Functional evidence for memory stabilization in sensorimotor adaptation: a 24h resting-state fMRI study.

DELLA MAGGIORE V, VILLALTA JI, KOVECEVIC N, MCINTOSH AR

CEREBRAL CORTEX

OXFORD UNIV PRESS INC

Lugar: Oxford; Año: 2017

1047-3211

Adaptation learning is crucial to maintain precise motor control in face of environmental perturbations. Although much progress has been made in understanding the psychophysics and neurophysiology of sensorimotor adaptation (SA) the time course of memory consolidation remains elusive. The lack of a reproducible gradient of memory resistance using protocols of retrograde interference has even led to the proposal that memories produced through SA do not consolidate. Here we pursued an alternative approach using resting-state fMRI to track changes in functional connectivity (FC) induced by learning. Given that consolidation leads to long-term memory, we hypothesized that a change in FC that predicted long-term memory but not short-term memory would provide indirect evidence for memory stabilization. Six scans were acquired before, 15min, 1h, 3h, 5.5h and 24h after training on a center-out task under veridical or distorted visual feedback. The experimental group showed an increment in FC of a network including motor, premotor, posterior parietal cortex, cerebellum, and putamen that peaked at 5.5 h. Crucially, the strengthening of this network correlated positively with long-term retention but negatively with short-term retention. Our work provides evidence suggesting that adaptation memories stabilize within a 6h window, and points to different mechanisms subserving short and long-term memory.