Motor Programs

Cross references:
Early Behavior   Perinatal Behavior 
  Learned Behavior    



My overall comment:     

There was no mention of   Behavioral Disinhibition   in any of the references.  The only mention of GABA was in the   5.1 Striatum and basal ganglia    section of the  "Procedural memory" reference. 


Searching Google for "motor programs" uncovered 3,820,000 references: 
https://www.google.com/search?q=motor+programs&ie=utf-8&oe=utf-8  



Motor system (Wiki) 
    "The motor system is the part of the central nervous system that is involved with movement. It consists of the pyramidal and extrapyramidal system.

Contents

My comment
    Although the article says "
The motor impulses originates in the Giant pyramidal cells or Betz cells of the motor area i.e. precentral gyrus of cerebral cortex.", there is no discussion of how movements are motivated.     


2006   73<349     Free Article   
Biological pattern generation: the cellular and computational logic of networks in motion. 
http://www.ncbi.nlm.nih.gov/pubmed/17145498    
    from the Abstract
    "In 1900, Ramón y Cajal advanced the neuron doctrine, defining the neuron as the fundamental signaling unit of the nervous system. Over a century later, neurobiologists address the circuit doctrine: the logic of the core units of neuronal circuitry that control animal behavior. These are circuits that can be called into action for perceptual, conceptual, and motor tasks, and we now need to understand whether there are coherent and overriding principles that govern the design and function of these modules. The discovery of central motor programs has provided crucial insight into the logic of one prototypic set of neural circuits: those that generate motor patterns."  


2005    84<349
Mechanisms for selection of basic motor programs--roles for the striatum and pallidum
.
http://www.ncbi.nlm.nih.gov/pubmed/15935487
     "The nervous system contains a toolbox of motor programs in the brainstem and spinal cord--that is,
neuronal networks designed to handle the basic motor repertoire required for survival, including locomotion, posture, eye movements, breathing, chewing, swallowing and expression of emotions. The neural mechanisms responsible for selecting which motor program should be recruited at a given instant are the focus of this review.  
    Motor programs are kept under tonic inhibition by GABAergic pallidal neurons (the output nuclei of the basal ganglia). The motor programs can be relieved from pallidal inhibition through activation of striatal neurons at the input stage of the basal ganglia. It is argued that the striatum has a prominent role in selecting which motor program should be called into action."  
    My comment
What determines which motor program the striatum selects?    
   See:  Tonic Inhibition for full Abstract, Similar articles and Cited by's . 


1996 
Neurons, networks, and motor behavior
http://www.ncbi.nlm.nih.gov/pubmed/8789940
    This is an introduction to "The International Symposium on Neurons, Networks, and Motor Behavior held in Tucson, Arizona (November 8–11, 1995)". 
    See:  Central Pattern Generators   for an extended summary, Related citations and Cited by's. 



Procedural memory (Wiki) 
    Abstract
    "Procedural memory is memory for the performance of particular types of action. Procedural memory guides the processes we perform and most frequently resides below the level of conscious awareness. When needed, procedural memories are automatically retrieved and utilized for the execution of the integrated procedures involved in both cognitive and motor skills, from tying shoes to flying an airplane to reading. Procedural memories are accessed and used without the need for conscious control or attention. Procedural memory is a type of long-term memory and, more specifically, a type of implicit memory. Procedural memory is created through "procedural learning" or, repeating a complex activity over and over again until all of the relevant neural systems work together to automatically produce the activity. Implicit procedural learning is essential for the development of any motor skill or cognitive activity.

    Note: come back to: implicit memory .

Contents

1 History
  •     "In the 1980s much was discovered about the anatomy physiology of the mechanisms involved in procedural memory. The cerebellum, hippocampus, neostriatum, and basal ganglia were identified as being involved in memory acquisition tasks.[2]"       
  •     "The difference between procedural and declarative memory systems was first explored and understood with simple semantics. Psychologists and Philosophers began writing about memory over a century ago. "Mechanical memory" was first noted in 1804 by Maine de Biran. William James, within his famous book: The Principles of Psychology (1890), suggested that there was a difference between memory and habit. Cognitive psychology disregarded the influence of learning on memory systems in its early years, and this greatly limited the research conducted in procedural learning up until the 20th century.[1] The turn of the century brought a clearer understanding of the functions and structures involved in procedural memory acquisition, storage and retrieval processes.

