Memory For Public Events Research Articles

Autobiographical significance in past and future public semantic memory: A case-study

Refined investigation of infrequent dissociations within remote memory, such as preservation of autobiographical episodic memory and selective impairment of public semantic memory could provide some insight on the interactions of long-term memory systems and their underlying brain correlates. Combining clinical neuropsychological and neuroimaging methods in the present study, we examined a patient surgically treated for temporal lobe epilepsy showing this rare pattern of dissociation. Specifically, we investigated along the two temporal directions, past and future, his autobiographical episodic memory, semantic memory for public events and famous people and their interaction through the concept of autobiographical significance (AS). The results showed impaired ability not only to recall past but also to imagine future public events in a context of preserved past and future personal episodic memory. Remarkably, impersonal future thinking was impaired regardless of AS, while the autobiographical-significant public past knowledge relied exclusively on the patient's spared autobiographical episodic memory. These results were corroborated by neuroimaging data showing the absence of brain activation for public knowledge devoid of personal significance and activation of the autobiographical memory cerebral network for personally significant public knowledge. Our findings suggest that AS did not ‘restore’ the code to access public semantic memory, but bypassed it by using personal memory sources successful only for past public recollections. Therefore, remembering impersonal and imagining public events seems to require the contribution of public semantic knowledge per se. The patient's cognitive profile suggested a reorganization of memory systems.

Behavioral and neuroanatomical investigation of Highly Superior Autobiographical Memory (HSAM)

A single case study recently documented one woman’s ability to recall accurately vast amounts of autobiographical information, spanning most of her lifetime, without the use of practiced mnemonics (Parker, Cahill, & McGaugh, 2006). The current study reports findings based on eleven participants expressing this same memory ability, now referred to as Highly Superior Autobiographical Memory (HSAM). Participants were identified and subsequently characterized based on screening for memory of public events. They were then tested for personal autobiographical memories as well as for memory assessed by laboratory memory tests. Additionally, whole-brain structural MRI scans were obtained. Results indicated that HSAM participants performed significantly better at recalling public as well as personal autobiographical events as well as the days and dates on which these events occurred. However, their performance was comparable to age- and sex-matched controls on most standard laboratory memory tests. Neuroanatomical results identified nine structures as being morphologically different from those of control participants. The study of HSAM may provide new insights into the neurobiology of autobiographical memory.

Autobiographical memory in amnestic Mild Cognitive Impairment

Autobiographical memory (ABM) was evaluated in 19 patients with amnestic Mild Cognitive Impairment (aMCI) by means of the standardized enquiry developed by Borrini et al. (Psychol Med 19:215-224, 1989). Longitudinal assessments were carried out by re-testing participants at 9-month intervals up to three assessments over 18 months. Although aMCI patients performed significantly worse than age-, gender- and education-matched normal controls, all of them achieved above normal scores according to Italian norms. No evidence of disproportionate sparing of remote memories (i.e., classical temporal gradient, TG) was found. These findings contrast with the previously reported significant impairment of memory for public events (Bizzozero et al. in J Clin Exp Neuropsychol 31:48-56, 2009). Such a discrepancy might be attributed to the adopted ABM enquiry tapping "personal semantics", presumed to rely largely on prefrontal functions, in contrast with the mainly episodic qualification of memory for past public events, which is mostly dependent on hippocampal structures. Our results also support the hypothesis that the contents of remote memory archives may be differentially affected in aMCI.

Impaired event memory and recollection in a case of developmental amnesia

A current debate in the literature is whether all declarative memories and associated memory processes rely on the same neural substrate. Here, we show that H.C., a developmental amnesic person with selective bilateral hippocampal volume loss, has a mild deficit in personal episodic memory, and a more pronounced deficit in public event memory; semantic memory for personal and general knowledge was unimpaired. This was accompanied by a subtle difference in impairment between recollection and familiarity on lab-based tests of recognition memory. Strikingly, H.C.'s recognition did not benefit from a levels-of-processing manipulation. Thus, not all types of declarative memory and related processes can exist independently of the hippocampus even if it is damaged early in life.

