scholarly journals Episodic memory in semantic dementia: Implications for the roles played by the perirhinal and hippocampal memory systems in new learning

1999 ◽  
Vol 22 (3) ◽  
pp. 452-453
Author(s):  
Kim S. Graham ◽  
John R. Hodges
Keyword(s):  
Recognition Memory ◽  
Episodic Memory ◽  
Perirhinal Cortex ◽  
Memory Systems ◽  
Semantic Dementia ◽  
Long Term Memory ◽  
Term Memory ◽  
Medial Dorsal ◽  
New Learning

Aggleton & Brown (A&B) propose that the hippocampal-anterior thalamic and perirhinal-medial dorsal thalamic systems play independent roles in episodic memory, with the hippocampus supporting recollection-based memory and the perirhinal cortex, recognition memory. In this commentary we discuss whether there is experimental support for the A&B model from studies of long-term memory in semantic dementia.

Two retrievals from a single cue: A bottleneck persists across episodic and semantic memory

2018 ◽  
Vol 72 (5) ◽  
pp. 1005-1028 ◽  
Author(s):  
Franziska Orscheschek ◽  
Tilo Strobach ◽  
Torsten Schubert ◽  
Timothy Rickard
Keyword(s):  
Episodic Memory ◽  
Semantic Memory ◽  
Retrieval Practice ◽  
Memory Systems ◽  
Verbal Response ◽  
Long Term Memory ◽  
Term Memory ◽  
Keypress Response ◽  
Unique Word

There is evidence in the literature that two retrievals from long-term memory cannot occur in parallel. To date, however, that work has explored only the case of two retrievals from newly acquired episodic memory. These studies demonstrated a retrieval bottleneck even after dual-retrieval practice. That retrieval bottleneck may be a global property of long-term memory retrieval, or it may apply only to the case of two retrievals from episodic memory. In the current experiments, we explored whether that apparent dual-retrieval bottleneck applies to the case of one retrieval from episodic memory and one retrieval from highly overlearned semantic memory. Across three experiments, subjects learned to retrieve a left or right keypress response form a set of 14 unique word cues (e.g., black—right keypress). In addition, they learned a verbal response which involved retrieving the antonym of the presented cue (e.g., black—“white”). In the dual-retrieval condition, subjects had to retrieve both the keypress response and the antonym word. The results suggest that the retrieval bottleneck is superordinate to specific long-term memory systems and holds across different memory components. In addition, the results support the assumption of a cue-level response chunking account of learned retrieval parallelism.

scholarly journals Decision-making increases episodic memory via post-encoding consolidation

2018 ◽  
Author(s):  
Vishnu P. Murty ◽  
Sarah DuBrow ◽  
Lila Davachi
Keyword(s):  
Decision Making ◽  
Episodic Memory ◽  
Memory Consolidation ◽  
Functional Neuroimaging ◽  
Perirhinal Cortex ◽  
Long Term Memory ◽  
Mesolimbic System ◽  
Term Memory ◽  
Behavioral Marker

AbstractThe ability for individuals to actively make decisions engages regions within the mesolimbic system and enhances memory for chosen items. In other behavioral contexts, mesolimbic engagement has been shown to enhance episodic memory by supporting consolidation. However, research has yet to investigate how consolidation may support interactions between decision-making and episodic memory. Across two studies, participants encoded items that were occluded by cover screens and could either actively decide which of two items to uncover or were pre-selected by the experimenter. In Study 1, we show that active decision-making reduces forgetting rates across an immediate and 24-hour memory test, a behavioral marker of consolidation. In Study 2, we use functional neuroimaging to characterize putative neural markers of memory consolidation by measuring post-encoding interactions between the hippocampus and perirhinal cortex (PRC). We show that choice-related striatal engagement is associated with increased post-encoding hippocampal-PRC interactions. Finally, we show that a previous reported relationship between choice-related striatal engagement and long-term memory is accounted for by post-encoding hippocampal-PRC interactions. Together these findings support a model by which actively deciding to encode information enhances subsequent consolidation mechanisms to preserve episodic memory for outcomes.

