AP Psych Unit 2 (Biological Bases of Behavior)

Natural selection

The process in which organisms with traits that help them survive and reproduce are more likely to pass those traits to their offspring.

Ex: Giraffes with longer necks can reach more food, so they are more likely to survive and reproduce.

Running away from police = survive/no ticket

staying and hiding = found and ticketed.

Evolutionary psychology

Focuses on the evolution of behavior and cognition using principles of natural selection.

Ex: preschool →middle school →HS→college→ carrer (an environmental need made them either adapt or die off (extinction))

Behavior genetics

The study of how genes and the environment influence behavior and psychological traits.

Ex: Will lebron James kid’s be blessed with above-average athletic ability?

Why is Ada taller than Lucy?

Nature (genetics) V.S. Nurture (environment)

taller bc ate more food in the womb

Mutations

Random changes in DNA that can create new genetic traits.

Ex: A mutation might cause a bacterium to become resistant to an antibiotic.

Genes

Sections of DNA that contain instructions for traits.

Ex: A gene can influence characteristics such as eye color.

Genome

All of an organism's genetic material.

Ex: A person's genome contains all of their DNA.

Twin studies

Research comparing twins to understand the effects of genes and environment on traits.

Ex: Researchers compare identical and fraternal twins' IQ scores.

Identical twins

Twins who develop from one fertilized egg and have nearly identical DNA.

Ex: Two twins have very similar genetic makeup but may still develop different interests.

Fraternal twins

Twins who develop from two separate eggs fertilized by two different sperm cells; they share about 50% of their genes, like regular siblings.

Ex: Fraternal twins can look different and have different personalities.

Eugenics

The discredited idea that society should control reproduction to increase traits considered desirable.

Ex: Historical programs tried to prevent certain people from having children based on supposed genetic "fitness."

Interaction

The idea that genes and environment work together to influence behavior and traits.

Ex: A person may have genes that support athletic ability, but practice and coaching also affect how athletic they become.

Central nervous system (CNS)

The brain and spinal cord; it processes information and controls the body.

Ex: Your brain decides to move your hand, and the spinal cord helps send the message.

Peripheral nervous system (PNS)

All the nerves outside the brain and spinal cord that connect the CNS to the rest of the body.

Ex: Nerves carry information from your hand to your spinal cord.

Nerves

Bundles of neurons that carry messages throughout the body.\

Ex: Nerves carry a message from your foot to your brain when you step on something sharp.

Sensory neurons

Communicate sensory info. to the brain and spinal cord (CNS).

Ex: You touch something hot, and sensory neurons tell your brain about the heat.

(hearing, smelling, seeing, touching)

Sensory

Afferent = Arrives at the CNS

Motor neurons

Communicates movement from the brain and spinal cord (CNS) to parts of the body (motion).

Ex: Your brain sends a message to your arm muscles to move your hand.

Motor→Efferent = Exits the CNS

Interneurons

Neurons in the brain and spinal cord that connect sensory and motor neurons.

Ex: After sensing heat, interneurons help process the information and connect it to a response.

Somatic nervous system

Controls voluntary movements of your skeletal muscles.

Ex: You decide to run across a field.

Autonomic nervous system

Controls automatic/involuntary functions of your body.

Ex: Your heart continues beating without you thinking about it.

Parasympathetic nervous system

Calms the body and helps it rest and digest.

Ex: After a stressful test, your heart rate slows as you relax.

Sympathetic nervous system

Activates the body during stress or danger (fight-or-flight); prepares you for action.

Ex: You see a car suddenly coming toward you and your heart starts beating faster.

Reflexes

Automatic, rapid responses to a stimulus, often controlled through the spinal cord.

Ex: You quickly pull your hand away after touching a hot pan.

Acetylcholine (ACh)

Muscle movement, learning, and memory

Ex: Helps your muscles contract when you move.

Dopamine

Movement, motivation, reward, attention

Ex: Feeling motivated after doing well on something.

