1. Sensation Sensation: your window to the world Perception: interpreting what comes in your window.

2. Sensation  Our sensory and perceptual processes work together to help us sort out complex processes

3. 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

4. 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

5. 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)

6. 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

7. Signal Detection Theory Absolute thresholds are not really absolute. Things like motivation or physical state can effect what we sense. False Positives False Negatives My wife could sleep through a war, but if of our dog barks, she is up!!!

8. Sensation- Thresholds  Subliminal  When stimuli are below one’s absolute threshold for conscious awareness 0 25 50 75 100 LowAbsolute threshold Medium Intensity of stimulus Percentage of correct detections Subliminal stimuli

9. 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%  Sensory adaptation- diminished sensitivity as a consequence of constant stimulation

10. Weber’s Law Computes the Just Noticeable Difference (JND) The change needed is proportional to the original intensity of the stimulus. The more intense the stimulus the more change is needed to notice the difference. 8% for vision.

11. Transduction Transforming signals into neural impulses. Information goes from the senses to the thalamus, then to the various areas in the brain. Remember Ethan in Sky High. He changes his body to slime. Solid form to liquid form. Change from one form of energy to another. Click the picture to watch power placement.

12. Sensory Adaptation Decreased responsiveness to stimuli due to constant stimulation. Do you feel your underwear all day?

13. Energy v. Chemical senses Energy SensesChemical Senses

14. VisionVision Our most dominating sense Visual Capture

15. Phase One: Gathering Light The height of a wave gives us it’s intensity (brightness). The length of the wave gives us it’s hue (color). The longer the wave the more red. The shorter the wavelength the more violet.

16. Phase Two: Getting the light in the eye

17. Phase Three: Transduction

18. Transduction Continued Order is Rods/Cones to Bipolar to Ganglion to Optic Nerve. Sends info to thalamus- area called lateral geniculate nucleus (LGN). Then sent to cerebral cortexes. Where the optic nerves cross is called the optic chiasm.

19. Phase Four: In the Brain Goes to the Visual Cortex located in the Occipital Lobe of the Cerebral Cortex. Feature Detectors. Parallel Processing We have specific cells that see the lines, motion, curves and other features of this turkey. These cells are called feature detectors.

20. Color Vision Two Major Theories

21. Trichromatic Theory Three types of cones: Red Blue Green These three types of cones can make millions of combinations of colors. Does not explain afterimages or color blindness well.

22. Opponent-Process theory The sensory receptors come in pairs. Red/Green Yellow/Blue Black/White If one color is stimulated, the other is inhibited.

23. Afterimages

24. Hearing Our auditory sense

25. We hear sound WAVES The height of the wave gives us the amplitude of the sound. The frequency of the wave gives us the pitch if the sound.

26. The Ear

27. Transduction in the ear Sound waves hit the eardrum then anvil then hammer then stirrup then oval window. Everything is just vibrating. Then the cochlea vibrates. The cochlea is lined with mucus called basilar membrane. In basilar membrane there are hair cells. When hair cells vibrate they turn vibrations into neural impulses which are called organ of Corti. Sent then to thalamus up auditory nerve.

28. Pitch Theories Place Theory and Frequency Theory

29. Place Theory Different hairs vibrate in the cochlea when they different pitches. So some hairs vibrate when they hear high and other vibrate when they hear low pitches.

30. Frequency Theory All the hairs vibrate but at different speeds.

31. Deafness Conduction Deafness Something goes wrong with the sound and the vibration on the way to the cochlea. You can replace the bones or get a hearing aid to help. Nerve (sensorineural) Deafness The hair cells in the cochlea get damaged. Loud noises can cause this type of deafness. NO WAY to replace the hairs. Cochlea implant is possible.

32. Touch Receptors located in our skin. Gate Control Theory of Pain

33. Taste We have bumps on our tongue called papillae. Taste buds are located on the papillae (they are actually all over the mouth). Sweet, salty, sour and bitter.

34. Vestibular Sense Tells us where our body is oriented in space. Our sense of balance. Located in our semicircular canals in our ears.

35. Kinesthetic Sense Tells us where our body parts are. Receptors located in our muscles and joints. Without the kinesthetic sense you could touch the button to make copies of your buttocks.