Motor Learning: Doyon Model & Neurological Impact

• Doyon model: motor sequence learning is mediated through the basal ganglia and corte, motor adaptation is mediated through the cerebellum and cortex

Cerebellar Stroke Impact

• Early learning for motor sequence learning and motor adaptation may be slowed
• Consolidation and automatization of motor sequence learning remain intact
• Motor adaptation can be disrupted
• Early adaptations may be made, but gains may not be retained
• The diversification stage may be disrupted if taking into account Gentile's model

Parkinson's Disease (Basal Ganglia Damage) Impact

• Early learning for motor sequence learning and adaptation might be slowed
• Consolidation and automatization of motor adaptation remain intact
• Motor sequence learning can be disrupted
• Early sequence learning may be observed, but the gains will not be retained
• Fixation can be a struggle if you take Gentile's model into account

Speed-Accuracy Trade-Off

• The speed a skill is done at is influenced by the demands for movement accuracy
• Increasing speed decreases accuracy, and vice versa

Fitts' Law

• Human performance law predicts movement time for an action that requires both speed and accuracy
• An individual should move as quickly and accurately as possible to a target

Two Motor Control Processes

• Existence of two motor control processes may explain speed-accuracy trade-off
• Open-loop/feed-forward involves no feedback
• Closed-loop/feedback involves sensory feedback

Bimanual Coordination

• Many skills require the coordination of two limbs, or bimanual coordination
• The central nervous system likes symmetric arm movements
• Reorganization or learning is required for asymmetric tasks
• Asymmetric tasks are harder than symmetric tasks
• Organization of interhemispheric connections is related to the organization of tasks

Motor Control Theories

• They offer explanations of how movements become uncoupled or asymmetric
• Generalized Motor Program (GMP) Theory says that new GMPs need to develop, either for each limb or one that is specific to the asymmetric movement
• Dynamical Systems Theory: symmetric movement is an attractor state
• Practice can destabilize it, and a new attractor state emerges as the new pattern stabilizes

Reaction Time

• This is the most common index of action/movement preparation
• Reaction time gets faster as the number of choices decreases
• Reaction time gets faster as predictability increases
• Reaction time gets faster as S-R compatibility increases
• Reaction time gets slower as movement complexity increases
• Reaction time gets slower as movement accuracy demands increase
• Reaction time is slower for a second stimulus that occurs while reacting to the first stimulus

Performer Characteristics

• Alertness impacts reaction time
• Vigilance tasks require long-term alertness, like a goalie or outfielder
• Attentional focus and practice or expertise are key

CNS Responsibilities

• Perceptual/cognitive processing is key
• Muscle fibre firing
• Postural preparation
• Limb movement
• Rhythmicity and object control parameters

Attention

• Attention is the ability to direct the perceptual, cognitive, and motor activities associated with performing skills
• It involves cognitive effort

Limited Processing

• The central nervous system has a limited ability to process information

Central Resource Theory

• There is one central pool of attentional resources that all activities draw from
• Resource allocation depends on arousal and task demands

Multiple Resource Theory

• Several attentional resource pools exist
• Successful multi-task performance depends on whether attention demands are directed to similar or different resource pools

Kahneman's Model

• Its factors can impact your performance of a motor skill
• Arousal: more likely to drop nails if very tired
• Task demands: within capacity, more likely to make error if talking too
• Enduring dispositions (involuntary attention): more likely to miss nail if a dog barks
• Momentary intentions: if I choose to ignore people talking to me, less likely to make a hammering error

Attentional Focus Allocation

• Attentional focus helps to allocate attentional resources
• Use narrow, broad, internal, or external focuses
• Many tasks require attentional switching

Attention Quantification

• Attention can be quantified in many ways
• Dual tasking leads to performance outcome
• EEG leads to performance production
• Eye tracking leads to performance production

Memory

• Memory is the capacity of organisms to benefit from past experiences
• Memory is comprised of two functional systems
  • Working memory
  • Long-term memory
• Memory stores two distinct types of information
  • Declarative (Explicit) Memory
  • Procedural (Implicit) Memory

Memory at Soccer Practice Example

• You look at the field and assess the environment, and you use working memory to temporarily store the information
• Interface that info with stored information to recognize that you are at a soccer field
• Recall previous instruction (e.g., cues, technique)
• When kicking the soccer ball, retrieving the appropriate motor program and schema from long-term memory

Causes of Forgetting

• Trace Decay: memories deteriorate over time if not used
• Proactive Interference: information presented before what is to be remembered can disrupt storage
• Retroactive interference: information presented after what is to be remembered can disrupt storage

Strategies to Remember Motor Skills

• Use movement meaningfulness, with visual metaphoric imagery and verbal cues
• Have intention to remember
• Use subjective chunks of i

Types of Motor Learning

• Motor sequence learning: acquisition of sequential movements into a well-articulated behaviour
• Motor adaptation: compensate for environmental changes

Motor Sequence Learning Characteristics

• Tasks involve the serial reaction time task
• Chunking fuses a series of elements into a single unit
• Co-articulation sees that adjacent movement elements influence each other
• Note that it's easiest to find examples with serial movement tasks

Motor Learning Truth

• It is thought that basal ganglia is required for chunking of motor sequences

Types of Motor Adaptation

• Force field reaching tasks, split-belt treadmill task, and visuomotor adaptation tasks are common research paradigms used to study motor adaptatic
• When the novel conditions (force, split-belt speeds, goggles) are introduced, individuals initially make large errors, and then they adapt
• Removing the novel condition sees errors occur in the opposite direction, which is called after-effect
• Movement slowly readjusts to regular conditions, going through de-adaptation

Performance vs Motor Learning

• Learning is a relatively permanent change in capacity to perform a motor skill, and performance is the current skill
• Performance involves observable behavior and execution of a skill at a specific time and in a specific situation
• Learning cannot be directly observed, and must be inferred by observing performance

Assessing Learning

• Collect lots of data points and plot performance curves
• Perform retention tests to determine permanence of the skill learning
• Perform transfer tests to determine generalizability/adaptability of the skill
• Perform dual-task tests to measure the level of attention required to perform the skill

Definition of Learning

• Learning is relatively permanent

Broad Stages of Motor Learning

• Fitts & Posner Model: cognitive stage, associative stage, and autonomous stage, they overlap
• Gentile's Two-stage Model: focuses on impact movements, transfer improves consistency
• Memory Formation Model: encoding, consolidation, and retrieval through memory trace

Inferring Learning

• Progression can be inferred through the stages of learning by observing performance
• Look at rate of improvement, limb segment coordination, muscle activation patterns,visual attention, conscious attention, and error detection or correction

Neural Basis of Motor Learning

• Associative/Premotor Sensorimotor Network: prefrontal cortex, posterior parietal cortex, premotor area, cerebellar cortex, and caudate - BG
• Areas active throughout all stages include supplementary motor area (SMA), primary motor cortex (M1), cerebellar nuclei, and putamen - BG

Cerebellar Cortex and Nuclei

• Purkinje cells in cerebellar cortex provide an error signal and inhibit tonic excitatory drive to M1
• In early learning, many errors are made, so Purkinje cells in cerebellar cortex are active
• Fewer errors made in later learning, so cerebellar nuclei drive to M1 increased