Transcript The Stimulus

Current Perspectives
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Psychoanalytic
Behavioral
Cognitive
Biological
Humanistic
Others Evolutionary, Sociocultural, etc.
Psychoanalytic Early 1900s
Freud- Interpretations of Dreams (1900)
• Behavior influenced by unconscious processes
• Stressed early childhood experiences determine
later behavior
• Negative view of humanity (aggression, sex)
Early Behaviorists
Pavlov (1913)- Dog Salvation
B. F. Skinner (1930s)- Skinner Box,
rewards & punishments
Watson (1925)- Little Albert
Behaviorists (Skinner, Watson, Pavlov)
• Environment determines behavior (clean slate)
• Stimulus
Response
• Reinforcements and punishment
• Studies observable (overt) behavior and
stimuli, not concerned with internal states
Humanistic
• Carl Rogers founder
(Maslow also important)
• Emerged as a revolt against
behaviorism & psychoanalytic
approaches
• Inherent Goodness of Human Beings
• FREE WILL
• Unconditional Positive Regard
Rogers believed for a person to
grow they need an environment
that provides ‘genuineness’
(openness and self-disclosure),
acceptance (being seen with
unconditional positive regard),
and empathy (being listened to
& understood).
Without these, relationships and
healthy personalities will not
develop as they should – much
like a tree will not grow
without sunlight and water.
Cognitive
Thoughts
Stimulus
and mental processes
Mental process
Behavior
Biological
• Observable behavior given
physiological explanations
• Genetics, biochemical, neurological
What School of Psychology?
Just for practice. Write in NB
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Primal drives
Neurotransmitters
Early childhood
Mental processes
Stimulus
Free will
Interpretation of events
DNA
Unconditional Positive Regard
Psychologist vs. Psychiatrist vs. Counselor
PSYCHOLOGISTS
Masters (2 years)
Doctoral (3-5 years)
[PhD or PsyD (clinical)]
Cannot prescribe drugs
Types:
Practitioners
Academic
Researchers
COUNSELORS
 Master’s degree (MSW or MC)
 Works with less severe mental
health problems
 Family, relationship, substance
abuse, anxiety
PSYCHIATRISTS
Medical Doctor M.D.
Medical school with
internship in Psychiatry
Can prescribe drugs
Types of Psychologists
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Clinical
Counseling
Social
Experimental
Physiological/Neurological
Cognitive
Developmental
Psychometrics
Industrial/Organizational
Education/school
Forensic
The Experiment
• Only research method capable
of showing cause and effect
Experimental Method
• Review Literature of Past Research
• Formulate Hypothesis
• Design Research/Study Method
(procedures, data collection
technique, etc.)
• Collect the Data
• Analyze the Data
• Report the Findings (journal,
critique, replicate)
• Draw Conclusion or Theory on
Explanation of Findings
Hypothesis
• A statement about the relationship between two or more
variables
• Must be testable and refutable
• Instead of proving the hypothesis, science usually tries to
disprove a null hypothesis.
Null Hypothesis (H0):
opposite of hypothesis
Hypothesis Example:
Statistical Significance :
95% not due to chance
H0: Gender does not have an
effect on perceived intelligence
H1: Gender has an effect on
perceived intelligence
Variables
• Independent Variable (I.V.):
manipulated by experimenter
• Dependent Variable (D.V.):
MEASURED variable influenced
by independent
• Operational definition
• Confounding/extraneous variables
Control Group
• No treatment or placebo
• Serves as basis for comparison
• Serves to eliminate alternative explanations
Population – The larger group of people from
which a sample is drawn (who we are trying to test as a whole)
Sample: selection of people from population we will
conduct the experiment on/with
Representative: Must be a good selection of the population,
accurately representing who we are testing
Random: Every member of the pop has = chance
Stratified: Sample is put together by picking a group
statistically equal to the population
Control Measures
• Counterbalance: controls for order effects
• Single-Blind: subject unaware of assignment
• Double-Blind: subject and experimenter unaware
of placement
• Randomization
– From population (sample)
– From assignment to groups (assignment)
Correlation
A statistical value of the relationship between
two variables
Positive Correlation
As one number increases, the other increases.
