Phantom Limb
Gate-Control Theory
Gestalt
An organized whole; Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes
Signal Detection Theory
Predicts when we will detect a weak stimulus; may be influenced by physiology, experience, and expectations
Selective Attention
Focusing conscious awareness on a particular stimulus
Absolute Threshold
The minimum stimulation required to detect a particular stimulus 50% of the time
Difference Threshold (Just Noticeable Difference)
The minimum difference between two stimuli required for detection 50% of the time
Kinesthetic Sense
Vestibular Sense
Inattentional Blindness
Failing to see visible objects when our attention is directed elsewhere
Bottom-Up Processing
Occurs when we are unfamiliar with environment; information processing that begins with the sensory receptors and works up to the brain’s integration of sensory information
Top-Down Processing
Occurs when we bring our expectations and prior knowledge to an environment; information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations
Sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
Perception
The process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful
Weber’s Law
Two stimuli must differ by a minimum percentage rather than a constant amount for the difference to be noticeable
Olfaction
Sound Location
Our brain detects differences in sound received by our two ears and uses this information to localize sound
Opponent-Process Theory
The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green; explains afterimages
Young-Helmholtz Trichromatic Theory
The theory that the retina contains three different types of color receptors — one most sensitive to red, one to green, one to blue — which, when stimulated in combination, can produce the perception of any color
Sensory Adaptation
Diminished sensitivity to a stimulus as a consequence of constant stimulation
Sensory Interaction
The principle that one sense may influence another, as when the smell of food influences its taste
Synesthesia
Monocular Depth Cues
Relative Height - objects higher in our fov are perceived as farther away
Relative Motion - as we move, stable objects might appear to move
Relative Size - similar objects appear smaller when farther away
Linear Perspective - parallel lines appear to converge to meet in the distance
Interposition - when one object partially blocks another, we perceive it as closer
Light and Shadow - shading produces sense of depth consistent with our assumptions of where light comes from
Binocular Depth Cues
Retinal Disparity - difference between retinal images from the two eyes
Convergence - inward rotation of our eyes as we focus on closer objects
Light Wave Characteristics
Frequency/Wavelength - Hue/Color
Amplitude - Intensity/Brightness
Sound Wave Characteristics
Frequency - Pitch
Amplitude - Volume
Figure-Ground
The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Accomodation
The process by which the eye’s lens changes shape to focus images of near or far objects on the retina
Sensorineural vs. Conductive Hearing Loss
Sensorineural - damage to hair cells or auditory nerve; can be treated with cochlear implants; happens with age as hair cells die
Conductive - damage to the middle ear (eardrum, ossicles); can be caused by Q-tips
Visual Cliff
A model of a cliff used to test depth perception in infants and young animals; shows that we are born to be wary of heights, and experience amplifies that fear
Cornea
The eye’s clear, protective outer layer, covering the pupil and iris; protects the eye and bends light to provide focus
Pupil
The adjustable opening in the center of the eye through which light enters
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina
Rods
Receptor cells that detect black, white, and gray, and are necessary for peripheral and night vision; share bipolar cells
Cones
Retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions; detect fine detail and give rise to color sensations; most have dedicated bipolar cells
Blind Spot
The point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there
Fovea
The central focal point in the retina, around which the eye’s cones cluster
Optic Nerve
The nerve that carries neural impulses from the eye to the brain
Eardrum
Tight membrane in the middle ear; vibrates from sound waves and transfers vibration to the ossicles
Ossicles
Hammer, anvil, stirrup; amplify and relay sound vibrations from the eardrum to the cochlea
Oval Window
The cochlea’s membrane covered opening; vibrates from the stirrup to jostle the fluid inside the cochlea
Cochlea
A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
Basilar Membrane
Ripples when the fluid inside the cochlea moves, triggering hair cells
Hair Cells
Receptor cells that line the basilar membrane in the cochlea; moves with sound waves and sends neural impulses to the auditory nerve
Auditory Nerve
Carries auditory neural messages to the thalamus and then on to the auditory cortex in the brain’s temporal lobe