KPE261
What are the two main functions of the premotor cortex?
- Movement execution and initiation of fine motor skills
- Learning consolidation
What does the Premotor Cortex do?
- Plans and organizes movements based on sensory cues
- the integration of tactile/visual feedback to form a motor response.
What is the SMA responsible for?
- Chunking movements/steps into sequences.
- Chunking or grouping makes info easier to remember
- Response times are usually longer at chunk points.
How does TMS effect pre-SMA functioning?
- If you stimulate the SMA outside a chunk point, the response time is the same.
- If you stimulate the SMA during a chunk point, the 1st movement RT is slower but the chunk point as a whole is recalled faster.
What movements are controlled by the Basal Ganglia?
- Internal timing (keeping time to a song)
- Reward Based Learning via vigor and motivation (dopamine)
Bradykinesia, Akinesia, Tremors and Apathy are all variants of this neurological disease that affect the Basal Ganglia.
- Parkinson's Disease ( reduction in dopamine )
What is the role of the cerebellum?
- Optimizes Performance: compares the predicted to actual consequences to movements.
- Error detection and correction
A lesion to the cerebellum will cause what?
- Doesn't inhibit movement
- May cause problems with coordination resulting in clumsy movements
Ascending Sensory Pathways connect and carry what?
- Connect the spinal cord to the sensory cortex and cerebellum.
- Carry info from sensory receptors
This system transmits information about proprioception touch and pressure.
The Dorsal System
This system transmits info about pain, temperature and pressure.
The Anterolateral System
This tract transmits proprioceptive info to the cerebellum.
The Spinocerebellar Tract
List 3 facts about descending motor pathways
- Connect neurons in M1 to the spinal cord.
- Most fibres cross in the medulla and therefore you have contralateral control of movements.
- is involved in fine motor skill performance
Extrapyramidal tracts connect neurons in the brainstem to the spinal cord. What movement control are they also involved in?
- Postural and proximal limb (shoulder/trunk) control
Where do each of the tracts synapse?
- Descending connects to the ventral horn
- Ascending synapse in the dorsal horn.
What is the Hennmann size principle?
- addresses motor recruitment
- Smallest fibers are recruited first then larger ones in size are added in addition to them.
Define "Coordination"
- The organized relationship between body parts at a specific point in time during skill performance.
- can be constrained by the environment. Patterns of body parts are relative to patterns of environmental objects and events.
Who proposed the DF Problem? What are their two arguments for this to be an issue when talking about coordination and skill acquisition?
- Nicolai Berstein
- There are too many independent aspects of motion and the ways that they can interact.
- There are also many ways to perform a skill = REDUNCANCY
Motor programming is one of the major coordinators of movement. What does it do?
- It processes information
- deals with CNS memory-based mechanisms that control movement
- set movement commands that define movements like a computer.
Dynamical Systems is the other major motor control theory. What is the emphasis of this system?
- Emphasis on the role of information in the environment. and the mechanical properties of body and limbs
What is an open loop control system?
- a system in which all the info required to run a movement/system is already present.
- does not use feedback.
- Used for fast ballistic movements
- effective if environment is stable and predictable (controlled)
What is a closed loop system?
- Control center initiates instructions which can be updated.
- Execution and completion is based on feedback.
- used for larger slow movements.
The Generalized Motor Program (GMP) is also known as what theory and states...
AKA "Schmidt's Schema Theory"
A motor program that defines a pattern of movement/class of actions rather than a specific movement.
Can be modified to produce variations of the pattern.
What are the two main characteristics of the GMP? (Give examples of each type)
1. Invariant (fixed, unique) features - do not change between performances; Ex. relative timing and relative sequencing
2. Parameters (Flexible Features) - add onto a GMP which can vary between actions. Ex. Movement time/duration, limbs and muscles used.
Why is sensory information important?
It gives feedback to the body about external environments in order to coordinate movement.
What are the photoreceptors involved in visual processing?
Cones and Rods
What is the main role of vision in motor control?
To prepare for tasks based on vision