AP Psychology Terms

Central Nervous System

The brain and spinal cord.

Peripheral Nervous System

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Autonomic Nervous System

The part of the peripheral nervous system that regulates involuntary bodily functions like heart rate, digestion, and breathing; includes the sympathetic and parasympathetic systems.

Somatic Nervous System

The division of the peripheral nervous system that controls the body’s skeletal muscles.

Neurons

A nerve cell; the basic building block of the nervous system.

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons; also involved in learning and thinking.

Spinal Cord

The central nervous system's conduit, transmitting nerve signals between the brain and the rest of the body.

Reflex Arc

A simple, automatic response to a sensory stimulus such as the knee-jerk response; only takes 1 or 2 brain cells to complete.

Depolarization

A stimulus causes the resting potential to move toward 0 mV; when reaching -55 mV, an action potential fires.

Refractory Period

A period of inactivity after a neuron has fired.

Resting Potential

The voltage difference between the inside and outside of a neuron when not firing.

Reuptake

The process by which a neuron reabsorbs a neurotransmitter after it has passed through a synapse.

Brain Stem

Begins where the spinal cord enters the skull; connects the brain to the spinal cord.

Medulla

Controls heart rate, blood flow, respiration, vomiting, and cranial nerves.

Reticular Activating System

A network of brainstem nuclei and neurons coordinating essential functions necessary for survival.

Cerebellum

Controls motor function and balance, processes input from the inner ear and eyes, and enables muscle memory.

Limbic System

A neural system including the hippocampus, amygdala, and hypothalamus; associated with emotions and drives.

Corpus Callosum

The band of fibers that connect the two brain hemispheres, facilitating communication between them.

Frontal Lobe

Responsible for planning, impulse control, and memory storage.

Parietal Lobe

Handles abstract/logical thinking and imagery.

Occipital Lobe

Processes visual information.

Temporal Lobe

Processes hearing, taste, and smell.

Somatosensory Region

Receives stimulation data from nerves.

Motor Cortex

Controls skeletal muscle movement.

Split Brain Research

Studies involving individuals with a severed corpus callosum to understand the distinct roles of brain hemispheres.

Broca Area

The brain's 'dictionary,' involved in speech production.

Wernicke Area

Involved in sentence structure and grammar comprehension.

Brain Plasticity

The brain’s ability to change and adapt, especially after damage or through experience.

EEG (Electroencephalograph)

Monitors electrical activity in the brain.

ESB (Electrical Stimulation of Brain)

Uses electrical currents via electrodes to stimulate brain areas and replace disrupted currents.

CT Scan (Computerized Tomography)

Uses x-rays to create detailed images of brain structures.

PET Scan (Positron Emission Tomography)

Shows brain function by tracking chemicals injected into the brain.

MRI (Magnetic Resonance Imaging)

Uses magnetic fields and radio waves to create images of brain structures.

fMRI (Functional Magnetic Resonance Imaging)

Measures brain activity by tracking blood and oxygen flow.

Lesioning

A surgical procedure that involves destroying malfunctioning brain tissue.

Sleep

A periodic, natural loss of consciousness distinct from coma, anesthesia, or hibernation.

Circadian Rhythm

The body’s internal clock that regulates 24-hour cycles of sleep, temperature, and other functions.

Jet Lag

A temporary sleep disorder caused by the disruption of the body’s circadian rhythm due to time zone changes.

NREM1

Light twilight sleep with relaxed muscles, slower breathing, theta waves, serotonin drop, and hypnic jerks.

NREM2

Deeper relaxation, continued theta waves, appearance of sleep spindles; night terrors possible.

NREM3

Deep sleep; delta waves begin, movement and digestion slow, sleepwalking and night terrors may occur.

REM Sleep

Dream phase with rapid eye movement, increased heart rate and breathing, and brain activity similar to being awake.

REM Rebound

The increase in REM sleep following sleep deprivation.

Insomnia

Recurring problems with falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks; the person may lapse directly into REM sleep at inappropriate times.

REM Sleep Behavior Disorder

A disorder where a person physically acts out vivid, often violent dreams with vocal sounds and sudden limb movements.

Sleep Apnea

A sleep disorder marked by temporary cessations of breathing during sleep and repeated brief awakenings.

Somnambulism (Sleepwalking)

Occurs during NREM 3; muscle paralysis by GABA and glycine may be incomplete, allowing the sleeper to act out emotions tied to dreams.

