Psychology Study Notes PDF

WEEK 3 - Research Methods 2 types of variables - Variable -> a quality that differs and can take different values for different people - Independent variable -> a variable that is expected to influence the other variable (Etc. experimenter manipulates to see effects on the independent...

WEEK 3 - Research Methods 2 types of variables - Variable -> a quality that differs and can take different values for different people - Independent variable -> a variable that is expected to influence the other variable (Etc. experimenter manipulates to see effects on the independent variable) - Dependent variable -> the variable that is influenced by the independent variable (i.e, always what we measure) - Manipulation Hypothesis Is the hypothesis testable? ○ Ex. People who laugh more have lower levels of anxiety than people who laugh less Research designs - Naturalistic observations - Case studies - Experimental - Correlational Naturalistic observations Studying behaviours in “real world” settings as they naturally occur with no attempt to study (Ex. Advantages: ○ We can understand a range of behaviours as they naturally occur ○ We can measure “true” behaviours ○ Avoids social desirability bias ○ High in external validity Disadvantages: ○ Slow progress ○ Low in internal validity (Unable to make cause and effect conclusions) ○ If people are aware of being observed Case Studies In-depth examination of the life of one person Interviewing the person or people that know them, analysing writings, etc Advantages: ○ Researchers are able to find out about personality in great detail ○ Formulate a general hypothesis that can be tested on a larger sample ○ In-depth knowledge about a rare phenomena  Disadvantages: ○ Results can never be generalised ○ Cannot establish causality *The only research that can create cause and affect studies are experimental studies Experimental methods Used to determine causality -> whether one variable (independent variable) causes another (dependent) variable I.e whether a drug (independent) variable causes memory enhancement (dependent variable) Placebo effect - Whenever there's a change in someone's behaviour simply because someone is expecting a change (Latin phrase: “I shall please”) - (EXPECTATION OF GETTING BETTER) Experimental group (drug) (testing effects) Control group (no drug) - no manipulation (to see the effect that hasn’t been manipulated) Placebo control group sugar pill (Placebo) - Placebo effect (to make sure the study is not influenced by the placebo effect Nocebo effect -> “to harm” (EXPECTATION OF HARM) Harm resulting from the mere expectation of harm (Opposite of placebo effect) Between-subject Design Needs to meet 2 key requirements: ○ 1. Random assignment of participants to conditions -> Manipulation across groups ○ 2. Manipulation of an independent variable -> Random assignment (randomization) Does a drug (Independent variable) cause memory enhancement (dependent variable)? Within-Subject Design 2 Key requirements: ○ 1. Manipulation of independent variable(s) -> manipulate within group ○ 2. Ensuring equality between participants in the different experimental conditions -> counterbalancing Experimental methods Random selection vs. random assignment Blind and double-blind studies Blind -> Being unaware whether one is in the experimental or control group ○ Avoid the placebo effect Double-blind -> neither researchers nor participants are aware of who is in the experimental or control group  Experimenter expectancy effect or rosenthal effect ○ Unintentional (When the tester unintentionally influences the study) ○ Confirmation bias Experimental methods cont’d Advantage: ○ Can establish relationships between variables Disadvantages: ○ Cannot identify relationships between variables as they occur naturally in everyday life - Cannot study behaviours as they naturally happen from a participant because of changes in setting, etc ○ May be impractical or unethical in some cases ○ Demand characteristics (Participants guess what the goal of the study) Telling participants a Cover story in order for the participant not to know what the goal of the study is “Distractor” tasks or “filler” Correlational studies Determining whether there is a relationship between two variables, without manipulation/intervening in any way Examines the relationship between variables as they occur naturally Correlation coefficient (-1 to +1) 0 means no relationship exists Positive correlation - As self-esteem decreases, happiness decreases - As self esteem increases, happiness increases Negative correlation - As self esteem increases, happiness decreases - As self-esteem decreases, happiness decreases Summary of Correlational studies Is there a relationship between self-esteem and happiness? - Strong “+” relationship between self esteem and happiness - Moderate “+” relationship between self esteem and happiness - Weak “-” relationship between self esteem and happiness Absolute value is the number Correlation studies Advantages: ○ Examines the relationship between variables as they occur naturally (no manipulation involved)  Disadvantages ○ Not designed to identify causal relationships (Directionality problem; third variable problem) *correlation does not indicate causation When to use which method? Each design has strengths and weaknesses that make it more/less