Development and Growth of Motor Skills

The research examines how a person’s motor skills change and advance throughout their life, from childhood through adolescence and adulthood. According to Adam’s and Schmidt’s Theories of Motor Learning, the study examines the changes that take place across the time period in question. It examines the writings of philosophers like Francis Bacon, Ludvig Vicstein, and Karl Popper to study scientific theories related to motor learning, such as Practice Specificity and Practice Variability. The topics of Sensation and perception, Response Execution, Proprioception, and Response Selection with regard to motor learning are also covered in the study. Fitt’s, Weber’s, and Hick’s laws are examined in relation to how people perceive change. The paper examines the research article that analyzes the effect of degrees of freedom on motor skills such as playing of musical instruments. The control processes and models discussed herein include; closed loop control and open loop control.

Growth and Development of Motor Skills

Motor learning refers to the physical skills acquired over a period as a response to experience and practice. It is triggered by complex processes occurring in the central nervous system which result in the development of new motor skills (Krasnow & Wilmerding, 2015) Such skills are acquired either consciously of unconsciously through memories. An example of unconscious motor learning is walking. Walking is a process that occurs automatically, and any conscious effort made to control the movement results in an unnatural gait.

Another example is learning how to play a musical instrument such as a violin or a guitar. Constant repetition of the motions involved leads to the development of fine-tuned motor patterns which can unconsciously be regurgitated. However, during the initial stages of motor learning, deliberate involvement may be required, but diminishes over time are needed. Some processes such as speech are influenced by stimuli generated by the environment.

The parts of the brain that affect memory of motor patterns include the spinal cord, basal ganglia and motor cortex (Edwards, 2010).Initially, motor learning involves both practices and thought before the motions become automatic. The initial process includes sensory feedback, which is a vital component of motor skills. Phonation, involved in speech, is yet another complex motor skill that requires coordination of several muscles.

The Human Memory

According to Webb (2011), the human memory consists of three types of memory:

Short Term Sensory Store (STSS)

Short Term Store (STS)

Long Term Store (LTS)

Short Term Sensory Store

The STSS is shortest of all memory elements. Sensory memory refers to the ability to hold on to impressions long after the withdrawal of the original stimuli. The store is a form of buffer to the stimuli that is obtained due to the five senses: smell, touch, sight, smell, and taste. Such stimuli are retained briefly but accurately. Sensory memory can be demonstrated by the human ability to remember a scenario that was observed only for a short period of time, usually seconds (Webb, 2011).

The stimuli we obtained through sensory channels is either overlooked or noted. When ignored, they instantly disappear; otherwise, they are transferred into the sensory memory. The transfer happens unconsciously. The brain can detect information that will be vital later and hold on to it while allowing any other information to go unnoted. Rehearsal does not prolong the sensory memory, unlike the other forms of memory.

Iconic memory refers to the sensory memory associated with visual stimuli, while that of aural stimuli is called echoic memory. Haptic memory is associated with touch. Smell is the closest linked sense to memory and is closely related to emotions. As a result, it persists longer than other senses.

Short Term Store

Information obtained through stimuli is handed over to the short term memory where it undergoes a process that selectively concentrates on the vital aspects of the information while ignoring the rest (King, ‎Fries, & Johnson, 2014). The process is referred to as attention. The Short Term Store is useful for temporary storage of information. It is capable of remembering as well as processing information. The contents of the short term memory are readily available for a short period. It doesn’t hold entire processes but rather links or pointers to the whole process.

Long Term Memory

The information in the Short Term Storage quickly vanishes, unless a deliberate effort is made to retain the information. The conscious effort entails committing the information to the long term memory. The Long Term Memory facilitates permanent storage which can be boosted through mental repetition, giving the information meaning or linking the information to information acquired before (Srull & ‎Wyer, 2015). The learner’s motivation also influences retention in the long-term memory.

