Description
Lecture 1/Chapter 1 – What is Psychology?
Psychology is…
… the study of the mind (mental activity), brain (contain the biological processes that produce the mental activity), and behavior (observable human actions) … a young field, with many “known” matters still being debated today
… about describing phenomena AND “understanding the mechanistic underpinnings of such phenomena”
Psychologists…
… study “normal” brain functions and behaviors
… often prove common sense to be WRONG
… want to know WHY an answer is as such (emphasis on questions)
Critical thinking = to systematically question and evaluate info using well-supported info Requires healthy questioning and optimism
In psych, this adds to our understanding of how people typically think when presented with info
Many of us function as “intuitive psychologists,” but many of our intuitions & beliefs are wrong
Typical errors of psychological science:
Confirmation bias - ignoring evidence that doesn’t support our own belief Self-serving bias – ignoring our own inadequacies
Inaccurately judging source credibility
Misunderstand/Not using statistics
Seeing relationships that do not exist
Making relative comparisons
Accepting post-facto explanations
Mental shortcuts
**Ignore names, focus on ideas Don't forget about the age old question of What is phosphofructokinase?
History of Psychology:
Nature/Nurture Debate – whether psychological characteristics are embedded in our DNA or acquired through education, experience, and culture
Mind/Body Problem – whether mind and body are separate and distinct, or is the mind the physical brain’s subjective experience
*Early psychological research was largely aimed towards understanding the subjective mind
Aristotle: The heart is the center of our sensory experience, and the brain is for cooling the blood Until 1860’s, psychology was a sub-discipline of philosophy
Phrenology = it was believed that one’s character traits can be interpreted from the localized bumps on one’s head If you want to learn more check out What is wax?
A precursor to psychology & neuroscience
2 big ideas they discovered:
1) Computational Organology = the brain can be split into different regions, each with different functions ???? space in the brain matters
Why false? They didn’t parcel it accurately
2) Experienced Dependent Plasticity = brain changes as a result of use; the tissue is constantly growing
Why false? They used localized bumps on a person’s head to interpret character traits, but the brain can’t “push out” large bone
Gustav Fechnar: A physicist interested in the relationship between the external environment and internal mental state
Father of psychophysics – how the world and the stimuli outside of us effect the stimuli inside our mind We also discuss several other topics like Classical realism
Don't forget about the age old question of What is cross price elasticity of demand?
Wilhelm Wundt: 1st person to measure the speed of a thought (speeded reaction time)
Sigmund Freud: Theory of personality and methods of therapy that emphasized unconscious motives and conflict
His ideas are non-falsifiable (can’t be proven wrong)
Freudianism lead to ???? Behaviorism Don't forget about the age old question of
who insisted on accuracy and comprehensive coverage in the new york world?
Freudianism = the emphasis on unconscious
Behaviorism (Watson & Skinner) = theory that focused only on how observable environmental stimuli affect behavioral responses Don't forget about the age old question of What institutionalized system of communication conveys information and symbolic messages to audiences through print and technology?
