scholarly journals The convergence and divergence of episodic and semantic functions across lateral parietal cortex

2020 ◽  
Author(s):  
Gina F. Humphreys ◽  
JeYoung Jung ◽  
Matthew A. Lambon Ralph
Keyword(s):  
White Matter ◽  
Semantic Memory ◽  
Parietal Cortex ◽  
Memory Retrieval ◽  
Task Difficulty ◽  
Structural Connectivity ◽  
Angular Gyrus ◽  
Episodic Retrieval ◽  
Semantic Retrieval ◽  
White Matter Connectivity

AbstractSeveral decades of neuropsychological and neuroimaging research have highlighted the importance of lateral parietal cortex (LPC) across a myriad of cognitive domains. Yet, despite the prominence of this region the underlying function of LPC remains unclear. Two domains that have placed particular emphasis on LPC involvement are semantic memory and episodic memory retrieval. From each domain, sophisticated models have been proposed as to the underlying function, as well as the more domain-general that LPC is engaged by any form of internally-directed cognition (episodic and semantic retrieval both being examples if this process). Here we directly address these alternatives using a combination of fMRI and DTI white-matter connectivity data. The results show that ventral LPC (angular gyrus) was positively engaged during episodic retrieval but disengaged during semantic memory retrieval. In addition, the level of activity negatively varied with task difficulty in the semantic task whereas episodic activation was independent of difficulty. In contrast, dorsal LPC (intraparietal sulcus) showed domain general activation that was positively correlated with task difficulty. In terms of structural connectivity, a dorsal-ventral and anterior-posterior gradient of connectivity was found to different processing networks (e.g., mid-angular gyrus (AG) connected with episodic retrieval). We propose a unifying model in which LPC as a whole might share a common underlying function (e.g., multimodal buffering) and variations across subregions arise due to differences in the underlying white matter connectivity.

Frontal Brain Activity during Episodic and Semantic Retrieval: Insights from Event-Related Potentials

1999 ◽  
Vol 11 (6) ◽  
pp. 598-609 ◽  
Author(s):  
Charan Ranganath ◽  
Ken A. Paller
Keyword(s):  
Prefrontal Cortex ◽  
Memory Retrieval ◽  
Brain Activity ◽  
Novelty Detection ◽  
Event Related Potentials ◽  
Episodic Retrieval ◽  
Semantic Retrieval ◽  
Retrieval Task ◽  
Related Potentials ◽  
The Right

Previous neuropsychological and neuroimaging results have implicated the prefrontal cortex in memory retrieval, although its precise role is unclear. In the present study, we examined patterns of brain electrical activity during retrieval of episodic and semantic memories. In the episodic retrieval task, participants retrieved autobiographical memories in response to event cues. In the semantic retrieval task, participants generated exemplars in response to category cues. Novel sounds presented intermittently during memory retrieval elicited a series of brain potentials including one identifiable as the P3a potential. Based on prior research linking P3a with novelty detection and with the frontal lobes, we predicted that P3a would be reduced to the extent that novelty detection and memory retrieval interfere with each other. Results during episodic and semantic retrieval tasks were compared to results during a task in which subjects attended to the auditory stimuli. P3a amplitudes were reduced during episodic retrieval, particularly at right lateral frontal scalp locations. A similar but less lateralized pattern of frontal P3a reduction was observed during semantic retrieval. These findings support the notion that the right prefrontal cortex is engaged in the service of memory retrieval, particularly for episodic memories.

scholarly journals Effects of Alzheimer’s and Vascular Pathologies on Structural Connectivity in Early- and Late-Onset Alzheimer’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Wha Jin Lee ◽  
Cindy W. Yoon ◽  
Sung-Woo Kim ◽  
Hye Jin Jeong ◽  
Seongho Seo ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
White Matter ◽  
Magnetic Resonance ◽  
White Matter Hyperintensities ◽  
Late Onset ◽  
Structural Connectivity ◽  
Resonance Imaging ◽  
White Matter Connectivity

