The Time Course of Task-Specific Memory Consolidation Effects in Resting State Networks

Abstract

Previous studies have reported functionally localized changes in resting-state brain activity following a short period of motor learning, but their relationship with memory consolidation and their dependence on the form of learning is unclear. We investigate these questions with implicit or explicit variants of the serial reaction time task (SRTT). fMRI resting-state functional connectivity was measured in human subjects before the tasks, and 0.1, 0.5, and 6 h after learning. There was significant improvement in procedural skill in both groups, with the group learning under explicit conditions showing stronger initial acquisition, and greater improvement at the 6 h retest. Immediately following acquisition, this group showed enhanced functional connectivity in networks including frontal and cerebellar areas and in the visual cortex.Thirtyminuteslater,enhancedconnectivitywasobservedbetweencerebellarnuclei,thalamus,andbasalganglia,whereasat6htherewas enhanced connectivity in a sensory-motor cortical network. In contrast, immediately after acquisition under implicit conditions, there was increased connectivity in a network including precentral and sensory-motor areas, whereas after 30 min a similar cerebello-thalamo-basal ganglionicnetworkwasseenasinexplicitlearning.Finally,6hafterimplicitlearning,wefoundincreasedconnectivityinmedialtemporalcortex, but reduction in precentral and sensory-motor areas. Our findings are consistent with predictions that two variants of the SRTT task engage dissociable functional networks, although there are also networks in common. We also show a converging and diverging pattern of flux between prefrontal, sensory-motor, and parietal areas, and subcortical circuits across a 6 h consolidation period.

Consensus Paper: Towards a Systems-Level View of Cerebellar Function: the Interplay Between Cerebellum, Basal Ganglia, and Cortex

“…7Functional connectivity within a network encompassing cerebellar nuclei, the thalamus, and basal ganglia was significantly greater than at baseline 30 min after exposure to an implicit sequence learning task. Similar connectivity increase was seen for explicit learning; in both cases, this declined after 6 h. From [155] with permission …”

“…Similar connectivity increase was seen for explicit learning; in both cases, this declined after 6 h. From [155] with permission…”

“…The implication is that cerebellar processes may contribute to the consolidation of a motor skill, probably leading to long-term change in both cerebellar and cerebral sites. Second, after a similar period of learning in the serial reaction time task (SRTT, a sequence learning paradigm) [155], we again saw short-term changes within 10 min in cerebellar, frontal, and occipital areas that led to later changes, measured at 6 h after learning, within sensorimotor cortex and medio-temporal areas, perhaps reflecting long-term memory store. One group, learning under explicit conditions, showed early increased connectivity within cerebello-frontal and visual cortical areas and later increased connectivity in sensorimotor cortex.…”

Developing the catecholamines hypothesis for the acute exercise-cognition interaction in humans: Lessons from animal studies

“…They require little 243 processing and are carried out automatically. While they may have been learned explicitly and, 244 during learning, required activation of the PFC and parietal cortex, thus demonstrating top-down 245 control, with practice the roles of the prefrontal and parietal cortices diminish [68][69][70] by inhibiting second messenger cyclic adenosine monophosphate (cAMP) activation [82]. as we will see below, by interacting with DA and NE they also have effects on many cognitive 318 processes.…”

Upregulation of cortico-cerebellar functional connectivity after motor learning

“…Alternatively, cortico-cerebellar connectivity has been indirectly assessed by evaluating changes in somatosensory evoked potentials (SEP) or motor evoked potentials (MEP) (Haavik and Murphy, 2013;Andrew et al, 2015;Baarbé et al, 2014). Recent resting-state fMRI studies revealed increased functional connectivity in cortical and subcortical regions after a short course of motor learning (Vahdat et al, 2011;Ma et al, 2011;Taubert et al, 2011;Tung et al, 2013;Sami et al, 2014). These findings further emphasise the involvement of the cerebellum in motor control and the consolidation of motor memory (Raymond et al, 1996;Inoue et al, 2000;Della-Maggiore et al, 2009).…”