SENSATION AND PERCEPTION

REVIEW OF RELATED LITERATURE (FOREIGN) I. PSYCHOLOGY (Douglas A. Bernstein, Edward J. Roy, Thomas K. Skull, Christopher D. Wickens)
BIOLOGICAL ASPECTS OF PSYCHOLOGY

CONSCIOUSNESS MOTIVATION
EMOTION
PERCEPTION

SENSATION

The diagram above illustrates some of the relationships between different aspects of psychology through sensation. What happens if people are denied on this contact, if they deprived of stimulation form the senses? However, recent research has made it more difficult to draw a clear line between sensation and perception. That research shows that the process of interpreting sensations begins in the sense organs themselves and continues into the brain. Even previous experience can shape what you sense, causing you not to notice.

Sensory Systems
The senses gather information about the world by detecting various forms of energy, such as sound, light, heat, and physical pressure. For example, the eyes detect light energy, the ears detect the of sound , and the skin detects the energy of heat and pressure. Humans depend primarily on vision, hearing, and the skin senses to gain information about the world: they depend less than other animals on smell and taste. There are also senses that provide information to the brain from the rest of the body. All of these senses must detect stimuli, encode them into neural activity, and transfer this coded information to the brain.

Steps in Sensation
At each step, sensory information is processed in some way: the information that arrives at one point in the system is not the same as to the information that goes to the next step. In some sensory systems, the first step in sensation involves accessory structures, which modify the stimulus. The lens of the eye is an accessory structure that changes incoming light by focusing it; the outer part of the ear is an accessory structure that collects sound.
The second step in sensation is transduction, which is the process of converting incoming energy into neural activity. Just as radio receives energy and transduce it into sounds, the ears receive sound energy and transducer it into neural activity that people recognizes as voices, music, and other auditory experience. Transduction takes place at structures called receptors, cells that are specialized to detect certain forms of energy. These sensory receptors are distinct from neurotransmitter receptors. But both types of receptors translate one kind of signal into a different kind of signal. Sensory receptors respond best to changes in energy. A constant level of stimulation usually produces adaption, a process through which responsiveness to an unchanging stimulus decreases over time.
Next, the output from receptors is transferred to the brain via sensory nerves. For all the senses but smell, the information is taken first to the thalamus, which relays it to the cerebral cortex. It is in the cortex that the most complex processing occurs.
HEARING
Sound is a repetitive fluctuation in the pressure of a medium like air; it travels in waves that can be represented as waveforms. The frequency (which is inversely related to wavelength) and amplitude sound waves produce the psychological dimensions of pitch and loudness, respectively. Timbre, the quality of sounds depends on complex wave patterns that are added on to the basic frequency of the sound.
VISION
Visible light is electromagnetic radiation with a wavelength of about 400 to 750 nanometers. Light intensity, or the amount of energy in light, determines its brightness. Differing light wavelengths are sensed as different colors. The accessory structure of the eye includes the cornea, pupil, iris, and lens. Through accommodation and other means, these structures focus light rays on the retina, the netlike structure of cells at the back of the eye. Photoreceptors in the retina—cones and rods—have photopigments and can transducer light into neural activity. Rods and cones differ in their shape, their sensitivity in light, their ability to discriminate colors, and their distribution across the retina. The fovea, the area of the highest acuity, has only cones, which are color sensitive. Rods are more sensitive to light but do not discriminate colors.
Seeing color
The color of an object depends on which the wavelengths striking it are absorbed or which it was reflected. The SENSATION of color has three (3) psychological dimensions: hue, which is the determined by the dominant wavelength in the mixture of light; Saturation, which depends on the relative intensity of a single wavelength; and brightness, which is a function of the overall intensity of all the wavelengths. According to the trichromatic theory, color vision results from the fact that the eye includes three (3) types of cone, each of which is most sensitive to short, medium, or long wavelengths; information from the which it can produce the sensation of color.
PAIN
Pain protects the body from damaging stimuli. Sharp pain and dull, chronic pain are carried by different fibers. The emotional response to pain depends on how the painful stimulus is interpreted. According to the gate control theory, pain signal can be blocked by competing signals from other skin senses and by messages sent form the brain down to the spinal cord. These messages produce natural analgesia.

