PSY 101 Section 1 Lecture
Content
Lecture Notes, Gabriel Psych101
Section 1 Page 1
LECTURE NOTES FOR SECTION 1 OF CLASS
BEGIN HERE
Introduction
What Isn’t Psychology?
“late night chats”
•
•
•
•
What do dreams mean?
Why are people the way they are?
If a tree falls in the forest and no one hears it, does it really make a sound?
Why doesn’t he/she call?
A Research Finding About Love
The Hindsight Bias
Predict Winner of Election
• Powell (1988)
The Hindsight Bias
• Predict Rape
• Janoff-Bulman et al. (1985)
What Is Psychology?
• The Scientific Study of Behavior and the mind.
What Is Psychology?
• Scientific: Systematic, objective methods of observation (book calls “empirical”)
Lecture Notes, Gabriel Psych101
Section 1 Page 2
What Is Psychology?
• Behavior
Any activity that can be observed, recorded, and measured.
What Is Psychology?
• Mind:
– All conscious and unconscious mental states
– Must be inferred
Goals of Psychology
•
Not just to describe and explain behavior but also to predict and control behavior.
The History of Psychology
Wundt
• The father of psychology
• First laboratory
• Structuralism – identify the common elements of experience
• Introspection
Functionalism
• How and why does the mind help us function in the world?
• Influences by Charles Darwin
• William James
– Amazing Ideas and Prose
– First Lab in USA
Gestalt Psychology
• The whole is more than the sum of its parts
• Visual (e.g. Neon)
Psychodynamic Theory
• Freud
• Theory of how thoughts and feelings affect behavior
• Push and pull of unconscious and conscious forces
Behaviorism
• Skinner
Lecture Notes, Gabriel Psych101
• Reaction to Psychodynamic Theory
• Reinforcement
• Study behavior for behaviors sake
Section 1 Page 3
Humanistic Psychology
• Rogers
• Reaction to Behaviorism and Psychodynamic
• People have positive values, free will, and creativity
• Goal: Personal Growth
Cognitive Approach
• How information is stored and operated on
• Reaction to Behaviorism
Neuropsychology
• Understanding how the brain works helps us to understand psychology
Evolutionary Psychology
• Natural Selection: changes in the frequency of genes in a population that occur because
those genes give an organism more chance of survival
What do psychologists do?
Research Methods
Steps
1.
2.
3.
4.
5.
6.
to Research:
Observe phenomena
Come up with hypothesis
Operationalize variables
Choose research method
Analyze data
Theory
The Story of Kitty Genovese
• Why Don’t People Help?
Lecture Notes, Gabriel Psych101
Section 1 Page 4
Come up with Hypothesis
• Hypothesis: a tentative and testable explanation of the relationship between causes and
consequences
• Exp: “the larger the number of people who are witness to an emergency, the less likely
anyone is to intervene.”
Operationalize your variables
• Variables: measurable conditions that vary
• Exp: number of people, helping
•
•
•
Independent Variable: the variables thought to “predict” the other variable
Variable thought to predict other variable
Exp: number of people
•
•
Dependent Variable: Any variable whose values are the result of changes in the
independent variable. The “predicted”
Exp: helping
•
•
Operationalization: the concrete representation of the variable of interest
Exp: what is helping?
Choose a Research Method
1. Case Study
2. Survey
3. Correlational Research
4. Experiment
Choose a Research Method
• Case Study: real life description
– Pro: rich data source
– Con: vulnerable to biases, limited generalizability
Generalizability: what inferences can you make about the phenomena’s breadth.
Survey
• Interviews or questionnaires of many participants concerning a particular phenomena of
interest
– Pros: more generalizability, wide array of topics, real life description
– Cons: vulnerable to biases, “tests” are correlational in nature
Bias: self-presentation bias, wording
Wording Biases
Lecture Notes, Gabriel Psych101
Section 1 Page 5
Correlational Studies
• Measure the independent and dependent variables in a number of cases in order to
generalize to an entire population
Correlation: A statistical measure of how closely two variables are associated
•
•
Correlations can range from -1.0 to +1.0
Correlations vary in sign (+ or -) and in magnitude (0 – 1)
Explaining Correlations
• Start with 3 variables, (X, Y, & Z) where X and Y are correlated:
– X might cause Y
– Y might cause X
– X might be correlated with Y, which causes Z
• Correlations show patterns, not causes
Correlational Studies
• Pros: tell us about relationships between variables
• Cons: say nothing about causation
• Examples: trees and crime, self-esteem
Lecture Notes, Gabriel Psych101
Section 1 Page 6
Experiment
• Manipulate variables in a controlled environment in order to assess the effects of such a
manipulation on other variables
– Pros: can draw casual influence
– Cons: vulnerable to biases, can be artificial
•
How do you assign people to levels of independent variable (conditions)?
– Let them pick?
– Time of day?
– Alphabetical order?
•
•
Hallmark of experiment is random assignment
Random assignment: assign subjects to the experiment in a way that gives each person
an equal chance of being in the experiment
•
Why? Want to make sure that nothing but IV is affecting experiment
•
Confounding variables: extraneous variables that could affect experiment
•
•
Conclusions from experiment. Do groups differ?
