Memory after poor practice is contingent on subsequent experience: behavioral evidence supporting the Synaptic Tagging and Capture hypothesis in motor memory consolidation

Abstract

Abstract The Synaptic Tagging and Capture hypothesis (STC), addressing hippocampal-dependent memory, explains how memory for a poor learning experience, one that would soon decay, can be enhanced if temporally paired with a ‘strong’, consolidation-triggering, experience. Only ‘strong’ experiences generate cellular plasticity-related-products necessary for synaptic re-modeling; but synapses engaged in a ‘weak’ learning experience can capture and utilize plasticity-related-products generated for a ‘strong’ learning experience that precedes or follows the ‘weak’ one. Here we show, in young adults (N = 100), that limited practice in performing a novel sequence of finger-to-thumb opposition movements, leads to different long-term outcomes depending on whether and when (5-minutes, 5-hours) it is followed by extensive training on a different sequence. The 5-minute pairing, only, resulted in robust overnight gains for the limited-trained sequence and these gains were well-retained a week later; the overnight gains for the extensive-trained sequence were compromised. These results are in line with the STC notion of a capture of cellular resources necessary for synapse re-modeling, generated for the extensive-trained movement sequence, by task-specific synapses temporally ‘tagged’ during the limited training session. This suggests that the STC can apply to and well explain key phenomena in human behavior related to motor (procedural, non-hippocampus dependent) memory.