    McDougall (1923) first made the distinction between explicit and implicit memory. In the 1970s procedural and declarative knowledge was distinguished in literature on artificial intelligence. Studies in the 1970s, divided and moved towards two areas of work, one focusing on animal studies and the other to amnesic patients. The first convincing experimental evidence for a dissociation between declarative memory ("knowing what") and non-declarative or procedural ("knowing how") memory was from Milner (1962), by demonstrating that a severely amnesic patient, Henry Molaison, formerly known as patient H.M., could learn a hand–eye coordination skill (mirror drawing) in the absence of any memory of having practiced the task before. Although this finding indicated that memory was not made up of a single system positioned in one place in the brain, at the time, others agreed that motor skills are likely a special case that represented a less cognitive form of memory. However, by refining and improving experimental measures, there has been extensive research using amnesic patients with varying locations and degrees of structural damage. Increased work with amnesic patients led to the finding that they were able to retain and learn tasks other than motor skills. However, these findings had shortcomings in how they were perceived as amnesic patients sometimes fell short on normal levels of performance and therefore amnesia was viewed as strictly a retrieval deficit. Further studies with amnesic patients found a larger domain of normally functioning memory for skill abilities. For example, using a mirror reading task, amnesic patients showed performance at a normal rate, even though they are unable to remember some of the words that they were reading. In the 1980s much was discovered about the anatomy physiology of the mechanisms involved in procedural memory. The cerebellum, hippocampus, neostriatum, and basal ganglia were identified as being involved in memory acquisition tasks.[2]"  


  • 2 Acquisition of skill 
  •  
  •     Working Memory
  •     Models of working memory primarily focused on declarative until Oberauer suggested that declarative and procedural memory may be processed differently in working memory.[3] The working memory model is thought to be divided into two subcomponents; one is responsible for declarative, while the other represents procedural memory.[4][5] These two subsections are considered to be largely independent of each other.[6] It has also been determined that the process for selection may be very similar in nature when considering either modality of working memory .[7]  

  •      "Acquisition of skill

  •     The acquisition of skill requires practice. Merely repeating a task alone, however, does not ensure the acquisition of a skill. Skill acquisition is achieved when an observed behaviour has changed due to experience or practice. This is known as learning and is not directly observable.[8] The information processing model, which incorporates this idea of experience, proposes that skills develop from the interaction of four components central to information processing.[8] These components include: processing speed, the rate at which information is processed in our processing system; breadth of declarative knowledge, the size of an individual's factual information store; breadth of procedural skill, the ability to perform the actual skill; and processing capacity, synonymous with working memory. The processing capacity is of importance to procedural memory because through the process of proceduralization an individual stores procedural memory. This improves skill usage by linking environmental cues with appropriate responses.

One model for understanding skill acquisition was proposed by Fitts (1954) and his colleagues. This model proposed the idea that learning was possible through the completion of various stages. The stages involved include:

  • Cognitive phase[9][10]
  • Associative phase[9][10]
  • Autonomous phase (also called the procedural phase)[9][10]"   
  •     "


  • A countless number of potential procedures

    At this point in Fitts' (1954) model of skill acquisition individuals come to understand what an observed skill is composed of. Attention at this point in the process is significant for the acquisition of skill. This process involves breaking down the desired skill to be learned into parts and understanding how these parts come together as a whole for the correct performance of the task. The way an individual organizes these parts is known as schemas. Schemas are important in directing the acquisition process and the way an individual comes to choose schemas is described by metacognition.[9][10]"       

  •         "Associative phase

    The associative phase of the Fitts (1954) model involves individuals repeated practice until patterns of responding emerge. At this part in the model, actions of the skill become learned (or automated) as ineffective actions are dropped. An individual's sensory system acquires the accurate spatial and symbolic data required for the completion of the skill. The ability to differentiate important from unimportant stimuli is crucial at this stage of the model. It is held that the greater the amount of important stimuli associated with a task, the longer it will take to complete this phase of the model.[9][10]"      

  • 3 Tests
  • 4 Expertise
  • 5 Anatomical structures
  •        

    Striatum and basal ganglia

    For more details on the Striatum, see Striatum.
    For more details on the Basal Ganglia, see Basal ganglia.
    The Basal Ganglia is highlighted light purple

    The dorsolateral striatum is associated with the acquisition of habits and is the main neuronal cell nucleus linked to procedural memory. Connecting excitatory afferent nerve fibers help in the regulation of activity in the basal ganglia circuit. Essentially, two parallel information processing pathways diverge from the striatum, both acting in opposition to each other in the control of movement, they allow for association with other needed functional structures[34] One pathway is direct while the other is indirect and all pathways work together to allow for a functional neural feedback loop. Many looping circuits connect back at the striatum from other areas of the brain; including those from the emotion-center linked limbic cortex, the reward-center linked ventral striatum and other important motor regions related to movement.[35] The main looping circuit involved in the motor skill part of procedural memory is usually called the cortex-basal ganglia-thalamus-cortex loop.[36]

    The striatum is unique because it lacks the glutamate-related neurons found throughout most of the brain. Instead, it is categorized by a high concentration of a special type of GABA related inhibiting cell known as the medium spiny neuron.[37] The two parallel pathways previously mentioned travel to and from the striatum and are made up of these same special medium spiny neurons. These neurons are all sensitive to different neurotransmitters and contain a variety of corresponding receptors including dopamine receptors (DRD1, DRD2), Muscarinic receptors (M4) and Adenosine receptors (A2A). Separate interneurons are known to communicate with striatal spiny neurons in the presence of the somatic nervous system neurotransmitter acetylcholine.[38]

