Are You Highly Sensitive?
A Self- test.
Read and answer survey questions
Add your total
range between 27-189
100+ = sensitive
Unit 5:
Sensation and Perception
Objective 1:
What are sensation & perception?
• Sensation
– the process by which our sensory receptors and
nervous system receive and represent stimulus
energies from our environment
• Perception
– process of organizing and interpreting sensory
information, enabling us to recognize meaningful
objects and events
• One continuous process
Prosopagnosia
http://www.youtube.com/watch?v=dxqsBk7Wn-Y
Objective 2:
What three steps are basic to all our
sensory systems?
1. receive sensory information
2. transform that stimulation into neural impulses
3. deliver the neural information to your brain
TRANSDUCTION –
the process of converting one form of energy into
another form that your brain can use
Objective 3:
What are absolute & difference thresholds? What
is Weber’s Law?
 Absolute threshold
the minimum stimulation
necessary to detect a
particular stimulus 50% of the
time.
Thresholds
Difference Thresholds
 Difference threshold
 Just noticeable difference (jnd)
 Smallest difference between 2 stimuli which a subject can
detect at least 50% of the time
The detectable
difference increases w/
the size of the stimulus
Weber’s Law
 Two stimuli must differ by a constant proportion not a
constant amount for a difference to be detected
 The louder the sound is, the brighter a light is, the more you
would have to change it, proportionally, to notice a
difference
If the just-noticeable difference (jnd) for a 10 ounce weight is
1 ounce, the jnd for an 80 ounce weight would be _____
ounces
a. 1
b. 2
c. 4
d. 8
e. 10
Joey’s bag of marbles is twice as heavy as Luke’s. If it takes 5
extra marbles to make Luke’s bag feel heavier, it will take 10
extra marbles to make Joey’s bag feel heavier. This best
illustrates
a. absolute threshold
b. sensory adaptation
c. Weber’s Law
2 stimuli must differ by a constant proportion for
their difference to be perceived
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
Just noticeable difference
If an adult develops cataracts, his or her
A. absolute threshold for light is likely to increase.
B. difference threshold for light is likely to decrease.
C. absolute threshold for light is likely to decrease.
D. difference threshold for light is likely to remain
unchanged.
E. Absolute threshold for light is likely to remain the
same.
Some people are better than others at
detecting slight variations in the tastes of
various blends of coffee. This best illustrates
the importance of
A. Absolute threshold
B. Difference threshold
C. Subliminal stimulation
You are going to briefly look at a picture then answer some
questions. DO NOT DWELL ON THE PICTURE. Look at it
long enough to “take it all in” once. After this, you will
answer a series of yes/no questions.
HEADS DOWN – CLOSE EYES
Circus act - training a seal
Costume Ball - Dancing
Raise
Your
Hand
for
a
“Yes”
Answer
In the picture, was there:
 an automobile?
 a man?
 a woman?
 a child?
 an animal?
 a whip?
 a sword?
 a man’s hat?
 a ball?
 a fish?
…Objective 3…
 Subliminal
 Under awareness
 Prime
 To be made aware of a stimulus
 to “get ready” for a stimulus
 activates unconscious awareness
Objective 4:
 Subliminal Persuasion
Messages under our awareness that
get you to alter your behavior
Another One Bites The Dust
http://www.youtube.com/watch?v=7MMMjLDdH-A
Objective 5
What function does sensory adaptation
serve?
 Sensory adaptation
 Reduced sensitivity to a repeated stimulus
 Helps us notice new stimuli in our environment
 Keeps our senses from getting fatigued
Perceptual Set
A mental predisposition to perceive
one thing and not the other
Brain Games: Seeing Isn’t Believing
http://www.youtube.com/watch?v=UyGkMhWE194
Objective 6
 Perceptual Set can effect what we see
 Perceptual set can effect what we hear
http://www.youtube.com/watch?v=G-lN8vWm3m0
 Context Effects
 Culture
 perspective