Perception and Recognition Memory in Monkeys Following Lesions of Area TE and Perirhinal Cortex

2000 ◽  
Vol 7 (6) ◽  
pp. 375-382
Author(s):  
Elizabeth A. Buffalo ◽  
Seth J. Ramus ◽  
Larry R. Squire ◽  
Stuart M. Zola
Keyword(s):  
Recognition Memory ◽  
Cortical Area ◽  
Perirhinal Cortex ◽  
Perceptual Processing ◽  
Long Term Memory ◽  
Short Delay ◽  
Term Memory ◽  
Memory Area ◽  
Area Te

Monkeys with lesions of perirhinal cortex (PR group) and monkeys with lesions of inferotemporal cortical area TE (TE group) were tested on a modified version of the delayed nonmatching to sample (DNMS) task that included very short delay intervals (0.5 sec) as well as longer delay intervals (1 min and 10 min). Lesions of the perirhinal cortex and lesions of area TE produced different patterns of impairment. The PR group learned the DNMS task as quickly as normal monkeys (N) when the delay between sample and choice was very short (0.5 sec). However, performance of the PR group, unlike that of the N group, fell to chance levels when the delay between sample and choice was lengthened to 10 min. In contrast to the PR group, the TE group was markedly impaired on the DNMS task even at the 0.5-sec delay, and three of four monkeys with TE lesions failed to acquire the task. The results provide support for the idea that perirhinal cortex is important not for perceptual processing, but for the formation and maintenance of long-term memory. Area TE is important for the perceptual processing of visual stimuli.

scholarly journals Episodic memory: insights from semantic dementia

2001 ◽  
Vol 356 (1413) ◽  
pp. 1423-1434 ◽  
Author(s):  
John R. Hodges ◽  
Kim S. Graham
Keyword(s):  
Episodic Memory ◽  
Semantic Knowledge ◽  
Step Function ◽  
Semantic Dementia ◽  
Learning Performance ◽  
Long Term Memory ◽  
Term Memory ◽  
Source Discrimination ◽  
Memory Processes

Semantic dementia, also known as the temporal lobe variant of fronto– temporal dementia, results in a progressive yet relatively pure loss of semantic knowledge about words, objects and people, and is associated with asymmetric, focal atrophy of the antero–lateral temporal lobes. Semantic dementia provides a unique opportunity to study the organization of long–term memory particularly since initial observations suggested sparing of episodic memory. Recent studies reveal, however, a more complex but theoretically revealing pattern. On tests of autobiographical memory, patients with semantic dementia show a ‘reverse step function’ with sparing of recall of events from the most recent 2 to 5 years but impairment on more distant life periods. Anterograde recognition memory for visual materials is extremely well preserved, except in the most deteriorated cases, although performance is heavily reliant upon perceptual information about the studied stimuli, particularly for items that are no longer known by the subjects. On tests of verbal anterograde memory such as word learning, performance is typically poor even for words which are ‘known’ to the patients. A source discrimination experiment, designed to evaluate familiarity and recollection–based anterograde memory processes, found that patients with semantic dementia showed good item detection, although recollection of source was sometimes impaired. Semantic knowledge about studied items and measures of item detection and source discrimination were largely independent. The implications of these findings for models of long–term memory are discussed. The results support the concept that episodic memory, or at least the recall of temporally specific autobiographical experiences, draws upon a number of separable memory processes, some of which can function independently of semantic knowledge.

scholarly journals Varying demands for cognitive control reveals shared neural processes supporting semantic and episodic memory retrieval

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Deniz Vatansever ◽  
Jonathan Smallwood ◽  
Elizabeth Jefferies
Keyword(s):  
Cognitive Control ◽  
Episodic Memory ◽  
Large Scale ◽  
Inferior Frontal Gyrus ◽  
Memory Systems ◽  
Long Term Memory ◽  
Term Memory ◽  
Neural Processes ◽  
The Impact

AbstractThe categorisation of long-term memory into semantic and episodic systems has been an influential catalyst for research on human memory organisation. However, the impact of variable cognitive control demands on this classical distinction remains to be elucidated. Across two independent experiments, here we directly compare neural processes for the controlled versus automatic retrieval of semantic and episodic memory. In a multi-session functional magnetic resonance imaging experiment, we first identify a common cluster of cortical activity centred on the left inferior frontal gyrus and anterior insular cortex for the retrieval of both weakly-associated semantic and weakly-encoded episodic memory traces. In an independent large-scale individual difference study, we further reveal a common neural circuitry in which reduced functional interaction between the identified cluster and ventromedial prefrontal cortex, a default mode network hub, is linked to better performance across both memory types. Our results provide evidence for shared neural processes supporting the controlled retrieval of information from functionally distinct long-term memory systems.