PERCEPTION
Human
Development

Thought and language Consciousness
Biological aspects of psychology Stress, coping, and health.

PERCEPTION

The diagram above illustrates some of the relationships between sensation and perception, which is the process of interpreting stimulation from the senses. In fact, many pioneers of psychology thought that perception was no more than the sum of sensations, but researchers soon found that perception is more complicated than that. How you perceive the world, it turns out, depends not just on what comes out from you but also on how your perception and knowledge do the concentration.
FROM SENSING TO PERCIEVING: AN OVERVIEW The senses crate a physical code from a stimulus; perception goes beyond this code to draw on knowledge of the world and interpret what is out there. Sensation and perception overlap. The sensory process themselves do some preliminary interpretation of the outside world, highlighting certain features by registering them into greater emphasis than others. There are different approaches perception, The constructionist view of perception suggests that the perceptual systems constructs the experience of reality by interpreting raw sensations on the basis of what people have learned.
ORGANIZING THE PERCEPTUAL WORLD
When people perceive objects or sounds, they automatically discriminate figure from ground. In addition, the perceptual systems automatically groups stimuli into patterns on the basis of gestalt principles of proximity, similarity, continuity, closure, orientation, simplicity, and common face.
Perception of Motion
The perception of motion results, in part from the movement of stimuli across the retina, Expanding, or looming, stimulation of the retina is perceived as an approaching object. Stimulation of the retina by moving objects is interpreted along with information about the movement of the head, eyes, and other parts of the body.
In recognizing the perceptual world a perceptual system is given:
* Feature analysis * Models of object recognition
* top-down processing * top-down and bottom-up process together
ATTENTION
Attention is the process of focusing psychological resources to selectively enhance information processing. A selective attention is a stimuli that attract attention that tend to be high in intensity, novelty, and contrast. people are also more likely to attend in which they are especially interested. people can sometimes attend to two sets of stimuli at once. Especially with practice, if the task are easy or different senses are involved.

II. SENSATION AND PERCEPTION (Eight edition)
(E. Bruce Goldstein)
Sensation & Perception - When we smell a fragrant flower, are we experiencing a sensation or a perception? In everyday language, the terms "sensation" and "perception' are often used interchangeably. However, as you will soon see, they are very distinct, yet complementary processes. In this section, we will discuss some concepts central to the study of sensation and perception and then move on to discuss vision and the perception of pain (it is not possible in the scope of these notes to discuss all the senses).
Sensations can be defined as the passive process of bringing information from the outside world into the body and to the brain. The process is passive in the sense that we do not have to be consciously engaging in a "sensing" process.Perception can be defined as the active process of selecting, organizing, and interpreting the information brought to the brain by the senses.
A) HOW THEY WORK TOGETHER:
1) Sensation occurs:
a) sensory organs absorb energy from a physical stimulus in the environment.
b) sensory receptors convert this energy into neural impulses and send them to the brain.
2) Perception follows:
a) the brain organizes the information and translates it into something meaningful.
b) But what does "meaningful" mean? How do we know what information is important and should be focused on?
1) Selective Attention - process of discriminating between what is important & is irrelevant (Seems redundant: selective-attention?), and is influenced by motivation..
2) Perceptual Expectancy - how we perceive the world is a function of our past experiences, culture, and biological makeup.

In order to measure these events, psychologists use THRESHOLDS.
1) Threshold - a dividing line between what has detectable energy and what does not.
2) Difference Threshold - the minimum amount of stimulus intensity change needed to produce a noticeable change. The greater the intensity (ex., weight) of a stimulus, the greater the change needed to produce a noticeable change.
3) Signal-Detection Theory - detection of a stimulus involves some decision making process as well as a sensory process. Additionally, both sensory and decision making processes are influenced by many more factors than just intensity.

