2. How Do We Study Sensation? Psychophysics: The study of the relationship between physical stimuli and the perception of them. Psychophysics also studies the physical characteristics of stimuli such as amp and loudness of sound. Psychophysics: The study of the relationship between physical stimuli and the perception of them. Psychophysics also studies the physical characteristics of stimuli such as amp and loudness of sound. Gustav Fechner Father of Psychophysics (and a lot of fun at parties) Gustav Fechner Father of Psychophysics (and a lot of fun at parties) Prepared by Dr. Gordon Vessels 2004

3. Sensation & Perception Sensation - the process of transducing physical energy from the environment into electrical energy in neurons. Sensory Receptors Transduction Perception – the selection, organization, & interpretation of input from sensory organs that takes place in the cerebral cortex. Prepared by Dr. Gordon Vessels 2004

4. Violet360nm Indigo Blue Green500nmYellow Orange600nm Red700nm Violet360nm Indigo Blue Green500nmYellow Orange600nm Red700nm Electromagnetic Spectrum Electromagnetic Spectrum Transduction - the process of converting stimulus energy to neural energy Prepared by Dr. Gordon Vessels 2004

5. CORNEA LENS IRIS SCLERA CHOROID RETINA CILIARY MUSCLE OPTIC NERVE Picture modeled after one used by Hiohde at http://phys2.med.osaka-u.ac.jp/~hiohde/gannka/eyeball.html hiohde@phys2.med.osaka-u.ac.jp

6. Macula Optic Nerve Ciliary Muscle (controls the Lens) Retina(Rods and Cones Eye Muscle Iris Sclera (white of the eye) Lens Cornea Pupil Fovea (point of central focus Blind Spot Eye Muscle Arranged Dr. Gordon Vessels 2004

7. Longer Wavelength Lower Frequency Shorter Wavelength Higher Frequency Properties of Created by Dr. Gordon Vessels 2004

8. Properties of Light Smaller Amplitude Dull Colors Smaller Amplitude Dull Colors Higher Amplitude Bright Colors Higher Amplitude Bright Colors Created by Dr. Gordon Vessels 2004

9. Visible spectrum: 380-760 nm (nm is a billionth of a meter) The Electromagnetic Spectrum The Visible Spectrum Radar Television & Radio Bands AC Circuits Infrared Rays Ultraviolet Rays X - Rays Gamma Rays Wavelength in Nanometers Prepared by Dr. Gordon Vessels 2004

10. Retina (Rods & Cones) Cones Rods Number 6 million125 million Location in Retina CenterPeriphery Sensitivity to Light LowHigh Color Sensitive YesNo RetinaRetina Prepared by Dr. Gordon Vessels 2004

11. Photoreceptors Rods Light-sensitive High sensitivity –Perform in poor light Low acuity High concentration in periphery of retina Cones Color-sensitive Low sensitivity –Need bright light High acuity High concentration at the fovea Rods & cones connect to ganglion cells the axons of which comprise the optic nerve Prepared by Dr. Gordon Vessels 2004

12. Cross section of the central retina Ganglion cells Bipolar cells Photo Receptor cells Retina Bipolar cells Fovea Pigmented Epithelium RodsCones Arranged by Dr. Gordon Vessels 2004 Direction of Light Rays

13. Cells in the Retina Light Ganglion Cells Interneurons Bipolar Cells Prepared by Dr. Gordon Vessels 2004 Cone Rod

14. Receptive Field: retinal area that,, affects the firing of that cell when stimulated Receptive Field: retinal area that,, affects the firing of that cell when stimulated (+)(-) Visual Receptive Fields Lateral Inhibition: neural activity in a cell that inhibits activity in surrounding cells Lateral Inhibition: neural activity in a cell that inhibits activity in surrounding cells Arranged by Dr. Gordon Vessels 2004

15. Lateral Geniculate Nucleus Superior Culliculus in Midbrain Optic Radiation Pulvinar Nucleus Temporal Tempora Visual Cortex Nasal Optic Chiasm Right Visual Field Left Visual Field ○ Optic Nerve Localization of objects: from Optic Nerve to Superior Culliculus Superior Culliculus in Midbrain Primary Visual Cortex Superior Culliculus Lateral Geniculate Nucleus Optic Chiasm Optic Nerve General perception: from Optic Nerve to Optic Chiasm Arranged by Dr. Gordon Vessels 2004