scholarly journals Decision-making Increases Episodic Memory via Postencoding Consolidation

2019 ◽  
Vol 31 (9) ◽  
pp. 1308-1317 ◽  
Author(s):  
Vishnu P. Murty ◽  
Sarah DuBrow ◽  
Lila Davachi
Keyword(s):  
Decision Making ◽  
Episodic Memory ◽  
Memory Consolidation ◽  
Functional Neuroimaging ◽  
Perirhinal Cortex ◽  
Long Term Memory ◽  
Mesolimbic System ◽  
Term Memory ◽  
Behavioral Marker

The ability for individuals to actively make decisions engages regions within the mesolimbic system and enhances memory for chosen items. In other behavioral contexts, mesolimbic engagement has been shown to enhance episodic memory by supporting consolidation. However, research has yet to investigate how consolidation may support interactions between decision-making and episodic memory. Across two studies, participants encoded items that were covered by occluder screens and could either actively decide which of two items to uncover or an item was preselected by the experimenter. In Study 1, we show that active decision-making reduces forgetting rates across an immediate and 24-hr memory test, a behavioral marker of consolidation. In Study 2, we use functional neuroimaging to characterize putative neural markers of memory consolidation by measuring interactions between the hippocampus and perirhinal cortex (PRC) during a postencoding period that reexposed participants to elements of the decision-making context without exposing them to memoranda. We show that choice-related striatal engagement is associated with increased postencoding hippocampal–PRC interactions. Finally, we show that a previous reported relationship between choice-related striatal engagement and long-term memory is accounted for by these postencoding hippocampal–PRC interactions. Together, these findings support a model by which actively deciding to encode information enhances memory consolidation to preserve episodic memory for outcomes, a process that may be facilitated by reexposure to the original decision-making context.

scholarly journals Induction and knowledge-what

2017 ◽  
Author(s):  
Peter Gärdenfors ◽  
Andreas Stephens
Keyword(s):  
Episodic Memory ◽  
Inductive Reasoning ◽  
Analytic Philosophy ◽  
Memory Systems ◽  
Long Term Memory ◽  
Conceptual Spaces ◽  
New Approach ◽  
Term Memory

Within analytic philosophy, induction has been seen as a problem concerning inferences that have been analysed as relations between sentences. In this article, we argue that induction does not primarily concern relations between sentences, but between properties and categories. We outline a new approach to induction that is based on two theses. The first thesis is epistemological. We submit that there is not only knowledge-how and knowledge-that, but also knowledge-what. Knowledge-what concerns relations between properties and categories and we argue that it cannot be reduced to knowledge-that. We support the partition of knowledge by mapping it onto the long-term memory systems: procedural, semantic and episodic memory. The second thesis is that the role of inductive reasoning is to generate knowledge-what. We use conceptual spaces to model knowledge-what and the relations between properties and categories involved in induction.

scholarly journals A Multivariate Assessment of Age-Related Cognitive Impairment in Octodon degus

2021 ◽  
Vol 15 ◽  
Author(s):  
Daniela S. Rivera ◽  
Carolina B. Lindsay ◽  
Carolina A. Oliva ◽  
Francisco Bozinovic ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Recognition Memory ◽  
Cognitive Performance ◽  
Natural Aging ◽  
Long Term Memory ◽  
Barnes Maze ◽  
Short Term ◽  
Term Memory ◽  
Age Related ◽  
Age Dependent

