The interactive effects of divided attention and semantic elaboration on associative recognition memory: an fMRI study DOI
Bradley R. Buchsbaum,

Morris Moscovitch,

Kevin Tang

et al.

Cerebral Cortex, Journal Year: 2024, Volume and Issue: 34(12)

Published: Dec. 1, 2024

The present study explored the opposing effects on memory of semantic elaboration and division attention learning recognition verbal paired associates. Previous work had found that levels recollection were reduced under divided conditions, even after equating expressed between full attention. experiments not only confirmed this finding but also participants based their largely normative values rather than subjectively achieved elaboration. In terms related brain processes, experiment 2 used functional magnetic resonance to show was associated with both prefrontal hippocampal activity a reduction in connectivity anterior hippocampus medial-orbital regions cortex. Increased increased immediately stimulus presentation. Additionally, medial-prefrontal cortex enhanced by increases conditions Our results therefore two factors influencing memory-elaboration attention-are mediated processes cortex, hippocampus, these structures.

Language: Английский

Hippocampal sharp wave ripples and coincident cortical ripples orchestrate human semantic networks DOI Open Access
Akash Mishra, Serdar Akkol, Elizabeth Espinal

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 10, 2024

Abstract Episodic memory function is predicated upon the precise coordination between hippocampus and widespread cortical regions. However, our understanding of neural mechanisms involved in this process incomplete. In study, human subjects undergoing intracranial electroencephalography (iEEG) monitoring performed a list learning task. We show sharp-wave ripple (SWR)-locked reactivation specific semantic processing regions during free recall. This activation consists both broadband high frequency (non-oscillatory) (oscillatory) activity. SWRs ripples anterior temporal lobe, major hub, co-occur increase rate prior to Coincident hippocampal-ATL are associated with greater reactivation, specificity location based on recall content, preceded by theta oscillations. These findings may represent orchestrated an interplay hippocampal SWRs, ripples,

Language: Английский

Citations

4
Declarative Memory Through the Lens of Single-Trial Peaks in High-Frequency Power DOI Open Access
Adam J. O. Dede, Zachariah R. Cross, Stephen Gray

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Summary Declarative memory depends on the coordination of local processing, indexed by high-frequency broadband (HFB) activity, with global network organization, theta oscillations. However, and HFB exhibit asynchronous timing, raising question how results processing are communicated throughout network. Using intracranial EEG in patients performing a recognition task, we examined this across medial temporal lobe (MTL) prefrontal cortex (PFC). peak activity was earlier MTL than PFC. Anchoring analyses phase clustering connectivity to peaks revealed strong locked PFC, as well between PFC that predicted individual performance. Graph analysis specific connections amidst sparse during success. This study demonstrates transient brain states linked internal physiological events support refines our understanding network-level process interactions. Highlights Memory-linked is time-locked Network changes dynamically Sparse supports successful Specific sequences may be critical for declarative

Language: Английский

Citations

0
A wireless, 60-channel, AI-enabled neurostimulation platform DOI Open Access
Daniel S. Rizzuto, Zhe Hu,

Daniel Utin

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Abstract Electrical stimulation of the human brain has emerged as a powerful therapeutic modality, enabling alteration neural circuits underlying cognition and behavior. Recent evidence indicates that stimulation’s effects on physiology behavior depend endogenous variation in state, measured by field-potential recordings. Here, we describe 60-channel brain-computer interface – Smart Neurostimulation System (SNS) combines closed-loop analysis spectral features field potential with multi-channel capabilities. We demonstrate system functionality via bench tests from an vivo ovine study exercising subset device’s functionality. Our shows SNS can reliably measure correlates (motion) physiological stimulation. safety histology following 120-day study.