Phases of Motor development

According to Krasnow and Wilmerding (2015), the three stages of motor learning include:

Cognitive Phase

It is the initial phase of motor learning. The purpose of the stage is to experience and develop a general understanding of the motor skill. The learner, whether child or adult, must identify the intended purpose of the skill and determine the environmental factors that may influence their ability to perform. During the learning phase, the learner heavily depends on visual input to progress and employs mainly trial and error techniques. During the early development years, the child first observes the people walking around him or her. With time they begin to understand the purpose of walking. After a while, the child attempts to imitate the action and may appear awkward or clumsy initially. This is the stage at which the child begins to transition from understanding to executing the skill.

Associative Phase

  The Associative stage is the intermediate stage of motor learning. A learner within the stage displays smoother more refined actions as a result of constant repetition of the action. At the point, the student is more experienced and can picture different scenarios and stimuli, progressing from the ‘how’ to ‘what’ of the action (Krasnow & Wilmerding, 2015). Proprioceptive cues become more and more significant while the importance of visual cues gradually diminishes. The learner begins to focus more on the manner in which their bodies maneuver in space depending on the input caused by their muscles and joints. With continued practice, the learner receives more precise proprioceptive cues and grows better at the skill (Goldstein, Naglieri, & DeVries, 2011). Building on the walking example from the cognitive stage, during the initial stages of walking, the child may take small shaky steps with their arms up in a protective stance. However, during the associative stage, the child progresses to more refined movements, taking longer and more stable steps with their arms more relaxed.

Autonomous Phase 

It is the final stage of learning characterized by mainly automatic the motor skills. At the stage, the learner can perform any skills smoothly and automatically regardless of the environment. The child can walk, for instance, in a homely environment as well as, a crowded park or road. The learning process, however, varies in length from one individual to another. Progression is dependent on factors such as neuromuscular or musculoskeletal impairments, feedback, practice schedules, and the learner’s motivation. 

Motor Learning in Childhood

While adults experience an easier time learning and performing various versions of a skill, children experience a much harder time learning the same. Adults exhibit stronger retention from one day to the next and can re-learn a pattern at a much faster rate compared to children. Children below 12 years of age show a much lower retention since they experience a washout during the periods of no practice (Gollhofer, Taube & Nielsen, 2013). It can be addressed by reducing the times of no practice, such that the child practices more at the plateau of the learning curve. However, even with the hack, the retention cannot rise to the level of adults.

It is a clear indicator that ability to commit to memory an adapted version of a motor pattern doesn’t occur until a child reaches adolescence. Furthermore, the techniques that boost faster re-learning and recollection of adapted motor skills remain the same. Decreasing the level of feedback during practice promotes motor learning. Among children, however, it is impossible to apply the same principle since children possess a lower information-processing capability compared to adults. The participants registered an improvement in both accuracy and consistency during the trials (Edwards, 2010). During practice, adults have been known to perform with significantly better than the children.

In addition, studies conducted have concluded that children who receive little or no feedback during the practice period perform with inconsistently and less accurate compared to the children who worked with feedback. However, children who are used to performing without feedback portray greater improvement during the subsequent performances compared to those accustomed to receiving feedback. It is therefore advisable that children undergo long hours of practice while gradually reducing feedback to optimize motor learning.

Motor Learning in Adolescents

During the adolescent years, individuals experience a growth spurt in which both girls and boys feel equal strengths. However, beyond the adolescent years, males have the upper hand compared to females. During the periods of accelerated growth, adolescents often develop awkward movements due to larger bodies and longer limbs while the brain goes through an adjustment period. (Krasnow & Wilmerding, 2015).

Because most people become less active as they approach middle age, strength is relatively reduced towards the later adolescent years. Regular exercise is vital in improving and mastering a motor skill, as well as boosting energy levels. Children, on the contrary, are not able to handle the as much strain as adults since their bones are not yet mature. They engaging in sports from an early age are much more likely to be injured similar to children who watch their weights through dieting for purposes of sports such as wrestling or gymnastics (Goldstein et al., 2011).

Motor Control Theories

A motor program refers to the way manner in which our mind controls our bodies to achieve a particular action. It refers to a sequential set of actions that enable a person to perform a given operation correctly. In a game of cricket, such actions would include feet placement, stance, bat grip and backswing and follow through. Such routines are usually reserved in the long term memory and only retrieved during the performance.

