Psychology

Nature vs. nurture

How genes and environment affect who we are.

Heredity (nature)

Traits passed down through genes from parents.

Environmental factors (nurture)

Things around us that affect how we develop.

Evolutionary perspective

How evolution affects behavior and thinking.

Natural selection

Helpful traits become more common over generations.

Eugenics

The harmful idea of improving humans by controlling reproduction.

Twin studies

Studies comparing twins to understand genes and environment.

Family studies

Studies of family members to understand inherited traits.

Adoption studies

Studies comparing adopted children with biological and adoptive families.

Neural cells

Cells that make up the nervous system.

Neurons

Cells that send and receive messages.

Glial cells

Cells that support and protect neurons.

Reflex arc

The nerve pathway that produces a quick, automatic response.

Sensory neurons

Carry information from the senses to the brain and spinal cord.

Motor neurons

Carry commands to muscles and glands.

Interneurons

Connect neurons within the brain and spinal cord.

Action potential

An electrical signal traveling down a neuron.

All-or-nothing principle

A neuron fires completely or does not fire.

Depolarization

When a neuron's inside becomes more positive.

Refractory period

A short time when a neuron resets after firing.

Resting potential

A neuron's normal electrical charge when not firing.

Reuptake

When a neuron takes back neurotransmitters it released.

Threshold

The minimum stimulation needed for a neuron to fire.

Nervous system

The body's communication system.

Central nervous system (CNS)

The brain and spinal cord.

Peripheral nervous system (PNS)

All nerves outside the brain and spinal cord.

Autonomic nervous system

Controls automatic body functions.

Parasympathetic nervous system

Calms the body and saves energy.

Sympathetic nervous system

Prepares the body for action or danger.

Somatic nervous system

Controls voluntary movements.

Neurotransmitters

Chemicals that carry messages between neurons.

Excitatory

Makes a neuron more likely to fire.

Inhibitory

Makes a neuron less likely to fire.

Dopamine

Involved in reward, motivation, and movement.

Serotonin

Helps regulate mood, sleep, and appetite.

Norepinephrine

Helps with alertness and the stress response.

Glutamate

The main excitatory neurotransmitter in the brain.

GABA

The main inhibitory neurotransmitter in the brain.

Endorphins

Natural chemicals that reduce pain.

Substance P

A chemical involved in sending pain signals.

Acetylcholine

Involved in muscle movement, learning, and memory.

Oxytocin

Involved in bonding and social connection.

Endocrine system

Glands that release hormones into the blood.

Hypothalamus

Brain region that helps control hormones and basic needs.

Pituitary gland

Gland that controls many other hormone glands.

Adrenaline

Hormone that prepares the body for action.

Leptin

Hormone that helps signal fullness.

Ghrelin

Hormone that signals hunger.

Melatonin

Hormone that helps control sleep timing.

Agonists

Substances that activate or increase a neurotransmitter's effects.

Antagonists

Substances that block a neurotransmitter's effects.

Reuptake inhibitors

Substances that prevent neurotransmitters from being taken back up too quickly.

Psychoactive drugs

Drugs that affect the brain and behavior.

Stimulants

Drugs that increase alertness and activity.

Caffeine

A stimulant found in coffee and tea.

Cocaine

A powerful, highly addictive stimulant.

Depressants

Drugs that slow down nervous system activity.

Alcohol

A drug that slows brain activity and affects judgment.

Hallucinogens

Drugs that change perception and sensory experiences.

Marijuana

A cannabis drug that can change mood and perception.

Opioids

Drugs that reduce pain but can cause dependence.

Heroin

An illegal, highly addictive opioid.

Tolerance

Needing more of a substance to get the same effect.

Addiction

Continued substance use despite harmful consequences.

Withdrawal

Symptoms that occur when reducing or stopping a substance the body depends on.

Brain stem

Controls basic functions like breathing and heartbeat.

Medulla

Controls breathing, heartbeat, and blood pressure.

Reticular activating system

Helps control alertness and wakefulness.

Cerebellum

Controls balance, coordination, and smooth movement.

Cerebral cortex

Outer brain layer responsible for complex thinking.

Left hemisphere

Usually specializes in language and logical processing.

Broca's area

Helps produce speech.

Broca's aphasia

Difficulty producing speech.

Wernicke's area

Helps understand language.

Wernicke's aphasia

Difficulty understanding language.

Right hemisphere

Often specializes in spatial and visual processing.

Limbic system

Brain network involved in emotion and memory.

Thalamus

Relays most sensory information to the cortex.

Hippocampus

Helps form new memories.

Amygdala

Helps process emotions, especially fear.

Corpus callosum

Connects the brain's two hemispheres.

Occipital lobes

Process vision.

Visual cortex

Brain area that processes visual information.

Feature detectors

Neurons that respond to specific visual features, like edges.

Temporal lobes

Help with hearing, language, and memory.

Parietal lobes

Process touch and spatial information.

Somatosensory cortex

Processes touch, pain, and body sensations.

Frontal lobes

Help with planning, decisions, and movement.

Executive functioning

Planning, organizing, and controlling behavior.

Higher-order thinking

Complex thinking, reasoning, and problem-solving.

Prefrontal cortex

Helps with judgment, planning, and self-control.

Motor cortex

Controls voluntary movements.

Split-brain research

Studies people whose corpus callosum has been cut.

Contralateral hemisphere organization

Each brain hemisphere mainly controls the opposite side of the body.

Plasticity

The brain's ability to change and adapt.

Brain Research and Procedures

EEG

Records the brain's electrical activity.

MRI

Uses magnets to create detailed brain images.

Case studies

Detailed studies of one person or a small group.

Phineas Gage

A famous case showing how brain damage can change personality.