Free Essay

Constancies and Illusions

In: Philosophy and Psychology

Submitted By Kate0801
Words 879
Pages 4
Constancies and Illusions
What are Perceptual Constancies? * Tendency for the perception of an object to stay constant despite changes in stimuli * Perceptual constancies rescue us from confusion * They allow us to identify objects with different stimuli
Three types of constancies: * Size * Shape * Brightness

Size Constancy * The most studied of all constancies is size constancy, the fact that an object’s size remains relatively constant no matter what its distance. As an object moves farther away from us, we generally do not see it as decreasing in size. Hold a quarter a foot in front of you and then move it out to arm’s length. Does it appear to get smaller? Not noticeably so. Yet the retinal image of the quarter when it is 24 inches away is half the size of the retinal image of the quarter when it is 12 inches away. We certainly do not perceive the quarter as becoming half its size as we move it an arm’s length. Like other constancies, however, size constancy is not perfect; very distant objects appear to be smaller than the same objects close up, as anyone knows who has looked down from a tall building or from an airplane in flight.

Shape Constancy * Tendency for the perceived shape of an object to remain constant despite changes in its retinal image.
Ex. A book will have the same shape regardless of the angle it is viewed from.

Brightness Constancy * Tendency for the perceived brightness of an object to stay the same as long as it is illuminated by the same amount of light. * Object and background must have same lighting
Ex. A book on a lighted desk is the same as the one in a dark room.

Illusion

a misrepresentation of a “real” sensory stimulus that is, an interpretation that contradicts objective “reality” as defined by general agreement. For example, a child who perceives tree branches at night as if they are goblins may be said to be having an illusion. An illusion is distinguished from a hallucination, an experience that seems to originate without an external source of stimulation. Neither experience is necessarily a sign of psychiatric disturbance, and both are regularly and consistently reported by virtually everyone.

The nature of illusions

Illusions are special perceptual experiences in which information arising from “real” external stimuli leads to an incorrect perception, or false impression, of the object or event from which the stimulation comes.
Some of these false impressions may arise from factors beyond an individual’s control (such as the characteristic behaviour of light waves that makes a pencil in a glass of water seem bent), from inadequate information (as under conditions of poor illumination), or from the functional and structural characteristics of the sensory apparatus (e.g., distortions in the shape of the lens in the eye). Such visual illusions are experienced by every sighted person.

Another group of illusions results from misinterpretations one makes of seemingly adequate sensory cues. In such illusions, sensory impressions seem to contradict the “facts of reality” or fail to report their “true” character. (For more-profound philosophical considerations, see epistemology.) In these instances the perceiver seems to be making an error in processing sensory information. The error appears to arise within the central nervous system (brain and spinal cord); this may result from competing sensory information, psychologically meaningful distorting influences, or previous expectations (mental set). Drivers who see their own headlights reflected in the window of a store, for example, may experience the illusion that another vehicle is coming toward them even though they know there is no road there.

3 Types of illusion

Optical Illusions An optical or visual illusion is a kind of illusion in which the images perceived through the sense of sight tend to be misleading or deceptive, causing errors in perception. An optical illusion is based on the process through which the brain creates a visual world in one's mind using either or both these two sources: previous memory stored in it and the current presentation of the object in the environment. In order for perception to occur, the brain tries to organize sensory information related to the object as gathered by the eye. This leads to the formation of a percept. If there are any gaps once the percept is created, the brain attempts to fill in such gaps. However, the percept may not represent or interpret the real, physical measurement of the stimulus. Thus, an optical illusion emerges.
Auditory Illusions
While optical illusions deceive the eyes through visual images, auditory illusions mislead the ears through sounds. These sounds are usually those that are not really present in the physical stimulus, but is heard by the ears and perceived as a sound related to the stimulus in the environment. There are also auditory illusions that come from "impossible sounds", such as hearing a missing fundamental frequency, provided that there are other portions of the harmonic series, and different psychoacoustic tricks of lossy audio compression.
Tactile Illusion
While optical and auditory illusions are common manifestations of several psychological disorders such as schizophrenia and psychosis, tactile illusion is experienced by patients who have undergone amputation. The phantom limb is a tactile illusion wherein the patient still 'feels' pain on the leg, arm, or digit that has already been removed.

