Title: Investigating the relationships between covert versus overt motor practice modalities and the spatial and temporal aspects of intermanual transfer
Supervisors: Dr. Nicola Hodges, Dr. Sarah Kraeutner
Committee member: Dr. Romeo Chua
Abstract:
Motor imagery (MI), the mental representation and rehearsal of a physical action without any overt movement, has been shown to measurably induce motor learning (Toth et al. 2020) and to facilitate intermanual transfer (Yao et al., 2023). As such, its potential has been demonstrated as a method for supplementing physical practice to augment learning outcomes, or to even serve as an alternative to physical practice when necessary. However, notable knowledge gaps exist regarding the mechanisms of motor imagery processes and what is encoded and generalized after motor imagery practice. Theoretically, it has been suggested that there is a ‘functional equivalence’ between covert forms of practice and overt physical practice (Jeannerod, 2001), though the extent and details of this ‘equivalence’ have been debated. For example, it has been argued that the equivalence is specific to planning stages of a neural motor program and not present in execution components (e.g., Glover et al., 2020). Moreover, there is a lack of research into the combined effects of motor imagery and physical practice and differences between motor imagery and observational learning, as another form of covert practice. In this thesis, I am proposing to fill these gaps by investigating how overt and covert practice methods can individually and collectively access, and drive transfer of, temporal versus spatial aspects of a learning task that places high demands on motor accuracy.
In a two-part experiment, I plan to first conduct individual comparisons between motor imagery, physical practice, and observational practice methods, followed by evaluation of the combined effects of the first two (when limited to one hand or distributed across both hands). I will be using a touchscreen drawing task (called ‘Tracelab’), wherein participants watch a cursor outline the form of a novel shape at varying speeds, which they are then tasked with either replicating, imagining replicating, or observing with the goal of later replicating. Before any practice, I will collect pretest performance measures from both limbs. Following a practice phase, I will collect immediate posttest measures as well as conduct delayed retention and transfer tests (comparing across limbs and across the same and different shapes that are mirrored or novel). The primary focus of analysis will be on differences between practiced and unpracticed hands at different time points (to evaluate transfer effects relative to improvement/learning effects). Based on prior research, I expect learning advantages for physical practice, though the literature is notably mixed regarding differing transfer effects between MI and observational practice. If transfer differences between physical and imagery practice are observed, I expect that imagery will result in better transfer in temporal accuracy measures, while physical practice will better drive transfer in spatial accuracy measures. Accordingly, I anticipate that there will be stronger collaboratively driven transfer through combined MI and physical practice.
Essentially, the intention of this research is to contribute unique knowledge related to what is acquired through motor imagery practice and how it could be used to augment physical practice, by testing its transfer to novel conditions including across limbs.