16. Visual Information Processing Retinal Processing Rods & Cones  Bipolar Cells  Ganglion Cells Feature Detection Detector cells respond to elementary features Abstraction High-level cells respond to combined information from feature-detector cells Recognition Brain matches the constructed image with images stored in long-term memory Click here to learn more Prepared by Dr. Gordon Vessels 2004

17. Recap: How the Eye Works Light reflects off objects. Reflected light passes through pupil and lens to focus on the retina. Muscles change the shape of the lens to focus the image on the retina. Receptors in the retina (both rods & cones) change light into neural signals (transduction). Cones provide for visual acuity. Rods offer night vision + brightness information. Daytime vision is best at the fovea where cones are predominant. Arranged by Dr. Gordon Vessels 2004

18. Dark & Light Adaptation Adaptation happens when the eye grows more or less sensitive to light Modeled after a PPT slide created by Dr. Kevin Richardson in 1998 and available through the American Psychological Society. Time in Dark in Minutes Log Threshold in Microlamberts 8 7 6 5 4 3 51015202530

19. Absolute Thresholds Vision: On a clear, dark night you can see a candle from 30 miles away. What is the minimum stimulation necessary to detect a stimulus 50% of the time? Arranged by Dr. Gordon Vessels 2004

20. Detecting a weak signal from a stimulus depends on 1.The signal’s strength and 2. Your internal mental state (experience, motivation, mood, fatigue, needs, adaptation, etc. 1.The signal’s strength and 2. Your internal mental state (experience, motivation, mood, fatigue, needs, adaptation, etc. Do absolute thresholds really exist? Arranged by Dr. Gordon Vessels 2004

21. What is the minimum difference between two stimuli that a person can detect 50% of the time? Difference Thresholds (JND) (Ernst) Weber’s Law “Regardless of magnitude, two stimuli must differ by a constant proportion for the difference to be noticeable.” Arranged by Dr. Gordon Vessels 2004

22. Color Vision Do objects possess color? Is a lemon NO!!NO!! NO!!NO!! Light has no color. Is a chili pepper rrrrrrrr RED ? YELLOWYELLOW YELLOWYELLOW ? ? I said No !!!! Modeled after a PPT slide created by Dr. Kevin Richardson in 1998 and made available through the American Psychological Society

23. Trichromatic Theory ofColor VisionTrichromatic Theory ofColor Vision Helmholtz 1852 Three types of cone receptors are sensitive to different wavelengths of light different wavelengths of light. Short MediumLong People see colors because their eyes do mixing by adjusting the ratio of stimulus input from these three types of cones. Modeled after a PPT slide created by Kevin Richardson in 1998 and made available through the American Psychological Society

24. Opponent Process Theory RGRG BYBY BWBW Eye contains 3 mechanisms that produce antagonistic responses to three pairs of colors. Why? Afterimages and color deficiency Click here for more Arranged by Dr. Gordon Vessels 2004

25. Form Perception & Feature Analysis Bottom-Up Processing Relies on properties of the stimulus such as patterns of light and dark areas. Top-Down Processing Relies on higher-level information such as prior knowledge and experience. What is in this picture? Modeled after a PPT slide created by Kevin Richardson in 1998 and made available through the American Psychological Society

26. Perception of contours where there really are none. Is it really there? Subjective Contours Arranged by Dr. Gordon Vessels 2004

27. Lateral Inhibition in Action Click here to see more famous illusions Click here for more about illusions Arranged by Dr. Gordon Vessels 2004

29. An illusion invented by the German psychologist Wilhelm Wundt in the 19th century. In this figure, the two red horizontal lines are both straight, but they look as if they are bowed inwards. The distortion is induced by the crooked lines on the background. Arranged by Gordon Vessels, 2005

30. Size Height Linear Perspective Interposition Texture Gradient Shading Atmospheric Perspective Pictorial Cues Eye Muscles No Movement Movement Motion Parallax Kinetic Depth Effect Accommodation Convergence Retinal Disparity Monocular Cues Binocular Cues Source of Stimulation Twelve Types of Information That Help You Determine the Distance of an Object Arranged by Dr. Gordon Vessels 2004

31. Photographs combined by Dr. Gordon Vessels 2004

32. 3 Properties of Sound Sound also travels in waves 1. Pitch: is determined by wave “frequency,” the number of cycles per second of a sound wave. 2. Loudness: is determined by wave “amplitude” or the height of the sound waves. 3. Timbre: is determined by the “complexity and shape” of the sound waves, and it gives sound its unique quality. Arranged by Dr. Gordon Vessels 2004