Language: Английский

Citations

0
Hippocampal and cortical high frequency oscillations orchestrate human semantic networks during word list memory DOI Creative Commons
Akash Mishra, Serdar Akkol, Elizabeth Espinal

et al.

iScience, Journal Year: 2025, Volume and Issue: 28(4), P. 112171 - 112171

Published: March 13, 2025

Language: Английский

Citations

0
Dissociating physiological ripples and epileptiform discharges with vision transformers DOI Creative Commons
Da Zhang, Jonathan K. Kleen

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: April 18, 2025

Abstract Two frequently studied bursts of neural activity in the hippocampus are normal physiological ripples and abnormal interictal epileptiform discharges (IEDs). While they different waveforms, IEDs notoriously picked up as false positives when using typical automated detectors which prone to sharp edge artifacts. This has created challenges for studying independently. We leveraged recent advances computer vision on time-frequency feature representations enable more comprehensive objective dissociation these phenomena. retrospectively evaluated human intracranial recordings from 46 hippocampal depth electrode sites among 17 patients with focal epilepsy, majority whom had a seizure-onset zone/network involving hippocampus. implemented common ripple detection algorithm broadband spectrograms all detected “ripple candidates” were projected into low-dimensional space. segmented them k-means infer pseudo-labels probable IEDs. Independently, expert IED labels manually annotated comparison. State-of-the-art transformer models individual approach vs. an image classification problem. 31,847 ripple/IED candidates, median 3.9% per patient (range: 0-47.2%) based label overlap. Low-dimensional projection separated canonical better than raw or ripple-filtered waveforms. Canonical candidates emerged at opposite poles continuous landscape intermediates between. A binary model trained expert-labeled non-IED candidate 5-fold cross-validation showed mean area under curve (AUC) 0.970 precision-recall 0.694, both significantly above chance. To evaluate generalizability, we leave-one-patient-out approach, training testing data demonstrated near-expert performance (mean AUC 0.966 across patients, range 0.892-0.997). Transformer-derived attention maps revealed that tuned triangle-like artifact spatial features spectrograms. Model-derived probabilities (i.e. being IED) transitions between IEDs, opposed clustering. The delineation appears best represented gradient not binary) due overlapping sharpened and/or high frequency pathophysiological features. Vision transformers nevertheless perform virtually levels dissociating phenomena by leveraging enabled Such tools applied spectrotemporal may augment investigations cognitive neurophysiology signal biomarker optimization closed-loop applications.

Language: Английский

Citations

0
Introducing HiBoP: a Unity‐based visualization software for large iEEG datasets DOI
Maria Del Vecchio,

Benjamin Bontemps,

Florian Lance

et al.

Journal of Neuroscience Methods, Journal Year: 2024, Volume and Issue: 409, P. 110179 - 110179

Published: May 31, 2024

Language: Английский

Citations

1
Neocortico-hippocampal ripple-based coordination during naturalistic encoding DOI Creative Commons
Marta Silva, Xiongbo Wu, Marc Sabio‐Albert

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 27, 2023

Abstract Ripples are fast oscillatory events widely recognized as crucial markers for memory consolidation and neural plasticity. These transient bursts of activity thought to coordinate information transfer between the hippocampus neocortical areas, providing a temporal framework that supports stabilization integration new memories. However, their role in human encoding during naturalistic scenarios remains unexplored. Here, we recorded intracranial electrophysiological data from ten epilepsy patients watching movie. were analyzed regions (i.e., frontal cortex). Our results revealed differential dynamical pattern ripple occurrence encoding. Enhanced hippocampal recruitment was observed at event boundaries, reflecting involvement segmentation, whereas higher rates seen within an cortical electrodes with cortex weather later recalled. findings shed light on mechanisms underlying provide insights into potential ripples event, suggesting impact formation long-term memories distinct episodes.

Language: Английский

Citations

3
The interactive effects of divided attention and semantic elaboration on associative recognition memory: an fMRI study DOI
Bradley R. Buchsbaum,

Morris Moscovitch,

Kevin Tang

et al.

Cerebral Cortex, Journal Year: 2024, Volume and Issue: 34(12)

Published: Dec. 1, 2024

The present study explored the opposing effects on memory of semantic elaboration and division attention learning recognition verbal paired associates. Previous work had found that levels recollection were reduced under divided conditions, even after equating expressed between full attention. experiments not only confirmed this finding but also participants based their largely normative values rather than subjectively achieved elaboration. In terms related brain processes, experiment 2 used functional magnetic resonance to show was associated with both prefrontal hippocampal activity a reduction in connectivity anterior hippocampus medial-orbital regions cortex. Increased increased immediately stimulus presentation. Additionally, medial-prefrontal cortex enhanced by increases conditions Our results therefore two factors influencing memory-elaboration attention-are mediated processes cortex, hippocampus, these structures.

Language: Английский

Citations

0