PSY101_CHAPTER4_upload (1).pptx

Psychology: From Inquiry to Understanding 2/e Scott O. Lilienfeld Steven Jay Lynn Laura Namy Nancy J. Woolf Prepared by Caleb W. Lack This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmis...

Psychology: From Inquiry to Understanding 2/e Scott O. Lilienfeld Steven Jay Lynn Laura Namy Nancy J. Woolf Prepared by Caleb W. Lack This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or part, of any images; any rental, lease, or lending of the program. LECTURE PREVIEW  Sensation and perception  The visual system  The auditory system  The sensual sense  Our body senses 2 Chapter 4 SENSATION AND PERCEPTION: HOW WE SENSE & CONCEPTUALIZE THE WORLD SENSATION & PERCEPTION: TWO SIDES OF THE COIN o Sensation: the detection of physical energy by sense organs (e.g. eye, nose, skin etc.) o Perception: is the brain’s interpretation of raw sensory data. o Sensation  pick up signals in environment, Perception  assembles these signals into stg. meaningful. (illusions!) o 4 SENSATION & PERCEPTION: TWO SIDES OF THE COIN o How do signals that make contact with our sense-organs become translated into info. that our brains can interpret & act? Sensory systems  physical signals to neural activity. Brain  interpretation of neural activity. o Transduction: The external stimulus converted by sense receptor into neural activity. Light, sound  electrical signals 5 SENSATION & PERCEPTION: TWO SIDES OF THE COIN  Sensory activation greatest when we first detect a stimulus  Sensory adaptation: Sense receptor reacts strongly at first & then tamps down its level of responding to conserve energy & attentional resources Ex: you longer notice that you are sitting on a chair.  Psychophysics (Gustav Fechner,1860): the study of how we perceive sensory stimuli based on their physical characteristics 6 SENSATION & PERCEPTION: TWO SIDES OF THE COIN o Absolute threshold: the lowest level of a stimulus that can be detected when no other that type of stimuli is present (how sensative our sensory systems are). • A single candle 48 kms away • 50 odorant molecules o Just Noticeable Difference (JND): the smallest amount of stimulus change that we can detect. (How much difference in a stimulus makes a change) (stronger from weaker) o Weber’s Law; the stronger the stimulus, the greater change needed to detect. 7 8 SENSATION & PERCEPTION: TWO SİDES OF THE COİN o Signal detection theory (Green & Swets, 1966): How we detect stimuli under uncertain conditions? Ex: (you need to increase the signal(shout) over the static connection (background noise) while talking on the phone. o Signal-to-Noise Ratio: It becomes harder to detect a signal as background noise increases. o The sensation is determined by the nature of sense-receptor, not the stimulus o Phosphenes- vivid sense of light (sparks) caused by pressure on your eye’s receptor cells. ( no matter touch or light activated the sense receptor). Cross-Modal Senses : Phosphenes, the McGurk effect, the rubber hand illusion) 9 SENSATION & PERCEPTION: TWO SİDES OF THE COİN o McGurk Effect: integration of visual & auditory info. (our brain automatically calculate the most probable sound given by the info. from two sources. (ba-hearing, ga-video; experience of da). http://www.youtube.com/watch?v=jtsfidRq2tw o Rubber-Hand Illusion: how our senses of touch & sight interact to create a false experience. http://www.youtube.com/watch?v=sxwn1w7MJvk o This may help to explain synesthesia—hearing sounds when one sees colors or tasting colors; people experience cross-modal sensations. 10 WHEN SENSES MEET THE BRAIN o Our brains do not rely on what’s in our sensory field.  What’s in our sensory field; but also  What was there a moment ago  What we remember from our past o Parallel Processing: We attend to multiple senses at once (Bottom-up & Top-down )  Bottom-Up Processing: construction a whole stimuli from its parts (e.g. perceiving an object from its parts)  raw stimuli primary visual cortex  synthesizing into meaningful concept. association cortex. 11 WHEN SENSES MEET THE BRAIN  Top-Down Processing: processing the whole stimuli & by analyzing ends up with processing the smaller parts. association cortex  primary visual cortex. (work hand in hand ; e.g. ambigous figures). Depending on our expectations & beliefs we typically percieve these figures differently. o o (jazz musician) (woman face) Perceptual sets o tendency to perceive / notice some aspects of the available sensory data &ignore others 12 CAN YOU FIND THE DOG? 13 WHEN SENSES MEET THE BRAIN . H or A? B or 13? Old or young? 14 WHEN SENSES MEET THE BRAIN o Perceptual constancy: we perceive a stimulus consistently across varied conditions (adaptive!)  Shape constancy: we see a door as a door when shut, barely open or fully open.  Size constancy: percieve objects as the same size no matter how far away they are.  