Matching Items (2)
Description
In motor training, transfer is defined as the gain/loss of performance in one task as a result of training on another. In our laboratory, we have observed that training on a multi-joint coordination task (which simulates arm and wrist movement when feeding) transfers to a dexterity task (which simulates finger and hand movement when dressing), such that there are improvements in the dexterity task that emerge without having trained on that specific task. More recently, we have shown that the dexterity task transfers to the multi-joint coordination task. These collective findings suggest that there are shared movement patterns between these two functional motor tasks that may yield this bi-directional transfer effect. Therefore, the objective of this thesis project was to collect kinematic data of the hand to use in future principal component analyses to better understand the underlying mechanism of transfer between these two functional motor tasks. The joint angles of the hand were recorded during twenty second trials of the multi-joint coordination task and the dexterity task. The ranges of motion for the joints in the hand during naïve performance of both motor tasks were analyzed. From a linear regression analysis, we observe that the hand’s ranges of motion were strongly correlated between the two tasks, which suggests that these two functionally different tasks may share movement patterns in terms of joint angles. This similarity of joint angles of the hand may play a role in why we observe this bi-directional transfer between the dexterity and multi-joint coordination tasks. Following neurological injury, patients participate in physical therapy in order to retrain their nervous system to restore lost motor function(s). If patients can only practice a limited number of activities in therapy, our data suggest that other activities may also improve through transfer of training. Kinematic data collection may inform how much a patient improves with motor training and why there may be an improvement in untrained motor tasks.
ContributorsConnor, Sydney Christine (Author) / Schaefer, Sydney (Thesis director) / Peterson, Daniel (Committee member) / Harrington Bioengineering Program (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Studies using transcranial direct current stimulation (tDCS) to enhance motor training areoften irreproducible. This may be partly due to differences in stimulation parameters across
studies, but it is also plausible that uncontrolled placebo effects may interact with the true
‘treatment’ effect of tDCS. Thus, the purpose of this study was to test whether there was a
placebo effect of tDCS on motor training and to identify possible mechanisms of such an effect.
Fifty-one participants (age: 22.2 ± 4.16; 26 F) were randomly assigned to one of three groups:
active anodal tDCS (n=18), sham tDCS (n=18), or no stimulation control (n=15). Participant
expectations about how much tDCS could enhance motor function and their general suggestibility
were assessed. Participants then completed 30 trials of functional upper extremity motor training
with or without online tDCS. Stimulation (20-min, 2mA) was applied to the right primary motor
cortex (C4) in a double-blind, sham-controlled fashion, while the control group was unblinded and
not exposed to any stimulation. Following motor training, expectations about how much tDCS
could enhance motor function were assessed again for participants in the sham and active tDCS
groups only. Results showed no effect of active tDCS on motor training (p=.67). However, there
was a significant placebo effect, such that the collapsed sham and active tDCS groups improved
more during motor training than the control group (p=.02). This placebo effect was significantly
influenced by post-training expectations about tDCS (p=.0004). Thus, this exploratory study
showed that there is a measurable placebo effect of tDCS on motor training, likely driven by
participants’ perceptions of whether they received stimulation. Future studies should consider
placebo effects of tDCS and identify their underlying mechanisms in order to leverage them in
clinical care.
ContributorsHAIKALIS, NICOLE (Author) / Schaefer, Sydney Y (Thesis advisor) / Honeycutt, Claire (Committee member) / Daliri, Ayoub (Committee member) / Arizona State University (Publisher)
Created2022