Sense Organs

2. Sense Organs The first step in knowing

3. Sound • Sound waves travel through air • Vibration changes air pressure • called sound waves

4. Sound • Every sound has pitch and loudness • Depends on frequency (cycle per second) • Low sounds = low frequency • High sounds = high frequency • Examples • Woman’s voice=shorter vocal chords ; Man’s voice =longer vocal chords • Violin has shorter strings than a cello

5. Sound • Determined by height (amplitude of waves) • Higher the amplitude the louder the sound • Amplitude is measured in decibels • Zero dB = absolute threshold for hearing • Ticking watch 20ft away • 90 db beginnings of hearing loss can occur • Train whistle, lawn mower

6. Parts of the Ear • Outer ear • pinna (outside of the skull) • Middle ear • ear drum & bones (hammer, anvil, stirrup) • Inner ear • cochlea (snail shape tube that contains fluid & neurons) • Moves in response to vibrations • Movement transmits neural impulses along auditory nerve to the brain

8. Hearing & deafness • Sensorineural deafness • Damage to inner ear • Loss of neurons in cochlea • Result of disease or prolonged exposure to loud sounds • Conductive deafness • Damage to middle ear • Use hearing aid to increase amplitude

9. Smell & Taste • Odors are detected by receptor neurons in each nostril • Info is sent via the olfactory nerve • Taste has 4 qualities • Sweet, sour, salty, bitter (umami=savory) • Apples & onions taste similar, it is their odor that makes their flavors different • Taste buds –receptor neurons • Taste sensitivities can be inherited • Few people ever lose their sense of taste • You grow new taste buds throughout your life

10. Skin & Touch • Skin senses are a combination of pressure, temperature & pain • Reduces stress & depression • Can help babies thrive • Extremities and face more sensitive than thighs, calves, upper arms and shoulders • Different receptors fire for cold & hot • The more pain receptors in our skin, the more sensitive the area

11. How do pain messages travel? • Pain in contact area ->spinal chord ->thalamus ->projected on to cerebral cortex -> brain registers sensitivity & location -> prostaglandins produce & transmit pain messages to the brain • Ibuprofin & aspirin stop production of prostaglandins

12. Why we do or do not feel pain • Gate Theory: rubbing or scratching sends competing messages with pain messages • Prevents some of the pain messages from getting through • Phantom pain: people who lose a limb have memories of pain activated by nerve endings near location of original injury

13. Perception

14. Rules of Perceptional Organization • Closure • tendency to perceive a whole figure even when there are gaps. 2. Figure- Ground Perception • The perception of figures against a background • What we perceive as figure and what we perceive as background influence perception

15. Figure Ground Illusion

19. Toblerone Chocolate

20. Rules of Perceptional Organization 3. Selective Attention • the idea that we are only aware of a small percentage of what we experience. • The Door Study

21. Rules of Perceptional Organization 3. Selective Attention • the idea that we are only aware of a small percentage of what we experience.

22. Rules of Perceptional Organization 3. Selective Attention • the idea that we are only aware of a small percentage of what we experience. • The Door Study

23. Rules of Perceptional Organization 4. Proximity • Tendency to group nearby figures together

24. Rules of Perceptional Organization 5. Similarity • People think of similar objects as belonging together

25. Rules of Perceptional Organization 6. Continuity • Group stimuli into continuous patterns

26. Perception of Movement/ Stroboscopic Movement • To sense movement, an object must change position relative to other objects Stroboscopic Movement • Illusions of movement • produced by showing rapid progression of images or objects that arent moving at all • Flip books

27. Depth Perception • Perceived through monocular and binocular cues • Monocular Cues: • need only one eye to perceive • Cause certain objects to appear more distant from the viewer than others

28. Depth Perception 2. Binocular Cues: • Need both eyes • Retinal disparity: depth based on difference between 2 images of object that retina receives as it moves closer or farther away • Convergence: causes feelings of tension in eye muscle.

32. The Ames Room • Observe this room. Take special note of the size, shape, color and details of the room. • Can one girl really be that much bigger than the other?

33. The Ames Room Viewer assumes room is rectangular and the image cast onto the retina is consistent with this hypothesis • Naïve viewers conclude that one girl is larger, when in fact she is just closer • Further Reading:http://psylux.psych.tu-dresden.de/i1/kaw/diverses%20Material/www.illusionworks.com/html/ames_room.html

34. Optical Illusions • The perceptual hypotheses that we create become especially striking when they are wrong • Proximity, Depth Cues, Similarity, and Figure Ground perception affect the hypotheses that we make • Human perceptions are HIGHLY SUBJECTIVE

35. Illusion #9A face? A word?

36. Illusion #10(4) Which word do you see first?

37. Illusion #11Stare at the center for 15 sec and then look up – what do you see?

38. Illusion #11Stare at the center for 15 sec and then look up – what do you see?

39. Illusion #13How many black dots are there?

40. Illusion #16Mind Warp

41. Illusion #18Impossible Figures (3) • objects that can be represented in two-dimensional pictures but cannot exist in three-dimensional space

45. Playing with Words Perception of letters, words and phrases

46. Illusion #19Read the following out-loud – now read it again slowly and see if you fell for the trick

47. Illusion #20

48. Illusion #21What do you think? • Aoccdrnig to a rscheearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae we do not raed ervey lteter by it slef but the wrod as a wlohe.

49. Illusion #22The Stroop EffectTime yourself saying the word – then time yourself saying the color of the ink. What is the difference?

50. The Stroop Effect • The words themselves have a strong effect over your ability to say the color • There is an interference in the information your brain receives - and this causes a problem • Speed of Processing Theory • Words read faster that colors are named • Selective Attention Theory • Naming colors requires more attention than reading the word • For Further Reading: http://www.snre.umich.edu/eplab/demos/st0/stroopdesc.html