarez, 1995; Murre, 1996).
Chapter 3 is concerned with (i) the circumstances under which extensive retrograde amnesia may occur in the absence of anterograde memory deficit and (ii) the dissociation of episodic and semantic retrograde amnesia. Two cases are studied. The first case, a patient with cerebral vasculitis, presented with a severe impairment in autobiographical episodic memory, with normal anterograde memory. The second case presented with a progressive impairment in her ability to recognise familiar faces and a loss of knowledge of people in the presence of intact autobiographical memory. Although the findings from these cases highlight the dissociation of episodic and semantic memory, it is argued that in the undamaged human brain there is a complex and dynamic interaction between the experiential and factual components of long-term memory. Chapter 4 presents two studies of very long-term anterograde memory.</p
p>Memory has been extensively studied in epilepsy. There are numerous accounts of memory impairments being found, particularly for people with temporal lobe epilepsy. Many discrepancies are, however, also evident. The first paper outlines the literature on memory problems in epilepsy. It focuses on the impairments reported in people with temporal lobe epilepsy in neuropsychological studies and cognitive neuroscience research and reviews the evidence concerning the presence and type of memory difficulties. Attention is then turned to the role of other factors in contributing to these difficulties, including epilepsy-related variables and psychological factors. The main conclusion drawn is that studies have not adequately acknowledged the possible role of these other factors when exploring memory impairments which presents a major methodological problem and more constrained studies are required to allow an understanding of the deficits experienced.
The second paper describes a study which investigated the presence of remote memory loss in people with temporal lobe epilepsy. A mild remote memory impairment was found for people with left temporal lobe epilepsy for both episodic autobiographical memory and semantic memory for public events. Support was given to the view that more sensitive tests of remote memory are required which allow the detection of subtle differences in performance. The need for future research with improved methodologies is discussed along with the potential clinical implications of such research.</p
The acquisition of new semantic memories is sometimes preserved in patients with hippocampal amnesia. Robust evidence for this comes from case reports of developmental amnesia suggesting that low-to-normal levels of semantic knowledge can be achieved despite compromised episodic learning. However, it is unclear whether this relative preservation of semantic memory results from normal acquisition and retrieval or from residual episodic memory, combined with effortful repetition. Furthermore, lesion studies have mainly focused on the hippocampus itself, and have seldom reported the state of structures in the extended hippocampal system. Preserved components of this system may therefore mediate residual episodic abilities, contributing to the apparent semantic preservation. We report an in-depth study of Patient KA, a 27-year-old man who had severe hypoxia at birth, in which we carefully explored his residual episodic learning abilities. We used novel speeded recognition paradigms to assess whether KA could explicitly acquire and retrieve new context-free memories. Despite a pattern of very severe amnesia, with a 44-point discrepancy between his intelligence and memory quotients, KA exhibited normal-to-superior levels of knowledge, even under strict time constraints. He also exhibited normal-to-superior recognition memory for new material, again under strict time constraints. Multimodal neuroimaging revealed an unusual pattern of selective atrophy within each component of the extended hippocampal system, contrasting with the preservation of anterior subhippocampal cortices. A cortical thickness analysis yielded a pattern of thinner but also thicker regional cortices, pointing toward specific temporal lobe reorganization following early injury. We thus report the first case of superior explicit learning and memory in a severe case of amnesia, raising important questions about how such knowledge can be acquired.
