The Lion King
Do you see the message hidden?
Do you see the message hidden?
Political Subliminal Message
 What impact does this message have?
 Will it last?
 Commercial
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
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
Basic Process
1.
2.
3.
4.
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
Attention
 Selective
Attention-
focusing our
awareness on a
particular stimuli
 Cocktail Party
Phenomenonfilter out many
sounds to maintain
one conversation
but will notice your
name in another
conversation
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: http://www.garyfisk.com/anim/threshold.swf
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
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!
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.
Imagine you are monitoring a radar
screen
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:
A. Hits-Detecting signals when present
B. Misses-Failing to detect signals when present
C. False Alarms-detecting signals when they are absent
D. Correct Rejection-Not detecting signals when they are
absent
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.
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