1. SENSATION AND PERCEPTION

2. 2 OUR SENSORY AND PERCEPTUAL PROCESSES WORK TOGETHER TO HELP US SORT OUT COMPLEX IMAGES. MAKING SENSE OF COMPLEXITY “The Forest Has Eyes,” Bev Doolittle

3. 3 SENSATION & PERCEPTION HOW DO WE CONSTRUCT OUR REPRESENTATIONS OF THE EXTERNAL WORLD? TO REPRESENT THE WORLD, WE MUST DETECT PHYSICAL ENERGY (A STIMULUS) FROM THE ENVIRONMENT AND CONVERT IT INTO NEURAL SIGNALS. THIS IS A PROCESS CALLED SENSATION. WHEN WE SELECT, ORGANIZE, AND INTERPRET OUR SENSATIONS, THE PROCESS IS CALLED PERCEPTION.

4. 4 SENSING THE WORLD SENSES ARE NATURE’S GIFT THAT SUIT AN ORGANISM’S NEEDS. A FROG FEEDS ON FLYING INSECTS; A MALE SILKWORM MOTH IS SENSITIVE TO FEMALE SEX- ATTRACTANT ODOR; AND WE AS HUMAN BEINGS ARE SENSITIVE TO SOUND FREQUENCIES THAT REPRESENT THE RANGE OF HUMAN VOICE.

5. SENSATION: RECEIVING MESSAGES ABOUT THE WORLD SENSE ORGANS SEE, HEAR, TASTE, SMELL, TOUCH, BALANCE, AND EXPERIENCE THE WORLD SENSORY RECEPTOR CELLS TRANSMIT SENSATION PERCEPTION – INTERPRETING INFORMATION AND FORMING IMAGES STIMULUS Sensation and Perception

6. TRANSDUCTION IN SENSATION, THE TRANSFORMATION OF STIMULUS ENERGY (SIGHTS, SOUNDS, SMELLS) INTO NEURAL IMPULSES. INFORMATION GOES FROM THE SENSES TO THE THALAMUS, THEN TO THE VARIOUS AREAS IN THE BRAIN. Remember Ethan in Sky High. He changes his body to slime. Solid form to liquid form. Change from one form of energy to another. Click the picture to watch power placement.

7. SENSORY LIMITS: HOW STRONG MUST MESSAGES BE? THRESHOLD – LOWER LIMITS ABSOLUTE THRESHOLD – SMALLEST TO BE DETECTED DIFFERENCE THRESHOLD – SMALLEST DIFFERENCE BETWEEN 2 STIMULI TO BE DETECTED 50% OF TIME Sensation and Perception Proportion of “Yes” Responses 0.00 0.50 1.00 0 5 10 15 20 25 Stimulus Intensity (lumens)

8. SENSORY THRESHOLDS Vision A candle flame seen at 30 mi. on a clear, dark night Hearing The tick of a watch under quiet conditions at 20 ft. Taste One teaspoon of sugar in 2 gallons of water Smell 1 drop of perfume diffused into the entire volume of a 3 room apartment Touch The wing of a bee falling on your cheek from a height of 1 cm

9. 9 PSYCHOPHYSICS A STUDY OF THE RELATIONSHIP BETWEEN PHYSICAL CHARACTERISTICS OF STIMULI AND OUR PSYCHOLOGICAL EXPERIENCE WITH THEM. Physical World Psychological World LightBrightness SoundVolume PressureWeight SugarSweet

10. 10 WEBER’S LAW TWO STIMULI MUST DIFFER BY A CONSTANT MINIMUM PERCENTAGE (RATHER THAN A CONSTANT AMOUNT), TO BE PERCEIVED AS DIFFERENT. WEBER FRACTION: K =  I/I. StimulusConstant (k) Light8% Weight2% Tone3%

11. 11 SENSORY ADAPTATION DIMINISHED SENSITIVITY AS A CONSEQUENCE OF CONSTANT STIMULATION. Put a band aid on your arm and after awhile you don’t sense it. Do you feel your underwear all day?

12. VISIONVISION OUR MOST DOMINATING SENSE. VISUAL CAPTURE

13. 13 NOW YOU SEE, NOW YOU DON’T

14. 14 Visible Spectrum THE STIMULUS INPUT: LIGHT ENERGY Both Photos: Thomas Eisner

15. 15 PHYSICAL CHARACTERISTICS OF LIGHT 1.WAVELENGTH (HUE/COLOR) THE MORE WAVELENGTHS IN LIGHT, THE LESS SATURATED OR PURE ITS HUE IS 2.INTENSITY (BRIGHTNESS)

16. VISION- PHYSICAL PROPERTIES OF WAVES Short wavelength=high frequency (bluish colors, high-pitched sounds) Long wavelength=low frequency (reddish colors, low-pitched sounds) Great amplitude (bright colors, loud sounds) Small amplitude (dull colors, soft sounds)

17. 17 WAVELENGTH (HUE) Different wavelengths of light result in different colors. 400 nm 700 nm Long wavelengths Short wavelengths Violet IndigoBlue Green Yellow OrangeRed

18. 18 INTENSITY (BRIGHTNESS) INTENSITY: AMOUNT OF ENERGY IN A WAVE DETERMINED BY THE AMPLITUDE. IT IS RELATED TO PERCEIVED BRIGHTNESS.

