%0 Journal Article %A Krista M. Bond %A Jordan A. Taylor %T Structural Learning in a Visuomotor Adaptation Task Is Explicitly Accessible %D 2017 %R 10.1523/ENEURO.0122-17.2017 %J eneuro %P ENEURO.0122-17.2017 %X Structural learning is a phenomenon characterized by faster learning in a new situation that shares features of previously experienced situations. One prominent example within the sensorimotor domain is that human participants are faster to counter a novel rotation following experience with a set of variable visuomotor rotations. This form of learning is thought to occur implicitly through the updating of an internal forward model, which predicts the sensory consequences of motor commands. However, recent work has shown that much of rotation learning occurs through an explicitly accessible process, such as movement re-aiming. We sought to determine if structural learning in a visuomotor rotation task is purely implicit (e.g., driven by an internal model) or explicitly accessible (i.e., re-aiming). We found that participants exhibited structural learning: following training with a variable set of rotations, they more quickly learned a novel rotation. This benefit was entirely conferred by the explicit re-aiming of movements. Implicit learning offered little to no contribution. Next, we investigated the specificity of this learning benefit by exposing participants to a novel perturbation drawn from a statistical structure either congruent or incongruent with their prior experience. We found that participants who experienced congruent training and test phase structure (i.e., rotations to rotation) learned more quickly than participants exposed to incongruent training and test phase structure (i.e., gains to rotation) and a control group. These results suggest that structural learning in a visuomotor rotation task is specific to previously experienced statistical structure and expressed via explicit re-aiming of movements.Significance Statement Structural learning is a meta-learning phenomenon evidenced by an accelerated learning rate for novel tasks sharing the same statistics as the training task. Previous investigations suggest that this effect is driven by the implicit extraction of invariant task features. However, this interpretation contrasts with recent research showing that an explicitly accessible process, such as movement re-aiming, accounts for most of rotation learning. We investigated (1) whether structural learning in a visuomotor rotation task was explicitly accessible and (2) whether structural learning was specific to the trained perturbation structure or expressed via a general aiming heuristic. Our results suggest that structural learning in a visuomotor rotation task is specific to previously experienced statistical structure and expressed via movement re-aiming. %U https://www.eneuro.org/content/eneuro/early/2017/08/10/ENEURO.0122-17.2017.full.pdf