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.
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.
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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