Motor Programs - Chap. 5 Flashcards
generalized motor program can account for what common observation
that movements can be varied along certain dimensions
-slower, faster, louder, softer etc.
what are degrees of freedom
the multiple ways for one to perform a movement to achieve the same goal
what is the degrees of freedom problem
since there are so many ways for one to performa a movement to acheive the same goal, it leaves us with the question of how the brian chooses a course of these actions among infinite ones
what is the important concept of a motor program
the prestructured set of movement commands that defines and shapes the movement
what kind of control mechanism is in some ways the opposite of the closed loop system
open-loop control
whta are the 2 parts that the basic open loop system consists of
an executive and effector
define open-loop system
type of control systmem in which the output has no influence or effect on the control action of the input signal
-no feedback for the ouput
how is a traffic light an example of an open loop system
there is a preset structure of timing and command that lets traffic move (when ligths change)
-this program can be updated and may be depending on time of day
-it is not entirely fixed but modifiable
-whenever the action of changing lights is being executed, it is bound to reset the commands
what are 5 aspects that needs to be programmed once you know which target one is going to
-which muscle to contract
-coordinated action
-what order needs to be activated in
-when
-for how long
with practice, a motor program can become what 4 thigns
-able to modulate reflexes
-variable error (how consistent)
-more precise
-stable for a longer period (can not practice for a while, come back and still be able to perform)
in the resonse programming stage, what are 4 things the CNS needs to organize before a movement can begin
- figure out degrees of freedom
-commands
-any postural adjustments
-modulate any reflex pathways
when it comes to degrees of freedom, 792 muslces x 100 joints = qhat
too many options
because there are too many degrees of freedom, how do we program movements
think in actions
-organize the degrees of freedom into a single unit rather than individually
-action = motor program
what are 5 commands a motor program will send to the muscles
-which muscles involved
-the order need to be activated
- the forces needed
-the relative timing
-the duration of each contraction
ultimately, in a motor program, sending commands to the muscles is to prepare what
patterns of neural activity
what are the phases in the step cycle
- swing phase
- stance phase
what is the reflex reversal phenomenon when it comes to the step cycle
when walking and there is an obstacle on the ground
-already in stance phse
-weight down on foot instead of withdrawing (still a reflex)
-helps get on to next leg faster and protects from buckling and falling
what hekps modulate the reflex reversal response
CPGs in the spinal cord
(central pattern generators)
what does a motor program consist of to do what (simple)
pattern neural activity that creates coordination and sends this information out to the effectors
what is the consensus on the existence of motor programs
not everyone agrees that they exist
what are 5 evidences that motor programs exist
-reaction time
-startle stimuli
-cases where sensory feedback removed
-what happens when humans attempt to stop
-muscle response patterns when movement is blocked
when an individual is performing a task and they knew what movement needed to be done what does the informaioto processing look liek
no response selection needed, jsut need to finish programming response
how is reaction time evidence for motor programs
study compared 3 conditions
1. simple finger lift
2. simple finger liftt and reach to slap ball pre
3. finger lift reach to slap ball and press button and grasp ball
(always simple reaction time)
-found that RT gets longer when response become more complex
**evidence because response programming staege is longer when more complex response to perform
how is the startle effect evidence for motor programming
no prep or response programming
-no reason that allowed stimulus to cause us to move faster
-able to speed up response
-regardless of if whole executive is bypassed or if everything is done faster
how are cases of sensory feedbakc being removed evidence for motor programming
when removed, we can still produce movement
-if theres no central motor program, this should cause us to not be able to move
in an open-loop control, it consists of what 2 main features used in closed loop control and what is is misisng
contains
-executive
-effector
missing
-feedbakc
-comparator mechanisms for determining system errors
describe the course of open loop control
-input given to exectuive level (defines what actions need to be taken)
-passes instructions to effector level (carries out instructions)
-onces actions completed, systems job is over until executive is activated again
what are 2 things that cannot be done in an open loop control and why
-not senstivie to whether or no the actions generated in the environemnet were effective in meeting the goal
-modifcations to the actions cannot be made while action is in progress
**no feedback
where are open loop systems most effective
in stable, predictable environments in which the need for modification is of commands are low
-closed environemnt
what type of movements seem to be controlled in an open loop fashion
ones that are rapid, brief, and forceful
movement execution is not actually controlled by the cosncious decision-making stages, so it is carried out by what
a system that is not under direct conscious control
-motor program (determines which muscles to contract, in what order, when and for how long)
practice, which leads to learning skilled actions is thought of as what in relation to motor programs
building enw, more stable, more precise, or longer operating motor programs (or some combinations of these)
once a motor program is learned where is it stored
in long-term memory and must be retrieved and prepared for initation during the response programming stage
in the conceptual model, if the mvoement of a task i very sloe or of long duration, what system dominates
by the feedback processes
in the conceptual model, if the movement of a task is very fast or brief what system tends to dominate
open loop portions
in RT experiments, the duration of the RT delay was what when more info needed to be processed and when it was not natural
slowed
in henry and rogers experiment with reaction complextiy effect, they found that simple RT was eleveated with increases in what
the complexity of the movement to be performed AFTER the response was initiated
why does the complexty of the movement ot be perforemd increase RT
more time is required to organize the motor system before the initiaiton of the action
-this organization occurs in the movement programming stage
how does the fact that complex movement increases RT show evidence of motor programs
because at least some of the action is organized in advance
-just as a motor program theory would expect
how is the startle effect evidence for motor programming
