scholarly journals Triple Dissociation in the Medial Temporal Lobes: Recollection, Familiarity, and Novelty

2006 ◽  
Vol 96 (4) ◽  
pp. 1902-1911 ◽  
Author(s):  
S. M. Daselaar ◽  
M. S. Fleck ◽  
R. Cabeza
Keyword(s):  
Medial Temporal Lobe ◽  
Memory Performance ◽  
Parahippocampal Gyrus ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Retrieval Processes ◽  
Individual Trial ◽  
Memory Signals ◽  
Magnetic Resonance Imaging Mri ◽  
Left Parietal Cortex

Memory for past events may be based on retrieval accompanied by specific contextual details (recollection) or on the feeling that an item is old (familiarity) or new (novelty) in the absence of contextual details. There are indications that recollection, familiarity, and novelty involve different medial temporal lobe subregions, but available evidence is scarce and inconclusive. Using functional magnetic resonance imaging (MRI), we isolated retrieval-related activity associated with recollection, familiarity, and novelty by distinguishing between linear and nonlinear oldness functions derived from recognition confidence levels. Within the medial temporal lobes (MTLs), we found a triple dissociation among the posterior half of the hippocampus, which was associated with recollection, the posterior parahippocampal gyrus, which was associated with familiarity, and anterior half of the hippocampus and rhinal regions, which were associated with novelty. Furthermore, multiple regression analyses based on individual trial activity showed that all three memory signals, i.e., recollection, familiarity, and novelty, make significant and independent contributions to recognition memory performance. Finally, functional dissociations among recollection, familiarity, and novelty were also found in posterior midline, left parietal cortex, and prefrontal cortex regions. This is the first study to reveal a triple dissociation within the MTL associated with distinct retrieval processes. This finding has direct implications for current memory models.

Structural MRI in Alzheimer’s Disease

2020 ◽  
pp. 208-240
Author(s):  
Briana S. Last ◽  
Batool Rizvi ◽  
Adam M. Brickman
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrovascular Disease ◽  
Cognitive Aging ◽  
Structural Mri ◽  
The Other ◽  
Aging Brain ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Magnetic Resonance Imaging Mri

Structural magnetic resonance imaging (MRI) is a powerful tool to visualize and quantitate morphological and pathological features of the aging brain. Most work that has used structural MRI to study Alzheimer’s disease (AD) focused on the spatial distribution of atrophic changes associated with disease. These studies consistently show focal atrophy beginning in medial temporal lobes in early and presymptomatic stages of AD before spreading globally throughout the cortical mantle. Normal cognitive aging—aging in the absence of major neurodegenerative disease—on the other hand follows and anterior-to-posterior gradient of atrophic change. In addition to atrophic changes, conventional structural MRI can be used to appreciate markers of small and large vessel cerebrovascular disease, including white matter hyperintensities (WMHs), cerebral microbleeds, and infarction. Studies that have examined cerebrovascular changes associated with AD also show a consistent relationship with risk and severity of clinical AD, particularly with regard to lobar microbleeds and posterior WMH. It is unclear whether cerebrovascular changes play an independent role in the clinical expression of AD or whether it is more mechanistically related, reflecting a core feature of the disease. This chapter reviews recent work on regional atrophy in AD and normal aging, as well as work on small and large cerebrovascular disease in AD.

Volumetric MRI Measurements Can Differentiate Alzheimer's Disease, Mild Cognitive Impairment, and Normal Aging

2002 ◽  
Vol 14 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Cássio M. C. Bottino ◽  
Cláudio C. Castro ◽  
Regina L. E. Gomes ◽  
Carlos A. Buchpiguel ◽  
Renato L. Marchetti ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Medial Temporal Lobe ◽  
Function Analysis ◽  
Parahippocampal Gyrus ◽  
Volumetric Mri ◽  
Icd 10 ◽  
Magnetic Resonance Imaging Mri

