1. SENSATION

2. CHARACTERISTICS OF SENSES
TRANSDUCTION
•The process in which a sense organ changes
physical energy into electrical signals
•These signals become neural impulses which
are sent to the brain for processing

3. ADAPTATION
• The decreasing response of the
sense organs, the more they are
exposed to a continuous level
of stimulation
SENSATIONS VS PERCEPTIONS
• Sensations are meaningless bits of
information that result when the brain
processes electrical signal coming from
sense organs
• Perceptions are meaningful sensory
experiences resulting from the combination
of sensations

4. THE EYE
The eye is stimulated by Light waves
The visibility of these light waves depends in its
length in the Electromagnetic Spectrum
• SHORT WAVELENGTHS: INVISIBLE
• JUST RIGHT WAVELENGTHS: VISIBLE
• LONG WAVELENGTHS: INVISIBLE

6. No, not this eye.

8. Step 2:Eye gathers
Step 1: Light is this broad light
scattered around. andnarrow beam
passes through the
Cornea
Step 3: The Pupil
allows light to enter Step 4: Lens which
the eye while the Iris bends and narrows the
regulates the amount light waves
of light
Step 5: Light waves
reach the RETINA,
the transduction
begins.

9. >2nd Layer: The Middle
>1st Layer: The Back Layer
Layer Ganglion cells >3rd Layer: The Front
photoreceptors -chemical breakdown Layer
Rods- Rhodopsin. dim from the rods and cones Contains the optic
light, black, white and generate tiny electrical nerve fibers that brings
shades of gray force that if large the nerve impulses to the
enough, triggers nerve brain.
Cones- Opsin, bright light, impulses in the
colors and fine details neighboring ganglion
cells

11. Step 1: Thalamus does initial
processing of impulses then
passes it to the Occipital
Lobe
Step 2: Primary Visual Cortex
transforms nerve impulses to
simple visual sensations
Step 3: the Visual Association
Areas assembles all of the
basic sensations.

12. Color Vision
Two Theories:
• TRICHROMATIC THEORY
- there are 3 cones in the retina containing
Opsin. These opsins are responsive to
different wavelengths that corresponds to the
primary colors red, blue and green.
• OPPONENT PROCESS THEORY
-ganglion cells in the retina and cells in the
thalamus respond to two pairs of colors; red-
green and blue-yellow. One color is for
excitement and the other is for inhibition.

13. THE EAR
AWESOME TERMS
•Sound waves - stimuli for hearing
•Loudness - your subjective experience of
a sound's intensity
- calculated through amplitude
•Pitch - your subjective experience of
a sound being high or low
- calculated through the
frequency of sound waves

15. • Decibel - unit to measure loudness
- our threshold for hearing ranges
from 0 dB (no sound) to 140 dB
(can produce pain and permanent
hearing loss)

16. THE EAR
• Outer Ear
o External Ear
- an oval-shaped structure that sticks out
from the side of the head
- picks up sound waves and sends them to
the auditory canal
o Auditory Canal
- long tube that funnels sound waves down
so that the waves strike a thin, taut
membrane--the eardrum

17. o Tympanic Membrane
- taut, thin structure commonly called the
eardrum
- vibrates when sound waves strike
- passes the vibrations to the first small bone
attached to it

18. • Middle Ear
- a bony cavity that is sealed at each ends by
membranes
- the three tiny bones are collectively called
ossicles, and because of their shapes, they
are referred to as the hammer, anvil and
stirrup
- the ossicles act like levers that greatly
amplify the vibrations and cause the oval
window to vibrate as well

19. • Inner Ear - contains the cochlea and the
vestibular system
Cochlea - bony coiled exterior shaped like a
snail's shell (like a straw wound up)
 Oval Window
- vibrates the fluid in the cochlea's tubes
where the auditory receptors are located
 Auditory Receptors (hair cells)
- the mechanical bending of the hair cells
generates miniature electrical forces that, if
large enough, trigger nerve impulses
 Auditory Nerve
- carry nerve impulses to the brain

21. VESTIBULAR SYSTEM
-part of the inner ear, located above the
cochlea
-It includes three semicircular canals that
contains fluids that react to the movements of
the head
-In the canals are the sensory hair cells
that responds to the movements of the fluid.

