Increased cortical inhibition following brief motor memory reactivation supports reconsolidation and overnight offline learning gains

Abstract

Practicing motor skills stabilizes and strengthens motor memories by repeatedly reactivating and reconsolidating them. The conventional view, by which a repetitive practice is required for substantially improving skill performance, has been recently challenged by behavioral experiments, in which even brief reactivations of the motor memory have led to significant improvements in skill performance. However, the mechanisms which facilitate brief reactivation-induced skill improvements remain elusive. While initial memory consolidation has been repeatedly associated with increased neural excitation and disinhibition, reconsolidation has been shown to involve a poorly understood mixture of both excitatory and inhibitory alterations. Here, we followed a 3-d reactivation–reconsolidation framework to examine whether the excitatory/inhibitory mechanisms which underlie brief reactivation and repetitive practice differ. Healthy volunteers practiced a motor sequence learning task using either brief reactivation or repetitive practice and were assessed using ultrahigh field (7T) magnetic resonance spectroscopy at the primary motor cortex (M1). We found that increased inhibition (GABA concentrations) and decreased excitation/inhibition (glutamate/GABA ratios) immediately following the brief reactivation were associated with overnight offline performance gains. These gains were on par with those exhibited following repetitive practice, where no correlations with inhibitory or excitatory changes were observed. Our findings suggest that brief reactivation and repetitive practice depend on fundamentally different neural mechanisms and that early inhibition—and not excitation—is particularly important in supporting the learning gains exhibited by brief reactivation.

Randomized trial on the effects of an EMDR intervention on traumatic and obsessive symptoms during the COVID-19 quarantine: a psychometric study

“…This new form of learning may allow the event to be reprocessed in a way that is adaptive and no longer dysfunctional ( 102 ). As a matter of fact, once memory is retrieved, it may become labile again, which fosters its susceptibility to modification during a possible process of human memory reconsolidation ( 103 , 104 ). Paying attention to the positive features after negative recall (like during the identification of positive cognition during the EMDR protocol) may lead to increased levels of positive emotion and modifications in memory content during recollection 1 week later, remaining even after 2 months.…”

Inhibitory mechanisms in the prefrontal-cortex differentially mediate Putamen activity during valence-based learning

“…Here, we used magnetic resonance spectroscopy (MRS), which allows the non-invasive measurement of GABA (27,28), and functional magnetic resonance imaging (fMRI) to measure brain activity. 117 participants performed probabilistic learning tasks under gain and loss conditions during MRS and fMRI scanning at an ultra-high 7T field strength.…”

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“…This new form of learning may allow the event to be reprocessed in a way that is adaptive and no longer dysfunctional (102). As a matter of fact, once memory is retrieved, it may become labile again, which fosters its susceptibility to modification during a possible process of human memory reconsolidation (103,104). Paying attention to the positive features after negative recall (like during the identification of positive cognition during the EMDR protocol) may lead to increased levels of positive emotion and modifications in memory content during recollection 1 week later, remaining even after 2 months.…”