From tying shoelaces to understanding neurological disorders: New research offers a fresh perspective on motor learning

How are your doctors and therapists explaining "chunking" to you to help you in your stroke recovery? Have they incorporated it into your stroke protocols? Are your therapists able to break walking into chunks and just practice a chunk at a time? One of my therapists was terrible, he gave me the 'Walk this way' demonstration, no ability to break walking into smaller manageable pieces. And I still walk like shit, probably always will until my damned spasticity is finally removed.
http://www.mdlinx.com/neurology/top-medical-news/article/2016/07/15/1

Northwestern Medicine News

Consider an everyday action such as tying shoelaces. It consists of discrete halts in movement between continuous elemental actions, such as making a loop, or tugging at the lace. As people repeat movements, these elemental actions are merged into “chunks.” A new study, led by researchers at the Rehabilitation Institute of Chicago (RIC), makes significant advances in explaining the phenomenon of movement chunking and has important implications for the early diagnosis, treatment and rehabilitation therapy for patients with neurological disorders. The field of computational motor control focuses on how the brain ought to control movements, given its goals and resource constraints (i.e., how the brain ought to optimize the efficiency of movement). In this context, researchers have had difficulty explaining how people learn to transition from computationally simple (but inefficient) movements to those that are computationally demanding (but efficient). This study resolves the issue by demonstrating that chunking is the natural by–product of a physiologically clever strategy that minimizes learning costs. The research, published in the journal Nature Communications, presents two main findings. First, it develops a theory to explain why chunking occurs. By measuring how the nervous system in monkeys produces movement sequences over several days of practice, the authors found empirical evidence that chunks occur because of a tradeoff between efficiency and computational cost. On the one hand, the nervous system aims to produce movements as efficiently as possible. On the other, there is a computational cost to calculating efficient trajectories. Chunks are the sweet spot between these goals. Second, the study demonstrates that there are certain stages during the learning of complex movements at which it is optimally cost–effective to merge small chunks. The data show that monkeys are indeed cost–effective learners whose nervous system decides when to merge chunks in an intelligent way. Specifically, the movement sequence is divided into chunks, optimizing for efficiency within chunks, and then merging chunks only when further gains in efficiency are required.