Chapter 3- Sensation and Perception
Chapter 3- Sensation and Perception PSY0010
Popular in Introduction to Psychology
verified elite notetaker
Popular in Psychlogy
This 15 page Class Notes was uploaded by Brittany Blades on Friday March 20, 2015. The Class Notes belongs to PSY0010 at University of Pittsburgh taught by Dr. Lausberg in Fall. Since its upload, it has received 80 views. For similar materials see Introduction to Psychology in Psychlogy at University of Pittsburgh.
Reviews for Chapter 3- Sensation and Perception
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 03/20/15
Introduction to Psychology Chapter 3 Notes Sensation and Perception What is sensation Sensann o Occurs when special receptors in the sense organs are activated Transduction 0 Process of converting outside stimuli into neural activity such as a light a sound Sensory Thresholds Difference thresholds 0 Also known as quotjust noticeable differences or quotjndquot o The smallest difference between two stimuli that is detectable 50 of the time Whatever the difference is it is always a constant Absolute threshold 0 Lowest level of stimulation that a person can consciously detect 50 of the time the stimulation is present Examples of Absolute Thresholds SENSE THRESHOLD Si ht Candle ame at 30 miles away on a 9 clear dark night Tick of a watch 20 feet away in a quiet Hearing room Smell One drop of perfume diffused throughout a 3 room apartment Taste 1 teaspoon of sugar In 2 gallons of water Touch Bee s wing falling on the cheek from one centimeter above Habituation and Sensory Adaptation Hab ua on o The way the brain deals with unchanging information from the environment Example You quothearquot the noise but don t pay any attention to it Sensory adaptation o Unchanging information from sensory receptors is ignored l l 7 l7 T J L 7 7 7 IL 7 777 m a 7 llwauclla l ll ll 7M H M vii l l 1 ll lT T T T WT T T 7 l H M w H 7l 7l 7 7l l TWWT T WT TWrr 7 H H w ll 7 7 77 7 7777 77 7 li lw ll li 7 l7 7 l7l7 l7 7 l l l 7 7H7 7 7 7 7l7 7 7 7l ll ll 7 7 7 y7 7 7 7 l w 7 T 7 7r 7 7W7 7 7 7 7 T 1 H T 7 I 7 T WT T T T T T WT Tr T W Tl 77 T WT T w l lil ll l ll ll ll ll ll llil il ll l l l l 77739l7 77 7 7 777quot 7 77739l7 T7 1 T WT Tr T Tr WT TT ll l M l 7 l W V 7 7 7 7quot T 7quot 7 7 lt7 lT lT lEl ll ET 7 l llvil 4L 7 lEl ll i D T WTll39T WT ll 7 7 l7 7 7 7 The Science of Seeing Perceptual Properties of Light Photons 0 Have speci c wavelengths associated with each photons Three aspects to our perception of light 1 Brightness gt Determined by amplitude how high or low the wave is of the wave gt Long wavelengths are on the red end of the visible spectrum gt Short wavelengths are on the blue end of the visible spectrum 2 Saturation n1 I LL AI I I A Visible Spectrum Re lle Miereweves Infrared 391 Ullmraviellet iiian Gamma Ra AllIling lFrrequelnley Ehert Wavelength Lew Frequency Leng Wavelengthquot 39 The Structure of the Eye From Front to Back Parts of the Eye Light enters the eye directly light sun or indirectly re ection off an object o Refraction Light bending as it passes through substances of different densities a Cornea clear membrane covering the eye surface oz Protects the eye Focuses most of the light coming into the eye Has a xed curvature like a camera that doesn t have an option to change focus v Change curvature with sightimprovement techniques 9 Photoreactive keratectomy PRK O Laserassisted in situ keratomileusis LASIK b Aqueous humor clear watery uid oz Replenishes and supplies nourishment to the eye c Pupil hole of the eye 3 Light enters the interior of the eye d lris round muscle colored part of the eye 3 Changes the size of the pupil to let in more or less light l helps focus image e Lens behind the iris suspended by muscles clear structure oz Finishes the focusing started by the cornea 0 Process known as quotvisual accommodationquot 0 Changes shape from thick to thin depending on distance on the object O Presbyopia disorder where the lens hardens due to aging O Myopia also known as nearsightedness shape of the eye causes focal point to fall short of the retina O Hyperopia also known as farsightedness focus point behind the retina f Vitreous humor clear jellylike uid oz Nourishes the eye oz Gives the eye its shape g Retina lightsensitive are at the back of the eye containing 3 layers 1 Ganglion cells 0 Axon forms the optic nerve 2 Bipolar cells 0 Type of interneuron 0 Have single dendrite on one end single axon on the other end 3 Rods and cones o Receives light photons turns them into signals for