Color constancy: our ability to perceive color across different levels of lightening. o Color perception in particular derives from context! 15 16 17 http://www.youtube.com/watch?v=z9Sen1HTu5o 18 19 THE ROLE OF ATTENTION o Flexible attention ! (adaptive!) • Selective attention: allows us to choose which sensory inputs to focus on and which to “turn down” (RAS & the forebrain) • Cocktail Party Effect: we don’t typically notice what other people are saying at a party unless it’s relevant to us. (Experiment conducted by Simons & Chabris, 1999) http://www.youtube.com/watch?v=vJG698U2Mvo o Change-blindness- failure to detect obvious changes in the environment. 20 SEEING: THE VISUAL SYSTEM o Light (electromagnetic energy)! o Visible light  wavelenght in the hundreds of nanometers. (btw. ultraviolet & infrared) o Other animals may have a more restricted or greater spectrum; (e.g.; reindeer, butterflies; some birds & fish, bees) 21 SEEING: THE VISUAL SYSTEM o o When light reaches an object, some of that light gets reflected & some of gets absorbed. Brightness  intensity of the reflected light. White  reflect black  absorb Hue  the color of light. o Primary colors; red, green & blue  white (additive color mixing) o Primary colors; yellow, cyan, magenta black (subtractive color mixing ) 22 STRUCTURE OF THE EYE o   Different parts of our eye The Sclera: the white portion; protective layer The Iris: colored part of the eye (e.g. blue, brown, green/ hazel) • •  two pigments (melanin/ brown & lipochrome/ yellowish brown) controls amount of the light The Pupil: the hole where light enters the eye.  Pupil contradiction  the amount of light Pupil dilation  the amount of light   Psychological significance  complex info., arousal & excitement & attractiveness  belladonna 23 24 STRUCTURE OF THE EYE  The Cornea: transparent cells ; focus/bends light on the back of the eye (retina). • •  Fixed The Lens: changes curvature (accommodation) to focus light onto back of eye (retina). • • o Curved, transparent layer Consists of cells completely transparent. Bends the light, changes (adaptation to distance) The lens  flat (distant objects) fat (nearby objects)  accomodation 25 26 STRUCTURE OF THE EYE  Glasses change the way light enters the eye to help correct myopia or hyperopia;       Myopia (nearsightedness)- ability to see near objects & inability to see distant objects. results when images are focused in front of the eye (retina), or our eyes are too long. Hyperopia (far-sightedness)- ability to see distant objects & inability to see near objects. results when images are focused behind the eye (retina), or our eyes are too short. Age  Vision  https://www.youtube.com/watch?v=YcedXDN6a88 27 STRUCTURE OF THE EYE  The retina: thin membrane at the back of the eye.    Rods- basic shapes & forms of the objects low (dim light)     cell-receptors for vision & neurons The fovea; for acuity or sharpness of vision (fine detail). Dark adaptation; from bright  to dark environment. Rods should regain their maximum sensitivity to light. No rods in the fovea; we can see the star better by not looking directly Cones- gives the color vision & sensitive to detail   (also active in reading) require more light 28 29 STRUCTURE OF THE EYE  The optic nerve: retina cells bundle all axons together & depart the eye to reach the brain (back of the eye)  From retina to the rest of the brain.  optic chiasm; half of the axons cross optic chiasm & other half stays on the same side.  Most of the axons go to the thalamus and then the visual cortex, but some go to midbrain (play a key role in reflexes)  Blind spot; the place where optic nerve connects to retina https://www.youtube.com/watch?v=JRxdFuPSp98 30 31 32 33 Thalamus  occipital lobe  assoc. cortex of the pariatal lobe (visual form, motion, position) assoc.cortex of the temporal lobe (form & color). 34 MOTION PERCEPTION 35 MOTION PERCEPTION o To determine motion, the brain compares visual frames of what is to what was. o Phi phenomenon: the optical illusion of perceiving continuous motion btw. separate objects viewed rapidly in succession. o Defined by Max Wertheimer (1912) (cinema & animation) a series of adjacent light flashed on/ off in succession. 36 37 GESTALT PRINCIPLES o o o Rules that govern how we perceive objects as wholes within their overall context. Gestalt principles why we see much of our world as consisting of unified figures or forms Formulated by Wertheimer, Kohler & Koffka in the early 20th century. 