Psychology Lesson 2: Variables, Neurons, and Neurotransmitters

A set of vocabulary-style flashcards covering key concepts from the notes: variables in experiments, sampling, the CNS and PNS, neuron structure, neurotransmitters, and related drugs/disorders.

Dependent variable

The variable that is measured in an experiment.

Independent variable

The variable that is deliberately manipulated by the experimenter.

Operational definitions

Definitions that qualify and quantify variables to allow objective understanding.

Control group

The group that receives no intervention or a neutral intervention; used for comparison.

Experimental group

One or more treatment groups that receive the intervention of the independent variable.

Control (in experiments)

The standard of comparison used to determine causality and isolate effects of the independent variable.

Confound

A variable that unintentionally affects the dependent variable and varies across conditions, introducing error.

Sampling

The process of selecting people from a population to participate in a study.

Sample

The subset of people chosen to participate in a study.

Convenience sample

A sample consisting of people conveniently available for the study (e.g., college students).

Random sample

A sample that gives members of the population an equal chance of being included.

Central Nervous System

The part of the nervous system that consists of the brain and spinal cord.

Peripheral Nervous System

The part of the nervous system that enables nerves to connect the CNS to the skin, muscles, organs, and glands.

Neuron

The basic unit of the nervous system; cells that receive, integrate, and transmit information.

Dendrites

Branch-like extensions that receive signals from other neurons.

Cell body

The part of the neuron where information from thousands of other neurons is collected and integrated.

Axon

The long, narrow outgrowth of a neuron that transmits information to other neurons.

Terminal buttons

Endings of the neuron that release neurotransmitters into the synapse.

Synapse

The site of communication between neurons where neurotransmitters cross the gap.

Neurotransmitters

Chemical substances that carry signals from one neuron to another.

Action potential

The neural impulse that travels along the axon and triggers neurotransmitter release.

Reuptake

The reabsorption of neurotransmitters into the presynaptic neuron.

Enzyme degradation

The breakdown of neurotransmitters in the synapse.

Agonists

Drugs that enhance the actions of neurotransmitters.

Antagonists

Drugs that inhibit the actions of neurotransmitters.

Random Assignment

An equal chance of being assigned to any level of the independent variable.

Acetylcholine

Neurotransmitter involved in motor control, attention, memory, learning, and sleep.

Norepinephrine

Neurotransmitter involved in arousal and alertness.

Serotonin

Neurotransmitter involved in emotional states, dreaming, and impulse control.

Dopamine

Neurotransmitter involved in reward, motivation, and motor control.

GABA (gamma-aminobutyric acid)

Inhibits neural firing; reduces anxiety; can be affected by alcohol.

Glutamate

The main excitatory neurotransmitter; involved in learning and memory.

Endorphins

Neurotransmitters that reduce pain and create sensations of reward.

Botox

Inhibits acetylcholine release at the neuromuscular junction, causing muscle relaxation.

Epinephrine (Adrenaline)

Triggers the fight-or-flight response and increases arousal.

Parkinson's disease

A neurodegenerative disorder linked to reduced dopamine activity, leading to motor symptoms.