Background: Volumetric magnetic resonance imaging (MRI) has been extensively studied in the last decade as a method to help with the clinical diagnosis of Alzheimer's disease (AD). In recent years, researchers have also started investigating if that technique would be useful to identify individuals with mild cognitive impairment (MCI), differentiating them from AD patients and from normal elderly controls. This research project was planned to assess the accuracy of volumetric MRI to differentiate those groups of individuals. Method: The investigation involved 39 patients with diagnosis of mild to moderate dementia in AD, according to the criteria of the NINCDS-ADRDA, DSM-III-R, and ICD-10; 21 subjects with complaints of cognitive decline without other psychiatric disorders (MCI); and 20 normal elderly controls. All the subjects were submitted to a standard protocol, including volumetric MRI evaluations. Results: The results indicated that all regions of interest measured (amygdala, hippocampus, and parahippocampal gyrus) were significantly different (p < .005) in AD patients compared to MCI subjects and controls. The left volumetric measures (amygdala, hippocampus, and parahippocampal gyrus) were also significantly different between the MCI subjects and controls (p < .05). The discriminant function analysis correctly classified 88.14% of the AD patients and controls, 81.67% of AD patients and MCI subjects, and 80.49% of the MCI subjects and controls. Conclusions: The results suggest that measures of medial temporal lobe regions are useful to identify mild to moderate AD patients and MCI subjects, separating them from normal elderly individuals.

scholarly journals Hippocampal Volume Influences The Correlations Between White Matter Disruption and Tau Protein in aMCI and mild AD

2020 ◽  
Author(s):  
Thamires Naela Cardoso Magalhães ◽  
Raphael Fernandes Casseb ◽  
Christian Luiz Baptista Gerbelli ◽  
Luciana Ramalho Pimentel-Silva ◽  
Mateus Henrique Nogueira ◽  
...  
Keyword(s):  
White Matter ◽  
Medial Temporal Lobe ◽  
Hippocampal Volume ◽  
Tau Proteins ◽  
Cortical Atrophy ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Prodromal Ad ◽  
Transentorhinal Cortex

Abstract Background: Alzheimer’s disease (AD) is classically considered a grey matter (GM) disease that starts in the transentorhinal cortex and spreads to limbic and neocortical regions. However, white matter (WM) damage could be more severe and widespread than expected cortical atrophy. The role of AD biomarkers and WM integrity throughout the brain is unclear, especially in amnestic Mild Cognitive Impairment (aMCI) patients, a possible prodromal AD dementia stage. If WM damage can be detected even before the development of cortical atrophy and overt dementia and in the AD process, Aβ42 Tau (and its phosphorylated form) could directly affect WM. Methods: We analyzed in this study 183 individuals - 48 aMCI in the AD continuum (altered CSF Aβ42), 30 patients with very mild or mild AD dementia and 105 normal controls. All subjects underwent neuropsychological evaluation and MRI exams. aMCI and mild AD individuals were also submitted to CSF puncture to evaluate AD biomarkers.Results: We observed several significant differences in WM integrity regarding the DTI measures between individuals and we found significant correlations between fornix and right cingulum hippocampal tracts and Tau and p-Tau proteins. Conclusions: We hypothesize that significant correlations with tracts anatomically far from more well-established GM atrophic regions, like medial temporal lobes, would support a more direct effect of pathological proteins on WM, whereas medial temporal lobe (MTL) correlations would favor WD and/or a direct spreading of pathology from the hippocampus.

Does the Medial Temporal Lobe Bind Phonological Memories?

2001 ◽  
Vol 13 (5) ◽  
pp. 593-609 ◽  
Author(s):  
Raymond Knott ◽  
William Marslen-Wilson
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Lexical Representation ◽  
Phonological Memory ◽  
Distinctive Pattern ◽  
Medial Temporal Lobes ◽  
Phonological Representations ◽  
Temporal Lobes ◽  
Phonological Errors

The medial temporal lobes play a central role in the consolidation of new memories. Medial temporal lesions impair episodic learning in amnesia, and disrupt vocabulary acquisition. To investigate the role of consolidation processes in phonological memory and to understand where and how, in amnesia, these processes begin to fail, we reexamined phonological memory in the amnesic patient HM. While HM's word span performance was normal, his supraspan recall was shown to be markedly impaired, with his recall characterized by a distinctive pattern of phonological errors, where he recombined phonemes from the original list to form new response words. These were similar to errors observed earlier for patients with specifically semantic deficits. Amnesic Korsakoff's patients showed a similar, though much less marked, pattern. We interpret the data in terms of a model of lexical representation where temporal lobe damage disrupts the processes that normally bind semantic and phonological representations.

scholarly journals Delay-dependent contributions of medial temporal lobe regions to episodic memory retrieval

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Maureen Ritchey ◽  
Maria E Montchal ◽  
Andrew P Yonelinas ◽  
Charan Ranganath
Keyword(s):  
Episodic Memory ◽  
Medial Temporal Lobe ◽  
Functional Neuroimaging ◽  
Contextual Information ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Pattern Similarity ◽  
Delayed Recognition ◽  
Delay Dependent ◽  
Over Time

The medial temporal lobes play an important role in episodic memory, but over time, hippocampal contributions to retrieval may be diminished. However, it is unclear whether such changes are related to the ability to retrieve contextual information, and whether they are common across all medial temporal regions. Here, we used functional neuroimaging to compare neural responses during immediate and delayed recognition. Results showed that recollection-related activity in the posterior hippocampus declined after a 1-day delay. In contrast, activity was relatively stable in the anterior hippocampus and in neocortical areas. Multi-voxel pattern similarity analyses also revealed that anterior hippocampal patterns contained information about context during item recognition, and after a delay, context coding in this region was related to successful retention of context information. Together, these findings suggest that the anterior and posterior hippocampus have different contributions to memory over time and that neurobiological models of memory must account for these differences.

