Pavlov State Medical University of St. Petersburg
Department of Psychiatry
Psychology, part 1,
course for foreign students
St. Petersburg
2003
The text of this course is compiled by assistants V.R. Piotrovskaia M.D., Ph.D., E.R. Isaeva, Ph.D. and professor V.I. Krylov, the Department of Psychiatry of Pavlov State Medical University of St. Petersburg.
Editor: professor N.G.Neznanov.
Reviser: T.V. Sokolovskaia, Dr. of Psychology, reader at the Department of Medical Psychology of St. Petersburg Medical Academy of Postgraduate Education.
The Contents:
The main topics:
1.The subfields of psychology.
2.Biological, psychodynamic, humanistic, cognitive and behavioral approaches.
3.The main goals of research in psychology.
4. Some research methods.
Psychology is the science of behavior and mental processes. This means that psychologists use the methods of science to investigate all kinds of behavior and mental processes, from the activity of a single nerve cell to the social conflicts in a complex society, from the development of language in childhood to the adjustments required in old age.
Like other sciences, psychology has developed numerous subfields or areas of specialization. This subfields approach behavior and mental processes in somewhat different ways.
Biological psychology In compliance with Bernstein D.A. “psychologists who analyze the biological factors in behavior and mental processes are called biological psychologists. Some biological psychologists explore the chemical interactions within and between nerve cells, especially in the brain and spinal cord. Some researchers explore the relationships between brain activity and behavior. For example, they might map the parts of the brain that become activated when people solve problems or confront unexpected events. Other biological psychologists look for reasons to how hormones influence emotions and behavior”.
Experimental and cognitive psychology.
Wilhelm Wundt, William James, Edward Titchener, and other early psychologists used the term experimental to distinguish their experiments on human perception, learning and memory, from attempts of philosophers and others who thought hard about such phenomena but performed no experiments. The scientific methods of experimental psychology are now evident in research in every subfield of psychology.
Cognitive psychologists aim their research toward ever more detailed analysis of mental processes involved in learning, memory and perception. They explore the processes underlying judgment, decision making, problem solving, imagination and other aspects of complex human thought or cognition.
Personality psychology
Personality psychologists focus on the characteristics that make us unique. They also try to identify the specific ways in which people differ , to explore the relationships between people’s personalities and their tendency to think, act and feel in certain ways.
Social psychology
The topics studied by social psychologists are: social perception and impression formation, aggression, the formation and change of attitudes, sex roles, and conformity, and social influence.
Clinical psychology.
Clinical psychologists, using tests, interviews and observation, seek to understand and correct abnormal functioning. They study typical alterations of perception, thinking, memory, attention, emotions in the cases of mental disorders and internal diseases. They use similar methods to pinpoint emotional conflicts and adjustment problems and offer individual correction to help solve those problems. The clinician psychology may conduct psychotherapy in private practice or in hospitals, prisons, or institutions for mental retarded persons.
Developmental psychology
Developmental psychologists describe those changes, trying to understand their causes and exploring their effects. They have conducted research on the stress of adolescence and the changes with old age. But because changes in language, thinking, social skills, and personality occur most dramatically in infancy and childhood, much developmental research has focused on those early stages of life. Other research has helped launch special educational programs for preschoolers who appear likely to be at a disadvantage when they start school.
Quantitative psychology.
Quantitative , or measurement psychologists develop and apply mathematical methods for summarizing and analyzing data. They have helped biological psychologists find precise mathematical ways of describing the changes in a subjects mental processes .Some of these methods are known as statistical analyses. Quantitative psychologists are also involved in constructing and evaluating paper-and-pencil tests used to measure traits, attitudes, mental capacity, and mental disorders.
Psychological Approaches.
The biological approach
This approach begins with the assumption that biological factors, such as genetics, electrical and chemical activity in the brain, and the actions of hormones are the most important determinants of behavior and mental processes. Those who adopt this approach study emotions, mental disorders, memory, thinking, and other psychological phenomena by seeking out and learning about their biological components.
The psychodynamic approach
The psychodynamic approach was founded by Sigmund Freud. The psychodynamic approach presumes that behavior and mental processes reflect constant, dynamic, and often unconscious struggles within each person. These struggles are varied and complex, thus they usually involve conflict between the impulse to satisfy instincts or wishes (for food, sex, or aggression, for example) and the restrictions imposed by society.
The behavioral approach
American psychologist John Watson studied only what he could observe directly, but not unobservable mental events. By focusing on observable actions alone, said Watson, psychologists would not have to rely on people's possibly distorted reports about mental processes and could begin to understand behavior whether it occurs in adults, children, the mentally ill, or animals. Watson’s views gave birth to the behavioral approach to psychology. According to this approach, the pattern of rewards and punishments that each person has experienced determines most behaviors and ways of thinking
The humanistic approach
A fundamental assumption of the humanistic approach is that people control themselves. Furthermore, according to this approach, each person has an innate tendency to grow toward his or her own potential, although the environment (including other people) may block this growth or stimulate it.
According to the humanistic perspective, behavior is determined primarily by each person's capacity to choose how to think and act. These choices are dictated by each individual's unique perception of the world. If you perceive the world as a supportive, friendly place, you are likely to feel happy.
The cognitive approach
In the last fifteen years the cognitive approach - has become particularly influential. The cognitive approach emphasizes the importance of thoughts and other mental processes. This perspective focuses directly on mental processes - that is, on how the brain takes in information, uses its functions of perception, memory, thought, judgment, decision making and the like to process that information and generates integrated patterns of behavior.
The question of which of these approaches is the "right" one can never be answered simply because "tightness" or "wrongness" is not at issue. Each approach to psychology emphasizes a particular set of factors that tells part of the story of behavior and mental processes.
The goals of research
The basic goals of research are description, prediction, control, and explanation.
Description
Accordingly to Bernstein D.A.”… in order to answer any research question, the psychologist must first describe the phenomenon of interest, gather detailed information about case, measure and summarize data before aiming for more ambitious goals . Such descriptive data are usually collected through surveys, case studies, and observations”.
Prediction
Noticing interesting patterns and apparent relationships, psychologist might aim for a more ambitious research goal: prediction.. When a prediction is stated as a specific, testable proposition about a phenomenon, it is called a hypothesis. To test his hypothesis, psychologist would gather additional data, looking not only for evidence that supports the hypothesis but also for evidence that refutes it. In research aimed at prediction, one tests hypotheses by analyzing descriptive data in order to detect relationships between variable. Variables are specific factors or characteristics that can vary in some way. The relationships detected in prediction-oriented research usually appear as correlations. Correlation means the degree to which one variable is related to another.
Control
A scientist trying to describe or predict data , might find it difficult to choose among a number of hypotheses if he will use only correlational methods. The psychologist might aim for another goal: control. A scientist would try to establish a situation in which factors that might interfere with an understanding of the cause-effect relationship are eliminated.
The procedure when we can manipulate one variable and observe its effect on another variable, we call the result controlled research. Controlled research involves experimental methods, controlled experiments can also be conducted in the "real world" .
Explanation
Scientists can begin to suggest-explanations after examining data from descriptive, predictive, or controlled research (usually all three). Explanations often include or lead to the formation of general rules about certain categories of behavior or mental processes. These general rules are organized into a theory, which is an integrated set of principles that can be used to account for, predict, and even control certain phenomena. Some explanations in science are so well established that they become known as laws.
Research metods
Specific methods used to conduct research include surveys, case studies, naturalistic observations, and experiments.
Survey methods involve giving people questionnaires or special interviews
designed to obtain descriptions of their behavior, attitudes, beliefs, opinions, and intentions. For example, surveys in psychological research have helped clarify differences in the ways people from different social classes discipline their children (lower-class families tend to be more strict). Usually survey data lead psychologists to formulate predictions and testable hypotheses and to test those hypotheses through additional correlational and experimental research.
A case study is an intensive examination of some phenomenon in a particular individual, group, or situation. Case studies are especially useful when a phenomenon is very complex or relatively rare. The use of case studies has a particularly long tradition in clinical psychology. Freud’s development of psychoanalysis, for example, was based on case studies of “neurotics” whose other physical symptoms disappeared when they were hypnotized or asleep. Case studies have one major limitation, however: cases are not necessarily representative samples.
Sometimes the best way to gather descriptive data about a psychological phenomenon is to observe it as it occurs in the natural environment. This is especially true when other approaches are likely to be disruptive or misleading.
Clinical psychologists use naturalistic observation to gather information about a person’s problematic behavior in preparation for changing it. Similarly, industrial-organizational and engineering psychologists observe how groups or equipment function before they suggest changes
Experiments are arrangements in which the researcher manipulates or controls one variable and then observes the effect of that manipulation on another variable. The variable controlled by the experimenter is called the independent variable. The variable to be observed is called the dependent variable because it is affected by or depends on the independent variable.
