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