1. Sensation and Perception
Chapter 4
Sensation and Perception

2. Sensation and Perception:
Section 1
Sensation and Perception:
The Basics

3. Sensation
The stimulation of sensory receptors and the transmission of sensory information to the central nervous system
Brain and spinal cord
Sensory receptors are located in the eyes, ears and elsewhere in the body.
The stimulation of the senses is automatic

4. Perception Process through which we interpret sensory simulation.
Reflects learning, expectations and attitudes.

5. Stimulation of the senses and the ways in which people interpret that stimulation is effected by concepts
Absolute threshold
Difference threshold
Signal detection theory
Sensory adaptation

6. Absolute Threshold The weakest amount of a stimulus that can be sense.
Some people are more sensitive than other
Hearing test
The first sound you can hear

7. Difference Threshold
Low enough so we can see, hear, smell, taste, and feel
But not too low to overload us with information
The minimum amount of difference that can be detected between 2 stimuli
Paint chips
Dark-dark
Dark-a little lighter

8. Signal Detection Theory
A method of distinguishing sensory stimuli that takes into account not only their strengths but also:
Setting
Your physical state
Your mood
Your attitudes
Also considers psychological factors such as:
Motivations
Expectations
Learning
We focus on what we deem important.

9. We focus on what we consider important

10. Sensory Adaptation
The process by which we become more sensitive to real stimuli and less sensitive to unchanged stimuli
Low light in a theater
Noise of the city

11. Section 2
Vision

12. “Seeing is believing”
Why do we put so much more trust in evidence that we have seen than evidence we have heard?

13. The eye Very similar to a camera
The amount of light entering the eye determines the size of the pupil.
Very similar to a camera
The amount of light entering the eye determines the size of the pupil.

14. Lens Retina
Adjusts to the distance of objects by changing its thickness
When you squint, you’re adjusting the thickness.
The sensitive surface in the eye that acts like film in a camera
Photoreceptors
Neurons that are sensitive to light
Carry visual input to the brain

15. 2 type kinds of photoreceptors
Cones
Allow you to see in color
Blind Spot
The Point where the optic nerve leaves they eye. We would never be able to “see” without it.
Rods
Sensitive to brightness of light
Allow you to see in black and white

16. Adaptation Dark light Walk into a dark room too dark to find a seat
Starts to adjust to lower light
Will continue for 45 minutes
Walking into a bright room
A first blink/ hurts
Within a minute you can see
Adaptation to light happens a lot faster

17. Visual acuity
Determined by the ability to see visual details in normal light
Nearsighted
Can not see details farther away
Farsighted
Can not see details close up

18. Color Vision Afterimages
Complementary color of the original color. Staring at one will create an afterimage of another

19. Color Vision Color blindness
Partially or totally unable to distinguish color due to the absence of or malfunction in the cones
Color Vision

20. Optical Illusions
Mona Lisa

21. Section 3
Hearing

22. Hearing
Sound is caused by the changes in air pressure that result from vibration.
Each vibration is called a cycle or a sound wave.
Every wave has it’s own pitch and loudness.

24. Pitch
Pitch of a sound
How low and high the sound is depends on its frequency or the # of cycle per second
More cycles the higher the sound
Women- short
Higher voices
Men- long
Lower voices

25. Loudness is determined by the amplitude of sound waves
Is measured by decibels

26. Deafness Conductive Sensorineural
Occurs because of damage to the middle ear (hearing aids)
Sensorineural
Damage to the inner ear
Concerts---jobs

27. Can you hear this

28. Help of the Deaf Sign Language Implants Sign language
Closed captioned shows
Use of light as
alter devices
Sign Language

29. Would You Rather?
Lose your eyesight or hearing?
WHY?

30. Section 4
Other senses

31. Do you have food cravings?

32. Do you have food cravings?
Research suggest women are more likely to crave sweet foods with lots of fat such as chocolate.
Men are prone to crave foods high in protein and fat, such as burgers and lasagna.
Do you think food cravings are influenced by societal standards?

33. Chemical senses Taste Smell Dogs taste sweetness cats can not.
Dogs have 7 times stronger sense of smell than humans
Without it could not taste as much.
Olfactory Nerve
Adapts quickly
Locker room
Perfume
Smoke
Harmful fumes
Taste
Dogs taste sweetness cats can not.
4 basic qualities
Sweetness
Saltiness
Sourness
bitterness

34. The Taste Buds
Bitter
Sour
Sweet
Salty

35. The Skin Senses Pressure Temperature
Sensory receptors fire when the skin is touched
Fingertips, lips, nose and cheeks are more sensitive
Shoulders, thighs and calves less sensitive.
Is relative
Neurons just beneath the skin
Adapt to difference in temperature
Pool water
Going out into heat from an air conditioned building

36. Pain Gate theory Phantom limb pain
A certain amount of information can be processed at a time. Rubbing/ scratching interrupts the pain message
Phantom limb pain
Pain in missing limbs
Stored memories of missing limb

37. Pain

38. Video
Helen Keller

39. Section 5
Perception-
The way we organize or make sense of our sensory impressions

40. Closure
Tendency to perceive a complete or whole figure even when there are gaps in what your sense tell you.

41. Figure ground perception
Is the perception of figures against a background.
Look out a window
People, dogs, cars, trees, houses on a background

42. Proximity

43. A presentation showing slide examples of the Gestalt Theory's principle of Proximity in different mediums of advertising, art and photography.
Gestalt Theory Principle: Proximity

44. Similarity- people think of similar objects belonging together.

45. The rule of Continuity
The perceptual tendency to group stimuli into continuous patterns.
People prefer to see smooth continuous patterns not disrupted ones.

46. Common Fate
Things moving in the same direction are perceived as belonging together.
Example: Group of runners people running together in the same direction would appear to have the same purpose.

47. Visual Illusions
Illusions