The group that receives the experimental treatment is called the experimental group. The people who receive no treatment are called control group. The process of selecting subjects for any experiments is called sampling.
In order for an experiment’s results to reveal something about people in general, the researcher chooses subjects who are representative of people in general. When every member of the population has an equal chance of being chosen for study, the individuals selected constitute a random sample. If not everyone in a population has an equal chance of being selected the sample is said to be a biased sample.
Confounding variables confuse or confound interpretation of an experiment’s results. Any factor that might have affected the dependent variable along with or instead of the independent variable, may be a confounding variable. When confounding variables are present, the investigator cannot know which variable was responsible for the results - the one that was manipulated or the confound.
Results can also be confounded by the basic design of an experiment. When medical and psychological treatments are evaluated, improvement stemming solely from the subjects’ knowledge and perceptions of those treatments is usually called the placebo effect. A placebo is a treatment that contains no active ingredient but nevertheless produces an effect because a person believes it will have that effect. Patients may improve after they are given a new drug, not because the drug contains an effective treatment for their illness, but because they believe that the drug will help them.
A fourth potential confound comes from experimenter bias, the unintentional effect that experimenters may exert on results. To prevent experimenter bias from confounding results, experimenters use a double-blind design, in which both the subjects and those giving the treatments are unaware of, or “blind” to, who is receiving a placebo. Only the director of the study - a person with no direct contact with the subjects - knows who is in the experimental group and who is in the placebo group.
Questions and tasks on the main topics.
1.What is the psychology science?
2.What are the main psychology topics ?
3.What psychological approaches are used in psychological studies?
4.Name the main theoretical approaches used in psychology.
5.What are the main goals of psychological research?
6.What research methods are used by the psychologists ?
The main topics.
1.Sensory system, problem of coding, representing stimuli in the brain.
2.Touch and temperature.
3.Pain
4.Perception, its futures, organization, constancy.
5.Depth perception.
6 Perceptual illusions.
A sense is a system that translates data from outside the nervous system into neural activity, giving the nervous system, especially the brain, information about the world. For example, vision is the system through which the eyes convert light into neural activity that tells the brain something about the source of the light (for example, that it is bright) or about objects from which it is reflected (for example, that a round, red object is out there). These messages from the senses are called sensations and comprise the raw information that affects many kinds of behavior and mental processes . Psychologists have distinguished between sensation - the initial message from the senses - and perception, or the way the message is interpreted and given meaning in terms of previous experiences. Thus, you do not actually "sense" a cat lying on the sofa; you see shapes and colors - visual sensations. But, because of your previous knowledge of the world, you interpret or perceive these sensations as a cat.
Steps in Sensation
The first step in sensation involves accessory structures, which modify the stimulus. For example: 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 - the process of converting incoming energy into neural activity. As a radio receives energy and transduces it into sounds, the ears receive sound energy and transduce it into neural activity that people recognize as voices, music and other auditory experiences. Transduction takes place at structures called receptors, cells that are specialized to detect certain forms of energy. Than sensory nerves transfer the receptor’s activity to the brain. For all the senses but smell, the information is taken first to the thalamus, which relays it to the cerebral cortex.
Each nerve cell that carries sensory information responds to only a small part of the incoming energy. This portion of the world that affects a given neuron is its receptive field.
The Problem of Coding
Coding is the translation of a stimulus's physical properties into a pattern of neural activity that specifically identifies those physical properties. If you want the brain to see the sundae, you should probably stimulate its optic nerve (the nerve from the eye to the brain) rather than its auditory nerve (the nerve from the ear to the brain). This idea is based on the doctrine ofspecific nerve energies: stimulation of a particular sensory nerve provides codes for that one sense, no matter how the stimulation takes place.
Representing Stimuli in the Brain
Sensory systems transfer information to the brain and they also organize that information. This organized information is called a representation. Accordingly to Bernstein D.A. “…in humans, representations in the cerebral cortex of vision, hearing, and the skin senses share the following features:
1. A primary area of sensory cortex receives information through the thalamus from each of these senses.
2. The representation of the sensory world in the cortex is contralateral to the part of the world being sensed. Thus, for example, the left side of the primary visual cortex "sees" the right side of the world, and the right side of the somatosensory cortex "feels" the left side of the body. This happens because nerve fibers from each side of the body cross on their way to the thalamus.
3. The primary cortex contains a map or topographical representation of each sense. This means that any two points that are next to each other in the stimulus will be represented next to each other in the brain. The proportions on the sensory map may be distorted, but the relationships among the various points are maintained.
4. The density of nerve fibers at any given part of a sense organ determines the extent of its representation in the cortex. For example, your fingertips, which have many receptors for touch, have a larger area of cortex representing them than does the skin on your back.
5. Each region of primary sensory cortex is divided into columns of cells that have similar properties. For example, one column of cells in the visual cortex might respond most to diagonal lines; another column might respond most to edges.
6. For each of the senses regions of cortex other than the primary areas do more complex processing of sensory information. Called association cortex, some of these areas contain representations of more than one sense; others provide additional representation areas for a given sense. Hearing, for example, is represented in several association areas”.
Thus, sensory systems convert some form of energy into neural activity. Often the energy is first modified by accessory structures; then a sensory receptor converts the energy to neural activity. The pattern of neural activity codes physical properties of the energy. The codes are modified as the information is transferred to the brain and processed further.
SOMATIC SENSES AND THE VESTIBULAR SYSTEM
As we know, some senses are not located in a specific organ, such as the eye or the ear. These are the somatic senses, also called somatosensory systems, which are spread throughout the body. The somatic senses include the skin senses of touch, temperature, and pain, and kinesthesia, the sense that tells the brain where the parts of the body are. It is not strictly a somatosensory system, the vestibular system will also be considered in this section because its function - telling the brain about the position and movements of the head - is closely related to kinesthesia.
Touch and Temperature
Touch is vitally important . A person without touch would have difficulty surviving. Without a sense of touch, you could not even swallow food.
The stimulus and receptors for touch The energy detected and transduced into neural activity by the sense of touch is a mechanical deformation of tissue, generally the skin, frequently by stimulation of the hairs on the skin.
Fingertip touch is the main way we explore the textures of surfaces. It can be extremely sensitive, as is evident not only in sensual caresses but also in the speed with which blind people can read Braille. The mouth, especially the lips, also has many touch receptors . For infants and young children, who have not developed the ability to coordinate hand movements, the sense of touch in the mouth is an important way of learning about the world.
Adaptation of touch receptors. Sensibilisation.
The touch sense focuses changes and filters out excess information through adaptation - the process through which responsiveness to a constant stimulus decreases over time. A touch nerve responds with a burst of firing when a stimulus is applied, then quickly returns to baseline firing rates, even though the stimulus may still be in contact with the skin. If the touch pressure increases, the nerve again responds with an increase in firing rate, but then it again slows down. A much smaller number of nerves adapts more slowly, continuing to fire at an elevated rate as long as pressure is applied to the skin.
The increasing sensitivity after training receptors and as a result of its relations is called sensibilisation.
Pain
A change in the intensity of the same kind of stimulation can create a distinctly different sensation: pain. Pain provides you with information about the impact of the world on your body; it can tell you: "You have just crushed your left thumb with a hammer." Pain also has an aversive emotional component.
It is still unknown about how pain is created, but it appears that painful stimuli damage tissue and cause the release of bradykinin. Bradykinin fits into specialized receptors in pain nerves, causing them to fire.
Pain signals are carried from the skin to the spinal cord by A-delta fibers (carry sharp pain), and (C fibers carry several types of pain, including chronic, dull aches). These same C fibers also respond to no painful touch, but with a different pattern of firing. Both A-delta and C fibers carry the pain impulses into the spinal cord, where they form synapses with neurons that carry the pain signals to the thalamus and other parts of the brain.
Modulation of pain: The gate theory
The nervous system has several mechanisms for controlling the experience of pain. The gate theory explain how the nervous system controls the amount of pain that reaches the brain . It holds that there is a functional "gate" in the spinal cord that either lets pain impulses travel upward to the brain or blocks their progress. This gate can be closed by two mechanisms.
First, impulse from skin senses can come into the spinal cord at the same time the pain gets there and can "take over" the pathways that the pain impulses would have used. Thus, nonpainful and painful sensations coming into the spinal cord in effect compete for pathways to the brain. That’s why rubbing the skin around a wound reduces the pain you feel and electrical stimulation of the skin around a painful spot relieves the pain.
Second, the brain can close the gate by sending signals down the spinal cord. These messages from the brain block pain signals when they synapse in the spinal cord. Finally it isanalgesia, the absence of the sensation of pain in the presence of a normally painful stimulus.
