Unit 4 Sensation and Perception Lecture
List the 5 senses below:
Perception is important because:


It is the key mediator between
______________________________________________
It is the source of most knowledge that humans acquire
Definitions
Sensation
Define below:
Perception
Define below:

enables us to recognize meaningful objects and events
Sensation
Bottom-Up Processing
 Information processing beginning “at the bottom” with raw sensory data
that are sent “up” to the brain for higher level analysis
 _________________________ processing that moves from the parts to
the whole
Give an example:
Top-Down Processing
 Information processing starting “at the top” with higher level cognitive
processes (such as expectations and knowledge) and then “working
down”
 ________________________________ processing that moves from the
whole to the parts
Give an example:
Sensation- Basic Principals
Psychophysics
 study of the relationship between physical characteristics of stimuli and
our psychological experience of them
 Light: ________________________
 Sound: _______________________
 Pressure: _____________________
 Taste: ________________________
Sensation- Thresholds
Absolute Threshold
 ____________________________ needed to detect a particular stimulus
 usually defined as the stimulus needed for detection ________ of the time
Give an example:
Difference Threshold
 minimum ___________________________________ that a subject can
detect 50% of the time
 just noticeable difference (JND)
 increases with magnitude
Give an example:
Signal Detection Theory
 predicts how and when we detect the presence of a faint ____________
(signal) amid background _______________ (noise)
 assumes that there is
__________________________________________
 detection depends partly on person’s
-experience
-motivation
-expectations
-level of fatigue
Weber’s Law________________________________________________________________
________________________________________________________________
 light intensity- 8%
 weight- 2%
 tone frequency- 0.3%
Sensory Adaptation: diminished ______________________________________
- receptors higher up in sensory system get tired and fire less frequently
Examples:
Vision
Transduction: _____________________________________________________
Wavelength: the distance from the peak of one wave to the peak of the next
Hue: dimension of color determined by __________________________
Intensity: amount of energy in a wave determined by amplitude
 __________________________
 __________________________
Vision: Physical Properties of Waves
Draw examples of the waves below:
Short wavelength=high
frequency
(bluish colors, high-pitched
Great amplitude
(bright colors, loud
sounds)
sounds)
Long wavelength=low frequency
(reddish colors, low-pitched
sounds)
Small amplitude
(dull colors, soft
sounds)
Vision: Parts of the Eye
________________-: transparent covering on the front of the eye
_____________: central point of focus on the back of the eye
_____________: adjustable opening in the center of the eye
_______: a ring of muscle the forms the colored portion of the eye around the
pupil and controls the size of the pupil opening
_________: transparent structure behind pupil that changes shape to focus
images on the retina
Accommodation: change in shape of lens focus near objects
__________________
 Layers of neurons on inner surface of eye
 light sensitive
 contains rods
and cones
 beginning of
visual
information
processing
Blind Spot: area of retina
where optic nerve leaves back
of eye
Retina’s Reaction to Light Receptors
Cones
–
near center of ___________________
–
_____________________________
–
daylight or well-lit conditions
Rods
•
Located in periphery of _______________
•
detect __________________________________________
•
twilight or low light
Vision
Acuity: _______________________________
Nearsightedness
 _______________ objects seen more _____________
 lens focuses image of distant objects in front of retina
Farsightedness
 _____________ objects seen more _____________
 lens focuses near objects behind retina
Color-Deficient Vision
People who suffer ________________ blindness have trouble perceiving the
number within the design
Visual Information Processing
Feature Detectors
 ____________________________________________________ to
specific features
 shape
 angle
 movement
Parallel Processing
 simultaneous processing of
__________________________________________________________
 color
 motion
 form
 depth
Visual Information Processing
_________________________________________________
 Young and Helmholtz
 The eye contains _____________ different types of cones capable of
responding to various _________________________
 red
 green
 blue
 Opponent-Process Theory:
___________________________________________________________
Draw a Necker Cube below:
Visual Perception: Gestalt
•
Gestalt Principles (gestalt = an organized whole. We tend to integrate pieces of
info. into meaningful wholes)
– _______________________
– _________________ (law of good form)
– _______________________________
– ________________________
– Continuity
– Similarity
– Phi Phenom
Visual Perception: Depth
Depth Perception: The Visual Cliff
 Binocular Cues:
___________________________________________________________
___________________________________________________________
 Retinal Disparity: the fact that the right and left eyes see slightly
different views of the object
 Convergence: the degree to which the two eyes must converge to
focus on the object
 Monocular Cues: _____________________________________________
 Linear Perspective: parallel lines converge in the distance
 Relative Size: if two objects are the same, the larger one is seen as
closer
 Interposition:
_____________________________________________________
_____________________________________________________
 Texture Gradient: textures are coarser the closer they are
 Light and shadow
 Height in plane
Visual Perception: Constancies
Perceptual Constancies:
________________________________________________________________
________________________________________________________________
 Color: an object will be perceived as the same color even if the color
reflected on the retina changes
Example:
 Size: an object will be perceived as the same size even if the size
reflected on the retina changes
Example:
 Shape: an object will be perceived as the same shape even if the shape
reflected on the retina changes
Example:
Audition (Hearing)
– Audition
– the sense of ______________________
– Frequency
– the _____________________________________ that pass a point in a given
time
– Pitch
– a tone’s ____________________________
– depends on frequency
– The Stimulus
– Vibrations of
______________________
– Amplitude: __________________
– Wavelength: pitch
– Purity: timbre
Audition: The Ear
Outer Ear
-
Auditory Canal
___________________________
Middle Ear
-
________________________
_________________________
stirrup
Inner Ear
-
oval window
cochlea
basilar membrane
_____________________________
Audition: Pitch Perception
Place Theory
 the theory that links the pitch we hear with the place where the cochlea’s
membrane is stimulated
Frequency Theory
 ___________________________________________________________
___________________________________________________________
How we locate sounds
 ________________________________________________
 Sound is heard in the nearest ear first
 Sound is heard loudest in the nearest ear
Audition: Loss
Conduction Hearing Loss
 hearing loss caused by _______________ to the mechanical system that
conducts _________________________________
Nerve Hearing Loss
 hearing loss caused by damage to the cochlea’s receptor cells or to the
auditory nerve
Touch
•
Skin Sensations
– _____________________
•
only skin sensation with identifiable receptors
– ______________________
– ______________________
– ______________________
•
Gate-Control Theory
– Theory that the spinal cord contains a neurological “____________” that
blocks pain signals or allows them to pass on to the brain
– “gate” opened by the activity of pain signals
____________________________________
– “gate” closed by activity in larger fibers or by
___________________________________
Taste
•
Taste Sensations (List below)
•
Sensory Interaction
– the principle that one sense may influence another
– as when the smell of food influences its taste
•
The Stimuli: ____________________________________________
•
•
The Anatomy: taste buds act as the receptors for taste (about every
______________________)
Perception of taste & flavor
– Numerous factors can impact the flavor of food (Ex: temperature of the
food, texture, prior condition of the mouth, health state of the organism,
smell)
Smell (Olfaction)
•
•
•
•
The Stimuli: chemical substances that are soluble
The Anatomy: receptors are olfactory cilia which
______________________________________ and sinus
Sense ______________________ get filtered by thalamus
_____________________________ interact to produce _______________
Body Position and Movement
•
•
Kinesthesis
o the system for sensing the
______________________________________ of individual body parts
Vestibular Sense
o the sense of body movement and body’s position relative to gravity
o including the _________________________________
o Semicircular canals in ears
Touch
•
Numerous types of receptors lie in varying depths in the skin
•
Four Basic Skin Senses (List Below)