Many theories of declarative memory propose that it is supported by partially separable processes underpinned by different brain structures. The hippocampus plays a critical role in binding together item and contextual information together and processing the relationships between individual items. By contrast, the processing of individual items and their later recognition can be supported by extrahippocampal regions of the medial temporal lobes, particularly when recognition is based on feelings of familiarity without the retrieval of any associated information. These theories are domain-general in that “items” might be words, faces, objects, scenes, etc. However, there is mixed evidence that item recognition does not require the hippocampus, or that familiarity-based recognition can be supported by extrahippocampal regions. By contrast, there is compelling evidence that in humans, hippocampal damage does not affect recognition memory for unfamiliar faces, whilst recognition memory for several other stimulus classes is impaired. I propose that regions outside of the hippocampus can support recognition of unfamiliar faces because they are perceived as discrete items and have no prior conceptual associations. Conversely, extrahippocampal processes are inadequate for recognition of items which (a) have been previously experienced, (b) are conceptually meaningful, or (c) are perceived as being comprised of individual elements. This account reconciles findings from primate and human studies of recognition memory. Furthermore, it suggests that while the hippocampus is critical for binding and relational processing, these processes are required for item recognition memory in most situations.
Im klinisch-neurowissenschaftlichen Bereich wird Vergessen meist mit Amnesie gleichgesetzt, wobei der Terminus „Amnesie“ vielfältige Bedeutung haben kann: Er kann sowohl den vollständigen Verlust der eigenen Erinnerung meinen („retrograde Amnesie“) als auch das Fehlen von Erinnerung an bestimmte Ereignisse, bestimmte Lebensepochen, bestimmtes Material etc. als auch die Unfähigkeit, sich neues Material bleibend anzueignen (anterograde Amnesie). Entsprechend vielfältig sind die mit Amnesien verbundenen Störungsbilder: großflächige Hirnschäden, die zu Demenzen führen, distinkte Hirnschäden, die mit anterograden (und teilweise auch mit retrograden) Amnesien verbunden sind, und funktionelle oder dissoziative Amnesien, die teilweise reversibel sind und deswegen auch als mnestisches Blockadesyndrom bezeichnet werden. Gerade dieser letzte – psychogene – Bereich ist schon seit Sigmund Freud mit vergessensnahen Phänomenen wie Verdrängen, Täuschen, Fehlerinnerungen haben oder Nicht-vergessen-Können verbunden. Alle diese Phänomene werden – auch anhand von Beispielsfällen und eigenen Daten – diskutiert.
This chapter reviews the principles of assessment of perceptual disorders, auditory recognition deficits, tactile recognition deficits, and visual object recognition deficits. The implicit assumption is that visual object recognition skills have a hierarchical and parallel organization. In ordinary clinical practice however, object recognition disorders are 'random'. The question arises as to where a clinician should start when assessing a patient with object and/or face recognition problems. The first consideration is to obtain information on potential sensory problems, visuospatial neglect, aphasia, etc. that may at least partly account for perceptual/agnosic deficits. As a general rule, clinicians should be alert to the complaints and errors patients make during other tasks involving picture interpretation. If the patient fails these tests, there is no need for tests of visual agnosias either of the aperceptive or associative type - any agnosia diagnosed in this context would be 'pseudoagnosia'.
Traumatic brain injury (TBI) is a major cause of death and disability, and therefore an important health and socioeconomic problem for our society. Individuals surviving from a moderate to severe TBI frequently suffer from long-lasting cognitive deficits. Such deficits include different aspects of cognition such as memory, attention, executive functions, and awareness of their deficits. This chapter presents a review of the main neuropsychological and neuroimaging studies of patients with TBI. These studies found that patients evolve differently according to the severity of the injury, the mechanism causing the injury, and the lesion location. Further research is necessary to develop rehabilitation methods that enhance brain plasticity and recovery after TBI. In this chapter, we summarize current knowledge and controversies, focusing on cognitive sequelae after TBI. Recommendations from the Common Data Elements are provided, with an emphasis on diagnosis, outcome measures, and studies organization to make data more comparable across studies. Final considerations on neuroimaging advances, rehabilitation approaches, and genetics are described in the final section of the chapter.
© 2015 Elsevier B.V. All rights reserved.