Ex: Study time to GPA
Negative Correlation
As one number increases, the other decreases.
Ex: Absences to GPA
No Correlation
Variables do not affect one another in a
significant way
Ex: Height to GPA
Correlation Coefficient
• Ranges from -1.00 to 1.00
• Zero is no relationship
• -0.85 is a stronger relationship than .34
CORRELATION IS NOT CAUSATION!!
(i.e. Just because two variables have a correlation
does not mean one causes the other)
Statistics
A branch of applied mathematics that uses numbers to
describe and analyze information on a subject
Descriptive Statistics
Organize and summarize data
Central Tendency: mean, median, mode
Standard deviation: variation in data
Range: distance from smallest to largest
Inferential Statistics
Interpret data and draw conclusions
Used to test validity of hypothesis
Statistical
Significance
Statistical Analysis allows us to show that results found in our experiment
were likely not just a coincidence. If we say results are “statistically
significant” that means results are probably not due to chance.
Inferential statistics are used to check for either a 5% or 1% level of
significance.
 5% : chances are 1 in 20 that the results were due to a coincidence and not I.V.
 1% : chances are 1 in 100 that the results were due to a coincidence and not I.V.
Statistically,
Lottery tickets: 14, 3, 27, 41, 18 or 1, 2, 3, 4, 5 they are
Coin flips:
HHHHHHH
or HHTHTHT equally
likely to
occur!!
Which is more likely to occur?
Standard Deviation
When looking at data it is not sufficient to describe only the central tendency, but also
how ‘spread out’ the scores are from the mean…
Bell Curve or Normal Curve
68% are within One standard deviation from mean
95% are within Two standard deviations from mean
Skews
Other Research Methods
Ex Post Facto (after the fact)
- Independent variable already present
- Not a true independent variable, no cause and effect
- Often used due to ethical concerns
Naturalistic Observation
- Natural setting: behavior is not interfered with or altered
Survey Method
- Gathers data on attitudes and behaviors.
Case Study
- Intense study of an individual
Evaluating Research
STRENGTHS AND WEAKNESSES OF
Experiment
Correlation
Surveys
Naturalistic Observation
Case Studies
Ways to Study the Brain
CT “cat” Scan: Computerized Axial Tomography
MRI: Magnetic Resonance Imaging
fMRI: Functional Magnetic Resonance Imaging
PET Scan: Positron Emission Tomography Scan
EEG: Electroencephalograph
Neurons – What are they?
• The basic building block of the nervous system -- a nerve cell
• Neurons perform three basic tasks
– Receive
– Carry
electrochemical information
– Pass on to the next neuron
The brain is made up
of approximately
________
100
billion neurons.
Neurons – How do they work?
• Neurons “fire” - send an impulse down their length - or
they don’t “fire”
• Neurons come in a variety of shapes, sizes, etc.
• Types:
- Sensory Neurons (or afferent)
- Motor Neurons (or efferent)
- Interneurons- Over 90%, connects nerves
Parts of the Neuron - Terminals
Neuron Communication
Action Potential
• A brief electrical charge
that travels down the
axon of the neuron.
