Sing GC & Smith MA (2010). Reduction in Learning Rates Associated with Anterograde Interference Results From Interactions Between Different Timescales. PLoS Computational Biology, 6:e10000893.
Abstract:
Prior experiences can influence future actions. These experiences can not only drive
adaptive changes in motor output, but they can also modulate the rate at which these adaptive
changes occur. Here we studied anterograde interference in motor adaptation - the ability of a
previously-learned motor task (Task A) to reduce the rate of subsequently learning a different
(and usually opposite) motor task (Task B). We examined the capacity for anterograde interference in the adaptive control of human reaching arm movements
by determining the amount of interference after varying durations of exposure to Task A (13, 41,
112, 230, and 369 trials). We found that the amount of anterograde interference observed in the
learning of Task B increased with the duration of Task A. However, this increase did not continue
indefinitely; instead, the interference reached asymptote after 15-40 trials of Task A.
Interestingly, we found that a recently-proposed multi-rate model of motor adaptation, composed
of two distinct, but interacting adaptive processes, predicts several key features of the interference
patterns we observed. Specifically, this computational model (without any free parameters)
predicts the initial growth and leveling off of anterograde interference that we describe, as well as
the asymptotic amount of interference that we observe experimentally (R^2=0.91). Understanding
the mechanisms underlying anterograde interference in motor adaptation may aid in developing
improved training and rehabilitation paradigms that mitigate unwanted interference.