Retrograde amnesia (RA) refers to loss of memory for events or facts which preceded the onset of an illness or injury. This chapter discusses the relationship of structural brain pathology to RA, dissociations within RA, the associations/correlates of RA, the relationship between (and putative independence of) RA and anterograde amnesia (AA), the functional neuroimaging of RA, and theories of RA. The chapter describes putative influence of psychogenic factors on RA. Various methods of empirical investigation are employed to examine RA in neurological patients. Frontal and temporal lobe lesions can give rise to an extensive retrograde amnesia. Diencephalic lesions are also associated with a temporally graded RA, although most commonly in association with concurrent frontal lobe pathology. In this chapter, various dissociations in RA are considered, including that between autobiographical and the more semantic aspects of RA. Importantly, recent studies have investigated the putative interaction between these components of memory. The status of disproportionate or “focal” RA remains controversial. The associations and correlates of retrograde memory loss also need greater consideration than they often receive—not only in terms of cognitive factors such as IQ and executive function, but also psychosocial factors such as education and media exposure, as well as the influence of affective valence and salience on memory retrieval.
Kopelman offers an invaluable and comprehensive review of empirical and theoretical issues relating to focal retrograde amnesia and related conditions. He makes two main points: (1) That many of the published cases of focal retrograde amnesia in fact showed significant anterograde memory impairment, and thus should strictly not be classified as cases of focal retrograde amnesia; (2) that there are hazards in attributing causality in patients with retrograde amnesia, especially those with a major autobiographical component. In the case of his first point, I suggest that his observations are a matter of interpretation, essentially revolving around the defining criteria for the selection of memories to be compared and for regarding one set of memories as "disproportionately impaired" compared to the other. With regard to the second point, however, I largely concur with his observations, adding some reservations of my own. I conclude that although some patients with focal retrograde amnesia may represent a diagnostic dilemma when it comes to attributing causality, those who are shown to have a clear neural basis to their memory loss provide an avenue for exploring the brain's plasticity in accommodating the formation of new memories despite the loss of equivalent old memories.
Het proefschrift beschrijft de relatie tussen epilepsie en psychiatrische stoornissen. Voor het onderzoek werden zowel klinische als poliklinische patiënten met epilepsie onderzocht op het voorkomen van DSM as I klinische stoornissen en as II persoonlijkheidsstoornissen. De resultaten werden vergeleken met controlegroepen uit de ‘normale’ bevolking. Eveneens werd onderzocht of er een relatie is tussen psychiatrische stoornissen en specifieke epilepsiesyndromen. Het onderzoek wees uit dat patiënten met epilepsie vaker angst- en stemmingsstoornissen hebben vergeleken met mensen in de algemene bevolking. Ook werd geconstateerd dat epilepsiepatiënten meer trekken van persoonlijkheidsstoornissen vertonen vergeleken met de controlegroep uit de algemene bevolking (met name cluster C persoonlijkheidsstrekken). Uitgebreid onderzoek naar de relatie tussen psychiatrische stoornissen en epilepsiesyndromen liet geen verschillen zien tussen patiënten met epilepsie vanuit de temporaalkwab (TLE) en patiënten waarbij de epilepsie niet vanuit de temporaalkwab ontstaat (extra-TLE). Wat wel werd gevonden was dat over het algemeen meer psychiatrische problemen werden gevonden bij de patiënten met een hogere aanvalsfrequentie en een kortere duur van de epilepsie. Gezegd kan worden dat patiënten die relatief kort epilepsie hebben en waarbij de aanvallen nog niet onder controle zijn, dat deze patiëntgroep het grootste risico loopt om psychische klachten te ontwikkelen.