33. Units of Measurement for Sound hertz (Hz): used to measure pitch (frequency), the number of cycles per second of the sound waves –a baby’s cry is at about 3,000 Hz decibel (db): reflects the loudness (amplitude) of the sound wave –Speech is at about 70 db Arranged by Dr. Gordon Vessels 2004

34. ● Revolver firing at close range ● PAIN THRESHOLD ● Sonic Boom ● Air Raid Siren ● Jackhammer 3 Feet Away ● Jet Plane 500 Feet Away ● Stereo at Full Volume ● Live Rock Music ● Subway Train 20 Feet Away ● Jackhammer 20 Feet Away ● Heavy Truck25 Feet Away ● Lawnmower, Food Blender ● POTENTIAL EAR DAMAGE ● Dog Barking 10 Feet Away ● Infant Crying Ten Feet Away ● Heavy Traffic, Vacuum Cleaner ● Doorbell 10 Feet Away ● Normal Conversation ● Window Air Conditioner ● Car Engine Idling ● Heavy Rain on Window ● Person walking on Hard Floor ● Knock at the Door ● Car on Highway Windows Up ● Light Rain on Window ● Person Talking in Closed Room ● Food Frying ● Leaves Rustling in Wind ● Whisper ● Clock Ticking ● Person Breathing Decibels of Sound 130 120 110 100 90 80 70 60 50 40 30 20 10 Arranged by Dr. Gordon Vessels 2004

35. Sound Waves Amplitude (Loudness) Strength or height of the wave Frequency (Pitch) Distance between consecutive peaks Mix (Timbre) Interaction of different waves 1 Hertz = 1 Cycle/Sec Human Hearing 20 - 20k Hz Arranged by Dr. Gordon Vessels 2004; modeled after a slide creared by Dr. Kevin Richardson (1998) and available through the American Psychological Society.

36. malleus cochlea incus pinna tympanic membrane auditory/8th nerve Outer Ear Tympanic Membrane Tympanic Membrane collects sound and vibrates the ossicles Pinna Pinna collects and directs sound into auditory canal Auditory Canal Auditory Canal amplifies and funnels sound to tympanic membrane auditory canal Modeled after a PPT slide created by Kevin Richardson in 1998 and made available through the American Psychological Society

37. Middle Ear Malleus Malleus – vibrates and moves the Incus Incus Incus – vibrates and moves the Stapes Stapes Stapes - vibrates against Oval Window of Cochlea Malleus Malleus – vibrates and moves the Incus Incus Incus – vibrates and moves the Stapes Stapes Stapes - vibrates against Oval Window of Cochlea malleusmalleusincusincus handle of malleus handle of malleus long process of incus long process of incus stapesstapes Modeled after a PPT slide created by Kevin Richardson in 1998 and made available through the American Psychological Society

38. Inner Ear lateral semicircular canal lateral semicircular canal posterior semicircular canal posterior semicircular canal vestibule anterior semicircular canal anterior semicircular canal cochleacochlea Cochlea Cochlea is filled with fluid & contains Hair-cell receptors for hearing Basilar Membrane Basilar Membrane divides length of cochlea and holds the hair cells Modeled after a PPT slide created by Kevin Richardson in 1998 and made available through the American Psychological Society

39. 3. The moving fluid sets the Basilar Membrane moving inside the Cochlea 2. The vibrating eardrum causes the bones of the middle ear to strike each other, amplifying and carrying the vibrations to the oval window and on the fluid in the coiled Cochlea of the Inner Ear. 1. The first stage of the hearing process is a series of vibrations. Sound waves enter the Outer Ear and travel to the Eardrum, causing it to vibrate. 5. The Auditory Nerve carries impulses to the brain. 6. When the nerve impulses reach the Temporal Lobe, they are interpreted as sounds. Cross-section of Cochlea Cochlear Nerve Basilar MembraneCochlear Nerve Fibers Organ of Corti Tectorial Membrane Hair Cells Eardrum Auditory Nerve Vestibular Organ Pinna Ear Canal Cochlea Extracted from Davis & Palladino text entitled Psychology; re-arranged for PPT by Dr. Gordon Vessels 2004 © 4. The Organ of Corti on top of the Basilar Membrane also moves. Inside the Organ of Corti, thousands of tiny receptor cells are topped by a bundle of hair-like fibers. As the Basilar Membrane vibrates, the fibers bend, stimulating the Receptor Cells to send a signal through afferent nerve endings, which join to form the Auditory Nerve

