Transduction
A process by which sensory receptors produce neural impulses when they receive physical or chemical stimulation.
Sensory adaptation
Diminished sensitivity as a consequence of constant stimulation
Sensory Habituation
our perception of sensations is partially due to how focused we are on them
Cocktail Party Effect
The ability to focus one's listening attention on a single talker among a mixture of conversations and background noises
Sensation
Detection of physical energy by sense organs, which then send information to the brain, Bottom-up processing
Perception
A person's cognitive (mental) interpretation of events.
Cornea
Anatomy of the eye: outermost transparent layer protecting the eye; assists in light refraction
Pupil
Adjustable opening in the center of the eye through which light enters
Lens
A clear piece of curved glass or plastic that bends passing light to focus or spread the light rays
Retina
A multilayered sensory tissue that lines the back of the eye and contains the receptor cells to detect light.
Feature Detectors
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement
Optic Nerve
Comprised of the axons of retinal ganglion cells, this carries neural impulses from the eye to the brain.
Rods
Located in the periphery of the retina, these are sensory receptors for vision that work best in reduced illumination, and only allow perception of achromatic colors, low sensitivity to detail and are not involved in color vision.
Cones
Cone-shaped visual receptor cells; located in retina; works best in bright light; responsible for viewing color; greatest density in the fovea
Fovea
Point of central focus". Spot on the back of the retina that has more cones that anywhere else. Helps us see fine detail
Blind Spot
The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
Trichromatic Theory
Firing of red, green and blue cones cause color vision. (Young Helmholtz)
Color Blindness
a total inability to perceive colors
Afterimages
Images that occur when a visual sensation persists for a brief time even after the original stimulus is removed
Opponent-Process Theory
The theory that opposing retinal processes (red-green, yellow-blue, 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.
Cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
Pitch Theory
different portions of the membrane vibrate according to which pitch is sent through them
Place Theory
In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated
Frequency Theory
In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.
Conduction Deafness
An inability to hear resulting from damage to structures of the middle or inner ear.
Nerve Deafness
Inner-ear deafness resulting from damage to the cochlea, hair cells, or auditory nerve
Gate-Control Theory
The spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain.
Taste (Gustation)
chemical sense, involves four basic sensations: sweet, salty, sour, and bitter
Smell (Olfaction)
most primitive sense. information transmitted directly to limbic system not thalamus and cortex
Vestibular Sense
the sense of body movement and position, including the sense of balance
Kinesthetic Sense
The sense of body position and movement of body parts relative to each other
Absolute Threshold
Minimum stimulation needed to detect a particular stimulus 50% of the time
Subliminal Messages
brief auditory or visual messages that are presented below the absolute threshold
Difference Threshold
The minimum amount of difference that can be detected between two stimuli
Webers Law
principle that the just noticeable diffference of a stimulus is a constant proportion despite variations
Signal Detection Theory
A theory predicting how and when we detect the presence of a faint stimulus amid background noise
Top-Down Processing
Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.
Perceptual Set
A mental predisposition to perceive one thing and not another
Bottom-up Processing
Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
Gestalt Rules
we normally perceive images as groups, not as isolated elements; 4 factors that influence: proximity, similarity, continuity, closure
Proximity
Nearness
Similarity
A law of organization that says that objects that look similar tend to be grouped together when we perceive them.
Continuity
We perceive smooth, continuous patterns rather than discontinuous ones.
Closure
An ending or completion, or something that gives a sense of finality.
Constancy
The tendency to perceive certain objects in the same way regardless of changing angle, distance, or lighting
Size constancy
Perception of an object as the same size regardless of the distance from which it is viewed
Shape Constancy
the tendency to interpret the shape of an object as being constant, even when its shape changes on the retina
Brightness Constancy
the tendency to perceive the apparent brightness of an object as the same even when the light conditions change
Depth Cues
Binocular Cues
binocular Clues
depth cues, such as retinal disparity, that depend on the use of two eyes
Monocular Clues
depth cues, such as interposition and linear perspective, available to either eye alone