PERCEPTION
Much of our understanding of how and why we perceive things comes from Gestalt Psychology.
A) Gestalt Principles of Perceptual Organization
1) figure-ground 2) simplicity/pragnanz (good form)
3) proximity 4) similarity
5) continuity 6) common fate
B) Illusions - an incorrect perception caused by a distortion of visual sensations.
C) THE PERCEPTION OF PAIN
Pain is an unpleasant yet important function for survival: warning system (but not all pain is needed for survival).

REVIEW OF RELATED LITERATURE (LOCAL) I. Introduction to experimental psychology
(Milagros M. Catabona)
Perception
Perception refers to interpretation of what we take in through our senses. The way we perceive our environment is what makes us different from other animals and different from each other. In this section, we will discuss the various theories on how our sensation are organized and interpreted, and therefore, how we make sense of what we see, hear, taste, touch, and smell.

Gestalt Principles of Grouping
The German word "GESTALT” roughly translates to "whole" or "form," and the Gestalt psychologist's sincerely believed that the whole is greater than the sum of its parts. In order to interpret what we receive through our senses, they theorized that we attempt to organize this information into certain groups. This allows us to interpret the information completely without unneeded repetition. For example, when you see one dot, you perceive it as such, but when you see five dots together, you group them together by saying a "row of dots." Without this tendency to group our perceptions, that same row would be seen as "dot, dot, dot, dot, dot," taking both longer to process and reducing our perceptive ability. The Gestalt principles of grouping include four types: similarity, proximity, continuity, and closure.

Similarity refers to our tendency to group things together based upon how similar to each other they are. In the first figure above, we tend to see two rows of red dots and two rows of black dots. The dots are grouped according to similar color. In the next figure, we tend to perceive three columns of two lines each rather than six different lines. The lines are grouped together because of how close they are to each other, or their proximity to one another. Continuity refers to our tendency to see patterns and therefore perceive things as belonging together if they form some type of continuous pattern. In the third figure, although merely a series of dots, it begins to look like an "X" as we perceive the upper left side as continuing all the way to the lower right and the lower left all the way to the upper right. Finally, in the fourth figure, we demonstrate closure, or our tendency to complete familiar objects that have gaps in them. Even at first glance, we perceive a circle and a square.

Maintaining Perceptual Constancy Imagine if every time an object changed we had to completely reprocess it. The next time you walk toward a building, you would have to re-evaluate the size of the building with each step, because we all know as we get closer, everything gets bigger. The building which once stood only several inches is now somehow more than 50 feet tall. Luckily, this doesn't happen. Due to our ability to maintain constancy in our perceptions, we see that building as the same height no matter what distance it is. Perceptual constancy refers to our ability to see things differently without having to reinterpret the object's properties. There are typically three constancies discussed, including size, shape, brightness. Size constancy refers to our ability to see objects as maintaining the same size even when our distance from them makes things appear larger or smaller. This holds true for all of our senses. As we walk away from our radio, the song appears to get softer. We understand, and perceive it as being just as loud as before. The difference being our distance from what we are sensing. Everybody has seen a plate shaped in the form of a circle. When we see that same plate from an angle, however, it looks more like an ellipse. Shape constancy allows us to perceive that plate as still being a circle even though the angle from which we view it appears to distort the shape. Brightness constancy refers to our ability to recognize that color remains the same regardless of how it looks under different levels of light. That deep blue shirt you wore to the beach suddenly looks black when you walk indoors. Without color constancy, we would be constantly re-interpreting color and would be amazed at the miraculous conversion our clothes undertake.

