Sensation and
Perception
Preassement to
Sensation and
Perception
Question 1
You
can see color in your
peripheral vision
FALSE
Question 2

Receptor cells allow you
interpret what is going on
your world
TRUE
Question 3
Sensation
refers to the
process of getting information
from the world to our brain.
TRUE
Question 4

If you stay in a hot tub it
will seem as hot as it did
when you first got in it.
Sensory adaptation refers
to the decline in sensitivity
to a constant stimuli.
FALSE
Question 5
Our
interpretations of the world
are due to our personal
sensations.
FALSE
Question 6
The
colored part of the eye,
which is actually a ring of
muscles that controls the size
of the pupil, is called the iris
TRUE
Question 7
The
eardrum is interprets
sound waves for the brain so
that we can hear.
FALSE
Question 8
People
judge people based on
what groups they belong
TRUE
Question 9
On
a clear, dark night we can
see a candle flame 30 miles
away.
TRUE
Question 10
Advertisers
are able to
shape our buying habits
through subliminal
messages
FALSE
Question 11
If
we stare at a green
square for a while and then
look at a white sheet of
paper, we can see red
TRUE
Question 12
If
we close our eyes and
hold our nose, we cannot
taste the difference between
an apple and a raw potato.
TRUE
Question 13
If
required to look through a
pair of glasses that turns the
world upside down, we soon
adapt and coordinate our
movements without
difficulty.
TRUE
Question 14
If
people are told that an
infant is “David”, they are
likely to see “him” as bigger
and stronger that if the
same infant is called
“Diana.”
TRUE
Question 15
Laboratory
evidence clearly
indicates that some people
do have ESP
FALSE
Our Essential Questions! 
 How
do sensations and perceptions differ?
 How do the senses transform information
into brain messages?
 What is the nature of attention?
Grab a scrap sheet of paper
Write
down your definition of
sensation
perception
Let’s brainstorm…
 Sensation
Perception
Sensation
 The
process by which our
sensory systems (eyes,
ears, and other sensory
organs) and nervous
system receive stimuli
from the environment
 A person’s awareness of
the world
Perception
The
process of integrating,
organizing and interpreting
sensations.
Bottom-Up Processing
 Information
processing that
focuses on the
raw material
entering through
the eyes, ears,
and other organs
of sensation
Top-Down Processing
 Top-Down

Processing:
expectations and experiences influence how
we interpret incoming sensory information
Sensation v Perception
 Complete
the worksheet
The Major Senses
7







major senses
Vision (most studied)
Hearing
Touch
Smell
Taste
Vestibular
Kinesthetic
 http://www.youtube.com/watch?v=YuYrPB
2i-_8

The Riddle of Separate
Sensations
Sense receptors
 specialized cells
unique to each
sense organ that
respond to a
particular form of
sensory
stimulation
Sensory Receptors – An
Example
 When
you bite into a crisp
apple, you hear the
crunch, you taste the
sweetness, you feel the
smooth skin, you see the
red, and you smell the
aroma.
Receptor Cells
 Each
of the seven
senses is specifically
coded to only take in
one type of stimulus,
whether it be light
waves, sound waves,
smell, taste, or touch.
What Does That Mean?
Turn
to your neighbor
and tell them what
sensation means.
What is with those
blasted receptor cells
as well… explain
what they do
Principles of Sensation
 Transduction
 Absolute
threshold
 Difference threshold
 Sensory adaptation
Transduction
 The
process by
which a form of
physical energy is
converted into a
coded neural
signal that can be
processed by the
nervous system.
What is a
Threshold?
Threshold
 An
edge or a boundary
 Walking into the room – on one side
you are in the room on the other you
are outside of the room
Absolute Threshold
The
smallest possible
strength of a stimulus that
can be detected half the
time.
Absolute Threshold Example (1)
 Taste:
1 gram of table salt in 500
liters of water – the minimum
needed to taste something
Absolute Threshold (2)
 Vision:
A candle flame on a
clear night, 30 miles away –
the minimum needed to
see it. Doesn’t mean that
you can make out what it is
Just Noticeable Difference Threshold
The
minimum difference that a
person can detect between two
stimuli 50% of the time.
Examples
 When
you can detect the difference
in volume of music
 When you can detect the difference
in pressure on your arm
Weber’s Law
 The
greater the magnitude of the
stimulus, the larger the
difference must be in order to be
noticed
Weber’s Law Example
 If
you are carrying 20 lbs. and add 5
lbs., it’s noticeable. If you are
carrying 100 pounds and add 5
pounds, it may not be noticeable.
You need to add 10 lbs. to 100
pounds to make it noticeable.
Weber’s Law Lab
In groups of 3, follow the
directions and complete the lab
Sensory Adaptation
When
exposed to a stimuli over
a period of time there will be a
diminished sensitivity to it
If a stimulus is constant and
unchanging, eventually a person
may fail to respond to it
Example of Sensory Adaptation
hot tub – after a certain period
of time no longer seems as hot
A
The Nature of Attention
 Where
here?
does attention come into play
Hypothetical Situation
 What
would happen if we had no filter
between sensation and perception?”
 Hallway example
Sensory Overload
 Overstimulation
of the senses
Selective hearing
Do
you think it exists?
Selective Attention
 Focusing
conscious awareness on a
particular stimulus (sense) to the
exclusion of others
Selective Attention Examples
 Walking
down the
hallway – all
5 senses are
firing. What
grabs your
attention?
Let’s write!
 How
do sensations and perceptions differ?
 How do the senses transform information
into brain messages?
 What is attention? How much control do
we have over our attention?
Time to get creative!
 With
your partner, create a poster
depicting 3 the following:





Sensation
Perception
Attention
Absolute sensory thresholds
Sensory overload
 http://www.youtube.com/watch?v=lN4m0t4
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