19. 19 INTENSITY (BRIGHTNESS) Blue color with varying levels of intensity. As intensity increases or decreases, blue color looks more “washed out” or “darkened.”

20. 20 THE EYE

21. 21 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. 5.PUPIL- ADJUSTABLE OPENING IN THE CENTER OF THE EYE

22. 22 THE LENS LENS: TRANSPARENT STRUCTURE BEHIND THE PUPIL THAT CHANGES SHAPE TO FOCUS IMAGES ON THE RETINA. ACCOMMODATION: THE PROCESS BY WHICH THE EYE’S LENS CHANGES SHAPE TO HELP FOCUS NEAR OR FAR OBJECTS ON THE RETINA.

23. THE EYE: HOW DOES IT WORK? LIGHT PASSES THROUGH CORNEA IRIS REGULATES LIGHT THROUGH PUPIL INTO LENS LENS HELD IN PLACE BY CILIARY MUSCLE RETINA HAS RODS AND CONES FOR RECEPTORS Sensation and Perception

24. 24 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. Fovea: Central point in the retina around which the eye’s cones cluster.

25. PHOTORECEPTORS Cones Rods

26. 26 PHOTORECEPTORS E.R. Lewis, Y.Y. Zeevi, F.S Werblin, 1969

27. THE EYE RODS NOT LOCATED IN FOVEA RESPONSIBLE FOR PERIPHERAL VISION HUNDREDS OF TIMES MORE SENSITIVE TO LIGHT THAN CONES PRODUCE IMAGES PERCEIVED WITH LESS VISUAL ACUITY THAN CONES DO NOT DETECT COLOR CONES GIVE BRAIN MORE PRECISE INFORMATION CODE INFORMATION ABOUT COLOR RESPOND ONLY IN BRIGHT LIGHT Sensation and Perception

28. 28 BIPOLAR & GANGLION CELLS Bipolar cells receive messages from photoreceptors and transmit them to ganglion cells, which converge to form the optic nerve.

29. 29 VISUAL INFORMATION PROCESSING Optic nerves connect to the thalamus in the middle of the brain, and the thalamus connects to the visual cortex.

30. 30 SHAPE DETECTION Specific combinations of temporal lobe activity occur as people look at shoes, faces, chairs and houses. Ishai, Ungerleider, Martin and Haxby/ NIMH

31. DARK AND LIGHT ADAPTATION DARK ADAPTATION RECEPTORS RECEIVE NEW SUPPLY OF CHEMICALS AFTER 30 MINUTES IN THE DARK - LEVEL OF SENSITIVITY ABOUT 100,000 TIMES GREATER THAN IN BRIGHT LIGHT LIGHT ADAPTATION RODS AND CONES HIGHLY RESPONSIVE – OVERLOAD BLEACHING OUT OF RECEPTOR CHEMICALS OCCURS NIGHT BLINDNESS – VITAMIN A DEFICIENCY Sensation and Perception

32. VISUAL INFORMATION PROCESSING  TRICHROMATIC (THREE COLOR) THEORY  YOUNG AND HELMHOLTZ  THREE DIFFERENT RETINAL COLOR RECEPTORS  RED  GREEN  BLUE

33. COLOR VISION COLOR AFTERIMAGES COMPLEMENTARY COLORS – YELLOW AND BLUE, RED AND GREEN PROLONGED STARING CAUSES GHOSTLY AFTERIMAGE IN COMPLEMENTARY COLORS OCCURS IN ALL FOR COMPLEMENTARY COLORS Sensation and Perception

34. 34 COLOR BLINDNESS Ishihara Test GENETIC DISORDER IN WHICH PEOPLE ARE BLIND TO GREEN OR RED COLORS. THIS SUPPORTS THE TRICHROMATIC THEORY.

