PSYC 1020 Midterm
Lecture 2
- What is psychology?
o Scientific study of human mind and behaviour
o From Greek:
§ Psyche = soul/mind
§ Logos = study
- Science
o Empirical method of answering questions
o Pursuit of knowledge through systematic observation
§ Phenomena are measures/quantified
§ Theories are tested/falsified
§ Results are replicated/verified
§ Knowledge is updated/revised
- Psychological findings are probabilistic/statistical
o Show generalized trends about group of people
§ What is more likely to happen
§ What is typical of most people
§ NOT about specific individuals
o But also acknowledge individual differences
§ Some people differ from trend/average
§ When, for whom, why?
- Behaviour
o Observable actions
§ What people say, do, gesture, express
o Can be intentional or automatic
- Mind
o Inner mental experiences
§ Perceptions, feelings, thoughts, beliefs, memories, dreams -> consciousness
o Private, subjective
o Not same as brain, but inter-connected
- Mind-brain connection
o Mental events = unique patterns of neural activation distributed throughout the brain
o Everything psychological is biological
- Historical roots of psychology
o Philosophy
o Physics and physiology
o Theories, questions
§ Mind vs. body, nature vs. nurture, perceptions vs. reality
o Scientific methods
o Empirical evidence
- Psychophysics
o German scientists (G. Fechner, H. von Helmholtz)
o Used experimental methods to measure how physical stimuli relate to psychological sensations and perceptions
o Showed that mental events could be studied using scientific method
- Founding of psychology discipline
o Who – Wilhelm Wundt
o Where – Leipzig, Germany
o When – 1879
o 1st uni course, textbook, lab in experimental psychology
o Applied scientific method to study “facts of consciousness”
- Structuralism
o Earliest school of thought in psychology
o Influenced by Wundt, psychophysicist
§ Proponent – Edward Titchener
§ Question – what is consciousness like?
§ Goal – basic structure and elements
§ Studied – static mind disassembled, isolated
- Functionalism
o Emerged as counterpoint to structuralism
o Influenced by Darwin’s theory of evolution
§ Proponent – William James
§ Question – why is consciousness like it is?
§ Goal – adaptive functions, purpose
§ Studied – mind in action as a whole, in context
o Questions
§ Why is our attention limited, why is our thinking sometimes biased, why is our memory selective, why do we feel emotions, why do we conform to what others do?
· Evolutionary adaptions, facilitate effective functioning, survival, reproduction
- Perceptions are illusions, not strict reality
o M. Wertheimer demonstrated Phi Phenomenon
o When 2 stationary images are presented in rapid succession, they are perceived as movement of one image
- Gestalt psychology
o Raw inputs from environment are processed holistically – the whole is other than the sum of its parts
o Brain used “educated guesses” to organize sensory inputs together and make meaningful extrapolations
§ Brain is a predictive, meaning-making machine
§ Consciousness is constructed experience
- What became of structuralism and functionalism
o Historical schools of thought
o Superseded by newer perspectives
o Both structural and functional questions are still relevant
- Current perspectives
o Evolutionary
o Genetics
o Neuroscience
o Cognitive
o Psychodynamic
§ Behaviour is influenced by the unconscious conflicts/motives of which we are unaware
§ Unconscious(id)
· Unacceptable memories, desires, instincts
§ Repression and defenses
· The id content is mentally hidden from consciousness
§ Psychoanalysis
· Uncovering symbolic meaning in the leaked id content
· Self-insight is therapeutic
o Behavioural
§ Behaviour is learned through experience
§ Focus on observable behaviours
§ Causal role of environment
§ Focus on experimentation
o Social-cultural
- Operant conditioning
o Behaviour changes in response to consequences
§ Reinforced behaviours will be repeated
§ Punished behaviours will be avoided
- Classical conditioning
o When 2 stimuli co-occur together, our automatic response to one stimulus gets transferred onto the other
- What became of behaviourism
o Still influential, but criticized for:
§ Ignoring biological preparedness (evolution, genetics)
§ Ignoring mental processes (perceptions, cognitions)
- Cognitive perspective
o We do not respond to actual events, we respond to our subjective construal = what we make of the events