Mental processes were deemed scientifically irrelevant in explaining behavior Their ideas of “what is the mind” were all assumed
When simple laws of behaviorism could not explain all learning…
Miller: Cognitive Revolution = the study of how people think, learn, and remember (Actually the 2nd cognitive revolution)
Cognitive psychologists joined forced with neuroscientists, computer scientists, and philosophers ???? emergence of cognitive neuroscience
Perspectives in psychology:
Behavioral = Belief: all behavior is acquired from learning
Focus: observable behavior
Prominent in animal training
Cognitive = Focus: mechanistic understanding of internal mental processes Divides the brain into individual processes (i.e. memory, attention, perception, decision making, language)
Neuroscience = Biological bases for mind and behavior
Evolutionary = Belief: human behavior & processes as evolved adaptation via natural selection Psychoanalytic = Belief: our behavior & feelings are affected by unconscious motives (stem from childhood experiences)
Lecture 2/Chapter 2 – Methods
The Scientific Method: Theory, Hypothesis, Research
4 primary goals of science: description, prediction, control, & explanation The scientific method helps psychologists achieve this Cyclical process:
Theory
(explanation based on observation)
Hypothesis
(prediction based on theory)
Research
(test of the hypothesis that leads to data that…)
Support Theory
(refine with new hypotheses and research)
Reject/Doesn’t Support Theory (discard or revise & test again)
Good theory evolves over time ???? more accurate model of natural phenomena Good theory ???? many testable hypotheses/predictions
Hypothesis vs. Prediction
Hypothesis = an [unconfirmed] suspicion that is used to draw conclusions based on known facts Lead to further investigation
Prediction = the action of guessing future events (example: a prophecy, the forecast) EXAMPLE:
Observation: Computer is not turning on
Hypothesis 1: Battery ran out of charge
Hypothesis 2: Computer needs to be replaced
Prediction 1 (with methods): Plugging the computer into the charger will make it the computer turn on after a couple of minutes
“If the dead battery hypothesis is correct, and I plug the computer into the charger, then the computer will turn on”
Computer turns on!
Test of hypothesis 1 supports the hypothesis ???? the above hypothesis is both testable and falsifiable
Focus on a hypothesis ???? make a prediction ???? do research ???? analyze weather the data supports or rejects the hypothesis ???? report results & conduct further research
Unexpected discoveries sometimes occur, but they are only beneficial to researchers who are prepared to see their importance
3 Types of Designs:
Research Method:
Experimental Non-Experimental
Descriptive Correlation
Observational Developmental
Longitudinal Cross-sectional
1) Descriptive = observing the behavior of subjects
a) Observational Studies:
Advantages:
Valuable in initial stages of research when characterizing phenomena Occur in real-life setting (natural)
Disadvantages:
Occur in real-life setting (little control)
People might change their behavior if they know someone is watching them Observer bias = errors from observer expectations Naturalistic observations = passive
Participant observations = active
b) Developmental Designs:
1. Longitudinal = observing one same group of people over a long period of time Advantages:
Informs researchers about developmental changes (effects of age on the
same people)
Disadvantages:
Expensive (time & $)
Lose participants over time
2. Cross-sectional = observing multiple groups at the same time Advantages:
Fast & cheap
Disadvantages:
Cohort effect = unidentifiable variables may be involved; not
generalizable
2) Correlational = examine how variables are naturally related in real life; no manipulations Correlation Coefficient = a value between -1.0 and +1.0 that indicates the strength (-/+) of a relationship
Advantages:
Rely on naturally occurring relationships
Allows measurement of variables that most likely can’t be controlled Ex: criminal activity
Disadvantages:
CORRELATION ≠ CAUSATION
Just because there is a correlation between people who text while driving and people who die in car accidents, does NOT mean that all people who
die in car accidents were texting!!
Cannot be used to make casual conclusions
3rd variable problem – researches cannot be confident that there isn’t another variable that is actually causing the difference in the variables of interest
3) Experimental = researcher manipulates one variable to examine the effect on a second variable
Independent Variable = the manipulated variable
Dependent Variable = the variable being measured
Independent ???? (causes) change in the Dependent
Experimental Group = the group that receives the independent variable
Control Group = the comparison group that does NOT receive the independent variable (given placebo)
Confound = another variable (other than the independent variable) that affects the dependent variable
Random Sampling:
Psychologists want to generalize findings from a sample of individuals to the population of people beyond the study
External Validity = the degree to which the findings can be generalized outside the lab Random Sampling = everyone in the population has an equal chance of being selected Selection Bias = groups aren’t entirely equal because participants in different groups differ in unexpected ways, affecting the dependent variable
Solution:
Random Assignment = each participant has an equal chance of being assigned to any level of the independent variable
Balances out known & unknown factors, increasing likelihood that groups are equal
Data Collecting Methods:
1) Observation – systematic evaluation and coding of evident behavior
What should the researcher consider?