35. COLOR BLINDNESS AFFECTS ABOUT 8% OF MALES, 1% OF FEMALES PARTIAL COLOR BLINDNESS – DIFFICULTY DISTINGUISHING BETWEEN TWO COLORS RED-GREEN BLINDNESS DUE TO GENETIC DEFECT YELLOW-BLUE BLINDNESS DUE TO ABSENCE OF BLUE PIGMENT IN CONES Sensation and Perception

36. VISUAL INFORMATION PROCESSING OPPONENT-PROCESS THEORY- OPPOSING RETINAL PROCESSES ENABLE COLOR VISION “ON”“OFF” RED GREEN GREEN RED BLUE YELLOW YELLOW BLUE BLACK WHITE WHITE BLACK

37. 37 OPPONENT COLORS 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.

38. HEARING Our auditory sense

39. 39 HEARING THE STIMULUS INPUT: SOUND WAVES SOUND WAVES ARE COMPRESSING AND EXPANDING AIR MOLECULES.

40. HEARING: SENSING SOUND WAVES AUDITION - DETECTION OF SOUND WAVES FREQUENCY OF CYCLES COMPRESSION – INCREASED DENSITY OF WAVES RAREFACTION – REDUCED DENSITY OF WAVES DETERMINES PITCH OF SOUND INTENSITY MEASURED IN DECIBEL (DB) UNITS PROLONGED EXPOSURE TO OVER 85 DB CAUSES HEARING LOSS TIMBRE – QUALITY OF SOUND Sensation and Perception

41. Maximum level of industrial noise considered safe Characteristics of Sound Waves 204060801001600120180140 Loud thunder or rock concert Pain Threshold City bus Normal conversation Subway db Noisy automobile Absolute threshold of human hearing Quiet office Whisper Rocket launch Prolonged exposure above 85 decibels produces hearing loss.

43. THE EAR: HOW DOES IT WORK? OUTER EAR PINNA – EXTERNAL PART OF EAR THAT COLLECTS SOUND EXTERNAL AUDITORY CANAL – CONNECTS OUTER AND MIDDLE EAR MIDDLE EAR CARDUM – TYMPANIC MEMBRANE; 1ST STRUCTURE EARDRUM - OUTERMOST STRUCTURE OF MIDDLE EAR PASSES VIBRATION TO INTERCONNECTED BONES (HAMMER, ANVIL, AND STIRRUP) Sensation and Perception

44. 44 THE EAR Dr. Fred Hossler/ Visuals Unlimited

45. THE EAR: HOW DOES IT WORK? INNER EAR OVAL WINDOW – EARDRUMLIKE STRUCTURE AT END OF COCHLEA ROUND WINDOW – EARDRUMLIKE STRUCTURE AT OTHER END OF COCHLEA BASILAR MEMBRANE – FORMS FLOOR FOR EAR’S SENSORY RECEPTORS ORGAN OF CORTI – CONTAINS HAIRLIKE RECEPTOR CELLS Sensation and Perception

46. © 2007 The McGraw-Hill Companies, Inc. All Rights Reserved Slide 46 THE EAR

47. TRANSDUCTION IN THE EAR SOUND WAVES HIT THE EARDRUM THEN ANVIL THEN HAMMER THEN STIRRUP THEN OVAL WINDOW. EVERYTHING IS JUST VIBRATING. THEN THE COCHLEA VIBRATES. THE COCHLEA IS LINED WITH MUCUS CALLED BASILAR MEMBRANE. IN BASILAR MEMBRANE THERE ARE HAIR CELLS. WHEN HAIR CELLS VIBRATE THEY TURN VIBRATIONS INTO NEURAL IMPULSES WHICH ARE CALLED ORGAN OF CORTI. SENT THEN TO THALAMUS UP AUDITORY NERVE. It is all about the vibrations!!!

48. WE HEAR SOUND WAVES THE HEIGHT OF THE WAVE GIVES US THE AMPLITUDE OF THE SOUND. THE FREQUENCY OF THE WAVE GIVES US THE PITCH IF THE SOUND.

49. AUDITION  CONDUCTION HEARING LOSS  HEARING LOSS CAUSED BY DAMAGE TO THE MECHANICAL SYSTEM THAT CONDUCTS SOUND WAVES TO THE COCHLEA  NERVE HEARING LOSS  HEARING LOSS CAUSED BY DAMAGE TO THE COCHLEA’S RECEPTOR CELLS OR TO THE AUDITORY NERVE

50. 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.

51. 51 LOCALIZATION OF SOUNDS BECAUSE WE HAVE TWO EARS, SOUNDS THAT REACH ONE EAR FASTER THAN THE OTHER EAR CAUSE US TO LOCALIZE THE SOUND.

52. 52 LOCALIZATION OF SOUND 1. INTENSITY DIFFERENCES 2. TIME DIFFERENCES TIME DIFFERENCES AS SMALL AS 1/100,000 OF A SECOND CAN CAUSE US TO LOCALIZE SOUND. THE HEAD ACTS AS A “SHADOW” OR PARTIAL SOUND BARRIER.