24-25 AP Exam Study Guide

Research Design

  • Random Sample vs. Random Assignment:

    • Random Sample: Used for generalizing findings to a larger population.
    • Random Assignment: Used in experiments to establish cause and effect.

  • Basic Vocabulary:

    • Hypothesis: A tentative explanation that must be falsifiable (able to be supported or rejected).
    • Operational Definition: A clear, precise, quantifiable definition of variables to allow for replication and reliable data collection.

  • Types of Data:

    • Qualitative Data: Descriptive data (e.g., eye color).
    • Quantitative Data: Numerical data, ideal and necessary for statistics.

  • Population vs. Sample:

    • Population: Everyone the research could apply to.
    • Sample: The specific people (or person) chosen for the study.

Research Designs

  • Correlation: Identifies relationships between two variables.

    • Advantage: Useful when experiments are unethical.
    • Disadvantage: Correlation does not equal causation.
      • Directionality Problem: Unclear which variable causes the other (e.g., depression and low self-esteem).
      • Third Variable Problem: A different variable is responsible for the relationship (e.g., ice cream sales and murder rates).
    • Types of Correlation:
      • Positive Correlation: Variables increase and decrease together.
      • Negative Correlation: As one variable increases, the other decreases.
    • The stronger the number, the stronger the relationship, regardless of the positive or negative sign. Correlation cannot be less than or greater than 1.
    • Stronger relationships = tighter clusters on a graph.

  • Experiments: Purposefully manipulate variables to determine cause/effect.

    • Advantage: Only type that establishes cause and effect.
    • Disadvantage: Can be unethical or too artificial.

  • Key Experimental Variables/Groups:

    • Independent Variable: Purposefully altered by the researcher to look for an effect.
      • Experimental Group: Receives the treatment (part of the IV); can have multiple experimental groups.
      • Control Group: Placebo, baseline (part of the IV); can only have 1 control group.
    • Dependent Variable: Measured variable (dependent on the independent variable).

  • Vocab Unique to Experiments:

    • Placebo Effect: Any observed effect on behavior that is caused by the placebo (shows effectiveness of experimental treatment); usually fixed with blinded studies.
    • Double-Blind: Experiment where neither the participant nor the experimenter knows which condition people are assigned to (e.g., drug studies).
    • Single-Blind: Only the participant is blind; used if the experimenter can't be blind (e.g., gender, age).
    • Confound: Error/flaw in the study that is accidentally introduced (confounding variable).
    • Random Assignment: Assigns participants to either a control or experimental group at random, increasing the chance of equal representation among groups and allowing for cause/effect conclusions.

Other Study Types

  • Naturalistic Observation: Observe people in their natural settings.
    • Advantage: Real-world validity.
    • Disadvantage: No cause and effect.
  • Case Study: Studies one person (usually) in great detail.
    • Advantage: Collect lots of information.
    • Disadvantage: No cause/effect.
  • Meta-Analysis: Combines multiple studies to increase sample size and examine effect sizes.

Statistics

  • Descriptive Stats: Show the shape of the data.
    • Measures of Central Tendency:
      • Mean: Average (use in normal distribution).
      • Median: Middle number (use in skewed distribution).
      • Mode: Occurs most often.
        • Unimodal
        • Bimodal: Has two modes, usually indicating good and bad scores.
      • Skews are created by outliers.
      • Negative Skew: Mean is to the left (negative side), mode is to the right.
      • Positive Skew: Mean is to the right.
    • Measure of Variation:
      • Range: Distance between the smallest and biggest number.
      • Standard Deviation: Average amount the scores are spread from the mean (bigger number = more spread).
  • Inferential Statistics: Establishes significance (meaningfulness).
    • Statistical Significance: Results are not due to chance; experimental manipulation caused the difference in means.
      • p < .05 = statistically significant; smaller is better.
    • Effect Size: Data has practical significance; bigger is better.

Ethical Guidelines (IRB Approval Needed for Studies Involving People)

  • Confidentiality: Names kept secret.
  • Informed Consent: Must agree to be part of the study.
  • Informed Assent: Minors and their parents must agree.
  • Debriefing: Must be told the true purpose of the study (done after for deception).
  • Deception: Must be warranted.
  • No Harm: Mental/physical.