• A neural impulse
• Considered an “on”
condition of the neuron
Neuron Communication
Refractory Period
• The “recharging phase”
when a neuron, after
firing, cannot generate
another action potential
Neurotransmitters
A chemical messenger that travels
across the synapse from one
neuron to the next
Can influence whether the second
neuron will generate an action
potential or not
Researchers have discovered
hundreds of substances known
to function as neurotransmitters
…they help promote sleep, alertness,
learning and memory, motivation
and emotions
…they can also influence or cause
psychological disorders including
depression & schizophrenia
Neurotransmitters
Agonist: Mimics the action of a NT
Antagonist: Opposes the action of a NT
Endorphins: elevate pleasure/mood and reduce
pain, act by either increasing or decreasing
specific NT activity, mimic effects of opium
based drugs like morphine
Select Neurotransmitters
Acetylcholine (Ach)
– Involved in muscle movement and memory
low: Alzheimer’s
Serotonin
– Involved in mood and sleep
low: Depression
Dopamine
– Involved in movement and reward systems
low: Parkinson‘s, high: Schizophrenia
GABA (gamma-aminobutyric acid)
– Inhibitory NT
can help decrease anxiety
Norepinephrine
– Involved in arousal, mood, and sympathetic nervous system activation
Bipolar (low: Depression, high: Manic)
Opioids
– Involved in pathways that reduce pain
Endocrine System
A second type of communication
system in the body made up of
a network of glands
• Hypothalamus signals to the
pituitary
• Pituitary signals other glands of
the endocrine system to secrete
hormones
• Examples of hormones:
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Estrogen/testosterone
Thyroid
growth hormone
follicle-stimulating hormone
Divisions of the Nervous System
The Sympathetic and Parasympathetic Divisions of the
Autonomic Nervous System
Anatomy of the Brain
• Hindbrain
– Cerebellum: coordination of movement and postural reflex
– Medulla: controls vegetative function
– Pons: sleep and wake-fullness
• Midbrain
– Reticular Formation: oversees arousal and attentional processes
• Forebrain
– Limbic System - controls emotions and memory
Thalamus: primary relay station for the senses (except smell)
Hypothalamus: motivation and emotional drives
Amygdala: emotions & memory
Hippocampus: forming new memories
– Cerebral Cortex: Lobes of brain, upper, wrinkled area
– Corpus Collusum: nerve cells connecting the hemispheres of
the brain
Structures of Brain Diagram
Hindbrain Structures
• Cerebellum
• Brainstem
– medulla
– reticular formation
– pons
Forebrain’s Limbic System
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Thalamus
Hypothalamus
Amygdala
Hippocampus
Cerebral Cortex pic
Cerebral Cortex
• Frontal Lobes
– decision making, speech, abstract
thought, emotional control
• Temporal Lobes
– critical for hearing & balance
– important in memory
• Occipital Lobes
– responsible for visual processes
• Parietal Lobes
– receives sensory information
Language and the Brain
• Aphasia — partial or complete
inability to articulate ideas or
understand language because of
brain injury or damage
• Broca’s area —speech production
-located in the left frontal lobe
• Wernike’s area — plays role
understanding speech
-located in the left temporal lobe
Definitions
• Sensation
– process of detecting, converting, and
transmitting raw sensory information
from the external and internal
environments to the brain
Sense
organs:
eyes, ears,
nose, tongue,
skin, & internal
body organs
• Perception
– process of selecting, organizing and
interpreting sensory information
– enables us to recognize meaningful
objects and events
Happens in
the brain!
Sensation
• Bottom-Up Processing
Ex: you have
– Information processing beginning “at the bottom” ingredients and
with raw sensory data that are sent “up” to the brain must put them
for higher level analysis
together to make
– Data driven processing that moves from the parts to something edible
the whole
• Top-Down Processing
Ex: you have
ingredients and
– Information processing starting “at the top” with
picture of a
higher level cognitive processes (such as
completed cake
expectations and knowledge) and then “working
and you must
down”
recreate the
– Conceptually driven processing that moves from the
cake
whole to the parts
Sensation- Basic Principles
• Psychophysics
– study of the relationship between physical
characteristics of stimuli and our
psychological experience of them
– Light: brightness
– Sound: volume
– Pressure: weight
– Taste: sweetness
Sensation- Thresholds
• Absolute Threshold
– minimum stimulation needed to detect a
particular stimulus
– usually defined as the stimulus needed for
detection 50% of the time
Ex: listen to
headphones
and indicate
the earliest
you hear a
tone
• Difference Threshold
– minimum difference between two stimuli
that a subject can detect 50% of the time
– just noticeable difference (JND)
– increases with magnitude
Ex: listen to
headphones
and indicate
when you hear
a change in
volume of
sound
Easier to tell the difference
between 4 & 5Hz than
1000 & 1001Hz
Sensation- Thresholds
100
Percentage
of correct
detections
• When stimuli are
detectable less than
50% of the time
75
(below one’s absolute
threshold) they are
50
Subliminal
stimuli
25
0
Low
Absolute
threshold
Intensity of stimulus
Medium
“subliminal”.
