Core Concepts in Psychology and Neuroscience
What is Psychology?
The scientific study of behavior and mental processes.
Psychological Perspectives
- Biological/Neuroscientific: Focuses on the brain, neurons, and genetics.
- Evolutionary: How behavior helps survival and reproduction.
- Behavior Genetics: How genes and the environment interact.
- Psychoanalytic/Psychodynamic: Unconscious processes and childhood experiences.
- Behavioral: Observable behavior and learning.
- Cognitive: Thinking, memory, and perception.
- Sociocultural: Social and cultural influences on behavior.
Research Methods
Hindsight Bias
The tendency to believe, after learning an outcome, that one would have foreseen it.
Scientific Method
A logical, systematic approach to solving a scientific problem.
Key Research Terms
- Hypothesis: A testable prediction.
- Operational Definition: A carefully worded statement of the exact procedures used in a research study.
- Case Study: An in-depth analysis of one subject or a small group.
- Observational Method: Learning new things by observing others. Advantages: Prosocial. Disadvantages: Antisocial.
- Wording Effects: Small changes in wording can change how people answer questions.
- Response Bias: A pattern of responses that does not accurately reflect the question.
- Random Sampling: Everyone has an equal chance of being studied.
Correlational and Experimental Methods
- Correlational Method: Measure of the direction and strength of the relationship between two variables.
- Positive Correlation: Variables change in the same direction.
- Negative Correlation: As one variable increases, the other decreases.
- Causation: Does correlation equal causation? No.
- Third Variables: Variables not accounted for can weaken the legitimacy of an experiment.
- Experimentation: The researcher changes one variable and measures the effect on another.
- Independent Variable (IV): The variable that is manipulated.
- Dependent Variable (DV): The variable that is measured.
- Experimental Group: Receives treatment.
- Control Group: Does not receive treatment.
- Confounding Variable: A factor other than the IV that may affect the results.
- Random Assignment: Assigning participants to groups by chance to reduce preexisting differences.
- Experimental Control: Ensuring no variables other than the IV affect the DV.
- Placebo Effect: Improvement due to belief in treatment, not the treatment itself.
- Placebo Control Group: Receives an inactive treatment.
Experimental Validity
- Expectancy Effect: Researcher expectations influence participant behavior.
- Single-blind: Participants do not know the study’s purpose.
- Double-blind: Neither participants nor researchers know who gets the treatment.
- Generalizability: Whether results apply to other situations.
- Replication: Repeating a study to confirm results.
- Informed Consent: Participants are given enough information to decide whether to participate.
The Nervous System
Neurons and Glial Cells
- Neurons: Nerve cells.
- Parts of a Neuron:
- Dendrites: Receive information.
- Cell Body: Holds the nucleus (DNA).
- Axon: Transmits messages.
- Glial Cells: Provide structure and support for neurons.
- Blood-Brain Barrier (BBB): Protects the brain from toxins and infections.
- Myelin Sheath: Wraps around the axon, insulates electrical charge, and speeds up signal transmission.
Neural Communication
- Action Potential: Electrical impulse that travels down the axon.
- Threshold: The minimum stimulation needed to trigger an action potential.
- All-or-None Response: Once the threshold is reached, the neuron fires fully.
- Synapse: The gap between neurons.
- Neurotransmitters: Chemical messengers that cross the synapse.
- Reuptake: When the sending neuron reabsorbs excess neurotransmitters.
- Inhibitory: Decreases firing.
- Excitatory: Increases firing.
Common Neurotransmitters
- Acetylcholine: Muscle action, learning, memory.
- Endorphins: Reduce pain, promote pleasure.
- Dopamine: Movement, reward, learning, memory.
- Serotonin: Mood, sleep, appetite.
- Glutamate: Excitatory; learning and memory.
- GABA: Inhibitory; calming, reduces stress.
- Epinephrine & Norepinephrine: Fight-or-flight, alertness.
- Agonists: Increase neurotransmitter action.
- Antagonists: Block neurotransmitter action.
System Organization
- Motor Neurons: Carry information from the brain to muscles and glands.
- Sensory Neurons: Carry information from receptors to the brain and spinal cord.
- Central Nervous System (CNS): Brain and spinal cord.
- Spinal Reflexes: Automatic responses without brain involvement.
- Peripheral Nervous System (PNS): Connects CNS to the rest of the body.
- Somatic Nervous System: Voluntary movement and sensory input.
- Sympathetic: Fight or flight (STRESS).
- Parasympathetic: Rest and digest (PEACE).
Endocrine System
- Endocrine System: The body’s slow chemical communication system.
- Hormones: Chemicals released into the bloodstream.
- Hypothalamus: Controls the pituitary gland; regulates hunger, thirst, temperature, and emotions.
- Pituitary Gland: Master gland; controls growth and other glands.
- Adrenal Glands: Regulate mood, energy, and stress response.
Brain Imaging and Anatomy
Brain-Imaging Methods
- PET: Biochemical activity using radioactive glucose (Function + Image).
- FMRI: Activity during tasks (Function + Image).
- EEG: Electrical activity (Function).
- CAT: X-ray, tissue (Images).
- MRI: Magnet measures activity (Images).
Brain Structures
- Brainstem: Connects the brain to the spinal cord; filters information.
- Medulla: Heartbeat and breathing.
- Pons: Sleep and arousal.
- Reticular Formation: Controls alertness and attention.
- Thalamus: Directs sensory information to the cortex (e.g., if a person loses hearing, it is often due to the thalamus; does not process smell).
- Cerebellum: Balance, coordination, movement, and memory.
- Amygdala: Emotions, fear, and aggression.
- Hypothalamus: Homeostasis, motivation, and emotion.
- Hippocampus: Forms new memories.