Statistical significance: less than 5% chance that difference could occur due to chance.
Theory
• An organized set of principles that describe, predict, and explain some phenomena
Ethical Issues
• Informed Consent: subjects sign a form that explains what the experiment is about, their
rights, and the right to stop at any time without penalty
• Internal Review Board
What
•
•
•
•
•
makes Psychological Research Scientific?
Precision (operational definitions)
Skepticism (doubt what is accepted)
Reliance on empirical evidence
Willingness to make “risky predictions” (must be falsifiable)
Openness (share data)
Lecture Notes, Gabriel Psych101
Section 1 Page 7
Psychophysiology
Methods of Psychophysiological Research
• Twin studies
• Brain damage case studies
– Phineus gage
– Used to be only way
• Lesion studies in animals
• Imaging
Electroencephalogram (EEG)
Positron Emission Tomography
• Active areas have increased blood flow
• Radioactive isotopes (small amounts) are placed in the blood
• Sensors detect radioactivity
• Different tasks show distinct activity patterns
Magnetic Resonance Imaging
• Magnetic fields align certain ions and compounds
• When field is removed, these molecules release energy as radio waves
• Kind of like an x-ray
• Provides clear, 3D images
The Nervous System
• Central Nervous System
• Peripheral Nervous System
Divisions of the Nervous System
• Central Nervous System
– Brain
– Spinal cord
• Peripheral Nervous System
– Somatic
– Autonomic
Neurons
• The cells of the nervous system
• Communicative cells
– Sensory: receive signals from outside nervous system
Lecture Notes, Gabriel Psych101
– Motor: transmit signals to muscles
– Interneurons: communicate with each other
Section 1 Page 8
Structure of a Neuron
The Neuron in Action
• Information Transfer (2 phases)
1. Presynaptic (happens within neuron)
– At rest - negatively charged
– When signals are sent channels are opened and inside becomes more positive
– When threshold is reached the neuron fires: action potential
– All or none: the firing of a neuron is like a gun
– Slow: 120 meters per second
– Myelin sheath – speeds it up.
• Multiple Scerosis
2. Postsynaptic is graded
– voltage change at receptor cite is caused chemically (neurotransmitters)
– Each neuron connected to up to 100,000 others
How Neurons Communicate
• Axon terminals release neurotransmitter
• Neurotransmitter enters synaptic gap
• Neurotransmitter binds to receptors that it fits
• Reuptake: surplus reabsorbed
Lecture Notes, Gabriel Psych101
Section 1 Page 9
Neurotransmitters
• After crossing the synapse, the neurotransmitter is reuptaken or degraded
• There are more than 40 known types
• Different neurotransmitters have different effects
• Drugs, neural diseases often affect neurotransmitters
Neurotransmitters
• Acetylcholine: important for learning, memory, muscle movement
• Serotonin: influences mood and regulates food intake
• Dopamine: important to movement and to pleasure and reward
• Norepinephrine: maintains alertness & wakefulness
Drugs
• Many drugs influence synaptic transmission
• Drugs can be agonistic or antagonistic
Agonistic Drugs
• Increase release of neurotransmitter, or
• Activate receptors, imitate neurotransmitter, or
• Inhibit reuptake of neurotransmitter
Antagonistic Drugs
• Interfere with release of neurotransmitter, or
• Occupy and block neurotransmitter sites
Peripheral Nervous System
• Somatic: voluntary muscle activity
• Autonomic
– Sympathetic: generally activates
– Parasympathetic: generally inhibits
The Brain
Brainstem
• The primitive inner core
Lecture Notes, Gabriel Psych101
Section 1 Page 10
• Medulla
– Vital involuntary functions such as sneezes, breathing (hanging)
• Pons
– Sleep and arousal
• Reticular formation
– Screens incoming information and arouses higher brain centers when needed
• Cerebellum
– Learning acquired reflexes
– Motor coordination (alcohol)
Limbic System
emotions, memory, and learning
• Thalamus
– Sensory relay station. All but smell
• Amygdala
– Fear, anger, aggression
– Story of Elliot
• Hippocampus
– Memory formation
– Story of H.M.