Sensation- Thresholds
• Weber’s Law- to perceive a difference between
two stimuli, they must differ by a constant
proportion
– light intensity- 8%
– weight- 2%
– tone frequency- 0.3%
Apply it!
Come up
• Sensory Adaptation: diminished sensitivity with with 3
constant stimulation (habituation)
examples
- receptors higher up in sensory system get tired
and fire less frequently
Sensation- Thresholds
• Signal Detection Theory
– predicts how and when we detect the presence of a faint
stimulus (signal) amid background stimulation (noise)
– assumes that there is no single absolute threshold
– detection depends partly on person’s
-experience
-expectations
-motivation
-level of fatigue
Vision
Did you know major league batters can hit a 90 miles per
hour fastball 4/10 of a second after it leaves the pitcher’s
hand?
• Transduction: conversion of one form of energy to another
• Wavelength: the distance from the peak of one wave to the
peak of the next
• Hue: dimension of color determined by wavelength of light
• Intensity: amount of energy in a wave determined by
amplitude
– brightness
– loudness
Vision: Physical Properties of Waves
Short wavelength=high frequency
(bluish colors, high-pitched sounds)
Great amplitude
(bright colors, loud sounds)
Long wavelength=low frequency
(reddish colors, low-pitched sounds)
Small amplitude
(dull colors, soft sounds)
Purity: saturation, timbre
Vision: Parts of the Eye
Vision: Parts of the Eye
• Cornea: transparent covering on the front of the eye
• Pupil: adjustable opening in the center of the eye
• Iris: a ring of muscle the forms the colored portion of the eye around
the pupil and controls the size of the pupil opening
• Lens: transparent structure behind pupil that changes shape to focus
images on the retina
Accommodation: change in shape of lens focus near objects
• Retina
– 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
• Fovea: central point of focus on the back of the eye
Retina’s Reaction to Light Receptors
Rods
• Located in periphery of
retina
• detect black, white and
gray
• twilight or low light
Cones
– near center of retina (fovea)
– fine detail and color vision
– daylight or well-lit conditions
Receptors in the Human Eye
Cones
Rods
Number
6 million
120 million
Location in
retina
Center
Periphery
Sensitivity in
dim light
Low
High
Color sensitive?
Yes
No
Visual Information Processing
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Feature Detectors
– Specialized neurons in the visual cortex
respond to specific features
– shape
– angle
– movement
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Parallel Processing
– simultaneous processing of several dimensions through
multiple pathways
– color
– motion
– form
– depth
Visual Information Processing
• Trichromatic (three color) Theory
– Young and Helmholtz
– The eye contains three different types of cones
capable of responding to various wavelengths of
light
• red
• green
• blue
Visual
Information
Processing
Opponent-Process Theory: opposing retinal processes
enable color vision
“ON”
“OFF”
red
green
green red
blue
yellow
yellow
blue
black white
white black
The 2 Theories
Visual Perception:
Gestalt
Gestalt Principles
(gestalt = an organized whole)
We tend to integrate pieces of info. into
meaningful wholes
– Proximity
– Closure
– Similarity
– Simplicity (law of good form)
– Continuity
– Common Region
– Connectedness
– Phi Phenom (perceive movement)
http://en.wikipedia.org/wiki/File:Lilac-Chaser.gif
http://www1.psych.purdue.edu/Magniphi/MagniPhi.html
Visual Perception: Depth
– Depth Perception: The Visual Cliff
– Binocular Cues: clues about distance based
on the differing views of the two eyes
• 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: clues about distance based on the image in either eye
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Linear Perspective: parallel lines converge in the distance
Relative Size: if two objects are the same, the larger one is seen as closer
Interposition: the nearer object overlaps the object farther in the distance
Texture Gradient: textures are coarser the closer they are
Light and shadow: brighter objects seem closer
Height in plane: objects higher up seem farther away
– Audition
Audition (Hearing)