Whether to conduct in a lab or natural environment
How to collect the data
Whether or not the observer should be visible
Reactivity: People being observed might change their behavior if they know they’re being observed
2) Case Studies – intensive examinations of “unusual” subjects
Patient H.M. lobotomy ???? discoveries about many functions in the brain, including amnesia, memory formation, motor skills, & more.
Advantages:
Provides extensive data about a few individuals/group
Gives opportunity to investigate a situation that can’t be manipulated in a lab Disadvantages:
Hard to determine how much info taken from case studies can be generalized to normal population
3) Self-report – surveys or interviews are used to gather data from a lot of people in a short time Advantages:
Gather large sums of data in a short amount of time
In-person interviews gives the researcher a chance to try new lines of questioning Disadvantages:
Interviewer might influence report
Participants may not remember info correctly
Participants might bring bias into their own self reports
Hard to determine if an answer is honest
Socially desirable responding = someone responds in a way that is
socially desirable but not accurate
Better-than-average effect = someone might describe him/herself more
positively than accurate
4) Behavioral Response Performance – researchers quantify cognitive processes in response to a particular stimulus
2 major measures:
1. Reaction time
2. Response accuracy
Advantages:
Simple way to measure cognition & perception
Less likely to contain observer bias (when designed properly) Disadvantages:
Potentially expensive & time consuming
Not sure how generalizable findings are to real-life setting 5) Body/Brain Activity – how the body/brain (physiology) responds to events Polygraph = measures physiological activity (heart rate, blood pressure, perspiration rate) related to behaviors or mental condition
Electrophysiology: = a way to collect data by measuring electrical activity in the brain Electroencephalograph (EEG) = a device that measures brain activity
The relationship between the brain activity responses on the paper and
their localization in the brain is slightly off
Brain Imaging:
Positron Emission Tomography (PET) = a device that produces a computer aided reconstruction of the brain’s metabolic activity by tracking a radioactive substance
Magnetic Resonance Imaging (MRI) = a device that produces a strong magnetic force that the brain tissue respond to
Functional Magnetic Resonance Imaging (fMRI) = a device that indirectly measures blood flow by evaluating the changes in the blood’s oxygen level Brain Stimulation:
Transcranial Magnetic Stimulation (TMS) = a device with a very fast,
powerful magnetic force disrupts brain activity momentarily in a specific brain region
Example: placing it over the part of the brain that controls vision will
temporarily cause someone to lose their ability to see
Useful for examining which regions are required for certain psychological functions
Advantages:
Identify physical response to external events
Connects neural processes & behavior
Disadvantages:
Expensive
Many of these techniques are affected by 3rd variables (correlational – excluding brain stimulation)
Can be hard to decipher relevant data
6) Animal Research – assumes that forces that control the behavior of all animals apply their effects in similar ways
Used because some research can’t [ethically] be performed on humans
Lecture 3/Chapter 3 – Neuroscience
Neurons = basic building blocks of the nervous system; receive & send out info throughout the nervous system
Neural Networks = a string of neurons
Electrical Impulses = the power behind neurons
Chemical Signals = the way that neurons communicate with other nerve cells Dendrites = senses chemical signals from neighboring neurons
Soma (cell body) = keeps the neuron alive & functioning; produces neurotransmitters Axon = transmits electrical impulses (can be as long as 2 meters in humans) Myelin sheath = fatty fibers that surrounds & insulates axons; made up of glial cells, which facilitate transmission
Impaired ???? MS
Terminal buttons = bulbous end of an axon; the end at which communication between neurons occurs
Synapse = gaps between neurons that supports the neurons’ chemical communication 1. Presynaptic neuron = neuron before
2. Postsynaptic neuron = neuron after
1.
2.
Process: Messages are received by the dendrites ???? transmitted along the axon ???? sent to other neurons via chemical substances released from the terminal buttons across the synaptic cleft
Neutral Responses:
Electrical Voltage = the balance between positive & negative ions within the cell that determine the condition of the neuron
Resting membrane potential = when the negative to positive ion ratio is greater INSIDE the neuron than outside (resting state is slightly neg.)
