Motor Development Exam 2

Sensation

neural activity triggered by stimulus that activates a sensory receptor

1) stimulus 2) trigger 3) receptor

only involves sending information to the brain

Perception

Process of attaching meaning to sensory stimuli

Multistage process including selecting, processing, organizing, integrating

• what to do about a sensation (response)

Visual acuity

sharpness of sight and quality of the information

visual acuity in newborns

20/400 - what a normal person can see at 400 feet, they need to be at 20 feet to see

full visual acuity (20/20) occurs around age 10

What two factors cause visual acuity to decline throughout adulthood

• Yellowing lenses (able to see less)

• Less of retinal illuminance (light through retina)

• 60-year-olds receive 60% less light than 30-year-old

What three things are needed to assign value to stimulus

Perception of space, perception of objects, perception of motion

Perception of space

using two-dimensional visual information to perceive depth and distance

Perception of objects

Use of edges and boundaries to extract objects from embedded environment

Perception of motion

perception of change of an object’s position over time

Depth perception

Part of perception of space

judgement of distance from self to object and location in space

develops around 6 months

entirely dependent on visual

Two categories of depth perception

retinal disparity

optic flow

Retinal disparity

differences in images received by two eyes on the retina and comparing the images provides information about depth perception

different angles

Eyes are separate and the optic nerve senses light which pieces the picture together

Optic flow

change in pattern of optical texture as viewer moves forward or backward in environment

As we move, we see more info from objects that were hidden before.

Figure-ground perception

using edges and boundaries to see objects as distinct from their background

children improve between 4-10 years old

• perception of objects

Whole-Part perception

using edges and boundaries to distinguish whole objects from parts of an object (dog made of screws)

Begins developing at age 9

part of perception of objects

Detection thresholds

part of perception of motion

point on continuum that is necessary to perceive presence of motion

(position, velocity, acceleration)

much higher for newborns and older adults

Size constancy

perception of actual object size despite object’s image as projected on retinas

know the size of a basketball no matter how close or far away it is

newborns have this

Shape constancy

perception of actual object shape despite object’s orientation to a viewer

A pumpkin upside down is still a pumpkin

newborns have this

Face percpetion

ability to detect a face, discriminate a particular face among others, and create a memory of a particular face

developed early in life - newborn

Kinesthetic sensation

use of proprioceptive systems to determine information about body sense

1) somatosensors

2) vestibular apparatus

somatosensors

provide sense of where we are in space (relative to joint or entire body

Vestibular semicircular canals

There is fluid in canals that detect

1) nodding movement

2) lateral head movement

3) rotational movement

Tactile localization

ability to place stimulus on the body

sensitivity

ability to detect stimulus

Precision / acuity

discriminate between stimuli

When can you identify major body parts

age 4 - 9

When can you develop object sense of self

ability to recognize themselves

age 2

Laterality

awareness that the body has two distinct sides

age 4-5

Lateral dominance

consistent preference for use of one side of the body

Spatial orientation

perception of body’s location and orientation in space independent of vision

INFORMED BY VISION BUT NOT DEPENDENT

somatosensors and vestibulosensors

Directionality

ability to grasp spatial concepts about the movements or locations of objects in the environment relative to the body

Improves after laterality between 6-12

Auditory sensation

• externam ear

• middle ear

• cochlea of inner ear

newborns have 60dB higher than adults - more range

Auditory Perception

locate a sound by determining direction and distance from us

sound discrimination

• direction

• using both ears to figure out where sound is coming from with localized sound and pinpoint accuracy (increase with age)

7-10 months: 12-19 degrees

can identify sounds by age 3

when can you discriminate basic speech sounds

1-4 months

accuracy and discrimination continue to improve until 13

Intermodal perception

process of integrating information from different sensual modalities into a single, unified experience

• auditory-visual

• visual-kinesthetic

• auditory-kinesthetic

• spatial-temporal

when do you match vocal expressions of other infants with facial expressions

5 months

Auditory-tactile integration tests

saying a shape and then being able to feel it and identify it without seeing it.

