1 / 43

Sensation & Perception

Sensation & Perception. Myers Chapter 6 Additional information from Lilienfeld, Lynn, Namy, & Wolf (2011). Sensation vs. Perception. Sensation : how our sensory receptors and nervous system receive and represent stimulus energies from our environment

nicki
Download Presentation

Sensation & Perception

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Sensation & Perception Myers Chapter 6 Additional information from Lilienfeld, Lynn, Namy, & Wolf (2011)

  2. Sensation vs. Perception • Sensation: how our sensory receptors and nervous system receive and represent stimulus energies from our environment • Perception: how we organize and interpret sensory information

  3. What Illusions Suggest • What we sense is not necessarily what we perceive • The sensory information must be manipulated in some way to create our mental representations • Our representations depend upon our viewpoint

  4. Sensation • The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

  5. Bottom-up Processing • Analysis that begins with the sense receptors and works up to the brain’s integration of sensory information • Construct a whole stimulus from its parts

  6. Top-down Processing • Information processing guided by our experience and expectations • Starts with our beliefs and expectations

  7. Top-down Processing • Aoccdrnig to rscheearch at Cmabrigde uinervtisy, it deosn't mttaer waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteres are at the rghit pclae. The rset can be a tatol mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by it slef but the wrod as a wlohe.

  8. Transduction • The process by which the nervous system converts an external energy or substance into electrical activity within neurons

  9. Sensing the World: Basic Principles • Psychophysics: the study of the relationship between physical energy and psychological experience

  10. Proportion of “Yes” Responses 0.00 0.50 1.00 0 5 10 15 20 25 Stimulus Intensity (lumens) Absolute Threshold • The minimum stimulation needed for the nervous system to detect a stimulus 50% of the time

  11. Absolute Threshold • Variability in the absolute threshold • Changing sensitivity • Lapses of attention • Slight fatigue • Psychological changes • Age

  12. Just-noticeable Difference (jnd) • The minimum difference between two stimuli that a person can detect 50% of the time • Difference threshold

  13. Weber’s Law • There is a constant proportional relationship between the jnd and the intensity of the original stimulus • Light intensity 8% • Weight 2% • Tones .3%

  14. Signal Detection Theory (Green & Swets, 1966) • Predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise) • No single absolute threshold

  15. Signal Detection Theory (Green & Swets, 1966) • Individual threshold depends upon several variables • Experience • Expectations • Motivation • Level of fatigue

  16. Signal Detection Theory (Green & Swets, 1966)

  17. Subliminal Threshold When stimuli are below one’s absolute threshold for conscious awareness

  18. Proportion of “Yes” Responses 0.00 0.50 1.00 0 5 10 15 20 25 Stimulus Intensity (lumens) Priming • The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response

  19. Sensory Adaptation • Activation of our senses is greatest when we first detect a stimulus • Diminished sensitivity as a consequence of constant stimulation

  20. Sensory Adaptation

  21. Sensory Interaction • Multi-modal Perception • One sense may influence another • Smell of food influences its taste • McGurk Effect

  22. Perceptual Set • Set formed when expectations influence perceptions

  23. Perceptual Constancy • The process by which we perceive stimuli consistently across varied conditions Changes in stimulus + Constants = Precise info.

  24. Size Constancy • Our perception that the size of a stimulus remains the same although our proximal stimulus has changed in size

  25. Shape Constancy • An object retains the same shape although the proximal stimulus has changed in shape • As when a door opens toward us

  26. Color Constancy • Our ability to perceive color consistently across different levels of lighting

  27. Selective Attention • Process of selecting one sensory channel and ignoring or minimizing others • Cocktail party effect • Inattentional blindness (Simons & Chabris, 1999, 2010)

  28. Perceptual Organization • Gestalt: an organized whole • Psychological perspective: emphasized our tendency to integrate pieces of information into meaningful wholes Our brain does more than register information about the world

  29. Figure-Ground

  30. Proximity O O O O O O O

  31. Similarity X O X O X O X O X O X O X O X O

  32. Continuity or Connectedness

  33. Closure

  34. Depth Perception • Depth: the distance from a surface • Use of depth extends beyond our body as we interact with the world • Driving - when to brake • Walking across the parking lot - how loudly do greet friend

  35. Visual cliff: experimental apparatus that gives an illusion of a sudden drop-off between one horizontal surface and another (Gibson & Walk, 1960) Depth Perception 35

  36. Texture Gradient

  37. Relative Size

  38. Interposition/Occlusion

  39. Linear Perspective

  40. Aerial Perspective

  41. Location in the Picture Plane

  42. Binocular Cues (2) • Binocular Convergence • Item perceived as closer when our eyes are pulled toward our nose • Item perceived as farther away when our eyes relax more toward our ears • Binocular Disparity • Huge discrepancy between L and R eye as object appears closer • Less discrepancy between eyes as object appears farther away

  43. Ames Room • Perceived distance (based on the cues of the environment) influences the apparent size of the children • Size and distance are interdependent

More Related