Endorphins

Reduce pain and can create feelings of pleasure

Ex: Your body releases them during exercise to help reduce pain.

GABA

Inhibitory; slows brain activity

Ex: Helps calm neural activity.

Glutamate

Excitatory; important for learning and memory

Ex: Helps your brain form and strengthen memories

Norepinephrine

Alertness, attention, and arousal

Ex: Makes you more alert when something unexpected happens.

Serotonin

Mood, sleep, and appetite

Ex: Helps regulate your sleep cycle.

Substance P

Helps transmit pain signals

Ex: Helps your brain receive information that something hurts.

Reuptake

When the sending neuron takes neurotransmitters back up after they cross the synapse.

Ex: The neuron "cleans up" neurotransmitters left in the synapse.

Agonist

A substance that mimics or increases a neurotransmitter's effects.

Ex: A drug can act like a neurotransmitter and activate its receptors.

Antagonist

A substance that blocks or decreases a neurotransmitter's effects.

Ex: A drug can block a neurotransmitter from activating its receptor.

Myasthenia Gravis (MG)

An autoimmune disorder that disrupts communication between nerves and muscles, causing muscle weakness.

Ex: Someone may have difficulty keeping their muscles working normally.

Multiple Sclerosis (MS)

A disease in which the immune system damages myelin, disrupting nerve signals.

Ex: Damaged myelin can make nerve messages travel less effectively.

Endocrine system

A system of glands that releases hormones into the bloodstream.

Ex: Hormones travel through your blood to affect different parts of your body.

Hormones

Chemical messengers released by endocrine glands that travel through the bloodstream.

Ex: Stress causes your body to release hormones that prepare you to respond.

Pituitary gland

A small gland that helps control many other endocrine glands and body processes.

Ex: It releases hormones involved in growth.

Oxytocin

A hormone involved in social bonding, childbirth, and breastfeeding.

Ex: Oxytocin is released during childbirth and helps with contractions.

Psychoactive drugs

Chemicals that change mood, perception, thinking, or behavior.

Ex: A drug changes how someone feels or experiences the world.

Substance use disorder

A pattern of substance use that causes significant problems or difficulty controlling use.

Ex: Someone continues using a substance even though it causes problems at school or home.

Depressants

Drugs that slow down brain and nervous system activity.

Ex: Alcohol can make someone feel relaxed and less alert.

Alcohol

A depressant that slows brain activity and impairs judgment and coordination.

Ex: Someone may have slower reactions after drinking.

Barbiturates

Depressants that slow brain activity and can cause relaxation and sleepiness.

Ex: Historically used as sedatives.

Opioids

Drugs that reduce pain and can produce relaxation; they can be highly addictive.

Ex: Used medically to treat severe pain.

Stimulants

Drugs that increase brain and nervous system activity.

Ex: A stimulant can increase alertness and energy.

Caffeine

A mild stimulant that increases alertness.

Ex: Coffee can help someone feel more awake.

Nicotine

An addictive stimulant found in tobacco products.

Ex: Nicotine can temporarily increase alertness.

Cocaine

A powerful stimulant that increases dopamine activity and alertness.

Ex: Can cause increased energy and heart rate.

Methamphetamines

Powerful stimulants that strongly increase brain activity.

Ex: Can cause intense alertness and energy.

Ecstasy (MDMA)

A psychoactive drug that can produce increased energy, emotional closeness, and altered perception.

Ex: Someone may feel unusually energetic and socially connected.

Hallucinogens

Drugs that distort perception and can cause sensory experiences that aren't actually occurring.

Ex: LSD can cause someone to see or hear things differently.

Near-death experience

An unusual experience sometimes reported during a life-threatening event, often involving bright lights or a sense of leaving the body.

Ex: Someone who survives a serious medical emergency reports seeing a bright light.

LSD

A powerful hallucinogen that alters perception, mood, and thinking.

Ex: Colors or shapes may appear very different from normal.

Marijuana (cannabis)

A psychoactive drug that can alter perception, mood, memory, and coordination.