– Limbic System
emotions, memory, and learning
• Hypothalamus
– Regulates glands, autonomic NS, release of hormones
– Limbic System
emotions, memory, and learning
Lecture Notes, Gabriel Psych101
•
Lobes
•
•
•
•
Section 1 Page 11
Hypothalamus
– Regulates glands, autonomic NS, release of hormones
– Basic Needs: Four “F”s
of the Brain
Temporal Lobes: Auditory Perception. Categorization. Essential for social interaction
Occipital Lobes: Contain the visual cortex, associations related to visual stimuli
Parietal Lobes: Sensory integration and then project to frontal lobes. Mental
manipulation. Cross-modal matching
Frontal Lobes: “star” of brain. Contain controls for speech production, thinking, planning,
reasoning, impulse control, motivation. Phineas Gage
The Case of Phineas Gage
• Gage was a railroad construction foreman
• An 1848 explosion forced a steel tamping rod through his head
• Others said he was “…no longer Gage…”
• Lost his job, worked as a sideshow exhibit
Two Hemispheres
• Language mostly in left hemisphere
• Detecting emotion, spatial abilities, music are in right
• Right controls and received input from left side of body and vice-versa
• The Corpus Callosum Provides a pathway for communication between the hemispheres
Sperry’s Split-Brain Experiment
• Split-brain subjects could not name objects shown only to the right hemisphere
• If asked to select these objects with their left hand, they succeeded
• The right side of the brain doesn’t control speech
Plasticity in Brain & Behavior
• Some rats are housed alone in empty cages
• Their littermate twins are group-housed in cages with toys, which are changed frequently
• Richer environments led to heavier, thicker brains, more synapses, and better learning
Sensation and Perception
•
Not the same thing…
Lecture Notes, Gabriel Psych101
Section 1 Page 12
• Sensation: the conversion of a stimulus (e.g. light) to neural impulses at a receptor site
(e.g. eyes)
• Perception: interpreting those stimuli, applying meaning to them
Sensation & Perception Processes
• An age old question: If a tree falls in the forest and no one is there to hear it, does it make
a sound?
Transduction
• The process of translating physical information into neural impulses
Five Senses
• At least (e.g. equilibrium, pain)
• Each sense perceives certain types of info (e.g. light)
• Has different structures (e.g. rods and cones in eyes)
Thresholds
• Absolute Threshold
– The smallest amount of stimulation that can be detected
Absolute Sensory Thresholds
• Vision: A single candle flame from 30 miles on a dark, clear night
• Hearing: The tick of a watch from 20 feet in total quiet
• Smell: 1 drop of perfume in a 6-room apartment
• Touch: The wing of a bee on your cheek, dropped from 1 cm
• Taste: 1 tsp. Sugar in 2 gal. water
Structures of the Human Eye
Parts of the Eye
• Pupil: small opening through which light enters the eye
• Lens: transparent part of eye inside pupil that focuses light
• Retina: lining of the eye containing receptor cells that are sensitive to light
The Retina
Rods
• Mostly in the periphery
• More light sensitive; detect light and dark
• Take 20-30 minutes to fully adapt to darkness
Lecture Notes, Gabriel Psych101
Section 1 Page 13
Cones
• Mostly in the fovea
• Less light sensitive; detect colors
• Have best detail vision
• Adapt fully to darkness in 2-3 minutes
Visual Pathways
Color vision
The Young-Helmholtz trichromatic theory:
After-Image Effect
The Opponent Process Theory
Cells are connected so as to place sensations of:
After-Image Effect
• Our receptor cells become over-stimulated and then send less information into our brain
for a short while afterwards.
• Opponent color is thus seen more
Lecture Notes, Gabriel Psych101
Section 1 Page 14
Color Vision
• The trichromatic theory explains perception at the receptor level
• The opponent process theory explains it at higher brain levels
Perception
Bottom up versus top down
• Bottom up processing: use bits of information (e.g. color, brightness)
• Top down processing: use prior information
Perception is affected by context and expectations
•
•
True for auditory perception as well
Chicago Police
Critical Role of Attention
• We are surrounded by stimuli all the time
• Perception depends on attention
• Preconscious Processing
Preconscious Processing
• The processing that occurs prior to the filtering process
• Exp: dichotic listening task
– Cocktail party effect
• Exp: sensitivity to sound while sleeping. Klinger
Change Blindness
– We tend not to notice unexpected changes in our environments
• Illusion of Memory
– We think we perceive and remember more of our world than we actually do
Lecture Notes, Gabriel Psych101
Section 1 Page 15
Perceiving visual forms
• Gestalt Psychology: whole is more than the sum of its parts.
Figure-Ground
We organize the world so some parts of a stimulus appear to stand out (figure) in front of
other parts (ground)
Similarity
• We group things that are similar in color, shape, etc. into single units and see them as
belonging together
Proximity
• We perceive as a unit things that are closer together relative to other things
Good Continuation
• We group things together if they appear to form a continuous pattern
Example: lines are continued through if they cross other lines
Closure
We tend to complete figures with gaps in them, by ignoring the gaps and mentally filling in
what we believe should be there
Depth Perception
Binocular Cues
• Retinal disparity: eyes don’t see the same thing
• Convergence: eyes move inward to see things
Depth Perception
Monocular Cues
• Linear Perspective: as they get further away, objects begin to converge (get closer
together)
The Ponzo Illusion
•
Top line seems farther away
– But the retinal images of the red lines are equal!
Depth Perception
Monocular Cues
• Interposition: when something blocks another object
• Relative size: knowing the size of something and using it for perspective
• Texture Gradient: Things in foreground are more distinct and pronounced
Lecture Notes, Gabriel Psych101
Section 1 Page 16
How do we know these rules?
• Experience: blind people who regain sight have trouble perceiving depth.
• The Visual Cliff
• Devised by Gibson and Walk to test depth perception
• Glass surface, with checkerboard underneath at different heights
– Visual illusion of a cliff
– Baby can’t fall
• Mom stands across the gap
• Heartbeats of 2 month old babies are faster when over cliff
Visual Illusions
• Are they nature or nurture?
• Answer: some of both!