Action potential (neural firing) = when a neuron transports an electrical signal to another neuron; there is an increase in voltage that goes beyond the neuron’s firing threshold Process:
Resting state – when the ion channels are closed; the neuron creates an action potential because of the difference in concentration between the intercellular space and the extracellular space (high concentration of Na+ outside neuron and of K+ inside) –voltage difference = -70mV (created by leaky ion channels)
Sodium-Potassium pump = exchanges 3 Na+ ions out for 2 K+in
Depolarization – when a neuron is stimulated by a presynaptic neuron the Na+ channels open & positive ions enter (more + inside than outside) ???? chain reaction down the axon. These will then close and K+ channels will open, letting out positive K+ ions
Repolarization – intercellular space becomes negative again
Hyperpolarization – when the cell has let out too many ions & it becomes more negative than the cell’s resting potential
Neurotransmitters:
Neurotransmitters = chemicals that are released from the neuron’s terminal buttons due to action potentials
The chemical that allows 2 neurons to communicate
Travel across the synaptic cleft and are received by receptors on the postsynaptic neurons’ dendrites.
When the neurotransmitters binds with a receptor the neuron’s voltage is altered
Agonist = drugs/chemicals that increase the effect of the neurotransmitter How? Increases neurotransmitter production
Helps increase the release
Activates the receptors to the neurotransmitters
Antagoist = drugs/chemicals that decrease the effect of the neurotransmitter How? Interferes with the release of the neurotransmitter
Occupies the receptors thereby blocking the neurotransmitters from being received
Causes the neurotransmitters to leaf from the synaptic vesicles
All-or-none Principle:
All-or-none principle states that “a neuron will either fire or not (no ‘weak’ or ‘strong’)” Neuronal intensity is determined by the frequency of signals it receives, per unit time (spikes/sec)
Adult brain has approx. 100 billion neurons!
2 types of Cranial Tissue:
Gray Matter = dendrites & cell bodies of neurons
TRICK (when looking at a diagram): the flowers/leaves
White Matter = myelinated axons
TRICK (when looking at a diagram): the branches/trunk
Basic Components:
1) Central Nervous System = BRAIN & SPINAL CORD*
The Spinal Cord = the main line connecting the brain to the outside world Biological Purpose: sends sensory info to the brain & sends motor signals from the brain
Physical Purpose: connects central & peripheral nervous systems Damage ???? paralysis
The Brain Stem = survival basis (houses breathing, heartbeat, pain, consciousness) Damage ???? death
The Cerebellum = function basis (important for normal motor skills, motor memory, & learning)
Damage: [to side lobes] ???? can’t control your limbs
[to nodes on the bottom] ???? balance problems
Subcortical Structure:
1. Hypothalamus = body function regulator
Job: regulates internal organ function, body temp, body rhythms, blood pressure, & blood glucose levels
Also used for “hormone-driven motivated behaviors” (thirst, hunger,
anger, lust)
Damage ???? regulatory problems, like overeating
2. Thalamus = sensory gateway
Job: receives, organizes & sends out sensory info to the cortex (EXCEPT smell) Partially closes to incoming sensations during sleep Damage ???? sensory shortage
3. Hippocampus = memory headquarters
Job: involved in how we remember the arrangement of places & objects in space Damage ???? memory-related impairment; issues with special navigation; Anmesia 4. Amygdala = emotion base (TRICK: Amy is an emotional bitch)
Job: involved in our development of negative & positive emotional responses Damage ???? heavily reduced fear and anger