o Focus on info processing by the mind
- System of thought
o Controlled – conscious, deliberate, effortful, slow and taxing
o Automatic – unconscious, simple, unaware, fast and frugal
- What became of cognitive perspective
o Still influential but criticized for being overly “individualizing”
§ Implies that “it’s all in a person’s mind” (overlooks systemic/societal influences)
§ Downplays the embeddedness of individual perceptions within shared sociocultural beliefs
- Social and cultural perspectives
o Thoughts, feelings and behaviours are influenced by the presence of other people – actual, imagined, implied
o We are often unaware of situational influences – underestimated their effects
- Perspectives are complementary
o Behaviours/experiences are the product of multiple influences
o Multiple perspectives are necessary
§ Each perspectives adds a unique piece of knowledge
§ No single perspective is sufficient
- Biopsychosocial model
o Integrative view of a complex system
o 3 levels of interacting influences on mind and behaviour
§ Psyc - Unconscious, conditioning, cognitions
§ Social – environment, other people, culture
§ Bio – brain, physiology
Lecture 3
- Scientific process
o Theory – proposed explanation
o Hypothesis – testable prediction
o Test – structured observation, operational definitions
§ Theory is supported or revised after test
- Theory
o Set of proposed explanations for psychological phenomena
o Tentative ideas about, what, when, why, how
o An educated guess based on past observations
o General sense, not a comparison or opinion but can be proved with scientific method
- Hypothesis
o A specific prediction of what should (and shouldn’t) happen if the theory is correct
o Derived from theory
o Must be testable and replicable
o Specific enough to collect data, derived from theory
§ Eg. The more youth use social media, the less happy they feel
§ Caveat – is it specific? Testable? Replicable?
- Operational definition
o Precise way of measuring (or controlling) each variable
§ Properties and instruments
o Way of quantifying variability in experiences
o Make hypothesis specific, testable, replicable
- How to op. define happiness?
o Dictionary definition – a state of wellbeing and contentment
o Op. definition - ? number = level of happiness
- Challenge in psyc measurement
o Many psychological variables are “constructs”
§ Abstract, not directly observable
o Must be inferred from indirect indicators
§ Op. definitions are approximate, not perfect
o Same construct can be op. defined in multiple ways
§ Eg. Behaviours, physiology, self-reports
§ Each measures has pros and cons
- Good measure is both..
o Reliable – yields consistent observations (precision)
o Valid – actually measures what you intended (target)
- Op. defining “happiness”
o Frequency of smiles in a given time period
o Based on behaviours rated by observers
§ Pros/cons – people smile for different reasons, may be nervous or happy
o Proportion of positive mood states on a given day
o Based on hourly mood ratings on mood app
§ Pros/cons – people may not be telling truth, results could be consistent with validity, timing matters
o Score of satisfaction with life scale
o Based on self-report questionnaire
- Research designs
o Broad template for designing research studies
o Different designs serve different goals
§ Choose most appropriate for the research question
o Each design has pros and cons
§ No single design is the best
- Types of research designs
o Correlation
§ Goal – predict
§ Allows to combine variables together
o Experimental
§ Goal – explain
§ Know if it is a reliable relationship
o Descriptive
§ Goal – describe
§ Gather lots of information
· First research strategy used by scientists
- Descriptive research
o What are the characteristics of a particular phenomenon
§ Eg. Prevalence, features, duration, frequency
o Measure/observe people’s existing behaviour
o Unobtrusively, NO manipulation by researcher
§ Can describe the phenomenon
o One variable at a time (NOT linking variables together)
- Evaluating
o Utility
§ Can study behaviours as they naturally occur
§ Can collect rich description of particular phenomena
§ Can generate novel research questions
o Limitations
§ Can only describe one phenomenon at a time
§ Can NOT test hypotheses about relationships or causes
§ Can NOT rule out alternative explanations
- Correlational research
o Is there a systematic, naturally occurring relationship between 2 or more variables?