Müller-Lyer Illusions
•
•
Muller-Lyer only occurs in developed countries with carpentered living areas. Top down
Herman’s grid: competition among receptor cites
Taste Buds
• Photograph of tongue surface (top), magnified 75 times
• 10,000 taste buds line the tongue and mouth
– Taste receptors are down inside the “bud”
• Children have more taste buds than adults
Taste
•
•
•
•
Involves only 4 sensations: Sweet, sour, salty, bitter
Most of what we consider taste is actually smell
Texture is very important in enjoyment of food
People love fats for the smooth feeling they give food (most are tasteless)
Sensitivity to Touch
Lecture Notes, Gabriel Psych101
Section 1 Page 17
Extrasensory Perception
• Extrasensory Perception (ESP):
– The ability to perceive something without ordinary sensory information
– This has not been scientifically demonstrated
•
ESP
•
•
Three
–
–
–
types of ESP:
Telepathy – Mind-to-mind communication
Clairvoyance – Perception of remote events
Precognition – Ability to see future events
No scientific evidence
Does science know all?
*****Lecture 5*****
Thought and Language
Outline of Lecture
• Mental Representation
• Methods of Problem Solving
• Heuristics and Biases
• Language
Concept
• A mental category that groups objects or events
– Chairs
– Flying
– Dogs
How are concepts stored?
• Analog – sensory correspondence to features of the stimuli
– E.g. Pumpkin Pie
• Symbolic – not sensory but meaningful
Symbolic Representations
Lecture Notes, Gabriel Psych101
Section 1 Page 18
Schema
• Integrated collection of concepts concerning a topic or aspect of the world
• Can have schemas for anything
– Objects
– Situations
– People
Duncker's Candle Problem
• Using only the objects shown in the picture, mount the candle to the wall
Why study representations?
• One reason: can affect problem solving
• Functional Fixedness: failure to use familiar objects in novel ways
Problem Solving
• Algorithms:
Problem-solving strategies that guarantee a solution. May be time-consuming.
Heuristics:
Promising problem-solving strategies that don't guarantee a solution. Often faster.
Why do we use heuristics?
• Information processing constraints: we can only process so much info at one time
(working memory)
• Motivational Constraints: we don’t always want to do the very best (just good enough)
Availability Heuristic
• Use ease with which instances come to mind to estimate probability
•
Exp: which is more common reason for death?
– Diabetes or homicide?
– Tornado or lightning?
– Shark attack or falling airplane parts?
Availability Heuristic
• Example: how many words are there in English that could fit in:
– __ __ __ __ __ I N G
– __ __ __ __ __ __ N __
Consensus heuristic
• Assume others think like us
Lecture Notes, Gabriel Psych101
Section 1 Page 19
• When asked how others think, we use ourselves as a guide
Example of False Consensus
False Consensus Effect
Anchoring Effect
• The tendency to use the initial number as an anchor when making a judgment
• Exp:
–
–
–
Exp: How long is Mississippi river?
500 Miles?
5000 Miles?
Anchoring Effect Can also have effect with non-numerical judgments.
Which car do you prefer?
Car A
Car B
Stylish
Expensive
Good Gas Mil
Fair Service
Fair Service
Good Gas Mil
Expensive
Stylish
Laws of Sympathetic Magic
• Law of contagion
• Law of similarity
Law of contagion
• “once in contact, always in contact”
• Ex: apple juice.
– Bug in bottom of first cup
– Drink second cup?
Lecture Notes, Gabriel Psych101
Section 1 Page 20
Law of Similarity
• Image = object
Confirmation Bias
• The tendency to search for information that confirms original hypotheses
• Exp: Told story of Hannah
– ½ poor background
– ½ well-to-do
• Different academic promise
The essentials: what makes language language?
• Phonemes: the smallest units of sound in spoken language
• Exp: boy versus toy is one phoneme difference
• Humans can produce 100
• English uses 45
• Babies babble all phonemes at six months
• By one year start to limit
• Other animals have different phonemes
Syntax
• Internal structure of a sentence
• All languages have rules for how sentences are arranged – a basic part of language
• In English we need a noun and a verb “I am.”
• Broca’s area
• Broca’s aphasia
Semantics
• The meaning of a word or sentence
• Morphemes – smallest unit of meaning walk v. walking
•
•
Semantics V. Syntax:
“cloud eat haughty blue” v. “I today school go.”
Pragmatics
• The way that language conveys meaning indirectly
• E.g. “can I ask you a question?”
• E.g. “Do you know where the restroom is?”
Lecture Notes, Gabriel Psych101
Section 1 Page 21
Innate or learned?
• Empiricism: we learn syntax (behaviorists)
• Nativism: crucial parts of language are innate
• All humans learn language: ways our brains are constructed
Learning language is innate
1. Children from different cultures go through similar stages of language development
2. Children over generalize
3. Children don’t need correction to learn rules
4. Children in groups will form own language
5. Infants derive linguistic rules automatically
Other Animals and Language
• Apes can learn hundreds of signs and can communicate with them effectively
– Do not use language innately
– Can they be generative?