Proprioception
The sensory systems receive information from the external world, such as the light reflected off green grass or the feeling of cool water washing over your feet. But as far as the brain is concerned, the rest of the body is "out there" too, and we know about where we are and what each part of our body is doing only because sensory systems provide this information to the brain. These sensory systems are called proprioceptive ("received from one's own").
The sense that tells you where the parts of your body are with respect to each other is kinesthesia. You do not think much about kinesthetic information, but you definitely use it. Even though, with your eyes closed, you can usually do a decent job of touching two fingers together in front of you. To do this, you must know where each finger is with respect to your body. You also depend on kinesthetic information to guide all your movements. Otherwise, it would be impossible to develop or improve any motor skill, from basic walking to complex athletic movements
Kinesthesia also plays an important role in a person's sense of self. Normally, kinesthetic information comes from both muscles and joints. Receptors in muscle fibers send information to the brain about the stretching of muscles, although their main role is to control muscle contraction . The primary source of kinesthetic information comes from joint receptors. These are nerve endings similar to those in the skin, but they are located where two bones meet, and they respond to deflections of the joint. When the position of the bones changes, joint receptors transduce this mechanical energy into neural activity, providing information about both the rate of change and the angle of the bones. This coded information goes to the spinal cord and is sent from there to the thalamus along with sensory information from the skin. It goes to the somatosensory cortex and to the cerebellum , which is involved in the coordination of movements.
The vestibular sense tells us about the position of the body in space and about its general movements. It is often thought of as the sense of balance. We usually become aware of the vestibular sense only when we overstimulate it and become dizzy. Two vestibular sacs and three semicircular canals which are part of the inner ear are the organs for the vestibular sense. The vestibular sacs are filled with fluid and contain small crystals called otoliths ("ear stones") that rest on hair endings. Because gravity pulls the otoliths toward the earth, they shift when the head tilts, stimulating the hair endings and providing information to the brain about the position of the head with respect to the earth.
The semicircular canals give information that is independent of the earth. They are fluid-filled, arc-shaped tubes that are oriented in three different planes. Tiny hairs extend into the fluid in the canals. Whenever the head moves or changes its rate of movement in any direction, the fluid in at least one of the canals moves, bending the hairs. This bending stimulates neurons that travel with the auditory nerve, signaling to the brain the amount and direction of head movement.
The vestibular system has neural connections to the cerebellum, to the part of the autonomic nervous system that affects the digestive system, and to the muscles of the eyes. The connections to the cerebellum help coordinate bodily movements. The connections to the eye muscles create vestibular-ocular reflexes.
FROM SENSATION TO PERCEPTION:
Perception is the psychological process through which sensations from the environment are transforming. Using knowledge and understanding of the world perception create ourmeaningful experiences.
Some Features of Perception
There are six features of perception. First, perception is generally knowledge based. Second, perception is often inferential. People do not always have complete sensory information at hand, but the perceptual system uses people's knowledge or make inferences about what they may not be able to hear, see or feel. Third, perception is categorical; it allows people to place apparently different sensations in the same category based on some common features.
Fourth, relational feature of perception. Fifth, perception is adaptive, allowing people to focus on the most important information for handling a particular situation. This aspect of perception helps us to identify quickly stimuli associated with food or other desirable goals, as well as those that are likely to be dangerous.
And finally, many perceptual processes operate automatically.
Absolute Thresholds
The simplest perceptual categorization involves deciding whether a stimulus is present. This process begins with and depends on the sensory receptors and raw sensations.
The minimum detectable amount of light, sound, pressure or other physical energy is called the absolute threshold. This threshold can be amazingly low. Normal human vision, for example, can detect the light equivalent to a single candle flame burning on a dark night thirty miles away!
An area that study the relationship between the physical energy of environmental stimuli and the conscious psychological experience those stimuli produce has a name psychophysics. There is a typical experiment on the absolute threshold for vision. In a laboratory the lights are turned out. After the subject's eyes have adapted to the darkness, many brief flashes of light are presented one at a time at varying intensities, from less than that of a candle burning thirty miles away to levels considerably higher. Each time the subject is asked if the stimulus was seen. The pattern of “ yes” or “no” responses to the varying light intensities usually forms a curve.
The exact amount of energy corresponding to any particular person's absolute threshold cannot actually be determined. Psychophysicists have redefined the absolute threshold as the minimum amount of energy that can be detected 50 percent of the time.
Principles of Perceptual Organization
There are two basic principles of perceptual organization - figure and
ground perception and grouping.
Figure and ground. Looking at a complex visual scene or listening to a noisy environment, our perceptual apparatus automatically picks out certain objects or sounds to be figures (that is, the features to be emphasized) and relegates others to be ground (that is, background).
Grouping Certain inherent features of stimuli lead people to group them together, more or less automatically, into coherent objects or sounds.
Certain parts of the perceptual world become figure and others become background.
In the beginning of twentieth century, a group of German psychologists argued that people perceive sights and sounds as organized wholes. These wholes, they said, are different from and more than just the sum of the individual sensations. Because the German word meaning roughly "whole figure" is Gestalt, these researchers became known as Gestalt psychologists. They proposed six principles that lead the perceptual system to connect sensations together in particular ways, organizing it in patterns. These principles are:
1. Proximity The closer objects are to one another, the more likely they are to be perceived as belonging together.
2. Similarity Similar elements are perceived to be part of a group. People wearing the same school colors at a stadium will be perceived as belonging together even if they are not seated close together.
3. Continuity Sensations that appear to create a continuous form are perceived as belonging together.
4. Closure People tend to fill in missing contours to form a complete object.
5. Orientation When basic features of stimuli have the same orientation (such as horizontal, vertical, or at an angle), people tend to group those stimuli together. Thus, you group the vertical lines of a grove of standing trees together and see those trees separately from their fallen neighbors in the undergrowth.
6. Simplicity People tend to group stimulus features in a way that provides the simplest interpretation of the world .
Perceptual Constancy
Perceptual constancy means that the perception of objects as constant in size, shape, color, and other properties despite changes in their retinal image. Without this aspect of perception, the world would be an Alice-in-Wonderland kind of place in which objects continuously changed their properties. Perceptual constancy includes : size constancy, shape constancy, and brightness constancy.
Depth Perception: Experiencing the Third Dimension
Perception of distance, or depth perception, allows people to experience the world in three-dimensional depth, not as a two-dimensional movie. There are two reasons why we perceive the world in three-dimensional depth. The first involves a wide variety of cues provided by the environment. The second is a set of properties of the visual system itself. The cues provided by the environment includes: the principle of relative size (objects producing larger images on the retina are perceived as closer than those producing smaller ones) , interposition ( closer objects block one's view of things farther away). Greater distances usually produce less clarity. Reduced clarity is interpreted as a cue for greater distance. The effect of clarity on perceived distance explains why a mountain viewed on a hazy day appears to loom larger than the same mountain on a clear day.
Two another stimulus cues for depth come from gradients, which are continuous changes across the visual field. A textural gradient is a graduated change in the texture, or "grain," of the visual field. The second gradient cue is the movement gradient, which is the graduated difference in the apparent movement of objects. Faster relative movement across the visual field indicates less distance. For example, you are riding in a car in an open area, look out the side window at an object of intermediate distance (for example, a house). The telephone poles and other objects closest to you will appear to fly across your visual field at a rapid rate; in contrast, distant trees may seem motionless or even appear to move along with you. This difference in relative movement provides cues to the difference in distance.
Cues based on properties of the visual system
Each human eye is located at a slightly different spot on the head and each eye receives a slightly different view of the world. The difference between the two retinal images of an object is called binocular disparity and is responsible for creating the experience of a solid, three-dimensional object. For any particular object, this disparity decreases with increasing distance. With both eyes open, the brain combines the two images, processes information about the amount of disparity and the distance, and generates the impression of a single object having its correct depth, as well as height and width. Binocular disparity is one of the strongest cues of depth perception.
The final depth cue based on the anatomy of the eye. It is related to fact that the lens of the eyeball changes shape or accommodates. Muscles surrounding the lens must either tighten to make the lens more curved for focusing on close objects or relax to flatten the lens for focusing on more distant objects. Information about the muscle’s activity is relayed to the brain, and this accommodation cue helps create the perception of distance.
Perceptual Illusions
The perceptual attributes we have described constantly and automatically convey precise information about the features of a multitude of objects and surfaces. But this information can distorts. Distorted perceptions can come about through sleep, hypnosis, drugs, and other circumstances; here we are concerned with those distortions of reality known as perceptual illusions. The best-known and most studied perceptual illusion is the Miiller-Lyer illusion. Of the two arrow shafts ( in the Figure 1 a ), the one on the left seems shorter, despite the fact that the two are of equal length. The convergence of the arrowheads on each side of the shaft on the left makes the shaft appear to be the closest part of the scene (like the outside corner of the house in Figure 1 b), whereas the divergence of the arrowheads on the right makes that shaft seem to be toward the back.