    Current understanding of brain anatomy and physiology suggests that striatal neural plasticity is what allows basal ganglia circuits to communicate between structures and to functionally operate in procedural memory processing.[39]

      

       

    Cerebellum

    For more details on the Cerebellum, see Cerebellum.
    The cerebellum is highlighted red

    The Cerebellum is known to play a part in correcting movement and in fine-tuning the motor agility found in procedural skills such as painting, instrument playing and in sports such as golf. Damage to this area may prevent the proper relearning of motor skills and through associated research it has more recently been linked to having a role in automating the unconscious process used when learning a procedural skill.[40] New thoughts in the scientific community suggest that the cerebellar cortex holds the holy grail of memory, what is known to researchers as "the engram" or the biological place where memory lives. The initial memory trace is thought to form here and then travel outwards to other brain nuclei for consolidation via parallel fibers known as Purkinje cells.[41]

     

       

    Limbic system

    For more details on the Limbic System, see Limbic system.

    The limbic system is a group of unique brain areas that work together in many interrelated processes involved in emotion, motivation, learning and memory. Current thinking indicates that the limbic system shares anatomy with a component of the neostriatum already credited with the major task of controlling procedural memory. Once thought to be functionally separate, this vital section of the brain found on the striatum's back border has only recently been linked to memory and is now being called the marginal division zone (MrD).[42] A special membrane protein associated with the limbic system is said to concentrate in related structures and to travel towards the basal nuclei. To put things simply, the activation of brain regions that work together during procedural memory can be followed because of this limbic system associated membrane protein and its application in molecular and immunohistochemistry research.[43]

      

  • 6 Physiology

       

    Dopamine

    For more details on Dopamine, see Dopamine.
    Dopamine Pathways in the brain highlighted in Blue

    Dopamine is one of the more known neuromodulators involved in procedural memory. Evidence suggests that it may influence neural plasticity in memory systems by adapting brain processing when the environment is changing and an individual is then forced to make a behavioural choice or series of rapid decisions. It is very important in the process of "adaptive navigation," which serves to help different brain areas respond together during a new situation that has many unknown stimuli and features.[44] Dopamine pathways are dispersed all over the brain and this allows for parallel processing in many structures all at the same time. Currently most research points to the mesocorticolimbic dopamine pathway as the system most related to reward learning and psychological conditioning.[45]


    At the synapse

    Recent findings could help explain the relationship between procedural memory, learning and synaptic plasticity at the level of the molecule. One study used small animals lacking normal levels of CREB family transcription factors to look at the processing of information in the striatum during various learning tasks. Although poorly understood, results show that CREB function is needed at the synapse for linking the acquisition and storage of procedural memory.[46]

      

  • 7 Disorders
  • 8 Drugs

       

    Cocaine

    For more details on Cocaine, see Cocaine.

    It is evident that long-term Cocaine abuse alters brain structures. Research has shown that the brain structures that are immediately affected by long-term cocaine abuse include: cerebral hypoperfusion in the frontal, periventricular and temporal-parietal.[62] These structures play a role in various memory systems. Furthermore, the drug cocaine elicits its desirable effects by blocking the DRD1 dopamine receptors in the striatum, resulting in increased dopamine levels in the brain.[62] These receptors are important for the consolidation of procedural memory. These increased dopamine levels in the brain resultant of cocaine use is similar to the increased dopamine levels in the brain found in schizophrenic's.[63] Studies have compared the common memory deficits caused by both cases to further understand the neural networks of procedural memory.To learn more about the effects of dopamine and its role in schizophrenia see: dopamine hypothesis of schizophrenia. Studies using rats have shown that when rats are administered trace amounts of cocaine, their procedural memory systems are negatively impacted. Specifically, the rats are unable to effectively consolidate motor-skill learning.[64] With cocaine abuse being associated with poor procedural learning, research has shown that abstinence from cocaine is associated with sustained improvement of motor-skill learning (Wilfred et al.).

     

       

    Psychostimulants

    For more details on Psychostimulants, see Psychostimulant.

    Most psychostimulants work by activating dopamine receptors causing increased focus or pleasure. The usage of psychostimulants has become more widespread in the medical world for treating conditions like ADHD. Psychostimulants have been shown to be used more frequently today amongst students and other social demographics as a means to study more efficiently or have been abused for their pleasurable side effects.[65] Research suggests that when not abused, psychostimulants aid in the acquisition of procedural learning. Studies have shown that psychostimulants like d-amphetamine facilitates lower response times and increased procedural learning when compared to control participants and participants who have been administered the antipsychotic haloperidol on procedural learning tasks.[66] While improvements in procedural memory were evident when participants were administered traces of psychostimulants, many researchers have found that procedural memory is hampered when psychostimulants are abused.[67] This introduces the idea that for optimal procedural learning, dopamine levels must be balanced.

