Reporting affects explicit knowledge in visuomotor rotations in ways not measured by reporting

Abstract

Visuomotor rotations are frequently used to study cognitive processes underlying motor adaptation. Explicit aiming strategies and implicit recalibration are two of these processes. A large body of literature indicates that these two processes are dissociable and perhaps even independent components. Various direct and indirect methods have been used to dissociate the two processes. Discrepancies have been found between these different methods. They may arise for different reasons, but one reason may be that the different measures reflect different components of explicit and implicit knowledge. They may also be because of effects of the measurements themselves on the amount of explicit and implicit learning. The goal of this study was to directly compare verbal reporting, a direct measure of explicit knowledge, with indirect measures. We thus compared three different measures in two different conditions: during consistent reporting and during intermittent reporting. Our results show that our two conditions lead to a dissociation between the measures. In the consistent reporting group, all measures showed similar results. However, in the intermittent reporting condition, verbal reporting showed less explicit and more implicit knowledge than our two indirect methods. Verbal reporting seems to be insensitive to the changes in explicit knowledge caused by reporting. These findings suggest that verbal reporting reflects different components of explicit knowledge than those reflected in our indirect measures. A more sophisticated approach, including multiple components of explicit knowledge, may be necessary in order to fully understand motor adaptation.