Closed-Loop Theory

The theory is also referred to as Adam’s Theory of Motor Learning. It applies mainly to slow movements, for example, balancing on a beam and does not translate well with fast movements. It focuses on the importance of continuous intrinsic feedback which is useful in altering the movement produced by comparing the memory trace already in storage with the perceptual trace that is ongoing (Kelso, 2014). It is based on the following:

The brain is the main decision maker.

Each piece of information is delivered individually.

The muscles translate information into movement which is initiated to movement

Feedback is mandatory in initiation of the correct movements and adjustments.

Once the specific motor program has been determined, movement control is achieved through either the open-loop theory or the closed loop theory (Goldstein et al., 2011).

Open-Loop Theory

The Open-loop theory accounts for ballistic or swift movements, for example, the tennis serve. Such movements provide feedback only after the movement has been completed and therefore do not provide intrinsic feedback (Rosenbaum, 2014). As a result, such movements often leave no time for reaction or change of movement. It is based on the following:

The brain makes all decisions before acting.

Each movement is controlled by a single message.

The muscles are responsible for executing the received messages regarding movement.

The presence or absence of feedback does not control the action.

Schmidt’s Theory of Motor Learning (Schema)

The Schmidt’s theory of motor development challenges both the closed and open-loop theories. The theory suggests that motor programs can be subdivided into groups which can then be altered according to the situation at hand. Furthermore, it suggests that adaptation to a new situation is directly proportional to the extent to which motor program was achieved during practice (Donna, ‎Wilmerding & Virginia, 2015). The Theory attempts to explain the process involved in learning and performing of discrete and perceptual motor skills. Discrete skills refer to those skills require a short period to perform and are characterized by a definite beginning and end point. They engage the senses to perceive what is happening and then engage the body to perform the action.

A good example of the theory discussed is a game of tennis or badminton ( L’Abate, 2015). The player is not able to anticipate all the possible shots they may have to tackle while on the field, but they can modify the strokes they already know to suit the situation. Such actions are commonly referred to as “novel skills”.

The Schmidt’s Theory also addresses the notion derived from previous theories that each motor skill requires a separate Motor Programme. Since through our lifetimes we can learn numerous individual actions, the question that arises is how it is possible to store all these motor programs within our long-term memory (Goldstein et al., 2011). According to Schmidt’s theory, since most of the actions we perform are most likely unique actions, it is not the fixed muscle instructions that lead a person to be skillful. In order to perform a skill, according to Schmidt, three points are required:

Generalized Motor Programme

Recall Schema

Recognition Schema.

Generalized motor programme. It refers to basic movements such as kicking or catching a ball. A generalized motor program generates several versions of the same action.

Recall schema. Recall schema happens before movement and requires the performer to possess certain information before forming the schema. The initial conditions may include:

the position of the goal posts, team mates, and the opposing team;

the current environment: wet, dry, windy;

the current condition of the player.

The Response specification is dependent on factors such as the speed at which the performer needs to move, the target of his shooting, the distance that the ball needs to cover to reach its target and the technique that will guarantee the best results.

Recognition schema. Recognition schema comes into the picture during and after the duration of performance of the skill. Depending on the degree of deviation between the two, it is possible to determine the error made (McKibbon, Wilczynski, 2013). According to the Schmidt theory, after a performer generates movement, the following are stored in the memory:

The initial conditions that preceded the movement, for example, the proprioceptive details of the body and limbs.

The response parameters such as force and speed.

The sensory repercussions of the said response, which reveal details about the action such as how it felt, sounded and looked.

The outcome of the movement, especially the response outcome, which is information on the actual result of the movement based on knowledge of results (KR).

In order to correct or alter a response, an individual needs to know:

Response Outcomes.

It is usually based on the Knowledge of Results (KR), which is either Failure or Success.

The final result is compared to the intended outcome. The memory store is then updated for future reference in case one ever finds themselves in a similar situation (Kelso, 1982).

Sensory Consequence

The sensory effect is derived from the knowledge of Performance (KP). It entails what the performance looked like (extrinsic feedback) and how it felt (intrinsic feedback).

