Download Chapter 3: SENSORY PROCESSES

► Chapter 3: SENSORY PROCESSES ◄
SENSING AND PERCEIVING: A FEW BASIC CONCEPTS
A. Sensation: is the conversion of energy from the
environment into a pattern of responses by the nervous
system.
Perception: is making sense of that information (sensation)
B. Transducer: a mechanism that converts energy from one form
to another
Problem: neurons use only chemical & electrical energy
Outside World
Electromagnetic
Pressure
Chemicals
Chemicals
Mechanic
Sensory System
Vision
Audition
Gustation
Olfaction
Somatosensation
Sensation/Perception
Seeing
Hearing
Tasting
Smelling
Touch
Transduction
C. SENSORY THRESHOLDS AND ADAPTATION:
1. Psychophysics: The study of how physical stimuli are
translated into psychological (sensory) experiences
2. Absolute Thresholds: is the minimum amount of stimulation
that an organism can detect 50% of the time.
Exam 2 Notes -23. Difference Thresholds - Just Noticeable Difference (jnd):
is the smallest difference in the amount of stimulation
that a specific sense can detect
4. Signal Detection Theory:
A decision making process
5. Sensory Adaptation: Involves a gradual decline in
sensitivity to prolonged stimulation (you get use to it).
Dark Adaptation: eyes become MORE SENSITIVE to light in
low illumination.
• VISION •
THE EYE
A. STRUCTURES THAT FOCUS VISUAL IMAGES
1. Cornea: serves as protection for the structures behind it
2. Lens:
- Transparent eye structure
- FOCUSES the light rays falling on the retina (focuses the
visual image)
3. Iris: ring of muscle whose pigmentation gives the eye its
characteristic color (blue, brown, hazel)
Exam 2 Notes -3B. RETINA: neural tissue lining the inside back surface of
the eye (light energy is changed to neural energy)
1. Photoreceptors:
- Cells that are light-sensitive
- Two types rods & cones
a) Rods: specialized visual receptors that play a key role
in NIGHT VISION and PERIPHERAL vision
b) Cones: specialized visual receptors that play a key
role in DAYLIGHT VISION and COLOR VISION
2. Optic Nerve:
- Collection of axons from the retina that connect the eye
with the brain.
3. Blind Spot: The area at which the optic nerve exits the
retina.
4. Fovea: tiny spot in the center of the retina that contains
PRIMARILY CONES
III. THEORIES OF COLOR VISION:
A. Trichromatic: (Young-Helmholtz)
- The human eye has THREE TYPES of receptors with differing
sensitivities to different wavelengths
Primary Hues: red, green, & blue
Exam 2 Notes -4B. Opponent-Process:
- Color is perceived in three channels, where an eitheror-response is made to pairs of ANTAGONISTIC colors
• HEARING AND THE OTHER SENSES •
I. HEARING
A. Cochlea (snail like structure):
- Fluid filled
B. Basilar Membrane: runs the length of the cochlea
- Contains hair cells which convert physical stimulation
into neural signals
II. CHEMICAL SENSES
A. Taste and smell are stimulated by chemical molecules
B. Taste and smell are interrelated
C. Taste Buds: Fire neural impulses when they absorb
chemicals dissolved in your saliva
D. Hair Cells:
Exam 2 Notes -5III. POSITION SENSES:
A. Vestibular Sense: Important for posture and SENSE OF
BALANCE
B. Kinesthetic Sense: monitors the POSITION of the VARIOUS
PARTS of your body
• SELECTION AS PART OF ATTENTION •
A. STIMULUS FACTORS (Bottom up) Physical characteristics of
the stimuli
A) Contrast
D) Motion
B) Intensity
E) Novelty-Familiarity
C) Size
F) Repetition
B. PERSONAL FACTORS (Top-Down):
Mental Set: Predisposed way to perceive something (an
expectation).
C. PERCEPTUAL ORGANIZATION
1. Contour: the point at which a change in brightness occurs.
2. Gestalt: Interested in how perception enable us to group
and organize stimuli together
Exam 2 Notes -63. Figure-Ground Relationship:
Figure:
Ground:
Reversible Figure: drawing that is compatible with two
different interpretations that can shift back and forth
D. STIMULUS FACTORS: Characteristics of stimuli that help us
perceive them as being organized together in one figure
1. Proximity (or contiguity): things that are near each
other seem to belong together.