Similar Documents

Free Essay

Ask for Help

...Midterm Reviewer General Psychology Psychology – is the scientific study of behavior and mental processes. Wilehelm Wundt – “Father of psychology” * Aristotle – methods of Contemporary Science. * Francis Bacon – Deductive Reasoning in the study of behavior. * Charles Darwin – 1859, Theory of Evolution. * Psyche – mind / soul * Locos – study 4 Goals of Psychology * Describe – Detailed of record of ascertain behaviour. Qualitative – names, sex, and nationality, rating/ranking. Quantitative – weights; height, speed, distance, no. of age. * Understand - explain or interpret facts about behavior. The causes of certain. Sign learning. Verbal punishment. Dispositional – nature of personality/ reason. * Predict – predict future behavior. a) Scientific b) Casual c) Cause and Effect * Control – controlling behavior may be done thought planning based on accurate prediction. Traditional Schools of Psychology * Structuralism – structure of the mind. (Edward B. Titchener) a) Sensation b) Image c) Feelings Introspection – a method of metal self-analysis w/c feeling, thinking, & behavior. * Functionalism – how the mind function in the adjustment of man to his environment. ( William James) [ Experimental ] * Functional * Advises * Gestalt – the whole is greater than the sum of its parts. ( Max Weltheirmer, Wolfgang Kholer, & Kurt Koffka ) [ Experimental ] * Behaviorism – The important of learning......

Words: 1589 - Pages: 7

Free Essay

Psych Illusion

...The first illusion was the Muller-Lyer Illusion. It consists of an arrow shape in which the arrowhead faces different directions. In the middle of the shape is another arrowhead that is supposed to divide the length of the arrow in half. The left-facing arrow illusion did little to affect my perception of the distance. However, I was consistently short on the right-facing arrow. The alignment of the arrow drastically affected my perception. I thought I was consistently dividing it in half, but the results showed otherwise. My average adjusted length was about 5.25% less than the correct length. The Muller-Lyer illusion works by altering our depth perception. Because most of us were brought up in square-cornered houses, the >-< shape appears closer and shorter than the shape. This is because the former looks like the edge of an exterior corner and the latter looks like the edge of an interior corner. This causes our mind to perceive the first shape as shorter than the second one, even though they are the same length. After learning about this phenomenon, my score improved from 5.25% to 3.25%. I still haven’t clearly grasped the concept and been able to perceive it correctly, but I did make a slight improvement. The Ponzo Illusion consists of a red and yellow bar whose heights must be matched. The two bars are placed in a room with the red bar much further back than the yellow bar. My perception was significantly affected by this illusion as I made the yellow bar about 49.5%...

Words: 677 - Pages: 3

Free Essay

Psychology

...STUDIES OF THE DEVELOPMENT OF PERCEPTUAL ABILITIES Are we born with ability (nature, bottom up, nativist) or is it acquired through experience (nurture, top down, empiricist). Can look at infants abilities and /or people living in different environments to try and answer this. GENERAL AO2 limitations Infant studies. (Neonate) Abilities not present at birth not necessarily learned – may require later development. Some may actually get experience in the womb i.e. not innate even if present at birth. Assessment very difficult – e.g. motor skills and acuity – acuity 10-30 times poorer than for adult therefore difficult to assess e.g. depth perception Techniques may not be reliable- may respond to inadvertant cues from experimenter – experimenter bias (cannot ask them) Methods used • Habituation • Sucking rate • Preferential looking • Conditioning • Heart and breathing rate • PET scans Infant studies AO1 Gibson and walk visual cliff – used infants 6 – 14 months old –most refused to cross onto deep side even when enticed by parents – suggests innate ability AO2 Infants 6+months so could have learnt –when done on new born mobile animals – they wouldn’t cross – but animals not humans. Compos – babies placed on both sides heart rate measured. On deep side decreased in very young suggesting they could perceive depth i.e. an innate ability, but not worried, older infants heart rate increased suggests not only perceive depth but......

Words: 1840 - Pages: 8

Free Essay

Sensation and Perception

...Chapter 4: Sensation and Perception Lecture 6 & 7 • Learning Outcomes • Define and differentiate between sensation and perception. • Identify the parts of the eye, describe the properties of light and the theories of color vision. • Learning Outcomes • Describe how visual perception is organized. • Identify the parts of the ear; explain the sense of hearing. • Learning Outcomes • Describe the chemical senses. • Identify the skin senses and theoretical explanations for pain. • Learning Outcomes • Describe the kinesthetic and vestibular senses. • Explain why psychologists are skeptical about extra sensory perception. • Sensation and Perception • What are Sensation and Perception? • “I have perfect vision” –Heather Sellers has problem with her perception. She cannot recognize faces-prosopagnosia (face blindness) “In college, on a date at the Spaghetti Station, I returned from the bathroom and plunked myself down in the wrong booth, facing the wrong man. I remained unaware he was not my date even as my date (a stranger to me) accosted Wrong Booth Guy, and then stormed out of the Station. I can’t distinguish actors in movies and on TV. I do not recognize myself in photos or video. I can’t recognize my stepsons in the soccer pick-up line; I failed to determine which husband was mine at a party, in the mall, at the market” This curious mix of “perfect” vision and face blindness illustrates the distinction between sensation and perception. • 1. What are......