These are the feelings experienced both during and after the movement. It includes the kinesthetic feeling, the sounds and any other details that are received through the sensory system. Based on this information, suitable alterations can now be made. The ways in which Knowledge of Result can be manipulated for memory development.

Manipulation of the Knowledge of Result

Such a manipulation is vital in memory development since it improves a solution and can also facilitate elimination of errors (Kelso, 1982). It is achievable through various forms of manipulation:1. Absolute frequency manipulation. (In the case, the number of KR is manipulated while maintaining a constant number of responses.)

2. Frequency manipulation. (Frequency manipulation is when the KR is maintained at a constant value while the number of responses is varied.)

The Summary of KR manipulates the number of KR as well as its place. The guidance hypothesis suggests that the lower the value of KR, the greater the benefit. To improve performance, the value of KR should fall while the variation should increase. Lower KR means less guidance and as a result more learning. A high value of KR has been known to produce results that are artificially enhanced.

A Comparison of Adam’s and Schmidt’s Theories of Motor Learning

Under Adam’s theory, recognition is referred to as perpetual trace and is useful in the updating of control responses after determining their level of correctness. Perpetual trace is an example of closed loop control since its response is dependent on the feedback produced by the reply and it is useful in fixing movements based on knowledge. The strength of recognition rises with an increase in the number of trials as long as the prior outcomes are employed in the correction of errors. Recall, on the other hand, is referred to as memory trace and is useful in producing a response based on feedback (McKibbon & ‎Wilczynski, 2009). Under memory trace, each response is represented individually. The proper response is selected and initiated depending on the determination of the learner. Adam’s Theory of Motor learning encourages learners to practice a given event over and over.

On the contrary, under the Schmidt’s theory of motor learning, recall is referred to as recall schema, and it is useful in the initiation and carrying out of responses. It is usually based on the knowledge of response specifications and preexisting conditions. It is an example of open loop control since the feedback is received only after a controlled response. Recognition, on the other hand, is referred to as recognition schema and is based on the outcome of sensory actions. Updates occur after execution of the response (Webb, 2011).

Schmidt’s theory covers the Theory of Schema, which asserts that the memory is a representation of varied responses to the same situation; therefore, one memory is sufficient to recall and to reproduce the required response as well as the feedback that determines progressive movements. Schmidt’s theory suggests that practicing various scenarios of the same situation is a more effective way of learning.

Similarities between Schmidt’s and Adam’s Theories

Both theories assert that response execution and motor programming are equal.

Under both theories, motor learning comprises of Recognition and Recall

Both methods are used to describe paradigms.

Paradigms Used to Study Motor Learning

The paradigms used to study motor learning include:

Practice Specificity

Practice variability.

Practice specificity suggests that entirely specific, and can only be variations of skill or come close in resemblance. Practice variability, on the other hand, suggests that practicing with variations of the same task is vital in memory development regarding memory retention. It has proved to be most beneficial, where new skills are employed, as opposed to situations that have been encountered previously. Under the theory, execution of movements is seen as a fresh movement rather than a literal reproduction of prior experience (Rosenbaum, 2014).The variability of practice has yielded results that prove it to be superior to the specificity of practice thus significantly improving parameterization.

Specificity of practice hypothesis suggests that the most efficient form of learning occurs when practice involves movements and environmental conditions that closely mimic the actions that will be performed during the actual task. It attempts to recreate the context of the performance and replicate the required skills. In some studies, the specific nature of practice has been proved to aid the development of a movement structure especially during the early years of childhood (McKibbon & ‎Wilczynski, 2009).

Comparison between Practice Specificity and Practice Variability

Practice specificity can be considered as a transformation of the abilities occurring during both practice and performance. Within the learning phase, sensory information is acquired, which is later transformed into performance. The method has been observed as more helpful when the learner takes the time to observe more skilled performer acting under the same specific conditions.

