1. Sensation & Perception

2. The Lion King

4. Do you see the message hidden?

5. Do you see the message hidden?

7. Political Subliminal Message
What impact does this message have?
Will it last?
Commercial

8. Subliminal Messages Hidden messages targeted at our subconscious mind.
Examples:
1. Small images inside a larger picture
2. An audio message hidden inside a recording
3. Messages in song played backward
4. Hidden words or pictures that quickly appear
5. Powerful marketing tools
Effects us on a emotional level
Short lived results

9. Sensation & Perception
Sensation- stimulation of the sense organs
Raw data of experience: smells, sights, sounds, pain, etc.
Perception- creating meaning from the raw sensory information

10. Basic Process
Sensory organs absorb energy from a physical stimulus in the environment
Sensory receptor cells detect stimulus energies and convert them into neural impulses (transduction)
Electrochemical message is sent to the brain
Specific areas of the brain organizes the input and transforms them into something meaningful

11. Attention
Selective Attention- focusing our awareness on a particular stimuli
Cocktail Party Phenomenon- filter out many sounds to maintain one conversation but will notice your name in another conversation

12. Psychophysics- how physical stimuli are translated into psychological experience
Gustav Fechner’s work on thresholds
Threshold- is a dividing point between energy levels that do and do not have a detectable effect
Absolute Threshold- minimum amount of stimulation that an organism can detect 50% of the time
Environment can affect detection of a stimulus
Examples of absolute threshold under ideal conditions
Online demo:

13. JND- just noticeable difference is the smallest difference in the amount of stimulation that a specific sense can detect
The absolute threshold is the jnd from nothing (no stimulus)
JND is greater for stronger stimuli than for weaker ones
As a stimulus increases in magnitude, the JND becomes larger

14. Weber’s Law- states that the size of a jnd is a constant proportion of the size of the initial stimulus
This portion is called the Weber Fraction
It can apply to all the senses but different fractions apply to different types of sensory input
Ex: Weber fraction for weights is 1/30, which means you should detect the difference btw a 30 ounce weight and a 31 ounce weight
Envelope/Book EXPERIMENT!

15. Fechner’s Law
The magnitude of a sensory experience is proportional to the # of JNDs that the stimulus causing the experience is above the absolute threshold.
Constant increments in stimulus intensity produce smaller and smaller increases in perceived magnitude of sensation.
EX: Dark room with lamp and three bulbs.
Three equal increases in stimulus intensity produce progressively smaller differences in the magnitude of sensation.

16. Imagine you are monitoring a radar screen

17. Signal Detection Theory
The detection of stimuli involves decision processes as well as sensory processes, which are influenced by many factors besides stimulus intensity
Radar Screen with four possible outcomes:
Hits-Detecting signals when present
Misses-Failing to detect signals when present
False Alarms-detecting signals when they are absent
Correct Rejection-Not detecting signals when they are absent

18. Setting Criterion
Depends on our expectations and on the consequences of missing a signal or of reporting a false alarm.
Ex: Waiting for the pizza guy at a party.

19. Sensory Adaptation
Gradual decline in sensitivity to prolonged stimulation
Ex: Garbage
In reality, the stimulus intensity (the odor) stays the same but with continued exposure your sensitivity to it decreases
Ex: Jumping into a swimming pool
It allows people to ignore the obvious but you can notice CHANGES in sensory input
A behavioral adaptation that has been sculpted by natural selection