8 year olds perform better than 6 year olds

When does auditory-visual perception develop

age 5-12

does performance of stimuli centrally of peripherally show better

centrally

when can infants identify vision and touch body

4 months they feel something touch their body and know where it is)

which is more difficult for 5 or K-K or V-V

K-K

Two-way interaction between sensory perception and motor action

Perception-Action coupling

perceptions inform actions

Neurogenesis

making more neuron connections

How do infants have limited perception

visual acuity and sound localiazation

Brain-derived Neurotrophic Factor (BDNF)

group of proteins responsible for neurogenesis, synaptic plasticity, and strengthening connections between neurons

Where is BDNF expressed

skeletal muscle, increases with response to exercise, positive correlation to aerobic fitness

Who is more likely to go over the visual cliff

early crawlers less likely to go over than late crawlers

Self produced locomotion

interaction between motor development, perceptual development, and cognitive development

infants transfer learned information from one posture to new ones

Self-produced locomotion: slope perception

crawlers attempts go down slope no matter how steep, walkers will refuse

Self-produced locomotion: spatial perception

deals with dimension of objects, distance of objects from body, object relation within the environment

Object permanence

objects still exist even if they are hidden

beings 4-6 months, fully developed by 12 months

detouring

moving around a barrier to achieve a goal. By one year you can understand detours and 14 months can navigate adjustments when barrier is changed

Body scaling

person’s size relative to environment - changes over lifespan

Posture

orientation of anybody segment relative to the gravitational vector

balance

dynamics of changing body posture to prevent falling (maintaining equilibrium)

static balance

maintain balance without movement ex. handstand

dynamic

consistently maintain balance while moving ex. walking

Degrees of freedom

variables how objects move

task dependent balance

change how we view (eyes closed / eyes open)

two frames of reference for balance

supporting surface, gravity

Assainte model

1) birth to standing head to toe direction of muscular control

2) standing to 6 years old: coordination of upper and lower body

3) 7 years old through adolescence: refinement of head stabilization

4) adulthood: refinement of degrees of freedom in the neck (changing posture)

motor learning

relatively permanent gains in motor skill capability associated with practice or experience

developmental motor learning

focuses on how individuals may learn differently across the lifespan

how long does motor learning take

hours, minutes, days (practice)

how long does motor development take

weeks, months, years

Fitts and Posner’s Stages

1) cognitive

2) associative

3) autonomous

cognitive stage

getting idea of movement, lots of errors and inconsistent variables

Associative stage

refining movement, attention lessens, less errors and correcting errors

Autonomous stage

little attention required, focus more on situation and environment

Bernstein’s Model of motor learning definition

use dynamical systems to understand how we manipulate degrees of freedom to achieve coordinated movement

Stages of Bernstein’s model of motor learning

1) freezing degrees of freedom

2) releasing degrees of freedom

3) exploiting degrees of freedom

freezing degrees of freedom

minimize movement, joints locked

releasing degrees of freedom

fluid, coordinated movement

exploiting degrees of freedom

adopting strategies to optimize movement, efficient and effective

constant practice

constraints of task don’t change

benefit: good at recognizing movement

varied practice

constraints change throughout practice

promotes schema learning

schema learning

acquisition of rules related to task performance that can be applied to new tasks

rules for one task transferred to another

Intrinsic feedbackl

movement from sensory receptors

ex. what it feels like

extrinsic feedback

from source external to performer to provide additional context

• from coach

knowledge of results

verbalized information about outcome of motor performance

• coach or audience applause

knowledge of performance

how a person moved, verbal or technology

• descriptive or prescriptive

descriptive KOP

description of how individual moved

Prescriptive KOP

provide information about how to improve movement

simple reaction time

online button test (just click when green)

Simple/choice reaction time

go/ no go online game