      

  • 9 Sleep
  • 10 Languages
  • 11 See also
  • 12 Footnotes

Most important section:       


5.1 Striatum and basal ganglia
   
    The striatum is unique because it lacks the glutamate-related neurons found throughout most of the brain. Instead, it is categorized by a high concentration of a special type of GABA related inhibiting cell known as the medium spiny neuron.[37] The two parallel pathways previously mentioned travel to and from the striatum and are made up of these same special medium spiny neurons. These neurons are all sensitive to different neurotransmitters and contain a variety of corresponding receptors including dopamine receptors (DRD1, DRD2), Muscarinic receptors (M4) and Adenosine receptors (A2A). Separate interneurons are known to communicate with striatal spiny neurons in the presence of the somatic nervous system neurotransmitter acetylcholine.[38]   


[37] 
    "
Although the existence of thalamostriatal projections has long been known, the role(s) of this system in the basal ganglia circuitry remains poorly characterized. The intralaminar and ventral motor nuclei are the main sources of thalamic inputs to the striatum. This review emphasizes the high degree of anatomical and functional specificity of basal ganglia–thalamostriatal projections and discusses various aspects of the synaptic connectivity and neurochemical features that differentiate this glutamate system from the corticostriatal network. It also discusses the importance of thalamostriatal projections from the caudal intralaminar nuclei in the process of attentional orientation. A major task of future studies is to characterize the role(s) of corticostriatal and thalamostriatal pathways in regulating basal ganglia activity in normal and pathological conditions."  

[38] 
    "
The neostriatum (dorsal striatum) is composed of the caudate and putamen. The ventral striatum is the ventral conjunction of the caudate and putamen that merges into and includes the nucleus accumbens and striatal portions of the olfactory tubercle. About 2% of the striatal neurons are cholinergic. Most cholinergic neurons in the central nervous system make diffuse projections that sparsely innervate relatively broad areas. In the striatum, however, the cholinergic neurons are interneurons that provide very dense local innervation. The cholinergic interneurons provide an ongoing acetylcholine (ACh) signal by firing action potentials tonically at about 5 Hz. A high concentration of acetylcholinesterase in the striatum rapidly terminates the ACh signal, and thereby minimizes desensitization of nicotinic acetylcholine receptors. Among the many muscarinic and nicotinic striatal mechanisms, the ongoing nicotinic activity potently enhances dopamine release. This process is among those in the striatum that link the two extensive and dense local arbors of the cholinergic interneurons and dopaminergic afferent fibers. During a conditioned motor task, cholinergic interneurons respond with a pause in their tonic firing. It is reasonable to hypothesize that this pause in the cholinergic activity alters action potential dependent dopamine release. The correlated response of these two broad and dense neurotransmitter systems helps to coordinate the output of the striatum, and is likely to be an important process in sensorimotor planning and learning. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 590–605, 2002"  

*

Motor control (Wiki)   
    "Motor control is the process by which humans and animals use their neuromuscular system to activate and coordinate the muscles and limbs involved in the performance of a motor skill. Fundamentally, it is the integration of sensory information, both about the world and the current state of the body, to determine the appropriate set of muscle forces and joint activations to generate some desired movement or action. This process requires cooperative interaction between the central nervous system and the musculoskeletal system, and is thus a problem of information processing, coordination, mechanics, physics, and cognition.[1][2] Successful motor control is crucial to interacting with the world, not only determining action capabilities, but regulating balance and stability as well.

The organization and production of movement is a complex problem, so the study of motor control has been approached from a wide range of disciplines, including psychology, cognitive science, biomechanics and neuroscience. While the modern study of motor control is an increasingly interdisciplinary field, research questions have historically been defined as either physiological or psychological, depending on whether the focus is on physical and biological properties, or organizational and structural rules.[3] Areas of study related to motor control are motor coordination, motor learning, signal processing, and perceptual control theory.

Contents

  • 1 Sensorimotor feedback
  • 2 Coordination
  • 3 Perception in Motor Control
  • 4 Physiological Basis of Motor Control
  • Motor Units

    Daily tasks, for instance walking to the bathroom, talking to one of your friends or eating dinner, all require multiple muscles that innervate body parts to move properly in order to complete specific tasks. Motor units that consist tens, hundreds or even thousands of motor nerves branches are connected to the muscles. In our body, Rectus femoris contains approximately 1 million muscles fibers which are controlled by around 1000 of motor nerves. Within one motor units which can categorized to type I (slow twitch) or Type II fibers (fast twitch), the composition type of the muscle fiber will be consistent (homogeneous); whereas within one muscle, there will be several different combination of two types of motor units (heterogeneous).[28]

    There are three primary types of muscle fibers: Type I, Type IIa and Type IIb. As described above, Type I muscle fibers are known as slow twitch oxidative, Type IIa are fast twitch oxidative and Type IIb are fast twitch glycolytic. These three different types of fibers are specialized to have unique functionalities. Type I fibers are described as high endurance but low Force/Power/Speed production, Type IIb as low endurance but high Force/Power/Speed production and Type IIa fibers are characterized in between the two.