II. GENERAL PSYCHOLOGY
(Alicia H. Gahayon, Gaudencio V. Aquino)

The nervous system receives input through an array of sense organs (for example, the eye, ear, or nose) and transforms the information into neural processes through a procedure called sensation. (Using the computer analogy, sensation can be compared to computer input.) Each sensory system follows similar principles for the conversion of a physical stimulus into a psychological experience.
The difference threshold—the minimum (physical) distinction between stimulus attributes that can be detected 50% of the time—is also of concern. The difference threshold is also called a just noticeable difference (JND). Ernst Weber, a well-known early investigator, observed that regardless of their magnitude, two stimuli must differ by a constant proportion for their difference to be detectable. His observations are formulated as Weber's law, which states that the “just noticeable difference” is a constant fraction of the stimulus intensity already present.

Vision
Light. The stimulus for vision is light, which travels in waves. The amplitude (wave height) is associated with the sensory experience of brightness; the wavelength determines the hue (color) of the light; and the wave purity (whether there is more than one type of wave) produces the psychological experience of saturation.

Hearing
Sound. Sound, the stimulus for hearing, is made up of a series of pressures, usually of air, that can be represented as waves. Sound waves have three characteristics—amplitude, frequency, and purity—each of which is related to a psychological experience. Greater wave amplitudes are related to greater loudness; wave frequency is related to pitch; and wave purity is related to timbre.

The Chemical Senses: Taste and Smell
Taste. The stimuli for taste are chemical substances dissolved in water or other fluids. Taste can be described as four basic sensations, sweet, sour, salty, and bitter, which can be combined in various ways to make all other taste sensations. Taste receptors (called taste buds) for these sensations are located primarily on various areas of the tongue: front, sweet; sides, sour; sides and front, salty; and back, bitter There are about 10,000 taste buds, which are situated primarily in or around the bumps (papillae) on the tongue. Each papilla contains several taste buds, from which information is sent by afferent nerves to the thalamus and, ultimately, to areas in the cortex.

The Cutaneous (Skin) Senses
The skin contains receptors that respond to touch, pressure, and temperature.
The relationships between receptors and the cutaneous sensations are not completely understood. Meissner's corpuscles are sensitive to touch and Pacinian corpuscles to deep pressure. Ruffini endings transmit information about warmth and Krause's bulbs about cold. Information is transmitted from the receptors to nerve fibers that are routed through the spinal cord to the brainstem. From there they are transmitted to an area of cortex in the parietal lobe. Skin senses also undergo various kinds of sensory adaptation.
Pain
Pain receptors are mostly free nerve endings in the skin. Information is transmitted by two types of pathways to the brain by way of the thalamus. The fast pathway (myelinated) detects localized pain and sends that information rapidly to the cortex. The slow pathway (unmyelinated) carries less-localized, longer-acting pain information (such as that concerning chronic aches). In addition, chemicals in the body called endorphins (chemicals with actions similar to those of morphine) increase in concentration when the body is responding to pain by serving as neuromodulators (chemicals that increase or decrease—modulate—the activity of specific neurotransmitters). The gate control theory of pain, proposed by Ronald Melzack, proposes that a “neurological gate” in the spinal cord controls the transmission of pain impulses to the brain. Determination of whether the gate is open or closed depends upon a complex competition between different types of nerve fibers. Acupuncture is a procedure developed by the Chinese for controlling pain by the insertion of long needles in various parts of the body. Although it is not known precisely how acupuncture alleviates pain, one theory suggests that the needles activate large nerve fibers and close the pain gate, while another suggests that the needles cause the release of endorphins, which serve as analgesics.
The Vestibular Senses
Awareness of body balance and movement are monitored by the vestibular system. The vestibular senses (the sensations of body rotation and of gravitation and movement) arise in the inner ear; the sense organs are the hair cells that send out signals over the auditory nerve. The sensation of body rotation arises in the three semicircular canals in the inner ear. Movement of fluid in the canals stimulates hair cells, which send messages to the brain about speed and direction of body rotation. Gravitation and movement sensations are produced by movement of two vestibular sacs in each ear that lie between the semicircular canal and the cochlea. Both sacs are filled with millions of tiny crystals that bend hair cells when moved. In turn, impulses giving a sense of position are sent to the brain. (Motion sickness originates from excessive stimulation of the vestibular organs.

