Myers’ PSYCHOLOGY for AP

1. Myers’ PSYCHOLOGY for AP Unit 4 Sensation & Perception Sight, Smell, Taste, Touch, Hearing.  If you had to do without one, which would it be? 

2. Sensation Sensation: detecting stimuli from the body or surroundings. Perception: interpreting and organizing sensations into meaningful patterns.

3. Sensation • Sensation • a process by which our sensory receptors and nervous system receive and represent stimulus energy • Perception • a process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

4. Sensation • Our sensory and perceptual processes work together to help us sort out complex processes

5. What if we could sense everything? Life would hurt. So we can only take in a window of what is out there. Psychophysics: studies the relationship between physical stimuli and our psychological experiences to them.

6. Sensation • Bottom-Up Processing • analysis that begins with the sense receptors and works up to the brain’s integration of sensory information • Top-Down Processing • information processing guided by higher-level mental processes • as when we construct perceptions drawing on our experience and expectations

7. Top-Down Processing • For example, stereotyping since both previous expectations to make judgements about the world around us. • Stereotyping can be negative, it can also be efficient for people as they interact with certain stimuli. • Without top down processing, we would interpret the world as if it were constantly new. • Like learning how to add everyday in math or 50 First Dates! https://www.youtube.com/watch?v=ErjP5xMTc8I Remember, TDP - we process this way when we have prior knowledge. We start at the top and have to work to process details.

8. Stroop Effect On the next slide, you are to follow the instructions below: Look at the image and say aloud the color of each word. Do not read the words! Just say what color they are.

10. Stroop Effect: How does it work? • The words themselves interfere with your ability to quickly say the correct color of the word. Two different theories have been proposed to explain this phenomenon: • Selective Attention Theory: According to this theory, naming the actual color of the words requires much more attention that simply reading the text. • Speed of Processing Theory: According to this theory, people can read words much faster than they can name colors. The speed at which we read makes it much more difficult to then name the color of the word.

11. Be the Experimenter… Consider the following: • Try the experiment with a young child that has not yet learned to read. How does the child's reaction time compare to that of an older child who has learned to read? • Try the experiment with uncommon color names, such as lavender or chartreuse. How do the results differ from those who were shown the standard color names?

12. Bottom Up Processing • BUP is when we have no prior knowledge. We start at the bottom and work our way up. • Also called “small chunk” or “data” processing. http://www.youtube.com/watch?v=yKBYL7QnFkE – watch on your own!

13. Perception • Selective Attention focus of conscious awareness on a particular stimulus • Those with ADHD have an inability to be selectively attentive. Instead of attending to the important stimuli and filtering out unimportant ones, they attend to all stimuli in the environment making it difficult to process information correctly.

14. Try this… Instructions… 1. Do NOT talk OR YOU will ruin it for others. 2. Pay attention to what I am going to play for you. 3. Listen and do what the Video tells you to. http://www.youtube.com/watch?v=IGQmdoK_ZfY

15. Change Blindness • Is a psychological phenomenon that occurs when a change in a visual stimulus goes unnoticed by the observer. • For example, an individual fails to notice a difference between two images that are identical except for one change. • The reasons these changes usually remain unnoticed by the observer include obstructions in the visual field, eye movements, a change of location, or a lack of attention. • The brain regions that have been observed as active during change blindness are the prefrontal lobe, the cerebellum, the inferior temporal gyrus, the parietal lobe, and the frontal lobe. http://www.youtube.com/watch?v=VkrrVozZR2c

16. Selective Attention & Flow • These concepts are related… • When people get caught up in an experience that they miss out an obvious stimuli in the environment, they are said to be having a flow experience. • Flow is coined by Mihaly Csikszentmihalyi and involves being skilled at a challenging task that takes away our sense of self consciousness and awareness of time and the presence of others around us.

17. Selective Attention & the Evolutionary Perspective • If we had to attend to every stimulus in the environment (noise), we might be hindered from action. • However, if we miss important stimuli in the environment due to attention that is too selective, we may fall victim to all sorts of trouble…falls, car accidents etc.

18. Is there a gender difference in selective attention?

19. Sensation- Basic Principles • Psychophysics • study of the relationship between physical characteristics of stimuli and our psychological experience of them • Light- brightness • Sound- volume • Pressure- weight • Taste- sweetness

20. Gustav Fechner Established 3 methods of experimental measurement used to study sensory phenomena. • Method of Limits – begin with minimal stimulus and increase it until the subject can perceive it. – Determines JND • Method of Right and Wrong Cases – present identical stimuli repeatedly – either single stimuli at the threshold or pairs of stimuli that are very similar. The subject responds “yes” if perceived or if a difference exists or “no” if not perceived or different. • Method of Adjustment – adjust a comparison stimulus until it appears identical to the standard stimulus. Every error is recorded and after many trials, the average error is computed. It too, provides a measure of JND.

21. Sensation- Thresholds • Absolute Threshold • minimum stimulation needed to detect a particular stimulus 50% of the time • Difference Threshold • minimum difference between two stimuli required for detection 50% of the time • just noticeable difference (JND)

22. Why Do We Care About Signal Detection? • Extremely important in fields where attention to detail amid environmental distractions is paramount – air traffic controllers, policemen, drivers etc.