Visual Working Memory Is Impaired when the Medial Temporal Lobe Is Damaged

2006 ◽  
Vol 18 (7) ◽  
pp. 1087-1097 ◽  
Author(s):  
Ingrid R. Olson ◽  
Katherine Sledge Moore ◽  
Marianna Stark ◽  
Anjan Chatterjee
Keyword(s):  
Working Memory ◽  
Medial Temporal Lobe ◽  
Memory Load ◽  
Short Term ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Impaired Memory ◽  
Rehearsal Strategies ◽  
Verbal Component

The canonical description of the role of the medial temporal lobes (MTLs) in memory is that short-term forms of memory (e.g., working memory [WM]) are spared when the MTL is damaged, but longer term forms of memory are impaired. Tests used to assess this have typically had a heavy verbal component, potentially allowing explicit rehearsal strategies to maintain the WM trace over the memory delay period. Here we test the hypothesis that the MTL is necessary for visual WM when verbal rehearsal strategies are difficult to implement. In three patients with MTL damage we found impairments in spatial, face, and color WM, at delays as short as 4 sec. Impaired memory could not be attributed to memory load or perceptual problems. These findings suggest that the MTLs are critical for accurate visual WM.

scholarly journals Hippocampal Volume Influences the Correlations Between White Matter Disruption and Tau Protein in aMCI and mild AD

2020 ◽  
Author(s):  
Thamires Naela Cardoso Magalhães ◽  
Raphael Fernandes Casseb ◽  
Christian Luiz Baptista Gerbelli ◽  
Mateus Henrique Nogueira ◽  
Luciana Ramalho Pimentel-Silva ◽  
...  
Keyword(s):  
Medial Temporal Lobe ◽  
Hippocampal Volume ◽  
Cortical Atrophy ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Prodromal Ad ◽  
Transentorhinal Cortex ◽  
The Brain ◽  
Normal Controls

Abstract BackgroundAlzheimer’s disease (AD) is classically considered a grey matter (GM) disease that starts in transentorhinal cortex and spread to limbic and neocortical regions. However, withe matter (WM) damage could be more severe and widespread than expected cortical atrophy. It is not clear the role of AD biomarkers and WM integrity throughout the brain, especially including amnestic Mild Cognitive Impairment (aMCI) patients, a possible prodromal AD dementia stage, if WM damage can be detected even before the development of cortical atrophy and overt dementia and in AD process, Aβ42 Tau (and its phosphorylated form) could directly affect WM.MethodsWe analyzed in this study 183 individuals - 48 aMCI in the AD continuum (altered CSF Aβ42), 30 patients with very mild or mild AD dementia and 105 normal controls. All subjects underwent neuropsychological evaluation and MRI exam. aMCI and mild AD individuals were also submitted to CSF puncture to evaluate AD biomarkers.ResultsWe observed several significant differences in WM integrity regarding the DTI measures between individuals and we found significant correlations between fornix and right cingulum hippocampal tracts and Tau and p-Tau proteins.ConclusionsWe hypothesize that significant correlations with tracts anatomically far from more well-established GM atrophic regions, like medial temporal lobes, would support a more direct effect of pathological proteins on WM, whereas medial temporal lobe (MTL) correlations would favor WD and/or a direct spreading of pathology from hippocampus.

scholarly journals Toward a Psychophysiology of Expertise

2006 ◽  
Vol 20 (4) ◽  
pp. 253-258 ◽  
Author(s):  
Ognjen Amidzic ◽  
Hartmut J. Riehle ◽  
Thomas Elbert
Keyword(s):  
Medial Temporal Lobe ◽  
Hippocampal Formation ◽  
Time Dependent ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Active Memory ◽  
Gamma Band Activity ◽  
Chess Players ◽  
The Relationship ◽  
Band Activity