40. Hair Cell in the Organ of Corti Supporting Cells Hair Cells Efferent Nerve Ending Afferent Nerve Ending Cell Nuleus Hair Fibers Basilar Membrane Arranged by Dr. Gordon Vessels 2004

41. Stages in Audition External Ear (Pinnae) Middle Ear Inner Ear (Cochlea) Inner Hair Cells Type I Spiral Ganglion Cells Cochlear Nucleus (dorsal CN and ventral CN) Medial Nucleus of the Trapezoidal Body Lateral Superior Olivary Nucleus Medial Superior Olivary Nucleus Lateral Lemniscus Central Nucleus of the Inferior Colliculus Medial Geniculate Nucleus Auditory Cortex Slide # 3 Source: Erwin, Harry R (n.d.). The auditory system. A PPT slide set accessed online at http://www.cet.sunderland.ac.uk/~cs0her/Auditory%20System.ppt#1

42. Auditory Pathway Eustachion Tube Vestibular Cochlear Nerve Semicircular Canals Cochlea Stapes IncusEardrum StapesMalleus Pinna Lobule External Auditory Canal Arranged by Dr. Gordon Vessels 2004

43. Diana Deutsch is a Professor of Psychology at the University of California, San Diego who conducts research on perception and sound memory, including music. She discovered many musical illusions and paradoxes: the octave illusion, the scale illusion, the glissando illusion, the tritone paradox, and the cambiata illusion. She studies the way we hold music in memory and how we relate the sounds of speech and music. Her ongoing research focuses on the question of absolute pitch or why some rare individuals have it. Information retrieved from Dr. Deutsch at http://www-psy.ucsd.edu/%7Eddeutsch/University of California, San Diegomusical illusions and paradoxesoctave illusionscale illusionglissando illusion tritone paradoxcambiata illusionmemoryabsolute pitch The pattern that produces the cambiata illusion, and a way it is often perceived. Underlined words above are links to webpages Arranged by Dr. Gordon Vessels 2004 Pictures are copied from Dr. Deutsch’s CDs available online at the address above.

44. Exploring the Sense of Smell Olfactory Epithelium Olfactory Receptor Cells Olfactory Bulb Nasal Chache Bone Olfactory Nerve Olfactory Muccsa A Sniff Breathing In Normally Breathing Out Normally Olfactory Bulb Olffactory Bulb Arranged by Dr. Gordon Vessels 2005

45. Receptor Cilia Olfactory Epithelium Mucus Layer The Sense of Smell NEUROBIOLOGY Gary G. Matthews Blackwell Science Modified for PPT slide by Dr. Gordon Vessels Bone at Base of Skull Support Cells } } } Arranged by Dr. Gordon Vessels 2005 Basal Cell To Brain Olfactory Receptor Cell To Brain

46. Membrane Depolarization Odorant Receptor Protein Cilium of Olfactory Cell Adenylyl cyclase Ca 2+ Na + Ca 2+ Cl - c AMP Ca 2+ Na + Cl - Dendrite of Olfactory Cell cAMP ATP Ca 2+ Membrane Depolarization Arranged by Dr. Gordon Vessels 2005 Odorant Molecules G-Protein

47. Epithelial Cells Arranged by Dr. Gordon Vessels 2005 Sense of Smell Bone Olfactory Bulb Nerve Axons Cilia Sensory Cells Olfactory Nerve Volatile Molecules

48. (a) Taste buds line the trenches around tiny bumps on the tongue called papillae. (b) There are three types of papillae that are distributed on the tongue. The taste buds found in each show different sensitivities to the four basic tastes (see graph at the top). This sensitivity to the primary tastes varies across the tongue, but they are small. All four can de detected wherever there are taste receptors. (a) (b) Fungiform Papillae Circumvallate Papillae Foliate Papillae Taste Strength SweetSalty SourBitter Taste Buds Tongue The Sense of Taste Arranged by Dr. Gordon Vessels 2005

49. Top-Down versus Bottom-Up Perception Top-Down –Perceive the whole and then individual parts as needed. –Experience-driven as opposed to stimulus or input- data driven. –Quick and highly inferential but also a source of misperception. Bottom-up –Perceive the individual parts and organize them into a whole, if possible. –Information available in the stimulus itself. Top-Down –Perceive the whole and then individual parts as needed. –Experience-driven as opposed to stimulus or input- data driven. –Quick and highly inferential but also a source of misperception. Bottom-up –Perceive the individual parts and organize them into a whole, if possible. –Information available in the stimulus itself. Arranged by Dr. Gordon Vessels 2005