Attractive and simple as the depth perception theory of the Muller-Lyer illusion may seem, it cannot account for some phenomena. A striking example is shown in Figure 1 c. In this figure there are no converging lines to suggest
Fig. 1. Variations on the Muller-Lyer illusion. Source: J.M. Darley et all Psychology, 1981.
distance, and the figure does not give a feeling of three-dimensionality; yet it does create a misjudgment of distance like that in the Muller-Lyer illusion. Object is based on the "frame" of which it is a part. When the frame is perceived as larger, as it is in the right side of Figure 1, c, so is the line segment included within it (Rock, 1977 ).
In short , since perception is based on many principles, it seems reasonable that illusions could reflect the violation of more than one of them. Alterations of perception may also be created not by cues provided by the environment, but by the same factors that create response bias in detecting stimuli: motivation, experience, bias, and expectancy.
Questions and tasks on the main topics.
1.What are the processes of sensation and perception?
2.What are the main features of perception?
3.Name the main principles of perceptual organization and characterize them.
4.How do we gain experience the third dimension?
The Main Topics.
1.Selective attention
2.Focused and divided attention.
Attention is the process of directing and focusing certain psychological resources, usually by voluntary control, to enhance information processing, performance, and mental experience. For example, in order to read this page, you focused a psychological resource when you shifted your attention from the television, the newspaper or whatever else you were paying attention to earlier. And you will do it again, should you shift from reading to listening to a nearby conversation (even though your eyes may remain fixed on the book).
Attention is selective, it focus on some stimuli while ignoring others. Stimuli that have certain properties tend to attract attention. Characteristics of stimuli that may attract attention include large size, high intensity, contrast, and novelty.
Focused and Divided Attention. Look at the list of words in Figure 2.. Color the words in different colors which will distinguish from the real meaning of the word ( blue in green color ). Now read the list and say aloud, as fast as you can, the color of the ink in which each word is printed.
Blue Green
Green orange
Purple orange
Red red
Grey blue
Fig. 2
This simple task illustrates two facts about attention.
First - it is all too easy to lose the focus of attention on one particular stimulus or stimulus aspect when another aspect is also attention getting. In this case, two competing stimulus aspects are color and the meaning of a single word.
Second - it may be very easy to divide attention between two stimuli or aspects of stimuli, especially if they are physically close or similar. Thus, the difficulty of the task lies in the fact that you are perceiving both the meaning of the word and its color at the same time, but must try to ignore one stimulus aspect. Whereas attention may be divided between two aspects of a single stimulus, it is not so easy to divide attention between very different stimuli or between different tasks. This limitation can be inconvenient, as when you try to watch television and have a conversation at the same time.
The ability to divide attention between visual events is also limited. In one experiment, for example, people watched a screen on which two video games were superimposed. When they were told to focus attention on the stimuli in one of the games, they became totally unaware of events in the other game .The beam of attention was not wide enough to capture two visual stories taking place at the same location.
The ability to divide attention is not entirely fixed. It depends in part on how much people practice doing it, what kind of simultaneous stimuli are present, and the amount of stress involved.
Practice People who are experienced at dividing their attention do better at it than novices. Experience helps because extensive practice allows a person to process and act on perceptual information so automatically that the practiced task requires little attention.. Obviously, it is easier to divide attention between two sets of stimuli when one of them no longer requires much attention in order to be perceived and processed.
Nature of the stimuli In general, the closer together two stimuli are, the more easily they can be perceived at the same time. Dividing attention is also easier when the stimuli do not compete for attention through the same sensory system, because the human brain appears to have more than one pool of attentional resources and more than one spotlight of attention. Having different attentional resources is a little like having an extra person available to help out when there is more than one job to do at the same time. However, each spotlight of attention tends to focus on a particular sensory channel. Thus, if two sets of stimuli (say, a light and a sound) involve different senses, people can more easily perceive them at the same time than if both are visual or auditory and thus have to compete for the same resources.
This is one reason why skilled secretaries can type and shadow efficiently at the same time: typing requires visual perception and movement of the fingers and hands, whereas shadowing requires auditory perception and vocal responses. Somewhat different attentional resources are used in each task.
Questions and tasks on the main topics
1.What problems are studied in psychophysics ?
2.Give the full description of attention?
The main topics:
1.Preliminary distinctions.
2.Encoding, storage, retrieval.
3.Working and long-term memory.
4.Decay.
Memory is the way we record the events of our lives and also the information and skills we glean from these events.
This capacity is necessary for humans or any other animal. Without memory, there would be no experience, no learning, no ability to build or hone skills, no recall of names or recognition effaces, no reference to past days or hours or even seconds. This feeling of personal identity is necessarily based upon a continuity of memories that links our yesterdays to our todays.
Studying Memory .
In compliance with Gleitman H. “… the first step is to realize that memory is not a single entity and that there is no single set of memory processes. Instead, the term memory is a blanket label for a large number of processes that work together to create a bridge between our past and our present”.
We use our memories to connect a wide range of time intervals. Sometimes, we need to remember something we learned just moments ago; in some cases, we draw on knowledge gained months or even years earlier., on other occasions we are asked to recall material that has never been out of our thoughts: for example you hear a bit of news, continue to think about it for a while, and then, without interruption, are asked to report what you had heard.
These different retention intervals are served by different memory systems. Information learned long ago is stored in long-term memory. This memory system allows materials to lie in memory for long periods of time. Other information is stored in working memory. This is the memory system that stores information we are working on right now.
When we search our memories for particular fact, we are using episodic memory - a memory for a specific event. When we must remember how to combine words to form sentences we use our generic memory. Generic memory is our mental library - it holds our mental dictionary and is also the storehouse for all our commonsense knowledge. When searching for the answer to “What did you have for dinner last night?” we are dealing with explicit memory. Sometimes, though, we are influenced by the past without our realizing it at all. Implicit memory is the sort of memory without awareness. Thanks to this memory we regard sentences we have heard before.
Encoding, Storage, Retrieval
The act of remembering implies success at four aspects of the memory process.
First is the acquisition. In order to remember, one must have learned. For example, imagine meeting someone at a party, being told his name, and moments later realizing that you no longer know it! This experience is probably not the result of ultra-rapid forgetting. Instead, it is likely to stem from a failure in acquisition: You were exposed to the name but barely paid attention to it and, as a result, never learned it in the first place.
Another memory process is encoding. The term encoding refers to the form in which an item of information is to be placed in memory. Thus, a physician learning about a new medication might focus on its uses, without giving much thought to its side effects. Or she might focus on the biochemical mechanisms through which the drug works, without thinking about how a patient’s life might be improved by it. Such differences in emphasis during encoding can have a profound effect on how (or whether) this information will be remembered later.
The next aspect of remembering is storage: To be remembered, the encoded experience must leave some record in the nervous system (the memory trace).
The final phase is retrieval, the point at which we try to remember. One way to retrieve material is through recall. This refers to our efforts to supply information from memory in response to a specific cue or question. Trying to answer questions like “What was the name of that medicine you learned about last year?” or “Can you remember where you read about that new medicine?” all require a different recall. A different way to retrieve information is through recognition. In this kind of retrieval, we are presented with a name, fact, or situation and asked if we’ve encountered it before. “Was the medicine perhaps called ‘Coaxil’?” would be a question requiring recognition.
Encoding, Stage theory of Memory
H. Gleitman also wrote that “… the stage theory of memory asserts that there are several storage systems, each with different properties. Working memory holds information for short intervals - that is, while we are working with it. Long-term memory, in contrast, stores materials for much longer, sometimes for as long as a lifetime”.
The long-term memory has enormous capacity : The average college student remembers the meanings of 80,000 words, thousands of autobiographical episodes, millions of facts, hundreds of skills, the taste of vanilla and the smell of lemon. All of this and much more art stored in long-term memory.
The capacity of working memory is limited. This capacity has been measured by a memory span task in which the individual hears a series of items and must repeat them in order after just one presentation. If the items are randomly chosen letters or digits or short words, adults can repeat seven items or so without error. With longer series errors are likely. This has led to the assertion that working memory’s capacity is seven items, give or take one or two.
The stage theory asserts that the road to long-term memory necessarily passes through working memory. Working memory can be regarded as a loading platform, sitting at the entrance to the huge long-term storage.
Working memory has a limited capacity: It can handle only a small number of packages at any one time. However, what these packages contain is, to a large extent, up to us. We can squeeze more information into the same number of memory units.
Recoding into larger chunks As an example, when we try to call a series of digits that he heard only once:
136162536596481
he treats this as a series of fifteen unrelated numbers, we will almost surely fail. But if we recognize that the digits form a pattern, specifically
1 36 16 25 36 59 64 81
our task becomes much easier. We only have to remember the underlying relationship, “the squares of the digits from 1 to 9,” and the fifteen components of the series are easily recreated.