Words: 1809 - Pages: 8

Premium Essay

Document

...Chapter 4: Gender and Sexuality * What is sex? What is gender? How do they differ? * Summarize the main physical differences between females and males (not genitalia), such as life expectancy * Summarize the main psychological differences between females and males (such as aggression, social power, and social connections) * How do chromosomes determine sex? What role does the Y chromosome play? * What is intersexuality? What causes it? * What is gender identity? * Define transgender * What are gender roles? How do they develop? * Social learning theory * Gender schema theory * How do hormones influence our sexuality? * What are the four stages of the human sexual response cycle? * What are STIs, and how can they be prevented? * What factors influence adolescents' sexual activity and contraceptive use? * Discuss the roles of external and internal stimuli in sexual arousal * What is sexual orientation? * How do nature and nurture work together to create sexual orientation? * What is evolutionary psychology, and how does it explain human sexuality and gender roles? * Summarize the arguments against evolutionary psychology's explanations Chapter 5: Sensation and Perception * What is sensation? What is perception? How do they differ? * What is the process of transduction? * What is psychophysics? * What are absolute thresholds and......

Words: 605 - Pages: 3

Free Essay

Life Span Development and Personality Paper

...Sensation and Perception Chapter: Sensation and Perception Sensation and Perception Sensation versus Perception Psychophysics and Thresholds Vision USING PSYCHOLOGY: Color Visual receptor: The Eye Operation of the Eye Eye Problem: Color Blindness Hearing Operation of the Ear Ear Problem: Deafness Chemical senses—Smell and Taste Chemical Senses Receptors: The Nose and Taste Buds Operation of the Chemical Senses Other senses: Skin Other Senses: Balance and Body Position Perception Figure-ground Perception The Wholeness of Figure Perception Perceptual Grouping Perception and Attention Stimulus Variation and Perception Perceptual Constancies Visual Perception of Distance Visual Perception of Motion Hearing Perception Illusions as "Errors" in Perception USING PSYCHOLOGY: Clothing Extrasensory perception (ESP) REVIEW QUESTIONS ACTIVITIES INTERESTED IN MORE? 183 Sensation and Perception WHAT'S THE ANSWER? Instructors in Driver Education advise their students to look twice in both directions before driving across an intersection. Why? "Watch it, Klausman! Watch where you're going!. . . Well, would you look at that. He ran into the goal post!" PSYCHOLOGY: Exploring Behavior Sensation and Perception 184 Moments later, "Klausman, how many times have I told you? You've got to look where you're going! What if that had been a defensive player from the opposing team? How do you feel?" "I feel OK, coach, but I've got a bad ringing in my ears." What causes the ringing......

Words: 13801 - Pages: 56

Free Essay

Psychology

...SENSATION AND PERCEPTION REVIEW OF RELATED LITERATURE (FOREIGN) I. PSYCHOLOGY (Douglas A. Bernstein, Edward J. Roy, Thomas K. Skull, Christopher D. Wickens) BIOLOGICAL ASPECTS OF PSYCHOLOGY CONSCIOUSNESS MOTIVATION EMOTION PERCEPTION SENSATION The diagram above illustrates some of the relationships between different aspects of psychology through sensation. What happens if people are denied on this contact, if they deprived of stimulation form the senses? However, recent research has made it more difficult to draw a clear line between sensation and perception. That research shows that the process of interpreting sensations begins in the sense organs themselves and continues into the brain. Even previous experience can shape what you sense, causing you not to notice. Sensory Systems The senses gather information about the world by detecting various forms of energy, such as sound, light, heat, and physical pressure. For example, the eyes detect light energy, the ears detect the of sound , and the skin detects the energy of heat and pressure. Humans depend primarily on vision, hearing, and the skin senses to gain information about the world: they depend less than other animals on smell and taste. There are also senses that provide information to the brain from the rest of the body. All of these senses must detect stimuli, encode them into neural activity, and transfer this coded information to the brain. Steps in Sensation At each......

