AP Psych Units 3-4

Sensation: The process by which sensory receptors receive and transmit stimulus energies from the environment to the brain.

Perception: The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-up processing: Analysis that begins with sensory receptors and works up to the brain’s integration of sensory information.

Top-down processing: Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experiences and expectations.

Selective attention: The focusing of conscious awareness on a particular stimulus while ignoring others.

Inattentional blindness: Failing to see visible objects when our attention is directed elsewhere.

Change blindness: Failing to notice changes in the environment, especially when those changes occur gradually.

Transduction: The conversion of one form of energy into another, such as transforming stimulus energies (e.g., light, sound) into neural impulses the brain can interpret.

Psychophysics: The study of the relationship between physical characteristics of stimuli and our psychological experience of them.

Absolute threshold: The minimum stimulus intensity needed to detect a stimulus 50% of the time.

Signal detection theory: A theory predicting how and when we detect weak signals amid background noise, influenced by psychological factors like expectations and motivation.

Subliminal: Below one’s absolute threshold for conscious awareness, meaning the stimulus is detected without conscious perception.

Priming: The unconscious activation of certain associations, predisposing one’s perception, memory, or response.

Difference threshold: The minimum difference between two stimuli required for detection 50% of the time, also called the just noticeable difference (JND).

Weber’s law: The principle that, to be perceived as different, two stimuli must differ by a constant percentage rather than a constant amount.

Sensory adaptation: Diminished sensitivity to a constant or unchanging stimulus over time.

Perceptual set: A mental predisposition to perceive one thing and not another, influenced by experiences, expectations, and context.

Extrasensory perception (ESP): The controversial claim that perception can occur without sensory input, including telepathy, clairvoyance, and precognition.

Parapsychology: The study of paranormal phenomena, including ESP and psychokinesis.

Wavelength: The distance between successive peaks of a wave, determining properties like color in light or pitch in sound.

Hue: The dimension of color determined by the wavelength of light (e.g., blue, green, red).

Intensity: The amount of energy in a light or sound wave, perceived as brightness or loudness, determined by wave amplitude.

Pupil: The adjustable opening in the center of the eye that controls the amount of light entering.

Iris: The colored muscle around the pupil that controls the amount of light entering the eye by adjusting the size of the pupil.

Lens: A transparent, flexible structure behind the pupil that changes shape to focus images on the retina.

Retina: The light-sensitive inner surface of the eye that contains receptor cells (rods and cones) and processes visual information.

Accommodation: The process by which the eye’s lens changes shape to focus near or far objects on the retina.

Rods: Retinal receptors that detect black, white, and gray and are essential for peripheral and night vision.

Cones: Retinal receptors concentrated in the fovea that detect color and fine detail in well-lit conditions.

Optic nerve: The nerve that carries visual information from the retina to the brain.

Blind spot: The point where the optic nerve leaves the eye, creating a gap in vision due to the absence of receptor cells.

Fovea: The central focal point in the retina where cones are highly concentrated, allowing for sharp central vision.

Feature detectors: Specialized neurons in the visual cortex that respond to specific aspects of a stimulus, such as edges, angles, and movement.

Parallel processing: The brain’s ability to process multiple aspects of a visual scene (such as color, motion, shape, and depth) simultaneously.

Young-Helmholtz trichromatic (three-color) theory: The theory that the retina contains three types of color receptors (red, green, and blue) that combine to create the perception of any color.

Opponent-process theory: The theory that color perception is controlled by opposing retinal processes (red-green, blue-yellow, and black-white), explaining afterimages and color vision at the neural level.

Gestalt: A psychological approach that emphasizes our tendency to integrate pieces of information into meaningful wholes.

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

Grouping: The perceptual tendency to organize stimuli into coherent groups based on principles like proximity, similarity, continuity, and closure.

Retinal disparity: A binocular cue for depth perception that compares images from both eyes; the greater the disparity (difference), the closer the object appears.

Monocular cues: Depth cues that can be perceived using one eye, such as interposition, relative size, linear perspective, and texture gradient.

Phi phenomenon: An illusion of movement created when two or more adjacent lights blink on and off in rapid succession.

Perceptual constancy: The ability to recognize objects as unchanging (having consistent shape, size, and color) despite changes in lighting, distance, or angle.

Color constancy: The ability to perceive consistent color in objects even when lighting changes alter the wavelengths reflected by them.

Depth perception: The ability to perceive the world in three dimensions and judge distance, allowing us to determine how far away objects are.

Visual cliff: A laboratory device used to test depth perception in infants and young animals, typically involving a glass-covered drop-off.