    A
    Nervous system organization

    Motor units are multiple muscle fibers that are bundled together. When a person wants to move their body, in order to achieve a certain task, the brain instantly sends out an impulse signal that reaches the specific motor unit through the spinal cord. After receiving the signal from the brain, the motor unit contracts muscle fibers within the group thus creating movement. There is no partial firing in the motor unit, meaning, once the signal is detected, all the muscles fibers within the unit contract. However, there are different intensities. Since each motor unit contracts 100% of its fiber once stimulated, types of motor unit that generate different force or speed are significant.

    Fiber Type—Contraction Speed—Time to Peak Power—Fatigue

    I (slow twitch) -------slow--------------100 milliseconds--------slowly

    IIA (fast twitch) -----fast-----------------50 milliseconds--------fast

    IIB (fast twitch) -----very fast-----------25 milliseconds--------fast


    • 4.2 Mechanism and structure of motor unit
    •     "

      Low-threshold motor units vs high-threshold motor units

      For low intensity tasks, smaller motor units with fewer muscle fibers will be used. These smaller motor units are known as low threshold motor units. They consist of type I fibers that contract much slower and thus provide less force for daily basic movement such as typing on the keyboard. For more intense tasks, motor units containing Type II muscle fibers will be utilized. These fast twitch motor units are known as high threshold motor units. The major difference between low threshold motor units (slow twitch motor unit) and high threshold motor units (fast twitch motor unit) is that high threshold motor units control more muscle fibers and contain larger muscle fibers, in comparison to low threshold motor unit. On the other hand, the main difference between the slow twitch muscle fiber (Type I) and fast twitch muscle fiber (Type II) has the same theory of the size deviations.[29]

      "  See also:  Fast vs. Slow Twitch Muscles  .     

            "

Order of recruitment of motor unit

During an activity of lifting heavy objects such as working out with a dumbbell, not only does low-threshold motor units, but also the high threshold motor units are recruited to compensate forces required in addition to just holding a fork, in which the energy created by the low threshold motor units is sufficient to complete the job. When giving a job, the body first recruits the slow-twitch motor units following by recruit more a more fast-twitch motor units as forces required to complete the movements increase. Thus, when the body has to carry an extremely massive object, it would recruited all the available motor units to contract for the particular muscle that has been used.

               High|
                   |                                     _________________
 Force required    |                                    /
                   |                                   |
                   |                                   |
                   |                      _____________|_________________
                   |           __________|_______________________________
                Low|__________|__________________________________________    
                              ↑          ↑             ↑                   Time
              Type I Recruit first    Type II A      Type IIB

The type of fiber (type I vs Type II) is controlled by the nervous system. The brain is the central information center that sent out the signal to the nerves, that the nerves control and connect the motor units. For two different motor units present, the body adopt it with two different nerves to control them. Fast twitch motor units are controlled by fast-twitch nerves while Slow twitch motor units are controlled by slow twitch nerves.[30]

In the laboratory, a nerve from a motor unit that is connected to a slow-twitch muscle fiber was replaced with a nerve that are designated for a fast-twitch fiber. The slow-twitch fiber behaved identically as a fast-twitch fiber. In contrast, if the process was reversed, the fast twitch fiber performed as a slow twitch fiber as well.[31] However, the nerves can not possibly transform from fast motor nerves into slow motor nerves and vice versa.

In many sports movements, the durations of certain action usually are within 200 milliseconds, and from the above charts, time to peak power of the individual muscle fibers of each type (I, IIA, IIB) is sufficient to reach peak power production. This brings out a question: what is the superiority of having more Type II fibers?

This can be documented when one analyzes a large group of athletes for vertical jump performance and their execution for a vertical jump. Athletes with more fast-twitch fibers (Type II) change direction quicker during their movement such as left to right direction and they tend to use less knee bend.[32] These results can be confirmed by muscle biopsy and even by special force-plate analysis. This does not mean that athletes with lower fast-twitch fiber cannot jump higher, but they tend to do it a little slower and with a deeper knee bend.

Although having a high percentage of Type II fibers gives a person more quicker movement, there is little doubt[according to whom?] that the nervous system and the brain is more important on affecting the performance.

The majority of the time, the real limit to athletes' performance is the number of motor units their nervous systems can recruit in the short period of time and the amount of forces (size of the muscle fibers) provided of those motor units. The performance is rarely affected by the type of muscle fiber (slow twitch or fast) that constructed to motor units. The nervous system determines the degree of motor unit activated in sport-like activities.

It normally takes 0.4 – 0.6 seconds for the nervous system to activate available muscle motor units to contract, the same length of time demonstrating maximum strength or force. However, vertical jump activity only takes 0.2 seconds to perform. Therefore the factor of determining the performance is within 0.2 seconds, how many available muscle motor units can be recruited for contraction, yet how much fast-twitch fibers in the body. as the result, an athlete lacking fast twitch fibers has better control of nervous system that recruited all the fast-twitch fibers in the body, the athlete tends to have superior performance in comparison to the athlete with less control of nervous system while having greater number of fast twitch fibers.[33]

From above, people can considerably increase their strength without increasing the size of their muscle, because the body becomes more efficient at muscle recruitment and firing synchronization.

