title: Consolidated learning can be susceptible to gradually-developing interference in prolonged motor learning.
abstract: When multiple items are learned in sequential order, learning for one item tends to be disrupted by subsequently learned items. Such retrograde interference has been studied with paradigms conducted over a relatively short term. Resistance to interference is generally believed to be a measure of learning or consolidation. Here, we used a finger-tapping motor sequence paradigm to examine interference in prolonged motor learning. Three groups of nine subjects participated in training sessions for 16 days, and practiced three different sequences in different orders and combinations. We found that a well-trained motor sequence was subject to a gradual interference when the subsequent learning was paired in a particular order. The results suggest that a well-learned motor memory is still susceptible to interference, and that resistance to interference in one condition does not necessarily imply full, permanent consolidation.
authors.affiliation: Department of Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yotsumoto
authors.forename: Takeo
authors.initials: T
authors.lastname: Watanabe
authors.forename: Li-Hung
authors.initials: LH
authors.lastname: Chang
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sasaki
keywords: consolidation; finger tapping; interference; motor learning; retrograde interference