23. >What causes motion sickness?
-sensory mismatch between the information of
the vestibular system and the movement of
your head.
-has symptoms like dizziness and nausea
>What causes Meniere’s disease and
vertigo?
-malfunction of the semicircular canals of the
vestibular system.
-has symptoms like dizziness, nausea, vomiting,
spinning and head splitting buzzing sounds.

24. TASTE
• called a chemical sense because stimuli are
various chemicals
THE TONGUE
• the tongue has four basic tastes areas:
sweet, salty, sour and bitter
• surface has small narrow trenches where
the chemicals (the stimuli) go
• taste buds in the trenches produce nerve
impulses that are sent to the brain which
are transformed into sensations of taste

26. How can we tell the difference between two
kinds of sweet?
FLAVOR
• combined sensation of taste and smell

27. SMELL (Olfaction)
• chemical sense because its stimuli are
various chemicals that are carried by air
How do we smell?
1. Stimulus (ex. skunk spray, eww) reach the
olfactory cells in the nose (receptors for
smell)
2. Skunk spray molecules dissolve in the
mucus (thick gluey film covering the
olfactory cells) and trigger nerve impulses

28. 2. d
3. Nerve impulses travel to the olfactory
bulb above the olfactory cells.
4. Impulses are relayed to the primary
olfactory cortex where they are
transformed into the olfactory sensations of
a skunk spray.

29. Functions of Olfaction
• Intensifies the taste in foods
• Warns us of potentially dangerous foods
• Smell elicits strong memories associated
with emotional feelings

30. TOUCH
The sense of touch includes pressure,
temperature and pain.
Beneath the outer layer of the skin are
half-dozen miniature sensors that are
receptors for the sense of touch. These
receptors changes mechanical pressure of
changes in temperature into nerve impulses
to be sent to the brain.

31. Receptors in the Skin
• The skin has the outer layer that contains no
receptors. Underneath that thin layer has the
first receptors that are threadlike extensions
in form .The middle and fatty layer has
receptors varying in shapes and functions.
• Free nerve endings are wrapped around the
base of each hair follicle called hair
receptors. They respond to the movement of
our hair.

32. • The free nerve endings transmit the
responses of the hair follicles as pressure
and pain.
• The receptor called Pacinian Corpsucle is
found in the fatty layers of the skin. It looks
like an onion bulb and is highly sensitive to
touch. It responds to vibrations.

33. Brain Areas
All these receptors in the skin send their
signals to the brain through the spinal cord
then to the somatosensory cortex in the
parietal lobe of the brain. The cortex
transforms the impulses into basic sensations
of touch, pressure, pain and temperature.

34. PAIN
• Unpleasant sensory and emotional
experience that may result from tissue
damage, one’s thoughts or beliefs, or
environmental stressors
• Essential for survival
• Could be acute or chronic
• It was usually thought of as resulting only
from tissue damage
• Involves social, psychological and emotional
factors

35. picturesssss

36. GATE CONTROL THEORY OF PAIN
• Nonpainful nerve impulses (shifting
attention) compete with pain impulses (ex.
Headache) in trying to reach the brain
• This competition creates a bottleneck, or
neural gate, that limits the number of
impulses that can be transmitted
• You may not notice pain from a headache
while thoroughly involved in some other
activity

37. No Pain,
YAY!
Nerve Impulses
GATE CLOSED
Pain Signals

38. Besides the effects of psychological factors,
our initial perception of pain from a serious
injury can be reduced by our brain’s own
endorphins.

39. ENDORPHINS
• Chemicals produced by the brain and
secreted in response to injury or severe
physical or psychological stress
• Similar to morphine
• Produced in situations that evoke great fear,
anxiety, stress or bodily injury

40. PERCEPTION

41. Becoming Aware of a Stimulus
THRESHOLD
• A dividing line between what has detectable
energy and what does not
• Determines when we first become aware of a
stimulus
• Absolute threshold – 50% chance of
detecting stimulus
• Subliminal stimulus – 0-49%

42. Absolute threshold
Subliminal stimulus
Increasing Intensity

43. Ernst Heinrich Weber
"Why is the music still loud? -_-" he wondered.
...and soon developed the concept of:
JUST NOTICEABLE DIFFERENCE
• the smallest increase or decrease in the
intensity of a stimulus that a person is able
to detect
2oz vs 3oz 40lbs vs 41lbs

44. WEBER'S LAW
• At lower intensities, small changes between
two stimuli can be detected as just noticeable
differences; however, at higher intensities,
only larger changes between two stimuli can
be detected as JNDs

45. SENSATION VS PERCEPTION
Basic Difference
• Sensation
- Our first awareness of some outside
stimuli
-meaningless bits of information
• Perception
-Experience we have after the brain
assembles the meaningless bits of
information.