the brain 9 O 90 90 O Cornea Aqueous upiISlris Lens ous Retina Rodsamp olar glion 1umor lor cones lls 5 LOCATED IN THE RETINA o Involved in ne detail 0 Most concentrated at the center of the retina where there are no rods an area known as the fovea o Responsible for color vision stimulated by different wavelengths 0 Found everywhere in the retina EXCEPT in the fovea o Concentrated in the periphery o Sensitive to change in brightness o Responsible for peripheral vision 0 The blindspot the area in the retina where the axons of the three layers of retinal cells exit the eye to form the optic nerve insensitive to light Haj napw Iril s awning 39h j l 39g an adagenah m the amount IIquotl r in the entrainment 1 l l39lt39sw imi fl Emitrul 1333 at the piJEaiil P I ft g liquid that r new iiie V VHF quot lL 5 ins ChangI15 shapn Tn taTing atria13 LthIIE fouls n Rustinn Eli39li nliEIHTE galIm rmepil i39 tells f i 7 iinn39ii rsl H13 rst 39 F iihe ElwinElli 39l Eilmll r In llEm n pm mm Mi 7 542ml annual 39 Er i in r mat l r in Iliai3 brain ilngh l magEl f sail We all image gram EiiE39 trussEn on like 39I E u iriw u 7 L F11 i L Illlind EFE IQIFili disc L Wham 13hr lirg newI Elma H F39 leajh39aa nhe seare than are m liona amptepi ir ILEIEEL were 39ll hailrim L Hell uke laqumlthai r miniurau39IHans gasE5 magicL it 1t2i thniwu How the Eye Works light entering can be separated into left and right visual elds 0 Light from the right falls on the left side of each eye s retina 0 Light from the left falls on the right side of each eye s retina Light travels in a straight line through the cornea and lens 0 Causes the image to be projected upside down and reversed from left to right on the retina Areas of the retina divided into halves Information from the right visual eld goes to the left visual cortex and vice versa because the axons cross over to the visual cortex on the opposite side of the brain LE1 virtual lintlid Flight visual field Left eye 7 Hi era Point of crossover Heme signal Left lull l ll l Hiigll39iit visual cortex tone Dark adaptation o Occurs as the eye recovers its ability to see when going from a bright lit state to a dark state 0 Rods allow eyes to adapt to low light 0 Process takes longer as aging increases Light adaptation o Occurs when going from a darkened room to one that is brightly lit 0 Cones adapt to increased light Adapt faster than rods do to darkness Perception of Color Trichromatic quotthree colorsquot theory 0 First proposed by Thomas Young in 1802 modi ed by Hermann von Helmholtz in 1852 0 Proposed three types of cones 1 Red cones 2 Blue cones 3 Green cones Three primary colors of 0 Different shades fcc light ints of light received by each of ti Cones re their l ers 0 Paul K Brown and Ge types of cones each sensitive to a r BlueViolet sho 39 Green mEdium quotU39V39vnuwl vvvvw WV Depending on intensity Greenyellow long wavelength about6 of the ght either cones OpponentProcess theory can respond to light that 0 Proposed by Edward Hering 1874 appears red 0 In this theory there are four primary colors that member of the pair as opponents RE D is paired with its opponent B E is paired with its opponent o If one member of a pair is strongly stimulated the other member is inhibited Reason why there are no reddishgreens or bluishyellows o Afterimages occur when a visual sensation persists for a brief time after the original stimulus is removed 0 Contained in the thalamus In an area called the Lateral geniculate nucleus LGN Part of the pathway that visual information takes to the occipital lobe slim pallitUldE Color Blindness o Caused by defective cones in the retina 0 Three kinds of colorde cient vision 1 Monochrome color blindness 6 People either have no cones or have cones that don t work at all 6 Shades of gray 2 Dichromatic vision 6 One cone that does not work 0 Sexlinked inheritance o Colorde cient gene is recessive o Linked to the X chromosome Because males have one X and one Y chromosome they are more likely to have a colorde ciency compared to females two X chromosomes The Hearing Sense Can You Hear Me Now Perception of Sound Lee eler Seendr Lewer Piteh Setter Eeunldf Higher Filth ii Sound Waves Sound waves 0 Vibrations of the molecules of air that surround us 0 Same properties of light wavelength amplitude purity Wavelength interpreted by the brains as frequency or pitch Amplitude interpreted as volume how loud or soft a sound is Purity is called timbre in sound a richness in the tone of the sound 0 Seldom hear pure sounds 0 Range of frequencies humans can