o Measure/observe people’s existing behaviours
o Unobtrusively, NO manipulation by researcher
§ Can describe both phenomena
§ PLUS can predict one variable from the other
- Procedure
o Measure the variable as they are (no manipulation)
o Compute correlation coefficient between them
o Interpret what something may mean
- correlation coefficient (r)
o statistical index of relationship between 2 variables
o indicated if and how 3 variables are related to each other
o ranges from -1.0 to +1.0
o two pieces of info
§ direction
· positive
o 2 variables vary in the same direction
o More of one co-occurs with more of the other
o Less of one co-occurs with less of the other
· Negative
o 2 variables vary in opposite direction
o More of one co-occurs with less of the other
§ Strength
· Magnitude ranges from 0-1
· Higher values close to 1 indicate stronger link
· Lower values close to 0 indicate weaker link
- Evaluating
o Utility
§ Can study a wide range of variables
§ Can identify potential causes
o Limitation
§ Can NOT demonstrate cause-and-effect
§ Correlation does not imply causation
- Third variable problem
o An unmeasured extraneous factor may affect variables
- Experimental research
o Do the manipulated differences in the independent variable
o Lead to the predicted changes in the dependent variable
o With all else being controlled
§ Can infer causation
§ Can rule out alternative explanations
- Key features of experiment
o Manipulation of IV
§ Create 2 groups that are identical except for IV
§ Change/vary the IV between groups
· To isolate the causal effect of IV
o Random assignment
§ Participants must have equal chance of being in either group
· Eliminates self-selection effects
· Controls for pre-existing differences
· Groups start off roughly equal on everything
o Measurement of DV
§ Measure DV for all participants
§ Compare experimental vs. controlled group
- Utility of experimental research
o Can draw causal conclusions
- Internal validity
o Can the change in DV be attributed to the manipulation of IV and nothing else?
§ Threats
· Lack of control group
· Lack of random assignment to groups
· Poor control over confounding 3rd variables
§ Correlation studies have low internal validity
- External validity
o Can the observed effects be generalized to real-world behaviours and people?
§ Threats
· Unrepresentative participants
· Unrealistic op. definitions of IV or DV
· Contrived testing conditions
· Short-term effects
· Ethical constraints or manipulation
- Principle of converging operations
o Necessary trade-off between internal and external validity
o Each method/study has its own limitations
o A single study cannot account for all variables
o Causes of behaviour are complex and multiple
o Converging evidence across multiple methods/studies increases confidence in conclusions/theory
Lecture 4 + 5
- Nervous system
o Handles info processing
o Interacting network of billions of neurons
o Sending electrochemical signals throughout the body
o Translate into sensations, feelings, thoughts, actions
- Organization
o Nervous system
§ Central
· Brain
o Directs mental processes
o Regulates basic life functions
· Spinal cord
o Relays info between brain and PNS
o Controls spinal arc reflexes
§ Peripheral
· Nerve connecting CNS to organs and muscles
o Somatic
§ Voluntary actions
§ Conveys sensory info to CNS
§ Passes commands from CNS to skeletal muscles
o Autonomic
§ Involuntary/automatic bodily functions
§ Passes CNS commands to blood vessels, internal organs, glands
· Parasympathetic
o Rest and digest
· Sympathetic
o Fight or flight
o
- Spinal cord injury
o Different spinal nerves connect different parts of the body to the brain
o Above injury
§ Intact paths and normal functioning
o Below the injury
§ Severed paths and loss of functioning
- Neural communication
o 2 types of cells in nervous tissue
§ Neurons
· Specialized nerve cells
· Receive and transmit info
· 3 basic parts
o Cell body
o Several dendrites
o One axon
§ Glial cells
· Support/helper cells for neurons
· Nutrition, maintenance, protection
· Insulation (myelin)
- Parts of neuron
o Soma
§ Cell body
§ Keeps the neuron alive
§ Synthesizes neurotransmitters
§ Coordinates info
o Nucleus
§ Contains chromosomes with our DNA
o Dendrites
