Lecture 22: Locomotion Flashcards Preview

Neural Control of Movement > Lecture 22: Locomotion > Flashcards

Flashcards in Lecture 22: Locomotion Deck (44):
1

Locomotion

an activity leading to a change in the location of the body in external space.

2

Examples of locomotion

walking, running, hopping, swimming, flying, crawling, etc.

3

Important characteristics of locomotion

-velocity
-stride length
-relation between the support and swing phases
-relative timing of the extremities (gait)

4

Two different views of Locomotion

1. Motor Programming
2. Dynamic Systems

5

Motor Programming

Central Pattern Generator: hypothetical neural structure that generates a neural activity, activity is transformed into rhythmic muscle activity, leading to rhythmic behavior

6

Dynamic Systems

rhythmicity of locomotion is caused by interaction of neural activity and the periphery

7

Early Views of Locomotion

1. Sherrington
2. Brown

8

Sherrington

-Locomotion was a pattern produced by alternating reflex responses.
-Voluntary movement is a result of modulating reflexes

9

Brown

Rhythmic motor pattern of locomotion was produced by a special neural network(CPG) that could produce activity even in the absence of reflexes

10

A CPG is

a hypothetical structure in the central nervous system that can generate patterned (rhythmical) activity

11

CPG can be driven by _______ as well as by peripheral information

"Higher" centers

-Both sources of information can lead to gait changes

12

CPG involves ______ types of cells.

three

13

CPG: Cells of two types act on each other and ________.

suppress each other's activity.

14

CPG: Cells either fatigue quickly or turn off after a brief period of activity, allowing _____.

the other group to be released from inhibition and take over.

Cycle continues until an external influence turns off both groups of cells.

15

Neurons of the 3rd group provide ___________.

input that can both excite and suppress the cells of the 1st two groups

16

Problems w/CPG: ______ higher center

Undefined

17

Problems w/CPG: ______ input could change the pattern of gait activity

Peripheral

18

Problems w/CPG: Difficult to determine if changes in ____ are produced by higher center or peripheral input.

gait

19

Problems w/CPG: Many important variable lack _____.

a good definition

20

Problems w/CPG: This drove the development of _____.

dynamic systems approach

21

Stimulating _____ of cats led to rhythmic moments of the cat's limbs

reticular formation

22

Different levels of stimulation could _________ locomotion.

slow down or speed up

23

Locomotor Strip is in the ____.

upper cervical region of the spinal cord

24

________ of certain brain areas can induce locomotion

Electrical Stimulation

25

______ changes with the strength of the stimulation.

Gait

26

Locomotion and gait changed can also be induced by ______.

treadmill motion and by intraspinal drugs

27

________ locomotion can be see.

Fictive

28

Graham Brown v. Sherrington: The spinal is likely to contain one, two, to even four _________.

Central Pattern Generators

29

Graham Brown v. Sherrington: A CPG can be driven by _____.

descending and ascending signals.

30

Graham Brown v. Sherrington: It does not necessarily require _____.

either signal

31

Graham Brown v. Sherrington: It can produce ____.

different gaits

32

Dynamic Systems Approach is a system for:

movement production, including the central neural structures, effectors and the connections with the CNS, and the environmental forces and sources of sensory information, can be modeled with complex, non-linear equations.

33

______ better explains issues of stability (particularly in M/L direction)

Dynamic Systems Approach

34

Dynamic Systems Approach succeeds in describing ______.

inter-limb and inter-joint coordination

35

DSA: The equations developed by this approach can describe these rather ____.

complex changes in behavior.

36

Motor Programming lacks ___.

coordination, all details of coordination are delegated by the ultimate controller

37

Dynamic Systems: coordination can emerge without supreme problem solved, but it lacks_____.

control

38

What happen when there is a combination of motor programming and dynamic systems?

All elements are linked and there is an upper neural structure that can send descending signals.

39

In M/L direction, COP shifts _______.

towards the stepping foot and then shifts back toward supporting foot.

40

In A/P direction, COP shifts ______.

backward

41

Corrective stumbling reaction occurs during _______.

locomotion

42

Corrective stumbling reaction can be induced by _____.

a mechanical stimulus to the foot.

43

Corrective stumbling reaction represents a _______.

complex pattern of EMG changes

44

Corrective stumbling leads to _____.

a quick step over the obstacle.