38 DEPTH PERCEPTION o o Depth perception; ability to see spatial relations in three dimensions. Depth perception  idea of how close & far the objects. o Two kinds of cues;   Monocular depth cues: one eye  Relative size, texture gradient, interposition, linear perspective, height in plane, light & shadow. Binocular depth cues: both eyes  Binocular disparity & binocular convergence. DEPTH PERCEPTION o Monocular depth cues: pictorial cues o Relative Size: more distant objects look smaller. Texture Gradient: The texture of objects become less apperent as objects move farther away. Interposition: When one object blocks our view of an object, we understand which object is closer / farther away. Linear Perspective: The outline of rooms & buildings converge as distance increases. Two parallel lines (vanishing point) ! Height in Plane: Distance objects seem higher & nearer objects lower. Light & Shadow: Objects cast shadows a sense of their three dimensional form. o o o o o o o Motion Parallax; the ability to judge the distance of objects from their speed 41 DEPTH PERCEPTION o o o o o Binocular depth cues: we can view each of our two visual fields with both eyes. info. sent from both sides compared  binocular depth perception. Binocular Disparity: our right & left eyes  different info. for near objects but see distant objects similarly. Each eye sees the world a bit differently & brain uses this info to judge the depth & place of the objects. Binocular Convergence: nearby objects eye muscles turn eyes inward; our brains are aware of how much our eyes are converging (estimates distance). Depth Perception begins in infancy (6-14 months) when we learn to crawl (Visual cliff studies). WHEN PERCEPTION DECEIVES US o We often misperceive information around us o Moon illusion: the moon appears larger on the horizon than high in the sky. o Ames Room illusion: a distorted room (trapezodial) . - Relative size & the height of the ceiling - L.O.T.R. - Charlie & the Chocolate Factory WHEN PERCEPTION DECEIVES US o Muller-Lyer illusion: line with arrowheads pointing inward > line with arrowheads pointing outward. o Ponzo illusion: when converging lines enclose two objects of identical size the object closer to the converging line > the object far way to the converging line . WHEN PERCEPTION DECEIVES US o Horizontal-vertical illusions: vertical part of > horizontal part, o Ebbinghaus-Titchner illusions: circle when surrounded by small circles > circle when surrounded by bigcircles. WHEN WE CAN’T SEE o o Blindness: inability to see Blind people  heightened sense of touch (visual cortex  sensitive to touch) o Color Blindness: can not see all the colors, results from the absence or reduced number of one or more types of cones. o Motion blindness—inability to perceive seamless motion. (damage to occipital cortex & Alzheimer's disease) o Visual agnosia—object recognition deficit; damage to visual cortical areas & parietal lobe. HEARING o o o o Audition; sense of hearing Sound  vibration (mechanical energy) traveling through a medium (air). Vibration of molecules of air  sound waves. Sound has;  Pitch: wave frequency (Hz);vibration per second higher frequency  higher pitch ; lower frequency  lower pitch (people  20 to 20.000 Hz).  Loudness: amplitude or the height of the sound waves (dB). Loud noise  increased wave amplitude (more disturbance & more vibrating airborne molecules). (0-85 Db)   Timbre: complexity& quality of sound. Different musical instruments have different timbre. HEARING 48 THE EAR o o  o o o o Ear ; sense receptors sound  neural activity. The outer ear, middle ear & inner ear. The outer ear: pinna & ear canal. Funnels sound waves onto the eardrum The pinna  direct sound through the ear canal to the tympanic membrane (eardrum). Eardrum (tympanic membrane): is a thin, coneshaped membrane Vibrates in response to sound waves & transmits sound to middle ear. 50 THE EAR  Middle Ear: contains the ossicles (hammer, anvil & stirrup) vibrate at the frequency of the sound wave sound middle ear  to the inner ear  Inner ear: sound detection & balance. cochlea, & vestibular system. Cochlea; vibration  neural activity sound pressure  electrochemical impulses  brain (auditory nerve) Organ of Corti & Basilar Membrane.    52 53 THE EAR  Organ of Corti & Basilar Membrane  Organ of Corti; transduction of sound vibration pressure electrochemical impulses  brain via the auditory nerve.    o Basilar Membrane: hair cells or auditory sensory cells. specialized structures that respond to fluid-borne vibrations btw. 15,000-20,000 auditory nerve receptors. Different tones  different areas of the basilar membrane &auditory cortex PITCH PERCEPTION o The primary auditory cortex  different tones in different places (info. from different part of basilar membrane PITCH PERCEPTION o o o o Different tones  different areas of the basilar membrane &auditory cortex Place theory Hair cells  base of basilar membrane (high-pitched tones). Hair cells  the top of the basilar membran (low-pitched tones) auditory nerve  to brain  to thalamus;  to auditory cortex o The info. arrive at brain stem at different times; the brain uses this to locate the source of the sound. o Vestibular system: balance & movement & spatial orientation (Semicircular canals) . https://www.youtube.com/watch?v=PeTriGTENoc 