"  

"  
My comment
1.  No discussion of how movements are initiated or motivated. 
2.  No mention of GABA or tonic inhibition.      



Motor learning (Wiki) 
    "Motor learning is a change, resulting from practice or a novel experience, in the capability for responding. It often involves improving the smoothness and accuracy of movements and is obviously necessary for complicated movements such as speaking, playing the piano, and climbing trees; but it is also important for calibrating simple movements like reflexes, as parameters of the body and environment change over time. Motor learning research often considers variables that contribute to motor program formation (i.e., underlying skilled motor behaviour), sensitivity of error-detection processes,[1][2] and strength of movement schemas (see motor program). Motor learning is "relatively permanent", as the capability to respond appropriately is acquired and retained. As a result, the temporary processes that affect behaviour during practice or experience should not be considered learning, but rather transient performance effects. As such, the main components underlying the behavioural approach to motor learning are structure of practice and back given. The former pertains to the manipulation of timing and organization of practice (potentially for different subtasks or variations of the task) for optimal information retention (also see varied practice), while the latter pertains to the influence of feedback on the preparation, anticipation, and guidance of movement.

Contents

Physiological approach

The cerebellum and basal ganglia are critical for motor learning. As a result of the universal need for properly calibrated movement, it is not surprising that the cerebellum and basal ganglia are widely conserved across vertebrates from fish to humans.[citation needed]

Through motor learning the human is capable of achieving very skilled behavior, and through repetitive training a degree of automaticity can be expected. And although this can be a refined process much has been learned from studies of simple behaviors. These behaviors include eyeblink conditioning, motor learning in the vestibulo-ocular reflex, and birdsong. Research on Aplysia californica, the sea slug, has yielded detailed knowledge of the cellular mechanisms of a simple form of learning.

An interesting type of motor learning occurs during operation of a brain-computer interface. For example, Mikhail Lebedev, Miguel Nicolelis and their colleagues recently demonstrated cortical plasticity that resulted in incorporation of an external actuator controlled through a brain-machine interface into the subject's neural representation.[15]

At a cellular level, motor learning manifests itself in the neurons of the motor cortex. Using single-cell recording techniques, Dr. Emilio Bizzi and his collaborators have shown the behavior of certain cells, known as "memory cells," can undergo lasting alteration with practice.

Motor learning is also accomplished on the musculoskeletal level. Each motor neuron in the body innervates one or more muscle cells, and together these cells form what is known as a motor unit. For a person to perform even the simplest motor task, the activity of thousands of these motor units must be coordinated. It appears that the body handles this challenge by organizing motor units into modules of units whose activity is correlated.[citation needed]


My comment
1.  No discussion of how movements are initiated or motivated.   
2.  This offers an explanation of how kinesthetic memories are established.  
3.  No mention of GABA or tonic inhibition. 



Motor skill (Wiki) 
    "A motor skill is an intentional movement involving a motor or muscular component, that must be learned and voluntarily produced to proficiently perform a goal-oriented task, according to Knapp, Newell, and Sparrow.

Contents

My comment
1.  No discussion of how movements are initiated or motivated.   
2.  No mention of GABA or tonic inhibition. 



Motor coordination (Wiki) 
    "Motor coordination is the combination of body movements created with the kinematic (such as spatial direction) and kinetic (force) parameters that result in intended actions. Motor coordination is achieved when subsequent parts of the same movement, or the movements of several limbs or body parts are combined in a manner that is well timed, smooth, and efficient with respect to the intended goal. This involves the integration of proprioceptive information detailing the position and movement of the musculoskeletal system with the neural processes in the brain and spinal cord which control, plan, and relay motor commands. The cerebellum plays a critical role in this neural control of movement and damage to this part of the brain or its connecting structures and pathways results in impairment of coordination, known as ataxia.

Contents

"  
My comment
1.  No discussion of how movements are initiated or motivated.   
2.  This 'motor coordination' might be thought of as kinesthetic memory. 


Sequence learning (Wiki) 
    "In cognitive psychology, sequence learning is inherent to human ability because it is an integrated part of conscious and nonconscious learning as well as activities. Sequences of information or sequences of actions are used in various everyday tasks: "from sequencing sounds in speech, to sequencing movements in typing or playing instruments, to sequencing actions in driving an automobile."[1] Sequence learning can be used to study skill acquisition and in studies of various groups ranging from neuropsychological patients to infants.[1] According to Ritter and Nerb, “The order in which material is presented can strongly influence what is learned, how fast performance increases, and sometimes even whether the material is learned at all.”[2] Sequence learning, more known and understood as a form of explicit learning, is now also being studied as a form of implicit learning as well as other forms of learning. Sequence learning can also be referred to as sequential behavior, behavior sequencing, and serial order in behavior.

