scholarly journals Theta-phase dependent neuronal coding during sequence learning in human single neurons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Leila Reddy ◽  
Matthew W. Self ◽  
Benedikt Zoefel ◽  
Marlène Poncet ◽  
Jessy K. Possel ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Field Potential ◽  
Fixed Sequence ◽  
Oscillation Phase ◽  
Theta Oscillation ◽  
Implanted Electrodes ◽  
Neuronal Coding ◽  
Phase Precession ◽  
Human Participants

AbstractThe ability to maintain a sequence of items in memory is a fundamental cognitive function. In the rodent hippocampus, the representation of sequentially organized spatial locations is reflected by the phase of action potentials relative to the theta oscillation (phase precession). We investigated whether the timing of neuronal activity relative to the theta brain oscillation also reflects sequence order in the medial temporal lobe of humans. We used a task in which human participants learned a fixed sequence of pictures and recorded single neuron and local field potential activity with implanted electrodes. We report that spikes for three consecutive items in the sequence (the preferred stimulus for each cell, as well as the stimuli immediately preceding and following it) were phase-locked at distinct phases of the theta oscillation. Consistent with phase precession, spikes were fired at progressively earlier phases as the sequence advanced. These findings generalize previous findings in the rodent hippocampus to the human temporal lobe and suggest that encoding stimulus information at distinct oscillatory phases may play a role in maintaining sequential order in memory.

scholarly journals Theta-phase dependent neuronal coding during sequence learning in human single neurons

2019 ◽  
Author(s):  
Leila Reddy ◽  
Matthew W. Self ◽  
Benedikt Zoefel ◽  
Marlène Poncet ◽  
Jessy K. Possel ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Short Term Memory ◽  
Human Subjects ◽  
Field Potential ◽  
Oscillation Phase ◽  
Theta Oscillation ◽  
Implanted Electrodes ◽  
Neuronal Coding ◽  
Phase Precession

AbstractThe ability to maintain a sequence of items in short-term memory (STM) is a fundamental cognitive function. In the rodent hippocampus, the representation of sequentially organized spatial locations is reflected by the phase of action potentials relative to the theta oscillation (phase precession). We investigated whether the timing of neuronal activity relative to the theta brain oscillation also reflects sequence order in the medial temporal lobe of humans. We used a task in which human subjects learned sequences of pictures and recorded single neuron and local field potential activity with implanted electrodes. We report that spikes for three consecutive items in the sequence (the preferred stimulus for each cell, as well as the stimuli immediately preceding and following it) were phase-locked at distinct phases of the theta oscillation. Consistent with phase precession, spikes were fired at progressively earlier phases as the sequence advanced. These findings generalize previous findings in the rodent hippocampus to the human temporal lobe and suggest that encoding stimulus information at distinct oscillatory phases may play a role in maintaining their sequential order in STM.

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.

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 Timing of Single-Neuron and Local Field Potential Responses in the Human Medial Temporal Lobe

2014 ◽  
Vol 24 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Hernan Gonzalo Rey ◽  
Itzhak Fried ◽  
Rodrigo Quian Quiroga
Keyword(s):  
Temporal Lobe ◽  
Local Field ◽  
Local Field Potential ◽  
Medial Temporal Lobe ◽  
Single Neuron ◽  
Field Potential

scholarly journals Generalising state transition structure in the human medial temporal lobe

2021 ◽  
Author(s):  
Leonie Glitz ◽  
Keno Juechems ◽  
Christopher Summerfield ◽  
Neil P Garrett
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
State Transition ◽  
Computational Modelling ◽  
State Transitions ◽  
Transition Model ◽  
Natural Environments ◽  
Sequential Decision ◽  
Transition Functions ◽  
Human Participants

Effective planning involves knowing where different actions will take us. However natural environments are rich and complex, leading to a "curse of dimensionality" - an exponential increase in memory demand as a plan grows in depth. One potential solution to this problem is to generalise the neural state transition functions used for planning between similar contexts. Here, we asked human participants to perform a sequential decision making task designed so that knowledge could be shared between some contexts but not others. Computational modelling showed that participants generalise a transition model between contexts where appropriate. fMRI data identified the medial temporal lobe as a locus for learning of state transitions, and within the same region, correlated BOLD patterns were observed in contexts where state transition information was shared. Finally, we show that the transition model is updated more strongly following the receipt of positive compared to negative outcomes, a finding that challenges conventional theories of planning which assume knowledge about our environment is updated independently of outcomes received. Together, these findings propose a computational and neural account of how information relevant for planning can be shared between contexts.

scholarly journals Content tuning in the medial temporal lobe cortex: Voxels that perceive, retrieve

2019 ◽  
Author(s):  
Heidrun Schultz ◽  
Roni Tibon ◽  
Karen F. LaRocque ◽  
Stephanie A. Gagnon ◽  
Anthony D. Wagner ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Positive Linear Relationship ◽  
Parahippocampal Cortex ◽  
Neural Populations ◽  
Human Participants ◽  
Cortical Regions ◽  
Successful Recall ◽  
Past Experiences

AbstractHow do we recall vivid details from our past based only on sparse cues? Research suggests that the phenomenological reinstatement of past experiences is accompanied by neural reinstatement of the original percept. This process critically depends on the medial temporal lobe (MTL). Within the MTL, perirhinal cortex (PRC) and parahippocampal cortex (PHC) are thought to support encoding and recall of objects and scenes, respectively, with the hippocampus (HC) serving as a content-independent hub. If the fidelity of recall indeed arises from neural reinstatement of perceptual activity, then successful recall should preferentially draw upon those neural populations within content-sensitive MTL cortex that are tuned to the same content during perception. We tested this hypothesis by having eighteen human participants undergo functional magnetic resonance imaging (fMRI) while they encoded and recalled objects and scenes paired with words. Critically, recall was cued with the words only. While HC distinguished successful from unsuccessful recall of both objects and scenes, PRC and PHC were preferentially engaged during successful vs. unsuccessful object and scene recall, respectively. Importantly, within PRC and PHC, this content-sensitive recall was predicted by content tuning during perception: Across PRC voxels, we observed a positive linear relationship between object tuning during perception and successful object recall, while across PHC voxels, we observed a positive linear relationship between scene tuning during perception and successful scene recall. Our results thus highlight content-based roles of MTL cortical regions for episodic memory and reveal a direct mapping between content-specific tuning during perception and successful recall.

Children show adult-like hippocampal pattern separation for familiar but not novel events

2020 ◽  
Author(s):  
Susan L. Benear ◽  
Elizabeth A. Horwath ◽  
Emily Cowan ◽  
M. Catalina Camacho ◽  
Chi Ngo ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Developmental Change ◽  
Pattern Separation ◽  
Developmental Changes ◽  
Similarity Analysis ◽  
Separation Processes ◽  
Parahippocampal Cortex ◽  
Pattern Similarity

The medial temporal lobe (MTL) undergoes critical developmental change throughout childhood, which aligns with developmental changes in episodic memory. We used representational similarity analysis to compare neural pattern similarity for children and adults in hippocampus and parahippocampal cortex during naturalistic viewing of clips from the same movie or different movies. Some movies were more familiar to participants than others. Neural pattern similarity was generally lower for clips from the same movie, indicating that related content taxes pattern separation-like processes. However, children showed this effect only for movies with which they were familiar, whereas adults showed the effect consistently. These data suggest that children need more exposures to stimuli in order to show mature pattern separation processes.

Sign in / Sign up

Export Citation Format

Share Document