SENSATION AND PERCEPTION VOCABULARY
TERM
Sensation
-
Perception
-
Bottom-up
processing
Top-down
processing
-
Selective Attention
Selective Inattention
Change blindness
Psychophysics
Absolute Threshold
Difference
Threshold (JND)
Signal Detection
Theory
DEFINITION
the process by which our sensory receptors and nervous system
receive and represent stimulus energies from our environment
the process of organizing and interpreting sensory information,
enabling us to recognize meaningful objects and events
analysis that begins with the sensory receptors and works up to the
brain’s integration of sensory information
-
information processing guided by higher-level mental processes, as
when we construct perceptions drawing on our experience and
expectations
- trying to attend to one thing by ignoring another
- cocktail party phenomenon: ability to carry on and follow a single
conversation in a room full of conversations, yet our attention can be drawn
to another conversation by key stimuli (your name)
- inattentional blindeness
- failing to see visible objects when our attention is directed elsewhere
- failing to notice changes in the enironment
- the study of relationships between the physical characteristics of
stimuli, such as their intensity, and our psychological experience of
them
-detection threshold
-minimum amount of stimulus needed to detect a change at least 50% of the
time it is presented
-level of stimulation right on our perceptual borderline
-discrimination threshold – ability to distinguish between two stimuli
-minimum distance between two stimuli that can be detected
-takes into consideration that there are four possible outcomes on each trial in
a detection experiment:
-Hit: signal present, participant reported sensing it
-Miss: signal present, participant did not sense it
-False alarm: signal absent, but participant reporting sensing it
EXAMPLE(S); NOTES
-Correct Rejection: signal absent and participant did not report sensing it
Weber’s Law
-JND is proportion of stimulus intensity
-the greater the magnitude of the stimulus, the large the differences must be to
be noticed; constant proportion
Subliminal Messages -stimuli below one’s absolute threshold for conscious awareness
- the activation, often unconsciously, of certain associations, thus
Priming
Sensory Adaptation
predisposing one’s perception, memory, or response
-unconscious change in response to environmental stimuli
-adaptation to differing stimuli leaves sensory system various adaptation
levels: this is the new reference standard of stimulation against which new
stimuli are judged
Habituation
-process by which we become accustomed to a stimulus, and notice it less and
less over time
Transduction
-input at the level of the receptor is converted into an electrochemical form of
communication used by the nervous system
-takes place at the level of the receptor cells and then the neural message is
passed to the nervous system
Parts of Eye
-cornea
-aqueous humor
-pupillary opening
-iris -pupil
-ciliary muscle -lens
-retina -fovea -cones / rods
-blind spot
-optic nerve
-at the point where the optic nerve exits the back of the eye there are
no rods and cones so no receptors for vision
-head and eye movements work avoid “blind spots” in our vision
-individual neurons in the primary visual cortex/occipital lobes that respond
to specific features of visual stimulus
- the processing of many aspects of a problem simultaneously; the
brain’s natural mode of information processing for many functions,
including vision
Blind Spot
Feature Detectors
Parallel Processing
-Ex: adapt to darkness; at first hard
to see but visual system adapts to
lack of light
-
studies of patients with
brain damage suggest that
the brain delegates the
work of processing color,
motion, form, and depth to
-
Afterimage Effect
-produced when staring at an “opponent color”
-if you stare at a green dot for 30 seconds and then look at a neutral
background you will likely experience a red after image
Opponent Process
Theory
-states that there are two kinds of cones, one that responds to red and green,
the other to blue and yellow, while the rods receive black and white input
-as one color in each pair is excited, the other is inhibited
-cells at thalamic level operate antagonistically in 3 color sets
Young Helmholtz
Trichromatic
Theory
-the cones in the retina of the eyes are activated by light waves associated
with blue, red, and green
Parts of the Ear
the sense or act of hearing
the number of complete wavelengths that pass a point in a given time
(for example, per second)
- a tone’s experienced highness or lowness depends on frequency
-external ear: (air conduction) pinna, external auditory canal
-inner ear: (fluid conduction) tympanic membrane (ear drum) malleus
(hammer), incus (anvil), stapes (stirrup), cochlea, oval window, round
window, auditory nerve, cochlear canal, organ of Corti hair cells, stereocilia,
basilar membrane, auditory nerve fibers
Place Theory
-suggests we identify pitch of sounds according to the location of vibrations
on the basilar membrane
Frequency Theory
-suggests we identify the pitch of sounds according to how rapidly the nerve
impulses fire
-at high frequencies, nerves fire one after another and in the auditory cortex
the number of impulses fired per second is translated into hertz, the unit of
Audition
Frequency
Pitch
different areas.
in contrast to serial
processing, step-by-step,
of most computers and of
conscious problem solving
-
-works like plucking a string on a
violin or guitar while pressing down
on the string at different spots on
the neck
measure for the frequency of a sound
Conduction vs.