Early- and late-onset Alzheimer’s disease (AD) patients often exhibit distinct features. We sought to compare overall white matter connectivity and evaluate the pathological factors (amyloid, tau, and vascular pathologies) that affect the disruption of connectivity in these two groups. A total of 50 early- and 38 late-onset AD patients, as well as age-matched cognitively normal participants, were enrolled and underwent diffusion-weighted magnetic resonance imaging to construct fractional anisotropy-weighted white matter connectivity maps. [18F]-THK5351 PET, [18F]-Flutemetamol PET, and magnetic resonance imaging were used for the evaluation of tau and related astrogliosis, amyloid, and small vessel disease markers (lacunes and white matter hyperintensities). Cluster-based statistics was performed for connectivity comparisons and correlation analysis between connectivity disruption and the pathological markers. Both patient groups exhibited significantly disrupted connectivity compared to their control counterparts with distinct patterns. Only THK retention was related to connectivity disruption in early-onset AD patients, and this disruption showed correlations with most cognitive scores, while late-onset AD patients had disrupted connectivity correlated with amyloid deposition, white matter hyperintensities, and lacunes in which only a few cognitive scores showed associations. These findings suggest that the pathogenesis of connectivity disruption and its effects on cognition are distinct between EOAD and LOAD.

scholarly journals A Unifying Account of Angular Gyrus Contributions to Episodic and Semantic Cognition

2020 ◽  
Author(s):  
Gina Humphreys ◽  
Matt Lambon Ralph ◽  
Jon Simons
Keyword(s):  
Semantic Memory ◽  
Parietal Cortex ◽  
Cognitive Task ◽  
Angular Gyrus ◽  
Domain Specific ◽  
Semantic Cognition ◽  
Model Based ◽  
Cognitive Activities

The angular gyrus (AG) region of lateral parietal cortex has been implicated in a wide variety of tasks and functions, generating numerous influential theories. However, these theories fail to explain why so many apparently distinct cognitive activities implicate common parietal structures. We propose a unifying model, based on a set of central principles, to account for coalescences of cognitive task activations across AG. To illustrate, we show how these principles account for findings from studies of episodic and semantic memory that have independently implicated the same AG regions but thus far been considered from largely domain-specific perspectives. We conclude that AG computations, as part of a wider lateral parietal system, enable the online dynamic buffering of multi-sensory spatio-temporally extended representations.

scholarly journals Tau Deposition and Structural Connectivity Demonstrate Differential Association Patterns with Neurocognitive Tests

2021 ◽  
Author(s):  
Zack Hall ◽  
Billy Chien ◽  
Yi Zhao ◽  
Shannon L. Risacher ◽  
Andrew J. Saykin ◽  
...  
Keyword(s):  
White Matter ◽  
Interaction Analysis ◽  
Memory Function ◽  
Structural Connectivity ◽  
Neurocognitive Performance ◽  
Association Patterns ◽  
Neurocognitive Tests ◽  
White Matter Connectivity ◽  
Network Metrics

Abstract Tau neurofibrillary tangles have a central role in the pathogenesis of Alzheimer’s Disease (AD). Mounting evidence indicates that the propagation of tau is assisted by brain connectivity with weakened white-matter integrity along the propagation pathways. Recent advances in tau positron emission tomography tracers and diffusion magnetic resonance imaging allow the visualization of tau pathology and white-matter connectivity of the brain in vivo. The current study aims to investigate how tau deposition and structural connectivity are associated with memory function in prodromal AD. In this study, tau accumulation and structural connectivity data from 83 individuals (57 cognitively normal participants and 26 participants with mild cognitive impairment) were associated with neurocognitive test scores. Statistical analyses were performed in 70 cortical/subcortical brain regions to determine: 1. the level of association between tau and network metrics extracted from structural connectivity and 2. the association patterns of brain memory function with tau accumulation and network metrics. The results showed that tau accumulation and network metrics were correlated in early tau deposition regions. Furthermore, tau accumulation was associated with worse performance in almost all neurocognitive tests performance evaluated in the study. In comparison, decreased network connectivity was associated with declines in the delayed memory recall in Craft Stories and Benson Figure Copy. Interaction analysis indicates that tau deposition and dysconnectivity have a synergistic effect on the delayed Benson Figure Recall. Overall, our findings indicate that both tau deposition and structural dysconnectivity are associated with neurocognitive dysfunction. They also suggest that tau-PET may have better sensitivity to neurocognitive performance than diffusion MRI-derived measures of white-matter connectivity