Binocular cues: Depth perception cues that depend on the use of both eyes, such as retinal disparity and convergence.

Perceptual adaptation: The brain’s ability to adjust to changes in sensory input, such as adapting to a displaced or inverted visual field.

Audition: The sense or act of hearing.

Frequency: The number of complete wavelengths that pass a point in a given time, determining the pitch of a sound.

Pitch: A tone’s perceived highness or lowness, which depends on frequency.

Middle ear: The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that amplify sound vibrations.

Cochlea: A coiled, fluid-filled tube in the inner ear where sound waves are transformed into neural impulses by hair cells.

Inner ear: The innermost part of the ear containing the cochlea, semicircular canals, and vestibular sacs, which play roles in hearing and balance.

Sensorineural hearing loss: Hearing loss caused by damage to the cochlea’s hair cells or the auditory nerve, often due to aging or prolonged exposure to loud noise.

Conduction hearing loss: Hearing loss caused by damage to the mechanical structures of the ear (e.g., eardrum or middle ear bones) that conduct sound waves to the cochlea.

Cochlear implant: A device that converts sound into electrical signals and stimulates the auditory nerve, providing hearing for those with sensorineural hearing loss.

Place theory: A theory of pitch perception that suggests different frequencies stimulate different locations along the cochlea’s basilar membrane, explaining high-pitched sounds.

Frequency theory: A theory of pitch perception that suggests the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, explaining low-pitched sounds.

Gate-control theory: The theory that the spinal cord contains a neurological "gate" that either blocks pain signals or allows them to pass to the brain, influenced by psychological and physiological factors.

Kinesthesia: The system for sensing the position and movement of individual body parts, enabling coordination.

Vestibular sense: The sense of body movement and balance, regulated by the inner ear’s semicircular canals and vestibular sacs.

Sensory interaction: The principle that one sense may influence another, such as the way smell affects taste.

Embodied cognition: The idea that bodily sensations, gestures, and movements can influence cognitive processes, including thoughts and emotions.

Gustav Fechner: A psychologist and physicist who founded psychophysics and studied the relationship between stimulus intensity and perception, developing the concept of absolute thresholds.

Ernst Weber: A psychologist known for Weber’s Law, which states that the just noticeable difference (JND) between two stimuli is proportional to the magnitude of the original stimulus.

David Hubel: A neuroscientist who, along with Torsten Wiesel, discovered feature detectors—specialized neurons in the visual cortex that respond to specific elements of stimuli such as edges, angles, and movement.

Torsten Wiesel: A neuroscientist who worked with David Hubel to study how the brain processes visual information and demonstrated the role of feature detectors in vision. Learning: A relatively permanent change in behavior or knowledge due to experience.

Habituation: A decrease in response to a repeated stimulus over time.

Associative learning: Learning that certain events occur together; it can involve classical or operant conditioning.

Stimulus: Any event or situation that evokes a response.

Cognitive learning: The acquisition of mental information, whether by observing events, watching others, or through language.

Classical conditioning: A type of learning in which one learns to link two or more stimuli and anticipate events.

Behaviorism: The psychological perspective that focuses on observable behavior and dismisses mental processes as unscientific.

Neutral stimulus (NS): In classical conditioning, a stimulus that initially elicits no response before conditioning.

Unconditioned response (UR): An automatic, naturally occurring response to an unconditioned stimulus.

Unconditioned stimulus (US): A stimulus that naturally and automatically triggers a response.

Conditioned response (CR): A learned response to a previously neutral stimulus after conditioning.

Conditioned stimulus (CS): A previously neutral stimulus that, after association with an unconditioned stimulus, triggers a conditioned response.

Acquisition: The initial stage of learning in classical conditioning, when a neutral stimulus is first associated with an unconditioned stimulus.

Higher-order conditioning: A process in which a conditioned stimulus is paired with a new neutral stimulus, creating a second conditioned stimulus.

Extinction: The diminishing of a conditioned response when the conditioned stimulus is repeatedly presented without the unconditioned stimulus.

Spontaneous recovery: The reappearance of an extinguished conditioned response after a pause.

Generalization: The tendency to respond similarly to stimuli that are similar to the conditioned stimulus.

Discrimination: The learned ability to distinguish between a conditioned stimulus and other irrelevant stimuli.

Operant conditioning: A type of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment.

Law of effect: Thorndike’s principle that behaviors followed by favorable consequences become more likely, while behaviors followed by unfavorable consequences become less likely.

