1. Sensation and Perception
Psych 1
Chapter 4

2. Sensory processes
Processing, interpreting, and organizing the information our senses take in
Sensation- receiving info from the environment through our 5 senses
Perception- interpreting the info that is received and making it meaningful
Sensation- sensory strip
Perception- parietal lobe

3. Absolute threshold
The level of sensory stimulation necessary for sensation to occur 50% of the time
Absolute threshold tested for each of the 5 senses

4. Absolute threshold examples
Vision- candle light seen at 30 miles away on a clear night
Hearing- tick of a watch under quiet conditions at 20 feet away
Touch- bee’s wing falling on your cheek from 1 cm above
Smell- 1 drop of perfume diffused in a 3 bedroom apartment
Taste- 1 teaspoon of sugar in 2 gallons of water

5. Difference thresholds
Also- Just Noticeable Difference
The minimum amount of difference (or change) in stimulation we can detect 50% of the time
There are difference thresholds for each of the 5 senses
Not predetermined like the absolute thresholds
Vary for each person
Difference thresholds are about the change in the proportion of the difference, not the change in the amount

6. Adaptation
Our unconscious process of ignoring unimportant sensory info
Allows us to deal with environments containing large amounts of stimuli
Without adaptation we would be continuously distracted and unfocused
Also- sensory adaptation/habituation

7. Selective attention
The focusing of conscious awareness on a particular stimulus
Can you feel your shoes? Watch? Earrings?
Cocktail party effect
Driving experiments

9. Inattentional blindness
Failure to see visible objects when our attention is directed elsewhere
Gorilla/basketball experiment

11. Change blindness Failing to notice changes in the environment
Speed date experiment from Dateline
Giving directions experiment

12. Your assignment!!! Complete the sensory processes worksheet
For difference threshold, develop your own examples of when you think you would notice a difference for each of the 5 senses
On the back, create a comic strip in which your characters display inattentional blindness and change blindness
4 squares each (4- inattentional, 4- change)
Dialogue or captions that explain why this is an example of each
Color

13. Perceptual constancies
5 areas of perception our mind does not change, we hold them steady to keep order and make sense of the world

14. Perceptual constancies
Size- ability to retain the size of an object no matter where it is located
Ex: Cars are not smaller because they are farther away from you
Color/brightness- the ability to see objects as the same color or brightness no matter the environment
Ex: Grass looks darker at night but we know it is the same color

15. Perceptual constancies
Shape- the ability to perceive an object as having the same shape regardless of at which angle we are viewing it
Ex: a door- whether open or close we know it is the same shape even though it looks different
Space- the ability to keep objects in the environment steady by perceiving either ourselves or the object as moving
Ex: driving in a car- focus on you moving or the outside moving, not both

16. Depth perception
Each eye sends a slightly different message to the brain (think split brain patients)
This difference is called retinal disparity
Allows us to see depth
Visual cliff and babies- proves we have depth perception early in life

18. Perceptual organization
Our ability to view pieces of information into an organized whole

26. Optical Illusions An inaccurate perception Famous types of illusions:
Muller-Lyer illusion:
Reversible figure:

28. Extra sensory perception
Beyond the normal level of awareness
A “feeling” something is wrong or familiar
Lack of scientific knowledge to prove ESP exists
Only information we have is from those who feel they have ESP- not a valid source

29. Types of ESP
Mental telepathy- communication through thoughts from one brain to another
Clairvoyance- seeing in the distance
Precognition- predicting the future
Psychokinesis- ability to move or alter an object by thought alone

30. The 5 senses Vision Hearing (audition) Touch (cutaneous senses)
Smell (olfaction)
Taste

31. Vision
Dominate human sense- we believe what we see first, our other senses are secondary
Depends on energy- light waves

32. Major parts of the eye
Cornea- outer covering

33. Major parts of the eye
Iris- colored muscle, regulates amount of light let in
Pupil- opening

34. Major parts of the eye
Lens- focuses the image onto the retina

35. Major parts of the eye
Nearsightedness and farsightedness

36. Major parts of the eye
Retina- back of the eye, contains light receptors
Fovea
Red eye?

37. Major parts of the eye
Optic nerve- bundle of cells, carries message from eye to brain
Where do the messages get sent to in the brain??

38. Major parts of the eye

39. Major parts of the eye Rods- night vision, sees black and white
Cones- day vision, sees color
Both located on the retina

40. Color vision All colors we see are a mix of red, green, and blue
Defects-
Color blind- see only certain color ranges
May struggle with shades of red, or shades of blue, or shades of green
8% males, 5% females
True color blind- can’t see color at all, only the rods are working, very sensitive to light

41. After images
When we focus on an image, the chemicals in our cones are used
When we look away, the unused chemicals are released to restore balance in the cones
This causes an after image of opposite colors

42. After images

44. Hearing Depends on energy, sound waves
Auditory nerve carries messages of sound into the brain

45. 4 characteristics of sound:
1. pitch- how high or low a sound is
2. timbre (TAM-ber)- the complexity of a sound
Variations, flute vs. piano
3. intensity- the loudness of a sound
4. decibels- measures intensity

46. Touch- cutaneous senses
We have 3 types of nerve receptors in our skin that each send messages into the brain

47. Touch- cutaneous senses
1. pressure-
bruise, bug crawling, pinprick
2. temperature-
registers changes in temperature of your surroundings
3. pain-
Remains active continuously to record injuries or poison
Will continue to send pain messages to brain until injury is gone

49. Smell Most animal like sense
Olfactory bulbs- carry messages of smell to the brain
When odors are associated with an emotion or event, we never forget
If we smell the odor again the memories come back
Sense of smell is connected to the limbic system
Hippocampus forms memories
Amygdala controls emotional response

50. Taste
Taste receptors- chemical receptors on the tongue, decode molecules of food or drink to identify them
Salty
Sweet
Sour
Bitter
Umami (new research)

52. Sensation Stations
Meet with your group to work on the worksheet for your station
You will need:
To include a name for your station at the top (related to your sense)
To print copes and have them here the start of the hour Wednesday (35 students- minus your group)
To make sure the worksheet requires students write/answer/fill out something for both activities at your station
To make sure the worksheet has instructions and will be self-explanatory for students at your station