when a stimulus startles an individual (like a loud noise), their response is the same as it would be normally, however, it happens much faster
-idea is that the executive has prepared a motor program in advance of the stimulus to respond
-not sure which, but the startle effect could possibly speed up the executive’s processing
what is deafferentation
surgical technique that involves utting an animals afferent nerve bundles where they enter the cord so CNS no longer can retreicve info from some protion of the periphery
in deafferentation, how are motor pathways not affected by the procedure
the info about motor activity passes through the ventral side of the cord (uncut)
what are sensory neuropathy patients
individuals who have lost much of their sensory feedback
- are still able to perform quite well in their environments, as long as visual info is available
is sensory info from the moving limb critical for movement production
no,
deafferentation
sensory neuropathy patients
how are the theories of movement control generally incorrect
because they say that sensory info is required when in reality its not always the case
how is deafferentation evidence for motor programs
supports the idea that movemnts can be organized centrally in motor programs
the idea of motor programs is similiar to that of what and describe
central pattern generator
-neuronal circuits that produce motor patterns
how do central pattern generators work
its established in the brainstem or spinal cord
-when its initiated, sometines by a command neuron - produces rhythmic, oscillating commands to musculature to define a squence of right-left-right activities
how is it known that central pattern generator command organization is truly central in origin
these commands occur even if the sensory nerves are
what is the main difference between central pattern generators and motor program
MOTOR PROGRAM
-involves learned activities that are centrally controlled
CPG
-involves more genetically defined actiities (locomotion, chewing, breathing)
what method is most frequently used to study action inhibition
stop-signal paradigm
how is inhibiting actions evidence for motor programs
motor program is released that is responsible for initiating the action in tasks and that serves to carry out the entire action unless a second stop-signal program is initiated in time stop its completion
what type of muscle pattern is typically of quick movments
triple burst
-agonsit-antagonist-agonist
how are muscle response patterns evidence for motor programs
in experiment, the antagonist (biceps) muscle even contracted at all when the movement was blcoked and it contracted at the same time as in normal movements
-support idea that the movement activities are organized in advance carry out unmodified sensory info
what are 4 major roles of open-loop organizations
-to define and issue commands to musculature
-organize degrees of freedom into single unit
-specify and initiate postural adjustments
-module reflex pathways
whhat are storage problems
how/where do humans store the nearly countless number of motor programs needed for future
what are novelty programs
how do performers produce truly novel behaviour such as performing a varient of tennis swing never done previously
-the program for such an action cannot be represented in an already stored motor program
what idea emerged when they were trying to keep appealing aprts of motor program but aslo account for the storage and novelty problems
the generalized motor program
what is the generalized motor program in stored memeory
thought to be adjusted at the time of movement execution
-allowing the action to be hcanged slightly to meet the current environement demands
what are invariant features
things that define
-features that make the pattern appear the same, time after time
what are parameters
details
-fast run, long run, slow
-modifiable features invarient features
the word paramter comes from mathematics and represents wha
numerical values in an equation which do not change hte form of the equation
Y = a + bX
-a and b are parameters, Y and X are related to each other in same way for any value of a and b
-the unique performance that occurs when certain parameters are changed does not ater the inariant characteristics - only how the general motor program is expressed at a given time
what stage ais a general motor program chosen during
response selfection stage
-retireved rfom long-term memory
-and parameters are added (parameterized) in response programming
what are 3 aspects of invarient features
-relative timing or rhythm
-relative forces
-order muscles are activated
**these 3 things create coordination
when changing from walking to running, what invariant features occur
change relative timing and forces
relative timing produced by a performer can be thought of as what and has to do with what 2 characterstics
a kind of fingerprint, unique to a particular movement class
-spatial and temporal
what are 3 asepcts of parameters
-movement time
-movement amplitude
-specific effectors
what is the stereo system analogy
the phonograph record is the GMp, speaker are the muscles and limbs
-record contains all of the features and is stored on it, and many diff. records to chose from (like how we have many motor progras)
what feature of GMP is march vs. waltz
invariant
-change relevant timing
what feature of GMP is slow vs fast
parameter
-movement time
what feature of GMP is pen on paper vs. toe in sand
paramter
-changed effector
what feature of GMP is throwing vs kicking
it depends
-muscle order different
LITTLE KID
-using basic patterns to move object in space
EXPERT
patterns become seperated
***with practoce gets own motor program creatin a clear and obvious pathway
what are 3 ways that make motor control theries differ
-role and function of the CNS
-influence of environment features
-how the environment and NS interact
info processing, dynamical system and general motor program can be seen as what
a continuum
-info processing and dynamical system on central processing side and general motor prgroam on environmental influence
in the motor control theory continuum, what type of tasks are mostly found in info processing and dynamical system
discrete and serial skills
in the motor control theory continuum, what type of tasks are mostly found in general motor program
continuous taskthe ge
the general motor program theory is helpfulf for what
explaining how we can perform rapid actions and how we learn movement sequences
what is not believed in in dynamical systems
the executive
what does the dynamical system belive in
self organization
-will organize into the most stable behaviour - pattern of coordination
what motor control theory solves the degrees of freedom problem
what is inphase
when limbs move in same pattern
what is antiphase
limbs move opposite, mirrored pattern
what happens when one is doing antiphase really fast
turns into inphase because it is the most stable pattern
-dont have to consciously think to switch from one to the other
coordination involved what kind of relationships
relative spatial and temporal between limbs and within limbs
stable coordination happens cause of complex dynamics between what 3 things
-NS
-environement
-task/limbs