hear Measured in cycles waves per second also known as hertz Hz Limits between 20 and 20000 Most sensitivity from about 2000 to 4000 Hz 139ain three he39lld Feltentiel eararna e The Structure of the Ear Decibels 39 39 l l l 135 Hea dphenee ferried te higheet eellu me 125 Jae ltll ian39irner El feet awe ii Eeunt a ueea pain 1113i Liee reek meeie IEI Chain eaw er eu zlwany train geing leg 2 fee away iz F39relengeel eepeere be any mun abeee the level eeu ee hearing li 39ii We i39u i ELlUll39l39ll cleaner El Herma een eereatien between perigee 3 feet apart ee Quiet eifiee Librefe 15 Hermal lure thin The Outer Ear o Pinna the visible external part of the ear Serves as a kind of concentrator Funnels the sound waves from the outside into the structure of the ear 0 Auditory canal ear canal the short tunnel that runs down to the tympanic membrane eardrum The Middle Ear 0 Hammer mallet gt COIIeCtively referred to o Anvil incus as the ossices o Stirrup stapes gt Smallest bones in the The Inner Ear human body 0 Oval window gt Vibration ampli es 39 Membrane vibrations from the 39er ear Its vibratior eardrum iithin the inner ear 0 Cochlea Snailshaped structure lled with uid 0 Basilar membrane Surrounded by the cochlea s uid 0 Organ of Corti Rests in the basilar membrane Contains the receptor cells for hearing Hair cells on the organ receptors for sound 0 Auditory nerve Contains the axons of all the receptor neurons rmH Hearing In ELIE Slap32 7 IiiEMS r r ii Both are right to a point Place Theory to be correct the basilar membrane he to vibrate unevenly does at a frequency about 1000 Hz Frequency Theory to be correct the neurons associated with the hair cells would Perceiving Pitch Place theory 0 Oldest theory of how the brain receives information about pitch 0 Based on an idea proposed by Hermann von Helmholtz 1863 later elaborated on and modi ed by Georg von Bekesy 0 States that the pitch a person hears depends on where the hair cells that are stimulated are located Frequency theory 0 Developed by Ernest Rutherford 1886 0 States pitch is related to how fast the basilar membrane vibrates Faster the vibration the higher the pitch Slower the vibration lower the pitch 0 All of the auditory neurons would be ring at the same time KVolley Principle 0 Developed by Ernest Wever and Charles Bray 0 Accounts for pitches from about 400 Hz up to about 4000 0 Groups of auditory neurons take turns ring Process called volleying have to re as fast as the basHar membrane vibrates does of Hearing Impairments Hearing Impairment refers to dif culties in hearing n nlI I nnn Conduction Hearing Impairment 0 Problems with the mechanics of the outer or middle ear 0 Means that sound vibrations cannot be passed from the eardrum to the cochlea 0 Cause may be damaged eardrum or damage bones usually from infection Nerve hearing impairment 0 Also known as sensorineural hearing loss 0 Problem in either the inner ear or the auditory pathways and cortical areas in the brain Nerves or the brain 0 Sometimes xed with a cochlear implant Sends signals from a microphone to a sound processorlj translates those signals into electrical stimuli sent to implanted electrodes Chemical Senses Gustation Taste is one of our earliest developed senses Taste buds 0 Taste buds are taste receptors responsible for the sense of taste known as gustation 0 Most located on tongue but some found on roof of mouth cheeks under the tongue and in the throat Amount of taste buds vary for each individual Papillae the bumps which are lined by taste buds Each taste bud has about 20 receptors Receptors are replaced every 10 to 14 days The sense of scents olfaction o Olfaction the ability to smell odors Olfactory receptor cells 0 Contain cilia quottiny hairsquot o Replaced every 5 to 8 weeks 0000 Somesthetic Senses quotbody sensesquot Skin senses 0 Touch pressure temperature pain 0 Types of sensory receptors in the skin Pacinian corpuscles Respond to changes in pressure Beneath the skin Free nerve endings Respond to changes in temperature and to pressure and pain 0 Types of pain Visceral Pain in the organs Somatic pain 0 Pain in the skin muscles tendons and joints 0 Pain disorders Congenital analgesia and congenital insensitivity to pain with anhidrosis CIPA Inability to feel pain Affect neural pathways that carry pain heat and cold sensations Phantom limb pain 0 When a person who has had an arm or leg removed quotfeelsquot pain in the missing limb 0 Pain Gate Control Theory The pain signals must pass through a gate located in the spinal cord Activity