§ Branching extensions off the soma
§ Covered in synapse receptors
§ Receive info from other neurons
§ Pass info to the soma
o Axon
§ Elongated fiber off the soma
§ Conducts info away from the soma
§ To other neurons, muscles, glands
o Myelin sheath
§ Insulation around (some) axons
§ Made by glial cells
§ Speeds up signal travel
o Axon terminals
§ Knob-like endings, end at synapse
§ Contain vesicles with neurotransmitters
§ Carry over info to other neurons/cells
- Action potential
o Conduction of signal within a neuron
o Electrical signal that sends info along the axon
o Triggered if total strength of all incoming signals from dendrites exceeds a firing threshold
o All or none action
- Neuron membrane
o Resting potential – polarized
o Action potential de- the re-polarized
o Refractory period – hyper-polarized
- Demyelinating disease
o Damaged myelin sheath
§ Slow/distorted neural signals
§ Axon deterioration/loss
§ Neurological problems
· Movement, sensation, cognition, internal organs
· Eg. Multiple sclerosis
- Synapse
o Microscopic junction between axon terminals of the sending neuro and dendrites or soma of the receiving neuron
o Transmission of signal between neurons
- Neurotransmitters
o Chemical messengers that carry the signal across the synaptic gap
o Excitatory
§ Boost the signal
§ Higher likelihood of new action potential
o Inhibitory
§ Dampen the signal
§ Lower new action potential
- Synaptic transmission
1. Action potential stimulates release of neurotransmitters from vesicles into the synaptic gap
2. Neurotransmitters bind to matching receptor sites on the receiving neuron
a. Boost or inhibit likelihood of a new action potential
3. Neurotransmitters are cleared from the synapse
a. Bind to autoreceptors on the sending neuron
b. Reuptake back into sending neurons
c. Broken down by enzyme in the synapse
d. Diffuse out of the synapse
- Types of neurotransmitters
o 100s of chemical, act withing different regions of NS
o Have different, multiple effects on mind and behaviours
o Common
§ Endorphins, dopamine. Norepinephrine, serotonin, glutamate, GABA, ACh
- Psychoactive drugs
o Alter neurotransmitters activity in synapse
§ Agonists
§ Antagonists
o Various mechanisms of action via;
§ Synthesis, receptor binding, release, reuptake
- Direct agonists
o Imitate/mimic the action of NT
o Bind to same receptor sites
o Activate them -> produce same effect
§ Eg. Opioids are direct agonists for endorphins
- Indirect agonists
o Enhance action of NT
§ Increase synthesis
§ Stimulate release
§ Block reuptake/removal
o More NT in synapse for longer to bind to receptors
§ Stronger, longer effect
o Eg. Stimulants are indirect agonists for dopamine and norepinephrine
- Direct antagonists
o Prevent the action of NT
o Bind to the same receptor sites
o Do not activate them – block effect
- Indirect antagonists
o Inhibit action of NT
§ Decrease synthesis
§ Prevent release
§ Speed up removal
o Less NT in synapse available to bind to receptors
§ Weaker, shorter effect of NT
- Structure of the brain
o Bottom to top
§ Basic life functions at lower levels
§ Complex functions at higher levels
§ All parts interact together
Lecture 6
- Perspectives on learning – relatively enduring change in behaviour/knowledge that’s acquired through experience
o Social-cultural – observational
o Cognitive – memory
o Neuroscience – neuroplasticity
o Evolutionary – preparedness
o Behavioural – associative
- Behaviourism
o Premise 1
§ Exclusive focus on observable behaviour (NOT the mind)
· In opposition to introspection, psychoanalysis
o Objective measurement
o Experimental manipulation
o Study animals as analogues
o Premise 2
§ All behaviour is learned through interactions with the environment
· In opposition to genetic determinism
o Born as tabula rasa (clean slate)
o Stimulus-response relationships
o Prediction and control of behaviour
- Associative learning (conditioning)
o Learning that 2 events are linked together
§ Behaviours -> operant conditioning -> consequences (reinforce vs. punish)
§ Antecedents (US + NS) -> classical conditioning -> behaviours
- Classical conditioning
o Learning to associate two antecedent stimuli
o Applies to automatic involuntary responses
- Ivan Pavlov
o Russian physiologist, early 1900s
o Studied digestion in dogs
