Perception and Action Development Flashcards
Describe Gibson (1966) Bottom-up theory
perception involves innate mechanisms forged by evolution and that no learning is required
describe Gregory (1970) Top-Down theory
perceiving the world around us by drawing on our previous experiences to interpret new information
Gibson (1966) argues that perception is _
direct
- there is enough info in our environment to make sense of it in a direct way
- ‘ecological theory’ and affordances
describe the bottom-up process
raw sensory info, direct perception (constant perception-action loops)
Gibson’s Theory of perception - why doesn’t the story stop there?
- there is strong evidence to show that the brain and long term memory can influence perception
- in this case, it could be said that Gregory’s theory is far more plausible
Gregory (1970) suggests that info from our environment can be _
ambiguous, so to interpret it, we require knowledge from our past experiences
- our brain ‘fills in any missing pieces’ from our senses to make it make sense
- we are actively constructing our perception of reality
with gregory’s theory, highly ‘unlikely’ objects tend to be mistaken for_
likely objects
- ex. charlie chaplin head, hollow on other side but looked like face with nose pointed out
describe the necker cube (gregory’s theory of perception)
- stare at the crosses on the cube
- the cube orientations can suddenly change or flip
- it becomes unstableand a single physicxal pattern can produce 2 perceptions
- gregory argues that this object can flip because the brain develops 2 equally plausible hypotheses and is unable to decide between them
*1 image = 2 perceptions
summary of theories of perception:
- neither theories of perception seem capable of explaining all of perception, all of the time
- gibson’s theory lacks the ability to explain illusions
- gregory’s theory is primarily based on rare situations or experiences
What did Held and Hein (1963) study? (self produced locomotion)
- studied early motor activity in kittens
- researchers restricted the moment of some newborn kittens and permitted others to move
- wanted to keep their visual experience identical
Describe Held and Hein’s study in more detail
- kitty merry go round
- harnessed but could walk (active kitten)
- restricted and solely riding (passive kitten)
- both had equal perceptions
describe passive kittens
later failed to accurately judge depths and failed to exhibit paw placing or eye blinking when an object approached
- this demonstrates that self-produced movement is related to the development of behaviour depending on visual perception
what can the Held and Hein study tell us?
deprivation can put people at risk of deficient perceptual development
describe the role of action in perception
- developmentalists suspect that movement is important to perceptual develoopment
- movement is necessary for the coupling, or linking of perception and movement
why are perceptual-motor activities important?
they give children experience in performing skills based on perceptual info
name a great example of perception-action coupling
a musician’s brain is an excellent example of perception-action coupling because movements and intended sounds become strongly associated after long-term musical practice
what examples did claire use on how perception and action are coupled in everyday life?
cooking food, driving, playing music, knitting, golf
different surfaces require different _
movements
ex. shag carpet vs ice
how does locomotor experience influence infants actions when presented with different surface? describe what Gibson et al (1987) did
rigid surface (cloth over plywood)
deforming surface (cloth over waterbed)
- crawlers and walkers were presented with each surface
- all infants transversed the surfaces, but the walkers hesitated to cross the deforming surface
- they first stopped to examine the surface through vision and touch, and eventually crossed by crawling
- crawlers didn’t have a preference of materials
- but the walkers chose rigid
researchers have also found walkers to be more _ than crawlers to slopes
sensitive
- crawlers, less locomotor experience = will almost always attempt a slope (even if it is too steep for them)
- walkers will explore by patting the surface with their hands, or rocking back and forth on their ankles, most will descend backwards crawling down a slope over walking
how does locomotor experience affect judgements?