5. Basal ganglia = tells us to move (TRICK: when a gang comes near you, you are motivated to move!)
Job: produces movement, and important for motivating behavior & experiencing reward
Damage ???? Parkinson’s Disease (or similar actions); can affect one’s ability to learn movements and habits
The Cortex: 2 hemispheres, 4 lobes
Split into 2 hemispheres (left & right)
Cerebral Cortex = the outer layer of the cerebral hemisphere
Purpose: hosts all thoughts, detailed perceptions & complex behaviors
Corpus Callosum = a huge axon bridge connecting the 2 hemispheres
Purpose: serves as a info passageway between the hemispheres Damaged ???? hands work independent of each other
The cortex is made up of 4 lobes:
1. Frontal – complex reasoning, thinking, planning
Disproportionally larger in humans
Damage ???? can’t make decisions ???? impulsivity & risky behavior
2. Parietal – touch, spatial sense & navigation, spatial attention
Damage ???? impaired motor control & spatial neglect (no spatial
understanding)
3. Temporal – audio processing
Portion of temporal cortex known as “Wernike’s area”
Damage [to Wernike’s area] ???? can’t understand language 4. Occipital – vision (TRICK: same letters as “optical”)
Job: converts light from your eyes into your “rick subjective percept”
The Endocrine System:
Endocrine System = a communication network that uses hormones to influence thoughts, behaviors, & actions
Hormones = chemical substances released into the bloodstream by the “ductless endocrine glands” (pancreas, thyroid & testes/ovaries)
Hormone organs (and location):
Pineal, Hypothalamus & Pituitary (brain)
Thyroid & Parathyroid (neck-region)
Thymus (upper chest)
Adrenal & Pancreas (midsection)
Ovaries & Testes
Gonads = Endocrine glands that influence sexual behavior
Gonadal hormones: generally the same in males & females but… Androgens (testosterone) = prevalent in males
Estrogens (estradiol, progesterone) = prevalent in females Pituitary gland (“master gland”) = tells your body to release hormones from the rest of the endocrine glands that are responsible for major bodily processes
2) Peripheral Nervous System = EVERY OTHER NERVE CELL IN THE BODY 2 main components:
1. Somatic Nervous System = transports sensory signals from skin, muscles & joints to/from the central nervous system
2. Autonomic Nervous System = regulates the inside of the body by stimulating glands and internal organs & transports their signals to the central nervous system Sympathetic division = prepares the body for action (fight or flight)
Physical examples: dilates pupils, relaxes lungs, accelerates & strengthens heartbeat, suppresses bowl movement, contracts vessels
Parasympathetic division = returns body to normal resting state Physical examples: contracts pupils, constricts lungs, slows heartbeat,
activates bowl movement, dilates vessels
Both systems control most internal organs, but increased anxiety ???? sympathetic dominance
How the Brain Changes:
Brain is malleable
Plasticity = a property of the brain that allows it to change as a result of experience, drugs, or injury
Reflects the relationship between our biological & environmental influences The biological basis for learning
These changes usually strengthen preexisting connections
Hebb’s “fire together, wire together” catchphrase: “When 2 neurons fire simultaneously, the synaptic connection between them strengthens”
New connections can form between neurons – learning (in general) usually causes connections to break
Synesthetes:
Synesthesia = sensory experiences are crossed for synesthetes
One sense is used to stimulate another sense in the body
Neuroplasticity is not just about making new neural connections, but pruning preexisting ones
Lecture 4/Chapter 5 – Perception
Sensation & Perception
Sensation = detection of the nervous system
Perception = brain processing
The brains processing of detected signals results in internal representation of the stimuli that form a conscious experience of the world
Qualitatively & Quantitatively
The brain needs both info about the stimulus
Qualitative – what is the identity of the signal?
Quantitative – how much of the signal is there?
How to measure perception:
Psychophysics = A subfield of psychology that measure the relationship between stimuli & perception, examining our psychological experiences of physical stimuli Often interested in assessing thresholds of perceptual abilities
2 types of thresholds:
1. Absolute threshold = the minimum intensity of stimulation required before someone experience a sensation
Ex: the absolute threshold for hearing is the faintest sound a person can
detect (usually a dog whistle)
2. Difference threshold = the minimum amount of change required for someone to detect a difference (the “just noticeable difference”)
Weber’s Law = the “just noticeable difference” between 2 stimuli is based on a proportion of the original stimulus rather than on a fixed amount of difference
Primary modes of sensation:
1) Taste
Gustation = the sense of taste
Taste buds = sensatory organs, mostly on the tongue
Stimulated taste buds send signals to the brain which produce taste
Disclaimer: different regions of the tongue are NOT sensitive to certain tastes Every taste experience is composed of a mixture of 5 basic qualities: sweet, sour, salty, bitter, & umami
2) Smell
Olfaction = the sense of smell
Literally a linking of molecules to specific receptors, each with their own unique identity. Works like a ‘lock (receptor) and key (odorant molecule)’.