Effects of music listening on creative cognition and semantic memory retrieval

2018 ◽  
Vol 48 (4) ◽  
pp. 513-528 ◽  
Author(s):  
Katherine E. Eskine ◽  
Ashanti E. Anderson ◽  
Madeline Sullivan ◽  
Edward J. Golob
Keyword(s):  
Semantic Memory ◽  
Memory Retrieval ◽  
Classical Music ◽  
Alternative Hypothesis ◽  
Semantic Knowledge ◽  
Music Listening ◽  
Semantic Retrieval ◽  
Creative Cognition ◽  
Positive Effects ◽  
The Relationship

Listening to music can affect cognitive abilities and may impact creative cognition. This effect is believed to be caused by music’s impact on arousal and mood. However, this causal relationship has been understudied. Furthermore, the strength of semantic knowledge associations has also been linked to creativity and provides an alternative hypothesis for increases in creative cognition. The relationship between music, mood, semantic knowledge, and creative cognition is not well understood. The present study consisted of two experiments. The first examined the relationship between music listening and creative cognition, the second additionally sought to examine whether the effect of music on semantic memory and/or mood are mechanisms that promote creative cognition. In the first experiment, participants completed 15 items of the Remote Associates Test of Creativity after listening to hip-hop music, classical music, and babble. In addition to replicating the first experiment, the second also measured mood and semantic memory. In both experiments participants displayed greater creativity after listening to music. Semantic memory retrieval was enhanced after listening to music, but creative cognition and semantic memory were not significantly correlated with mood. The findings show parallel, positive effects on creative cognition, semantic retrieval, and mood when subjects listen to music.

scholarly journals Tau deposition and structural connectivity demonstrate differential association patterns with neurocognitive tests

2021 ◽  
Author(s):  
Zack Hall ◽  
Billy Chien ◽  
Yi Zhao ◽  
Shannon L. Risacher ◽  
Andrew J. Saykin ◽  
...  
Keyword(s):  
White Matter ◽  
Interaction Analysis ◽  
Memory Function ◽  
Structural Connectivity ◽  
Neurocognitive Performance ◽  
Association Patterns ◽  
Neurocognitive Tests ◽  
White Matter Connectivity ◽  
Network Metrics

AbstractTau neurofibrillary tangles have a central role in the pathogenesis of Alzheimer’s Disease (AD). Mounting evidence indicates that the propagation of tau is assisted by brain connectivity with weakened white-matter integrity along the propagation pathways. Recent advances in tau positron emission tomography tracers and diffusion magnetic resonance imaging allow the visualization of tau pathology and white-matter connectivity of the brain in vivo. The current study aims to investigate how tau deposition and structural connectivity are associated with memory function in prodromal AD. In this study, tau accumulation and structural connectivity data from 83 individuals (57 cognitively normal participants and 26 participants with mild cognitive impairment) were associated with neurocognitive test scores. Statistical analyses were performed in 70 cortical/subcortical brain regions to determine: 1. the level of association between tau and network metrics extracted from structural connectivity and 2. the association patterns of brain memory function with tau accumulation and network metrics. The results showed that tau accumulation and network metrics were correlated in early tau deposition regions. Furthermore, tau accumulation was associated with worse performance in almost all neurocognitive tests performance evaluated in the study. In comparison, decreased network connectivity was associated with declines in the delayed memory recall in Craft Stories and Benson Figure Copy. Interaction analysis indicates that tau deposition and dysconnectivity have a synergistic effect on the delayed Benson Figure Recall. Overall, our findings indicate that both tau deposition and structural dysconnectivity are associated with neurocognitive dysfunction. They also suggest that tau-PET may have better sensitivity to neurocognitive performance than diffusion MRI-derived measures of white-matter connectivity.