In this task, the person repackages the material to be remembered, recoding the input into larger units that are often called chunks. This is crucial because working memory’s capacity appears to be measured in chunks, rather than in bits of information. In general, working memory seems able to hold seven plus-or-minus two chunks. If each chunk contains only a single figure, then working memory can hold roughly seven figures. If each contains a couple of figures (16,64 and so on), then working memory can hold fourteen figures (two figures per chunk) or seven chunks. The more information we jam into each chunk, the more information can be stored.
Much of the receding of memory items, or chunking, happens quite automatically . According to the storage theory when an item is repeated over and over again, it can be held in working memory, and this increases the probability that the item will be transferred to long-term storage. But it is not exactly so.
The entering long-term memory is not this automatic and depends on more than the mere passage of time. Evidence comes from studies of maintenance rehearsal, a strategy that keeps information in working memory but with little long-term effect. As an everyday example, consider what happens when you look up a telephone number. You need to retain the number long enough to complete your call, but you have no need to memorize the number for later use. In this circumstance, you are likely to employ maintenance rehearsal: You repeat the number to yourself while you dial. But what happens if the line is busy? A moment later, you try to dial the number again, but realize you’ve already forgotten it. Maintenance rehearsal kept the number in working memory long enough for you to dial it the first time but failed to establish it in long-term memory. As a result, the number is forgotten after just a few seconds.
Mnemonics
The development of techniques for improving memory processes are called mnemonics (or mnemonic devices). All mnemonics are build on the same base: We remember well what we organized well.
Mnemonics through verbal organization It is easier to remember verbal material if it is organized. Poetry, with word sequences that maintain a fixed rhythm or rhyme, provides one way to achieve this organization, and this fact has been exploited by many cultures at many times. And in modern times verse is still used as an effective mnemonic (“Thirty days hath September April, June, and November”).
Mnemonics based on visual imagery Some of the most effective mnemonics technique is the method of locus, which requires the learner to visualize each of the items she wants to remember in a different spatial location (locus). In recall, each location is mentally inspected and the item that was placed there in imagination is retrieved.
Images are another way of forming chunks in memory, that is why it help. By creating a mental image, two unrelated items are joined and that they form a new pattern . When part of the chunk (the imagined locus) is presented the entire chunk is retrieved, yielding the part required for recall.
During study and learning , we transfer new information from working memory into our long-term store of knowledge. Successful encoding is not enough. It is important be able to retrieve the information when we need it; otherwise, what we’ve learned will be useless to us. The potential difficulty of retrieval is obvious to anyone who has ever “blocked” on a familiar name. We may know the word or name (have encoded and stored it) but be unable to retrieve it when trying to introduce an old friend to a new one. It is because the memory trace is inaccessible. Access to the trace can be restored by an appropriate retrieval cue, a stimulus that opens the path to the memory.
Often retrieval seems effortless: You are asked your middle name and instantly respond. Sometimes, though, retrieval is more difficult, requiring effort and a deliberate search for retrieval cues: You walk out of the shopping mall and can’t remember where you parked your car. But then you recollect that your first stop was at the drugstore, and this seems to trigger the memory of squeezing the car into a narrow space in the lot near the store.
Mnemonics based on associating process In other cases, retrieval initially seems impossible, as though the target information was truly lost. But then some cue is presented and suddenly the memory returns. A return to your home town, for example, after a long absence, may unleash a flood of recollection, as the sights and sounds of the place effectively trigger the relevant memories. A word, a smell, a visit from a school friend not seen for years -any of these may summon memories we thought were utterly lost.
When Memory Fails.
Memory failures have many causes. Some arise from faulty encoding; others arise at the moment of recall. In this section, we will discuss three aspects of memory failure. One concerns the passage of time: Ribot’s law of memory regression formulates the finding that memory for resent events is lost before memory for more remote events. That is why it is easier to remember the recent past than it is to remember events from long ago (Sims A, 1988 ). A second concerns memory error-cases in which events are misremembered, so that the past as recalled differs from the past as it actually unfolded. The third topic concerns memory failure of a more extreme sort, as we consider what happens to memory in certain kinds of brain damage.
It is true that yesterday’s lesson is better remembered than last week’s, and last week’s better than last year’s. The longer time between learning and retrieval - that is, the longer the retention interval - the greater the chance of forgetting.
The theory holds that memory traces simply decay as time passes, like mountains that are eroded by wind and water. The erosion of memories is presumably caused by normal metabolic processes that wear down memory traces until they fade and finally disintegrate.
In compliance with Crowder R.G.(1985) –“… memory is vulnerable to some sort of interference, with the newly arriving information interfering with the previously learned material. It seems that the forgotten material is neither damaged nor erased; it is simply misplaced in our memory.
For example - someone who buys a newspaper each day and then stores them in a large pile in the basement. Each newspaper is easy to find when it is still sitting on the breakfast table; it can still be located without difficulty when it is on top of the basement stack. After some days, though, finding the newspaper becomes difficult. It is somewhere in the pile, but may not come into view without a great deal of searching. And, of course, the pile grows higher and higher every day; hence, interference will increase as the retention interval grows longer”.
Among the different memory phenomena , the special interest concerns repressed memories. Repression has been most discussed in connection with the recovery of traumatic childhood men often memories involving sexual abuse. In these cases, people often report that traumatic memories were pushed out of consciousness - that is, repressed many years, sometimes for as long as two or three decades. The memories than surface much later, often while the person is being treated by a therapist for problem not obviously connected to the alleged childhood events (Holmes, 1990).
Disordered Memories
Anterograde Amnesia. Certain lesions in the temporal cortex (specifically, in the hippocampus and nearby subcortical regions) produce a memory disorder called anterograde amnesia (anterograde means “in a forward direction”). Patients with this disorder often have little trouble remembering events after the injury; their difficulty, instead, is in learning anything new. This kind of amnesia can occur as a result of various brain lesions. Anterograde amnesia is one of the symptoms of Alzheimer’s disease, tragic side effect of neurosurgery undertaken to treat severe epilepsy (Corkin,1984 ) .
Retrograde Amnesia. An another set of deficits occurs in retrograde amnesia (retrograde means “ in a backward direction”). The patient suffers a loss of memory to period prior to the brain injury. A brief period of retrograde amnesia always follows electroconvulsive therapy, a one kind of treatment for severe depression or mania that involves brief electric shocks applied to the head. Patients receiving this therapy have no memories of their treatments or the events directly preceding.
Longer periods of retrograde amnesia, lasting weeks or even years, can result from brain tumors, diseases or strokes. And in many cases, retrograde effects accompany anterograde amnesia.
Questions and tasks on the main topics.
1.Tell about the stage theory of memory.
2.What is the mechanism of working memory and that of long-term memory?
3.How can a great deal of information in working memory be held ?
4.Describe the difference between explicit memory and implicit memory.
5. What kinds of amnesia do you know ?
The main topics.
1.Mental representations.
2.Mental images.
3.Spatial thinking.
4.Knowledge and memory.
5.Solving problems, reasoning and decision making.
In compliance with Gleitman H. “Many of the components of our knowledge can be regarded as mental representations of the world and of our experiences in it. These representations are the main elements of thought.
Psychologists, philosophers, and computer scientists have found it convenient to distinguish between two broad classes of representations, the analogical and the symbolic. Analogical representations capture some of the actual characteristics of (and are thus analogous to) what they represent. In contrast, symbolic representations create no such relationship to the item they stand for. As we will see, human thought uses both kinds of representations. ” Consider a picture of a mouse (Fig.2.). The picture ways quite different from the real animal; the real picture consists of marks on paper, whereas the actual mouse is flesh and blood. The picture represents a mouse rather than actually being one. The picture has many similarities to the creature it represents, so that, in general, the picture looks like a mouse: The mouse's eyes are side by side in reality, and they're also side by side in the picture; the mouse s ears and tail are at opposite ends of the creature, and they're at opposite ends of the
Fig. 2.
picture. It is properties like these that make the picture an analogical representation.
In contrast, the word mouse it is an abstract representation, and the relation between the five letters m-o-u-s-e and the little animal that they represent is entirely arbitrary.
The same situation holds for mental representations. Some of our mental representations are images that reflect more or less directly many of the attributes of the objects or events they represent. Other mental representations are more abstract, much as words in a language.
Mental Images.
Some of our knowledge is based on analogical representations called mental images. We seem to inspect these images with "our mind's eye," and read information from these images much as we would read information off of a picture. Similar claims have been made for other senses - including hearing with the "mind's ear," or feeling with the "mind's fingers." But far more is known about visual imagery than about imagery in these other modalities, and so our focus will be on visual images.