Words: 4634 - Pages: 19

Free Essay

Arundel : Options Case

...a great example of the Realist movement in art. Manet’s original title for the painting was “Jesus Insulted by the Soldiers.” Clearly, Manet did not mean to represent the soldiers' behavior in the way that title implied. Recently, once again, its name was changed to “Jesus Mocked by Soldiers.” Some sources also refer to it as “Christ Scourged.” In the center, Christ, the brightest figure, is sitting in a chair surrounded by three other male figures, soldiers. This scene is also known as the mocking of the “king of the Jews” before the execution. In this painting, the author creates an illusion of three-dimensional space by using atmospheric perspective. Even though there is no background to create a believable space by comparing sizes of elements that are upfront to those that are farther away, the figures of Christ and the soldiers do look very natural. The illusion of depth was achieved by the chiaroscuro technique: the contrast between light and dark....

Words: 1280 - Pages: 6

Premium Essay

English Analysis

...and save the younger generation and ourselves. Getting rid of technology is not the answer, but knowing our limits and remaining focus on a single task can allow us to stay a bit more humanized. Many of us have heard of social networking sites such as, Facebook, Twitter, or Instagram. These sites are great means of expressing yourself or to portray a type of image, but there is point where people online cross the line. Constantly putting personal business out there for others to know can create hostile environment and even an unsafe one. People create an illusion, where constantly checking our social networks for notifications that are not there, and people statuses in which I have already scrolled by twice already. In the article Is Facebook Making Us Lonely, Stephen Marche says, “What’s truly staggering about Facebook usage is not it’s volume – 750 million photographs uploaded over a single weekend - but the constancy of the performance it demands. More than half it’s users – and one of every thirteen people on Earth is a Facebook user – log on everyday. Among...

Words: 1019 - Pages: 5

Free Essay

Cosi

...Personal Transformation * LEWIS (TECHNIQUE: Dialogue, stage direction, relationship with other characters?) 1. The character of Lewis significantly grows in the play. 2. At the beginning of the play, Lewis lacks any direction or creative vision and merely just participates as he ‘needs the money.’ At this point, Lewis is still influenced by the ideals of his roommates Lucy and Nick, thus suggests that “Love is not so important nowadays.” 3. “They’re mad. Its madness...” Shows ignorant view of mental patients. The use of dialogue in the play conveys Lewis progression and personal transformation. 4. A sign of his progression is seen in his development of relationships with the patients, i.e. Julie? Kissing her passionately and stuff. 5. Dialogue creates tension during Lewis’ altercation with Lucy where she forces him to choose between Cosi or Moratorium committee, Lewis chooses Cosi, “Mozart. I’m not going to let them down.” “Its about important things - like love and fidelity.” Major moments in the play that regard Lewis : “That’s why she spends so much time in the toilets... Its where she smokes.” “From today, I’m also in the play.” Lewis playing Ferrando as Doug’s replacement Persuading Henry to stay, building trust in Henry... They’re on common grounds, “I’m not letting you walk out on us. You’ll have to hit me to get out.” Encouraging Roy to maintain his role in the play, “I can’t remember my lines. Not one. Gone.” * HENRY Henry also......

Words: 3002 - Pages: 13

Free Essay

Cognitive Science

...those 2 cones/ if miss L, then can’t tell red from green Blue/yellow: (s-s+m/2) Explicit: conscious Episodic/semantic Implicit: skill memory LTP: stronger synaptic connection Long term: grow more receptors on post synapse anatomical Short term: amount of neurons Turing machine Single vs double dissociation Single: one manipulation Double: two manipulations Visual angle Grandmother cell a lot of cells respond for Halle Berry Do not respond only to Halle Berry Math: impossibly large number of neurons Only 100 images do not necessarily show that those cells only respond to one concept Size constancy: If no depth cue/ with out size constancy; then same visual angle same proximal size and same perceived size. s Alternative: different difficulties of those 2 tasks Mediate by separate part of brain regions Color constancy Binding: different percepts What is intelligence? (Cartesian) Dualism, identity theory, functionalism The Turing test (and objections to it) Aunt Bertha machine Linear vs. exponential scaling Dualism: mind is nonphysical substance Identity theory: same mind state means the same brain state Problem of strict...

