Unit 1 Part 3 Psych

Bottom-up processing

"Processing that begins with sensory receptors and works up to the brain's integration of sensory information. Example: identifying a song by hearing each note."

Top-down processing

"Processing guided by experience, expectations, and prior knowledge. Example: reading messy handwriting using context."

Transduction

"Conversion of physical energy (like light or sound waves) into neural impulses the brain can interpret."

Absolute threshold

"Minimum stimulation needed to detect a stimulus 50% of the time."

Just Noticeable Difference (Difference Threshold)

"Smallest detectable difference between two stimuli 50% of the time."

Weber's Law

"To perceive a difference, two stimuli must differ by a constant proportion, not a constant amount."

Sensory adaptation

"Reduced sensitivity after constant exposure to an unchanging stimulus."

Sound waves

"Vibrations in air that our ears detect; amplitude = loudness, frequency = pitch."

Amplitude (sound)

"Height of a sound wave; determines loudness (measured in decibels)."

Frequency

"Number of sound wave cycles per second (Hz); determines pitch."

Pitch

"Perceived highness or lowness of a sound."

Place theory

"Different pitches trigger activity at different places along the cochlea's basilar membrane; explains high-pitched sounds."

Frequency theory

"Pitch is perceived by the rate of nerve impulses matching sound frequency; explains low-pitched sounds."

Volley principle

"Groups of neurons alternate firing to handle higher frequencies above 1000 Hz."

Sound localization

"Determining where a sound comes from using differences in loudness and timing between ears."

Conduction hearing loss

"Damage to eardrum or middle ear bones prevents sound from reaching cochlea."

Sensorineural hearing loss

"Damage to hair cells, cochlea, or auditory nerve; often from aging or loud noise."

Cochlear implant

"Electronic device that converts sounds into electrical signals to stimulate the auditory nerve."

Audition

"Sense of hearing; relies on sound wave vibrations."

Accommodation

"Process by which the lens changes shape to focus on near or distant objects."

Nearsightedness

"Condition in which nearby objects are seen clearly but distant ones are blurry (image focuses in front of retina)."

Farsightedness

"Condition in which distant objects are seen clearly but close ones are blurry (image focuses behind retina)."

Cornea

"Eye's clear protective outer layer that bends light for focus."

Pupil

"Adjustable opening in the center of the eye that lets light in."

Iris

"Colored muscle that controls pupil size and thus amount of light entering the eye."

Lens

"Transparent structure behind pupil that focuses light on the retina."

Retina

"Light-sensitive inner surface of the eye that contains receptor cells (rods and cones)."

Fovea

"Central focus area of retina with only cones; provides sharpest vision."

Cones

"Retinal receptors for color and fine detail; function in daylight."

Rods

"Retinal receptors for black, white, and gray; function in dim light."

Bipolar cells

"Neurons that receive input from rods and cones and transmit to ganglion cells."

Ganglion cells

"Neurons whose axons form the optic nerve."

Optic nerve

"Carries visual information from the eye to the brain."

Blind spot

"Area where optic nerve leaves the eye; no receptor cells located there."

Optic chiasm

"X-shaped area where visual information from each eye crosses to opposite side of brain."

Wavelength

"Distance between light wave peaks; determines perceived color (hue)."

Amplitude (light)

"Height of light wave; determines brightness or intensity."

Trichromatic theory

"Theory that retina has three types of color receptors—red, green, and blue; their combination produces all colors."

Opponent-process theory

"Color vision system that pairs colors (red-green, blue-yellow, black-white); explains afterimages."

Afterimage

"Visual experience of a complementary color after staring at a hue."

Color vision deficiency

"Partial or total inability to distinguish certain colors (e.g., red-green)."

Feature detectors

"Specialized brain cells that respond to specific features like shape, angle, or movement."

Prosopagnosia

"Face blindness; inability to recognize familiar faces."

Blindsight

"Ability to respond to visual stimuli without conscious awareness of seeing."

Gustation

"Sense of taste; includes sweet, sour, salty, bitter, umami, and oleogustus (fat)."

Olfaction

"Sense of smell; detects airborne chemical molecules."

Pheromones

"Chemical signals that influence behavior of other members of the same species."

Sensory interaction

"One sense influences another; e.g., smell affects taste."

Synesthesia

"Condition in which one sense triggers another; e.g., hearing colors or seeing sounds."

Gate control theory

"Theory that the spinal cord contains a 'gate' that can block or allow pain signals to reach the brain."

Phantom limb pain

"Sensation of pain in a missing or amputated limb."

Endorphins

"Brain's natural painkillers that reduce pain perception."

Kinesthesia

"Sense of body part movement and position."

Vestibular sense

"Sense of balance and body orientation; relies on semicircular canals and vestibular sacs in inner ear."

Selective attention

"Focusing conscious awareness on one stimulus among many (cocktail party effect)."

Inattentional blindness

"Failing to see visible objects when attention is directed elsewhere."

Change blindness

"Failing to notice changes in the environment due to selective attention."

Gestalt psychology

"Tendency to perceive whole patterns rather than parts; 'the whole is greater than the sum of its parts.'"

Figure and ground

"Organization of visual field into object (figure) and background (ground)."

Proximity

"Grouping nearby figures together."

Similarity

"Grouping together figures that look alike."

Closure

"Filling in gaps to create a complete, whole object."

Depth perception

"Ability to see objects in three dimensions and judge distance."

Binocular cues

"Depth cues that depend on the use of both eyes."

Convergence

"Inward turning of the eyes for close objects; brain uses muscle strain as a depth cue."

Retinal disparity

"Difference between images from each eye; greater disparity means closer object."

Monocular cues

"Depth cues available to each eye separately (e.g., linear perspective, relative size)."

Relative clarity

"Hazy objects appear farther away."

Relative size

"If two objects are similar, the smaller one appears farther away."

Texture gradient

"Gradual loss of detail indicates increasing distance."

Linear perspective

"Parallel lines appear to converge with distance."

Interposition

"When one object overlaps another, the overlapping object appears closer."

Motion perception

"Process of inferring speed and direction of moving objects."

Phi phenomenon

"Perception of movement when stationary lights blink in succession."

Stroboscopic movement

"Perceiving continuous motion from a rapid series of still images (animation)."

Perceptual constancy

"Perceiving objects as stable and unchanging despite changes in illumination or retinal image."

Color constancy

"Perceiving consistent color even under varying lighting."

Brightness constancy

"Perceiving objects as equally bright despite illumination differences."

Shape constancy

"Perceiving shape as constant even when viewing angle changes."

Size constancy

"Perceiving size as constant despite changes in distance."

Critical period

"Optimal early window when exposure to certain stimuli is necessary for normal development."