Chapter 3 Sensation and Perception 2013 by Mc
Chapter 3 Sensation and Perception © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 1
Chapter Preview • How We Sense and Perceive the World • The Visual System • The Auditory System • Other Senses © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 2
Sensation and Perception • Sensation • Process of receiving stimulus energies from external environment • Perception • Process of organizing and interpreting sensory information © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 3
Sensation & Perception: Processes • Bottom-Up Processing • Information about external environment Sensory receptors Brain • Making sense of information • Top-Down Processing • Starts with cognitive processing at higher levels of brain • Video: http: //www. youtube. com/watch? v=h 8 s. XGy. Mib. DM © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 4
Sensation & Perception: Purpose • Adaptation • Improves a species’ chances for survival • An organism must be able to sense and respond quickly © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 5
Sensory Receptors and the Brain • Sensory receptors • Specialized cells that detect stimulus information and transmit it to sensory (afferent) nerves and brain • Openings through which the brain and nervous system experience the world © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 6
Figure 3. 1 - Human Senses © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 7
Sensation • Photoreception • Detection of light • Perceived as sight • Mechanoreception • Detection of pressure, vibration, and movement • Perceived as touch, hearing, and equilibrium • Chemoreception • Detection of chemical stimuli • Perceived as smell and taste © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 8
‘Confused’ Senses • Synaesthesia • One sense induces experience in another sense • Phantom Limb Pain • Reported pain in amputated arm or leg • Extrasensory perception (ESP) • Perception in absence of concrete sensory input © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 9
Thresholds • Absolute threshold • Minimum amount of detectable stimulus energy • Difference threshold (Just noticeable difference) • Degree of difference that must exist between two stimuli before difference is detected © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 10
Figure 3. 4 - Approximate Absolute Thresholds for Five Senses © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 11
Thresholds • Weber’s Law • Principle that two stimuli must differ by a constant minimum percentage to be perceived as different • Subliminal Perception • Detection of information below level of conscious awareness © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 12
Signal Detection Theory • Theory of perception which focuses on decision-making about stimuli in presence of uncertainty • Possible outcomes: • • Hit Miss False alarm Correct rejection © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 13
Figure 3. 5 - Four Outcomes in Signal Detection © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 14
Perception of Sensory Stimuli • Attention • Selective • Cocktail party effect • Shiftable • Novelty, size, color, movement • Inattentional blindness © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 15
Perception of Sensory Stimuli • Culture influences which stimuli we attend to as we perceive the world • Perceptual set • Predisposition or readiness to perceive something a particular way © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 16
Other Perceptual Phenomena • Sensory adaptation • Change in responsiveness of sensory system based on average level of surrounding stimulation © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 17
• Is It Top-down or Bottom-up? • • Susie sets up a disk to record her favorite television show. Top-down or Bottom-up • Melissa’s mom is showing Rebecca how to make the family favorite of molasses cookies. She walks Rebecca through the recipe step-by-step. Top-down or Bottom-up • • Tim decides he is going to start a business of putting bicycles together. He reads the instructions carefully and follows them very closely. Top-down or Bottom-up It’s been two years and Tim’s bicycle business is doing very well. He can now go through five to eight bicycle assemblies a day without looking at any instructions. Top-down or Bottom-up Jeremy is in his first year of algebra and finds the problems very confusing. He finds that he needs to keep going back to the textbook and seeing what steps are next. Top-down or Bottom-up © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 18
• END part one © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 19
The Visual Stimulus • Light • Form of electromagnetic energy • Wavelength • Amplitude • Purity Hue, or color Brightness Saturation, or richness © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 20
Figure 3. 6 - The Electromagnetic Spectrum and Visible Light © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 21
Structure of the Eye • Sclera • White, outer part of eye • Helps maintain shape of eye • Protects eye from injury • Iris • Colored part of eye • Pupil • Opening in center of iris • Size controlled by muscles in iris © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 22
Structure of the Eye • Cornea • Clear membrane just in front of eye • Lens • Transparent, somewhat flexible, disk-like structure • The cornea and the lens both bend light falling on the surface of the eye just enough to focus it on the retina © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 23
Structure of the Eye • Retina • Multilayered, light-sensitive surface at back of eye • Converts visual stimuli to neural impulses © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 24
Figure 3. 9 - Parts of the Eye © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 25
Visual Receptor Cells • Cells on retina which convert electromagnetic energy into electrochemical impulses • Rods • Sensitive to light • Not very useful for color vision • Function well under low illumination • Cones • Used for color perception • Require more light than rods © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 26
Structure of the Eye: Retina • Fovea • Tiny area in center of retina at which vision is best • Contains only cones Rods & cones Bipolar cells Ganglion cells Optic nerve • Blind spot • Place on retina containing neither rods nor cones • Where optic nerve leaves eye © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 27
Figure 3. 11 - Direction of Light in the Retina © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 28
Visual Processing Optic Nerve Optic Chiasm Visual Cortex Optic nerve fibers divide at optic chiasm: • Left Visual Field Right Hemisphere • Right Visual Field Left Hemisphere © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 29
Figure 3. 14 - Visual Pathways to and Through the Brain © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 30