Gamma-band activity (GBA) bursts have been viewed as a signature for ignitions in localized Hebbian cell assemblies and are thought to indicate active memory. Using whole-head magnetoencephalography, we recorded focal bursts of GBA during chess playing. Unlike highly skilled chess grandmasters, with amateur chess players focal gamma bursts prevailed in deeper structures in the region of the medial temporal lobes. This observation is consistent with the interpretation of memory formation in amateur chess players. For the frontal and parietal cortex the relationship was reversed, with more frequent gamma bursts found in chess grandmasters, indicating that the retrieval of chunks from expert memory is based on the recruitment of these neocortical areas. The results suggest the possibility that time-dependent reorganization during the formation of expert memory can be studied in humans and support the theory that the medial temporal lobe and hippocampal formation play a transitional role during the creation of expert memory in the neocortex.

The von Restorff Effect in Amnesia: The Contribution of the Hippocampal System to Novelty-Related Memory Enhancements

2004 ◽  
Vol 16 (1) ◽  
pp. 15-23 ◽  
Author(s):  
M. M. Kishiyama ◽  
A. P. Yonelinas ◽  
M. M. Lazzara
Keyword(s):  
Medial Temporal Lobe ◽  
Critical Role ◽  
Hippocampal Damage ◽  
Medial Temporal Lobes ◽  
Brain Areas ◽  
Temporal Lobes ◽  
Control Subjects ◽  
Healthy Control ◽  
Thalamic Lesions ◽  
Better Than

The ability to detect novelty is a characteristic of all mammalian nervous systems (Sokolov, 1963), and it plays a critical role in memory in the sense that items that are novel, or distinctive, are remembered better than those that are less distinct (von Restorff, 1933). Although several brain areas are sensitive to stimulus novelty, it is not yet known which regions play a role in producing novelty-related effects on memory. In the current study, we investigated novelty effects on recognition memory in amnesic patients and healthy control subjects. The control subjects demonstrated better recognition for items that were novel (i.e., presented in an infrequent color), and this effect was found for both recollection and familiarity-based responses. However, the novelty advantage was effectively eliminated in patients with extensive medial temporal lobe damage, mild hypoxic patients expected to have relatively selective hippocampal damage, and in a patient with thalamic lesions. The results indicate that the human medial temporal lobes play a critical role in producing normal novelty effects in memory.

scholarly journals Theories of episodic memory

2001 ◽  
Vol 356 (1413) ◽  
pp. 1395-1408 ◽  
Author(s):  
Andrew R. Mayes ◽  
Neil Roberts
Keyword(s):  
Episodic Memory ◽  
Medial Temporal Lobe ◽  
Functional Neuroimaging ◽  
Memory Storage ◽  
Visual Object ◽  
Medial Temporal Lobes ◽  
Temporal Lobes ◽  
Episodic Information ◽  
Encoding And Retrieval

Theories of episodic memory need to specify the encoding (representing), storage, and retrieval processes that underlie this form of memory and indicate the brain regions that mediate these processes and how they do so. Representation and re–representation (retrieval) of the spatiotemporally linked series of scenes, which constitute an episode, are probably mediated primarily by those parts of the posterior neocortex that process perceptual and semantic information. However, some role of the frontal neocortex and medial temporal lobes in representing aspects of context and high–level visual object information at encoding and retrieval cannot currently be excluded. Nevertheless, it is widely believed that the frontal neocortex is mainly involved in coordinating episodic encoding and retrieval and that the medial temporal lobes store aspects of episodic information. Establishing where storage is located is very difficult and disagreement remains about the role of the posterior neocortex in episodic memory storage. One view is that this region stores all aspects of episodic memory ab initio for as long as memory lasts. This is compatible with evidence that the amygdala, basal forebrain, and midbrain modulate neocortical storage. Another view is that the posterior neocortex only gradually develops the ability to store some aspects of episodic information as a function of rehearsal over time and that this information is initially stored by the medial temporal lobes. A third view is that the posterior neocortex never stores these aspects of episodic information because the medial temporal lobes store them for as long as memory lasts in an increasingly redundant fashion. The last two views both postulate that the medial temporal lobes initially store contextual markers that serve to cohere featural information stored in the neocortex. Lesion and functional neuroimaging evidence still does not clearly distinguish between these views. Whether the feeling that an episodic memory is familiar depends on retrieving an association between a retrieved episode and this feeling, or by an attribution triggered by a priming process, is unclear. Evidence about whether the hippocampus and medial temporal lobe cortices play different roles in episodic memory is conflicting. Identifying similarities and differences between episodic memory and both semantic memory and priming will require careful componential analysis of episodic memory.

Sign in / Sign up

Export Citation Format

Share Document