Retraining Automaticity: Recovering the Procedural Memory of Walking after Stroke

Abstract

Walking upright, on two feet, without a cane or other assistive device -is perhaps the most ubiquitous and arguably the most human of all procedural memories. Yet, walking did not start out as a procedural memory that we were innately born able to do. How did walking become "automatic", or procedural? Is that capacity lost after stroke? The motor control for walking, while it can be adjusted for environment and task, is a relatively individualized pattern superimposed on many basic similarities from person to person. The pathway by which we develop "our" recognizable pattern of walking includes two essential ingredients. First, we need an environment that allows for locomotion as a primary means of transit (i.e., repetitions). Second, we need sufficient demand (in the form of dual task distractions) to push the organization of the motor control of gait into the more primitive structures of the basal ganglia and cerebellum. Our recognizable "walk", evolves over time and, barring injury or change in somatotype (e.g., significant weight gain or loss), remains relatively constant through our adult years. In this paper, we will discuss both what is known in regard to creating this procedural memory, and what is known about re-creating this level of automaticity, particularly after stroke.

An Evaluation of Symmetries in Ground Reaction Forces during Self-Paced Single- and Dual-Task Treadmill Walking in the Able-Bodied Men

“…In our study, the practice of walking in isolation and with dual-task demands during session 1, in addition to the period between the two assessment sessions, may all have helped to form and consolidate a new procedural memory of the walking trials before taking measurements in session 2. The procedural memory plays a crucial role in supporting motor behavior and enhancing automaticity [47], and it appears to have mitigated the detrimental effects of dual-task performance on speed parameters. Future research is warranted to further investigate the role of procedural memory in reducing dual-task effects on gait performance.…”