Absolute Threshold

The minimum stimulation needed to detect a stimulus 50% of the time.

Stimuli Detection (Signal Detection Theory)

A theory predicting how and when we detect a faint stimulus amid background noise; influenced by experience, expectations, motivation, and alertness.

Just Noticeable Difference (JND)

The smallest difference between two stimuli that can be detected 50% of the time.

Weber’s Law

To be perceived as different, two stimuli must differ by a constant percentage, not a fixed amount.

Synesthesia

A condition in which one sense is simultaneously perceived as another, such as tasting colors or seeing sounds.

Retina

The light-sensitive layer at the back of the eye that processes images and sends visual information to the brain.

Lens

Focuses light rays onto the retina.

Cones

Photoreceptors responsible for color and daylight vision.

Rods

Photoreceptors responsible for night vision and peripheral vision.

Afterimages

Visual images that remain after the original stimulus is removed, likely due to sensory adaptation.

Color Vision

The perception of reflected light rays; the color we see is the wavelength not absorbed by the object.

Prosopagnosia

A neurological disorder, also known as face blindness, making it difficult to recognize faces.

Blindsight

The ability of people who are cortically blind to respond to visual stimuli without conscious visual perception.

Pitch

The perceived highness or lowness of a sound, determined by its frequency.

Loudness

The subjective perception of sound intensity, influenced by the amplitude of sound waves.

Location (Sound Localization)

The brain's ability to determine where a sound is coming from using differences in arrival time and intensity between the ears.

Conduction Deafness

Hearing loss due to damage to the mechanical system that conducts sound to the cochlea.

Sensorineural Deafness

Hearing loss caused by damage to the inner ear (cochlea) or auditory nerve.

Vestibular Sense

The sense that monitors the head's position and balance, located in the inner ear.

Kinesthesis

The sense of the position and movement of individual body parts.

Pheromones

Chemicals secreted by animals that affect the behavior or development of others in the same species.

Gustation

The sense of taste; detects sweet, salty, sour, bitter, and umami (savory).

Taste Receptors

Specialized cells on the tongue that detect and transmit taste information to the brain.

Perception

The process of organizing and interpreting sensory information, enabling recognition of meaningful objects and events.

Bottom-Up Processing

Analysis that begins with sensory receptors and works up to the brain’s integration of sensory information; often driven by unexpected stimuli.

Top-Down Processing

Information processing guided by higher-level mental processes; based on expectations and prior knowledge.

Schemas

Mental models in long-term memory used to organize and interpret information based on past experiences.

Contexts

The environment can influence how we perceive stimuli.

Gestalt Principles

The whole is greater than the sum of its parts.

Phi Phenomenon

Perception of movement created by a series of still images shown in succession.

Figure and Ground

The visual system’s tendency to separate elements into a figure (the focus) and a background.

Proximity

Objects near each other are perceived as a group.

Similarity

Objects that are similar are grouped together.

Continuity

The tendency to perceive continuous patterns.

Simplicity

We interpret objects in the simplest way possible.

Closure

The tendency to fill in gaps in incomplete objects.

Perceptual Hypothesis

A guess made by the brain about what an object is, based on sensory cues and prior knowledge.

Depth Perception

The ability to judge the distance and three-dimensionality of objects using visual cues.

Linear Perspective

Parallel lines appear to converge at a point on the horizon.

Texture Gradients

Distant objects have less detail than closer ones.

Interposition

If one object overlaps another, it is perceived as closer.

Relative Size

Objects appearing smaller are perceived as farther away.

Height in Plane

Objects higher in the visual field are perceived as farther away.

Light and Shadow

Used by the brain to gauge depth and form.

Cocktail Party Effect

The ability to focus auditory attention on one stimulus while filtering out others.

Inattentional Blindness

Failure to notice visible objects when attention is directed elsewhere.

Binocular Cues

Depth cues (e.g., retinal disparity) requiring both eyes.

Monocular Cues

Depth cues available to either eye alone (includes interposition, linear perspective, texture gradients, relative size, height in plane, and light/shadow).

Visual Constancies

Perception of objects as unchanging in shape, size, and color despite changes in retinal image.

Perceived Movement

The illusion that distant objects move slower than closer ones, or illusions that simulate movement.

Prototypes

Mental representations of typical examples for a concept.

Assimilation of Schemas

Adding new information to existing mental frameworks.