PSY 456: Exam 3 Study Guide
PSY 456: Exam 3 Study Guide PSY 456
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This 23 page Study Guide was uploaded by Brianna on Monday April 11, 2016. The Study Guide belongs to PSY 456 at Colorado State University taught by Amberg in Spring 2016. Since its upload, it has received 22 views. For similar materials see Sensation & Perception in Psychlogy at Colorado State University.
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Date Created: 04/11/16
Sensation & Perception Unit 3 Study Guide Chapter 9 Terms: ● Achromatic Colors: contain no hue ● Reflective Curves: percentage of light reflected for specific wavelengths to perceive color ● Selective Reflection: certain colors are selected to be reflected back ● Trichromatic Color Vision: 3 wavelengths ● Anomalous Trichromat: 3 wavelengths in different proportions than normal trichromat ● Dichromatic Color Vision: 2 wavelengths ● Unilateral Dichromat: trichromatic vision in one eye and dichromatic in the other ● Monochromatic Color Vision: 1 wavelength ● Chromatic Adaptation: prolonged exposure to chromatic color leads to receptors ● The Ratio Principle: areas that reflect different amounts of light look the same if the ratios of their intensities are the same ● Trichromatic Theory of Color Vision: three different receptor mechanisms responsible for color vision ● OpponentProcess Theory of Color Vision: color vision is caused by chemical reaction of opposing responses ● Penumbra: fuzzy border at edge of a shadow ● Reflectance Edge: edge where the reflectance of two surfaces changes ● Illumination Edge: an edge where the lighting changes Function of Color ● classify and identify objects ● organize elements into objects ● foraging What colors do we see? ● 250 Colors ● Primary ○ red, yellow, blue ● Secondary ○ created by combining 2 primaries ● Intermediate or Tertiary ○ created by combining primary with secondary ● Achromatic Colors ○ white, gray, black ● Why is there variety? ○ colors are changed by ■ Intensity: changed perceived brightness ■ Saturation: adding white to a color results in less saturated color Color and Wavelength ● Color perception is related to wavelength of light ○ 400450 nm violet ○ 450490 nm blue ○ 500575 nm green ○ 575590 nm yellow ○ 590620 nm orange ○ 620700 nm red ● Wavelengths ○ short: blue ○ medium: green ○ long and medium: yellow ○ long: red ○ long, medium & short: white ● Selective Transmission ○ transparent objects selectively allow wavelengths to pass through ● Simultaneous Color Contrast ○ background of object can affect color perception ● Colors of Objects ○ color of objects is determined by the wavelengths that are reflected ○ Reflective Curves: percentage of light reflected for specific wavelengths to perceive color ■ Selective Reflection: certain colors are selected to be reflected back ● Additive Color Mixture ○ mixing lights of different wavelengths ○ all wavelength available to observer ○ superimposing blue and yellow lights leads to white ● Subtractive Color Mixture ○ mixing paints with different pigments ○ additional pigments reflect fewer wavelengths ○ mixing blue and yellow leads to green ■ blue and yellow have green wavelength, red and blue wave cancels out Trichromatic Theory of Color Vision ● Behavioral Evidence (Young & Helmholtz) ○ ColorMatching Experiments ■ observers adjusted amounts of 3 wavelengths in a comparison field to match a test field of one wavelength ■ Results: ● “normal” color vision: three wavelengths ● color deficient: two wavelengths ● Physiological Evidence ○ measured absorption spectra of visual pigments in receptors ○ found receptors that responded maximally to ■ short wavelengths (419 nm) ■ medium wavelengths (531 nm) ■ long wavelengths (558 nm) ● Summary ○ color perception is based on response of three different cone types ■ responses vary depending on wavelengths available ● Are three receptors necessary for color vision? ○ one receptor type (monochromat) cannot lead to accurate color vision ■ absorption of a photon causes the same effect no matter the wavelength ■ any 2 wavelengths can cause the same response by changing the intensity ○ two receptor types (dichromats) solve this problem ○ three receptor types (trichromats) allow for perception of more colors Color Deficiencies ● Trichromatic Color Vision: 3 wavelengths ● Anomalous Trichromat: 3 wavelengths in different proportions than normal trichromat ● Dichromatic Color Vision: 2 wavelengths ○ Three Types ■ Protanopia (redgreen) ● affects 1% of maes and .02% of females ● individuals see short wavelengths as blue ● neutral point occurs at 492 nm ● above neutral point, see yellow ● missing the long wavelength pigment (red) ■ Deuteranopia (redgreen) ● affects 1% of males and .01% of females ● see short wavelengths as blue ● neural point occurs at 498 nm ● above neutral point, see yellow ● missing medium wavelength pigment (green) ■ Tritanopia (blueyellow) ● affects .002% of males and .001 of females ● see short wavelengths as blue ● neutral point occurs at 570 nm ● above neutral point, see red ● missing short wavelength pigment (blue) ● Unilateral Dichromat: trichromatic vision in one eye and dichromatic in the other ● Monochromatic Color Vision: 1 wavelength (truly color blind) ○ 4 types ○ very rare hereditary condition ○ only rods, no functioning cones ○ only perceive white, gray, and black tones ○ poor visual acuity ○ very sensitive to bright light ● Test with Ishihara Test OpponentProcess Theory of Color Vision ● Proposed by Hering ○ color vision is caused by opposing responses ■ blue and yellow ■ green and red ○ result of chemical reaction in the retina ● Behavioral Evidence ○ color afterimages and simultaneous color contrast show the opposing paring ○ types of color blindness are red/green and blue/yellow ● Physiological Evidence ○ researchers performing singlecell recordings found opponent neurons ○ Opponent Neurons ■ in retina and LGN ■ excitatory response to one end of the spectrum ■ inhibitory response to other end Trichromatic and Opponent Process Theories combined ● each describes physiological mechanisms ○ trichromatic theory explains responses of cones in retina ○ opponent process theory explains neural response for cells further in the brain Color in the Cortex ● there is no single module for color perception ○ cortical cells in V1 and V4 respond to some wavelengths or have opponent response cells usually also respond to forms and orientations ○ cortical cells that respond to color may also respond to white ● Types of Opponent Neurons in the Cortex ○ SingleOpponent Neurons ■ looking at larger scope, responds strongly to specific wavelength and inhibits others ○ DoubleOpponent Neurons ■ looking at boundaries, responds to more than one specific wavelength Color Constancy ● perception of colors as relatively constant in spite of changing light sources ○ sunlight has approximately equal amounts of energy at all visible wavelengths ○ tungsten lighting has more energy in the long wavelengths ○ objects reflect different wavelengths from these two sources ● Chromatic Adaptation: prolonged exposure to chromatic color leads to receptors ○ adapting when the stimulus color selectively bleaches a specific cone pigment ○ decreasing in sensitivity to the color ○ adaptation occurs to light sources leading to color constancy ● Uchikawa ○ shown sheets of colored paper in three conditions ■ Baseline: paper and observer in white light ■ Observer not Adapted: paper illuminated by red light; observer in white ■ Observer Adapted: paper and observer in red light ○ Results: ■ baseline: paper is green ■ not adapted: paper is slightly red ■ adapted: paper is yellowish ● Effect of Surroundings ○ color constancy works best when an object is surrounded by many colors ● Memory and Color ○ past knowledge of an object’s color can have an image on color perception ● Hansen ○ saw photographs of fruits with characteristic colors against a gray background ■ they adjusted the color of the fruit and a spot of light ■ when the spot was adjusted to physically match the background, the spot appeared gray ■ but when the color of the fruits was changed to the color of background, they were still perceived as being colored ● Lightness Constancy ○ perceived as remaining relatively constant ○ Perception of Lightness ■ is not related to the amount of light reflected by an object ■ is related to the percentage of light reflected by an object ○ The Ratio Principle ■ this works when objects are evenly illuminated ○ Lightness Perception under Uneven Illumination ● Information in Shadows: system must determine that edge of a shadow is an illumination edge and not a reflectance edge ○ system takes into account objects meaningfulness ○ penumbra of shadows signals an illumination edge ● Orientation of Surfaces ○ A. when viewing full image, easier to determine if you are seeing an illumination edge or reflectance edge ○ B. when viewing only parts of an object, more likely to see shadows as reflectance edge Color is a Construction of the Nervous System ● physical energy in the environment does not have perceptual qualities ○ light waves are not colored ● different nervous systems experience different perceptions ● honeybees perceive color outside of human perception Infant Color Vision ● difficult to know