Movement-Based Cues Aid the Formation and Retrieval of Multiple Motor Memories

The ability to switch between different visuomotor mapping accurately and efficiently is an invaluable feature to a flexible and adaptive human motor system. This can be examined in dual adaptation paradigms where the motor system is challenged to perform under randomly switching, opposing perturbations. Typically, dual adaptation doesnt proceed unless each mapping is trained in association with a predictive contextual cue. To investigate this, in Experiment 1 I explored whether dual adaptation occurs if cued by distinct movement types (ballistic or pursuit/tracking reaches), and how adaptation to a perturbation while tracking an object generalize to ballistic reaches. Next, motivated by Experiment 1 findings that support the idea that "intrinsic" or motor-based cues (i.e., pertaining to a distinct goal) is key to dual adaptation along with recent work that shows the critical role of motor planning in dual adaptation, in Experiment 2 I looked at whether movement skew as elicited by distinct visual obstacles can facilitate dual adaptation. Next, in Experiment 3 I look at whether intrinsic cues need to be actively produced to elicit dual adaptation. Additionally, to better understand the underlying components of dual learning, I implement a Process Dissociation Procedure borrowed from cognitive sciences literature to understand the underlying explicit and implicit processes contributing to dual adaptation. In Experiment 4 I give participants an explicit strategy to drive learning where it otherwise would not occur due to an insufficient extrinsic visual cue. Finally, to understand dual adaptation in the most ecologically valid manner, in Experiment 5 I implemented the conventional virtual reality paradigm in Head-mounted VR, while also answering how the brain attributes error in this novel setup. Together, these findings provide further insight as to how the motor system plans movements and learns to adapt to an ever-changing environment, and the underlying mechanisms that drive it.