Week 5 Flashcards
What is perception?
the ability to distinguish and identify sensory information, to direct and sustain attention to various aspects of the environment and to lend meaning to them
Which theories explain perception?
Piaget’s cognitive-developmental view & gibson’s ecological theory
How does Piaget’s cognitive developmental view explain perception?
- children construct the outside world themselves
- children ‘learn’ perceptual skills over time
- action leads to perception
→ internal action (thinking about an object)
→ external action (doing something with the object) - “grasp” object to realize its graspable
How does Gibson’s ecological theory explain perception?
- children actively search for information in environment
- children are ‘born’ with perception skills
- perception leads to action
→ vision is for seeing, fingers are for grasping - characterisitcs of environment offer affordances
What is the information processing view of perception?
sensory input: stimuli - light, sound, touch, smell, taste
processing system:
- receptors in the visual, auditory, kinesthetic, tactual, olfactory, gustatory systems
- processing by CNS
output: motor response
What are the main things to know about vision?
- vision is the dominant perceptual modality for many
- 80% of all sensory information is channeled through visual system
- helps provide information to support a person to organize and carry out a motor behaviour
- people with blind or low vision rely on other more heightened senses
Briefly describe the visual process
- eyes receive light and generate messages
- optic nerve: visual pathway that transmits messages to brain
→ travels through thalamus and reaches visual cortex in the occipital lobe
→ visual cortex receives a projected image - visual cortex transmits information to other parts of the brain for interpretation
Describe visual development
- birth:
→ developed eye structurally, but lack myelination and synaptic connection
→ no fovea - where central visual images are formed
→ spatial resolution is poor - 2 months: infants’ visual cortex starts processing
- 5 months: myelinated
- 1 year: eye of an adult
What is the eye of a newborn like?
- shorter eyeball
- farsightedness
- undeveloped fovea
- under-developed cornea: difficulty focusing
What is visual acuity?
clearness of vision and the capacity to detect both small stimuli and small details of large visual patterns
Describe newborn and adult acuity
newborn: 20/200 - 20/600
adult: 20/20
What is static visual acuity?
ability to detect detail in a stationary object
What is dynamic visual acuity?
ability to percieve detail in a moving
Describe the growth of visual acuity
- static develops before dynamic
- focus depends on speed an object is moving
- dynamic acuity increases with age, stabilizes between afes 12 and 40
What is object permanence?
realizing objects continue to exist when they can no longer be seen
What is the development of object permanence?
- Object shown and then hidden from view - infants lose interest (1-4 months)
- successfully reach objects (4-8 months)
- object permanence emerges (8-12 months)
→ search for objects where they first found it rather than where they last saw it - Object permanence improved (12-18 months)
→ search for object where they last saw it
→ challenged by invisible displacement - Integration (18 months to 2 years)
→ keep track of invisibly displaced objects
→ can integrate perception with action
→ concurrent with cortical maturation at this time
What is the A not B error and when does it occur?
(8-12 months)
- infant is stuck searching for objects where they first found it, rather than where it was last seen
- possible reasons:
→ conceptual error
→ inhibition hypothesis
→ memory explanation
→ attention hypotheses
- perception involves several systems working both separately and together (information processing - can be multiple reasons at once
What is size constancy
the ability to perceive an object as the same size, even when it’s viewed from different distances
What is location constancy?
the tendency to perceive an object as remaining in the same location, even if your body moves
What is colour constancy?
the visual system’s ability to perceive an object’s colour as relatively stable even when the lighting conditions change
What is brightness constancy?
the tendency to perceive an object as having a consistent brightness, even when the amount of light changes
What is shape constancy?
the ability to recognize that an object’s shape remains the same even when viewed from different angles or positions.
What is auditory constancy?
the ability to perceive a sound as the same, even when its physical characteristics like pitch, loudness, or timbre change due to factors like distance or environment
What is spatial orientation?
ability to recognize an object’s orientation or position in 3D spaces
What is the development spatial orientation?
- 3-4 years old: understand dualisms; e.g. over/under, front/back, but can get confused
- sequence of growth: vertical → horizontal → diagonal or oblique
- mostly developed by age 8
What is figure ground perception?
ability to distinguish an object from its surrounding background
Important for
→ focus on and give selective attention to a visual stimulus
→ tracking or intercepting objects in sports
What is the development of figure ground perception?
improves from 4-12 years old
What is depth perception?
ability to judge the distance of an object from the self
What is absolute distance?
precise judgment of the space from the person to an object
What is relative distance?
estimation of distance between one object and another or between different parts of a single object
How does depth perception develop?