Spatial Thinking
Spatial thinking is closely related to mental imagery , it is the kind that we use when we want to determine a shortcut between two locations or when we mentally try to rearrange the furniture in the living room. Most people have a general conception of the layout of their environment. Accordingly to Jonides and Baum (1978) , part of this knowledge is based on mental maps that have pictorial qualities. For example, students were asked to estimate the distances between various locations on their university campus - between their dormitory and the main building, or between the student union and the library. They were quite accurate in their estimates, but more important was the time it took to provide these estimates. The longer the distance, the longer the estimation time. It was as if the students measured distances with mental ruler on a mental map, much as one might measure the length of a wall with a small ruler.
Other kinds of spatial thinking involve processes that are symbolic , not analogical. In one study research participants were asked to indicate relative locations of Moscow and Tel-Aviv. The participants judged Moscow to be west of Tel-Aviv, although it is actually father east. Similarly, they judged Helsinki to be father north than St. Petersburg. These results suggest that they weren’t biasing there answers on mental maps at all. Instead, they seemed to be reasoning in this fashion: Finland is north of Russia. Helsinki is in Finland. St. Petersburg is in Russia. Therefore Helsinki is north of St. Petersburg.
The knowledge being used in our examples is clearly symbolic, not pictorial. These symbolic formulations can lead to error.
Accordingly to Gleitman H. “…the term concept describes a class or category that includes some number of individuals or subtypes. An example is dog, which includes poodle, livable, dachshund, and Alsatian. Other concepts designate qualities or dimensions. Examples are length and age. Still other concepts are relational, such as taller than. Notice that relational concepts don't apply to any one item in isolation. One can't be taller than except in relation to something else to which one's height is being compared.”
In thinking, we combine concepts in various and sometimes complex ways. Such combination is association - a sense of "this goes with that”. Concepts are what we generally think about. Relationships among concepts, take the form of propositions. These are statements that relate a subject (the item about which the statement is being made) and a predicate (what is being asserted about the subject). Propositions can be true or false. For example, "Tom loves to play the football." "Mary plays soccer," and "Squirrels eat burritos" are all propositions. But just the words "Mary" is not propositions “plays soccer"- also ; the first is a subject without a predicate; the second is a predicate without a subject.
Knowledge and Memory.
When we think, we often form new concepts and formulate new propositions. But many concepts and propositions are already stored in memory, where they constitute our accumulated knowledge, the "database" that sustains and informs our thoughts.
Such database is used generic memory, which is memory for items of knowledge independent of the particular occasion on which one acquired that knowledge. For example, we remember that Paris is the capital of France, that three is the square root of nine, and that sugar is an ingredient of most cookies.
For each person, generic memory contains an extraordinary wealth of know edge, including the meanings of words and symbols, countless facts about the world, what objects look like, and various general principles, schemas, and scripts. Within this huge archive, one of the important components is semantic memory, which concerns the meanings of words and concepts. Our entire vocabulary is in this store: every word, together with its pronunciation, all of its meanings, its relations to objects in the real world, and the way it is put together with other words to make phrases and sentences.
Several investigators have proposed network models of generic memory. In the models, words and concepts are linked through a complex system of relationships, so that it is possible to trace a path through these relationships from or concept to other related concepts. Within these networks, words or concepts are represented by nodes, while the associations between the concepts are indicate by associative links or associative connections.
One hypothesis, proposed early on, was that the network has a hierarchic structure. But the relation between items of information in semantic memory is more complex than the hierarchical model indicates .
Difficulties with the hierarchical model led to the formulation of several alternatives, one of which is the spreading activation model. In this model, concepts are still represented by nodes, with associative links connecting one node to the next. However, this model allows these links to represent many different kinds of relationships, including relationships based on hierarchical position (as in canary-bird) or based on similarity of meaning (apple-orange), or on well-learned associations (peanut butter-jelly).
The Process of Thinking: Solving Problems
As Newell A. and Simon H.A. (1972) had written “… problem solving is not merely goal directed, it is also hierarchical: The effort to solve one problem often creates subproblems, so that one needs to reach certain subgoals on the way toward achieving the main goal. And here, too, means-end analysis is helpful: "I want to get to the store. What's the difference between my current state and my goal? One of distance. What changes distance? My automobile. My automobile won't work. What is needed to make it work? A new battery...." In this case, the initial problem (getting to the store) is replaced by a series of subproblems (e.g., getting the car to work). Or, the larger problem can be replaced with a simpler and more familiarroutine ( dressing, preparing cards or cash, locking the door ). By solving these, one at a time, the larger problem gets dealt with”
So the routine is executed without much thought. In other words it becomes automatic and so is performed with minimal attention. In some circumstances this automaticity can create its own problems.
A striking example of this is known as the Stroop effect, named after its discoverer. To demonstrate this effect, research participants are asked to name the colors in which groups of letters are printed. If the letters are random sequences {fwis, sgbr) or irrelevant words (chair, tape), this task is rather easy. If, however, the letters form color names (yellow, red), the task becomes much harder. Thus, a participant might see red printed in green ink, blue in brown ink, and so on. His task, of course, is simply to name the ink color, and so he should say "green, brown," etc. But in this setting, the participant can't help reading the words, and this produces a strong competing response: He is likely to respond very slowly, because while trying to name the ink colors, he is fighting the tendency to read the words themselves aloud.
Sometimes the solution involves a radical restructuring by means of which a misleading set is overcome. Such restructurings may be an important feature of much creative thinking. Some problems initially seem quite difficult and the problem solver discovers an alternative way to conceptualize the problem, breaking the mental set that inhibited her, and soon after, comes up with the answer. Mental set - means that sometime we are fixed on one approach to task and correspondingly unable to think of the task in any other way. This restructuring of a problem may be quite sudden, experienced as a flash of insight, with an accompanying exclamation of "Aha!" Accounts by prominent writers, composers, and scientists suggest that restructuring often occurs after a period of incubation. The idea here is that the thinker believes she has set the problem aside but is actually continuing to think about it unconsciously. Restructuring may also play a role in humor, which often occurs when an unexpected cognitive organization turns out to make sense after all.
Reasoning and Decision Making
The goals that constitute the problem can vary widely .The further form of problem solving is of special interest. This is reasoning, in which the goal is to determine what conclusions can be drawn from certain premises.
In compliance with Gleitman H. “ …in deductive reasoning, the reasoner tries to determine whether certain conclusions can be drawn - that is, deduced—from a set of initial assertions or premises. According to logicians, the validity of the deduction depends on a small number of rules, framed in terms of certain logical relationships, such as and, or, not, and the like. But do humans follow these rules?”
An example of deduction involves the analysis of syllogisms. Each syllogism contains two premises and a conclusion, and the question is whether the conclusion follows logically from the premises. Two examples of such syllogisms (one valid, one invalid) are:
All A are B.
All B are C.___________
Therefore, all A are C. (valid)
All A are B.
Some B are C.
Therefore, all A are C. (invalid )
In deductive reasoning, we reason from the general to the particular. We start with a general rule ("All people are mortal") and ask how it applies to a particular case ("Pat Smith is a person"). But much of the reasoning we engage in is inductive, in which this process is reversed. Here we reason from the particular to the general. We consider a number of different instances and try to determine - that is, induce -what general rule covers them all.
Induction and deduction both allow us to form new judgments and to form new beliefs.
Questions and tasks on main topics.
1.Name the main classes of representations.
2.Give the example of analogical representation in thinking?
3. What are the elements of symbolic thoughts? Where many of these are stored?
4.What is the procedure of problem solving?
5.What is the way of reasoning?
The main topics:
1. What is intelligence?
2. Measuring Intelligence
3 The Causes of Retardation
4. Strategies and Intellectual Functioning
5. The Cultural Context of Intelligence
The first question we are interested in - is.” What is intelligence?”. Our vocabularies are filled with words that describe different levels and types of intellectual functioning—smart, bright, and clever; dull, slow, and dim-witted. But it is difficult to specify exactly what these terms mean, and attempts at specification often lead to disagreements.
Even psychologists disagree on exactly how intelligence should be defined.
Some researchers pay there attention to the capacity for abstract thinking. Others focus on the ability to acquire new abilities or new knowledge. Anothers highlight the ability to adapt to new situations. And there are no single definition of intelligence that has been accepted by all.
Measuring Intelligence
In 1904, in French minister of public instruction appointed a committee with the task of identifying children who were performing badly in school .
Alfred Binet (1857—1911) suggested a project , pragmatic in its goals and quite optimistic in its tone.
With his collaborator, Theophile Simon, Binet believed that intelligence was a general attribute, existing itself in many different spheres of cognitive functioning. They construct a test that included many subtasks varying in both content and difficulty: copying a drawing, repeating a string of digits, understanding a story, and so on. Their idea was that a person might do well on one or two of these tasks just by luck or by virtue of some specific prior experience. A truly intelligent person would be able to perform well on virtually any task and certainly on all of the tasks in this array. And intelligence could be measured by a composite score assessing how an individual did on all the tasks in this set. The diversity of the tasks would ensure that the test was not measuring some specialized talent but was instead a measure of ability in general.
