scholarly journals Thalamic-medial temporal lobe connectivity underpins familiarity memory

2019 ◽  
Author(s):  
Alex Kafkas ◽  
Andrew R. Mayes ◽  
Daniela Montaldi
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Dynamic Interaction ◽  
Thalamic Nuclei ◽  
Neural Basis ◽  
General Role ◽  
Anterior Thalamus ◽  
Ventrolateral Thalamus ◽  
Familiarity And Recollection

AbstractThe neural basis of memory is highly distributed, but the thalamus is known to play a particularly critical role. However, exactly how the different thalamic nuclei contribute to different kinds of memory is unclear. Moreover, whether thalamic connectivity with the medial temporal lobe (MTL), arguably the most fundamental memory structure, is critical for memory, remains unknown. We explore these questions using an fMRI recognition memory paradigm that taps familiarity and recollection (i.e., the two types of memory that support recognition) for objects, faces and scenes. We show that the mediodorsal thalamus (MDt) plays a material-general role in familiarity, while the anterior thalamus plays a material-general role in recollection. Material-specific regions were found for scene familiarity (ventral posteromedial and pulvinar thalamic nuclei) and face familiarity (left ventrolateral thalamus). Critically, increased functional connectivity between the MDt and the parahippocampal (PHC) and perirhinal cortices (PRC) of the MTL underpinned increases in reported familiarity confidence. These findings suggest that familiarity signals are generated through the dynamic interaction of functionally connected MTL-thalamic structures.

scholarly journals Thalamic-Medial Temporal Lobe Connectivity Underpins Familiarity Memory

2020 ◽  
Vol 30 (6) ◽  
pp. 3827-3837 ◽  
Author(s):  
Alex Kafkas ◽  
Andrew R Mayes ◽  
Daniela Montaldi
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Dynamic Interaction ◽  
Thalamic Nuclei ◽  
Neural Basis ◽  
General Role ◽  
Anterior Thalamus ◽  
Ventrolateral Thalamus ◽  
Familiarity And Recollection

Abstract The neural basis of memory is highly distributed, but the thalamus is known to play a particularly critical role. However, exactly how the different thalamic nuclei contribute to different kinds of memory is unclear. Moreover, whether thalamic connectivity with the medial temporal lobe (MTL), arguably the most fundamental memory structure, is critical for memory remains unknown. We explore these questions using an fMRI recognition memory paradigm that taps familiarity and recollection (i.e., the two types of memory that support recognition) for objects, faces, and scenes. We show that the mediodorsal thalamus (MDt) plays a material-general role in familiarity, while the anterior thalamus plays a material-general role in recollection. Material-specific regions were found for scene familiarity (ventral posteromedial and pulvinar thalamic nuclei) and face familiarity (left ventrolateral thalamus). Critically, increased functional connectivity between the MDt and the parahippocampal (PHC) and perirhinal cortices (PRC) of the MTL underpinned increases in reported familiarity confidence. These findings suggest that familiarity signals are generated through the dynamic interaction of functionally connected MTL-thalamic structures.

scholarly journals The Medial Temporal Lobe Is Critical for Spatial Relational Perception

2020 ◽  
Vol 32 (9) ◽  
pp. 1780-1795 ◽  
Author(s):  
Nicholas A. Ruiz ◽  
Michael R. Meager ◽  
Sachin Agarwal ◽  
Mariam Aly
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Long Term Memory ◽  
Term Memory ◽  
Cognitive Domains ◽  
Attention Tasks ◽  
Human Participants ◽  
Attention And Perception