what an infant sees, can’t get verbal feedback ○ chromatic color ○ brightness ● Bronstein et al ○ habituation ○ young infants have color vision ■ can perceive color and changes in brightness Chapter 10 Terms: ● Interoception: the sense of the physiological condition of the body ● Affordances: the relation between an object/environment that affords the opportunity to perform an action ● End State Comfort Effect: how you approach a task depends on how easy the end result of the task will be Depth and Size Perception ● Allows us to ○ reach out and grab an objects seamlessly ○ catch/block objects thrown at us ○ know, understand, and interact with our environment How do we get Depth Information? ● Monocular ○ Pictorial Cues ■ Occlusion ● things that are close to you overlap those that are further away ■ Relative Height ● objects higher on horizon appear bigger/further away ■ Relative Size ● things that are smaller appear further away ■ Linear Convergence ● convergence of parallel lines make things seem like they’re receding (further away) ● Ames Window Illusion ■ Familiar Size ● things that you know the size of remain relatively the same size ■ Atmospheric Perspective ● things further away are less clear and distinct ■ Texture Gradient ● the more dense a texture is, the further away it is ■ Shadows ● we assume light comes from above which alters whether we perceive an object as coming towards us or moving away ○ Movement Cues ■ Motion Parallax ● we assume faces are convex not concave, so we perceive it as moving ● things moving quicker in relation to background appear closer ■ Deletion and Accretion ● deletion is background moving behind foreground ● accretion is foreground moving in front of background ● Binocular ○ Binocular Disparity ■ more discrepancy between both eyes means object is closer ■ how 3D works ○ Binocular Convergence ■ your eyes converge together to focus on closer objects ■ only reliable within 10 meters ○ Correspondence Problem ■ ensuring that the 2 separate retinal images produce a single percept of one point in space ■ when it goes wrong: double vision Size Perception ● Size Constancy ○ things that shrink over time are actually moving away ● Emmert’s Law ○ perception = (perceived size)/(perceived distance) ○ Moon Illusion ■ when the moon is closer to the horizon, we perceive it as closer in relation to other objects on the horizon ● Illusions How can we Study Perception? ● Verbal Estimates ○ people are inherently bad at estimating distances ● Visual Matching ○ determine when target object is same distance away as control object ● Action Measures ○ Blindwalking: walk distance to target object while blindfolded ○ Task Completion: throw beanbag a certain distance ● Hard to Study ○ can’t get end result ○ can’t get survey, people don’t always know what they see ○ can’t directly observe with imaging ActionSpecific Perception ● people perceive their surrounding environment in terms of their ability to act in it ● Size Distortions ○ asked softball players what size the ball was that they hit ■ Results: those with higher batting average saw the ball as bigger ○ asked field goal kickers how large they saw the goal ■ Results: ● those who miss left or right see goal as narrower ● those who miss below see goal as higher ○ golfers who play better see the hole as bigger ■ Ebbinghaus Illusion affected performance ● Spatial Distortions ○ we systematically perceive slants to be steeper than they are ■ 5 degrees appears to 18 degrees ■ 30 degrees appears to be 60 degrees ○ Distances on a hill ■ Optical ● tells us that distances are closer ■ Energetic ● see distances as further on hill than flat ● see distances as further after fatigue, with backpack, ● people who are obese perceive distances as further than those who aren’t ○ Real world ■ those who perceive the staircase as steeper are more likely to take elevator ○ Embodied Cognition ■ ability to act upon an object ■ swimmers with fins see distances as closer than those without ○ Fear ■ standing on hill on skateboard seems steeper than not ■ people with greater fear of spider see spiders as closer and with more malevolent intent ■ people who are more afraid of heights see hieghts as taller ● Speed Distortions ○ tennis players who are better at returning a serve see ball as moving slower ● Where are these Distortions ○ distortions have already occurred by time they reach primary visual cortex ○ intervention at LGN level ● Interoception ○ thought to play a background role in the regulation of various physiological processes ■ low interoceptive attunement is associated with greater susceptibility to the rubber hand illusion ● rubber hand illusion