Nerve Deafness
-conduction: refers to injury to the outer or middle ear structures; results from
the blockage of the transmission of sound waves; conductive hearing loss
-nerve: indicates impairment of structure(s) from the cochlea to the auditory
cortex; sensorineural hearing loss
Gate Control Theory
of Pain
-“gate” in the spinal cord that opens and closes to allow pain messages
through to the brain and to stop those messages
-substance “P” activity in the spinal cord opens the gate, release of
endorphins close gate
-tongue is coated with papillae which contain taste buds (taste cells),
-4 tastes: sweet, salty, bitter and sour
Taste
Kinesthetic System
Vestibular System
Lock & Key Theory
of Smell
-found in joints and ligaments
-transmits info. about location & position of limbs & body parts
- the sense of body movement and position, including sense of balance
ex: ear wax, damage to the ossicles
in the middle ear (conduction)
- cochlear implant: a device
for converting sounds into
electrical signals and
stimulating the auditory
nerve through electrodes
threaded into the cochlear
-
receptors located in the
semicircular canals and
the vestibular sacs which
connect the canals with the
cochlear, contain fluid that
moves when the head
moves, stimulating cilia,
hair-like receptors
-
odorants that are inhaled
through the nose, where
they contact the main
olfactory epithelium,
which contains various
olfactory receptors. These
-scent molecules reach olfactory epithelium in nasal cavity
-scent molecules contact receptor cells
-axons from receptors project directly to the olfactory bulbs of brain
Sensory interaction
-
Olfactory system
-
the principle that one sense may influence another, as when the smell
of food influences its taste
sense of smell;
a chemosensory system
-
Gustatory System
-
sense of taste;
a chemosensory system
-
-
Gestalt Rules of
Organization
olfactory receptors are
membrane proteins of
bipolar olfactory receptor
neurons in the olfactory
epithelium.
olfactory sensory neurons
converge in the olfactory
bulb in the limbic system
sending signals to such
areas as the amygdala
taste cells are contained in
bundles called taste buds,
which are contained in
raised areas known as
papillae that are found
across the tongue.
there are five different
types of taste receptors
known: salt, sweet, sour,
bitter, and umami
(savoriness)
-Law of Pragnanz: minimum tendency, see objects in their simplest form
-Proximity: objects near each other form groups
-Similarity: group like objects together
-Symmetry: perceive preferentially forms that make up mirror images
-Continuity: perceive preferentially fluid or continuous forms
-closure: “close up” objects that incomplete
Figure-ground
-
Depth perception
-
the organization of the visual field into objects (the figures) that
stand out from their surroundings (the ground)
the ability to see objects in three dimensions although the images
-
visual cliff: a laboratory
that strike the retina are two-dimensional, allows us to judge distance
Binocular Cues vs.
Monocular Cues
Phi phenomenon
Perceptual Set
Perceptual constancy
Constancies (Shape,
Size, and Brightness)
Perceptual
adaptation
Perceptual set
-Binocular Cues: require 2 eyes; convergence, retinal disparity
-Monocular Cues: require 1 eye; accommodation, brightness, elevation,
interposition, linear perspective, motion parallax, texture gradient
- an illusion of movement created when two or more adjacent lights
blink on and off in quick succession
-what we expect to see, hear, taste, touch, or smell influences what we
experience
-
perceiving objects as unchanging even as illumination and retinal
images change
Shape Constancy – an object appears to maintain its normal shape regardless
of the angle from which it is viewed
Size Constancy - an object appears to stay the same size despite changes in
the size of the image it casts on the retina as it moves further away or closer
Brightness – an object maintains a particular level of brightness regardless of
the amount of light reflected from it
- color constancy: perceiving familiar objects as having consistent
color, even if changing illumination alters the wavelengths reflected
by the objects
- in vision, the ability to adjust to an artificially displaced or even
inverted visual field
-
a mental predisposition to perceive one thing and not another
device for testing depth
perception in infants