Movement sonification can improve motor control in both healthy subjects (e.g., learning or refining a sport skill) and those with sensorimotor deficits (e.g., stroke patients and deafferented individuals). It is not known whether improved motor control and learning from movement sonification are driven by feedback-based real-time (“online”) trajectory adjustments, adjustments to internal models over multiple trials, or both. We searched for evidence of online trajectory adjustments (muscle twitches) in response to movement sonification feedback by comparing the kinematics and error of (...) reaches made with online (i.e., real-time) and terminal sonification feedback. We found that reaches made with online feedback were significantly more jerky than reaches made with terminal feedback, indicating increased muscle twitching (i.e., online trajectory adjustment). Using a between-subject design, we found that online feedback was associated with improved motor learning of a reach path and target over terminal feedback; however, using a within-subjects design, we found that switching participants who had learned with online sonification feedback to terminal feedback was associated with a decrease in error. Thus, our results suggest that, with our task and sonification, movement sonification leads to online trajectory adjustments which improve internal models over multiple trials, but which themselves are not helpful online corrections. (shrink)

Studies of visual event individuation often consider people's representations of activities involving agents performing complex tasks. Concomitantly, theories of event individuation emphasize predictions about agents' intentions. Studies that have examined simple, non-agential occurrences leave open the possiblity that principles of visual object individuation play a role in visual event individuation. Unearthing principles that may be sufficient for event individuation which are distinct both from predictions about agents' intentions and from visual object individuation, we draw on and extend studies that reveal (...) object and event representation to be deeply analogous in our cognitive economy. We provide evidence that ‘temporal shaping' is a sufficient low-level perceptual criterion for the visual individuation of events. In our study, temporal shaping is effected by the introduction of pauses into an otherwise continuous process. Future studies should address other visual mechanisms for introducing temporal shaping (e.g., color changes). (shrink)