Aging is a progressive functional decline characterized by a gradual deterioration in physiological function and behavior. The most important age-related change in cognitive function is decline in cognitive performance (i.e., the processing or transformation of information to make decisions that includes speed of processing, working memory, and learning). The purpose of this study is to outline the changes in age-related cognitive performance (i.e., short-term recognition memory and long-term learning and memory) in long-lived Octodon degus. The strong similarity between degus and humans in social, metabolic, biochemical, and cognitive aspects makes it a unique animal model for exploring the mechanisms underlying the behavioral and cognitive deficits related to natural aging. In this study, we examined young adult female degus (12- and 24-months-old) and aged female degus (38-, 56-, and 75-months-old) that were exposed to a battery of cognitive-behavioral tests. Multivariate analyses of data from the Social Interaction test or Novel Object/Local Recognition (to measure short-term recognition memory), and the Barnes maze test (to measure long-term learning and memory) revealed a consistent pattern. Young animals formed a separate group of aged degus for both short- and long-term memories. The association between the first component of the principal component analysis (PCA) from short-term memory with the first component of the PCA from long-term memory showed a significant negative correlation. This suggests age-dependent differences in both memories, with the aged degus having higher values of long-term memory ability but poor short-term recognition memory, whereas in the young degus an opposite pattern was found. Approximately 5% of the young and 80% of the aged degus showed an impaired short-term recognition memory; whereas for long-term memory about 32% of the young degus and 57% of the aged degus showed decreased performance on the Barnes maze test. Throughout this study, we outlined age-dependent cognitive performance decline during natural aging in degus. Moreover, we also demonstrated that the use of a multivariate approach let us explore and visualize complex behavioral variables, and identified specific behavioral patterns that allowed us to make powerful conclusions that will facilitate further the study on the biology of aging. In addition, this study could help predict the onset of the aging process based on behavioral performance.

Dissociative Disorders and Their Clinical Management Part One: Dissociative Amnesia (Including Its Variant Dissociative Fugue)

2018 ◽  
Author(s):  
Angelica Staniloiu ◽  
Hans Markowitsch
Keyword(s):  
Stressful Life Events ◽  
Memory Systems ◽  
Dissociative Disorders ◽  
Long Term Memory ◽  
Term Memory ◽  
Symptom Validity Tests ◽  
Diagnostic And Statistical Manual ◽  
Dissociative Amnesia ◽  
Validity Tests

Dissociative disorders are heterogeneous with respect to clinical features, course, antecedents and treatment. Among them, dissociative amnesia occupies a special place, at times encroaching on the borders between neurology and psychiatry. Herein we describe dissociative amnesia according to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders and outline data on its epidemiology, neurobiology, neuroimaging, clinical and differential diagnosis, neuropsychology, comorbidities, prognosis, treatment and rehabilitation. To enable a neuroscientific approach to its diagnosis, we outline the memory division into short-term and long-term memory, elaborating on the content-based classification of the long-term memory systems. Dissociative amnesia most commonly manifests itself in its retrograde variants (including dissociative fugue), but anterograde variants can also occur. Dissociative amnesia may be overlooked when it occurs on a background of mixed antecedents and comorbidities. Comprehensive neuropsychological assessment – including tests tapping on all memory systems and symptom validity tests – is still insufficiently integrated in the clinical practice, although it could aid in securing an accurate diagnosis, especially in cases with mixed antecedents or concomitant forensic or litigation backgrounds. Presently there is a paucity of treatment and rehabilitation methods for dissociative amnesia. Developing research evidence-based consensus guidelines for diagnosis and treatment is an essential goal. This review contains 6 figures, 7 tables, and 60 references. Key Words : consciousness, episodic-autobiographical memory, mnestic block syndrome, neuroimaging, serial-parallel-independent model, personal identity, stressful life events, malingering, trauma, feigning

scholarly journals Hemispheric Asymmetries in Electroencephalogram Oscillations for Long-Term Memory Retrieval in Healthy Individuals

2020 ◽  
Vol 10 (12) ◽  
pp. 937
Author(s):  
Soyiba Jawed ◽  
Hafeez Ullah Amin ◽  
Aamir Saeed Malik ◽  
Ibrahima Faye
Keyword(s):  
Prefrontal Cortex ◽  
Episodic Memory ◽  
Memory Retrieval ◽  
Frontal Region ◽  
Long Term Memory ◽  
Healthy Individuals ◽  
Term Memory ◽  
Delta Band ◽  
The Right

The hemispherical encoding retrieval asymmetry (HERA) model, established in 1991, suggests that the involvement of the right prefrontal cortex (PFC) in the encoding process is less than that of the left PFC. The HERA model was previously validated for episodic memory in subjects with brain traumas or injuries. In this study, a revised HERA model is used to investigate long-term memory retrieval from newly learned video-based content for healthy individuals using electroencephalography. The model was tested for long-term memory retrieval in two retrieval sessions: (1) recent long-term memory (recorded 30 min after learning) and (2) remote long-term memory (recorded two months after learning). The results show that long-term memory retrieval in healthy individuals for the frontal region (theta and delta band) satisfies the revised HERA asymmetry model.

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