• Dolphins and language
• Elephants and language
LECTURE NOTES FOR SECTION 1 OF CLASS
END HERE
Section 1 Page 1
LECTURE NOTES FOR SECTION 1 OF CLASS
BEGIN HERE
Introduction
What Isn’t Psychology?
“late night chats”
•
•
•
•
What do dreams mean?
Why are people the way they are?
If a tree falls in the forest and no one hears it, does it really make a sound?
Why doesn’t he/she call?
A Research Finding About Love
The Hindsight Bias
Predict Winner of Election
• Powell (1988)
The Hindsight Bias
• Predict Rape
• Janoff-Bulman et al. (1985)
What Is Psychology?
• The Scientific Study of Behavior and the mind.
What Is Psychology?
• Scientific: Systematic, objective methods of observation (book calls “empirical”)
Lecture Notes, Gabriel Psych101
Section 1 Page 2
What Is Psychology?
• Behavior
Any activity that can be observed, recorded, and measured.
What Is Psychology?
• Mind:
– All conscious and unconscious mental states
– Must be inferred
Goals of Psychology
•
Not just to describe and explain behavior but also to predict and control behavior.
The History of Psychology
Wundt
• The father of psychology
• First laboratory
• Structuralism – identify the common elements of experience
• Introspection
Functionalism
• How and why does the mind help us function in the world?
• Influences by Charles Darwin
• William James
– Amazing Ideas and Prose
– First Lab in USA
Gestalt Psychology
• The whole is more than the sum of its parts
• Visual (e.g. Neon)
Psychodynamic Theory
• Freud
• Theory of how thoughts and feelings affect behavior
• Push and pull of unconscious and conscious forces
Behaviorism
• Skinner
Lecture Notes, Gabriel Psych101
• Reaction to Psychodynamic Theory
• Reinforcement
• Study behavior for behaviors sake
Section 1 Page 3
Humanistic Psychology
• Rogers
• Reaction to Behaviorism and Psychodynamic
• People have positive values, free will, and creativity
• Goal: Personal Growth
Cognitive Approach
• How information is stored and operated on
• Reaction to Behaviorism
Neuropsychology
• Understanding how the brain works helps us to understand psychology
Evolutionary Psychology
• Natural Selection: changes in the frequency of genes in a population that occur because
those genes give an organism more chance of survival
What do psychologists do?
Research Methods
Steps
1.
2.
3.
4.
5.
6.
to Research:
Observe phenomena
Come up with hypothesis
Operationalize variables
Choose research method
Analyze data
Theory
The Story of Kitty Genovese
• Why Don’t People Help?
Lecture Notes, Gabriel Psych101
Section 1 Page 4
Come up with Hypothesis
• Hypothesis: a tentative and testable explanation of the relationship between causes and
consequences
• Exp: “the larger the number of people who are witness to an emergency, the less likely
anyone is to intervene.”
Operationalize your variables
• Variables: measurable conditions that vary
• Exp: number of people, helping
•
•
•
Independent Variable: the variables thought to “predict” the other variable
Variable thought to predict other variable
Exp: number of people
•
•
Dependent Variable: Any variable whose values are the result of changes in the
independent variable. The “predicted”
Exp: helping
•
•
Operationalization: the concrete representation of the variable of interest
Exp: what is helping?
Choose a Research Method
1. Case Study
2. Survey
3. Correlational Research
4. Experiment
Choose a Research Method
• Case Study: real life description
– Pro: rich data source
– Con: vulnerable to biases, limited generalizability
Generalizability: what inferences can you make about the phenomena’s breadth.
Survey
• Interviews or questionnaires of many participants concerning a particular phenomena of
interest
– Pros: more generalizability, wide array of topics, real life description
– Cons: vulnerable to biases, “tests” are correlational in nature
Bias: self-presentation bias, wording
Wording Biases
Lecture Notes, Gabriel Psych101
Section 1 Page 5
Correlational Studies
• Measure the independent and dependent variables in a number of cases in order to
generalize to an entire population
Correlation: A statistical measure of how closely two variables are associated
•
•
Correlations can range from -1.0 to +1.0
Correlations vary in sign (+ or -) and in magnitude (0 – 1)
Explaining Correlations
• Start with 3 variables, (X, Y, & Z) where X and Y are correlated:
– X might cause Y
– Y might cause X
– X might be correlated with Y, which causes Z
• Correlations show patterns, not causes
Correlational Studies
• Pros: tell us about relationships between variables
• Cons: say nothing about causation
• Examples: trees and crime, self-esteem
Lecture Notes, Gabriel Psych101
Section 1 Page 6
Experiment
• Manipulate variables in a controlled environment in order to assess the effects of such a
manipulation on other variables
– Pros: can draw casual influence
– Cons: vulnerable to biases, can be artificial
•
How do you assign people to levels of independent variable (conditions)?
– Let them pick?
– Time of day?
– Alphabetical order?
•
•
Hallmark of experiment is random assignment
Random assignment: assign subjects to the experiment in a way that gives each person
an equal chance of being in the experiment
•
Why? Want to make sure that nothing but IV is affecting experiment
•
Confounding variables: extraneous variables that could affect experiment
•
•
Conclusions from experiment. Do groups differ?
