The purpose of this paper is to discuss current theories, concepts and research involving Motor Learning. The research provides evidence-based information discussing how humans utilize motor-learning throughout the lifespan. The discussion includes stages of motor learning, practice contexts, feedback and use of imagery in motor learning. Also provided is information concerning how people learn who have disabilities resulting from at least two different conditions, Parkinson's which affects motor learning and stroke.
Motor Learning Acquisition
According to Li, Sullivan, Kantak, & Winstein (2007), the capability of acquiring motor learning requires "both cognitive and motor processes" meaning mental processes including the ability to make decisions and plan, and interpret, as well as motor processes including the ability to move muscles and perform mechanical tasks. When an individual can use neurological functions to compute tasks and plan, then these can translate into a motor function. The first step in motor learning is development of the cognitive ability, including the ability to anticipate a motor action and regulate a motor action. When an infant is born for example, they have little ability to motor regulate, which is why the limbs flop about and have little ability to self-regulate. As the motor learning process continues to develop over time, the motor process functions gradually develop, allowing more complex actions such as crawling, toddling, and walking. Fingering foods are examples of the development of motor learning processes.
Motor learning is associated with various processes which include neuromuscular stimulation which occurs when electrical impulses are sent via the brain to the muscle. Neuroplasticity is the process whereby synaptic connections are modified or the circuitry that exists between the brain and muscle, connected through the spinal cord, becomes modified in response to demands made between the brain and the body. There are various modifications that can happen or re-organization of the neural pathways that can occur in the neuroplasticity of the body or neural pathways that occur when an injury occurs or disease occurs in the CNS system. At the cellular level in the body, there can be greater sensitivity to the neuropathways or neural transmitters that send electrical messages from the brain to the muscles, making for hyper responses and there can be strengthened synaptic connections, or the opposite can be true in some cases.
Typically people view motor learning from voluntary motor learned responses; there are many maps in the body that make up the learning experience of the motor learning process or circuitry of electrical impulses in the brain. Fine motor control consists of the acute or fine connections that exist when certain connections are made from processes that are learned. Consider when an individual learns to be very dexterous or has to learn to develop very complex processes using the hands. Learning how to type is a motor learning process. Some individuals who lose the use of their hands or fingers eventually learn to develop the use of writing skills with their toes instead of using their fingers. Certain individuals can learn to develop motor learning skills using their mouthpiece as a writing instrument by holding a pen with it, becoming very dexterous in this respect. All of this requires fine motor learning skills development. Factors that can promote greater motor learning may include the loss of sensory input from certain areas, including severe injury to one of the major mapping areas or sensory input systems, or failure to function adequately in one areas such as may be the case in Parkinson's or resulting from a stroke. A paralyzed limb or limbs may also be cause for using or mobilizing other areas or sensory areas of the body. Typically rather than acquiring new skills motor learning results in new learning or functional gains in other areas. This requires rapid growth sometimes in certain areas of the circuitry in the body. Therapy will consist of identifying areas that require growth or strengthening. Improved performance, increased sensory input, reduction of spasticity and stiffness and improved task ability may all be goals of motor learning rehabilitation for patients and therapists.
Many different elements affect motor learning, including the senses. If any of these are impaired, then motor learning may be inhibited. Sight, hearing, sense of smell…all may affect motor learning. Psychological status may also affect motor learning, as may cognitive factors including anxiety. Reasoning and ability to concentrate might also affect motor learning. Cognitive deficits represent opportunities for a framework for creating rehabilitative functions in motor learning. When a neurological injury occurs, one of the functions of therapists includes identifying the motor learning or functional task difficulty so that motor practice conditions can be developed for therapy (Lin, et al., 2007). Often factors including decreased sensation and input can influence motor learning as much as damage to sensory neuronal or sensory cortical connection (Lin et al., 2007). This is why it is critical for researchers to explore all factors when examining individual patients for motor learning deficits and rehabilitation protocols.
Hubbard, Parsons, Neilson & Carey (2009) explore task-specific training as a neuromotor intervention in patients undergoing neurological rehabilitation noting patients with experience-dependent and learning-dependent motor learning changes may benefit from this type of training. Evidence suggest that task-oriented training may help in work-related rehabilitation especially with regard to upper limb motor learning tasks, especially for post-stroke limb recovery. Task-specific training is training involving motor tasks where patients receive feedback for tasks that require feedback for activities completed according to Hubbard, et al. (2009). Motor learning activities in a neurological rehabilitative environment may occur under various practice environments where improved performance and goal-directed activities oriented toward "repetitive action" may be the focus of performance as well as "functional related tasks" rather than "fixing" motor related impairments (Hubbard, et al. 2009). This type of motor learning therapy is also known as task-related or repetitive task training. This is not the same as muscle strengthening or physical strength training.
This type of motor learning training results in "neural plastic changes" that may not be sufficient to effect "changes in cortical representation" but rather effect changes specific to skills acquisition, associated with "learning-dependent models of neural plasticity" (Hubbard, p. 176). The researchers in this study suggest that "cortico-motor neuron pools are organized relative to specific tasks rather than specific muscles" so that motor skill learning can be retained in patients with specific injuries, such as stroke victims, and improvement may be seen almost as relevant to that of healthy individuals (Hubbard, p. 176).
Parkinson's is an example of a disease that progressively destroys the basal ganglia in the neurological center of the brain; the results in motor and cognitive deficits (Lin, et al., 2007). There is not much evidence right now that decidedly identifies the extent to which these deficits affect motor learning capability however. Lin & researchers (2007) suggest that cautious approaches should be taken as evidence to date suggest that "the degree to which adults with specific brain damage would benefit from low relative frequencies of post movement feedback" are likely to be strong but this cannot be certain, thus further research is required to determine translation of motor learning principles of motor learning rehabilitation for certain patients including Parkinson's patients as individual differences including skill level and practice conditions can have enormous effects including detrimental ones on patients.
This information is confirmed by other studies suggesting that in some patients postural control may benefit certain patients; for example, use of a tilt table or VR training (virtual reality training) may help motor learning or dual-task conditions in some patients with neurological deficits (Yen, et al. 2011). The same researchers also found that CB trainings were also helpful for improved "sensory integration for postural control" in patients with PD, "particularly when they were deprived of sensory redundancy" (Yen, p. 862). Further empirical evidence shows however that balance training was helpful, but only in single task conditions and not under dual task conditions. There is much evidence suggesting that motor learning is a very specific developmental process, that has to occur under certain conditions, and cannot be forced or clumped into traditional "packaged" or forced onto a person under too much stress or demand. If it is, it may actually result in sensory overload, or result in additional injury or imbalance to the individual.
Wulf, Landers, Lewthait, & Tollner (2009) also review balance and patients with movement motor learning deficits particularly related to postural instability related to internal focus, noting that reduction of fall risk may be reduced by directing attention to "movement effects external to the mover" (p. 162). This suggests that task learning and repetition again, may be a critically important skill relative to motor learning deficit and skills acquisition. External focus benefits in this instance are relative to "internal focus conditions" and to "control conditions" (p. 163). In this instance, as in other findings, the researchers note that with regard to motor learning, when there is nothing else to pay attention to, individuals tend to direct their attention internally, or to…