PERCEPTION
Stimulus Input: Attention and Set
Perception is the way that sensory information is chosen and transformed so that it has meaning. Once sensory input starts, an individual uses perceptual processes to select among sensory input stimuli and to organize them so that relevant action can occur. (In the computer analogy, the process of perception would represent use of both hardware and software in the central nervous system; many of the perceptual processes are innate—hardware—but some may be modified—software.)
Organization of Perceptions
The manner in which stimuli are arranged, that is, grouped, (in addition to their individual characteristics) also affects their perception.
Stimulus characteristics that affect organization. Important stimulus characteristics that affect the organization of stimuli and their perception include the following:
Closure. Closure is the completion of an incomplete stimulus. If someone yells at you, “Close the_____,” the word door isn't said, but you fill in the blank because of past experience and close the door.
Nearness. Stimuli that are near one another tend to be grouped together. stars near one another are sometimes seen as a pattern or constellation, which is not the case for stars that are far apart.
Similarity. Stimuli that are similar to one another are frequently grouped together; people wearing the same band uniforms are seen as similar compared to a group of marching people wearing everyday clothes.
Continuity. The tendency is to view a figure, pattern, or illustration that contains gaps as smooth and continuous rather than as discontinuous. The broken line down the middle of the highway is perceived as a continuous dotted line rather than a long row of blocks.
Contiguity. Contiguity, or nearness in time and space, also influences perception. If certain theme songs and visual stimuli are placed near the beginning or end of television programs, these stimuli are associated with the starting or stopping of the program.

REVIEW OF RELATED STUDIES (FOREIGN) I. GALE SCHOENLEBER STUDY (PAIN)
Introduction:
The pain of childbirth was nothing compare with the headaches gale schoenleber experienced for years. A 36-year old Pennsylvania mother, schoenleber had her first severe headache when she 12, and the attacks grew worse over the years. They became so intense that she would go to the hospital for shots of morphine, and during one recent year she spent two months in bed. She lost weight—and she lost self-esteem, unable as she was to live normal existence.
Schoenlenber suffered from migraine headaches, a severe form of headache so painful that sufferers are almost at a loss for words to describe it. Some call migraines “throbbing”. “hammerlike”. Or “burning”. Author joan didion says they start like a ”pounding terror” and the fact that no one dies of migraine seem, to someone deep into an attack, an ambiguous blessing.
Findings:
For Schoenleber however, all this changed when she was referred to Seymour Solomon, director of the headache unit at MONTIFIORE MEDICAL CENTER in New York. Solomon immediately prescribed a change in medicine, placing schoenleber on a mild tranquilizer and increasing the dosage of beta blocker, a kind of drug that reduces arousal in certain parts of the nervous system. The result of the new treatment: Schoenleber hasn’t had a headache since. Unfortunately, Schoenleber still has to deal with headaches—those of her 8-year old daughter Michele. Migraine headaches run in families, and Michele seems to be developing severe headaches similar tot those suffered by her mother for many years. At least no. however, schoenleber’s freedom from pain allows her to care for her daughter, something she was unable to do before her own successful treatment (monmaney, 2007)

Conclusion and Summary: Fourtunately, most of us do not suffer the delibitating pain of migraine headaches. Yet the presence of this kind of misery among our fellow human beings clearly illustrates the profound effect our bodily sensations have our day-to-day behavior. Pain, of course, is just one of the sensations to which we are sensitive; we also respond to light, sound, tastes, smells, and a variety of other stimulation that comes from the world around us.

II. Adults Fooled by Visual Illusion, But Not Kids BY BRUCE BOWER, SCIENCE NEWS

Introduction: Sometimes seeing means deceiving before believing, depending on your age. Children and adults size up objects differently, giving youngsters protection against a visual illusion that bedevils their elders, a new study suggests.
This unusual triumph of kids over grown-ups suggests that the brain’s capacity to consider the context of visual scenes, and not just focus on parts of scenes, develops slowly, say psychologist Martin Doherty of the University of Stirling in Scotland and his colleagues. Even at age 10, children lack adults’ attunement to visual context, Doherty’s team concludes in a paper published online November 12 in Developmental Science.