Statistical significance: less than 5% chance that difference could occur due to chance.
Theory
• An organized set of principles that describe, predict, and explain some phenomena
Ethical Issues
• Informed Consent: subjects sign a form that explains what the experiment is about, their
rights, and the right to stop at any time without penalty
• Internal Review Board
What
•
•
•
•
•
makes Psychological Research Scientific?
Precision (operational definitions)
Skepticism (doubt what is accepted)
Reliance on empirical evidence
Willingness to make “risky predictions” (must be falsifiable)
Openness (share data)
Lecture Notes, Gabriel Psych101
Section 1 Page 7
Psychophysiology
Methods of Psychophysiological Research
• Twin studies
• Brain damage case studies
– Phineus gage
– Used to be only way
• Lesion studies in animals
• Imaging
Electroencephalogram (EEG)
Positron Emission Tomography
• Active areas have increased blood flow
• Radioactive isotopes (small amounts) are placed in the blood
• Sensors detect radioactivity
• Different tasks show distinct activity patterns
Magnetic Resonance Imaging
• Magnetic fields align certain ions and compounds
• When field is removed, these molecules release energy as radio waves
• Kind of like an x-ray
• Provides clear, 3D images
The Nervous System
• Central Nervous System
• Peripheral Nervous System
Divisions of the Nervous System
• Central Nervous System
– Brain
– Spinal cord
• Peripheral Nervous System
– Somatic
– Autonomic
Neurons
• The cells of the nervous system
• Communicative cells
– Sensory: receive signals from outside nervous system
Lecture Notes, Gabriel Psych101
– Motor: transmit signals to muscles
– Interneurons: communicate with each other
Section 1 Page 8
Structure of a Neuron
The Neuron in Action
• Information Transfer (2 phases)
1. Presynaptic (happens within neuron)
– At rest - negatively charged
– When signals are sent channels are opened and inside becomes more positive
– When threshold is reached the neuron fires: action potential
– All or none: the firing of a neuron is like a gun
– Slow: 120 meters per second
– Myelin sheath – speeds it up.
• Multiple Scerosis
2. Postsynaptic is graded
– voltage change at receptor cite is caused chemically (neurotransmitters)
– Each neuron connected to up to 100,000 others
How Neurons Communicate
• Axon terminals release neurotransmitter
• Neurotransmitter enters synaptic gap
• Neurotransmitter binds to receptors that it fits
• Reuptake: surplus reabsorbed
Lecture Notes, Gabriel Psych101
Section 1 Page 9
Neurotransmitters
• After crossing the synapse, the neurotransmitter is reuptaken or degraded
• There are more than 40 known types
• Different neurotransmitters have different effects
• Drugs, neural diseases often affect neurotransmitters
Neurotransmitters
• Acetylcholine: important for learning, memory, muscle movement
• Serotonin: influences mood and regulates food intake
• Dopamine: important to movement and to pleasure and reward
• Norepinephrine: maintains alertness & wakefulness
Drugs
• Many drugs influence synaptic transmission
• Drugs can be agonistic or antagonistic
Agonistic Drugs
• Increase release of neurotransmitter, or
• Activate receptors, imitate neurotransmitter, or
• Inhibit reuptake of neurotransmitter
Antagonistic Drugs
• Interfere with release of neurotransmitter, or
• Occupy and block neurotransmitter sites
Peripheral Nervous System
• Somatic: voluntary muscle activity
• Autonomic
– Sympathetic: generally activates
– Parasympathetic: generally inhibits
The Brain
Brainstem
• The primitive inner core
Lecture Notes, Gabriel Psych101
Section 1 Page 10
• Medulla
– Vital involuntary functions such as sneezes, breathing (hanging)
• Pons
– Sleep and arousal
• Reticular formation
– Screens incoming information and arouses higher brain centers when needed
• Cerebellum
– Learning acquired reflexes
– Motor coordination (alcohol)
Limbic System
emotions, memory, and learning
• Thalamus
– Sensory relay station. All but smell
• Amygdala
– Fear, anger, aggression
– Story of Elliot
• Hippocampus
– Memory formation
– Story of H.M.
– Limbic System
emotions, memory, and learning
• Hypothalamus
– Regulates glands, autonomic NS, release of hormones
– Limbic System
emotions, memory, and learning
Lecture Notes, Gabriel Psych101
•
Lobes
•
•
•
•
Section 1 Page 11
Hypothalamus
– Regulates glands, autonomic NS, release of hormones
– Basic Needs: Four “F”s
of the Brain
Temporal Lobes: Auditory Perception. Categorization. Essential for social interaction
Occipital Lobes: Contain the visual cortex, associations related to visual stimuli
Parietal Lobes: Sensory integration and then project to frontal lobes. Mental
manipulation. Cross-modal matching
Frontal Lobes: “star” of brain. Contain controls for speech production, thinking, planning,
reasoning, impulse control, motivation. Phineas Gage
The Case of Phineas Gage
• Gage was a railroad construction foreman
• An 1848 explosion forced a steel tamping rod through his head
• Others said he was “…no longer Gage…”
• Lost his job, worked as a sideshow exhibit
Two Hemispheres
• Language mostly in left hemisphere
• Detecting emotion, spatial abilities, music are in right
• Right controls and received input from left side of body and vice-versa
• The Corpus Callosum Provides a pathway for communication between the hemispheres
Sperry’s Split-Brain Experiment
• Split-brain subjects could not name objects shown only to the right hemisphere
• If asked to select these objects with their left hand, they succeeded
• The right side of the brain doesn’t control speech
Plasticity in Brain & Behavior
• Some rats are housed alone in empty cages
• Their littermate twins are group-housed in cages with toys, which are changed frequently
• Richer environments led to heavier, thicker brains, more synapses, and better learning
Sensation and Perception
•
Not the same thing…
Lecture Notes, Gabriel Psych101
Section 1 Page 12
• Sensation: the conversion of a stimulus (e.g. light) to neural impulses at a receptor site
(e.g. eyes)
• Perception: interpreting those stimuli, applying meaning to them
Sensation & Perception Processes
• An age old question: If a tree falls in the forest and no one is there to hear it, does it make
a sound?