Autobiographical memory includes the retrieval of personal semantic data and the remembrance of incident or episodic memories. In retrograde amnesias, it has been observed that recall of autobiographical memories of recent events is poorer than recall of remote memories. Alzheimer's disease (AD) may also be associated with a temporal gradient (TG) in memory decline, though studies have yielded inconsistent results on this point. They have also yielded inconsistent results on whether AD might differentially affect semantic and episodic remembrance. Here, we compared autobiographical memory of childhood, early adulthood, and recent life among healthy control (HC) subjects, patients with early AD, and patients with amnesic mild cognitive impairment (aMCI). Both the aMCI and AD patients exhibited declines in recall of autobiographical incidents and semantic information. In AD patients, both components of autobiographical memory had a clear TG, with better preservation of memories of childhood than those of early adulthood and recent life. The TG of autobiographical memory decline in AD patients is more compatible with the Cortical Reallocation Theory than with the Multiple Trace Theory of memory consolidation. In contrast to AD patients, aMCI patients exhibited impaired recall of personal facts and autobiographical incidents relating only to recent life. The significant decline in autobiographical memory for recent life that occurred in aMCI patients suggests that deterioration of consolidation of personal facts and events begins with commencement of functional impairment in the hippocampus.
Bilateral damage to the human hippocampus profoundly impairs the ability to form long-term, consciously accessible memories, producing a classic amnesic syndrome. However, the effect of hippocampal damage on our ability to recognize items via a feeling of familiarity is hotly disputed. Dual-process theory predicts no effect, whereas declarative memory theory predicts impairment of all types of recognition memory. Here, we demonstrate a striking material specificity in the effect of focal hippocampal damage: Recognition memory is impaired for words but intact for faces. The latter finding is incompatible with declarative memory theory, whereas the former constrains dual-process theory by revealing the limitations of postulated extrahippocampal familiarity-based processes. We suggest that the hippocampus boosts recognition of well-known stimuli (high-frequency words) by activating pre-experimental associations that enrich the context of their presentation. By contrast, recognition memory for some kinds of previously unfamiliar stimuli (unfamiliar faces) may be supported by extrahippocampal familiarity-based processes, at least over short intervals.
Patients with epileptic seizures (ES) and especially those with temporal lobe epilepsy (TLE) share many symptoms with patients with pseudo-epileptic seizures (PES), and the differentiation between them is often difficult There is growing evidence that a subgroup of PES patients suffer from a dissociative disorder. It is recognized that dissociative symptoms pertain to both psychological and somatoform components of experience. Questionnaires assessing dissociation might provide positive criteria for the diagnosis of PES. In this study, the Dissociation Questionnaire (DIS-Q) and the Somatoform Dissociation Questionnaire (SDQ-20) were administered to patients with ES (TLE, non-TLE) and PES. To control for the influence of general psychoneurotic complaints, the SCL-90 was administered. Apart from this, answers on a trauma questionnaire were related to the diagnosis. Results showed that PES patients scored significantly higher on the SDQ-20, also after correction with the SCL-90, and no difference was found on the DIS-Q. Also, PES patients significantly more often reported sexual traumatic experiences. A logistic regression revealed that results on the SDQ-20 have no independent value in addition to the contribution of gender, age, age at seizure onset, and the presence of sexual abuse in the prediction of the diagnosis. In conclusion, somatoform and not psychological dissociative symptoms are characteristic for PES patients in comparison to ES patients. Other measures are needed within the framework of the differential diagnosis between PES and ES.
Clinical and normal psychology have had a long tradition of close interaction in British psychology. The roots of this interplay may predate the development of the British Psychological Society, but the Society has encouraged and supported this line of research since its inception. One fundamental British insight has been to consider the evidence from pathology as a potential constraint on theories of normal function. In turn, theories of normal function have been used to understand and illuminate cognitive pathology. This review discusses some of the areas in which clinical contributions to cognitive theory have been most substantial. As with other contributions to this volume, attempts are also made to read the runes and anticipate future developments.
This article reviews 147 cases of amnesia following damage including the hippocampus or fornix as reported in 179 publications. The aetiology, mnestic abilities and reference(s) are tabulated for each case. Consistent findings across cases include the association of bilateral hippocampal damage with a deficit in anterograde episodic memory combined with spared procedural and working memory. The limited nature of retrograde amnesia following lesions to the fornix is also noted. Less consistent and thus more controversial findings, include effects of lesion size or laterality, deficits in semantic memory or familiarity-based recognition and the extent of retrograde amnesia. The evidence concerning these issues is reviewed across cases.