leads infants to make better judgements and avoid risky behaviours beyond their abilities
- through movement, infants generate perceptual info about their bodies and the environment
- these exploratory movements allow infants to calibrate environmental parameters and to start to perceive affordances
describe infant tool use (perception of affordances)
- through trial and error, infants are detecting affordances
- early movements may be building blocks for later tool use (banging objects become tuned for later percussion tool use)
- the ability to reach, grasp, control and bang objects provide the infant with the opportunity to detect affordances
define body scale
a person’s size relative to the environment
describe body scales
- body scales change over the lifespan
- scaling of sports equipment and environments allows people of various sizes to perform similar movements
give an example of scaling of sports equipment to ppl of various sizes
ex. if a child cannot swing a bat, or a heavy adult tennis racket with one hand, the child cannot use adult technique in the sport
- the large racket does not afford an adult style of movement
- either the racket must be scaled down, or the child could try using 2 hands
define balance
an individual’s ability to maintain their lineof gravity within their base of support
define postural control
the act of maintaining, achieving, or restoring a state of balance during any posture or activity
define perturbations to balance
sudden unexpected outside force to our stability
describe perturbations to balance
- dynamic balance strategies require feedforward body control (ie. anticipatory postural adjustments)
- perturbations to balance require fast motor responses to maintain stability
ex. poke with stick
how are perturbations to balance researched?
moving platform
- treadmill split on left and right
describe balance in younger adults
- younger adults on a moveable platform use ankle muscles to regain balance after small, slow perturbations
- they will also use hip strategies to regain balance after larger, faster perturbations
describe balance in older adults
- often take longer to initiate a response to a perturbation
- loss of strength, arthritic conditions in joints, slower nerve conduction speed
- balance can improve with practice responding to perturbations
- exercise programs that stress strength and balance can help reduce falls
describe ‘assessing balance’
- we can observe responses on a force plate, when balance is perturbed
- observation can involve electromyography (EMG) : timing of perturbation vs onset of activation
when it comes to stationary balance, is postural sway a good or bad thing?
- certainly, being able to stand still is a good sign of postural control
- but is postural sway necessarily a bad thing?
postural sway = unconscious, small movements that happen around the body’s center of gravity in order to maintain balance. It is your body’s natural adaptation to changing stimuli
describe postural sway in older adults
- where we start to have concerns is with older adults and if those small corrections aren’t happening, or aren’t happening fast enough
- falls are the leading cause of injury-related hospitalizations in Canadian seniors (Public Health Agency of Canada, 2014)
What did the graphs show - postural sway in older adults*
wider blob on graph, more variablility/sway
in the activity associated with fall-related injury infographic, what activities accounted for 4% of falls (each)?
- walking on any other surface
- engaged in other sport or physical activity
- other (includes skating, skiing & snowboarding)
in the activity associated with fall-related injury infographic, what activities accounted for 5% of falls (each) ?
- from elevated position
- from furniture/rising from furniture
in the activity associated with fall-related injury infographic, what activity accounts for 8% of falls?
due to health problems
in the activity associated with fall-related injury infographic, what activity accounts for 13% of falls?
up or down stairs/steps
in the activity associated with fall-related injury infographic, what activity accounts for 16% of falls?
walking on snow or ice
in the activity associated with fall-related injury infographic, what activity accounts for 45% of falls?
walking on any other surface
list the % of fall-related hospitalizations by place of occurance
50% - home
17% residential institution
0% industrial and construction
0% sports and athletic area
7% school, other institution, public area
3% street and highway
2% trade and service area
2% other specified place
0% farm
19% unspecified place
define focus of attention (F0A)
internal or external event to which attention is directed
define internal focus
directed toward components of the body movement
- learner will be consciously aware of how they are performing
give an exampel of an internal cue
focus on spreading your toes and applying even pressure on the ground
define external focus and provide an external cue
concentrating outside of body
- on the effects of one’s actions
external cue: focus on a spot on the wall, or focus on pushing the ground away
is the focus of attention easily measured?
no
- limitation in FOA research, difficult to always know what a person is thinking about
- evenif given an internal FOA cue, they could be thinking ‘what’s for lunch?’
