3 Sensation and Perception Flashcards
Sensation
the experience of sensory stimulation
Perception
the process of creating meaningful patterns from raw sensory information
Receptor cell
a special cell that responds to a particular type of energy
Absolute threshold
the least amount of energy that can be detected 50% of the time
Adaptation
an adjustment of the senses to the level of stimulation they are receiving
Difference threshold (just noticeable difference)
the smallest change in stimulation that can be detected 50% of the time
Weber’s law
the principle that the jnd for any given sense is a constant fraction or proportion of the stimulation being judged
Cornea
the transparent protective coating over the front part of the eye
Pupil
a small opening in the iris through which light enters the eye
Iris
the colored part of the eye
Lens
the transparent part of the eye inside the pupil that focuses light onto the retina
Retina
the lining of the eye containing receptor cells that are sensitive to light
Blind spot
the place on the retina where the axons of all the ganglion cells leave the eye and where there are no receptors
Fovea
the area of the retina that is the center of the visual field
Light
the small segment of the electromagnetic spectrum to which our eyes are sensitive
Rods
receptor cells in the responsible for night vision and perception of brightness
Cones
receptor cells in the retina responsible for color vision
Bipolar cells
Neurons that have only one axon and one dendrite; in the eye, these neurons connect the receptors on the retina to the ganglion cells
Visual acuity
the ability to distinguish fine details visually
Dark adaptation
increased sensitivity of rods and cones in darkness
Light adaptation
decreased sensitivity of rods and cones in bright light
Afterimage
sense experience that occurs after a visual stimulus has been removed
Ganglion cells
neurons that connect the bipolar cells in the eye to the brain
Optic nerve
the bundle of axons of ganglion cells that carries the messages from each eye to the brain
Optic chiasm
the point near the base of the brain where some fibers in the optic nerve from each eye cross to the other side of the brain
Feature detectors
specialized brain cells that only respond to particular elements in the visual field such as movement or lines of specific orientation
Hue
the aspect of color that corresponds to names such as red, green, and blue
Saturation
the vividness or richness of a hue
Brightness
the nearness of a color to white as opposed to black
Additive color mixing
the process of mixing lights of different wavelengths to create new hues
Subtractive color mixing
the process of mixing pigments, each of which absorbs some wavelengths of light and reflects others
Trichromatic theory
the theory of color vision that holds that all color perception derives from three different color receptors in the retina (usually red, green, and blue receptors)
Trichromats
people who have normal color vision
Color blindness
Partial or total inability to see hues
Dichromats
People who are blind to either red-green or yellow-blue
Monochromats
people who are totally color blind
Opponent-process theory
Theory of color vision that holds that three sets of color receptors (yellow-blue, red-green, and black-white) respond to determine the color you experience
Sound
A psychological experience created by the brain in response to changes in air pressure that are received by the auditory system
Sound waves
Changes in pressure caused when molecules of air or fluid collide with one another and then move apart again
Frequency
the number of cycles per second in a wave; in sound, the primary determinant of pitch
Hertz (Hz)
Cycles per second; unit of measurement for the frequency of sound waves
Pitch
Auditory experience corresponding primarily to frequency of sound vibrations, resulting in a higher or lower tone
Amplitude
the magnitude of a sound wave; in sound, the primary determinant of loudness
Decibel
unit of measurement fir the loudness of sounds
Overtones
Tones that result from sound waves that are multiples of the basic tone; primary determinant of timbre
Timbre
The quality or texture of sound; caused by overtones
Hammer, anvil, stirrup
the three small bones in the middle ear that relay vibrations of the eardrum to the inner ear
Oval window
Membrane across the opening between the middle ear and inner ear that conducts vibrations to the cochlea
Cochlea
part of the inner ear containing fluid that vibrates, which in turn causes the basilar membrane to vibrate
Basilar membrane
vibrating membrane in the cochlea of the inner ear; it contains sense receptors for sound
Organ of Corti
structure on the surface of the basilar membrane that contains the receptor cells for hearing
Place theory
Theory that pitch is determined by the location of greatest vibration on the basilar membrane
Frequency theory
theory that pitch is determined by the frequency with which hair cells in the cochlea fire
Volley principle
Refinement of frequency theory; it suggests that receptors in the ear fire in sequence, with one group responding, then a second, then a third, and so on, so that the complete pattern of firing corresponds to the frequency of the sound wave
Olfactory epithelium
Nasal membranes containing receptor cells sensitive to odors
Olfactory bulb
the smell center in the brain
Pheromones
chemical molecules that communicate information to other members of a species, and influence their behavior
Vomeronasal organ (VNO)
location of receptors for pheromones in the roof of the nasal cavity
Taste buds
structures on the tongue that contain the receptor cells for taste
Papillae
small bumps on the tongue that contain taste buds
Kinesthetic sense
senses of muscle movement, posture, and strain in muscles and joints
Stretch receptors
receptors that sense muscle stretch and contraction
Golgi tendon organs
receptors that sense movement of the tendons, which connect muscle to bone
Vestibular senses
the senses of equilibrium and body position in space
Vestibular sacs
sacs in the inner ear that sense gravitation and forward, backward, and vertical movement
Gate control theory
the theory that a “neurological gate” in the spinal cord controls the transmission of pain messages to the brain
Biopsychosocial theory
the theory that the interaction of biological, psychological, and cultural factors influence the intensity and duration of pain
Placebo effect
pain relief that occurs when a person believes a pill of procedure will reduce pain. The actual cause of the relief seems to come from endorphins
Figure
entity perceived to stand apart from the background
Ground
background against which a figure appears
Perceptual constancy
a tendency to perceive objects as stable and unchanging despite changes in sensory stimulation
Size constancy
the perception of an object as the same size regardless of the distance from which it is viewed
Shape constancy
tendency to see an object as the same shape no matter what angle it is viewed from
Color constancy
an inclination to perceive familiar objects as retaining their color despite changes in sensory information
Monocular cues
visual cues requiring the use of one eye
Binocular cues
visual cues requiring the use of both eyes
Aerial perspective
monocular cue to distance and depth based on the fact that more distant objects are likely to appear hazy and blurred
Texture gradient
monocular cue to distance and depth based on the fact that objects seen at greater distances appear smoother and less textured
Linear perspective
monocular cue to distance and depth based on the fact that two parallel lines seem to come together at the horizon
Motion parallax
Monocular distance cue in which objects closer than the point of visual focus seem to move in the direction opposite to the viewer’s moving head, and objects beyond the focus point appear to move in the same direction as the viewer’s head
Stereoscopic vision
combination of two retinal images to give a three-dimensional perceptual experience
Retinal disparity
binocular distance cue based on the difference between the images cast on the two retinas when both eyes are focused on the same object
Convergence
A visual depth cue that comes from muscles controlling eye movement as the eyes turn inward to view a nearby stimulus
Monaural cue
cue to sound location that requires only one ear
Binaural cue
cue to sound location that involves both ears working together
Autokinetic illusion
perception that stationary object is moving
Stroboscopic motion
apparent movement that results from flashing a series of still pictures in rapid succession, as in a motion picture
Phi phenomenon
apparent movement caused by flashing lights in sequence
Perceptual illusion
illusion due to misleading cues in stimuli that give rise to inaccurate or impossible perceptions