23. Sensation- Thresholds • Signal Detection Theory • predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise) • assumes that there is no single absolute threshold • detection depends partly on person’s • experience • expectations • motivation • level of fatigue

24. 100 Percentage of correct detections 75 50 Subliminal stimuli 25 0 Low Absolute threshold Medium Intensity of stimulus Sensation- Thresholds • Subliminal • When stimuli are below one’s absolute threshold for conscious awareness • http://www.youtube.com/watch?v=1NpBMAKdgnQ • While sub messaging may not work, priming does. If we are exposed to stimuli about a specific subject we are more likely to recognize information about that subject in the environment.

25. Anthony Pratkanis & Factors Contributing to Public’s Beliefs of Subliminal Influence • Popular accounts of subliminal influence appeal to the pop psychology of the day. • Popular accounts link subliminal influence to the issue of the day. • Many of the popular articles fail to report scientific evidence that is critical of claims for subliminal persuasion. • Belief in subliminal persuasion may serve as a need for many individuals.

26. Sensation- Thresholds • Weber’s Law- to perceive as different, two stimuli must differ by a constant minimum percentage • light intensity- 8% • weight- 2% • tone frequency- 0.3% • Everyone…take off 1 shoe, take out 3 quarters… • Sensory ADAPTation- diminished sensitivity as a consequence of constant stimulation

27. Sensory Adaptation • Tendency of sensory receptors to respond less and less to constant stimulation. Do you feel your underwear all day?

28. Sensory Adaptation • ADAPTation—habituation • After drinking tea with lemon, a grapefruit will not taste as sour • …but after a roll, it will taste especially sour • After holding salty water in mouth, it will taste less salty, and drinking fresh water afterwards, it will taste sweet

29. Vision • Our most dominating sense (Visual Capture). • The eye is like a camera (it needs light).

30. Vision- Stabilized Images on the Retina

31. Vision • Transduction • conversion of one form of energy to another • in sensation, transforming of stimulus energies into neural impulses • Wavelength • the distance from the peak of one wave to the peak of the next

32. Vision • Hue • dimension of color determined by wavelength of light • Intensity • amount of energy in a wave determined by amplitude • brightness • loudness

33. The spectrum of electromagnetic energy

34. Great amplitude (bright colors, loud sounds) Short wavelength=high frequency (bluish colors, high-pitched sounds) Long wavelength=low frequency (reddish colors, low-pitched sounds) Small amplitude (dull colors, soft sounds) Vision- Physical Properties of Waves

35. Think Rainbow!

36. Wavelength & Amplitude Helpful Hints • Vision & Audition use similar terms to discuss the different stimuli that are processed by our visual and auditory systems. They both work in waves. • Wavelength – determines the quality of the waves (for vision, colour, for sound pitch) • Amplitude – determines the intensity of the waves (for vision, brightness, for sound, loudness)

37. Vision • Pupil- adjustable opening in the center of the eye • Iris- a ring of muscle that forms the colored portion of the eye around the pupil and controls the size of the pupil opening • Lens- transparent structure behind pupil that changes shape to focus images on the retina

38. Vision

40. Vision • Accommodation- the process by which the eye’s lens changes shape to help focus near or far objects on the retina • LINK! In sensation, accommodation refers to the ways the muscles in the way the eye change the shape of the lens BUT it can also refer to the ways in which we change our schemas to incorporate new information we learn. • Retina- the light-sensitive inner surface of the eye, containing receptor rods and cones plus layers of neurons that begin the processing of visual information

41. Vision • Acuity- the sharpness of vision (fovea!) • Nearsightedness- condition in which nearby objects are seen more clearly than distant objects because distant objects in front of retina • Farsightedness- condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind retina

42. Vision • Normal Nearsighted Farsighted Vision Vision Vision

43. Retina’s Reaction to Light- Receptors • Rods • peripheral retina • detect black, white and gray • twilight or low light • Cones • near center of retina • fine detail and color vision • daylight or well-lit conditions

44. More About the Retina! • The cells that make up the retina seem backward. • Rods and Cones located at back of retina. • Then, bipolar and ganglion cells are on top forming layers. • Light is interpreted by the rods and cones first, even though it actually passes through the other layer first!

45. Retina’s Reaction to Light • Optic nerve- nerve that carries neural impulses from the eye to the brain • Blind Spot- point at which the optic nerve leaves the eye, creating a “blind spot” because there are no receptor cells located there • Fovea- central point in the retina, around which the eye’s cones cluster

47. Receptors in the Human Eye Cones Rods Number 6 million 120 million Location in retina Center Periphery Sensitivity in dim light Low High Color sensitive? Yes No Vision- Receptors

48. Pathways from the Eyes to the Visual Cortex

49. Cell’s responses Stimulus Visual Information Processing • Feature Detectors • nerve cells in the brain that respond to specific features • shape • angle • Movement • Visual Capture • tendency for vision to dominate the other senses

50. Blindsight • Is the ability to respond to visual information without consciously seeing it. • Anthony Marcel argues that those people have superb vision but they don’t know they can see. • His research suggests that their vision remains in tact only the neural areas that bring vision into awareness are impaired. • Acquired through damage. http://www.youtube.com/watch?v=R4SYxTecL8E