scholarly journals Distinct generation of subjective vividness and confidence during naturalistic memory retrieval in the angular gyrus

2021 ◽  
Author(s):  
Futing Zou ◽  
Sze Chai Kwok
Keyword(s):  
Resting State ◽  
Memory Retrieval ◽  
Subjective Experience ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Angular Gyrus ◽  
Episodic Retrieval ◽  
Resting State Functional Connectivity ◽  
Mediating Role ◽  
Control Stimulation

Abstract Subjective experience of remembering is a hallmark of episodic memory, which is deemed crucial for effective behavior. A fundamental and enduring puzzle is the origin of confidence in memory; for example, does the confidence during episodic retrieval depend upon the subjective sensed vividness? The angular gyrus (AnG) exhibits a sensitivity to the subjective experience of remembering, but its direct contribution to the monitoring of subjective mnemonic experience has hitherto been lacking. Here, using a naturalistic video-watching paradigm combined with repetitive transcranial magnetic stimulation (rTMS) and resting-state functional magnetic resonance imaging, we found that pre-retrieval rTMS targeting the left AnG selectively alters the vividness efficiency compared to control stimulation while keeping metacognitive efficiency and objective memory accuracy unaffected. Using trial-wise data, we showed that AnG stimulation altered the mediating role of vividness in confidence in the accuracy of memory judgment. Furthermore, resting-state functional connectivity of hippocampus and AnG was specifically associated with vividness efficiency, while the connectivity of hippocampus and medial prefrontal cortex was associated with metacognitive efficiency across individuals. These findings identify the causal involvement of AnG in gauging the vividness, but not the confidence, of memory, thereby providing evidence for a differentiation account of conscious assessment of memory retrieval.

scholarly journals Left angular gyrus disconnection impairs multiplication fact retrieval

2021 ◽  
Author(s):  
Stefan Smaczny ◽  
Christoph Sperber ◽  
Stefanie Jung ◽  
Korbinian Moeller ◽  
Hans-Otto Karnath ◽  
...  
Keyword(s):  
White Matter ◽  
Superior Temporal Gyrus ◽  
Angular Gyrus ◽  
Subcortical Structures ◽  
Arithmetic Fact ◽  
White Matter Tractography ◽  
White Matter Connectivity ◽  
Left Angular Gyrus ◽  
Fact Retrieval ◽  
Arithmetic Fact Retrieval

Arithmetic fact retrieval has been suggested to recruit a left-lateralized network comprising perisylvian language areas, parietal areas such as the angular gyrus (AG), and subcortical structures such as the hippocampus. However, the underlying white matter connectivity of these areas has not been evaluated systematically so far. Using simple multiplication problems, we evaluated how disconnections in parietal brain areas affected arithmetic fact retrieval following stroke. We derived disconnectivity measures by jointly considering data from n=73 patients with acute unilateral lesions in either hemisphere and a white-matter tractography atlas (HCP-842) using the Lesion Quantification Toolbox (LQT). Whole-brain voxel-based analysis indicated a left-hemispheric cluster of white matter fibers connecting the AG and superior temporal areas to be associated with a fact retrieval deficit. Subsequent analyses of direct grey-to-grey matter disconnections revealed that disconnections of additional left-hemispheric areas (e.g., between the superior temporal gyrus and parietal areas) were significantly associated with the observed fact retrieval deficit. Results imply that disconnections of parietal areas (i.e., the AG) with language-related areas (i.e., superior and middle temporal gyri) seem specifically detrimental to arithmetic fact retrieval. This suggests that arithmetic fact retrieval recruits a widespread left-hemispheric network and emphasizes the relevance of white matter connectivity for number processing.