Binet also believed that intelligence grew as the child grew, and this provided the basis for the test's scoring system. Alfred Binet was primarily interested in assessing children. His tests measured mental age, or MA. The standing of a child relative to her age mates was determined by comparing her MA with her chronological age, or CA, To determine the child's intelligence quotient, or IQ, MA is divided by CA and multiplied by 100. Thus,
IQ=MA/CAX100.
The Binet test was originally meant for children, but demand soon arose for the assessment of adults' intelligence. This led to the development of a test standardized on an adult population - the Wechsler Adult Intelligence Scale, or WAIS.
Different intelligence tests have been developed for various goals: to test children, to test adults; to assess mental retardation.
The Causes of Retardation
What causes retardation? Retardation can be traced to a specific genetic disorder, as, for example, in Down's syndrome or a pattern known as fragile-X syndrome (so-called because it involves damage to the X chromosome). Retardation arises because of a problem that affected the developing fetus - for example, alcohol in the mother's bloodstream or certain diseases during pregnancy, such as rubella. Retardation is the result of problems related to birth itself, including premature birth or temporary oxygen deprivation to the fetus. In other cases it arises from conditions subsequent to birth, such as meningitis or head injury.
This is a diverse set of factors, and, in fact, some have estimated that there are over two hundred causes of mental retardation, each with a specific organic basis. All such cases lead to identifiable problems in the nervous system; they also tend to have other symptoms associated with them, and these symptoms play an important role in the diagnosis of individual cases.
Table ( 1, p.47 ) presents a description of the general level of intellectual functioning at various ages in each of these four categories. Also the table shows that mentally retarded persons do not have to be excluded from useful participation in society.
What is Intelligence?
To determine whether intelligence is one unitary ability or is composed of several unrelated abilities, investigators have looked at the correlations among different subtests. In compliance with Gleitman H. ”…factor analysis of these correlations allows us to extract a measurement of the common factor that seems to be shared among all of these tasks; The author of this technique was Charles Spearman. Spearman argued that this factor is best described as general intelligence, or g. He proposed that g is a mental attribute called upon for any intellectual task, and so individuals with a lot of g have an advantage in every intellectual endeavor. If g is in short supply, the individual will do poorly on a wide range of tasks”.
Differences in the cognitive processes that underlie remembering, problem solving, and thinking are seen as individual differences in intellectual performance One line of inquiry tries to relate Spearman's g to differences in reaction time. Another approach focuses on a sub factor, such as verbal intelligence, and relates it to simple cognitive operations, such as memory look-up times. A third approach emphasizes the more complex cognitive components of the tasks posed by standard intelligence tests, as exemplified in studies of analogical reasoning. A fourth line of inquiry investigates the role of working memory and attention. . In solving an analogy problem, for example, one must keep track of the various terms and of their attributes. One must also remember which relationships have already been examined (and found unsatisfactory), so that one doesn't keep examining the same relationships over and over. All of this requires memory storage, as well as attention, as one focuses on different aspects of the problem and develops new interpretations of it.
This leads to an obvious proposal: Individuals with ample working memory and attention should perform better on analogy tests and also on a wide range of other tasks. Individuals without these capacities will perform worse. To test this suggestion, researchers have developed active-span tasks, procedures designed to assess an individual's ability to store and manipulate different pieces of information simultaneously.
Strategies and Intellectual Functioning
A normal adult can master memory tasks that are generally beyond the reach of a six-year-old, and an important reason for this lies in the strategies the adult uses. Suppose she is asked to memorize unrelated materials, such as the words
tulip plumber tiger sweater lily tailor daisy raincoat monkey butcher zebra jacket.
An adult will do her best to rehearse this list of items and probably will also try to organize the list in some way. For example, she might try rhythmic grouping by, say, repeating the items in threes: "tulip, plumber, tiger . . . sweater, lily, tailor, . . . daisy, raincoat, monkey. ..." Or she might try to organize the list of items into categories, thinking first about the flowers, then the occupations, then the animals. Any of these organizational devices will help her in later tests of recall. A six-year-old, in contrast, is unlikely to have such organizational tricks in her repertoire and so will be less successful at such intellectual tasks.
The use of such strategies also accounts for some of the intellectual differences among adults, with the best evidence coming from extreme differences in ability, such as the differences between adults who function normally and retarded individuals. The evidence suggests, for example, that retarded examinees attack memory tasks with little or no resort to organization. They are less likely to rehearse, to group items in a list, or to show recall clustering by semantic categories . Strategy use also provides part of the reason why the elderly often have trouble in remembering - they fail to use strategies when they first encounter the to-be-remembered materials and so are at a disadvantage later on, when the time comes to remember this material .The same is true for individuals who are depressed; they engage poorly with the to-be-remembered materials during learning, and so have difficulty retrieving them later on.
What is Intelligence? Beyond IQ.
Howard Gardner's concept of multiple intelligences is a different attempt to expand the notion of intelligence. He notes, for example, that some individuals are exquisitely talented in music, even though they seem quite ordinary in other respects. This suggests to Gardner that musical intelligence is separate and distinct from other forms of intelligence. Similar considerations led him to argue for the existence of six specialized "intelligences": linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic and personal intelligence.
Musical ability includes skill in composition and in performance. By bodily-kinesthetic intelligence Gardner refers to the ability to learn and create complex motor patterns as in dancers and skilled athletes. By personal intelligence he refers to the ability to understand oneself and others.
Another argument for Gardner's theory comes from the study of so-called savants (formerly, idiot savants). These are generally profoundly retarded persons who have some single extraordinary talent. Some display unusual artistic talent . Others are "calendar calculators," able to answer immediately (and correctly!) if asked questions such as, "What day of the week was March 17 in the year 1683?" . Still others have unusual mechanical talents or unusual musical skills, for example, effortlessly memorizing lengthy and complex musical works.
We might raise a further concern about Gardner's theory: There is no question that some individuals - whether savants or otherwise - have special talents and that these talents are immensely impressive. However, is it appropriate to think of these talents as forms of intelligence? Or might we be better served by a distinction between intelligence and talent? To put this differently, is being smart a talent in the same sense that being able to play the violin is a talent? The answers to these questions are far from clear, and this makes Gardner's claims difficult to evaluate.
Whatever the ultimate verdict on Gardner's theory, there is no doubt that he has performed a valuable service by drawing attention to a set of abilities that is often ignored and certainly undervalued by our society. Gardner is surely correct in noting that we tend to focus too much on the skills and capacities that help people succeed in school. Whether or not these other abilities are forms of intelligence, they are still abilities to be highly esteemed and, if at all possible, nurtured and developed.
The cultural context of intelligence.
Investigations on practical intelligence and on multiple intelligences point up certain limitations of standard intelligence tests. These limitations become more glaring when trying to assess intelligence in members of other cultures. To begin with, many standard intelligence tests emphasize quick and decisive responses. But not all cultures share Western preoccupation with speed. Indians and Native Americans, for example, place a higher value on being deliberate; in effect, they'd rather be right than quick. In addition, they prefer to qualify, or to say "I don't know" or "I'm not sure," unless they're absolutely certain of their answer. But such deliberations and hedging won't help their test scores; on standard intelligence tests you get more points if you guess .
All of this makes it clear that we have to be very careful in applying intelligence measures. Intelligence tests do capture important aspects of intellectual functioning, but they do not capture all aspects or all mental abilities.
Intelligence-test performance seems to be determined by both environmental and genetic factors. Evidence for the role of genetic factors comes from the fact that the correlation between IQs of identical twins is higher than that for fraternal twins and that this correlation is remarkably high even when identical twins are reared apart. Further evidence for a hereditary contribution comes from adopted children whose IQs correlate more highly with those of their biological than their adoptive parents. Evidence for environmental effects is provided by increases and decreases in the mean IQ of populations whose cultural or educational level has risen or fallen. Environmental effects may also explain a worldwide improvement in IQ scores. A similar point is made by adoption studies that show some correlation in IQ between children and their adoptive parents.
In recent years, much interest (and polemic) has focused on IQ differences among racial-ethnic groups. The mean IQ of American blacks is about 10 to 15 points lower than that of American whites. Some authors have argued that this is in part a consequence of a genetic difference between the two groups. Environmentalists reply that the difference is markedly reduced by various environmental changes such as interracial adoption. A similar point is made by the fact that the mean IQs of children of white German mothers fathered by U.S. soldiers after World War II are just about the same whether the fathers were black or white. It is also supported by the fact that IQ is more closely related to the phenotype of dark skin than it is to the genotype.
Questions and tasks on main topics .
1.What does intelligence test measure?