Contents


My comment
1.  No discussion of how movements are initiated or motivated.   
2.  This 'sequence learning' might be thought of as part, but not all, of kinesthetic memory. 



Procedural knowledge (Wiki) 
    "Procedural knowledge, also known as imperative knowledge, is the knowledge exercised in the performance of some task. See below for the specific meaning of this term in cognitive psychology and intellectual property law.

Procedural knowledge, or implicit knowledge is different from other kinds of knowledge, such as declarative knowledge, in that it can be directly applied to a task. For instance, the procedural knowledge one uses to solve problems differs from the declarative knowledge one possesses about problem solving because this knowledge is formed by doing.[1]

In some legal systems, such procedural knowledge has been considered the intellectual property of a company, and can be transferred when that company is purchased.

One limitation of procedural knowledge is its job-dependence; thus it tends to be less general than declarative knowledge. For example, a computer expert might have knowledge about a computer algorithm in multiple languages, or in pseudo-code, whereas a Visual Basic programmer might only know about a specific implementation of that algorithm, written in Visual Basic. Thus the 'hands-on' expertise and experience of the Visual Basic programmer might be of commercial value only to Microsoft job-shops, for example.

One advantage of procedural knowledge is that it can involve more senses, such as hands-on experience, practice at solving problems, understanding of the limitations of a specific solution, etc. Thus procedural knowledge can frequently eclipse theory.

Contents

"  
My comment
1.  No discussion of how movements are initiated or motivated.   
2.  Kinesthetic memory might be thought of as part, but not all, of this 'procedural knowledge'.   



Searching PubMed for "central pattern generators" yielded 667 references: 
http://www.ncbi.nlm.nih.gov/pubmed/?term=central+pattern+generators  


Grillner

I noticed that many of the 667 Central Pattern Generator references listed "Grillner S" as one of the authors.  So I searched PubMed for "Grillner S".  Although Grillner doesn't mention "central pattern generators", he does talk about "locomotor networks", which are pretty much the same thing. 

Searching PubMed for "Grillner S" identified 349 References:   
http://www.ncbi.nlm.nih.gov/pubmed/?term=grillner+s 


2004   
89<349
Innate versus learned movements--a false dichotomy? 
http://www.ncbi.nlm.nih.gov/pubmed/14653146   
    "
It is argued that the nervous systems of vertebrates are equipped with a "motor infrastructure," which enables them to perform the full extent of the motor repertoire characteristic of their particular species. In the human, it extends from the networks/circuits underlying locomotion and feeding to sound production in speech and arm-hand-finger coordination."  



Searching PubMed for "motor programs" uncovered 5,045 references: 
https://www.ncbi.nlm.nih.gov/pubmed/?term=motor+programs  


Motor program (Wiki) 
    Abstract:   
    "A motor program is an abstract representation of movement that centrally organizes and controls the many degrees of freedom involved in performing an action.[1]p. 182 Signals transmitted through efferent and afferent pathways allow the central nervous system to anticipate, plan or guide movement. Evidence for the concept of motor programs include the following:[1]p. 182
  1. Processing of afferent information (feedback) is too slow for on-going regulation of rapid movements.
  2. Reaction time (time between “go” signal and movement initiation) increases with movement complexity, suggesting that movements are planned in advance.
  3. Movement is possible even without feedback from the moving limb.

This is not meant to underestimate the importance of feedback information, merely that another level of control beyond feedback is used:[1]

  1. Before the movement as information about initial position, or perhaps to tune the spinal apparatus.
  2. During the movement, when it is either “monitored” for the presence of error or used directly in the modulation of movements reflexively.
  3. After the movement to determine the success of the response and contribute to motor learning.

Contents

  • 1 Central organization
    • 1.1 Open and closed-loop theories
      • 1.1.1 Response-chaining hypothesis
      •     "The response-chaining, or reflex-chaining hypothesis, proposed by William James (1890),[2] was one of the earliest descriptions of movement control. This open-loop hypothesis postulated that movements required attention only for initiation of the first action.[1]p. 165 As such, each subsequent movement was thought to be automatically triggered by response-produced afferent information from the muscles. Although feedback is involved in this process, ongoing movements cannot be modified if there are unexpected changes in the environment; feedback is not compared to some internally generated reference value for error checking. "    

      • 1.1.2 Adams’ closed-loop theory
      •     "In contrast to the open-loop response-chaining hypothesis, Adams' closed-loop theory suggested that processing of afferent information was central in human motor control.[5] Adams’ closed-loop theory is based on basic motor learning research that focused on slow, graded, linear positioning tasks, which involved error detection and correction to meet goal demands. To learn a movement, a “motor program” consisting of two states of memory (i.e. memory trace and perceptual trace), is required. The memory trace (equivalent to recall memory in verbal learning) initiates the motor movement, chooses its initial direction and determines the earliest portions of the movement. Strengthening of the memory trace results from practice and feedback about movement outcome (see motor learning). In addition, the perceptual trace (similar to recognition memory in verbal tasks) is involved in guidance of the limb to the correct position along a trajectory. This is accomplished by comparing incoming feedback to the perceptual trace, which is formed from the sensory consequences of the limb being at the correct/incorrect endpoint in past experience. In the event of an error, the limb is adjusted until the movement is appropriate to the goal of the action. Importantly, the more accurate the movement, the more useful the perceptual trace that is collected and retained.