• the sense of hearing
– Frequency
• the number of complete wavelengths that pass a point in a given time (Hz)
– Pitch
• a tone’s highness or lowness
• depends on frequency
The Stimulus
• Vibrations of sound waves
– Amplitude: loudness
– Wavelength: pitch
– Purity: timbre
Audition:
The
Ear
• Outer Ear (pinna)
– Auditory Canal
– Eardrum (tympanic membrane)
• Middle Ear (ossicles)
– hammer
– anvil
– stirrup
• Inner Ear
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oval window
cochlea
basilar membrane
hair cells (cilia)
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
– the theory that the rate of nerve impulses traveling up the
auditory nerve matches the frequency of a tone, thus
enabling us to sense its pitch
How We Locate Sounds
• Localization of Sound
– Sound is heard in the
nearest ear first
– Sound is heard loudest in
the nearest ear
• Skin Sensations
Touch
– pressure
• only skin sensation
with identifiable
receptors
– warmth
(if something is ‘hot’ both
warm and cold receptors
are activated
simultaneously)
– cold
– pain
Numerous types of
receptors lie in varying
depths in the skin
Pain
• Gate-Control Theory
– Theory that the spinal cord contains a neurological
“gate” that blocks pain signals or allows them to
pass on to the brain
– “gate” opened by the activity of pain signals
traveling up small nerve fibers
– “gate” closed by activity in larger fibers or by
information coming from the brain
• Taste Sensations
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Taste
sweet
sour
salty
bitter
Umami
• Sensory Interaction
– the principle that one
sense may influence
another
– as when the smell of
food influences its
taste
• The Stimuli: chemical
substances that are soluble
• The Anatomy: taste buds act
as the receptors for taste
(about every two weeks)
• 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 lie on the roof of the nasal passage and
sinus
• Sense DOES NOT get filtered by thalamus
• Taste and smell interact to produce flavor
Smell
Consciousness
• Definition: An individual’s perceptions, thoughts, feelings, and
memories that are active at a given moment.
Or “an organism’s awareness of its own self and surroundings”
• Awareness of:
» Internal sensations
» External events
» Self as a unique being
» Thoughts and experiences
• Characteristics: Personal and subjective, occurring on a
continuum, and changing all the time.
• Alternate States of Consciousness (ASC): includes sleep,
dreaming, chemically induced, daydreaming, etc.
Conscious/Unconscious Continuum
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Conscious
– Info. about yourself and environment currently aware of now
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Nonconscious
– Body processes not aware of like heartbeat, respiration, digestion
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Preconscious
– Available memories (unconscious at a certain moment but capable of being recalled)
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Subconscious
– Ignore, select and reject incoming stimuli
– Ex: clock chiming the hour
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Unconscious
– Freudian slips, repressed memories, dreams, being in a coma, anesthesia
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Divided Consciousness
– Ability to do two things at once
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Controlled
vs.
 requires focused attention
that generally does interfere
with ongoing activities
(being so involved in a test don’t realize time passing)
Automatic Processes
à requires minimal attention
and generally does not interfere
with other ongoing activities
(experienced driver driving a car)
Rhythms in Humans
• Yearly - seasonal variations in appetite, sleep length, moods
….Seasonal Affective Disorder
28 day - female menstrual cycle
90 minute - we cycle through various stages of sleep
• 24 hour - Circadian Rhythms: alertness, body temp, growth hormone
secretion
Latin: circa means “about” and diem “day”
• What happens if no external cues? 25-hour cycle
• Jet lag
West to East Phase advance
East to West Phase delay
• Sleep Deprivation: form of torture, stress, after about 72 hours,
slip unwillingly into brief, repeated periods of “microsleep”