Transduction
• The process of translating physical information into neural impulses
Five Senses
• At least (e.g. equilibrium, pain)
• Each sense perceives certain types of info (e.g. light)
• Has different structures (e.g. rods and cones in eyes)
Thresholds
• Absolute Threshold
– The smallest amount of stimulation that can be detected
Absolute Sensory Thresholds
• Vision: A single candle flame from 30 miles on a dark, clear night
• Hearing: The tick of a watch from 20 feet in total quiet
• Smell: 1 drop of perfume in a 6-room apartment
• Touch: The wing of a bee on your cheek, dropped from 1 cm
• Taste: 1 tsp. Sugar in 2 gal. water
Structures of the Human Eye
Parts of the Eye
• Pupil: small opening through which light enters the eye
• Lens: transparent part of eye inside pupil that focuses light
• Retina: lining of the eye containing receptor cells that are sensitive to light
The Retina
Rods
• Mostly in the periphery
• More light sensitive; detect light and dark
• Take 20-30 minutes to fully adapt to darkness
Lecture Notes, Gabriel Psych101
Section 1 Page 13
Cones
• Mostly in the fovea
• Less light sensitive; detect colors
• Have best detail vision
• Adapt fully to darkness in 2-3 minutes
Visual Pathways
Color vision
The Young-Helmholtz trichromatic theory:
After-Image Effect
The Opponent Process Theory
Cells are connected so as to place sensations of:
After-Image Effect
• Our receptor cells become over-stimulated and then send less information into our brain
for a short while afterwards.
• Opponent color is thus seen more
Lecture Notes, Gabriel Psych101
Section 1 Page 14
Color Vision
• The trichromatic theory explains perception at the receptor level
• The opponent process theory explains it at higher brain levels
Perception
Bottom up versus top down
• Bottom up processing: use bits of information (e.g. color, brightness)
• Top down processing: use prior information
Perception is affected by context and expectations
•
•
True for auditory perception as well
Chicago Police
Critical Role of Attention
• We are surrounded by stimuli all the time
• Perception depends on attention
• Preconscious Processing
Preconscious Processing
• The processing that occurs prior to the filtering process
• Exp: dichotic listening task
– Cocktail party effect
• Exp: sensitivity to sound while sleeping. Klinger
Change Blindness
– We tend not to notice unexpected changes in our environments
• Illusion of Memory
– We think we perceive and remember more of our world than we actually do
Lecture Notes, Gabriel Psych101
Section 1 Page 15
Perceiving visual forms
• Gestalt Psychology: whole is more than the sum of its parts.
Figure-Ground
We organize the world so some parts of a stimulus appear to stand out (figure) in front of
other parts (ground)
Similarity
• We group things that are similar in color, shape, etc. into single units and see them as
belonging together
Proximity
• We perceive as a unit things that are closer together relative to other things
Good Continuation
• We group things together if they appear to form a continuous pattern
Example: lines are continued through if they cross other lines
Closure
We tend to complete figures with gaps in them, by ignoring the gaps and mentally filling in
what we believe should be there
Depth Perception
Binocular Cues
• Retinal disparity: eyes don’t see the same thing
• Convergence: eyes move inward to see things
Depth Perception
Monocular Cues
• Linear Perspective: as they get further away, objects begin to converge (get closer
together)
The Ponzo Illusion
•
Top line seems farther away
– But the retinal images of the red lines are equal!
Depth Perception
Monocular Cues
• Interposition: when something blocks another object
• Relative size: knowing the size of something and using it for perspective
• Texture Gradient: Things in foreground are more distinct and pronounced
Lecture Notes, Gabriel Psych101
Section 1 Page 16
How do we know these rules?
• Experience: blind people who regain sight have trouble perceiving depth.
• The Visual Cliff
• Devised by Gibson and Walk to test depth perception
• Glass surface, with checkerboard underneath at different heights
– Visual illusion of a cliff
– Baby can’t fall
• Mom stands across the gap
• Heartbeats of 2 month old babies are faster when over cliff
Visual Illusions
• Are they nature or nurture?
• Answer: some of both!