Additional Vocabulary

  • Surveys: Usually turned into correlations; subject to self-report bias (errors when collecting survey data).
    • Social Desirability: People lie to look good.
    • Wording Effects: How you frame the question can impact your answers.
  • Random Sample (Selection): Method for choosing participants for the study; everyone has a chance to take part, increases generalizability.
  • Representative Sample: Sample mimics the general population (ethnic, gender, age).
  • Convenience Sample: Select participants based on availability – less representative and less generalizable.
  • Sampling Bias: Sample isn't representative due to convenience sampling.

Biological Basis

  • Refractory Period: Neuron must rest and reset before it can send another action potential (AP).

  • Neurotransmitters (NT): Chemicals released in the synaptic gap, received by neurons; classified as excitatory (increase APs) or inhibitory (decrease APs).

    • GABA: Major inhibitory NT.
    • Glutamate: Major excitatory NT.
    • Dopamine: Reward (short term) & fine movement – in hypothalamus, associated with addiction.
    • Serotonin: Moods (long-term), emotion, sleep in the amygdala; too little associated with depression.
    • Acetylcholine (ACh): Memory and movement -in hippocampus, associated w/ Alzheimer's
    • Norepinephrine: Sympathetic NS - too little assoc. w/ depression
    • Endorphins: Decrease pain.
    • Substance P: Pain regulation (abnormality increases pain and inflammation).

  • Hormones: If not in the nervous system, it's a hormone.

    • Oxytocin: Love, bonding, childbirth, lactation.
    • Adrenaline: Fight/flight.
    • Leptin: Makes you full (stops hunger).
    • Ghrelin: Makes you hungry.
    • Melatonin: Sleep.
    • Agonist: Drug that mimics a NT.
    • Antagonist: Drug that blocks a NT.
    • Reuptake: Unused NTs are taken back up into the sending neuron (antidepressants cause reuptake inhibition, blocking reuptake, a treatment for depression).

  • Psychoactive Drugs:

    • Depressants: Decrease NS activity (alcohol).
    • Stimulants: Increase NS activity (caffeine & cocaine).
    • Hallucinogens: Hallucinations and altered perceptions (Marijuana).
    • Opioids: Relieve pain (endorphin agonists) (heroin).
    • Tolerance: Needing more of a drug to achieve the same effects.
    • Addiction: Must have it to avoid withdrawal symptoms.
    • Withdrawal: Symptoms associated with sudden stoppage.

  • The Brain

    • Cerebellum: Movement, balance, coordination, procedural memory.
    • Brainstem / Medulla: Vital organs (HR, BP, breathing).
    • Reticular Activating System: Alertness, arousal, sleep, eye movement.
    • Cerebral Cortex: Outer portion of the brain – higher order thought processes · includes limbic system, lobes, corpus callosum
    • Limbic System
      • Amygdala: Emotions, fear
      • Hippocampus: Episodic and semantic memory
      • Hypothalamus: Reward/pleasure center, eating behaviors – link to endocrine system, homeostasis
      • Thalamus: Relay center for all but smell
      • Pituitary Gland: talks to the endocrine sys and hypothalamus – release hormones
      • Occipital Lobe: vision
      • Frontal Lobe: decision making, planning, judgment,
      • Prefrontal cortex: front of frontal lobe - executive function
      • Motor Cortex: back of frontal lobe - map of our motor receptors – controls skeletal movement
      • Parietal Lobe: sensations and touch - controls association areas incudes:
        • Somatosensory Cortex: map of our touch receptors
      • Temporal Lobe: hearing and face recognition, language
      • Association areas: receive input from multiple areas / lobes to integrate info
      • Left hemisphere only – damage to these results in aphasia (damaged speech)
        • Broca's Area: Inability to produce speech
        • Wernicke's Area: can't comprehend speech
        • Corpus Callosum: bundle of nerves that connects the 2 hemispheres – sometimes severed in patients with severe seizures - leads to "split-brain patients
        • Split-brain experiments: Image shown to R eye processed in L hemi – patient can say what they saw; image shown to L eye processed in R hemi, can't say what was seen
        • BRAIN PLASTICITY: Brain changes via damage and through experience
        • ENDOCRINE SYSTEM: sends hormones throughout the body
          • Pituitary Gland: Controlled by hypothalamus. release growth hormones
        • BRAIN RESEARCH:
          • EEG: shows broad brain activity - not specific - electrical output
          • fMRI: show brain activity in specific regions, measures oxygen

