1. Ch 4 Sensation & Perception Sensation: your window to the world Perception: interpreting what comes in your window.

2. 2 Sensation & Perception Sensation The stimulation of sensory receptors (senses) and the transmission of sensory information to the brain Perception Psychological process of how we interpret sensory stimulation

3. 3 “The Forest Has Eyes,” Bev Doolittle

4. 4 Absolute Threshold: the weakest amount of stimulus that can be detected

5. 5 Difference Threshold Difference Threshold: Minimum amount of difference that can be detected between two stimuli, also called just noticeable difference (JND).

6. 6 Signal Detection Theory (SDT) A method of distinguishing sensory stimuli Carol Lee/ Tony Stone Images The following effect Signal detection: Setting Physical state Mood Attitudes

7. Sensory Adaptation Decreased responsiveness to stimuli due to constant stimulation. Do you feel your underwear all day?

8. Energy v. Chemical senses Energy SensesChemical Senses

9. VisionVision Our most dominating sense. Visual Capture –Video

10. 10 Visible Spectrum Light Energy Both Photos: Thomas Eisner

11. 11 The Eye

12. 12 Parts of the eye 1.Cornea: Transparent tissue where light enters the eye. 2.Iris: Muscle that expands and contracts to change the size of the opening (pupil) for light. 3.Lens: Focuses the light rays on the retina. 4.Retina: Contains sensory receptors that process visual information and sends it to the brain.

13. 13 Retina

14. 14 Visual Information Processing Optic nerves connect to the thalamus in the middle of the brain, and the thalamus connects to the visual cortex.

15. 15 Optic Nerve, Blind Spot & Fovea http://www.bergen.org Optic nerve: Carries neural impulses from the eye to the brain. Blind Spot: Point where the optic nerve leaves the eye because there are no receptor cells located there. This creates a blind spot. Fovea: Central point in the retina around which the eye’s cones cluster.

16. 16 Test your Blind Spot Use your textbook. Close your left eye, and fixate your right eye on the black dot. Move the page towards your eye and away from your eye. At some point the car on the right will disappear due to a blind spot.

17. 17 Photoreceptors E.R. Lewis, Y.Y. Zeevi, F.S Werblin, 1969

18. How we see color in the eye Rods (receptors) –Allow us to see in black in white Cones (receptors) –Allow us to see in color 18

19. Visual Acuity 19

20. 20 The Lens Nearsightedness: A condition in which nearby objects are seen more clearly than distant objects. Farsightedness: A condition in which faraway objects are seen more clearly than near objects.

21. Vision : In the Brain Feature Detectors We have specific cells that see the lines, motion, curves and other features of this turkey. These cells are called feature detectors.

22. 22 Parallel Processing Processing of several aspects of the stimulus simultaneously is called parallel processing. The brain divides a visual scene into subdivisions such as color, depth, form and movement etc.

23. Color Vision

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25. 25 Photoreceptors - Cones Red Cones Green Cones Blue Cones

26. 26 Color Blindness Ishihara Test Genetic disorder in which people are blind to green or red colors.

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28. 28 Gaze at the middle of the flag for about 30 Seconds. When it disappears, stare at the dot and report whether or not you see Britain's flag.

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33. Hearing Our auditory sense

34. 34 Frequency (Pitch) Frequency (pitch): The dimension of frequency determined by the wavelength of sound. Wavelength: The distance from the peak of one wave to the peak of the next.

35. 35 Intensity (Loudness) Intensity (Loudness): Amount of energy in a wave, determined by the amplitude, relates to the perceived loudness.

36. 36 Quality (Timbre) Quality (Timbre): Characteristics of sound from a zither and a guitar allows the ear to distinguish between the two. http://www.1christian.net www.jamesjonesinstruments.com Zither Guitar

37. 37 Loudness of Sound 70dB 120dB Richard Kaylin/ Stone/ Getty Images

38. The Ear

39. 39 The Ear Dr. Fred Hossler/ Visuals Unlimited

40. 40 The Ear Outer Ear: Pinna. Collects sounds. Middle Ear: Chamber between eardrum and cochlea containing three tiny bones (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window. Inner Ear: Innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

41. 41 Localization of Sounds Because we have two ears, sounds that reach one ear faster than the other ear cause us to localize the sound.

42. 42 Hearing Loss Conduction Hearing Loss: Hearing loss caused by damage to the middle ear Sensorineural Hearing Loss: Hearing loss caused by damage to the cochlea’s and inner ear. Also called nerve deafness.

43. Deafness Conduction Deafness Something goes wrong with the sound and the vibration on the way to the cochlea. You can replace the bones or get a hearing aid to help. Nerve (sensorineural) Deafness The hair cells in the cochlea get damaged. Loud noises can cause this type of deafness. NO WAY to replace the hairs. Cochlea implant is possible.

44. 44 Deaf Culture Cochlear implants are electronic devices that enable the brain to hear sounds. Cochlear ImplantDeaf Musician EG Images/ J.S. Wilson © Wolfgang Gstottner. (2004) American Scientist, Vol. 92, Number 5. (p. 437)

45. 45 Smell Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste, there are many different forms of smell.

46. 46 Smell and Memories The brain region for smell (in red) is closely connected with the brain regions involved with memory (limbic system). That is why strong memories are made through the sense of smell.

47. 47 Taste Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors for a fifth taste have been discovered called “Umami”. Sweet Sour Salty BitterUmami (Savory)

48. Taste We have bumps on our tongue called papillae. Taste buds are located on the papillae (they are actually all over the mouth). Sweet, salty, sour and bitter.

49. 49 Sensory Interaction When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its texture on the tongue to produce flavor. Taste Lab

50. The Skin Sense: Touch Receptors located in our skin. Pain, Pressure, Warmth & Cold

51. 51 Pain Pain tells the body that something has gone wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in which the afflicted person feels no pain. Ashley Blocker (right) feels neither pain nor extreme hot or cold. AP Photo/ Stephen Morton

52. 52 Body Position and Movement The sense of our body parts’ position and movement is called kinesthesis. The vestibular sense monitors the head (and body’s) position. http://www.heyokamagazine.com Whirling Dervishes Wire Walk Bob Daemmrich/ The Image Works

53. Kinesthetic Sense Tells us where our body parts are. Receptors located in our muscles and joints. Without the kinesthetic sense you could touch the button to make copies of your buttocks.

54. Vestibular Sense Tells us where our body is oriented in space. Our sense of balance. Located in our semicircular canals in our ears. LAB