There are many controversies concerning the structural basis of retrograde amnesia (RA). One view is that memories are held briefly within a medial temporal store ("hippocampal complex") before being "consolidated" or reorganised within temporal neocortex and/or networks more widely distributed within the cerebral cortex. An alternative view is that the medial temporal lobes are always involved in the storage and retrieval (reactivation) of autobiographical memories (multiple trace theory). The present study used quantitative magnetic resonance imaging (MRI) in 40 patients with focal pathology/volume loss in different sites, to examine the correlates of impairment on three different measures of RA. The findings supported the view that widespread neural networks are involved in the storage and retrieval of autobiographical and other remote memories. Brain volume measures in critical structures could account for 60% of variance on autobiographical memory measures (for incidents and facts) in diencephalic patients and for 60-68% of variance in patients with frontal lesions. Significant correlations with medial temporal lobe volume were found only in the diencephalic group, in whom they were thought to reflect thalamic changes, but not in patients with herpes encephalitis or hypoxia in whom the temporal lobes were particularly implicated. The latter finding fails to support one of the main predictions of multiple trace theory, as presently expounded.
This article explores the recall, item recognition, and associative recognition memory of patient B.E., whose pattern of retrograde amnesia was reported by Kapur and Brooks (1999; Hippocampus 9:1-8). Structural magnetic resonance imaging (MRI) has shown that B.E. has bilateral damage restricted to the hippocampus. The structural damage he had sustained was accompanied by bilateral hypoperfusion of the temporal lobe, revealed by positron emission tomography (PET), and which single photon emission computed tomography (SPECT) suggested was greater in the left than the right temporal lobe. B.E. showed a global anterograde amnesia for verbal material, but he displayed some sparing of nonverbal item recognition relative to nonverbal recall and associative recognition. His performance on an item recognition task that used the remember/know procedure and another that involved repetition of the test phase, to reduce the difference between the familiarity of the targets and foils, suggested that his relatively spared nonverbal item recognition may have been mainly supported by familiarity. This finding is consistent with the view that the anterior temporal lobe, including the perirhinal cortex, can support familiarity-based memory judgments (Brown and Bashir, 2002; Philos Trans R Soc Lond B 357:1083-1095). B.E.'s data also highlight the importance of functional as well as structural scan information for interpreting the pattern of memory deficits shown by patients with selective hippocampal structural lesions.
Cerebral [18F]fluorodeoxyglucose positron emission tomography (18FDG-PET) data from patients suffering amnesia following herpes encephalitis (n=7) or frontal lobe pathology (n=14) were compared with data from age-matched nonamnesic subjects (n=10). All subjects received structural MRI, resting 18FDG-PET scans, and neuropsychological evaluation. PET data were analyzed using complementary statistical parametric mapping and region-of-interest methods. Differential patterns of hypometabolism were found in patients relative to healthy controls. Factor analysis of the neuropsychological data revealed that memory performance was associated with retrosplenial and medial temporal metabolism, and executive function was associated with dorsolateral frontal metabolism. The association between memory performance and retrosplenial metabolism remained statistically significant after accounting for measures of cerebral atrophy using MRI. The significance of the retrosplenium as a major relay station between the thalamus and the medial temporal and frontal lobes--sensitive to changes in either--is discussed in the light of the findings.