Operant chamber (also known as a Skinner box): A device used in operant conditioning research, containing a lever or key that an animal can manipulate to obtain reinforcement.

Reinforcement: In operant conditioning, any event that strengthens the behavior it follows.

Shaping: A process in operant conditioning in which reinforcers guide behavior toward closer and closer approximations of the desired behavior.

Discriminative stimulus: A stimulus that signals the presence of reinforcement, influencing a response.

Positive reinforcement: Increasing behaviors by presenting a positive stimulus after the behavior (e.g., giving a reward).

Negative reinforcement: Increasing behaviors by removing or reducing an aversive stimulus after the behavior (e.g., taking painkillers to relieve pain).

Primary reinforcer: An innately reinforcing stimulus that satisfies a biological need (e.g., food, water, warmth).

Conditioned reinforcer (also called a secondary reinforcer): A stimulus that gains its reinforcing power through association with a primary reinforcer (e.g., money, praise, tokens).

Reinforcement schedule: A pattern that defines how often a desired behavior will be reinforced.

Continuous reinforcement: Reinforcing the desired response every time it occurs, leading to rapid learning but also rapid extinction.

Partial (intermittent) reinforcement: Reinforcing a response only part of the time, leading to slower learning but greater resistance to extinction.

Fixed-ratio schedule: A reinforcement schedule that rewards a behavior after a set number of responses (e.g., earning a free coffee after every 10 purchases).

Variable-ratio schedule: A reinforcement schedule that rewards a behavior after an unpredictable number of responses (e.g., gambling, fishing).

Fixed-interval schedule: A reinforcement schedule that rewards a behavior after a fixed amount of time has passed (e.g., getting a paycheck every two weeks).

Variable-interval schedule: A reinforcement schedule that rewards a behavior at unpredictable time intervals (e.g., checking for a social media notification).

Punishment: Any consequence that decreases the likelihood of a behavior occurring again.

Biofeedback: A technique that allows individuals to control bodily functions (e.g., heart rate, muscle tension) through monitoring and feedback.

Respondent behavior: Behavior that occurs automatically in response to a stimulus (as in classical conditioning).

Operant behavior: Behavior that operates on the environment to produce consequences (as in operant conditioning).

Cognitive map: A mental representation of one’s environment, such as a rat’s map of a maze.

Latent learning: Learning that occurs but remains hidden until there is a reason to demonstrate it.

Insight: A sudden realization of a problem’s solution, rather than learning through trial and error.

Intrinsic motivation: The desire to perform a behavior for its own sake, due to internal satisfaction rather than external rewards.

Extrinsic motivation: The desire to perform a behavior to gain rewards or avoid punishment.

Coping: Efforts to reduce stress using emotional, cognitive, or behavioral methods.

Problem-focused coping: Addressing a stressful situation directly by changing the stressor or the way one interacts with it.

Emotion-focused coping: Managing stress by avoiding or ignoring the stressor and attending to emotional needs instead.

Learned helplessness: A condition in which repeated exposure to uncontrollable negative events leads to passive resignation and a perceived lack of control.

External locus of control: The belief that outside forces, such as luck or fate, determine one’s life outcomes.

Internal locus of control: The belief that one controls their own destiny through effort and decisions.

Self-control: The ability to regulate impulses and delay gratification to achieve long-term goals.

Observational learning: Learning by watching others and imitating their behavior.

Modeling: The process of observing and imitating a specific behavior.

Mirror neurons: Neurons in the brain that fire when performing an action or when observing another performing that action, enabling imitation and empathy.

Prosocial behavior: Positive, helpful, and constructive behavior that benefits others, often learned through observational learning.

Ivan Pavlov: A Russian physiologist known for discovering classical conditioning through his experiments with dogs and salivation.

John B. Watson: A psychologist who established behaviorism and conducted the "Little Albert" experiment, demonstrating classical conditioning in humans.

B. F. Skinner: A behaviorist who studied operant conditioning and developed the concept of reinforcement using the Skinner box.

Edward Thorndike: A psychologist known for the law of effect, which states that behaviors followed by positive outcomes are strengthened.

John Garcia: A psychologist who studied taste aversion, showing that some associations (like taste and nausea) are biologically predisposed to be learned quickly.

Robert Rescorla: A psychologist who demonstrated that classical conditioning involves cognitive processes, showing that predictability affects learning.

Edward Tolman: A psychologist who studied latent learning and developed the concept of cognitive maps in rats navigating mazes.

Albert Bandura: A psychologist best known for his Bobo doll experiment, which demonstrated observational learning, modeling, and the impact of aggressive role models.