2. Similarity: We tend to group stimuli that are similar
3. Continuity: Principle of continuity reflects our tendency
to follow in whatever direction we have been led.
4. Common Fate: Elements that move together tend to be
grouped together.
5. Closure: Grouping of elements so that they create a sense
of closure, or completeness.
SUBJECTIVE CONTOURS: (special case of closure)
6. Simplicity: law of "pragnanz" we tend to group elements
that combine to form a good figure.
Exam 2 Notes -7-
• PERCEPTION OF DEPTH AND DISTANCE •
+ We do not directly sense Depth and Distance; it is
something we PERCEIVE.
+ Rely on indirect predictors of distance (binocular &
monocular cues)
+ Construction of three-dimensional vision is one of the
brain’s most important activities.
A. BINOCULAR CUES (ocular cues): are cues about distance
that one obtained by comparing the differing views of the two
eyes.
a) Retinal Disparity: (Principle Binocular depth cue)
Objects project images to slightly different locations on
your right and left retinas.
b) Convergence (Another Binocular cue): Sensing your eyes
converging toward each other as they focus on closer
objects.
c) Accommodation: is the changing of the shape of the lens by
the ciliary muscles to focus images on the retina.
B. MONOCULAR CUES (Pictorial Cues): are depth cues that can be
seen with ONE eye
a. Linear Perspective: parallel lines that run away from the
viewer seem to get closer together
b. Interposition: The shapes of near objects overlap or mask
those of more distant ones.
Exam 2 Notes -8-
c. Relative Size: If separate objects are expected to be of
the same size, the larger ones are seen as closer.
APPARENT MOTION
Image moves across the retina (stimulates successive rods &
cones)
• CONSTANCY OF PERCEPTIONS •
- Organize & Interpret stimuli
1. Size Constancy: Our tendency to view objects as stable in
size even though the size of their image changes when they
are viewed from different distances.
2. Shape Constancy: compensates for distortions due to the
three dimensional nature of the world (e.g. door)
3. Brightness Constancy: white shirt sensed as gray at night
but perceived as white.
• GEOMETRIC ILLUSIONS & IMPOSSIBLE ILLUSIONS •
Illusion: perception that is at odds with what we know as
physical reality.
1) They do not depend upon our ignorance
2) They do not "occur" at the retina
3) They do not depend on movement of the eye.
Exam 2 Notes -9-
► Chapter 5: CLASSICAL CONDITIONING ◄
I. Learning: is a relatively durable change in behavior or
knowledge that is due to experience.
II. Reflex: unlearned automatic response that occurs in the
presence of a specific stimulus
III. CLASSICAL CONDITIONING (Pavlovian Conditioning OR
Respondent Conditioning): is a type of learning in which a
neutral stimulus acquires the ability to evoke a response that
was originally evoked by another stimulus.
Example of classical conditioning
Exam 2 Notes -10A. Conditioning: is the simplest form of learning it involves
learning associations between stimuli and responses.
1) Unconditioned Stimulus (UCS): Is a stimulus that evokes
an unconditioned response without previous conditioning.
2) Unconditioned Response (UCR): Is an unlearned reaction to
an unconditioned stimulus that occurs without previous
conditioning.
3) Conditioned Stimulus (CS): Is a previously neutral
stimulus that has, through conditioning, acquired the
capacity to evoke a conditioned response.
4) Conditioned Response (CR): Is a learned reaction to a
conditioned stimulus that occurs due to previous
conditioning.
B. Orienting Reflex: a simple, unlearned response of orienting
toward, or attending to a new or unusual stimulus.
C. Habituation: is when an organism comes to ignore a stimulus
of no consequence.
Exam 2 Notes -11IV. CLASSICAL CONDITIONING PHENOMENA
A. Acquisition: Is the formation of a new conditioned response
tendency.
B. Extinction: The GRADUAL WEAKENING and DISAPPEARANCE of a
conditioned response tendency.
C. Spontaneous Recovery: is the reappearance of an
extinguished response AFTER a period of NONEXPOSURE to the
conditioned stimulus.
