Successful Auditory Motor Adaptation Requires Task-Relevant Auditory Errors.

Abstract

When we produce speech movements, we also predict the auditory consequences of the movements. We use discrepancies between our predictions and incoming auditory information to modify our future movements (adapt). While auditory errors are crucial for speech motor learning, not all perceived auditory errors are consequences of our own actions. Therefore, the brain needs to evaluate the relevance of perceived auditory errors. Here, we examined error assessment processes involved in auditory motor adaptation by systematically manipulating the correspondence between speech motor outputs and their auditory consequences during speaking. Participants (n = 30) produced speech while they received perturbed auditory feedback (e.g., produced head but heard a word that sounded like had ). In one condition, auditory errors were related to participants productions (task-relevant errors). In another condition, auditory errors were defined by the experimenter and had no correspondence with participants speech output (task-irrelevant errors). We found that the extent of adaptation and error sensitivity (derived from a state-space model) were greater in the condition with task-relevant auditory errors in comparison to those in the condition with task-irrelevant auditory errors. Additionally, participants with smaller perceptual targets (derived from a categorical perception task) adapted more to auditory perturbations, and participants with larger perceptual targets adapted less. Similarly, participants with smaller perceptual targets were more sensitive to errors in the condition with task-relevant auditory errors. Together, our results highlight the intricate mechanisms-involving both perception and production systems-that the brain uses to optimally integrate auditory errors for successful speech motor learning.