- absent at birth
- 6 months - can judge depth
Oculomotor cues are derived from…
kinesthetic receptors in muscles and joints
What are monocular cues and what is their accomodation?
info from one eye
- lens changes shape
What are binocular cues? What is convergence?
- info from both eyes
- eyes move inward to focus on an object
What are visual cues?
information gathered from visual perception, using both eyes or one eye
What are the different cues to know?
relative height cue, occlusion cue, relative size cue, shadow cue, texture gradient cue, atmospheric perspective cue
What is the field of vision?
entire extent of the environment that can be seen without changing the fixation of the eye
- full lateral visual field is 180-190 º
Describe the development of field of vision
- limited at birth
- ~40% developed by 7 weeks
- fully developed by age 5
What are saccadic eye movements?
rapid movements beyond one point of visual fixation
Describe saccadic eye movement development
- infants need multiple saccades to reach a visual target
- matures at 12 months
Describe the development of finding moving objects
- newborns find it hard to focus both eyes on the same point
- 2 months, can track more accurately
- 4 months, can track and predict path
- unrefined visual-motor stage, try to approach with upper body
What is coincident timing?
coordinate visual and motor behaviour to a single coincident point
- kicking a moving ball, catching a ball, passing a ball to a running player
- harder with more speed
Describe the development of coincident timing
- develops between 6-12 years old
- mainly built based on skill-building opportunities (amount of time playing sports, video games)
What is kinesthetic perception?
- our sense of body position or body movement
- takes information from internal environment i.e. the muscles, tendons, joints, and the vestibular (balance)
- in contrast to the visual, auditory and tactile perception which takes input from outside the body
What system is used for kinesthetics?
somatosensory system: handles sensation from the body, receiving information from somatic receptors
Name and describe the two somatic receptors
cutaneous receptors
- at skin level
- perceive touch, pressure, temperature, pain
proprioceptors
- in muscles, joints, tendons, inner ear
- involved in kinesthesis
What is kinesthetic discrimination acuity? When does it reach maturity
- ability to proprioceptively detect differences or match quantities such as location, distance, weight, force, speed and acceleration
- reaches maturity at age 8
What is kinesthetic memory? When does it reach maturity?
- when stimulus is removed after presentation
- reaches maturity after age 12
What are the 5 types of basic movement awareness?
body, spatial, directional, vestibular, rhythmic (temporal)
What is body awareness?
knowing the parts of the body, how they’re related, where they are, and what body parts can and can’t do
How does body awareness develop?
- newborn: no awareness
- 1st month: aware that the body is different from surroundings
- 1st year: can identify major body parts correctly when given verbal cues (learn on own bodies first, then on other people)
- by 6 years - most kids can identify their major parts, and then minor parts after
What is spatial awareness?
drawing inferences in relationship to self-space or position and object recognition
- egocentric or allocentric
What is egocentric localization?
ability to locate objects in space in reference to the self, which is characteristic of younger children
What is allocentric localization?
ability to locate objects using something other than the self as reference
How does spatial awareness develop?
Infants until age 1 primarily use egocentric. Allocentric framing appears 12-16 months
What is directional awareness?
conscious awareness of having two sides of the body, understanding dimensions of external space and projecting the body in that space
What is laterality and how does it develop?
Awareness that the body has two sides (left, right)
- improves until age 5
- sometimes still get confused
- maturity by age 7
What is directionality? How does it develop?
Awareness of dimensions of external space and projecting the body in that space
- age 4: children aware of spatial dualisms
- master spatial dimensions in fairly orderly sequence
- age 8: can perceive spatial orientation of objects
- have troubles with right-left or mirror-image reversal
What is Vestibular Awarness? What are the three types to know?
- ability to establish and maintain equilibrium (balance); a fundamental component to most movement activities
- postural, static, and dynamic
What is postural balance?
Reflex functioning that enables us to maintain upright posture, hold the head up, sitting, standing
What is static balance?
maintaining posture while not moving
What is dynamic balance?
maintain posture while moving
How does vestibular awareness develop?