scholarly journals Distinct generation of subjective vividness and confidence during naturalistic memory retrieval in angular gyrus

2021 ◽  
Author(s):  
Futing Zou ◽  
Sze Chai Kwok
Keyword(s):  
Resting State ◽  
Memory Retrieval ◽  
Subjective Experience ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Angular Gyrus ◽  
Episodic Retrieval ◽  
Functional Magnetic Resonance ◽  
Resting State Functional Connectivity ◽  
Memory Accuracy ◽  
Control Stimulation

AbstractSubjective experience of remembering is a hallmark of episodic memory, which enables us to monitor experiences, identify mistakes, and adjust our decisions accordingly. A fundamental and enduring puzzle is the origin of confidence in memory; for example, does the confidence during episodic retrieval depend upon the subjective sensed vividness, or does confidence and vividness reflect dissociable introspective processes? The angular gyrus (AnG) exhibits a sensitivity to subjective experience of remembering, but its direct contribution to the monitoring of internal subjective mnemonic experience has hitherto been lacking. Here we combined a novel naturalistic video-watching paradigm with repetitive transcranial magnetic stimulation (rTMS) and resting-state functional magnetic resonance imaging (fMRI) to test the idea that vividness and confidence are generated differently during retrieval. We found that pre-retrieval rTMS targeting the left AnG selectively alters the vividness efficiency compared to control stimulation while keeping metacognitive efficiency and objective memory accuracy unaffected. Using trial-wise data, we showed that vividness mediates the association between confidence and objective memory accuracy and such mediation was eradicated by AnG stimulation. Furthermore, resting-state functional connectivity of hippocampus and AnG was specifically associated with vividness efficiency, while the connectivity of hippocampus and medial prefrontal cortex was associated with metacognitive efficiency across individuals. These findings identify a role for the AnG in gauging the vividness, but not the confidence, of memory, thereby providing evidence for a differentiation account of conscious assessment of memory by functionally and anatomically dissociating the monitoring of vividness from confidence.

scholarly journals Common and Unique Neural Activations in Autobiographical, Episodic, and Semantic Retrieval

2007 ◽  
Vol 19 (9) ◽  
pp. 1520-1534 ◽  
Author(s):  
Hana Burianova ◽  
Cheryl L. Grady
Keyword(s):  
Semantic Memory ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Declarative Memory ◽  
Inferior Frontal Gyrus ◽  
Imaging Study ◽  
Neural Correlates ◽  
Semantic Retrieval ◽  
Lingual Gyrus ◽  
Conscious Recollection

This study sought to explore the neural correlates that underlie autobiographical, episodic, and semantic memory. Autobiographical memory was defined as the conscious recollection of personally relevant events, episodic memory as the recall of stimuli presented in the laboratory, and semantic memory as the retrieval of factual information and general knowledge about the world. Our objective was to delineate common neural activations, reflecting a functional overlap, and unique neural activations, reflecting functional dissociation of these memory processes. We conducted an event-related functional magnetic resonance imaging study in which we utilized the same pictorial stimuli but manipulated retrieval demands to extract autobiographical, episodic, or semantic memories. The results show a functional overlap of the three types of memory retrieval in the inferior frontal gyrus, the middle frontal gyrus, the caudate nucleus, the thalamus, and the lingual gyrus. All memory conditions yielded activation of the left medial-temporal lobe; however, we found a functional dissociation within this region. The anterior and superior areas were active in episodic and semantic retrieval, whereas more posterior and inferior areas were active in autobiographical retrieval. Unique activations for each memory type were also delineated, including medial frontal increases for autobiographical, right middle frontal increases for episodic, and right inferior temporal increases for semantic retrieval. These findings suggest a common neural network underlying all declarative memory retrieval, as well as unique neural contributions reflecting the specific properties of retrieved memories.

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