It has been proposed that declarative memories can be dependent on both an episodic and a semantic memory system. While the semantic system deals with factual information devoid of reference to its acquisition, the episodic system, characterized by mental time travel, deals with the unique past experience in which an event took place. Episodic memory is characteristically hippocampus-dependent. Place cells are recorded from the hippocampus of rodents and their firing reflects many of the key characteristics of episodic memory. For example, they encode information about "what" happens "where," as well as temporal information. However, when these features are expressed during an animal's behavior, the neuronal activity could merely be categorizing the present situation and could therefore reflect semantic memory rather than episodic memory. We propose that mental time travel is the key feature of episodic memory and that it should take a form, in the awake animal, similar to the replay of behavioral patterns of activity that has been observed in hippocampus during sleep. Using tasks designed to evoke episodic memory, one should be able to see memory reactivation of behaviorally relevant sequences of activity in the awake animal while recording from hippocampus and other cortical structures.
We report a comprehensive investigation of the anterograde memory functions of two patients with memory impairments (RH and JC). RH had neuroradiological evidence of apparently selective right-sided hippocampal damage and an intact cognitive profile apart from selective memory impairments. JC, had neuroradiological evidence of bilateral hippocampal damage following anoxia due to cardiac arrest. He had anomic and "executive" difficulties in addition to a global amnesia, suggesting atrophy extending beyond hippocampal regions. Their performance is compared with that of a previously reported hippocampal amnesic patient who showed preserved recollection and familiarity for faces in the context of severe verbal and topographical memory impairment [VC; Cipolotti, L., Bird, C., Good, T., Macmanus, D., Rudge, P., & Shallice, T. (2006). Recollection and familiarity in dense hippocampal amnesia: A case study. Neuropsychologia, 44, 489-506.] The patients were administered experimental tests using verbal (words) and two types of non-verbal materials (faces and buildings). Receiver operating characteristic analyses were used to estimate the contribution of recollection and familiarity to recognition performance on the experimental tests. RH had preserved verbal recognition memory. Interestingly, her face recognition memory was also spared, whilst topographical recognition memory was impaired. JC was impaired for all types of verbal and non-verbal materials. In both patients, deficits in recollection were invariably associated with deficits in familiarity. JC's data demonstrate the need for a comprehensive cognitive investigation in patients with apparently selective hippocampal damage following anoxia. The data from RH suggest that the right hippocampus is necessary for recollection and familiarity for topographical materials, whilst the left hippocampus is sufficient to underpin these processes for at least some types of verbal materials. Face recognition memory may be adequately subserved by areas outside of the hippocampus.
During the past 100 years clinical studies of amnesia have linked memory impairment to damage of the hippocampus. Yet the damage in these cases has not usually been confined to the hippocampus, and the status of memory functions has often been based on incomplete neuropsychological information. Thus, the human cases have until now left some uncertainty as to whether lesions limited to the hippocampus are sufficient to cause amnesia. Here we report a case of amnesia in a patient (R.B.) who developed memory impairment following an ischemic episode. During the 5 years until his death, R.B. exhibited marked anterograde amnesia, little if any retrograde amnesia, and showed no signs of cognitive impairment other than memory. Thorough histological examination revealed a circumscribed bilateral lesion involving the entire CA1 field of the hippocampus. Minor pathology was found elsewhere in the brain (e.g., left globus pallidus, right postcentral gyrus, left internal capsule), but the only damage that could be reasonably associated with the memory defect was the lesion in the hippocampus. To our knowledge, this is the first reported case of amnesia following a lesion limited to the hippocampus in which extensive neuropsychological and neuropathological analyses have been carried out.
