Lec 5-1 Flashcards
When moving both limbs to two separate targets, what trend can be seen?
Why?
Movements are synchronized
Even if targets differ in distance, width etc., both limbs start and stop movement at same time.
The easier target does not get finished quicker.
This is because it decreases the individual components needed to coordinate in the body (only have to control one movement as opposed to two separate movements)
what happens if you introduce a hurtle to only on limb during bimanual
Both limbs alter course, limb with no hurtle still alters path even though they don’t need to
Coordination vs coordination dynamics
Coordination - ability to organize and control movements.
- focus on outcome of how movements are organized.
Coordination dynamics - sensorimotor constraints, tendency towards synchrony, discusses Von Holst’s principles
characterization of coordination: spatial, temporal, and functional patterns of organization
- focusses on process, mechanisms that allow coordination to happen and adapt
Describe the proposed coordinative structure
idea that brain organize groupings of muscles (coordinative structures) that act as a single unit for two handed tasks.
Describe Von Holst experiment animals, and results
- Took a type of of fish that only uses fins to swim, would block fin and observe the other fin increasing tempo to account for this block
- centipede, would remove legs and observe the changing locomotive patterns from leg amounts.
Difference between absolute coordination and relative coordination
Absolute - movements between limbs line up (peaks and valleys match when looking at limb movements)
Relative - some movements line up (like metronomes out of sync, sometimes line up)
define maintenance tendency and magnet effect in coordination dynamics
Maint tend - limb prefers to stay at its own tempo
Mag effect - limb is attracted to move at another limbs tempo
Name the Von Holst’s coordination rules (3)
- Few patterns can be easily performed and are distinguished by stability
- stable patterns are maintained until some limiting condition is reached then can transition to another pattern
- You always tend towards patterns of increasing stability, not the other way around.
Describe in phase and anti-phase pattern transitions in limbs
Relate to egocentric and allocentric
which starts to happen at faster speeds
Egocentric
- For same limbs e.g. hands.
- In-phase = same muscles (homologous) activated at same time, (0 degrees) anti-phase = opposite muscles activated (windshield wipers 180 degrees)
Allocentric
- Refers to direction of movement in different limbs (e.g. hand and foot)
- In-phase = same direction of movement (up/up), anti-phase = opposite directions (up/down)
In-phase for each principle is always easier at higher speeds.
difference between egocentric/allocentric
Egocentric - is about the homologous muscles from same limbs (e.g. hands) working
in phase = same muscles used
Allocentric - is about direction of movement being the same between different limbs (if pronate or supinate hand, muscle activation change, but direction stay the same for hand/foot coordination)
in-phase = same direction of movement
How was the H reflex and EMG used to test whether egocentric or allocentric principle was true
- Used H-reflex to check the excitability of the muscles at certain points of the movement
- Used EMG to see when muscles were being activated
- by comparing them, they could see when certain muscles are most excitable in correlation to which muscles were firing.
- Found that excitability and muscle activation lined up better when following in phase movements for egocentric and allocentric principles.
what happened in the visual synchrony experiment when they took people and sat them next to each other to make movements
participants sat beside each other and had to either move their legs in the same direction or different directions, also found it easier to move legs in same direction rather than opposite directions (in-phase easier than anti-phase