of gate can be closed by nonpain signals Not a physical structure Substance P o A neuromodulator released by the pain receptor cells due to stimulation Activates other neurons Kinesthetic sense 0 Location of body parts in relation to each other Vestibular senses 0 Movement and body position 0 Otolith organs tiny sacs found above the cochlea Contain gelatinlike uid within which tiny crystals are suspended When the head moves the crystals cause the uid to vibrate Tells the person they re moving forward backward sideways or up and down 0 Semicircular canals three somewhat circular tubes Filled with uid that stimulates hairlike receptors when rotated o Sensory con ict theory Explanation of motion sickness Perception The Constancies size shape and brightness Size consistency o Tendency to interpret an object as always being the same size regardless of its distance from the viewer Shape consistency o Tendency to interpret the shape of an objects as constant Brightness consistency o Tendency to perceive the apparent brightness of an object as the same even when the light conditions change The Gestalt Principles Figureground relationships 0 Refer to the tendency to perceive objects or gures as existing on a background 0 Reversible gures gure and the ground seem to switch back and forth Proximity 0 Tendency to perceive objects that are close to one another as part of the same grouping Similarity o Tendency to perceive things that look similar as being part of the same group Closure o Tendency to complete gures that are incomplete Con nuty o Tendency to perceive things as simply as possible with a continuous pattern rather than with a complex brokenup pattern Con guty o Involves not just nearness in space but nearness in time also 0 Tendency to perceive two things that happen close together in time as being related in rmity ism I i vi Depth Perception capability to see the world in three dimensions Monocular cues also known as pictorial depth cues o A cue for perceiving depth requiring the use of only one eye 1 Linear perspective tendency for lines that are actually parallel to seem to converge a ie when looking down a long highway the two sides seem to merge in the distance 2 relative size when objects that people expect to be of a certain size appear to be small and are therefore are assumed to be much further away a ie movie makers using small models and making them seem gigantic using distance 3 overlap if one object seems to be blocking another object people assume the blocked object is behind the rst therefore it s farther away a also known as interposition 4 Aerial autmospheric perspective father away an object is the hazier the object will appear to be due to tiny particles of dust dirt and other pollutants in the air a Reason why mountains often look fuzzy 5 Texture gradient as you look farther off into the distance a texture becomes smaller and ner a le large expanses of pebbles rocks or patterned roads 6 Motion parallax discrepancy in motion of near and far objects a ie objects outside of a moving car seem to zip by very fast when they are close to the car and objects in the distance seem to move slower 7 accommodation makes use of something that happens inside the eye Binocular cues o A cue for perceiving depth requiring the use of both eyes 1 Convergence the rotation of the two eyes in their sockets to focus on a single object a If the object is close the convergence is great if object is far convergence is much less 2 Binocular disparity scienti c way of saying that because the eyes are a few inches apart they don t see the exact same image Perceptual Illusions Illusion a perception that does not correspond to reality The Hermann Grid IIIl iliif II III MullerLyer Illusion distortion happens when the viewer tries to determine if two lines are exactly the same length The Moon Illusion the moon on the horizon appears to be much larger than the moon in the sky Illusions of motion Other Factors That In uence Perception Perceptual setperceptual expectancy o People s tendency to perceive things a certain way because their previous experiences or expectations in uence them Way people interpret what they perceive can also in uence their perception Topdown processing 0 Use of preexisting knowledge to organize individual features into a uni ed whole 0 A form of perceptual expectancy Bottomup processing 0 Analysis of smaller features and building up to a complete perception o No expectancy to help organize the perception
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'