The medial temporal lobe (MTL) is traditionally considered to be a system that is specialized for long-term memory. Recent work has challenged this notion by demonstrating that this region can contribute to many domains of cognition beyond long-term memory, including perception and attention. One potential reason why the MTL (and hippocampus specifically) contributes broadly to cognition is that it contains relational representations—representations of multidimensional features of experience and their unique relationship to one another—that are useful in many different cognitive domains. Here, we explore the hypothesis that the hippocampus/MTL plays a critical role in attention and perception via relational representations. We compared human participants with MTL damage to healthy age- and education-matched individuals on attention tasks that varied in relational processing demands. On each trial, participants viewed two images (rooms with paintings). On “similar room” trials, they judged whether the rooms had the same spatial layout from a different perspective. On “similar art” trials, they judged whether the paintings could have been painted by the same artist. On “identical” trials, participants simply had to detect identical paintings or rooms. MTL lesion patients were significantly and selectively impaired on the similar room task. This work provides further evidence that the hippocampus/MTL plays a ubiquitous role in cognition by virtue of its relational and spatial representations and highlights its important contributions to rapid perceptual processes that benefit from attention.

Familiarity and recollection vs representational models of medial temporal lobe structures: A single-case study

2017 ◽  
Vol 104 ◽  
pp. 76-91 ◽  
Author(s):  
Emilie Lacot ◽  
Stéphane Vautier ◽  
Stefan Kőhler ◽  
Jérémie Pariente ◽  
Chris B. Martin ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Single Case ◽  
Single Case Study ◽  
Familiarity And Recollection ◽  
Representational Models

scholarly journals Representations of local spatial information in the human medial temporal lobe during memory-guided navigation

2020 ◽  
Author(s):  
Shao-Fang Wang ◽  
Valerie A. Carr ◽  
Serra E. Favila ◽  
Jeremy N. Bailenson ◽  
Thackery I. Brown ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Spatial Information ◽  
Activity Patterns ◽  
Critical Role ◽  
Neural Representations ◽  
Parahippocampal Cortex ◽  
Pattern Similarity ◽  
Cortical Regions ◽  
Goal Directed Behavior

AbstractThe hippocampus (HC) and surrounding medial temporal lobe (MTL) cortical regions play a critical role in spatial navigation and episodic memory. However, it remains unclear how the interaction between the HC’s conjunctive coding and mnemonic differentiation contributes to neural representations of spatial environments. Multivariate functional magnetic resonance imaging (fMRI) analyses enable examination of how human HC and MTL cortical regions encode multidimensional spatial information to support memory-guided navigation. We combined high-resolution fMRI with a virtual navigation paradigm in which participants relied on memory of the environment to navigate to goal locations in two different virtual rooms. Within each room, participants were cued to navigate to four learned locations, each associated with one of two reward values. Pattern similarity analysis revealed that when participants successfully arrived at goal locations, activity patterns in HC and parahippocampal cortex (PHC) represented room-goal location conjunctions and activity patterns in HC subfields represented room-reward-location conjunctions. These results add to an emerging literature revealing hippocampal conjunctive representations during goal-directed behavior.

scholarly journals Theta Oscillations in the Human Medial Temporal Lobe during Real World Ambulatory Movement

2016 ◽  
Author(s):  
Zahra M. Aghajan ◽  
Peter Schuette ◽  
Tony Fields ◽  
Michelle Tran ◽  
Sameed Siddiqui ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Real World ◽  
Medial Temporal Lobe ◽  
Theta Rhythm ◽  
Human Subjects ◽  
Critical Role ◽  
Spike Timing ◽  
Theta Oscillations ◽  
Behavioral Correlates ◽  
Deep Brain

