Foundations of Biological and Experimental Psychology: Study Notes

Introduction to Psychological Research Methods

Key Characteristics of Good Research

• Good research is published, after review: Peer review ensures quality and credibility.

• Spread of misinformation and disinformation: Information (including myths) can be spread via media or unreviewed sources, so critical evaluation is essential.

• Goal of science: To be objective, not subjective.

• Objectivity: Findings are free from bias, well-measured, and consistent.

• Replication: Results should be reproducible in other studies.

• Replication crisis: Some well-known experiments have failed to replicate, raising concerns about reliability.

• Objectivity and validity: Key to good science.

• Objective measurements: Use consistent, agreed-upon instruments and observers (with a small margin of error).

• Measurement error: Always present; minimize by using standardized procedures.

• Generalizability: The extent to which results can be applied to other situations or populations.

• Sample size: Larger, more diverse samples increase generalizability.

• Reliability: Consistency of a measure across time or observers.

• Validity: The degree to which a test measures what it claims to measure.

How to Critically Evaluate Research

• Always consider whether the study uses objective, reliable, and valid measures.

• Check for sample size and representativeness.

• Consider whether the data can be generalized to other contexts or populations.

• Be aware of potential biases in data collection, analysis, or reporting.

• Single-case studies or studies without control groups are less reliable for drawing broad conclusions.

Types of Psychological Research

Descriptive Research

Descriptive research describes aspects of the data without manipulating variables.

• Case studies: In-depth study of a person or group, often used for rare or extraordinary cases.

• Naturalistic observation: Observing behavior in its natural context.

• Surveys and questionnaires: Collect data from large groups to describe trends or attitudes.

Correlational Research

Correlational research examines the relationship between two variables, indicating the strength and direction of the association.

• Correlation coefficient (r): Ranges from -1 to +1.

• Positive correlation: Both variables increase or decrease together.

• Negative correlation: One variable increases as the other decreases.

• No correlation: r = 0.

• Correlation does not imply causation.

Experimental Research

Experimental research manipulates one variable (independent variable) to observe its effect on another (dependent variable).

• Independent variable (IV): The variable manipulated by the researcher.

• Dependent variable (DV): The outcome measured.

• Control group: Does not receive the experimental treatment.

• Random assignment: Participants are randomly assigned to groups to reduce bias.

Biological Psychology: Neurons and the Nervous System

Neurons: Structure and Function

• Neurons: Basic units of the nervous system, specialized for communication.

• Parts of a neuron: Dendrites (receive signals), soma (cell body), axon (sends signals), axon terminals (transmit signals to other cells).

• Glia: Support cells that provide nutrients, remove waste, and insulate neurons.

Action Potentials and Synaptic Transmission

• Resting potential: The baseline electrical charge of a neuron, typically -70 mV.

• Action potential: A rapid change in electrical charge that travels down the axon when a neuron fires.

• Threshold: The minimum charge needed to trigger an action potential (usually around -55 mV).

• Refractory period: After firing, the neuron cannot fire again immediately.

• Synapse: The gap between neurons where neurotransmitters are released to communicate with other neurons.

Neurotransmitters

• Dopamine (DA): Involved in movement, motivation, and reward.

• Norepinephrine (NE): Involved in arousal and alertness.

• Serotonin (5-HT): Regulates mood, appetite, sleep, and pain perception.

• Glutamate (GLU): Main excitatory neurotransmitter, important for learning and memory.

• GABA: Main inhibitory neurotransmitter, reduces neural activity.

The Central Nervous System (CNS)

Brain and Spinal Cord

• Cerebral cortex: Surface of the brain, involved in higher-order functions.

• Gray matter: Contains neuron cell bodies.

• White matter: Contains myelinated axons, connects different brain regions.

• Spinal cord: Transmits information between the brain and the rest of the body.

Major Brain Divisions and Functions

• Frontal lobe: Planning, decision-making, movement, and personality.

• Parietal lobe: Sensory processing (touch, spatial awareness).

• Temporal lobe: Auditory processing, memory, and language.

• Occipital lobe: Visual processing.

Hemispheric Specialization

• Contralateral organization: Each hemisphere controls the opposite side of the body.

• Left hemisphere: Language, logic, analytical tasks.

• Right hemisphere: Spatial abilities, face recognition, creativity.

Brain Imaging and Damage

Brain Damage and Disorders

• TBI (Traumatic Brain Injury): Physical trauma to the brain.

• CTE (Chronic Traumatic Encephalopathy): Degenerative disease from repeated head injuries.

• Stroke: Disruption of blood flow to the brain, causing cell death and loss of function.

• Lesion studies: Examining the effects of brain damage to understand function.

Brain Imaging Techniques

• CT (Computed Tomography): Uses X-rays to create images of brain structure.

• MRI (Magnetic Resonance Imaging): Uses magnetic fields to produce detailed images of brain anatomy.

• fMRI (Functional MRI): Measures brain activity by detecting changes in blood oxygenation (BOLD signal).

• ERP (Event-Related Potentials): Measures electrical activity in response to specific stimuli.

Summary Table: Brain Imaging Methods

Method	What it Measures	Strengths	Limitations
CT	Brain structure (anatomy)	Quick, good for detecting bleeding or tumors	Lower resolution than MRI
MRI	Brain structure (anatomy)	High resolution, no radiation	Expensive, cannot be used with metal implants
fMRI	Brain activity (function)	Good spatial resolution, non-invasive	Poor temporal resolution, indirect measure of activity
ERP	Electrical activity (function)	Excellent temporal resolution	Poor spatial resolution

Key Equations and Concepts

• Resting membrane potential: $V_{rest} \approx -70\ \text{mV}$

• Action potential threshold: $V_{threshold} \approx -55\ \text{mV}$

• Correlation coefficient: $-1 \leq r \leq +1$

Conclusion

Understanding the basics of research methods and biological psychology is essential for interpreting scientific findings and appreciating the complexity of human behavior. Mastery of these foundational concepts prepares students for more advanced topics in psychology.