Müller-Lyer Illusions
•
•
Muller-Lyer only occurs in developed countries with carpentered living areas. Top down
Herman’s grid: competition among receptor cites
Taste Buds
• Photograph of tongue surface (top), magnified 75 times
• 10,000 taste buds line the tongue and mouth
– Taste receptors are down inside the “bud”
• Children have more taste buds than adults
Taste
•
•
•
•
Involves only 4 sensations: Sweet, sour, salty, bitter
Most of what we consider taste is actually smell
Texture is very important in enjoyment of food
People love fats for the smooth feeling they give food (most are tasteless)
Sensitivity to Touch
Lecture Notes, Gabriel Psych101
Section 1 Page 17
Extrasensory Perception
• Extrasensory Perception (ESP):
– The ability to perceive something without ordinary sensory information
– This has not been scientifically demonstrated
•
ESP
•
•
Three
–
–
–
types of ESP:
Telepathy – Mind-to-mind communication
Clairvoyance – Perception of remote events
Precognition – Ability to see future events
No scientific evidence
Does science know all?
*****Lecture 5*****
Thought and Language
Outline of Lecture
• Mental Representation
• Methods of Problem Solving
• Heuristics and Biases
• Language
Concept
• A mental category that groups objects or events
– Chairs
– Flying
– Dogs
How are concepts stored?
• Analog – sensory correspondence to features of the stimuli
– E.g. Pumpkin Pie
• Symbolic – not sensory but meaningful
Symbolic Representations
Lecture Notes, Gabriel Psych101
Section 1 Page 18
Schema
• Integrated collection of concepts concerning a topic or aspect of the world
• Can have schemas for anything
– Objects
– Situations
– People
Duncker's Candle Problem
• Using only the objects shown in the picture, mount the candle to the wall
Why study representations?
• One reason: can affect problem solving
• Functional Fixedness: failure to use familiar objects in novel ways
Problem Solving
• Algorithms:
Problem-solving strategies that guarantee a solution. May be time-consuming.
Heuristics:
Promising problem-solving strategies that don't guarantee a solution. Often faster.
Why do we use heuristics?
• Information processing constraints: we can only process so much info at one time
(working memory)
• Motivational Constraints: we don’t always want to do the very best (just good enough)
Availability Heuristic
• Use ease with which instances come to mind to estimate probability
•
Exp: which is more common reason for death?
– Diabetes or homicide?
– Tornado or lightning?
– Shark attack or falling airplane parts?
Availability Heuristic
• Example: how many words are there in English that could fit in:
– __ __ __ __ __ I N G
– __ __ __ __ __ __ N __
Consensus heuristic
• Assume others think like us
Lecture Notes, Gabriel Psych101
Section 1 Page 19
• When asked how others think, we use ourselves as a guide
Example of False Consensus
False Consensus Effect
Anchoring Effect
• The tendency to use the initial number as an anchor when making a judgment
• Exp:
–
–
–
Exp: How long is Mississippi river?
500 Miles?
5000 Miles?
Anchoring Effect Can also have effect with non-numerical judgments.
Which car do you prefer?
Car A
Car B
Stylish
Expensive
Good Gas Mil
Fair Service
Fair Service
Good Gas Mil
Expensive
Stylish
Laws of Sympathetic Magic
• Law of contagion
• Law of similarity
Law of contagion
• “once in contact, always in contact”
• Ex: apple juice.
– Bug in bottom of first cup
– Drink second cup?
Lecture Notes, Gabriel Psych101
Section 1 Page 20
Law of Similarity
• Image = object
Confirmation Bias
• The tendency to search for information that confirms original hypotheses
• Exp: Told story of Hannah
– ½ poor background
– ½ well-to-do
• Different academic promise
The essentials: what makes language language?
• Phonemes: the smallest units of sound in spoken language
• Exp: boy versus toy is one phoneme difference
• Humans can produce 100
• English uses 45
• Babies babble all phonemes at six months
• By one year start to limit
• Other animals have different phonemes
Syntax
• Internal structure of a sentence
• All languages have rules for how sentences are arranged – a basic part of language
• In English we need a noun and a verb “I am.”
• Broca’s area
• Broca’s aphasia
Semantics
• The meaning of a word or sentence
• Morphemes – smallest unit of meaning walk v. walking
•
•
Semantics V. Syntax:
“cloud eat haughty blue” v. “I today school go.”
Pragmatics
• The way that language conveys meaning indirectly
• E.g. “can I ask you a question?”
• E.g. “Do you know where the restroom is?”
Lecture Notes, Gabriel Psych101
Section 1 Page 21
Innate or learned?
• Empiricism: we learn syntax (behaviorists)
• Nativism: crucial parts of language are innate
• All humans learn language: ways our brains are constructed
Learning language is innate
1. Children from different cultures go through similar stages of language development
2. Children over generalize
3. Children don’t need correction to learn rules
4. Children in groups will form own language
5. Infants derive linguistic rules automatically
Other Animals and Language
• Apes can learn hundreds of signs and can communicate with them effectively
– Do not use language innately
– Can they be generative?
• Dolphins and language
• Elephants and language
LECTURE NOTES FOR SECTION 1 OF CLASS
END HERE