AbstractTheta oscillations play a critical role in learning and memory by coordinating the spiking activity of neuronal ensembles via mechanisms such as spike timing dependent plasticity1–7. This rhythm is present in rodents where it is continuously evident during movement at frequencies within 6-12Hz8,9. In humans, however, the presence of continuous theta rhythm has been elusive; indeed, a functionally similar theta is thought to occur at lower frequency ranges (3-7Hz) and in shorter bouts10–12. This lower frequency theta rhythm is observed during a variety of behaviors, including virtual navigation, but has never been tested during real world ambulatory movement. Here we examined the oscillatory properties of theta within the human medial temporal lobe (MTL) in freely moving human subjects chronically implanted with the clinical NeuroPace RNS® responsive neurostimulator device, capable of wireless recordings of continuous intracranial deep brain electroencephalographic (iEEG) activity. MTL iEEG recordings, together with sub-millimeter position tracking, revealed the presence of high frequency theta oscillations (6-12Hz) during ambulation. The prevalence of these oscillations was increased during fast movement compared to slow movement. These theta bouts, although occurring more frequently, were not significantly different in durations during fast versus slow movements. In a rare opportunity to study one subject with congenital blindness, we found that both the prevalence and duration of theta bouts were much greater than those in sighted subjects. Our results suggest that higher frequency theta indeed exists in humans during movement providing critical support for conserved neurobiological mechanisms for spatial navigation. The precise link between this pattern and its behavioral correlates will be an exciting area for future studies given this novel methodology for simultaneous motion capture and long term chronic recordings from deep brain targets during ambulatory human behavior.

scholarly journals The medial temporal lobe is critical for spatial relational perception

2019 ◽  
Author(s):  
Nicholas A. Ruiz ◽  
Michael R. Meager ◽  
Sachin Agarwal ◽  
Mariam Aly
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Long Term Memory ◽  
Term Memory ◽  
Cognitive Domains ◽  
Attention Tasks ◽  
Human Participants ◽  
Attention And Perception

AbstractThe medial temporal lobe (MTL) is traditionally considered to be a system that is specialized for long-term memory. Recent work has challenged this notion by demonstrating that this region can contribute to many domains of cognition beyond long-term memory, including perception and attention. One potential reason why the MTL (and hippocampus specifically) contributes broadly to cognition is that it contains relational representations — representations of multidimensional features of experience and their unique relationship to one another — that are useful in many different cognitive domains. Here, we explore the hypothesis that the hippocampus/MTL plays a critical role in attention and perception via relational representations. We compared human participants with MTL damage to healthy age- and education-matched individuals on attention tasks that varied in relational processing demands. On each trial, participants viewed two images (rooms with paintings). On ‘similar room’ trials, they judged whether the rooms had the same spatial layout from a different perspective. On ‘similar art’ trials, they judged whether the paintings could have been painted by the same artist. On ‘identical’ trials, participants simply had to detect identical paintings or rooms. Patients were significantly and selectively impaired on the similar room task. This work provides further evidence that the hippocampus/MTL plays a ubiquitous role in cognition by virtue of its relational and spatial representations, and highlights its important contributions to rapid perceptual processes that benefit from attention.

scholarly journals Semantics of the Visual Environment Encoded in Parahippocampal Cortex

2016 ◽  
Vol 28 (3) ◽  
pp. 361-378 ◽  
Author(s):  
Michael F. Bonner ◽  
Amy Rose Price ◽  
Jonathan E. Peelle ◽  
Murray Grossman
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Primary Progressive Aphasia ◽  
Semantic Knowledge ◽  
Individual Variability ◽  
Visual Environment ◽  
Parahippocampal Cortex ◽  
Visual Concepts ◽  
High Level

Semantic representations capture the statistics of experience and store this information in memory. A fundamental component of this memory system is knowledge of the visual environment, including knowledge of objects and their associations. Visual semantic information underlies a range of behaviors, from perceptual categorization to cognitive processes such as language and reasoning. Here we examine the neuroanatomic system that encodes visual semantics. Across three experiments, we found converging evidence indicating that knowledge of verbally mediated visual concepts relies on information encoded in a region of the ventral-medial temporal lobe centered on parahippocampal cortex. In an fMRI study, this region was strongly engaged by the processing of concepts relying on visual knowledge but not by concepts relying on other sensory modalities. In a study of patients with the semantic variant of primary progressive aphasia (semantic dementia), atrophy that encompassed this region was associated with a specific impairment in verbally mediated visual semantic knowledge. Finally, in a structural study of healthy adults from the fMRI experiment, gray matter density in this region related to individual variability in the processing of visual concepts. The anatomic location of these findings aligns with recent work linking the ventral-medial temporal lobe with high-level visual representation, contextual associations, and reasoning through imagination. Together, this work suggests a critical role for parahippocampal cortex in linking the visual environment with knowledge systems in the human brain.