Practice Variability, on the other hand, is characterized by constantly varying the conditions in which the actions are performed. Constant practice under the same conditions does not necessarily result in better outcomes. On the contrary, acting in varied ways has been proved to yield better results. Schmidt’s theory of motor learning is based on practice variability. The learner is sure to make relatively more mistakes during the practice session but is often better prepared for performances in the future.Random Practice vs. Block Practice

Both types of the methods of practice include conceptual interference, which is brought about whenever the context under which learning occurs directly interferes with the learning process (McKibbon, & ‎Wilczynski, 2009). The concept mentioned has been known to degrade the learner’s performance during the practice period significantly, but boost performance in the future. Random practice refers to a learning technique whereby a scenario is practiced differently with each consecutive trial. Such a concept is supported by Schmidt’s theory (Yan & Yick, 2017). On the other hand, Block practice involves the performance of the same action consecutively without interruptions from any other measures. Each action must be mastered before proceeding to the next. Adam’s theory supports this concept.

Initially, the block appears to be the more successful practice. However, beyond twenty-four hours, random practice gains steadily on the block, eventually proving to be superior as Random practice involves memory reconstruction without interference. It makes it the more distinctive and useful method. Under block practice, there is no comparison of the variations. The processes ranked in order of superiority include random practice, variation practice, and block practice. Such variations are based on both order and type boost memory.

Signal Detection Theory in Motor Learning

The signal detection theory states that the ability to detect stimulus depends on the intensity of the stimulus is as well as the psychological and physical state of the individual experiencing the stimulus. It suggests that human beings only notice things based on the intensity that they emanate and how much attention we are giving to our surroundings. The theory claims there exists a threshold below which human beings are not able to detect a stimulus. The problem, however, is that this threshold is yet to be established (Yan & Yick, 2017).

What was discovered, is that sensory sensitivity is a function of signal strength and the degree of alertness. It is the origin of the signal detection theory. The realization that sensory sensitivity depends on the individual making a conscious decision to notice is what defines this theory. It is not considered enough for an individual to detect a signal; he has to identify it as well.

Contributions of Philosophers: Theories that Surround Motor Learning.

Francis Bacon: Test of disproof. In science, a critical experiment is one that is capable of coming to a decisive conclusion on whether or not a theory or hypothesis is superior in all aspects to all the other theories and hypotheses that are widely accepted within the scientific community. A critical experiment should be able to prove beyond reasonable doubt that it is indeed superior to all others by producing results that disapprove all the other hypotheses or theories and therefore, clearly demonstrating that under similar internal and external conditions the alternative hypotheses can be proved false, but the experimenter’s hypothesis cannot be ruled out. Francis Bacon described the concept as instantiated Crucis.

Such an experiment must be produced for the theory or hypothesis to become an established part of scientific knowledge. In the history of science most theories are usually developed first before critical experiments are performed and produced (Srull & ‎Wyer, 2015). A given theory that can be matched to a known experiment is considerable for exploration even if the critical experiment is yet to be produced. However, in various situations, a proposed theory could account for abnormal experimental results, which have no other explanation. A new theory cannot be established based on such experiments since the results are not considered to be convincing enough to support a theory.

Ludwig Wittgenstein’s ”picture theory of language”. (Solving scientific concepts through word problems). Ludwig’s theory is based on the idea that any problems to do with philosophy can be traced to the misunderstandings of logical language. Important concepts of the theory include:

’Logical constants’ are not representatives since the logic of facts cannot be represented.

Propositions display reality in a logical form.

The things that can be shown cannot be said.

Propositions assume the form. It is the stand on things.

All the propositions of logic bear the same message.

The essence of a proposition is the core of the description of all things including the world.

The limits of language are the limits of the world.

According to the picture theory of meaning, propositions are only useful for as long as they picture the state of affairs and empirical facts. Anything abnormal or metaphysical is therefore considered to be nonsense. However, the ”picture theory“ is observed to deny sense to even the frameworks that support it. In this way, the theory disapproves itself (Rathus, 2013).

Karl Popper’s theory ”you cannot prove what you cannot disprove”. The theory of Karl Popper is based on the fact that science is unable to prove anything since it is based purely on observations and experiments, which are highly prone to flaws. Initially, the flaws are hidden from the scientific community but with time become quite apparent. Flaws during the experimental phase most certainly lead to inaccurate and biased conclusions. As a result, even the most widely believed scientific statements remain unproven despite the fact that extensive evidence supporting them is in existence.