Words: 4004 - Pages: 17

Free Essay

A Closer Look at the Work of Dh Lawrence

...A Closer Look At The Work Of DH Lawrence Throughout the work of DH Lawrence there is the common theme of the relationships between men and women. In these three stories we explore the uncertainties of romantic love. All of the characters discover that they have not seen the other as they truly are but rather as an idealized and impossible halucination. In Elizabeth's case in Odour of Chrysanthemums she realizes the truth of her relationship with her husband Walt when she is faced with his death. The cold room magnifies the feeling of their distance, and when she compares Walt's mothers response to her own she knows she has not loved him or ever really seen him. Hilda reveals to Syson that he never could accept her how she truly is, that he could never love her if he really saw her, and this is why she broke things off with him. Hilda shows off the antique chair she has found, and Syson is suprised that she would like something like this. He begins to notice Hilda may not be the person he thinks he knows. She shows him the scissors that she found hidden in the chair, and has him try them on. She is pleased with herself when Syson's fingers fit into the scissors perfectly, and claims that she suspected they would. She is telling him that he needs to cut off this attatchment to her. In Shades Of Spring his wife's past is unveiled before him revealing the reason for her distance and coldness towards him, and also a women he did not see before. He feels she......

Words: 1749 - Pages: 7

Premium Essay

General Psychology

...Chapter 1 The Dimensions of Psychology Summary: Psychology is an academic and applied discipline that involves the scientific study of mental functions and behaviors. Psychology has the immediate goal of understanding individuals and groups by both establishing general principles and researching specific cases, and by many accounts it ultimately aims to benefit society. In this field, a professional practitioner or researcher is called a psychologist, and can be classified as a social, behavioral, or cognitive scientist. Psychologists attempt to understand the role of mental functions in individual and social behavior, while also exploring the physiological and neurobiological processes that underlie certain cognitive functions and behaviors. Structuralism was the first school of psychology and focused on breaking down mental processes into the most basic components. Researchers tried to understand the basic elements of consciousness using a method known as introspection. Wilhelm Wundt, founder of the first psychology lab, was an advocate of this position and is often considered the founder of structuralism, despite the fact that it was his student, Edward B. Titchener who first coined the term to describe this school of thought. Functionalism formed as a reaction to the structuralism and was heavily influenced by the work of William James and the evolutionary theory of Charles Darwin. Functionalists sought to explain the mental processes in a more systematic and......

Words: 20821 - Pages: 84

Premium Essay

Apostolate

...Apostolate Talk – Retreat 25 March 2016 Good Friday “Hidden wisdom and unseen treasure, what advantage is there in either of them?” Apostolate is really sharing, an overflow of our own interior life. As I was preparing for this talk, I was going over my old notes. It’s good to write down what inspires especially in spiritual activities such as this one, and go back to from time to time to draw lessons. I came across the following passages in my notes to answer the question on “how do you re-Christianize Society?” or how do you do Apostolate? I do not own these lines nor do I remember where I got it from but these are as relevant as it is now. To quote, “Since doctrinal subjects have to be repeated, we should make a special effort to present them attractively, so that people don’t get bored with hearing them again and again. We say the same things, but in different ways. Faith and morals obviously remain the same, but our style can be fresh and varied. The same ideas but in a hundred different languages, pleasantly, so that our speech may always be gracious, seasoned with salt, so that you may know how you ought to answer everyone. Addressing people “in their own language” is certainly a start, but in doctrinal apostolate we also need to say the same things over and over again, firstly because what we say may not be properly grasped in a single hearing, and secondly because it may not be retained. Fearless repetition is the norm. One has to go back over things.......

Words: 3274 - Pages: 14

Free Essay

Adkkk

...Psychology is an academic and applied discipline that involves the scientific study of mental functions and behaviors.[1][2] Psychology has the immediate goal of understanding individuals and groups by both establishing general principles and researching specific cases,[3][4] and by many accounts it ultimately aims to benefit society.[5][6] In this field, a professional practitioner or researcher is called a psychologist and can be classified as a social, behavioral, or cognitive scientist. Psychologists attempt to understand the role of mental functions in individual and social behavior, while also exploring the physiological and biological processes that underlie cognitive functions and behaviors. Behavior Behavior or behaviour is the range of actions and mannerisms made by organisms, systems, or artificial entities in conjunction with themselves or their environment, which includes the other systems or organisms around as well as the (inanimate) physical environment. It is the response of the system or organism to various stimuli or inputs, whether internal or external, conscious or subconscious, overt or covert, and voluntary or involuntary. Branches of phychology 1. Abnormal Psychology  Abnormal psychology is the branch of psychology that looks at psychopathology and abnormal behavior. The term covers a broad range of disorders, from depression to obsession-compulsion to sexual deviation and many more. Counselors, clinical psychologists, and psychotherapists......

Words: 1839 - Pages: 8