scholarly journals A critical role for human ventromedial frontal lobe in value comparison based on multi-attribute configuration

2018 ◽  
Author(s):  
Gabriel Pelletier ◽  
Lesley K. Fellows
Keyword(s):  
Frontal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Real Life ◽  
Control Group ◽  
Object Processing ◽  
General Role ◽  
Healthy Control ◽  
Value Integration ◽  
Multiple Value

ABSTRACTReal-life decisions are often between options with multiple value-relevant attributes. Neuroeconomic models propose that the value associated with each attribute is integrated in a global value for each option. However, evidence from patients with ventromedial frontal (VMF) damage argues against a very general role for this region in value integration, suggesting instead that it contributes critically to specific value inference or comparison processes. Here, we tested value-based decision-making between artificial multi-attribute objects in 12 men and women with focal damage to VMF, compared to a healthy control group (N=24) and a control group with frontal lobe damage sparing VMF (N=12). In a ‘configural’ condition, overall object value was predicted by the conjunction of two attributes, while in an ‘elemental’ condition, object value could be assessed by combining the independent values of individual attributes. Patients with VMF damage were impaired in making choices when value was uniquely predicted by the configuration of attributes, but intact when choosing based on elemental attribute-values. This is evidence that VMF is critical for inferring the value of whole objects in multi-attribute choice. These findings have implications for models of value-based choice, and add to emerging views of how this region may interact with medial temporal lobe systems involved in configural object processing and relational memory.

scholarly journals The critical role of the ventral temporal lobe in word retrieval

2021 ◽  
Author(s):  
Kathryn M Snyder ◽  
Kiefer James Forseth ◽  
Cristian Donos ◽  
Patrick S Rollo ◽  
Simon Fischer-Baum ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Critical Role ◽  
Temporal Cortex ◽  
Intractable Epilepsy ◽  
Significant Decline ◽  
Word Retrieval ◽  
Visual Object ◽  
Confrontation Naming

Deficits in word retrieval are a hallmark of a variety of neurological illnesses spanning from dementia to traumatic injuries. The role of the dominant temporal lobe in fluent naming has been characterized by lesional analyses, functional imaging, and intracranial recordings, but limitations of each of these measures preclude a clear assessment of which specific constituent of the temporal lobe is critical for naming. We studied a large cohort of patients undergoing surgical resections or laser ablations of the dominant temporal lobe for medically intractable epilepsy (n=95). These techniques are exceedingly effective for seizure control but often result in language declines, particularly in confrontation naming, which can be socio-economically disabling. We used a multivariate voxel-based lesion symptom mapping analysis to localize brain regions significantly associated with visual object naming deficits. We observed that posterior inferior temporal regions, centered around the middle fusiform gyrus, were significantly associated with a decline in confrontation naming. Furthermore, we found that the posterior margin of anterior temporal lobectomies was linearly correlated to a decline in visual naming with a clinically significant decline occurring once the resection extended 6 cm from the anterior tip of the temporal lobe. We integrated these findings with electrocorticography during naming in a subset of this population and found that the majority of cortical regions whose resection was associated with a significant decline overlapped with regions that were functionally most active prior to articulation. Importantly, these loci coincide with the sites of susceptibility artifacts during echo-planar imaging, which explains why this region has not previously been implicated. Taken together, these data highlight the crucial contribution of the posterior ventral temporal cortex in lexical access and its important role in the pathophysiology of anomia following temporal lobe resections. Surgical strategies, including the use of laser ablation to target the medial temporal lobe as well as microsurgical approaches, should attempt to preserve this region to mitigate postoperative language deficits.

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