Humans have ~900 receptors!
Process:
1. Odorant molecules pass into the nose & nasal cavity
2. They contact a layer of tissue embedded with smell receptors (= olfactory epithelium) 3. Smell receptors relays info to the olfactory bulb, which begins the perceptual processing of smell and sends it to the rest of the brain
3) Touch
Haptic sense = conveys sensations of temperature, pressure, pain, & and the localization of our limbs in space
Receptive field = region in space that a sensory neuron is sensitive to
Parts of the body are more sensitive to touch than others
Ex: fingers are more sensitive to touch than your calf
Pain is part of a warning system that prevents you from continuing activities that may harm you
2 kinds of nerve fibers have been identified for pain:
1. Fast fibers for sharp, immediate pain; activated by strong physical pressure & high temperatures
2. Slow fibers for chronic, dull, steady pain; activated by chemical change in tissue when skin is damaged
4) Hearing
Audition = the sense of sound
When objects vibrate, air molecules are displaced, producing a sound wave which are converted into brain activity (change in air pressure that travels through the air)
Ear decomposes sound before it’s processed by the brain
Amplitude = quantity of sound wave ???? determines loudness
Frequency = quality of sound wave ???? determines pitch
The cochlea (part of the ear) is arranged tonotopically (= it codes frequency as a function of distance across the cochlea)
There are little hairs in the cochlea that vibrate with sound; they vibrate differently to different frequencies (differ in rigidity)
The mechanical vibration is transduced into a neural response
Frequency insensitivity = when the hairs break from being exposed to a strong frequency intensity
5) Vision
Most of the scientific study of sensation and perception is concerned with vision *images are inverted when first seen by the eye
Parts of the eye (in order of operation):
Pupil = determines how much light gets through
Iris = controls the size of the pupil
Cornea = focuses the incoming light
Lens = focuses the light to project and upside-down image on the retina
Retina = transduces the light into a neural response and disperses that signal to the rest of the brain through the bundle of axons (optic nerve)
Contains 2 types of receptor cells that have photopigments (initiate the
transduction of light waves into electrical neural impulses:
1. Rods = respond to very low levels of light like night vision;
located at the outer edges of the retina
Important for peripheral vision
2. Cones = respond to high levels of light and for color & detail;
located heavily near ‘fovea’
Sensation to Perception:
*All sensory info first given to the thalamus (except olfaction)
Perceptual processes really begin in the cortex
Hearing:
Auditory neurons in the thalamus extend their axons to the primary auditory cortex Sound Localization = the spatial identification of a sound source based on subtle in time it takes for a sound to hit each ear; localizations is processed in the auditory cortex Cocktail party effect = selective listening
Vision:
Very little ‘seeing’ actually takes place in the eye
Vision is a result of constructive processes that occur throughout much of the brain Primary Visual Cortex (VI) = transforms light on the retina into psychologically relevant info
Contains a retinotopic map of the visual scene
Orientation selectivity = when our visual system detects edges (one of first things)
Filled with detectors that are sensitive to edge orientation, each giving certain info about the visual scene
Process: Light pixels ???? edges ???? contours ???? shapes ???? objects!
2 parallel visual processing pathways:
1. Dorsal Stream (where): spatial perception
2. Ventral Stream (what): perception & object recognition Some cortical regions are sensitive to facial expression & gaze direction Perceptual constancy = the brain views objects as constant despite sensory info that might lead it to think otherwise
The brain computes a ratio based on relative magnitude rather than on sensations’ absolute magnitude
Colors don’t usually appear in isolation, rather in a scene
Color Contrast = the effect when one color differs from another color near it