Findings:
This unusual triumph of kids over grown-ups suggests that the brain’s capacity to consider the context of visual scenes, and not just focus on parts of scenes, develops slowly, say psychologist Martin Doherty of the University of Stirling in Scotland and his colleagues. Even at age 10, children lack adults’ attunement to visual context, Doherty’s team concludes in a paper published online November 12 in Developmental Science. As a result, visual context can be experimentally manipulated to distort adults’ perception of objects’ sizes. But Doherty’s group finds that children, especially those younger than 7, show little evidence of altered size perception on a task called the Ebbinghaus illusion.
“When visual context is misleading, adults literally see the world less accurately than they did as children,” Doherty says. This pattern holds for Scottish children and adults in the new study as well as for Japanese children and adults who participated in other investigations conducted by Doherty’s team. Some researchers argue that East Asians focus broadly on the context of what they see while Westerners focus narrowly on central figures. Doherty says the new findings instead indicate that adults in both Scotland and Japan can’t help but track visual context, although this tendency was stronger in the Japanese adults.
Psychologist Carl Granrud of the University of Northern Colorado in Greeley calls the new study convincing but “somewhat surprising.” Children exhibit sensitivity to visual context on some other visual tasks, he says, such as one in which two equal-sized horizontal lines are perceived as differing in length when flanked by diagonal lines. Earlier research has yielded conflicting evidence that children fall prey to the Ebbinghaus illusion, partly because of weaknesses in study designs, Doherty says. His team studied 151 children, ages 4 to 10, recruited from a Scottish primary school and nursery school. Another 24 volunteers, ages 18 to 25, were college students. Participants viewed a series of images containing pairs of orange circles in which one circle was 2 percent to 18 percent larger than the other. An experimenter asked participants to point to the circle that “looked bigger.”
Control images showed only two orange circles. In other images, each orange circle was surrounded by gray circles intended either to hinder or aid accurate size perception. Misleading images showed the smaller orange circle surrounded by even smaller gray circles to boost its apparent size. Large gray circles surrounding the larger orange circle were intended to shrink its apparent size.In helpful images, large gray circles surrounded the smaller orange circle to make it appear smaller than it actually was. Small circles surrounded the larger orange circle to magnify its apparent size.
Summary and conclusion:
Four-year-olds correctly identified the larger circle in 79 percent of control images. That figure rose with age, reaching 95 percent in adults. For 4- to 6-year-olds, accuracy of size perception for misleading images remained at about what it was for control images. Misleading images increasingly elicited errors from older children and tricked adults most of the time. Adults made almost no errors on helpful images. Kids from age 7 to 10 erred on a minority of helpful images, while 4- to 6-year-olds performed no better than chance.

REFERENCES

1. Elements of Psychology ( Robert S. Fieldman) 2. Psychology 2nd edition (Douglas Bernstein, Edward Roy, Thomas Skull, Chritopher Wickens) 3. SENSATION AND PERCEPTION (Eight edition) (E. Bruce Goldstein) 4. Introduction to Experimental psychology (Milagros M. Catabona) 5. General psychology (Alicia H. Kahayon, Gaudencio V. Aquino) 6. College of Science, Pennyslvania University (2007) 7. The parameter of Emotion, 3rd edtion 1998 8. New York University (Seymour Solomon) Dean, Arts and sciences. 9. Handbook of Infant Perception: From sensation to perception ( Philip Salapatek, Leslie B. Cohen) 10. Introduction to psychology 3rd edition (Alicia S. Bustos, Natividad Malolos, Angelina Ramirez, Exaltacion Ramos, Ma. Alicia Bustos-Orasa)