helpful in diminishing phantom limb pain ■ individuals who are better at perceiving their own heart rate, are better at modulating physical effort to match their physical abilities Affordances ● affordances always exist but we don’t always perceive them ● Affordance in Design ○ pull handles on push door ○ knob for gear shifting End State Comfort Effect ● individuals actions start before the action begins ● we plan for the action without being conscious of minute differences ● not great at perceiving our environment but we are good at perceiving the intention of actions Perception of action ● Biological Constraints ● Real World Application ○ Robotics ○ Military ○ Training for tool/mechanical use ○ Crime Reports ○ Environmental Design Chapter 14 Terms: ● Cutaneous Senses: perception from the skin ● Proprioception: position of body and limbs ● Kinesthesis: movement of body and limbs ● Epidermis: outer layer of skin ● Dermis: below epidermis ● Mechanoreceptors: responsible for tactile perceptions ● Pacinian Corpuscle: primarily responsible for sensing vibration ● Duplex Theory of Texture Perception: belief that two receptors are responsible for texture perception ● Inflammatory Pain: damage to tissues and joints or by tumor cells ● Neuropathic Pain: damage to the central nervous system ● Nociceptive: signals of impending damage to the skin ● Medial Lemniscal Pathway: large fibers carry proprioceptive (where body is) and touch information ● Spinothalamic Pathway: smaller fibers carry temperature and pain information ● Direct Pathway Model: nociceptors are stimulated and send signals to the brain ● Gate Control Model: signals from additional pathways can act to open or close a gate which determines the strength of the signal leaving the spinal cord ● Active Touch: touch in which a person actively explores an object ● Passive Touch: occurs when touch stimuli are applied to the skin ● Exploratory Procedures: movements of hands and ﬁngers while identifying 3D objects by touch Somatosensory System ● Three Parts ○ Cutaneous Senses ○ Proprioception ○ Kinesthesis Cutaneous System ● Skin ○ Protects: keeps agents from penetrating body ○ Epidermis: dead skin cells ○ Dermis ■ Mechanoreceptors ● Shallow ○ Merkel Receptor ■ fires continuously while stimulus is present ■ responsible for sensing fine details ○ Meissner Corpuscle ■ fires when stimulus is first applied and removed ■ responsible for controlling hand grip ● Deeper ○ Ruffini Cylinder ■ fires continuously to stimulation ■ perceives stretching of skin ○ Pacinian Corpuscle ■ fires when stimulus first applied and removed ■ associated with sensing rapid vibrations and fine texture ○ Pathways from Skin to Cortex ■ nerve fibers travel in bundles to the spinal cord ■ Two major Pathways ● Medial Lemniscal Pathway: large fibers carry proprioceptive (where body is) and touch information ● Spinothalamic Pathway: smaller fibers carry temperature and pain information ● they cross over to the opposite side of the body and synapse in the thalamus ■ Somatosensory Cortex ● signals travel from the thalamus to the somatosensory receiving area (S1) and the secondary receiving area (S2) in the parietal lobe ● body map (homunculus) allocation of senses ○ plasticity in neural functioning leads to multiple homunculi ○ changes allocation of cortical cells Perceiving Details ● Measuring Tactile Acuity ○ TwoPoint Threshold: minimum separation between points to perceive as separate ○ Grading Acuity: indicate the orientation of the rating ○ Raised Pattern Identification: using patterns to determine the smallest size that can be identified ● Receptor Mechanism for Tactile Acuity ○ high density of Merkel receptors in the fingertips ■ densely packed on the fingertip ○ body areas with high acuity have larger areas of cortical areas in brain devoted to them ■ also have smaller receptive fields on the skin Perceiving Vibration ● Pacinian Corpuscle (PC) primarily responsible for sensing vibration ○ fibers without the PC only respond to continuous pressure Perceiving Texture ● Duplex Theory of Texture Perception ○ Katz proposed that perception of texture depends on two cues ■ Spatial Cues: size, shape, and distribution of surface elements ■ Temporal Cues: rate of vibration as skin is moved across finely textured surfaces Perceiving Objects ● active touch to interact with the environment ● Haptic Perception: active exploration of 3D objects with the hand ○ Three Systems ■ Sensory System ■ Motor System ■ Cognitive System ● Psychophysical Research ○ people can identify objects haptically in one to two seconds ○ Klatzky et al. ■ shown that people use Exploratory Procedures ● Lateral Motion ○ used to judge texture ● Contour Following ○ used to judge shape and texture ● Pressure ● Enclosure ○ used to judge shape ● Physiology ○ firing pattern of groups of mechanoreceptors signal shape ○ neurons further upstream, more specialized Pain ● Multimodal Phenomenon ○ Sensory Component ○ Emotional (Affective) Component ● Three Types ○ Inflammatory Pain: damage to tissues and joints or by tumor cells ○ Neuropathic Pain: damage to the central nervous system ■ brain damage caused by stroke ■ repetitive movements ● carpal tunnel syndrome ○ Nociceptive: signals of impending damage to the skin ■ transmit pain signals to the spinal cord and brain ■ some respond to heat, chemicals, pressure, cold ■ threshold of receptor warns of damage, but not affected by normal activity ● The Brain and Pain ○ Pain Matrix ■ Subcortical Areas ● hypothalamus, limbic system, thalamus ■ Cortical Areas ● S1, insula, anterior cingulate, prefrontal cortices ○ Hoffauer et al ■ presented with potentially painful stimuli and asked to rate ● pain intensity ● unpleasantness ■ brain activity measured while hands in hot water ■ hypnosis used to increase or decrease sensory and affective component ■ Results: ● suggestions to change subjective intensity changed ratings and S1 activity ● suggestions to change unpleasantness did not change subjective ratings, but did change ratings of unpleasantness ○ Opioids ■ opiate drug (i.e. heroin) overdoses can be revived with naloxone ● blocks site normally occupied by heroin ■ Endorphins ● act on same receptors as opiates ● evidence that endorphins reduce pain ○ injecting naloxone blocks the receptor sites causing more pain ○ naloxone also decreases the effectiveness of placebos ○ individuals who release more endorphins can withstand higher pain levels ● Direct Pathway Model (Early Model) ○ nociceptors are stimulated and send signals to the brain ○ Problems ■ pain can be affected by mental state and attention ■ pain can occur with no stimulation ■ phantom limbs ● Gate Control Model ○ “gate” consists of substantia gelatinosa cells in the spinal cord (SG and SG+) ○ input into the gate comes from ■ Large Diameter (L) Fibers: information from tactile stimuli (mechanoreceptors) ■ Small Diameter (S) Fibers: information from nociceptors ■ Central Control: information from cognitive factor from the cortex ● Cognition and Pain ○ Expectation ■ patients and pain medication ■ placebos ○ Shifting Attention ■ virtual reality ○ Content of Emotional Distraction ■ keep hands in cold water longer when shown positive pictures ○ Hypnosis (Derbyshire) ■ investigate hypnotically induced pain ■ thermal stimulator attached to the palm ■ 3 Conditions ● physically induced pain ● hypnotically induced pain ● control: imagined pain ■ Results: subjective reports & fMRI showed hypnosis produced pain perception The Effects of Observing Touch and Pain in Others ● Keyser et al. ○ being touched vs. watching people or objects being touched ○ Results: similar brain areas activated ● Meyer et al. ○ showed films of hands haptically exploring objects ○ Results: both visual and S1 areas activated ● Singer et al. ○ romantically involved couples participated ○ woman’s brain activity measured by fMRI ○ the women either received shocks or she watched partner receive shocks ○ Results: similar brain areas activated in both conditions Congenital Insensitivity to Pain ● Hereditary Sensory and Autonomic Neuropathy ● Mutations in the SCN9A gene ○ SCN9A gene provides instructions for making a sodium channel (NaV1.7) ○ NaV1.7 found in nociceptors: cause congenital insensitivity to pain ■ production of nonfunctional alpha subunits that cannot be incorporated into NaV1.7 channels ■ as a result, the channels are not formed Chapter 15 Terms: ● Filiform: shaped like cones and located over entire surface ● Fungiform: shaped like mushrooms and found on sides and tip ● Foliate: series of folds on back and sides ● Circumvallate: shaped like flat mounds in a trench located at back Chemical Senses: Gatekeepers of the body ● Identifies things that should be consumed for survival ● Detect things that would be harmful and should be rejected ● Cause good and bad affective responses Taste Qualities ● Five Basic Taste Qualities ○ Salty ○ Sour ○ Sweet ○ Bitter ○ Umami: meaty, brothy, or savory. associated with MSG ● The Taste System ○ Sweetness: substances that have nutritive value ○ Bitter: substances that are potentially harmful ○ Salty: presence of sodium ○ Structure ■ Papillae ● Filiform: shaped like cones and located over entire surface ● Fungiform: shaped like mushrooms and found on sides and tip ● Foliate: series of folds on back and sides ● Circumvilliate: shaped like flat mounds in a trench located at back ■ Taste buds are located in all papillae except filiform ● tongue contains 10,000 taste buds ● each tastes bud has 50100 taste cells with tips that extend into the taste pore ● transduction occurs when chemicals contact the receptor sites on the tips ■ Erickson ● rats shocked when drank potassium chloride ● when given the choice, avoided potassium chloride and drank sodium chloride ● the experiment provides physiological and behavioral evidence for distributed coding ■ Signals from taste cells travel along a set of pathways ● Chorda Tympani Nerve from front and sides of tongue ● Glossopharyngeal Nerve from back of tongue ● Vagus Nerve from mouth and throat ● Superficial Petronasal Nerve from soft palate ● pathways make connections in the nucleus of the solitary tract in the spinal cord then travel to thalamus ● followed by areas in the frontal lobe ○ insula ○ frontal opervulum cortex ○ orbital frontal cortex ● Specificity Coding ○ Mueller et al. ■ genetic cloning was used to determine if mice could be created that possessed a human receptor that responds to PTC ■ normally mice don’t have receptor or respond to this substance ■ experiment was successful but with varying results ○ Sato et al. ■ recordings were made from 66 fibers in the monkey’s chorda tympani ■ Results: ● there were fibers that responded best to one of the basic tastes, but poorly to the others ● thus, there are fiber that respond specifically to particular chemicals ○ Evidence exists for specificity and distributed coding ■ some researchers suggest that the neural system for taste may function like the visual system for color ■ currently there is no agreed upon explanation for the neural system for taste ● Individual Differences in Taste ○ there are different responses to phenylthiocarbamide (PTC) and to 6n propylthiouracil (PROP) ■ tasters, nontasters and supertasters ■ tasters have more taste buds than nontasters ● tasters have specialized receptors for these compounds ■ supertasters appear more sensitive to bitter substances than tasters Practice Exam Questions Chapter 9 1. describe the functions of color vision 2. discuss how wavelength, intensity, and saturation affect our color experience 3. explain how mixing yellow and blue paints yield green 4. describe how additive color mixing works 5. describe reflectance curves 6. discuss the basic principles of the trichromatic theory of color and the behavioral and physiological support for the theory 7. name and define the different types of color deficiencies and the physiological mechanisms of these deficiencies 8. discuss the basic principles of the opponentprocess theory of color and the evidence 9. define color constancy and explain how chromatic adaptation is related to color constancy 10. describe hot “topdown” processing can affect color perception 11. discuss 4 possible causes of lightness constancy 12. discuss color perception capabilities in human infants and difficulties measuring Chapter 10 1. what pictorial cues are used for depth perception? 2. what motion cues are used for depth perception? 3. what binocular cues are used for depth perception? 4. explain emmert's law 5. to what degree is perception of the world “real”? 6. how can action affect perception? 7. how can perception affect action? 8. what is the end state comfort effect? 9. what assumption do we make in regards to movement? Chapter 14 1. name and define the three parts of the somatosensory system 2. identify the functions of the skin 3. name and describe the four types of mechanoreceptors 4. describe the mapping of the sensory “homunculus” 5. describe methods used to measure tactile acuity 6. discuss what receptor mechanisms and cortical mechanisms are responsible for tactile acuity 7. discuss research that shows that PC fibers are important in feeling vibrations 8. describe the duplex theory of texture perception and supporting research for the theory 9. differentiate between active and passive touch and how each affects perception 10. explain how exploratory procedure are used in haptic exploration 11. discuss research on the physiology of tactile object perception 12. distinguish between the three different types of pain 13. address three problems with the direct pathway model of pain 14. discuss the major principles of the gatecontrol model of pain 15. discuss four cognitive factors that affect pain perception 16. explain how opioids, endorphins, and placebos affect the perception of pain 17. explain why pain is beneficial and describe congenital insensitivity to pain Chapter 15
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