Heredity vs Environment

  • Evolutionary Psychology: Study how natural selection influences behavior.
  • Heredity (Nature): How genes influence your behavior.
  • Environment (Nurture): How outside situations influence your behavior (school).
  • Nature vs. Nurture: Answer is both.
    • Twin/Adoption Studies:
      • Genetics: Identical twins will have a higher percentage of also developing a disease.
      • Environment: Identical twins raised in different environments show differences.

Nervous System

  • Central NS: Brain and spinal cord.
  • Peripheral NS: Rest of the NS - relays to Central NS.
    • Somatic NS: Voluntary movement, has sensory and motor neurons.
    • Autonomic NS: Involuntary organs (heart, lungs, etc.) – contains the:
      • Sympathetic NS: Fight/flight (generally activates - exception digestion).
      • Parasympathetic NS: Rest/digest (generally inhibits - exception digestion).

Neuron and Neural Firing

  • Neuron: Basic cell of the NS.
    • Dendrites: Receive incoming NTs.
    • Axon: AP travels down this.
    • Myelin Sheath: Speeds up AP down the axon, protects axon.
    • Synapse: Gap between neurons.
    • Sensory Neurons: Receive sense signals from the environment and send signals to the brain.
    • Motor Neurons: Send signals to move – send signals from the brain.
    • Interneurons: Cells in the spinal cord/brain responsible for the reflex arc.
    • Reflex Arc: Important stimuli that skip the brain and route through the spinal cord for immediate reactions (hand on a hot flame).
    • Glia: Support cells - give nutrients and clean up around neurons.
    • Neurons Fire w/ an Action Potential: ions move across membrane sends an electrical charge down the axon
      • Resting potential: neuron maintains a -70mv charge when not doing anything
      • Depolarization: charge of neuron briefly switches from neg to pos. - triggers the AP
      • Threshold of depolarization: stimulus strength must reach this point to start the AP.
      • All or nothing principle: stimulus must trigger the AP past its threshold, but does not increase the intensity or speed of the
  • Cultural norms behvs of a particular group can influence research results
  • Experimenter bias/Participant bias: experimenter/participant expectations influences the outcome
  • Cognitive bias- bias in thinking/judgment
    • Confirmation bias - find info that supports our preexisting beliefs
    • Hindsight bias - "I knew it all along"
    • Overconfidence - overestimate our knowledge / abilities
    • Hawthorne effect - ppl change behavior when watched
  • Research needs peer review and adequate sample sizes
  • DISEASES & DISORDERS TO KNOW
    • Multiple sclerosis: destruction of myelin sheath, disrupts APs, causes impaired mobility, paralysis, pain
    • Myasthenia gravis: acetylcholine blocked, disrupts APs, causes poor motor control and paralysis
    • Blindsight: caused by lesions to primary visual cortex, ppl can "see" ie catch a ball etc despite being blind – evidence for association areas
    • Prosopagnosia: face blindness - damage to occipital and/or temporal lobe
    • Broca's aphasia - damage to Broca's area - stuttered speech
    • Wernicke's aphasia - damage to Wernicke's - jumbled speech
    • Phantom limb pain - pain from a limb that no longer is there (amputated) - caused by brain plasticity
    • Epilepsy - seizures - too much / little Glutamate / GABA
    • Alzheimer's-destruction of acetylcholine in hippocampus, memory loss
  • SLEEP
    • Consciousness - awareness of cognitive processes (asleep or awake?)
    • Circadian Rhythms: 24ish hour biological clock of Body temp & sleep
      • Disrupting it makes your internal clock get out of sync (jet lag and shift work do this)
    • Beta Waves: awake
    • Alpha Waves: high amp., drowsy
    • NREM (non REM) stages-
      • NREM 1: light sleep, has hypnagogic sensations (falling feeling)
      • NREM 2: bursts of sleep spindles