Although neuropsychological studies of the amnesic patient H. M. provide compelling evidence that normal memory function depends on the medial temporal lobe, the full extent of his surgical resection has not been elucidated. We conducted magnetic resonance imaging studies to specify precisely the extent of his bilateral resection and to document any other brain abnormalities. The MRI studies indicated that the lesion was bilaterally symmetrical and included the medial temporal polar cortex, most of the amygdaloid complex, most or all of the entorhinal cortex, and approximately half of the rostrocaudal extent of the intraventricular portion of the hippocampal formation (dentate gyrus, hippocampus, and subicular complex). The collateral sulcus was visible throughout much of the temporal lobe, indicating that portions of the ventral perirhinal cortex, located on the banks of the sulcus, were spared; the parahippocampal cortex (areas TF and TH) was largely intact. The rostrocaudal extent of the ablation was approximately 5.4 cm (left) and 5.1 cm (right). The caudal 2 cm, approximately, of the hippocampus body (normal length, approximately 4 cm) was intact, although atrophic. The temporal stem was intact. Outside the temporal lobes, the cerebellum demonstrated marked atrophy, and the mammillary nuclei were shrunken. The lateral temporal, frontal, parietal, and occipital lobe cortices appeared normal for age 66 years. The mediodorsal thalamic nuclei showed no obvious radiological changes. These findings reinforce the view that lesions of the hippocampal formation and adjacent cortical structures can produce global and enduring amnesia and can exacerbate amnesia beyond that seen after more selective hippocampal lesions.
A case is reported of right temporal lobectomy performed for local epilepsy and resulting in a severe and persisting amnesic state without general dementia. Pre-operative and post-operative electroencephalography, air encephalography, angiography, and clinical examination failed to provide evidence of a cerebral lesion on the unoperated side. Possible explanations of this observation are briefly discussed.RésuméPrésentation d'un cas de lobectomie temporale droite pratiquée pour épilepsie focale, et de l'état amnésique grave et persistant sans démence globale qui en résulta. Les examens pré—et post—opératoires: électroencéphalographie, encéphalographie gazeuse, artériographie et examens cliniques ne fournirent aucune preuve d'une atteinte cérébrale du côté non opéré.Les explications possibles de cette observation sont briévement discutées.ZusammenfassungVorstellung eines Falles einer rechten temporalen Lobectomie, für fokale Epilepsie, bei dem es einen amnesischen Zustand in Folge der Operation gab. Dieser Zustand war schwer und andauernd aber ohne totale Demens. Die Teste (EEG Angiographie, Pheumoencephalographie) die vor une nach der Operation gemacht worden sind beweisen dass die rechte nicht operierte Seite gesund ist.Die möglichen Erklärungen dieses Falles wurden kurz besprochen.
Destructive lesions of the basal forebrain are associated with memory impairment in both humans and experimental animals. The basal forebrain is thought to contribute to memory function by providing cholinergic innervation to critical memory structures such as the hippocampus and amygdala. In previously reported clinical cases of basal forebrain amnesia, multiple neuroanatomical regions have been damaged, preventing identification of the minimal critical lesion necessary to produce an amnestic syndrome. We describe a patient who developed persistent, global anterograde and retrograde amnesia following resection of a low-grade glioma. Post-surgical magnetic resonance imaging studies revealed a small discrete lesion, centred in the right diagonal band of Broca, that included the preoptic area, the anterior hypothalamus, the lamina terminalis and the paraterminal gyrus. The septal nuclei and the cell bodies of the nucleus basalis of Meynert appeared to have been spared, as were other structures in the medial temporal lobe and diencephalon. Our case provides critical support for the independent contribution of the basal forebrain, in particular the diagonal band nuclei, in memory function. We propose that our patient's amnesia resulted from disconnection of pathways between the diagonal band nuclei and the hippocampal region, depriving the hippocampus of cholinergic innervation.
We report a reappraisal of patient NT who became severely amnesic after a right temporal lobectomy for intractable epilepsy (DINSDALE et al., Neuropsychologia 1, 287, 1964 [6]). Histological examination, albeit incomplete, indicated that there was no abnormality in the resected temporal lobe. At autopsy a sclerotic lesion of the unoperated left hippocampal formation was found. This case is therefore not an exception to the general rule that a severe and global amnesic state is only observed with bilateral lesions. Her performance on a wide range of memory tests is shown to be indistinguishable from patients with an amnesic syndrome due to Korsakoff's psychosis.