- develop static and dynamic balance differently
- most adultlike balance happens after 12 years old
- dynamic systems: dependent on the person’s ability to self-organize motor abilities to changing characteristics of the environment
What is rhythmic (temporal awareness)?
Creating or maintaining a temporal pattern within a set of movements
Examples: keeping time in music, tapping hands or feet, reproducing patterns from memory etc.
How does rhythmic awareness develop?
- in infancy: built-in internal awareness of rhythm, rather than in reaction to external stimulation
- more accurate as we grow from childhood to adulthood
- better accuracy at fast rather than very slow tempos - similar to coincident timing
What is auditory perception?
ability to detect, discriminate, associate and interpret auditory stimuli
What is auditory localization?
awareness of where sounds are coming from
What is auditory discrimination?
Detecting differences or similarities between two or more sounds
What is auditory figure-ground perception?
Being able to selectively hear a sound from a backdrop of many sounds
How does auditory perception develop?
newborns:
- turn their eyes to source of sound
- respond to different pitches (low pitches = calm; high pitches = stressed)
- can tell duration
4 months:
- most new sounds stimulate search
- head turns, reaches, moves to sound
6 months: infants are as sensitive to sound as adults
12 months: locate distal auditory stimuli
Age 3:
- localize general direction of sounds
- mastery of basic audio skills
Childhood to adolescence (13):
- discriminate sounds better
- audio skills reach maturity
What is tactile perception?
to detect and interpret sensory information cutaneously (of or on skin)
In early infancy, reflexes like grasping, rooting etc. happen via….
touch
What is the tactile kinesthetic system?
- rely on touch to move around in space
- blind and low vision folks really relay on tactile sense
How does tactile perception develop?
- not much is known
- touch receptors grow in numbers and closer proximity
- developed well by age 8
- maturity around age 8
- tactile object recognition develops before visual object recognition (infant learns hot, cold, sharp early - associated that with objects)
- visual recognition takes over at age 4
- by age 8, can reproduce a design thats draw on parts of their body
What is intermodal perception? How does it develop?
Translate/perceive information from one sensory modality to another e.g. touching an object while blindfolded, then recognizing the object when seeing it
development:
- partially functional at birth
- improves with age
What is perceptual integration?
intersensory simultaneous use of more than one system to perceive
Eg. bike riding (balance, visual, proprioceptive), playing an instrument (auditory, visual, proprioceptive, tactile)
How does visual-kinesthetic integration develop?
2-3 weeks: can imitate mouth and tongue movements of adults
1 month: can recognize objects they has in their mouth previously
6 months: can recognize objects after exploring with their hands alone
5 years old: mostly developed
11 years old: full maturity
How does visual-auditory integration develop?
newborn: move eyes to direction of sounds
4 months: link visual and auditory stimuli
- improves until 12 years old
How does auditory-kinesthetic integration develop?
- natural compatability between auditory and kinesthetic modes
- growth present by age 5: can tactually identify and select an object when told its name
- small differences between 5-10 years old
Visual perception declines happen through…
- loss of visual acuity
- presbyopia
- sensitivity to light
- low depth perception
When does loss of visual acuity occur?
between 40-50
What is presbyopia?
- reduced elasticity of lens
- cant change curvature to allow for close vision
Why and how do we become more sensitive to light as we age?
- lens is thicker, yellowed and less transparent
- reduced light transmission through the lens
- challenged in dim light
- glare
How does low depth perception lead to visual perception declines?
- no change until age 60, declines after
- harder to see how high/low or close/far something is
Describe the auditory perception declines as we age
- presbycusis: gradual hearing loss
- begins around mid 30s, continues until 80s
- gradual deterioration and hardening of the auditory nerve cells
- can’t hear higher frequency tones as well
- environmental stressors can contribute to accelerates hearing decline
How does kinesthetic perception change as we age?
- little understanding
somatosensory: - touch sensitivity declines (especially in lower body)
- reduced touch receptors on skin
vestibular system: - declines in balance ~40
- marked decline after age 70
- gradual deterioration of vestibular nerves
- weight discrimination decreases
How the infant acts on the affordance can depend on….
- developmental level
- past experiences
- present needs
- cognitive awareness of what the object might be used for
Affordances focus on the ________ ___ between the individual and the situation
ecological fit
What is embodiment?
- cognitive processes are grounded in our bodily interactions with the environment
- we create mental models and representations based on actions in the environment (using fingers for counting)