58 WHEN WE CAN’T HEAR o About 1 in 1000 people are deaf & many others suffer from hard of hearing. o Deafness may result from; o Malfunctioning of ear (failure of eardrum or ossicles to vibrate) o Damage to auditory nerve & auditory cortex o Exposure to lound sounds for a long time (hair cells in the organ of corti is damaged) SMELL AND TASTE o Olfaction (smell) & gustation (taste): work hand in hand. (liking/disliking of some foods) . o chemical senses: sensory experience drived from the chemicals in substances. Smell  odors; taste  flavors o Animals  tracking preys, establishing territories & recognizing the opposite sexs. o An avarage dog is 100.000 times more sensitive to smell than humanbeings. o Function of smell & taste  sample our food before swallowing it (survival!) ODORS AND FLAVORS o Odors  airborne chemicals (odorant chemicals) interacting with olfactory neurons w/ sense receptors in our nasal passages.  Our nose  2000-4000 different odors   We can detect only a few tastes;  Sweet, salty, sour, bitter, umami (meaty) Each olfactory neuron contains  a single type of receptor, (odorant shape, lock & key)  (450 types) Transduction Odorants  olfactory receptors  action potentials SMELL AND TASTE SENSE RECEPTORS 63 ODORS AND FLAVORS  Odors  sense receptors  olfactory bulb  limbic system (hypothalamus, amygdala, hippocampus) & olfactory cortex (temporal lobe)  orbitafrontal cortex 65 ODORS AND FLAVORS  Odors  sense receptors  olfactory bulb  limbic system (hypothalamus, amygdala, hippocampus) & olfactory cortex (temporal)  orbitafrontal cortex SMELL AND TASTE o o Humans detect taste with taste buds, the bumps on the tongue called papillae. Papillae  numerous taste buds. Taste buds specific to   Sweet Bitter Sour Salty Umami ODORS AND FLAVORS o o o Chemicals bind to taste buds (gustotary cells) (transduction!) Taste buds  cranial nerves  thalamus  gustatory cortex  orbitafrontal cortex (smell & taste converge) Also  limbic system (amydala, hypothalamus & hippocampus) & somatosensory cortex 69 OLFACTORY AND GUSTATORY PERCEPTION o Babies can identify their mother’s odor & siblings can recognize each other on the basis of odor. o Women can tell whether people just watched a happy or sad movie from samples of armpit odor. o Supertasters; people oversensitive to certain tastes (abundance of taste buds). http://www.youtube.com/watch?v=8pCSVtwAZpE http://www.youtube.com/watch?v=WavjbJhiRAE OUR BODY SENSES o Three body systems that work in tandem;  Somatosensory (touch, temperature and pain)  Proprioception (kinesthetic sense); body position sense.  Vestibular sense (equilibrium and balance) SOMATOSENSORY SYSTEM o Somatosensory System: stimuli applied to skin; pressure, light touch, temperature, & (chemical) injury that produces pain. o o specialized nerve endings (mechanoreceptors)  temperature, pressure free nerve endings  pain, high heat Free nerve ending Light touch Skin stretching Deep pressure SOMATOSENSORY SYSTEM o Pain causing stimulus; thermal; chemical or mechanical. (Each has a threshold) o People differ in pain thresholds (people w/ red hair- more sensitive to pain) o Phantom limb: the sensation that an amputated or missing limb is still attached to the body &feeling of pain or discomfort in the missing limb. 1) Maladaptive changes in the primary sensory cortex after amputation (maladaptive plasticity) 2) Result of "junk" inputs from the peripheral nervous system o Pain insensitivity: inability to feel pain (exceedingly dangerous) SOMATOSENSORY PATHWAYS o Touch info. travels more quickly than the pain info. Somatic nerves carry info to spinal cord Connects in brain stem; Spinal reflexes may be activated Thalamus Touch: somatosensory, motor cortex, association cortices o Emotions are also involved in pain perception. OR Pain: somatosensory cortex, limbic areas, frontal cortex 76 BODY POSITION & BALANCE o Proprioception; our kinesthetic sense, helps us keep track of where we are and move efficiently o Proprioceptors (muscles, skin & joints) o The sense of the relative position of parts of the body & strength of effort being employed in movement. (even if our eyes are closed) BODY POSITION & BALANCE o Proprioceptors  spinal cord  brain stem (reflexes)  thalamus  somatosensory & motor cortex. cerebellum BODY POSITION & BALANCE o Vestibular system: balance & movement & spatial orientation o Semicircular canals  contain fluid & “sensors” that detect rotational movement of the head. Each semicircular canal  different movement: up/down/side-to side. o BODY POSITION & BALANCE BODY POSITION & BALANCE Vestibular system: Sensory hair cells  vestibular nerve  brain o Sensory hair cells  vestibular nerve  brain stem (reflexes) & cerebellum (to catch our balance when falling) o Awareness occurs only balance is lost or experience dramatic mismatches btw. visual input & vestibular inputs. (dizziness & nausa)