1. Chapter 4 Sensation and Perception PSYCHOLOGY Schacter Gilbert Wegner Brian Kelley, M.A., LPC

2. PSYCHOLOGY Schacter Gilbert Wegner 4.1 The Doorway to Psychology

3. 3 4.1 The Doorway to Psychology - Sensation - Perception - Transduction - Psychophysics Gustav Fechner

4. 4 4.1 The Doorway to Psychology - Measuring thresholds boundary between two psychological states - Absolute threshold minimal intensity needed to just barely detect a stimulus - Just noticeable difference Weber’s Law (constant proportion)

5. 5 4.1 Sensory Adaptation - Sensory adaptation current conditions emphasize change

6. PSYCHOLOGY Schacter Gilbert Wegner 4.2 Vision: More Than Meets the Eye

7. 7 4.2 Vision - Visual acuity - Sensing light - Properties of light waves length amplitude purity

8. 8 4.2 The Human Eye - Cornea - Pupil - Light adaptation - Retina - Accommodation - Cones - Rods - Fovea

9. 9 4.2 The Human Eye - Blind spot - Receptive field - Lateral inhibition - Seeing in color additive color mixing subtractive color mixing - Trichromatic color representation - Color-opponent system

10. 10 4.2 Visual Pathway From Eye Through Brain

11. 11 4.2 Pathways - Visual streams - Ventral (below) stream across occipital lobe into lower levels of temporal lobes (shape and identity) - Dorsal (above) stream travels up from occipital lobe to parietal lobes (location and motion)

12. 12 4.2 Recognizing Objects by Sight - Visual-form agnosia - The importance of object recognition without it, all information would require effortful processing - Feature detectors modular view (specialized cells?) distributed representation (pattern of activity)

13. 13 4.2 Recognizing Objects by Sight - fMRI studies of the 1990s some brain regions do respond selectively to specific object categories - Perceptual constancy sensitive to change but notice the differences

14. 14 4.2 Principles of Perceptual Organization - Before object recognition can occur, grouping of images must occur - Gestalt perceptual grouping rules

15. 15 4.2 Principles of Perceptual Organization - Grouping involves visually separating an object from its surroundings - Separating “figure” from “ground” size edge assignment

16. 16 4.2 Theories of Object Recognition - Image-based template what if we’ve never seen it before? - Parts-based brain deconstructs image into parts

17. 17 4.2 Perceiving Depth and Size - Monocular cues to depth Linear perspective (a) Texture gradient (b) Interposition (c) Relative height in the image (d)

18. 18 4.2 Perceiving Depth and Size - Binocular depth cues binocular disparity having space between the eyes means that each eye registers a slightly different view of the world the difference in these views provides the brain with important and direct information about depth

19. 19 4.2 Motion-Based Depth Cues - Motion parallax - Optic flow

20. 20 4.2 Illusions of Depth and Size - Ames Room - Moon illusion

21. 21 4.2 Perceiving Motion - Waterfall effect - Phi phenomenon - Common fate - Apparent motion

22. PSYCHOLOGY Schacter Gilbert Wegner 4.3 Audition: More Than Meets the Ear

23. 23 4.3 Sensing Sound - Three physical dimensions of sound frequency amplitude complexity - These determine what we hear pitch loudness timbre

24. 24 4.3 The Human Ear

25. 25 4.3 Auditory Transduction - Cochlea - Basilar Membrane - Hair cells

26. 26 4.3 Perceiving Pitch - Area A1 - Normal range 20 - 16,000 Hz - Place code - Temporal code

27. PSYCHOLOGY Schacter Gilbert Wegner 4.4 The Body Senses: More Than Skin Deep

28. 28 4.4 Touch - Haptic perception – up close & personal! - Thermoreceptors - Neural representation of the body’s surface contralateral organization somatosensory representation (fingers vs. back)

29. 29 4.4 Pain - A-delta fibers (fast acting pain) - C fibers (longer lasting pain) - Referred pain - Gate-control theory periacqueductal gray bottom-up control top-down control

30. 30 4.4 Body Position, Movement, and Balance - Vestibular system semicircular canals

31. PSYCHOLOGY Schacter Gilbert Wegner 4.5 The Chemical Senses: Adding Flavor

32. 32 4.5 Smell - Only sense directly connected to forebrain - Olfactory receptor neurons (ORNs) glomerulus 350 different ORNs (humans) - Olfactory bulb - Pheromones

33. 33 4.5 Taste - Identifying things that are “bad” for you - Taste buds (5 different types) salt sour bitter sweet umami (savory) each contains several types of taste receptors (microvilli) that react with tastant molecules in food