Functional network interactions at rest underlie individual differences in memory ability

Abstract

Intrinsic network interactions may underlie individual differences in the ability to remember. The default mode network (DMN) comprises subnetworks implicated in memory, and interactions between the DMN and frontoparietal network (FPN) were shown to support mnemonic processing. However, it is unclear if such interactions during resting-state predict episodic memory ability. We investigated whether intrinsic network interactions within and between the DMN and FPN are related to individual differences in memory performance. Resting-state activity was measured using functional MRI in healthy young adults followed by a memory test for object–location associations that were studied 3 d earlier. We identified two subnetworks within the DMN, the main-DMN and the medial temporal lobe, retrosplenial cortex (MTL_RSC)-DMN. Further, we found regions forming the FPN. Memory performance was associated with lower connectivity within the MTL_RSC-DMN, and stronger connectivity between the main-DMN and FPN. Exploratory whole-brain analysis revealed stronger MTL connectivity with the left posterior parietal cortex that was related to better memory performance. Furthermore, we found increased task-evoked activation during successful retrieval within the main-DMN and FPN, but not within the MTL_RSC-DMN. In sum, lower intrinsic connectivity within the MTL_RSC-DMN, combined with stronger connectivity between the main-DMN and FPN, explain individual differences in memory ability.

Spindle - slow oscillation coupling correlates with memory performance and connectivity changes in a hippocampal network after sleep

“…In the literature, the hippocampus, temporal lobe regions, and the retrosplenial cortex are often regarded as part of the default mode network because they show strong coherence during rest (Greicius et al, 2003;Vincent et al, 2006). However, recently a 'medial temporal' subnetwork has been identified, whose decrease in connectivity over sleep was associated with increased spatial memory performance (Barnett et al, 2020;van Buuren et al, 2019). Core regions of this network include the medial temporal lobe and the retrosplenial cortex.…”

“…Similar to sleep-dependent consolidation, event representations are spontaneously reactivated in the hippocampal-thalamo-cortical network during post-encoding rest (for a detailed review, see Tambini & Davachi, 2019). Important nodes of these reactivations are thought to incorporate the hippocampal network centered on the medial temporal lobe, medial temporal cortex, and retrosplenial cortex (van Buuren et al, 2019), as well as interactions between hubs of the default mode network (Lin et al, 2017) and task-relevant networks (e.g., the executive control network Sneve et al, 2017). Greater levels of resting-state functional connectivity between areas specific to the stimuli and the hippocampus were shown to predict the future ability to retrieve a memory (Tambini et al, 2010).…”

Placebo-induced pain reduction is associated with inverse network coupling at rest

“…Network connectivity implies oscillatory synchrony between neuronal assemblies which is thought to facilitate information processing (Buzsaki and Draguhn, 2004). Certain brain networks, such as the FPN and the DMN, are often negatively correlated during resting-state (Fox et al, 2005; but see for example van Buuren et al, 2019) as well as during cognitively demanding tasks ; but see Douw et al, 2016), whereby the magnitude of inverse coupling was linked to better task performance Cole et al, 2012). Thus, negative between-network connectivity appears to affect information transfer in a functionally relevant manner.…”

Plasma NFL Disrupt Cognitive Integrity Via Coupling the Interactions of Core Subsystem and Frontoparietal Network in Alzheimer's Disease

“…From the perspective of AD pathology, Aβ and tau were mainly deposited in the DMN and FPN [12,13]. From the perspective of functional interaction, DMN and FPN are cooperative rather than competitive networks [14,15], and the interactions are associated with mnemonic processing [11]. The FPN comprises the lateral prefrontal cortex, dorsal anterior cingulate cortex, precuneus, anterior inferior parietal lobule, and the inferior temporal cortex, appear to be involved in instantiating and exibly modulating cognitive control [16].…”

“…Not only interactions within the DMN but also associations between the DMN and other large-scale networks, in particular the frontoparietal network (FPN) [11]. From the perspective of AD pathology, Aβ and tau were mainly deposited in the DMN and FPN [12,13].…”