Emigration, Generation, and Collective Memories

Research on memory of public events consistently reveals generational effects, where individuals remember best the events from their “critical years” of adolescence and early adulthood—a phenomenon attributed to privileged encoding or retrieval of memories due to primacy of experience. Prior research, however, has not decoupled the youthful period from transitional experiences more generally, raising the question of whether primacy generated by important transitions not tied to youth—such as emigration from one country to another—might also enhance memories. Survey data are used to examine effects of generation on collective memories of public events among a sample of mostly Jewish emigrants from the Soviet Union and its successor states. Evidence points to persistent generational effects, linking memory to adolescence and young adulthood specifically, rather than to primacy of transitional experiences in general. Perspectives that emphasize adolescents’ agentic interpretation, construction of meaning, and decision-making suggest reasons for the link between memories and youth.

Memory for public events in patients with unilateral temporal lobe epilepsy

Memory for public events (PEs) was assessed as a marker of remote declarative memory in 36 patients with temporal lobe epilepsy (TLE) and compared with that of 19 patients with extra-TLE (ETLE), 17 patients with idiopathic generalized epilepsy (IGE), and 23 healthy volunteers. Verbal IQ, inventory-based evidence of depression, handedness, onset of illness, disease duration, and medication were obtained. Memory for PEs was reduced in all patient groups (TLE, P < 0.0001; ETLE, P = 0.009; IGE, P = 0.008). The TLE group showed reduced memory for PEs compared with the other patients with epilepsy ( P = 0.001). A time gradient was observed, with worse memory for PEs of the 1990s and for PEs that occurred after onset of illness. Our data support the key role of the temporal lobe in remote declarative memory. With patients with TLE remembering fewer PEs from the period after onset of epilepsy, the deficits can be partly attributed to unsuccessful consolidation rather than retrieval difficulties alone.

Mild cognitive impairment does entail retrograde amnesia for public events

In this study memory for public events was evaluated in 15 amnesic mild cognitive impairment (aMCI) patients, whose clinical diagnosis was refined through a stringent selection procedure. A total of 9 patients were longitudinally reassessed over an 18-month period. About half of the participants were impaired at baseline and nearly 80% at the end of the 18-month follow-up. Moreover, retrograde memory declined significantly over time. Evidence of a pathological Ribot-type temporal gradient was found in about half of the aMCI patients. This is the first report of a remote memory deficit in aMCI. It highlights amnesia for public events as a frequent accompaniment of this condition. The findings tie in with the hypothesized role of the hippocampal complex in long-term memory.

Reminiscence bump in memory for public events

People tend to recall more personal events from adolescence and early adulthood than from other lifetime periods. Most evidence suggests that differential encoding causes this reminiscence bump. However, the question why personal events are encoded better in those periods is still unanswered. To shed more light on this discussion, we examined memory for public events. Since it is often impossible to ascertain that queried events are equally difficult, we circumvented the issue of equivalence by calculating deviation scores for each trial. We found that participants more frequently answered questions correctly about events that occurred in the period in which they were between 10 and 25 years old. Furthermore, we found that the reminiscence bump was more pronounced for cued recall than for recognition. We argue that these results support the biological account that events are stored better, because the memory system is working more efficiently during adolescence and early adulthood. These results do not falsify the other accounts for differential encoding, because they are not mutually exclusive.

Évaluation des souvenirs des événements publics contemporains dans leur composante sémantique et épisodique dans la maladie de Parkinson

Many patients with Parkinson's disease (PD) have subtle cognitive impairment which often contribute to explain their cognitive complaint. In the literature, neuropsychological studies showed few difficulties for memory and executive functions. We report the performance of 12 PD patients and 12 controls subjects for public events memory. On a 30-item French scale battery (EVE-30), their scores were lower than those of the controls in 4 tasks: evocation, questions, datation and date recognition. They also had difficulties to perform a chronological classification of 8 events. No difference was found between PD patients and control subjects in the events recognition task. Flash bulb memories (FBM) were less frequent in PD patients than in control subjects: 23% versus 34% of cases. A correlation was observed between the scores on the EVE total scale, questions scale, FBM scale and the score on the anterograde recall. Scores on the EVE total scale, questions scale were correlated to the scores on the executive function (initiation) scale. PD patients without dementia seemed to have a low cognitive impairment of retrograde public event memory for episodic and semantic components. Specific difficulties were observed for date evocation and recognition, and chronological classification. These very global deficits to recuperate information can be related to the striatal dopamine depletion which affects the prefrontal functions.

