Ch 6 - sensory, perception, attn Flashcards
Constructivists
on the side of nurture
- Argue that perceptions are constructed through learning
Nativist
on the side of nature
- Argue that innate capabilities and maturational programs drive perceptual development and that perception does not require interpretation
Main methods used for studying infant perception
Habituation
Preferential looking
Evoked potentials
Operant conditioning
Habituation
The process of learning to be bored with a stimulus
- used to test for discrimination of stimuli by all the senses
Preferential looking
- Researchers present an infant with two stimuli at the same time and measure the length of time the infant spends looking at each
- A preference for one over the other indicates that the infant discriminates between the two stimuli
Evoked potentials
Researchers can assess how an infant’s brain responds to stimulation by measuring its electrical conductivity
Infant and vision.. they can -
detect changes in brightness and can track a slow-moving object or picture
Visual acuity as an infant
ability to perceive detail
Optimal at about 8 inches from the face or if objects are boldly patterned with sharp light-dark contrasts
Visual accommodation - infant
– ability to focus on objects at different distances
Takes 6 months to 1 year before can see as well as an adult
Infants’ visual preferences
- Attracted to patterns that have light-dark transitions, or contour
Sharp boundaries between light and dark areas, such as offered by black and white objects - Attracted to displays that are dynamic – contain movement – rather than static
Can track a slow-moving object - Attracted to moderately complex patterns
Prefer clear patterns (checkerboard) to blank or complex stimuli
Prefer “top-heavy” patterns such as the human face
Depth perception - Newborns
- appear to have size constancy
- Recognition that an object is the same size despite changes in its distance from the eyes
Classic study to examine depth perception in infants using the visual cliff: Gibson & Walk (1960)
- Most infants older than 6 ½ months crossed the “shallow” pattern but would not cross the “deep” or “cliff” pattern
- Infants can perceive the cliff by 2 months
- Most infants of crawling age (typically 7 months or older) clearly perceive depth and have learned to fear drop-offs
(in re research on infant vision) infants have intuitive theories –
- organized systems of knowledge
– that allow them to make sense of the world
Hearing - Basic capacities are present at birth
- Can hear better than they can see
- Can localize sounds
- Can be startled by loud noises
- Can turn toward soft sounds
- Prefer relatively complex auditory stimuli
- Can discriminate among sounds that differ in loudness, duration, direction, and frequency/pitch
The pioneering research of Eimas (1975, 1985) demonstrated …
that infants could distinguish similar consonants (ba and pa) and vowels (a and i) and between standard and rarely heard sounds
- can discriminate basic phonemes
Gibson (1988) suggested that infants engage in three phases of exploratory behavior
- From birth to 4 months, infants explore their immediate surroundings by looking and listening and especially by mouthing objects and watching them move
- From 5 to 7 months, once infants can grasp, they explore objects with their hands as well as with their eyes
- By 8 or 9 months, infants use crawling to extend their explorations into the larger environment and carefully examine an object by fingering it, poking it, and watching it
Among humans, early experiences affect the development of vision during multiple sensitive periods, which refers to -
“. . . a window of time during which an individual is more affected by experience, and thus has a higher level of plasticity than at other times throughout life . . . ”
Sensory experience is vital in
determining the organization of the developing brain
Sensory and perceptual development is largely complete at …
the end of infancy and becomes more refined during childhood
- learn to use their senses more intelligently
Infants are “captured by” something –
they react to environmental events
They have an “orienting system”
Children are “directed toward” something
They have a focusing system that seeks out and maintains attention to events
Improvements in sustained attention occur from ages .. because…
age 5-6 to ages 8-9
- as the parts of the brain involved with attention become further myelinated
selective attention –
deliberately concentrating on one thing while ignoring something else
- infants not good at this
When do children become systematic in their visual searchs?
In a research study (Vurpillot, 1968)
- children aged 4-5 were not systematic in a visual search
- but most children older than 6 were very systematic
Exposure to sounds above _____ can result in hearing loss
75 decibels
tinnitus –
ringing sounds in one or both ears
Changes in taste during adolescence
- Slight decline in preference for sweets and an increased sensitivity to sour tastes
- Adolescents are more likely to have an acquired taste for previously disliked or avoided foods
Sense of smell in adolescence
Women generally demonstrate greater sensitivity than men to a variety of odors (including body odor)
Sensory losses take two forms in adults
- Sensory thresholds are higher
- Sensitivity to very low levels of stimulation is lost - Perceptual abilities decline in some aging adults
- Difficulty in processing or interpreting sensory information
Adult and aging - vision
- Pupils become smaller and do not respond as much when lighting conditions change
- Sharp drop in visual acuity when contrast is poor and light levels are low
- Dark adaptation occurs more slowly
- The lens becomes denser and less flexible
- Cannot accommodate to bring objects at different differences into focus
- Thickening of the lens results in presbyopia, decreased ability to accommodate objects close to the eye
Age-related macular degeneration (AMD) results from
damage to retinal cells responsible for central vision
- Vision becomes blurry and begins to fade from the center of the visual field – blank or dark space in the center of the image
- Leading cause of blindness in older adults
- Causes are unknown and there is no cure
Loss of peripheral vision leads to
Retinitis pigmentosa is a …
group of hereditary disorders that involve gradual deterioration of the light-sensitive cells of the retina
Glaucoma is caused by ..
increased fluid pressure in the eye that can damage the optic nerve, cause loss of peripheral vision, and lead to blindness
Older adults have the greatest difficulties in processing visual information when …
- the situation is novel (when they are not sure exactly what to look for or where to look) and - when it is complex (there are many distractions)
Most age-related hearing problems originate in
the inner ear
- Auditory receptors and hearing-related structures and neurons degenerate during adulthood and result in presbycusis
Among older adults, hearing impairments are ___ times as prevalent as visual impairments
- three times
Among adults aged 65 and older, as many as ___ have mildly impaired hearing that progressively worsens with age
- 90 percent
The most common form of presbycusis is
.. loss of sensitivity to high-frequency or high-pitched sounds
- Results in difficulty hearing a child’s high voice, the flutes in an orchestra, or high-frequency consonant sounds such as s, z, and ch
After age 50, it also becomes difficult to hear
lower-frequency sounds