Inequality of Scientific Paradigms

Hypothetical constructs

A hypothetical construct refers to a variable that cannot be directly observed. A good example is a measurement of a person’s happiness. Performing such measurements has often proved to be problematic usually for the obvious reasons; that the construct being measured is not tangible, but rather abstract. The results obtained from such an experiment can be biased and ambiguous. Determining whether a person is in love would be a difficult task since views of love vary widely among people. As a result, a hypothetical construct does not hold much water, so its validity is weak.

Despite the fact that the constructs are difficult to measure, they are necessary to study, and therefore compromises have to be made. Factors such as the development of the mind cannot be precisely measured; creating a need to infer from their behavior rather than making accurate measurements. The Rubin’s love scale, however, enables the study of such constructs scientifically. It achieves this through the use of questionnaires. Happiness, for instance, can be measured in three ways: use of a questionnaire to determine how happy a person is, physically observing people’s body language and finally measuring physiology through the study of brain waves, heart rate, blood pressure and hormone levels (Srull & ‎Wyer, 2015).

The Mismeasure of Man

The Mismeasure of Man promotes a theory of innate, unitary and linearly ranked intelligence. An example is a craniometry, which is the use of skull volume to determine intellectual capability. Jay Gould faulted the research claiming that the research was biased along social and racial prejudices of the researchers who allowed their expectations to influence their analysis and conclusions.

Relevant Laws that Affect Memory and Motor Learning

Fitts’s Law 

Fitt’s law attempts to predict the movement of a human being. It states that the total time needed to reach a target depends on the distance between the individual and the target, divided by the width of the target. Fitts’s law models the action of pointing to the target, either through touching or merely pointing. Fitts’s law applies a broad range of conditions and many limbs, including hands, eye gaze, lower lip, feet, etc. (King et. al., 2014. The law further proposes the concept of an index of performance which acts as a meter for human performance.

The metric utilizes index of difficulty (ID) of the task together with the time the movement is likely to span, to identify the target. According to Fitts, ”The rate of information generated through a sequence of movements is, on average, equal to the information per individual movement divided by the time spanned by each movement.” (Gollhofer et al., 2013). Fitt’s law is, therefore, appropriate in the modeling of rapid or ballistic movements in which case the limb begins at a specified point and proceeds to rest within the area of the target.

Hick’s Law

Hick’s Law stipulates that increasing the number of choices a person has while deciding, increases the time taken to make a decision logarithmically. The law is useful in assessing the capacity for cognitive information in experiments that require making of choices. The time taken to process the bits of information is referred to as the rate of information gain.

Hick’s law, in a way, is similar to Fitts’s law. Hick’s law takes on a logarithmic aspect since when faced with a decision, people tend first to subdivide the choices into smaller groups, and then proceed stepwise by eliminating the choices categorically, as opposed to confronting the whole collection and eliminating one by one. The latter would apply linear time.

Motor Learning through “Freeing and Freezing Degrees of Freedom”

From the perspective of motor control, motor learning is regarded as the process that facilitates movement coordination through neural control. In such a case, coordination of movements is achieved through mastery of the body’s degrees of freedom (Webb, 2011). In order to simplify the process, it is important to eliminate redundant degrees. It can be achieved through freezing of certain joints within the chain of kinematics. Freezing can be defined as the complete locking of a joint.

In the case where an individual is learning how to play the violin, to fully understand the problem of control posed to a novice learner, the researchers have to consider the fact is bowing actions may require controlling the degrees of freedom associated with the wrist, shoulder and elbow joints. On the contrary, the degrees of freedom associated with the hand are already fixed since the task of grasping the bow constrains the fingers. Additionally, bowing does not require rotation of both the radioulnar joint, as well as the humerus since the bow is held in place by a string.

However, the two vital, degrees-of-freedom left-right and up-down, bowing motions, have to be controlled through coordination of the five degrees of freedom, including shoulder abduction, radial and ulnar deviation of the wri...