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Published byGertrude Russell Modified over 8 years ago
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Sensation and Perception Sense – a system that translates outside information into activity in activity in the nervous system Sensation – messages from senses; shape behavior & mental processes between self & environment. Perception – using sensations & understandings of environment to create meaningful experiences. Accessory Structure – 1 st step in sensation is to modify the incoming stimulus, use of some part of senses. (Outer ear, lens, taste buds) Transduction – 2 nd step in sensation is to convert incoming energy into neural activity Receptors – place where transduction occurs, detect certain forms of energy. Adaptation – a constant level of stimulation decreases responsiveness to the stimulus. Coding – translates environment into a pattern of neural activity that tells us what things are.
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I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt!
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Count every " F" in the following text: FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS...
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Measuring Senses Absolute threshold – smallest amount of energy a person can detect reliably, 50%, of the time. Internal Noise – random firing of cells in the nervous system, can be mistaken for something in environment. Response Criterion – person’s willingness to respond to stimulus Difference Threshold (JND – just-noticeable difference) – smallest difference in stimulation a person can detect reliably, 50% of the time. Signal Detection Theory – a person’s response to energy or signal is split into a sensory process and a decision process. Sensory Deprivation - a lack of normal levels of sensory stimulation. Little is ok, extended periods makes people very confused, grouchy, disoriented, restless. Selective Attention – protects people from becoming overwhelmed by signals or energy.
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How We See Stimulus for vision is LIGHT We see the world based on the characteristics of light wavelengths: Wavelength – distance between peaks of one wave to another. Frequency - # of wave cycles that pass a set point in a set amount of time. Amplitude – height of wave from baseline to peak. 1. Hue – color – based in part by the wavelength of the light. 2. Brightness – the amount or intensity of the light. 3. Saturation – colorfulness of the light. A single wavelength is said to be PURE or completely saturated.
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How We See
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Visual System Cornea – out layer to the eye Lens - the light gets focused Retina –image is sent to the brain. Photoreceptors - Rods – more sensitive to light Cones – less sensitive to light Dark Adaptation – 10k x’s more sensitive to light after ½ hr. in dark. Ganglion Cells – neurons that form the optic nerve In vision, brain takes fragments of information & fills in rest to make a continuous picture.
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Hearing Hearing- auditory link to our environment. Loss of hearing causes some to feel socially isolated. Many deaf people learn American Sign Language.
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Sound is measured by: Loudness: is due to the intensity or maximum height of a sound wave and is measured in decibels. Pitch: is due to the frequency of the sound wave or how fast the air vibrates. Timbre: is the distinguishing quality of a sound. This is what makes the same note played on different instruments sound different even though it is the same note. White Noise – is when all the frequencies (apprx. 20,000) of the sound spectrum occur at the same time. A hissing sound is produced. It is used to drown out unwanted noise.
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3 Parts of the Ear Outer Ear, Middle Ear and Inner Ear How you hear – 1.Sound enters the ear. 2.Sound vibrates the eardrum 3.Eardrum vibrates the tiny bones which intensify the vibrations. 4.Those vibrations then hit the cilia or tiny hair like receptors and cause the cilia to vibrate. Vibrating the cilia causes a signal to then be sent to the brain via the auditory nerve
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Hellen Keller Anne Sullivan
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Taste, Smell, & Senses of the Skin Taste - due to chemicals stimulating receptors in the mouth. Receptors are located on the tongue and the throat. Taste buds line the sides of each papillae or tiny bumps on the tongue. No taste buds are located on the center of the tongue. Four basic tastes: Salty, Sour, Bitter, Sweet Sweet tastes are universal but the other tastes seem to be learned. Genetic differences make people more or less sensitive to chemicals. “Supertasters” have more taste buds then “non-tasters” Smell – odor molecules bind to mucous membrane & activate receptors Pheromones – chemicals released by animals, when another animal detects it, it can shape the other animals behavior or physiology. Not strong in humans.
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Visual Cliff test – Babies younger then 6 months can sense a difference between shallow and deep. 6 months and older have a lot of experiences to this point so most react to the visual cliff. All senses are either inborn or develop early on in life not just sight. Psychological factors can influence how we perceive the world: 1.Needs – more likely to perceive something if we want it or desire it. 2.Beliefs – what we believe to be real or not can determine whether we perceive something or not. 3.Emotions – emotional responses can a great impact on what we perceive or not. 4.Expectations – previous experiences often influence the way we perceive our environment. Origins & Influences of Perception
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Ebbinghaus Illusion (Moon Illusion)
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Gestalt’s Laws of Grouping Continuity Closure Proximity Similarity Pragnanz Connectedness
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Figure-Ground Relationship
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Wundt-Hering Illusion Zollner Illusion
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Ponzo Illusion
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Extrasensory Perception (ESP) Those who say they can communicate without using the normal sensory channels are said to be using extrasensory perception or ESP or Psi ( psychic phenomena) There are 4 types of ESP: 1.Telepathy – direct communication between two minds without the usual visual, auditory or any other sensory communication. 2.Clairvoyance – is the perception of an event or fact without normal sensory input. 3. Precognition – is the perception of an event before it has happened. 4. Out-of-body Experiences – perception of one’s own body from “outside” of the body, as an observer might see.
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Parapsychologists are people who study and try to prove or disprove the existence of ESP There is no credible evidence that says ESP exists beyond the odds of chance or 25% of the time. Lesson from the Magician – you cannot always trust what you see or what you think you see. Your eyes are not always the best evidence to find out the truth.
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