A patient (E.D.) who had displayed a selective retrograde amnesia in association with transient amnesic episodes (Kapur et al., 1986) was reexamined five years after initial assessment. At the clinical level, his transient amnesic attacks continued, but some of these had clear epileptic features. In addition, EEG investigation indicated temporal lobe abnormality, more prominent in the left temporal region, and supported a clinical diagnosis of temporal lobe epilepsy. Both CT scanning and magnetic resonance imaging were unable to detect the presence of any structural lesion. At the neuropsychological level, there was no evidence of dementia in the form of generalized cognitive dysfunction nor significant deterioration in cognitive functioning since the earlier assessment. Our patient continued to show marked memory loss for public events over the past 20-30 years, in the context of normal or near normal performance on most tests of anterograde memory functioning. While memory for famous scenes and famous faces was markedly impaired, our patient's memory for famous cars was within normal limits and his memory for autobiographical events showed only patchy impairment. Although E.D. performed at an average or above average level on most standard tests of anterograde memory functioning, our patient did show evidence of significant memory loss for public events which had occurred over the past ten years (i.e. since the onset of his illness). The possibility is raised that E.D.'s memory disorder may represent a form of disconnection syndrome.
A patient is reported in whom a classic amnesic syndrome developed as a result of repeated episodes of cerebral ischaemia, accompanied by seizures. The amnesia was very severe for both old and newly acquired memories and the critical lesions defined by MRI were circumscribed areas confined to CA1 and CA2 fields of both hippocampi.
The fact that information acquired before the onset of amnesia can be lost (retrograde amnesia) has fascinated psychologists, biologists, and clinicians for over 100 years. Studies of retrograde amnesia have led to the concept of memory consolidation, whereby medial temporal lobe structures direct the gradual establishment of memory representations in neocortex. Recent theoretical accounts have inspired a simple neural network model that produces behavior consistent with experimental data and makes these ideas about memory consolidation more concrete. Recent physiological and anatomical findings provide important information about how memory consolidation might actually occur.
We report the first human case of combined mammillary body and medial thalamic lesions due to focal pathology. A patient presented with a multi-lobular lesion that affected the mammillary bodies, the medial thalamus and the brain stem. On neuropsychological testing, he showed significant anterograde memory impairment, with marked impairment on delayed story recall, but normal or only mildly impaired performance on retrograde memory tasks. Our findings corroborate the results of recent non-human lesion studies and indicate that some of the well-established features of the amnesic syndrome, such as severe retrograde amnesia, may not be due to primary diencephalic pathology. Significant retrograde amnesia may result from cortical pathology or from an interaction between cortical and subcortical pathology.
I firstly consider general issues relating to our attempts to understand retrograde amnesia. Three main hypotheses are reviewed that have been proposed to account for retrograde amnesia. A theory is outlined to explain the dense autobiographical amnesia that is a focal phenomenon in some cases of severe head injury. This theory postulates that autobiographical retrieval requires the activation of a distributed network of cognitive operations, and that autobiographical amnesia results from the occurrence of multiple areas of pathology, distributed over both space and time.
An extensive battery of tests of anterograde amnesia and remote memory was given to ten amnesics with lesions either to the medial temporal lobes of the diencephalon. These showed that the patients had anterograde amnesia with deficits in verbal and non-verbal recall and recognition, but preservation of word stem completion and intelligence. Mild impairments on executive tests and digit span performance were largely caused by the poor performance of the Korsakoff patients. The amnesics also showed remote memory deficits for personal and public domain information, and temporal gradients were observed for some of the tests. These deficits probably arose because the patients' anterograde amnesia was more severe than their retrograde amnesia even for the recent pre-morbid past. They were more impaired in the recall of details about famous names in their ability to recognize such names. There was also a suggestion that performance on anterograde tests did not relate strongly to that on tests of retrograde amnesia of the remote pre-morbid past. However, this effect was less apparent with memory for personal information when the format and the information tapped were matched on pre- and post-morbid tests.