Contextual Expectations Shape Cortical Reinstatement of Sensory Representations

Journal of Neuroscience, Journal Year: 2022, Volume and Issue: 42(30), P. 5956 - 5965

Published: June 24, 2022

When making a turn at familiar intersection, we know what items and landmarks will come into view. These perceptual expectations, or predictions, from our knowledge of the context; however, it is unclear how memory systems interact to support prediction reactivation sensory details in cortex. To address this, human participants learned spatial layout animals positioned cross maze. During fMRI, both sexes navigated between reach target, process saw predictable sequence five animal images. Critically, isolate activity patterns related item rather than bottom-up inputs, one-fourth trials ended early, with blank screen presented instead. Using multivariate pattern similarity analysis, reveal that early visual cortex, posterior medial regions, hippocampus showed greater when seeing same compared different items. Further, effects were specific context. associated an cortex also was expected, but omitted, suggesting predictions reinstated these regions. Finally, connectivity one position later position. Together, results idea hippocampal representations facilitate processing by modulating cortical anticipation expected

Language: Английский

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Aging and Alzheimer’s disease have dissociable effects on local and regional medial temporal lobe connectivity

Brain Communications, Journal Year: 2023, Volume and Issue: 5(5)

Published: Jan. 1, 2023

Abstract Functional disruption of the medial temporal lobe-dependent networks is thought to underlie episodic memory deficits in aging and Alzheimer’s disease. Previous studies revealed that anterior lobe more vulnerable pathological neurodegenerative processes In contrast, cognitive structural imaging literature indicates posterior, as opposed anterior, vulnerability normal aging. However, extent which aging-related relate functional brain poorly understood. To address this knowledge gap, we examined connectivity alterations its immediate neighbourhood—the Anterior-Temporal Posterior-Medial networks—in agers, individuals with preclinical disease patients Mild Cognitive Impairment or mild dementia due network perirhinal cortex, particular, observed an inverted ‘U-shaped’ relationship between stage. According our results, phase characterized by increased cortex other regions lobe, well one-hop neighbours system. This effect no longer present symptomatic Instead, displayed reduced hippocampal within hypoconnectivity For aging, results led three main conclusions: (i) intra-network both declines age; (ii) posterior segments become increasingly decoupled from each advancing (iii) subregions especially parahippocampal are age-associated loss function than their counterparts. Together, current highlight evolving dysfunction indicate different neurobiological mechanisms versus

Language: Английский

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Mapping the organization and dynamics of the posterior medial network during movie watching

NeuroImage, Journal Year: 2021, Volume and Issue: 236, P. 118075 - 118075

Published: April 25, 2021

Brain regions within a posterior medial network (PMN) are characterized by sensitivity to episodic tasks, and they also demonstrate strong functional connectivity as part of the default network. Despite its cohesive structure, delineating intranetwork organization diversity PMN is crucial for understanding contributions multidimensional event cognition. Here, we probed during movie watching identify pattern connections subnetwork functions in split-sample replication 136 participants. Consistent with prior findings fractionation, identified distinct subsystems: Ventral PM subsystem (retrosplenial cortex, parahippocampal angular gyrus) Dorsal (medial prefrontal hippocampus, precuneus, cingulate anterior gyrus). subsystems were differentiated cortex precuneus integrated retrosplenial respectively. Finally, distinction between functionally relevant: whereas both tracked content, only increased strength at transitions appeared sensitive memory. Overall, these reveal pathways roles

Language: Английский

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Neural mechanisms of acceptance-commitment therapy for obsessive-compulsive disorder: a resting-state and task-based fMRI study

Psychological Medicine, Journal Year: 2023, Volume and Issue: 54(2), P. 374 - 384

Published: July 10, 2023

There is growing evidence for the use of acceptance-commitment therapy (ACT) treatment obsessive-compulsive disorder (OCD). However, few fully implemented ACT have been conducted on neural mechanisms underlying its effect OCD. Thus, this study aimed to elucidate correlates in patients with OCD using task-based and resting-state functional magnetic resonance imaging (fMRI).

Language: Английский

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Is the Papez circuit the location of the elusive episodic memory engram?

IBRO Neuroscience Reports, Journal Year: 2024, Volume and Issue: 16, P. 249 - 259

Published: Feb. 3, 2024

Language: Английский

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