EXS 313 Exam 2 Flashcards
open-loop control
desired state (feedforward)
executive system (brain, information processing, decision-making)
effector system (spinal cord, limbs, nerves, movement, implementation)
actual state
a way to control fast movements that are produced without the use of movement produced feedback for adjustment during movement
closed-loop control
desired state (feedforward)
executive system (brain, information processing, decision-making)
expected state (goes to the comparator)
effector system (spinal cord, limbs, nerves, movement, implementation)
actual state (goes to the comparator)
comparator (evaluate/compare if our actual action matched our desired action)
error (if there is an error score of 0, you continue without changing commands)
this model relies on feedback
a process of movement control that usually pertains to slow, continuous movements or automatic movement adjustments (reflexes)
point-of-no-return
the point in a skill where you can no longer make adjustments or corrections due to time constraints
deafferentation research findings
the surgical procedure to severe a bundle of nerves to prevent nerve impulses from reaching the spinal cord (no sensory feedback)
- fast actions and locomotion were fine
- tasks requiring closed-loop control were not possible (no fine motor tasks)
finding: certain motions are pre-programmed, so we don’t need sensory feedback (similar to open-loop control)
reflexes
rapid movements
example) knee-jerk response when the patella tendon is stimulated (M1 reflex)
M1 reflexes: is low level and does not involve voluntary control
30-50 ms (very fast)
M2 reflexes: slightly more voluntary and longer
50-80 ms
reflexes in a closed loop model
a process of movement control that usually pertains to slow, continuous movements or automatic movement adjustments
inherent feedback
the feedback that comes naturally
example) visually seeing the error
augmented feedback
the feedback that is given by an outside source
example) coach, newspaper article, PT clinic device, stopwatch, video replay
optical array
the ray of light reflected by the objects in your vision, hit the eyes at certain angles
- light is bouncing off of all objects in your visual field (environment), making them visible to you
optical flow
change in light information (change in array) as you move through the environment, “flow of light” across the retina
important information: time until contact, trajectory
dorsal vision system
entire visual field, control of movement, nonconscious, good in low light, track motion, fast
processed at motor intent level
ventral vision system
focal system
central field only, ID objected, conscious, degraded by low light, slow
processed as exteroceptive feedback
quiet eye movements
duration is often related to skill/performance
longer quiet eye = more skillful
saccadic eye movements
discrete, fast, quick, information received during fixations, quiet eye; jumping tracking
example) a car drives by really fast, but you were able to read the license plate during a saccade/fixation
smooth pursuit eye movement
slow, precise; pick up details on slow-moving or still objects
smooth tracking
generalized motor program theory
a program that governs a class of similar movements (a basic structure)
pulls parameters and adjusts the time of movement to meet environmental demands
invariant features
make the movement appear the same, time after time
- order of movement components
- relative timing
- temporal structure/rhythm
parameters
the way a movement is executed (variations)
example) writing slow or fast, large or small
novelty problem
we never repeat the same movement twice
storage problem
too many things to remember
temporal accuracy
timing
spatial accuracy
location (space)
index of difficulty
defines the difficulty of targets based on a combination of amplitude and width
single motor program view
one motor program used, flow through the bottleneck quickly
