1. Copyright © 2016 Pearson Education, Inc. All Rights Reserved CHAPTER 3 SENSATION AND PERCEPTION

2. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PRINCIPLES OF SENSATION Sensation – process of sensing our environment through:  touch  taste  sight  sound  smell

3. Copyright © 2016 Pearson Education, Inc. All Rights Reserved SENSORY SYSTEM BASICS Steps in sensory coding: 1.Specialized cells called sensory receptors transform physical energy into nerve impulses 2.Specialized brain regions process incoming sensory information

4. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.1 SENSORY CODING

5. Copyright © 2016 Pearson Education, Inc. All Rights Reserved SENSORY LIMITS Sensory adaptation – gradual decline in sensitivity to a constant stimulus  Occurs when sensory receptors receive the same input over & over again

6. Copyright © 2016 Pearson Education, Inc. All Rights Reserved RELATIONSHIPS AMONG THE SENSORY SYSTEMS Bottom-up processing – small bits of information received by the sensory receptors work their way up through more complex centers of the brain for recognition & interpretation Top-down processing – concepts or set of expectations from past experience influences information taken in through the senses

7. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.3 SENSORY AREAS OF THE BRAIN

8. HOW WE SEE VISUAL PROCESSING

9. Copyright © 2016 Pearson Education, Inc. All Rights Reserved WAVELENGTHS OF LIGHT (1 OF 3) Eyes respond to pulses of energy in the form of wavelengths of light Visible spectrum – the narrow band of the electromagnetic spectrum visible to the human eye

10. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.6 THE VISUAL SPECTRUM

11. Copyright © 2016 Pearson Education, Inc. All Rights Reserved WAVELENGTHS OF LIGHT (2 OF 3) Physical properties of wavelengths of light: 1.Frequency – the distance between the wavelengths  provides information about hue or color 2.Amplitude – the height of the wavelength  provides information about the intensity of a color

12. Copyright © 2016 Pearson Education, Inc. All Rights Reserved WAVELENGTHS OF LIGHT (3 OF 3) Physical properties of wavelengths of light: 3.Saturation – the number of wavelengths making up the light  gives information about the purity or richness of a color

13. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EYE (1 OF 4) Light enters the eye and travels from the surface to the back of the eye Key structures:  cornea – clear protective covering that helps direct light as it enters the eye  iris – colored part of the eye that contains the muscle that controls the size of the pupil

14. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EYE (2 OF 4)  pupil – dark hole in the center of the eye that allows light to enter  lens – structure that focuses light onto the back surface of the eye  retina – inner lining of the eye that contains receptors for vision

15. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.7 THE STRUCTURE OF THE EYE

16. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EYE (3 OF 4) Photoreceptors – tiny cells in the retina sensitive to light Two types: 1.Rods – located along the edges of the retina and help to detect movement  active in low-light conditions 2.Cones – sensitive to the wavelengths of light that give rise to the color of an object and help to see fine detail  active in bright lighting conditions

17. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.8 RODS AND CONES

18. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EYE (4 OF 4) Optic nerve – carries neural impulses from the retina to the visual cortex in the back of the brain for interpretation Optic chiasm – junction where information from the eyes crosses from one side of the brain to the other

19. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.10 VISUAL PATHWAYS INTO THE BRAIN

20. Copyright © 2016 Pearson Education, Inc. All Rights Reserved THEORIES OF COLOR VISION Trichromatic theory = human eye has three types of receptors with differing sensitivities to different light wavelengths associated with red, green, and blue. Opponent process theory = color perception depends on receptors that make antagonistic responses to red versus green, blue versus yellow, and black versus white. Dual-process theory – both theories work in concert to allow color vision

21. Copyright © 2016 Pearson Education, Inc. All Rights Reserved COLOR THEORIES EXPLAINED

22. HOW WE HEAR

23. Copyright © 2016 Pearson Education, Inc. All Rights Reserved HEARING (1 OF 2) Physical properties of sound waves: 1.Frequency – number of waves that occur within one second  measured in hertz (Hz)  determines pitch 2.Amplitude – height/strength of the wavelength  taller wavelengths experienced as louder  measured in terms of decibels

24. Copyright © 2016 Pearson Education, Inc. All Rights Reserved HEARING (2 OF 2) 3. Saturation – number & complexity of the waves occurring at same time  determines purity and quality of a sound

25. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EAR (1 OF 2) Pinna – outer ear which funnels sound into the ear canal Eardrum (tympanic membrane) – thin plane of tissue that vibrates when hit by sound waves Ossicles – three tiny bones (ossicles) that make up the middle ear and transfer vibrations to the inner ear

26. Copyright © 2016 Pearson Education, Inc. All Rights Reserved STRUCTURE OF THE EAR (2 OF 2) Inner ear is comprised of:  Cochlea – coiled tube lined with the basilar membrane  fluid-filled membrane that contains thousands of hair-like cells  sound vibrations cause hair cells to bend & release neurotransmitters that convert sound waves into nerve impulses  Auditory nerve – clusters of hair cells that transport the auditory information to the brain for processing

27. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.13 THE STRUCTURE OF THE EAR

28. Copyright © 2016 Pearson Education, Inc. All Rights Reserved HEARING LOSS Types:  Conductive hearing loss – damage to the eardrums or ossicles prevents vibrations from reaching the cochlea  Sensorineural hearing loss – damage to the middle or inner ear or the hair cells in the cochlea

29. Copyright © 2016 Pearson Education, Inc. All Rights Reserved HOW WE SMELL Olfaction – chemical sense of smell resulting from chemicals reaching the nose Olfactory receptor cells – cells that line the nasal cavity and respond to molecules in the air  work like a lock and key Olfactory nerve – sends neural signals from the olfactory receptors to the brain

30. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.15 OLFACTORY PROCESS

31. Copyright © 2016 Pearson Education, Inc. All Rights Reserved TASTE Gustation – chemical sense of taste resulting from chemicals reaching the tongue Papillae – bumps on the tongue that contain clumps of taste buds made up of taste receptor cells  five types: salty, sour, sweet, bitter, and savory

32. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.16 PARTS OF THE TONGUE

33. Copyright © 2016 Pearson Education, Inc. All Rights Reserved SKIN AND BODY SENSES (1 OF 3) 1.Kinesthetic sense – tracks the position and orientation of the body parts  proprioceptors – receptors in the muscles, tendons, and joints that detect orientation of the body and send impulses to the brain

34. Copyright © 2016 Pearson Education, Inc. All Rights Reserved SKIN AND BODY SENSES (2 OF 3) 2.Vestibular sense – sense of balance  receptors located in the inner ear & inside and outside the semicircular canals  canals filled with fluid that sloshes around when the head moves, causing the tiny hair cells to bend  bending cells send nerve impulses to the brain and provide information about the location of the head

35. Copyright © 2016 Pearson Education, Inc. All Rights Reserved SKIN AND BODY SENSES (3 OF 3) 3.Touch – specialized receptors contained in the skin allow for the sensations of pressure, pain, heat, and cold  excessive amounts of stimulation of pressure and temperature receptors result in pain

36. Copyright © 2016 Pearson Education, Inc. All Rights Reserved THE PHYSIOLOGY OF PAIN (1 OF 3)  Gate-Control Theory – spinal cord contains neurological “gates” that open when body tissue is damaged  pain signals travel up the spinal cord to the brain  Pain sensation triggered by release of neurotransmitter called substance P

37. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.18 GATE CONTROL THEORY

38. Copyright © 2016 Pearson Education, Inc. All Rights Reserved THE PHYSIOLOGY OF PAIN (2 OF 3) Analgesics or acupuncture reduce pain by blocking release of substance P and/or closing down sensory gates in the spinal cord. Chronic Pain tends to require more alternative therapies, like biofeedback or meditation, to reduce the potential liver damage caused by long term analgesic use.

39. Copyright © 2016 Pearson Education, Inc. All Rights Reserved THE PHYSIOLOGY OF PAIN (3 OF 3) Studies have found that the more someone expects something to hurt, the more neurological pain activity they will have, and will hurt more.

40. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.17 THE EXPERIENCE OF PAIN

41. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PERCEPTION Perception – how the brain makes meaning out of sensory information Perceptual set—a readiness to perceive a stimulus in a particular way based on our previous experiences.  creates a certain slant in how you interpret sensory input.

42. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PERCEPTUAL CONSTANCIES Perceptual constancies  Size constancy – object stays the same size regardless of the distance  Shape constancy – shapes stay the same regardless of their orientation  Brightness constancy – brightness stays the same regardless of the lighting

43. Copyright © 2016 Pearson Education, Inc. All Rights Reserved GESTALT PRINCIPLES (1 OF 2) Gestalt psychology basic assumption “ that the whole can be greater than the sum of its parts”. Gestalt psychologists formulated series of principles that describe how visual system organizes a scene into discrete forms. Figure-ground – tendency to see figures against a background

44. Copyright © 2016 Pearson Education, Inc. All Rights Reserved GESTALT PRINCIPLES (2 OF 2) Nearness – tendency to group together objects close together in space or time Similarity – tendency to group together objects similar to each other Closure – tendency to close in the gaps of an object and see a whole object Continuity – tendency to see one continuous, flowing movement, rather than broken up parts

45. Copyright © 2016 Pearson Education, Inc. All Rights Reserved DEPTH PERCEPTION Depth perception – interpretation of visual cues that indicate how near or far away objects are.

46. Copyright © 2016 Pearson Education, Inc. All Rights Reserved MONOCULAR CUES (1 OF 2) Monocular cues – require the use of each eye separately  Relative size – size of an object tells about distance  Overlap – objects partially blocking other objects assumed closer  Texture – objects closer up have more texture

47. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (1 OF 3) MONOCULAR DEPTH CUES: RELATIVE SIZE

48. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (2 OF 3) MONOCULAR DEPTH CUES: OVERLAP

49. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (3 OF 3) MONOCULAR DEPTH CUES: TEXTURE

50. Copyright © 2016 Pearson Education, Inc. All Rights Reserved MONOCULAR CUES (2 OF 2)  Linear perspective – parallel lines appear to get closer in the distance  Light and shadow – brighter objects perceived as being closer than darker objects  Aerial perspective – objects that appear hazy perceived as farther away  Relative motion – closer objects appear to move more quickly than distant objects

51. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (1 OF 3) MONOCULAR DEPTH CUES: LINEAR PERSPECTIVE

52. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (2 OF 3) MONOCULAR DEPTH CUES: LIGHT AND SHADOW

53. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 (3 OF 3) MONOCULAR DEPTH CUES: AERIAL PERSPECTIVE

54. Copyright © 2016 Pearson Education, Inc. All Rights Reserved FIGURE 3.22 MONOCULAR DEPTH CUES: RELATIVE MOTION

55. Copyright © 2016 Pearson Education, Inc. All Rights Reserved BINOCULAR CUES Binocular Cues – uses information from both eyes for interpretation of visual cues that indicate how near or far away objects are. Convergence – rotation of the eyes inward as object gets closer  brain infers distance of an object by the amount of tension in the eye muscles Stereopsis – combining and comparing the slightly different images from each eye  differing view between the eyes called retinal disparity

56. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PERCEPTUAL LEARNING (1 OF 3) Perceptual learning – long-lasting changes to the brain’s perceptual systems that improve the ability to respond to the environment  Most dramatic changes in perception occur within first 6 years of life Perceptual expertise – repeated experiences with an object strengthen the connections between the perceptual centers in the brain

57. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PERCEPTUAL LEARNING (2 OF 3) Predictive coding – brain anticipates incoming sensory information by creating a template with which to compare it

58. Copyright © 2016 Pearson Education, Inc. All Rights Reserved PERCEPTUAL LEARNING (3 OF 3) Influenced by two groups of factors:  External factors – social information, situational, and contextual cues  Internal factors – internal organization of categories influence how perceptually available they are  also influenced by motivation and emotion

59. Copyright © 2016 Pearson Education, Inc. All Rights Reserved OPTICAL ILLUSIONS Optical illusions – visual experiences that don’t conform to reality Two categories: 1.Physiological illusions – result of an unusual or excessive stimulation of brightness, color, movement, or contrast  involves the mechanics of the eye 2.Cognitive illusions – occur when natural visual assumptions get misinterpreted  brain misinterprets information about the relative size, perspective, or contours of an object

60. Copyright © 2016 Pearson Education, Inc. All Rights Reserved CULTURE AND COGNITION Asian & Eastern Cultures tend to see:  Holistic cues – focus on the entire shape of the object Western Cultures tend to see:  Part cues – attune to the smaller pieces of the object