suitable for specific research questions The research design choice depends on the research question and the goals of the research Strength of one design may be the weakness of another Provide complementary methods for exploring human personality Class activity Research question: Are individuals with AUD less happy compared to individuals without AUD Goal: To generalise our findings to all who have AUD YOU CAN USE CORRELATIONAL STUDIES TO DETERMINE THIS Ethical concerns REB - Research Ethics Board Must weigh scientific knowledge over potential harm to subjects Informed consent ○ Informed consent gives: Duration of the study Potential risks and discomfort Volunteer participation and right to withdraw Debriefing - is a process which the researchers tell the participant exactly what happened Decception ○ Deception is justified only when: Can’t perform without the deception Use of deception doesn't negatively affect the rights of the participant Research does not involve a medical or therapeutic intervention *Debriefing is emphasised when a study uses deception Statistics Descriptive statistics Inferential statistics Descriptive statistics Describe data Central tendency -> measure of the “central” scores in a dataset (where the group tends to cluster) Mean (Average) number of participants (5):  ○ 78 + 110 + 78 + 100 + 94 / 5 = (92) Median (which number falls in the middle): ○ 78 78 94 100 110 (94) Mode: ○ 78 Descriptive statistics FIRST PIC: MEAN SECOND AND THIRD PIC: MEDIAN OR MODE OUTLIERS SCORE OUTSIDE OF THE OTHER SCORES Descriptive statistics cont’d Variability Range -> difference between the highest and the lowest scores Standard deviation -> the average amount that an individual data point differs from the mean Inferential statistics (How confident we can be to generalize everyone in the population) Statistical significance -> the probability of obtaining our finding merely by chance is small Individuals with ASD have more cortical folding than individuals with ADHD (p nerve cell specialised for communication ○ 86,000 neurons in the brain Intercellular communication -> Each neuron makes tens of thousands of connections with other neurons ○ 160 trillion connections in the brain The subcomponents of the neurons Cell body (soma) -> contains the nucleus Nucleus -> manufactures proteins Dendrites -> receive information (or signals) from other neurons, & pass it to the cell body Axons -> sends the information (or signal) to other neurons Steps of Signal transmission Spherical sacs containing neurotransmitters chemical messengers neuron use to communicate with each other 3. Axon terminals release neurotransmitters into a gap (synapse) through which information is exchanged between neurons (i.e, received by receptors of the dendrites of nearby neurons) *VIDEO on steps of signal transmission: 2 minute neuroscience synaptic transmission Reuptake -> a means of recycling neurotransmitters Receptor sites -> Locations that uniquely recognize a neurotransmitter (Receptor sites are specialised only certain types of neurotransmitters) Neurotransmitters *The most common (in CNS) Glutamate ○ Excites neurons (increases the odds that they will communicate with other neurons) ○ Associated with enhanced learning & memory ○ However, if too elevated -> may continue to psychological disorders (i.e, schizophrenia) GABA (Gamma-aminobutyric acids) ○ Inhabits neurons (decreasing neural activity) ○ Certain drugs bind to GABA to treat anxiety, insomnia, depression, & epilepsy Neurotransmitters cont’d Monoamine neurotransmitters ○ Norepinephrine ○ Dopamine Motivation & rewarding experiences that occur when we seek out or anticipate goals ○ Serotonin Ex. Psychoactive medication (drugs) Myelin Sheath Myelin Sheaths speed the transmission of electrical signal down the length of the axon Nodes -> gaps along the axons (electrical signal does not stop between the nodes) Myelin sheaths are created by oligodendrocytes which are a type of glial cells ○ Which are a type of glial cells Damage to myelin can disrupt the efficiency of signal from travelling down the axon -> physical or emotional symptoms (i.e, multiple sclerosis) How much of our brain do we use? The 10% myth Neuroimaging studies -> All brain regions become active on brain scans at one time or another: ○ When engaging in different activities & generating different thoughts, feelings, or perceptions ○ Even at rest, brain activity continues (i.e., not engaging in an activity) Losses of small regions of certain parts of the brain can cause permanent losses of functions or show subtle changes in behaviour Major Structures of The Brain Different brain regions serve different functions ○ Which interact with one another to generate our thoughts, feelings & behaviour The brain is a highly interconnected web of networks and circuits Cerebral cortex Outermost layer of the brain Gyrus (fold) & sulcus (groove) Folds are not random! Every healthy human brain has similar folds & grooves on the cortex Specialised functioning -> analyses sensory information & higher brain functions Cerebral Hemisphere 2 hemispheres: ○ Right hemisphere ○ Left hemisphere Corpus callosum -> large bundle of fibres connecting the 2 cerebral hemispheres Lateralization -> cognitive functions that rely more on the hemisphere than the other Brain produces a crossing over for movement The cerebral cortex 4 