Glynell May peers through goggles that simulate glaucoma.
Ms. May participates in the touch sensitization task.
Sydne Steinberg checks Ms. May's peripheral vision.
Glynell May peers through goggles that simulate glaucoma.
Ms. May participates in the touch sensitization task.
Sydne Steinberg checks Ms. May's peripheral vision.
Each of the participants also received the following information on a handout.
Why do we study perception?
To understand that perception involves a complex process in which numerous components
(eyes, nose, mouth, and hair) are combined into a single organized percept; and to
learn how the processes behind such common perceptions as seeing a friend or observing
an object from different angles happens. We also study perception to understand the
perceptual differences between people, and to help fix certain deficiencies such as
vision loss.
How do we study perception?
One way is by studying the relationship between stimuli from the environment and
people's perception of these stimuli. This is done by measuring the relationship
between stimuli and perception; psychophysics is the term used for these quantitative
methods of stimulus detection and magnitude estimation. Another way psychophysics is
applied is by identification of information that we use to perceive perceptual
qualities in the environment. For example, the visual acuity, color vision, and smell
tests that you performed today are psychophysical measurements.
Perception, though quite fascinating, is a very difficult area to study because
of the complexity of the brain. Due to this complexity, researchers have often had
to simplify this area by breaking it down into one area with two parts: PSYCHOPHYSICS
(psycho= the brain, physical= the body). Sometimes one part must be studied
in order to know why the other part is functioning (or not) as it is.
Since the brain has so many intricate parts and pathways it has been found that
non-invasive methods such as PET and CAT scans and MRIs are the most effective on
humans. This way the overall picture of the brain is seen without harming the person,
and if there is an abnormality in the picture then researchers or doctors usually
know what part of the brain is causing the dysfunction in the body (or in perception).
Another method, an evasive one, used mostly in research with animals, is a lesion.
This is when an actual part of the brain is removed from an animal, in order to
research the actual part itself or to observe the animal to see how it can or can't
function without it. This helps researchers to distinguish such things as what part
of the brain we need in order to live, what part can be operated on, and what parts
cause us to perceive different things as we do.
Researchers examine the perceptual system across all ages to determine how different
areas of the system change over time. Initially, the change is a good one. At birth,
the perceptual system is poorly developed. It improves rapidly during the first months
of life. By an infant's first birthday, the perceptual abilities are similar to those
of an adult. After a number of relatively stable years, the system gradually begins
to deteriorate as an individual reaches older adulthood. With extensive studies of
age-related perceptual functioning, researchers could learn how to treat, and possibly
even prevent, the perceptual decline that aging individuals must face.
Infant Psychophysics
Since infants are unable to verbalize their perceptual experience to researchers, special
psychophysical techniques have replaced the traditional question and answer methods used
on older children and adults. The preferential looking technique was developed based on
the fact that infants tend to look longer at stimuli that interest them. When using this
technique, researchers present two stimuli, and by observing the infants' looking
preferences, can determine whether the infant sees a difference between the two stimuli.
The second special technique for measuring infants' psychophysical responses, habituation,
relies on the observation that infants prefer to look at a new stimulus rather than a
familiar one. In a habituation activity, one stimulus is presented repeatedly until the
infant becomes less interested in attending to it. A new stimulus is presented to
determine if the infant can tell the difference between each stimuli. If the difference
is noticeable, the infant will show an increased interest in the new stimuli, while
unnoticeable differences will only increase disinterest of the infant.
By using the preferential looking and habituation techniques, researcher have measured
infants' ability to perceive qualities such as depth, color, movement, sound, and smell.
They have discovered that while infants' perceptions are limited in the first few months
of life, by age six to nine months infants have perceptual abilities similar to adults.
Elderly
As the perceptual system ages, it undergoes various changes that often alter it's
functioning. The ability to process certain types of stimuli may decline or even
completely deteriorate. Because of these changes, the elderly often experience a
reduction in their perceptual ability. It becomes increasingly difficult for older
individuals to resolve fine detail, discriminate between colors, estimate depth, hear
high-pitched noises, and smell common odors.
The implications of a decline in the various perceptual systems often have a marked effect
on the lifestyle of the older generation. For some, it means losing meaningful social
contact with others, as well as a gradual loss of freedom. They are forced to rely on a
network of friends and family for things necessary to their survival. Many elderly
individuals understandably develop feeling of frustration, despair, and bitterness as a
result of their perceptual deficiencies.
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