Motor Priming in Neurorehabilitation

Abstract

Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few are practical for the current clinical environment, and the optimal priming modalities for specific clinical presentations are not known. Accordingly, developing an understanding of the various types of motor priming paradigms and their underlying neural mechanisms is an important step for therapists in neurorehabilitation. Most importantly, an understanding of the methods and their underlying mechanisms is essential for optimizing rehabilitation outcomes. The future of neurorehabilitation is likely to include these priming methods, which are delivered prior to or in conjunction with primary neurorehabilitation therapies. In this Special Interest article we discuss those priming paradigms that are supported by the greatest amount of evidence including: (i) stimulation-based priming, (ii) motor imagery and action observation, (iii) sensory priming, (iv) movement-based priming, and (v) pharmacological priming.

Movement-Based Priming: Clinical Applications and Neural Mechanisms

“…Motor priming may improve the effect of associated neurorehabilitation therapies, which might include, but are not limited to, task specific training, robotics, constraint-induced movement therapy, or gait training (for a review, see Stoykov & Madhavan, 2015). Utilization of priming plus intervention is not the same as the use of sequential interventions.…”

“…Movement-based priming is the use of any type of continuous movement that may augment the effect of the subsequent primary therapy (Stoykov & Madhavan, 2015). The priming movements can be bilateral or unilateral, active or passive, and single or multijoint.…”

“…The difference between movement-based priming and motor training is that the latter refers to goal-directed, skill-based training while the former typically refers to repetitive movement that is not skill based. For a movement to be considered as a primer, ideally the technique should have been established to either demonstrate changes in cortical excitability, or facilitate cognitive processing, thus inducing neuroplastic effects such as release of neurochemicals that may enhance the effect of subsequent training (Stoykov & Madhavan, 2015). …”

Forces That Supplement Visuomotor Learning: A “Sensory Crossover” Experiment

“…5). Response priming, when exposure to one experience influences the responses under other conditions, has been shown to be quite useful in a number of applications of human performance and learning [18, 19] and retraining of human ability after brain injury [20]. Catch trials also have the ability to slow down or interfere with learning - in the case of the Visual Rotation Group, null field catch trials can briefly interfere, while for the mixed group, catch trials in the VR condition could either offer an opportunity for priming for visual rotation or make it more difficult to adapt to the force.…”

Priming for Improved Hand Strength in Persons with Chronic Tetraplegia: A Comparison of Priming-Augmented Functional Task Practice, Priming Alone, and Conventional Exercise Training

“…Motor priming is receiving considerable attention as a way of augmenting the effects of rehabilitation-related training in neurologic clinical populations (13). Much of the early work related to motor priming to improve hand function in persons with tetraplegia centered on the use of peripheral nerve somatosensory stimulation (PNSS) (12, 14–17).…”