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

2. Sensation
Sensation – process of detecting a stimulus through sensory receptors and the nervous system.
Process of sensing our environment through taste, sight, sound, touch and smell
Example:
Hearing Mrs. Joseph speak, the sound waves travel to the ears. The hair on the cells in the cochlea help transmit the information to the brain
Prosopagnosia – face blindness
All sensation, no perception

3. Perception
Perception – process by which we select, organize, and interpret sensory information to recognize meaningful objects and events
Based on our prior experiences and expectations
Example:
Seeing letters on a page and interpreting them as our favorite passage in a novel

8. Bottoms-up Processing
Bottoms Up Processing (AKA - Feature analysis)
Begins with the sensory receptors and works its way up to the brain
Use the features of the object itself to process the information
Examples:
seeing the individual fruits in this picture
Hearing a voice speak about AP Psych

9. Top Down Processing
Top Down Processing - Processing information from the senses with higher level mental processes using our experiences and expectations
Using your background knowledge to fill in the gaps
Examples:
Seeing the face in the picture made up of fruit
I _ope yo_ get an 5 on t_ _ A _e_am
Negative expectations about the pain of childbirth can increase pain during the birthing process

10. Find the following hidden items:
Scissors
Banana
Screwdriver
Horn
Heart
fish
boat
Shoe
needle

11. Aoccdrnig to a rscheearch at an Elingsh uinervtisy, it deosn’t mttaer in what oredr the ltteers in a word are, th olny iprmoetnt tihng is that frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and youcan still raed it wouthit a porbelm. This is bcuseae we do not raed erveylteter by it slef but the word as a wlohe.

12. Selective Attention
Selective Attention - Ability to focus our conscious awareness on a particular stimulus
Example: Cell phone usage while driving a car

13. Selective Attention Example

14. The Stroop Effect
Stroop Effect – the difficulty attending to the color because of the interference with the meaning of the word

15. Cocktail-party phenomenon
cocktail party effect - ability to focus one's listening attention on a single talker among a mixture of conversations and background noises, ignoring other conversations.
Form of selective attention.
Example:
You are at the football game and are cheering for the Comets when you hear Ms. Short call your name

16. Create your own examples Pick two that you are having the most difficulty with and make your partner come up with a new example
Sensation
Perception
Bottoms-up processing
Tops-down processing
Selective Attention
Stroop Effect
Cocktail Party effect
No stinky examples!

17. Selective Inattention
Change Blindness/Inattentional Blindness - Falling to notice changes in the environment
Example: Eating your lunch in the cafeteria, when your friend switches your sandwich and you don’t notice
Choice Blindness - failure to notice a switch in a choice that is made
Example: Participants asked to pick between two photographed faces, when photographs are switched…
Change deafness – failure to notice a change in voices that are speaking
Example: Listening to Mrs. Joseph speak, failure to notice that Mrs. Harvey is now speaking

18. Pop Out Effect
Pop out – stimuli we don’t chose to attend to but they draw our eyes and demand our attention
Example: Picture on the left

19. Psychophysics
Psychophysics - Study of how physical stimuli are translated into psychological experience.
Psychologists use thresholds to measure these events
Example: Tracking a person’s eye movements jumping every .33 of a second

20. Thresholds
Threshold – the point at which sensory information is strong enough to be noticed
Absolute threshold – minimum stimulation needed to detect a stimulus (light, sound, pressure, taste or order) 50% of the time
Examples:
Light
A candle flame at 30 miles on a dark, clear night.
Sound
The tick of a mechanical watch under quiet conditions at 20 feet.
Taste
One teaspoon of sugar in two gallons of water.
Smell
One drop of perfume diffused into the entire volume of a three-bedroom apartment.
Touch
The wing of a bee falling on your cheek from a distance of one centimeter.

21. Absolute Threshold

22. Signal Detection Theory
Signal Detection Theory -Predicts how and when we detect a signal amid background noise
Assumes no absolute threshold
Detection depends partly on a person’s experience, expectations , motivation and alertness…people respond differently to same stimuli
Example: Enemy submarine,
Waiting for the Pizza man to come at a busy party

23. Subliminal Stimulation
Subliminal – below one’s absolute threshold for conscious awareness
Example:
Listening to tapes in your sleep to get you to lose weight
Priming – increased sensitivity to certain stimuli due to prior experience outside conscious awareness
Example: Seeing a picture of a mouse before viewing the picture on the left

24. Do Subliminal Messages work?
Based on studies, some people do respond to stimuli below the absolute threshold, under some circumstances.
People behave differently at different threshold levels
Priming can briefly influence preferences or perceptions
Complex behaviors are NOT influenced by subliminal messages
Some people are more suggestible than others
Placebo effect 25 50 75
100
Low
Absolute
threshold
Medium
Intensity of stimulus
Percentage
of correct
detections
Subliminal
stimuli

25. Think Pair Share
What is the difference between absolute threshold and signal detection theory?
You are conducting an experiment with participants who are listening to music that is gradually increased in volume. Describe a hit, miss, correct rejection, & false alarm for this scenario
According to signal detection theory, will the participant always raise their hand at the same volume level if the experiment is repeated?
What are priming and subliminal messaging?

26. Just noticeable difference

27. Just noticeable difference

28. Just noticeable difference

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30. Just noticeable difference

31. Just noticeable difference

32. Just noticeable difference

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35. Just noticeable difference

36. Just noticeable difference

37. Just noticeable difference

38. Just noticeable difference

39. Difference Threshold
Difference Threshold (AKA Just Noticeable Difference) – the amount a change needed in a stimulus (stronger or weaker) for us to recognize the change has occurred
the greater the intensity (ex., weight) of a stimulus, the greater the change needed to produce a noticeable change.
Example:
Some people are better at detecting slight variations in the taste of pop

40. Weber’s Law
Weber’s Law (Related to JND) - For people to really perceive a difference, the stimuli must differ by a constant "proportion" not a constant "amount".
Proportion varies depending on the stimulus

41. Weber’s Law JND Example:
Pitch = .003 ( if someone sings a little off key, we will be able to tell)
Loudness = .10
Saltiness = .20
Light = .08
Example:
JND for a 10oz weight = 1 oz. To notice a 50 oz weight would be 5oz
JND for a 10 decibel sound = .10 decibels . To notice a sound of 30 decibels would be _______?

42. Sensory Adaptation
Sensory Adaption - Diminished sensitivity as a consequence of constant stimulation
Example:
Jumping into a cold swimming pool, doesn’t feel cold after a while
Your eyes when you turn off the lights
Do you feel your underwear all day?