50. Bottom-Up Processing Prior Knowledge, Experience, etc. Stimuli Processing Perception Stimuli Input Created by Dr. Gordon Vessels 2005

51. David Marr’s Computational Bottom-Up Approach Marr wanted to understand mechanisms of vision rather than just behaviors associated with it. …he wanted to link neurophysiology with psychology. He took an information processing view of the mind… …and aimed to describe perception in terms of computations on sense data… …to extract high level visual experience. Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

52. Marr’s Stages of Visual Processing Marr proposed there were distinct stages of processing in visual perception: » Stage 1: Raw Primal Sketch » Stage 2: Complete Primal Sketch » Stage 3: 2½D Sketch » Stage 4: Full 3D Representation Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

53. Stage 1: Raw Primal Sketch This involves the extraction of information regarding edges and intensity changes. Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

54. Stage 2: Complete Primal Sketch After the Raw Primal Sketch… Marr [proposed]… we create a Complete Primal Sketch by grouping surfaces and common areas. The Gestalt Psychologists of the early 19th Century demonstrated many different ways in which we can group objects. Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

55. Stage 3: 2½D Sketch After gaining information about groupings and surfaces, the viewer needs some spatial information. Marr called this stage the 2½D Sketch to emphasis that this stage does not give a full 3D representation. Rather, just an estimate of the spatial locations of objects and materials in relation to the viewer. Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

56. 2½ D Sketch: Depth Cues We perceive much information from which we infer depth: » Binocular disparity » Texture gradients » Occlusion » Convergence » Relative Size We perceive much information from which we infer depth: » Binocular disparity » Texture gradients » Occlusion » Convergence » Relative Size Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

57. Stage 4: 3D Representation The final stage of Marr’s theory. A full 3D description of our spatial environment involving the identification of the structure of objects and materials in our visual field. It allows us to work out the 3D environment from a non-egocentric point-of-view. Source: Bell, Vaughan (2004). Perception and perceptual distortion. A PPT presentation retrieved at http://www.cardiff.ac.uk/psych/home/bellv1/ Used here with the author’s written permission. Slide arrangement by Vessels, 2005.

58. Gregory on Top-Down Perception Gregory proposes that we use our prior “experience of the world to shape how we perceive” stimuli we encounter in it. His theory of perception is called Top-Down, Which means we use activated conceptual schemas and memory networks (our stored knowledge), more or less automatically and subconsciously, to shape our perceptions or to interpret our sensory input ― sometimes correctly and sometimes not. He confirmed many of his theoretical propositions using visual illusion research. Primary source Bell, Vaughan (2004). Perceptions and perceptual distortions, a PPT show accessed at http://www.cf.ac.uk/psych/home/bellv1/conf/VaughanPerceptionLecture2004.ppt#1. Written permission granted 5-5-05.

59. Top-Down Processing Stimuli Processing Perception Stimuli Input Prior Knowledge, Experience, etc. Prior Knowledge, Experience, etc. Personality Temperament Culture Social Class Values Beliefs Prejudices Attitudes Immediate Mental Set Presence of Authority Present Fatigue Energy Level Prior Stimuli Perceived Occupation Education Needs, Moods Mental Health Knowledge Vocabulary Specific Life Experiences Long-term Memory Schemas Created by Dr. Gordon Vessels 2005

60. If all of these people were at the same football game, who among them was most likely to have perceived what actually happened on a controversial play where the receiver may have fumbled the ball before his knees touched the ground? Whose perceptions were the most bottom up? Whose perceptions were the most top-down and thus influenced and quickened in terms of inference by their present needs, biases, and heightened emotion? Whose perception may have been the most accurate and objective based on his or her knowledge of the game? When the head referee reviewed the replays, did he use top- down or bottom-up perception primarily? What top-down influence may have made it possible for his perceptions to have been highly accurate? Did these people literally see something different? Do they really believe what they claimed to have seen?

61. What do you see? A face looking down? The word Liar in script or cursive? Those who first read stories about deception were more inclined than others to see the word Liar. What do you see? The word liar in script or cursive? A face looking down? Those shown artwork with faces were more inclined than others to see the word liar. Arranged by Dr. Gordon Vessels 2004

62. Top-Down & Bottom-Up Processing Prior Knowledge, Experience, etc. Stimuli Processing Perception Stimuli Input Created by Dr. Gordon Vessels 2005