AP Psych Unit 1

Mean

The average of a set of numbers.

Median

The middle number when data are ordered from least to greatest.

Mode

The number that appears most often.

Correlational study

Investigates the relationship between two variables.

Experiment

A study where a researcher manipulates a variable to observe its effect on behavior.

Naturalistic observation

Observing and recording behavior in a natural setting without interfering.

Case study

An in-depth study of one individual or a small group.

Longitudinal study

Research that follows the same people over a period of time.

Cross-sectional study

Research that compares different groups of people at the same point in time.

Nervous system

The body's system for receiving, processing, and sending information.

Central nervous system (CNS)

The brain and spinal cord; the main decision-making system.

Peripheral nervous system (PNS)

All nerves outside the brain and spinal cord; connects the CNS to the body.

Spinal cord

Connects the brain to the peripheral nerves and carries signals to and from the brain.

Somatic nervous system

Controls voluntary movements and carries sensory information to the CNS.

Autonomic nervous system (ANS)

Controls involuntary body functions.

Sympathetic nervous system

Arouses the body and uses energy; fight-or-flight.

Parasympathetic nervous system

Calms the body and conserves energy; rest-and-digest.

Reticular Activating System (RAS)

Helps control alertness, attention, and wakefulness and filters sensory information.

Stage 1

Light sleep; transition from awake to asleep.

Stage 2

Deeper sleep; heart rate and body temperature decrease; sleep spindles and K-complexes occur.

Stage 3

Deep, slow-wave sleep; difficult to wake up.

REM sleep

Rapid eye movement sleep; vivid dreaming is common and memory consolidation occurs.

fMRI

Measures changes in blood flow to show which brain areas are active.

MRI

Uses magnets and radio waves to create detailed images of brain structures.

EEG

Uses electrodes on the scalp to measure electrical brain activity.

Informed consent

Participants understand the study and its risks before agreeing to participate.

Right to withdraw

Participants can leave the study at any time.

Confidentiality

Participants' personal information and data are kept private.

Debriefing

Researchers explain the study's purpose and procedures after participation, especially if deception was used.

Protection from harm

Researchers must minimize physical and psychological risks to participants.

Deception

Can sometimes be used when necessary, but participants must be protected and debriefed afterward.

Olfactory system

The body system responsible for the sense of smell.

Aphasia

An acquired language impairment usually caused by brain damage, often in the left hemisphere.

Broca's area

Brain area involved in producing speech; damage can cause difficulty speaking.

Wernicke's area

Brain area involved in understanding language; damage can cause difficulty understanding speech.

Standard deviation

A measure of how spread out scores are around the mean.

Thalamus

Relays most sensory information to the appropriate areas of the brain.

Amygdala

Involved in emotion, especially fear and threat.

Hippocampus

Helps form and consolidate new memories.

Brainstem

Controls basic survival functions such as breathing and heart rate.

Hypothalamus

Helps control hunger, thirst, body temperature, and hormone regulation.

Correlation

Two variables are related or move together.

Causation

One variable directly causes a change in another variable.

Frontal lobe

Reasoning, planning, decision-making, personality, and voluntary movement.

Parietal lobe

Processes touch and other body sensations; helps with spatial awareness.

Occipital lobe

Processes visual information.

Temporal lobe

Processes auditory information and helps with language and memory.

Cerebellum

Controls coordination, balance, and fine motor movement.

Neurotransmitter

A chemical messenger that carries signals between neurons.

Dopamine

Involved in reward, motivation, movement, and pleasure.

Serotonin

Involved in mood, sleep, appetite, and other body functions.

Hormone

A chemical messenger released into the bloodstream by glands.

Adrenaline (epinephrine)

Increases energy and prepares the body for action during stress.

Cortisol

A stress hormone that helps the body respond to stress.

Melatonin

Helps regulate the sleep-wake cycle.

Oxytocin

Involved in bonding, social connection, and childbirth.

Ghrelin

Increases hunger and appetite.

Leptin

Signals fullness and helps regulate appetite.

Rods

Eye cells that help in dim light and do not detect color well.

Cones

Eye cells that detect color and work best in bright light.

Cornea

Clear outer covering that helps focus light into the eye.

Pupil

Opening that lets light enter the eye.

Iris

Colored part of the eye that controls pupil size.

Lens

Structure in the eye that focuses light onto the retina.

Retina

Layer of cells in the eye that receives light and begins processing it.

Optic nerve

Carries visual information from the eye to the brain.

Opponent-process theory

Color vision model stating that visual signals are processed in opposing pairs: red-green, blue-yellow, and black-white.

Multi-Store Model

Framework proposing memory moves through sensory, short-term, and long-term stages.

Sensory memory

Holds information from the senses for a very short duration.

Short-term memory (STM)

Temporarily holds a small amount of information for immediate use.

Long-term memory (LTM)

Stores information for an extended duration, potentially permanently.

Rehearsal

Repeating information to maintain it in awareness or transfer it to permanent storage.

Retrieval

Bringing stored information back into conscious awareness.

Forgetting

Failure to retrieve or retain stored information.

Environmental stimulus

Sensory input detected from the surrounding environment.

Encoding

Processing information so it can be stored in memory systems.

Storage

Maintaining information in memory over time.

Working memory duration and capacity

Holds a limited amount of information for about 20 to 30 seconds without rehearsal.

Nature

The influence of genetic inheritance and biological factors on traits and behavior.

Nurture

The influence of environmental factors and personal experiences on traits and behavior.

Nature vs. Nurture debate

Discussion over whether human behavior is primarily driven by genetics or environmental factors.

Stimulants

Drugs that increase central nervous system activity and alertness.

Depressants

Drugs that slow down central nervous system activity.

Hallucinogens

Drugs that alter sensory perception, thoughts, and mood.

Circadian rhythm

The body's internal 24-hour biological clock regulating sleep, alertness, and temperature.

Cochlea

Spiral cavity of the inner ear that converts sound vibrations into neural signals.

Auditory transduction

Process of converting sound vibrations into neural impulses.

Transduction

Conversion of physical energy from the environment into neural signals.

Sensory adaptation

Diminished sensitivity to a constant stimulus over time.

Accommodation

Process by which the eye's lens changes shape to focus objects at varying distances.

Correlation

Statistical measure showing two variables are related without implying direct cause.

Causation

Relationship in which one event directly produces a change in another.

Tolerance

Decreased responsiveness to a substance, requiring larger doses to achieve the same effect.

Withdrawal

Physical and psychological symptoms experienced when stopping the use of an addictive substance.

Hormones

Chemical messengers secreted by glands into the bloodstream to regulate bodily functions.

Serial position effect

Tendency to recall the first and last items in a list better than items in the middle.

Primacy effect

Enhanced recall of information presented at the beginning of a sequence.