D. Generalization: occurs when an organism responds to new
stimuli that are SIMILAR to the ORIGINAL STIMULUS used in
conditioning
E. Discrimination (OPPOSITE OF GENERALIZATION): Occurs when
one DOES NOT RESPOND to stimuli that are similar to the
original stimulus used in conditioning.
V. CLASSICAL CONDITIONING IN EVERYDAY LIFE:
A. ADVERTISING CAMPAIGNS SOMETIMES TRY TO TAKE ADVANTAGE OF
CLASSICAL CONDITIONING:
Unconditioned Stimulus:
Unconditioned Response:
Conditioned Stimulus:
Conditioned Response:
Exam 2 Notes -12B. PHOBIC DISORDERS:
- Example of Classical Conditioning in everyday life.
C. Systematic Desensitization: the use of classical
conditioning in which a state of relaxation is paired with
anxiety-producing stimuli to alleviate irrational fears.
D. CONDITIONED TASTE AVERSION: Conditioned ONLY through the
pairing of taste stimuli & nausea.
VI. JUST WHAT IS LEARNED IN CLASSICAL CONDITIONING?
* Conditioning is now viewed as the LEARNING OF RELATIONSHIPS
that exists among events in the world.
VII. APPLYING CLASSICAL CONDITIONING TO YOUR STUDY OF PSYCHOLOGY
- Find a special place to study - RESERVED ONLY for
studying.
- Common locations can act as conditioned stimuli and
come to elicit conditioned responses.
Exam 2 Notes -13-
● OPERANT CONDITIONING ●
I. OPERANT CONDITIONING (Instrumental Learning): is a form of
learning in which voluntary responses come to be controlled by
their consequences.
Law Of Effect (Thorndike): if a response in the presence of a
stimulus leads to satisfying effects, the association between
the stimulus and the response is strengthened.
II. COURSE OF CONDITIONING:
A. Shaping: The reinforcement of closer & closer approximation
of the desired response
B. Acquisition: an increase in response rate due to the
process of operant conditioning.
C. Extinction: Gradual weakening & disappearance of a response
tendency because the response is no longer followed by a
reinforcer.
D. Spontaneous Recovery: extinguished response returns after a
rest interval.
Exam 2 Notes -14III. REINFORCEMENT
A. Reinforcement: occurs when an event following a response
strengths the tendency to make the response & can be
thought of as a reward.
1) Positive Reinforcer: occurs when a response is
strengthen because it is followed by the arrival of a
(presumably) pleasant stimulus.
2) Negative Reinforcer: a response is STRENGTHENED because
it is followed by the removal of a (presumably)
unpleasant stimulus.
TWO WAYS TO INCREASE A BEHAVIOR: we can
a. give someone something that they "like" (positive
reinforcement) OR
b. take away something that they "dislike" (negative
reinforcement)
3) Primary Reinforcers: are stimulus events that are
inherently reinforcing because they satisfy biological
needs for humans.
4) Secondary Reinforcers: are stimulus events that acquire
reinforcing qualities by being associated with primary
reinforcers.
5) Continuous Reinforcement Schedule (CRF): EVERY instance
of a designated response is reinforced.
Exam 2 Notes -156) Intermittent Reinforcement Schedules: Occurs when a
designated response is reinforced only some of the time.
a) Fixed-Ratio Schedule (FR): the reinforcer is given
after a FIXED number of non-reinforced responses
b) Fixed-Interval Schedule (FI): reinforcement is given
for the FIRST RESPONSE that occurs AFTER a FIXED
INTERVAL has elapsed.
c) Variable-Ratio Schedule (VR): the reinforcer is given
after a VARIABLE NUMBER of non-reinforced responses.
d) Variable-Interval Schedule (VI): The reinforcer is
given for the first response after a variable time
interval has elapsed.
B. PUNISHMENT: Occurs when an event that follows a response
weakens or suppresses the tendency to make the response.
1) Positive Punishment: a response is followed by the
presentation of aversive stimulus
2) Negative Punishment: a response is followed by the
removal of a pleasant stimulus.
Reinforcement
Positive
Negative
Punishment
Exam 2 Notes -16C. GENERALIZATION:
D. DISCRIMINATION:
E. Instinctive Drift: occurs when an animal's innate response
tendencies interfere with conditioning processes.
Walden Two – B. F. Skinner
You can reinforce your own actions for studying!