46. SENSATIONS TO PERCEPTIONS
1. Stimulus - any change in the environment
and surrounding.
2. Transduction - the change of physical or
chemical energy to electrical signals.
3. Brain: Primary Areas - these transforms
impulses to basic sensations.
4. Brain: Association Areas - these assemble all
the bits of sensory information from the
Primary Areas to make meaningful images,
sounds, smell, taste or feel.

47. 5. Personalized Perceptions - varies on every
person. It does not mirror reality but rather
include our biases, emotions and memories
to reflect reality.

48. RULES OF ORGANIZATION
• began with the Structuralists vs. Gestalt
Psychologists debate
• specify how our brains combine and organize
individual pieces or elements into a
meaningful perception

49. FIGURE-GROUND
• we tend to automatically
distinguish between a figure
and a ground: the figure
(more detail) stands out
against the background
SIMILARITY
• we group together the
elements that appear similar

50. CLOSURE
•we tend to fill in any
missing parts of a figure
and see the figure as
complete
PROXIMITY
• we group together
objects that are
physically close to
one another

51. SIMPLICITY
• stimuli are organized in
the simplest way
possible.
CONTINUITY
• we tend to favor smooth or
continuous paths when
interpreting a series of
points or lines

52. PERCEPTUAL CONSTANCY
a. Size Constancy - the tendency to perceive
objects as remaining the same size even when
their images on the retina are constantly
growing or shrinking

54. b. Shape Constancy - the tendency to perceive
objects as remaining the same shape even
when their images on the retina are
constantly changing.

55. c. Brightness and Color Constancy
It is the tendency to perceive brightness and
color as still the same even though there were
changes in lighting.

56. DEPTH PERCEPTION
• the ability of your eye and brain to add a
third dimension, depth, to all visual
perceptions
• the cues for depth perception are divided
into two major classes: binocular (depends
on the movement of both eyes) and
monocular (produced by signals from one
eye, and arise from the way objects are
arranged)

57. Binocular Depth Cues
CONVERGENCE
• based on signals sent from muscles that turn
the eyes
• to focus on near or approaching objects,
these muscles turn the eyes inward, toward
the nose
• the brain uses the signals
sent by these muscles to
determine distance of the
object

58. RETINAL DISPARITY
• depends on the distance between the eyes
• because of their different positions, each eye
receives a slightly different image
• the distance between the right and left eyes'
images is the retinal disparity

59. Monocular Depth Cues
LINEAR PERSPECTIVE
• results as parallel lines come
together, or converge, in the
distance
RELATIVE SIZE
• results when we expect two
objects to be the same size
and they are not
• the larger will appear closer
than the smaller

60. INTERPOSITION
• comes into play when
objects overlap
• the overlapping object
appears closer than the
object that is overlapped
TEXTURE GRADIENT
• areas with sharp, detailed
texture are interpreted as
being closer than those with
less sharpness and poorer in
detail

61. ATMOSPHERIC PERSPECTIVE
• created by the presence of
dust, fog or clouds
• we perceive clearer objects
as being nearer than the
hazy or cloudy ones
MOTION PARALLAX
•based on the speed of
moving objects
•the larger will appear
closer than the smaller

62. ILLUSIONS
Strange Perceptions
Two Reasons why Our Perceptions are not
exact copies of Reality
1. Damage to Sensory Areas
2. Our perceptions are influenced by our
experiences

63. BUT... there's another reason:
ILLUSIONS!

64. Illusion is a perceptual experience in which you
perceive an image as being so strangely
distorted that, in reality, it cannot and does not
exist. It is created by manipulating perceptual
cues so that your brain can no longer interpret
space, size, and depth cues.
Impossible Figure - a perceptual experience in
which the drawing seems to defy basic
geometric laws.

67. Examples:
Moon Illusion - the moon appears to be huge
when it is near the horizon but appears really
small when it's high in the sky.

68. Ames Room
-named after its designer, Albert Ames. This
Illusion shows that perception can be distorted
by changing depth cues.

70. Ponzo Illusion

71. Muller-Lyer Illusion

72. Have a great day!