o Gave dogs meat powder and measured amount of saliva
o Assumed contact with food was required to trigger saliva reflex
- Pavlov’s discovery
o Dogs started to drool before contact with food
o Triggered by mere smell, sight of bowl, feeder’s footsteps
o Signals associated with food
o Psychological process (learning)
- Pavlov’s experiments
o Systematically paired food with other neutral stimuli
§ Metronomes, lights, bells
o After several pairings, these stimuli would trigger drooling even in the absence of food
§ Stand in signals for food
- Before conditioning
o Unconditioned stimulus (US)
§ Natural trigger that reliably produces UR (not learned)
o Unconditioned response (UR)
§ Natural reflexive reaction to US (not learned)
o Neutral stimulus
§ Initially elicits NO relevant response by itself
- During conditioning (acquisition)
o US + NS = UR
o Repeated pairings of NS with US create an association
- After conditioning
o Conditioned stimulus (CS)
§ LEARNED trigger for CR
o Conditioned response (CR)
o LEARNED response to CS in the absence of US
- Rules of CC
o Response = behaviour/reaction; stimulus = trigger/event
o US naturally produces a response
o NS initially elicited no relevant response by itself
§ NS becomes CS as result of pairing with US
o NS = CS always
o CR is similar to UR (maybe weaker)
§ UR becomes CR when it is in response to CS
- Second-order conditioning
o When a previously conditioned CS and its CR become associated with a new NS, turning it into a secondary CS
- Case of “little albert”
o Watson and Rayner (1920) conditioned an infant to fear a rat by repeatedly pairing the rat with a loud noise
§ US -> UR + NS = CS -> CR
- Stimulus discrimination
o When CR is not generalized to other similar stimuli
- Extinction
o When CS is repeatedly experienced alone (no pairing with US), it will gradually stop eliciting CR
§ CR can be suppressed
o BUT: watch out for spontaneous recovery of CR after a rest period (even without additional pairings of CS + US)
§ CR can be weakened, but not erased
- Cognitive factors in CC
o Rescorla-Wagner model:
§ CC learning is easiest and strongest for NS that is an immediate, unique, reliable and likely predictor of US
· NS has information value
· Key role of expectations
- Biological factors in CC
o Biological preparedness (John Garcia)
§ Some CRs are learned from a single pairing of NS + US
§ Certain associations are easier to CC because they have survival value
· Evolutionary adaptation
- Operant conditioning
o Learning to associate behaviour when its consequences
§ Behaviour changes in response to consequences
o Applies to voluntary, proactive responses
§ Eg. Choices, habits, skills, complex behaviour patterns
- Thorndike’s Law of Effect
o Behaviours followed by satisfying/wanted consequences will be strengthened (repeated)
§ Reinforcement = satisfying/wanted
§ Strengthens behaviour
- B. F. Skinner
o Pioneered operant conditioning
o Studied effects of reinforcement
o In animals (rats, pigeons)
o In highly controlled environment
§ Operant chamber (Skinner box)
o Disputed existence of free will
- Shaping
o Stepwise process of acquiring complex (unnatural) behaviours
o Via series of successive approximations
o First, reward each small step in right direction
o Then, reward only the final step
- Positive reinforcement
o Increases likelihood of behaviour
o By adding something wanted
§ Eg. Reward, attention, sensory stimulation
- Negative reinforcement
o Increases likelihood of behaviour
o By removing something unwanted
§ Escape, avoidance, stress/pain relief
- Positive punishment
o Decreases likelihood of behaviour
o By adding something unwanted
- Negative punishment
o Decreases likelihood of behaviour
o By removing something wanted
- Reinforcement schedules
o Patterns that define when the correct response is reinforced
§ Produces different rates of:
· Acquisition
· Response
· Extinction
- Fear
o Stimulus -> fear response
§ Acute sense of imminent danger
§ Surge of autonomic arousal
§ Urge to escape
· Facilitates survival (adaptive)
- Phobia
o Stimulus -> same genuine fear response BUT:
§ Excessive/irrational: out of proportion to actual danger
§ Persistence: 6+ months
§ Disabling: impairs daily functioning
· Psychological disorder (maladaptive)