• COGNITIVE APPROACHES TO LEARNING •
COGNITIVE APPROACHES TO LEARNING: Learning that need not
involve an observable behavior.
Latent Learning: learning that is NOT shown in behavior at
the time it occurs.
Cognitive Map: a mental representation or a mental picture of
a physical environment due to learning.
Exam 2 Notes -17Social Learning Theory: learning can take place through
imitation and observation of models
Learning the consequences of one's behavior by observing the
consequences of someone else's behavior
Vicarious Reinforcement:
Vicarious Punishment:
Exam 2 Notes -18-
► Chapter 4: LEVELS OF CONSCIOUSNESS ◄
A. Consciousness: all mental experiences
B. Three Levels of Consciousness (Freud):
1) Conscious:
2) Preconscious:
3) Unconscious:
C. Subliminal Perception: stimulus presented below the threshold
for conscious perception.
• VARIETIES OF CONSCIOUSNESS •
A. SLEEP
1. Electroencephalogram (EEG):
a) BETA Activity: Wide awake
b) ALPHA Activity: EEG pattern, eyes closed, not
a sleep, calm and relaxed state
2. Electromyogram:
Exam 2 Notes -193. STAGES OF SLEEP
Stage 1: Brief transitional stage usually last 5-10 min.
* ALPHA waves give way to THETA waves.
Stage 2: Characterized by brief burst of higher-frequency
brain waves, sleep spindles-> fairly regular intervals
* START to get DELTA WAVES
Stage 3: 20% of EEG activity DELTA WAVES
Stage 4: More than 50% of EEG DELTA WAVES
REM Sleep (Rapid Eye Movement):
* Deep stage of sleep Difficult to awaken a person
* EEG activity dominated by BETA WAVES
* Stage where most dreaming occurs.
Atonia: Muscle tone is extremely relaxed, bodily movement
are minimal & sleeper is virtually paralyzed.
ENTIRE SLEEP CYCLE RUNS ABOUT 90 Min.
6. Dreams:
Nightmares: are anxiety arousing dreams that lead to
awakening (usually from REM sleep).
Night Terrors: Abrupt awakening from Non-Rem sleep
accompanied by intense autonomic arousal & feelings of
panic.
7. Somnambulism (sleepwalking): occurs when a sleeping
person arises and wanders about in deep Non-REM sleep
(stage 3 or 4).
Exam 2 Notes -20-
• VOLUNTARY ALTERATIONS OF CONSCIOUSNESS •
A. HYPNOSIS: an altered state of consciousness one enters
voluntarily.
* Can produce sensory distortions & hallucinations
HALLUCINATIONS: are perceptual experiences that occur
without sensory input.
1) SPECIAL PROCESS THEORY:
Hidden Observer Theory:
HIGHWAY HYPNOSIS: person drives a great distance
responding to traffic signals & other cars with no
recall of any consciousness effort to do so.
2) NONSTATE-VIEW THEORY:
B. MEDITATION: self-induced state of altered consciousness
C. ALTERING CONSCIOUSNESS WITH DRUGS
PSYCHOACTIVE DRUGS: Psychoactive Drugs are chemical
substances that modify mental, emotional, or behavioral
functioning.
Dependence:
Tolerance:
Withdrawal:
Addiction:
Drug Abuse:
Exam 2 Notes -211) STIMULANTS: are drugs that tend to increase central
nervous system activation and behavioral activity.
a) Caffeine: found in may foods as well as many varieties
of pain killers.
b) Nicotine: activate excitatory synapse in both CNS &
PNS
c) Cocaine: elevates blood pressure & heart rate,
d) Amphetamines: (Norepinephrine & Dopamine)
2) DEPRESSANTS: reduces one's awareness of external stimuli,
Alcohol:
3) Opiates, Heroine, & Barbiturates:
a) Opiates (Narcotics): can reduce or eliminate
sensation of pain, tend to ignore real-world stimuli.
Examples: Heroin & Morphine
b) Barbiturates: synthetically produced sedatives
4) HALLUCINOGENS: Are a diverse group of drugs that have a
powerful effect on mental and emotional functioning.
- Distortions in sensory and perceptual experiences.
LSD (Lysergic Acid Diethylamide):
5) MARIJUANA: A mild, relaxed euphoria, accompanied by
enhanced sensory awareness and a distorted sense of time.