Overgeneral memory for public and autobiographical events in depression and schizophrenia

Introduction. Memory for public and autobiographical events was investigated in people diagnosed with depression, schizophrenia, and a group of healthy controls. The aim was to determine whether the overgeneral memory effect emerged in clinical conditions other than depression and in memory domains other than autobiographical. Methods. 36 participants, 12 in each group, were administered four measures comprising the Hospital Anxiety and Depression Scale, the Autobiographical Memory Test (AMT), the Autobiographical Memory Interview (AMI), and a Public Events Memory Test; the latter developed by the authors and based on the AMT. Results. A pattern of overgeneral autobiographical memory retrieval was found in both clinical groups. A similar pattern in retrieval of public events was also found in people diagnosed with depression and schizophrenia, indicating that overgeneral memory was characteristic of neither clinical condition nor was it associated with a particular memory domain. Conclusions. The findings suggest that overgeneral memory retrieval may represent a fundamental flaw in memory that arises when resources are limited. These findings are discussed in light of current theories of overgeneral memory retrieval.

Évaluation de la mémoire des événements publics : apport de la batterie EVE-30 chez 108 témoins, chez 10 patients MCI et 10 patients Alzheimer

Public events memory is a principal historic component of memory for the past. We propose a new form of the French public events battery EVE which has been elaborated in 1994. EVE-30 uses 30 events dated between 1920 and 2004. Each event assesses recall, recognition, questions and dating. New exposure and flash souvenirs can be explored. One hundred and eight controls aged between 20 and 79 years, ten patients with Alzheimer's disease (AD) and ten patients with amnesic mild cognitive impairment (aMCI) were evaluated. Mean percentage of good responses in controls group is good with a scale of 72p.cent. Performances were gradually observed. Recognition was respectively better than recall, than datation and than questions. Statistical analysis with ANOVA showed that an older age and a higher level of education significantly influenced results (p<0.05). MCI patients and MA patients exhibited more impaired performances than controls. MCI and MA patients had similar impairment in recognition and questions (very altered in the two groups). The French public events battery (EVE 30) can be performed in one hour and may be considered as a neuropsychological tool for the evaluation of memory for the historical past in clinical practice.

Remote Memory in Temporal Lobe Epilepsy

The present study aims at characterizing remote memory in patients with temporal lobe epilepsy (TLE); it also considers the impact of its most important variables (lateralization of the lesion, duration of epilepsy, age at onset, and seizure frequency) on remote memory. We examined the performance of 38 patients with unilateral TLE (19 right TLE and 19 left TLE) and 35 healthy subjects on six remote memory tasks. Memory for personal events was assessed by using the Autobiographical Memory Interview and the Modified Crovitz Test. Memory for public events was evaluated by means of photographs of famous faces and famous scenes, questions about famous events, and the Dead/Alive Test. Both right-TLE and left-TLE groups had impaired memory for autobiographic episodes and public events relative to normal subjects. In contrast, personal semantic memory was preserved. In addition, an effect of laterality was recorded, with right-TLE patients obtaining significantly better scores than left-TLE patients on every test. Duration of epilepsy, age at onset, and seizure frequency did not influence performance on remote memory measures. The comprehensive neuropsychological study of 38 TLE patients showed that this neurologic condition affects remote memory systems differently. We discuss the different factors that could account for this pattern of performance on the bases of both functional brain organization and memory theories.

Déficit sélectif de la mémoire des faits publics associé à un oubli accéléré chez un patient atteint d’épilepsie du lobe temporal gauche

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.

The wane of childhood amnesia for autobiographical and public event memories

We modified Bruce, Dolan, and Phillips-Grant's (2000) threshold procedure for determining the wane of childhood amnesia. In two experiments, undergraduates labelled childhood events (e.g., your first permanent tooth came in) as know or recollect memories and estimated their age at the event's occurrence. In both studies the estimated transition from mostly know memories to mostly recollect memories was roughly 4.7 years. This transition estimate was replicated in a sample of adults (ages 24-65 years) with both Bruce et al.'s event-generation task and the Experiment 1a questionnaire. By contrast, in two experiments a transition estimate of roughly 6 years was found for undergraduates' memories of public events (e.g., the Challenger explosion). The wane of childhood amnesia appears to occur around 4.7 years.