Ex: Someone may experience altered time perception.

Addiction

Compulsive substance use despite harmful consequences.

Ex: Someone keeps using a substance even after it causes problems.

Tolerance

Needing more of a substance to get the same effect.

Ex: A person needs more of a substance than before to feel the same effect.

Withdrawal

Physical or psychological symptoms after stopping or reducing a substance.

Ex: Someone may experience anxiety or irritability after stopping a substance.

Ghrelin

A hormone that increases hunger.

Ex: Ghrelin levels rise when you're hungry.

Melatonin

A hormone that helps regulate the sleep-wake cycle.

Ex: Melatonin increases in the evening and helps prepare your body for sleep.

Mirror Neurons

Firing when viewing or imitating an action

Monkey see, Monkey do

Psychoactive drugs

Drugs that change how your brain feels or works.

Ex: A drug makes you feel sleepy or more energetic.

Substance use disorder

When someone can't control their use of a drug even when it causes problems.

Ex: Someone keeps using a drug even though it's hurting their life.

Depressants

Drugs that slow down the brain.

Ex: Alcohol can make you feel sleepy and relaxed.

Alcohol

A drug that slows down the brain and can affect judgment.

Ex: Someone may have trouble walking after drinking.

Barbiturates

Drugs that slow brain activity and can make you sleepy.

Ex: They have been used to help people sleep.

Opioids

Drugs that reduce pain and slow the body down.

Ex: Some are used by doctors for serious pain.

Stimulants

Drugs that speed up the brain and body.

Ex: They can make you feel more awake.

Caffeine

A stimulant that helps you feel more awake.

Nicotine

An addictive drug found in tobacco that stimulates the brain.

Ex: can make more alert

Cocaine

A strong stimulant that makes the brain more active.

Ex: It can make someone feel very energetic.

Methamphetamines

Very strong stimulants that speed up the brain a lot.

Ecstasy (MDMA)

A drug that can make people feel energetic and emotionally close to others.

Hallucinogens

Drugs that can make you see or feel things differently from reality.

Near-death experience

A strange experience some people report after being very close to dying.

Ex: Someone may report seeing a bright light.

LSD

A hallucinogen that strongly changes what you see and feel.

Marijuana

A drug that can change mood, memory, and perception.

Addiction

When someone really needs a drug and has trouble stopping.

Tolerance

When your body gets used to a drug, so you need more to get the same effect.

Withdrawal

Uncomfortable effects that can happen when someone stops using a drug they are dependent on.

Ghrelin

A hormone that tells your brain "I'm hungry!"

Melatonin

A hormone that helps tell your body "it's time to sleep."

Hindbrain

Controls basic survival functions and movement

Ex: Breathing, heartbeat, balance

Midbrain

Helps with movement, attention, and responding to sights/sounds

Ex: Turning toward a loud noise

Forebrain

Controls higher thinking, emotions, senses, and decision-making

Ex: making a decision

Brainstem

Connects the brain to the spinal cord and controls basic life functions

Ex: Breathing and heartbeat

Medulla

Controls automatic functions like breathing and heart rate

Ex: Heart keeps beating while you sleep.

Thalamus

Acts like a relay station, sending sensory information to the correct brain areas

Ex: Sends information about a sound to the auditory cortex

Reticular formation

Controls alertness and arousal

Cerebellum

Controls balance, coordination

Limbic system

Involved in emotion, motivation, memory, and basic drives

Ex: feeling fear or hunger

Amygdala

Emotions

Ex: fear

Hypothalamus

Controls hunger, thirst, body temperature, and hormones

Hippocampus

Helps create and store explicit memories (explain/new)

Cerebral cortex

Outer layer of the brain; thinking and senses

Frontal lobes

Planning, decisions, personality

Impulse control, in charge of making emotional decisions.

Motor cortex

Controls voluntary movement

Parietal lobes

Processes touch

Somatosensory cortex

Receives body sensations

Occipital lobes

Processes vision