Visual Processing • Feature detectors • Neurons in primary visual cortex that respond to particular features of a stimulus • Parallel processing • Simultaneous distribution of information across different neural pathways • Binding • Integration of what is processed by different pathways or cells © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 31
Color Vision: Trichromatic Theory • Three types of cones, sensitive to different (but overlapping) ranges of wavelength • Support includes: • Color matching • Color blindness © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 32
Color Vision: Opponent-Process Theory • Afterimages • Sensations that remain after stimulus is removed • Not explained by trichromatic theory • Explained by opponent-process theory • Visual system treats colors as complementary pairs • Conclusion: Both theories are correct © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 33
Perceiving Shape • Contour • Location at which sudden change of brightness occurs • Figure-ground relationship • Principle by which perceptual field is organized into stimuli that stand out (figure) and those left over (ground) © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 34
Perceiving Shape • Gestalt psychology • School of thought interested in how people naturally organize perception according to certain patterns • ‘Whole is different from sum of its parts’ © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 35
Figure 3. 18 - Reversible Figure-Ground Pattern © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 36
Figure 3. 19 - Gestalt Principles of Closure, Proximity, and Similarity © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 37
Perceiving Depth • Ability to perceive objects three-dimensionally • Binocular Cues combined images from two eyes • Disparity • Convergence © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 38
Perceiving Depth • Monocular Cues available from image in one eye • • • Familiar size Height in field of view Linear perspective and relative size Overlap Shading Texture gradient © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 39
Perceiving Motion • • • Retinas of humans cannot detect movement Neurons specialized to detect motion Feedback from body Environment rich in cues Real movement Apparent movement • Perception of stationary object as moving © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 40
Perceiving Constancy • Recognition that objects are constant even though sensory input is changing • Size constancy • Same size despite retinal image changes • Shape constancy • Same shape despite orientation changes • Color constancy • Same color despite light changes © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 41
The Nature of Sound • Vibrations in air processed by auditory system • Wavelength Frequency Pitch • Amplitude Pressure Loudness • Complexity Saturation Timbre © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 42
Figure 3. 25 - Physical Difference in Sound Waves and the Qualities of Sound They Produce © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 43
Structure of the Ear • Outer Ear sound Collects and channels • Pinna • External Auditory Canal • Middle Ear ear Channels sound to inner • Eardrum • Hammer, Anvil, & Stirrup © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 44
Structure of the Ear • Inner Ear neural impulses Converts sound into • Oval Window • Cochlea • Basilar Membrane Hair Cells Tectorial Membrane © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 45
Figure 3. 26 – The Outer, Middle, and Inner Ear © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 46
Theories of Hearing • Place theory • Each frequency produces vibrations at a particular spot • Explains high-frequency, not low-frequency sounds • Frequency theory • Perception of frequency depends on how often auditory nerve fires • Single neurons have maximum firing rates © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 47
Theories of Hearing • Volley principle • Modification of frequency theory • Clusters of nerve cells can fire neural impulses in rapid succession © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 48
Auditory Processing • Inner Ear Auditory Nerve Temporal Lobe • Most fibers cross over midline between hemispheres: • Left Ear Right Hemisphere • Right Ear Left Hemisphere • Some fibers go directly to same-side hemisphere © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 49
Localizing Sound Each ear receives somewhat different stimuli • Distance • Sound Shadow Timing Intensity © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 50
Other Senses • Skin (Cutaneous) • Touch • Temperature • Pain • Chemical • Smell • Taste © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 51
Other Senses • Kinesthetic • Vestibular © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 52
The Skin (Cutaneous) Senses • Touch • Mechanical energy, or pressure, against skin • Temperature • Warm and cold sensory nerve endings, or thermoreceptors © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 53
The Skin (Cutaneous) Senses • Pain • Widely-dispersed receptors with much higher thresholds for different types of physical stimuli (e. g. , pressure, heat) © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 54
Pain • Prostaglandins • Stimulate pain receptors and cause experience of pain • Neural pathways to brain • Fast Pathway • Slow Pathway Directly to thalamus Through limbic system © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 55
Pain • Endorphins • Neurotransmitters involved in turning pain signals on/off © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 56
Chemical Senses: Taste • Detecting chemicals dissolved in saliva • Papillae • Bumps on surface of tongue • Contain taste buds, receptors for taste • Four taste qualities: sweet, sour, bitter, salty • Taste fibers respond to range of chemicals spanning multiple taste elements • Umami © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 57
Chemical Senses: Smell • Detecting airborne chemicals • Olfactory epithelium • Lines roof of nasal cavity • Contains sheet of receptor cells • Neural pathway • Olfactory areas of temporal lobe Limbic system • Superhighway to emotion & memory • Interpersonal attraction & MHC genes © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 58
Figure 3. 30 - The Olfactory Sense © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 59
Kinesthetic and Vestibular Senses • Kinesthetic sense • Information about movement, posture, orientation • Vestibular sense • Information about balance, movement © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 60
Kinesthetic and Vestibular Senses • Proprioceptive feedback • Information about relative position of limbs and body • Semicircular canals • Contain sensory receptors to detect head motion © 2013 by Mc. Graw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. 61
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