lobes: ○ 1. Frontal lobe ○ 2. Parietal lobe ○ 3. Temporal lobe ○ 4. Occipital lobe Frontal lobe Performs executive function that coordinates other brain areas (motor planning, language, decision making, reasoning, judgement) Central Sulcus -> sulcus that separates the frontal lobe from parietal lobe Motor cortex -> responsible for voluntary body movement Prefrontal cortex -> responsible for thinking, planning, language Broca’s area -> responsible for speech production Parietal lobe Touch & perception Primary sensory cortex -> sensitive to touch (pressure, pain, temperature); receives information about sensations Spatial perception -> Track objects’ locations and shapes, guides our attention when we want to act Hemispatial neglect Temporal & occipital lobes Temporal lobe: hearing, understanding language, & memory Auditory cortex - allows us to recognize words and the sounds Wernicke’s area -> responsible for understanding speech Fusiform face area Occipital lobe contains the visual cortex Subcortex Structures Basal ganglia -> help to control movement Limbic system -> “emotional centre” of the brain ○ Thalamus ○ Hypothalamus ○ Amygdala ○ Hippocampus Limbic system Thalamus -> sensory relay station Hypothalamus: ○ Responsible for regulating and maintaining bodily states by influencing hormone levels ○ Oversees hormone release and autonomic nervous system ○ Plays an important role in motivational behaviour (helping to regular hunger & thirst)  Amygdala -> responsible to modulate memories based on feelings ○ Pays attention to emotionally impactful stimuli and helps us remember wheat triggered our emotions ○ Fear is the most studied emotion ○ Hippocampus -> responsible for conscious memories for facts, events, and spatial memory Cerebellum “Little brain” Our sense of balance Helps us coordinate movement Helps us learn motor skills Brainstem Contains 3 parts: ○ Midbrain ○ Pons ○ Medulla Brainstem: Midbrain Movement Tracking of visual stimuli Reflexes triggered by sound Brainstem: pons Triggering dreams Connects the cortex to the cerebellum Brainstem: medulla Regulates basic vital functions: ○ Heartbeat ○ Breathing ○ Etc. Controls nausea and vomiting Serious damage to the medulla can cause brain death Grey matter and white matter Gray matter (or cerebral cortex): contains cell bodies and dendrites of neurons (appear darker) White matter: contains axons and myelinated sheaths (appears lighter) Protection against injury Cerebrospinal fluid (CSF): ○ Cushions the brain against injury ○ Contained in the cerebral ventricles Meninges: ○ Thin layer of membranes around the brain and spinal cord Neuroplasticity Ability of the brain to change over time ○ In response to learning, treatment, or damage Possible ways neuroplasticity can occur: ○ Creating new synapses -> synaptogenesis ○ Strengthening existing synaptic connections ○ Structural neuroplasticity -> change in the shape of neurons, or number of dendrites Neuroplasticity cont’d Synaptogenesis -> formation new synapses Pruning (synaptic pruning) -> death of neurons and retraction of axons to remove connections that are not useful ○ Fine-tuning of neural connections -> “use it or lose it” notion during early childhood Pruning streamlines neural organisation, enhancing communication between brain regions Myelination -> axons are insulated by myelin sheaths Neuroimaging techniques Different neuroimaging techniques can be used to study: ○ Brain structure and anatomy ○ Brain activity ○ Brain connectivity MRI scans Advantage: Non-invasive procedure Brain structure and brain function (FMRI) can be studied Disadvantage: ○ Very loud ○ Enclosed space PET scans Measures brain activity Radioactive substance is injected Disadvantage: invasive procedure due to radioactive substance Brain stimulation techniques Deep brain stimulation (DBS) -> neurosurgical procedure that implants electrodes within the brain to provide direct electrical stimulation Transcranial Magnetic Stimulation (TMS) -> Strong magnetic fields applied to the skull to enhance or interrupt brain function ○ Non-invasive Behavioural Genetics methods A scientific approach which examines the influence of nature and nurture on psychological traits  Heritability -> percentage of variability in a trait across individuals that is the result of genes Phenotypic variance -> observed individual differences (i.e., height or personality) Genotypic variance -> individual differences in total collection of genes possessed by each one of us Behavioural Genetics methods cont’d Nature-nurture debate Teasing apart the contribution of genes and the environment: ○ Family studies ○ Twin studies ○ Adoption studies Family studies If a trait is highly heritable … family members with greater genetic relatedness should be more similar to each other than family members who are less closely genetically related But.. family members also share the same environment Thus, findings from family studies are never definitive Twin Studies Two types of twins: Monozygotic (MZ) and dizygotic (DZ) Estimates heritability by examining whether identical twins are more similar to each other, than fraternal twins are, in any personality trait or physical characteristic If identical twins are more similar than fraternal twins, this provides evidence of heritability Adoption studies Examines environmental influences Examines genetic influences