        Though this theory represented an important leap forward in motor learning research,[1] one weakness in Adams’ closed-loop theory was the requirement of 1-to-1 mapping between stored states (motor programs) and movements to be made. This presented an issue related to the storage capacity of the central nervous system; a vast array of movements would require equally large repository of motor programs. Additionally, this theory could not be used to explain how motor programs for novel movements were formed.   

      •   1.2 Schmidt’s schema theory   

      •     "Early motor program theories did not adequately account for evidence illustrating the influence of feedback for the modification of ongoing movement while providing a suitable explanation of motor programs storage or application in novel movement. Consequently, the notion of the generalized motor program (GMP) was developed.[1]p. 205 The GMP is thought to contain an abstract representation for a class of movements with invariant features pertaining to the order of events, the relative timing of events and the relative force with which events are produced. In order to determine how a particular movement should be performed, parameters such as overall movement duration, overall force of contractions and the muscles involved are specified to the GMP. This revision of the motor program concept allows many different movements to be produced with the same motor program as well as the production of novel movements by specifying new parameters.

    • Richard Schmidt (1975) proposed the schema theory for motor control,[6] suggesting in opposition to closed-loop theories, that a motor program containing general rules can be applied to different environmental or situational contexts via the involvement of open-loop control process and GMPs.[7]p. 32 In Schmidt’s theory, the schema (psychology) contains the generalized rules that generate the spatial and temporal muscle patterns to produce a specified movement.[7]p. 32 Therefore, when learning novel movements an individual may generate a new GMP based on the selection of parameters (reducing the novel movement problem), or refine an existing GMP (reducing the storage problem), depending on prior experience with movement and task context.

      According to Schmidt, four things are stored in memory after an individual generates a movement:[6]

    • The initial conditions of the movement, such as the proprioceptive information of the limbs and body.
    • The response specifications for the motor programs, which are the parameters used in the generalized motor program, such as speed and force.
    • The sensory consequences of the response, which contain information about how the movement felt, looked and sounded.
    • The outcome of that movement, which contains information of the actual outcome of the movement with knowledge of results (KR).

    This information is stored in components of the motor response schema, which include the recall schema and recognition schema. The recall and recognition schema are strongly associated, as they use the relationship between the initial condition and actual outcomes; however, they are not isomorphic.[6] They differ in that recall schema is used to select a specific response with the use of response specifications, whereas the recognition schema is used to evaluate the response with the sensory consequences. Throughout a movement, the recognition schema is compared to the expected sensory information (e.g., proprioceptive and extroceptive) from the ongoing movement to evaluate the efficiency of the response.[7]p. 32 An error signal is sent upon finalizing the movement, where the schema is then modified based on the sensory feedback and knowledge of results (see motor learning).

    The schema theory illustrates that motor learning consists of continuous processes that update the recall and recognition schemas with each movement that is made.[7]p. 33"       

    • 1.3 Multiple paired forward and inverse models
    •     "An alternate viewpoint on the organization and control of motor programs may be considered a computational process of selecting a motor command (i.e., the input) to achieve a desired sensory feedback (i.e., the output).[8] Selection of the motor command depends on many internal and external variables, such as the current state of the limb(s), orientation of the body and properties of the items in the environment with which the body will interact. Given the vast number of possible combinations of these variables, the motor control system must be able to provide an appropriate command for any given context. One strategy for selecting appropriate commands involves a modular approach; multiple controllers exist such that each controller is suitable for one or a small set of contexts. Based on an estimate of the current context, a controller is chosen to generate the appropriate motor command.

      This modular system can be used to describe both motor control and motor learning and requires adaptable internal forward and inverse models. Forward models describe the forward or causal relationship between system inputs, predicting sensory feedback that will occur. Inverse models (controllers) generate the motor command that will cause a desired change in state, given an environmental context. During motor learning, the forward and inverse models are paired and tightly coupled by a responsibility signal within modules. Using the forward model’s predictions and sensory contextual cues, responsibility signals indicate the degree to which each pair should be responsible for controlling current behavior."

    •   
  • 2 Impairment of motor programs
  • 3 See also
  • 4 References
  • 5 Further reading
  • 6 External links
My comment
    No mention of GABA or behavioral disinhibition.  Except for a brief mention of the cerebellum, no mention of neuroanatomy or endocrinology.     



My overall comment:     

There was no mention of   Behavioral Disinhibition   in any of the references.  The only mention of GABA was in the   5.1 Striatum and basal ganglia    section of the  "Procedural memory" reference. 




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