AP Psychology: Unit 1 Exam Study Guide Biological Bases of Behavior, Sensation, and Perception

Dendrites

Branch-like structures that receive the coming messages from other neurons.

Axon

Cable-like cell that sends electrical messages out of the Cell Body to other neurons and muscles. (THE BURGANS ARE COMING!!)

Soma (Cell Body)

Contains the Nucleus inside, neurons core that maintains cell health. Protects it, essentially.

Synapse

The gap between the Axon terminal where two neurons pass the messages to each other. Basically a game of telephone.

Action Potential

Brief electrical charge that travels down an Axon when the neuron fires.

Resting Potential

Waiting to be fired.

Neurotransmitters

Chemical messengers that travel across the Synapse to communicate neighboring cells.

Gamma-aminobutyric acid (GABA)

Primary neurotransmitter that calms down the nervous system activity.

Central Nervous System (CNS)

Brain and spinal cord, which are the commander for the body.

Peripheral Nervous System (PNS)

Sensory and motor nerves connecting the CNS to the rest of the body.

Somatic Nervous System

Unconsciously controls skeletal muscles.

Automatic Nervous System

Unconsciously controls internal functions like the heart and digestion.

Sympathetic Nervous System

Fight-or-Flight (lwk think of Conan Gray).

Parasympathetic Nervous System

Calms down the body, rest and digest.

Stimulants

Drugs that speed up neural activity and body functions (ex: caffeine, cocaine).

Depressants

Drugs that slow down bodily functions and neural activity (ex: alcohol, sedatives).

Tolerance

Needing larger doses of a drug over time to feel the same/stronger effect.

Withdrawal

Halting the habit of drug use and the uncomfortable physical and emotional baggage with it.

Addiction

The craving for a substance or feeling.

Frontal Lobe

Involved in speaking, muscle movements, planning, and judgment.

Parietal Lobes

Process touch, body position, and sensory input.

Temporal Lobes

Process auditory information and language comprehension.

Occipital Lobes

Process visual input coming from the eyes.

Motor Cortex

Controls voluntary muscle movements.

Somatosensory Cortex

Registers and processes body touch and movement sensations.

Broca’s Area

Controls physical speech production (frontal lobe).

Wernicke’s Area

Controls language comprehension and understanding (temporal lobe).

Cerebellum

Coordinates balance, voluntary movement, and procedural memory.

Hippocampus

Processes and consolidates conscious explicit memories.

Amygdala

Manages emotion, fear, and aggression.

Limbic System

A neural system associated with emotions and drives (includes amygdala, hippocampus, hypothalamus).

Reticular Formation

Controls arousal, alertness, and sleep-wake cycles.

Corpus Callosum

The thick band of neural fibers connecting the left and right brain hemispheres.

Brain Plasticity (Neuroplasticity)

The brain's ability to reorganize and adapt after damage or experience.

Brain Scanning Tools

Technologies used to image brain structure and function (EEG, CT, PET, MRI, fMRI).

NREM 1, 2, 3 & REM

The progressive stages of sleep, moving from light sleep to deep slow-wave sleep (NREM 3) and Rapid Eye Movement (REM) dreaming.

Delta Waves

Large, slow brain waves characteristic of deep NREM 3 sleep.

Sensation

The bottom-up process where sensory receptors detect physical energy from the environment.

Perception

The top-down mental process of organizing and interpreting sensory data.

Absolute Threshold

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

Difference Threshold (JND)

The minimum difference between two stimuli required for detection 50% of the time.

Weber’s Law

The principle that to be perceived as different, two stimuli must differ by a constant minimum percentage.

Single Detection Theory

Predicts how and when we detect the presence of a faint stimulus amid background noise, influenced by motivation and expectations.

Sensory Adaptation

Diminishing sensitivity to a constant, unchanging sensory stimulus.

Habituation

A decrease in behavioral response to a stimulus after repeated exposure.

Transduction

Converting physical energy from the environment into electrical neural impulses.

Cornea

The clear outer protective layer that bends light to help focus.

Lens

The transparent structure behind the pupil that changes shape to focus images on the retina.

Retina

The light-sensitive inner surface of the eye containing rods and cones.

Fovea

The central focal point in the retina where vision is sharpest.

Rods and Cones

Rods handle black/white/dim light vision; cones handle color and detail in bright light.

Optic Nerve

Carries neural impulses from the eye up to the brain's visual cortex.

Feature Detectors

Specialized neurons in the visual cortex that respond to specific edges, shapes, and angles.

Trichromatic Theory

The theory that the retina contains three types of color receptors sensitive to red, green, and blue.

Opponent-Process Theory

The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision and produce afterimages.

Visual Cortex

The area in the occipital lobe that processes visual input.

Tympanic Membrane (Eardrum)

A tight membrane that vibrates when hit by sound waves.

Hammer, Anvil, Stirrup

Three tiny bones in the middle ear that transmit eardrum vibrations to the cochlea.

Oval Window

The membrane opening of the cochlea that receives vibrations from the stirrup.

Cochlea & Basilar Membrane

The inner ear fluid-filled coil where sound waves trigger neural impulses via hair cells.

Auditory Nerve

Transmits neural messages from the inner ear to the brain.

Vestibular Sense

The sense of body movement and balance, including the sense of head position.

Kinesthetic Sense

The system for sensing the position and movement of individual body parts.

Olfaction

The chemical sense of smell processed by the olfactory bulb.

Bottom-Up Processing

Analysis that begins with sensory receptors and works up to the brain's integration of data.

Top-Down Processing

Information processing guided by higher-level mental processes, expectations, and past experiences.

Perceptual Constancy

Perceiving objects as unchanging even as illumination and retinal images change.

Figure-Ground

The organization of the visual field into objects (figures) that stand out from their surroundings (ground).

Gestalt Principals

Rules by which the brain organizes pieces of information into meaningful wholes (proximity, continuity, closure, similarity).

Depth Perception

The ability to see objects in three dimensions, allowing us to judge distances.

Monocular & Binocular Cues

Depth cues available to either eye alone (monocular) or requiring both eyes (binocular).

Linear Perspective, Relative Size, Interposition

Common monocular cues used to judge depth on a 2D plane.