Dissociation dans l’atteinte de la mémoire rétrograde dans un cas d’encéphalite herpétique

Objective: To report an uncommon case of memory impairment after meningoencephalitis. Method: Detailed description of the history, the lesions, the evolution and review of the bibliography. Results: A 33 year-old man showed a loss of verbal anterograde memory and a dissociation of retrograde memory impairment after an herpetic meningo-encephalitis with lesions predominant in the left temporal lobe. The patient had impairment of verbal anterograde memory. Visual memory, procedural one were intact. He had normal performances in frontal tests. Neuropsychological assessment revealed major loss of episodic biographical memory and public events memory, but sparing of semantic biographical memory and professional knowledge. This patient who was amnesic but who had not difficulties with visual memory, procedural memory, frontal abilities and didactic memory conserved ability to work. Conclusion: This case report emphasize the multiplicity of the memory systems and the likely links between episodic biographical memory, semantic biographical memory, autobiographic episodic memory, public event memory and didactic memory.

Too Much Memory

Too Much Memory

Impairment in dating and retrieving remote events in patients with early Parkinson's disease.

Remote memory has been studied in a group of 25 non-demented patients with Parkinson's disease and their performance has been compared with that of 22 healthy control subjects. Only patients...

Remote memory in Parkinson's disease and senile dementia

Remote memory for public events was investigated in 14 demented patients with Parkinson's disease (PD), 14 non-demented PD patients, and 14 controls. These groups were compared with 16 demented patients with dementia that was due to Alzheimer or was of vascular origin (SDAVT), and with a group of elderly controls. The two demented groups were of a different age but displayed a comparable degree of dementia. Remote memory was assessed using a `famous events' questionnaire with items both of comparable salience and difficulty. Results showed severely impaired retrograde memory functions in the two demented groups for both recall and recognition with non-demented PD patients performing similar to the controls. Remote memory impairments extended 30–40 years without any temporal graded memory losses. Non-demented PD patients and controls showed an inferior free recall performance, especially for the remote past. The two PD groups benefited from recognition to the same extent as the controls, whereas the improvement for SDAVT patients was inferior when compared to their elderly controls. In contrast to SDAVT patients, anterograde memory was associated with remote memory for specific decades in demented PD patients. The results are interpreted with respect to an underlying retrieval deficit with a superimposed anterograde impairment common to both types of dementia and an additional loss of storage sites in SDAVT patients. © 1997 Elsevier Science Ltd. All rights reserved.

Dissociation Between Semantic and Autobiographic Memory: A Case Report

We report a patient who showed a dissociation between impaired semantic memory and preserved autobiographic memory. M.N., a 56-year-old right-handed woman, developed a supra sellar meningioma and underwent multiple operations. Following Lineac radiation, necrosis occurred in the left temporal lobe. Magnetic Resonance Imaging revealed bilateral lesions in the temporal lobes and in the right basal frontal lobe. The patient's intellectual deterioration and anterograde amnesia were mild. Language was preserved, but for a subtle anomia. Autobiographic memory remained intact, while semantic memory for public events, historical figures, cultural items, knowledge of low frequency words and technical terms related to her profession was severely impaired. We hypothesize that bilateral lesions of the anterior half of the middle region of the temporal lobe plays a crucial role in causing deficits in semantic memory.

A Study of Recovery of Memory Function in a Case of Witnessed Functional Retrograde Amnesia

We describe a case of transient functional retrograde amnesia that had features of a fugue state, and that was accompanied by loss of personal identity and significant autobiographical amnesia. Uniquely, we were able to gather information from witnesses who observed the episode from its onset, and we were also able to monitor the acute stages of recovery of memory function over the subsequent four-week period. The profile of memory loss was characterised by impaired performance on both autobiographical and public events memory tasks, in the context of normal anterograde memory test scores. Shrinkage of retrograde amnesia took place over a four-week period, with autobiographical and public events components of retrograde memory recovering at the same rate. We discuss the possible role of unconscious processes underlying the episode, as compared to conscious simulation. We argue that most cases of functional retrograde amnesia may represent a combination of conscious simulation and unconscious processes.