2. What is the idea of theory of multiple intelligence ?
3.How do researchers study the role of genetic factors in intelligence investigations?
Table 1.Characteristics of the mentally retarded.
Source: Psychology, after H. Gleitman, 1998 p. G38.
The main topics.
1.The James-Lange theory.
2.The attribution-of-arousal-theory.
3 Emotional behavior : facial expressions.
4.Basic and universal emotions.
5.Culture and emotions.
THE JAMES-LANGE THEORY, THE ATTRIBUTION-OF-AROUSAL THEORY
Some features of emotion, such as our gestures and expressions, are public and can readily be studied. Our physiological responses can also be studied using electronic monitors. But it is unknown how our emotions are experienced subjectively, the way we feel “inside”.
In nineteenth century psychologists tried to catalog various emotional experiences such as they had classified the different sensations provided by the senses . But their efforts were not very successful. Another approach to the problem was proposed by William James. To James, the crucial facet of emotion was that it is an aspect of what a person does. In fear we run; in grief we weep. The interpretation is that the behavior is caused by the emotion. James stood common sense on its head and maintained that the causal relation is reversed; we are afraid because we run.
This ideas are now known as the James-Lange theory of emotions. (Carl Lange was a European contemporary of James who offered a similar account). The theory asserts that the subjective experience of emotion is neither more nor less than the awareness of our own bodily changes in the presence of certain arousing stimuli. Such bodily changes might consist of skeletal movements (running) and visceral reactions (pounding heartbeat), although later adherents of the James-Lange theory emphasized the visceral responses and the activity of the autonomic nervous system that underlies them.
An alternative theory focuses on cognitive factors. Emotional experiences are usually initiated by external events - a letter with tragic news, a loved one’s return, a job failure. Events such as these bring grief, joy, dejection, or humiliation, but before they can possibly affect us emotionally they must be appraised and understood.
Stanley Schachter and Jerome Singer combine a cognitive approach with bodily feedback to explain emotion. According to Schachter and Singer’s attribution-of-arousal theory (sometimes called cognitive arousal theory) various stimuli may trigger a general state of autonomic arousal, but this arousal will provide only the raw materials for an emotional experience . This state of undifferentiated excitement is shaped into a specific emotional experience by cognitive appraisal and interpretation.
According to the attribution-of-arousal theory, emotional experience is produced not by autonomic arousal as such, but rather by the interpretation of this arousal in light of the total situation as the person understands it .
The role of the amygdala in emotional appraisal In there study Schachter and Singer had provoked considerable criticism and, like many claims about emotion, remains controversial . Their theory reminds us that our conception of emotion must include at least two elements - the bodily arousal itself and the cognitive appraisal of the circumstances attending that arousal. Some recent studies of the brain suggest that, while all levels of the brain from the hindbrain to the neocortex appear to be involved in emotion, a single structure - the amygdala - is largely responsible for integrating arousal with appraisal. The amygdala is well situated in the temporal lobe to perform this integrative role, receiving input from diverse areas of the brain, including sensory areas of the cortex and relay centers for sensory information in the thalamus .
Studies in 1937 conducted by Kluver H. and Bucy P.C. with humans and animals support the contention that the amygdala plays a central role in stimulus appraisal, tagging stimuli with their emotional or motivational significance. Thus, monkeys who had their amygdalas removed could recognize objects normally but could not distinguish what they were for: They would try to eat a block of wood or to touch a lighted match . Patients with damage to the amygdala do not acquire conditioned fear responses, even though they can (calmly) recall which visual or auditory stimuli were paired with the unconditioned stimulus .
In short all of these findings support the claim that the amygdala is essential in identifying the emotional significance of a stimulus with important consequences for our subsequent reactions to that stimulus.
Emotional Behavior: Facial Expressions.
Humans have a number of expressions associated with emotion, many of them conveyed by the face. Our expressions - our smiles, frowns, laughs, gapes, grimaces, snarls and winks - are intimately tied to our social lives, and these facial expressions have been of special concern to psychologists studying emotion.
Much of our current interest in facial expressions is due to Charles Darwin (Darwin, 1872 ), who hypothesized that humans possess a set of universal facial expressions that are vestiges of basic adaptive patterns shown by our evolutionary forerunners. For example, our “anger” face, often expressed by lowered brows, widened eyes, and open mouth with exposed teeth, reflects the facial movements our ancestors would have made when biting an opponent. Similarly, our “disgust” face, often manifested as a wrinkled nose and protruded lower lip and tongue, reflects how our ancestors rejected odors or spit out foods.
Darwin noted their similarities to many of the displays made by monkeys and apes, and believed that the expressions would be identical, reflecting identical emotions among humans worldwide even “those who have associated but little with Europeans” . To support this universality thesis, Darwin conducted one of the first cross-cultural studies, sending questionnaires to his colleagues in Europe as well as missionaries and other contacts in the Far East. In their answers to his questions Darwin’s respondents provided many cases that suggested the universality of facial expressions. But Darwin’s evidence was not authentic, and only in the 1960s did psychologists begin to test the universality thesis across cultures using more rigorous experimental methods.
In one of these authentic studies, American actors posed in photographs designed to convey emotions such as happiness, sadness, anger, and fear. The pictures were then shown to members of different cultures, both literate (Swedes, Japanese, Kenyans) and nonliterate (members of an isolated New Guinea tribe barely advanced beyond Stone Age culture), and they were asked to pick the matching emotion label. In other cases the procedure was reversed. For example, the New Guinea tribesmen were asked to portray the facial expressions appropriate to various prototypical situations such as happiness at the return of a friend, grief at the death of a child, and anger at the start of a fight . Photographs of their performances were then shown to American college students who were asked to judge which situation the tribesmen had been asked to convey (Ekman and Friesen, 1968) .
When given photographs of facial expressions and asked to supply the appropriate emotion term, participants worldwide - even those in relatively isolated cultures - do reasonably well . The same is true if participants are asked to describe an emotionally tinged situation that might have elicited the expression shown in the photo. But their success depends in part on the particular facial expression they are shown. Smiles - which are generally matched with “happy” terms and situations - produce much greater consistency in identification than all the other expressions .
CULTURAL VARIATIONS IN FACIAL EXPRESSIONS
It is clear that the public use of facial expressions is affected by culture. For example: Melanese chieftains frown fiercely when greeting each other at a festive occasion, and Samurai mothers are said to have smiled upon hearing that their sons had fallen in battle .
Emotion differences may reflect cultural display rule. So far we have treated facial expressions as though they were the natural and spontaneous outcome of an underlying emotional state. That is not to say that we can’t hide or fake an emotional reaction, but, in general, when we are happy we smile; when sad we cry. Some researchers contend that our facial expressions are primarily communicative displays that are not so much a revelation of an inner state as they are a message to others about actions we may take or wish others to take.
Basic and Universal emotions.
Many theorists sopose that several basic emotions underlie the wide range of emotions that humans are able to experience and that the complex emotions we feel are composites of the basic emotions. Others question the existence of basic emotions pointing to the fact that lists of so-called basic emotions vary from researcher to researcher and that supporters don’t agree on what makes an emotion “basic”. Complex emotions are those that require a high level of symbolic processing. Some depend on the judgments that a bad outcome was controllable (anger) or that it was not (pity). Others depend on the construction of cognitive scenarios that involve what might have been (regret).Still others depend on an “ as if “ experience, such as the emotions we feel while watching a theatrical performance
Basic emotions are generally assumed to be closely tied to our biology - rooted in our evolutionary past and shaped by hard-wired patterns in our nervous system. If so, then basic emotions are a trait of our species and should be found in all cultures. It is notable that the common lists of “basic” emotions used in cross-cultural research were all constructed by Westerners, because, in fact, cultures differ widely in their emotion lexicons - the vocabularies available to describe emotions. Obviously, the words used by different peoples to denote emotions may tell us little about their inner, emotional lives. But if certain emotions are truly basic and universal, then one might expect all cultures to share roughly the same categorization of emotions. Across cultures one finds no common list of basic emotions. Some cultures appear to have no words for emotions that many Westerners consider basic; thus, the people who live on the western Pacific Island of Ifaluk lack a word for surprise, and the Tahitians lack a word for sadness. Other cultures have words that describe common emotions for which we have no special terms. Thus, the Ifaluk often feel an emotion they call fago, which involves a complex mixture of compassion, love and sadness experienced in relationships in which one person is dependent on the other. And the Japanese report a common emotion called amae, which is a desire to be dependent and cared for . The German language reserves the word Schaden-freude for the special pleasure derived from another’s misfortune.
Questions and tasks on main topics .
1 What is the difference between the James-Lange and Sachachter-Singer theories of emotions?
2 What is the amygdale’s role in emotional appraisal?
3 How did Ch Darwin explain the emotional processes in human?
4.What is the difference between basic emotions and complex emotions?
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