UNIT 3

diminished sensitivity as a consequence of constant stimulation

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage, rather than a constant amount

the minimum difference between two stimuli required for detection 50% of the time
- we experience this as a just noticeable difference (jnd)

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise)
- assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness

the minimum stimulation needed to detect a particular stimulus 50% of the time

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them

conversion of one form of energy into another
- in sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret

1. receive sensory stimulation, often using specialized receptor cells
2. transform that stimulation into neural impulses
3. deliver the neural information to our brain

failing to notice changes in the environment

failing to see visible objects when our attention is directed elsewhere

your ability to attend to only one voice among many, while also being able to detect your own name in an unattended voice

the focusing of conscious awareness on a particular stimulus

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
- starts at sensory receptors and works up to higher levels of processing

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

a given stimulus may trigger radically different perceptions, partly because of our differing perceptual set, but also because of the immediate context

concepts formed from experience that organize and allow us to interpret unfamiliar information

a mental predisposition to perceive one thing and not another
- top-down processing

knowledge, experience, and expectations that form schemas

names like David indicate a boy, blue indicates boy, pink indicates girl

the distance from the peak of one light/sound wave to the peak of the next
- shorter wavelength = higher frequency (blue)
- longer wavelength = lower frequency (red)

height of the light wave
- taller wavelength = brighter color
- shorter wavelength = duller color

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude

the dimension of color that is determined by the wavelength of light
- the color we experience (blue, green, etc.)

the opaque outer coating of the eye that is made of collagen fibers, which gives the eyeball its white color
- protects the eye and gives it structural integrity

protects the eye and bends light to provide focus
- light enters here

the adjustable opening in the center of they eye through which light enters
- constricts in light, dilates in dark

ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
- responds to light intensity and even to inner emotions
- every human has an iris that is unique to them

transparent structure behind the pupil that changes shape to help focus images on the retina
- as we get older, our lens becomes less flexible, and we are forced to adjust the distance of the object we are trying to see

light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

the process by which the eye's lens changes shape to focus near or far object son the retina

retinal receptors that detect black, white, and gray
- necessary for peripheral and twilight vision, when cones don't respond

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

the nerve that carries neural impulses from the eye to the brain

the point at which the optic nerve leaves the eye, creating a 'blind' spot because no receptor cells are located there

the central focal point in the retina, around which the eye's cones cluster

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement
- greatly helps with facial recognition

the processing of many aspects of a problem simultaneously
- brain's natural mode of information processing for many functions, including vision
- contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving

the theory that the retina contains three different 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

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision
- some cells are stimulated by green and inhibited by red, others are inhibited by green and stimulated by red

normal, myopic, hyperopic

correct eye shape, light rays focus on retina

nearsighted, long eye shape, light rays focus in front of retina

farsighted, short eye shape, light rays focus behind retina

process by which light gets translated into electrical signals and sent to the brain for neural processing

neurons that relay information from the retina to the brain via the optic nerve (made up on ganglion axons)

one of the main retinal interneurons and provide the main pathways from photoreceptors to ganglion cells

a chemical reaction that is triggered when light energy is absorbed by a substance's molecules
- leads molecules to experience a temporary excited state, which ends up activating the eye's bipolar and ganglion cells

specialized neurons found in the retina (rods and cones) that help to convert the light into electrical signals which stimulate physiological processes
- signals from the photoreceptors are sent through the optic nerve and up to the brain to be processed

an organized whole
- Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes

our mind is constantly working to make order out of chaos

perception is not just a capture of what we see, but we filter incoming information and construct perceptions. mind matters!

the organization of the visual field into objects (figures) that stand out from their surroundings (ground)

the perceptual tendency to organize stimuli into coherent groups

proximity, continuity, closure

group nearby figures together

perceive smooth, continuous patterns rather than discontinuous ones

fill in gaps to create a complete, whole object

the ability to see objects in three dimensions although the images that strike the retina are two dimensional
- allows us to judge distance

a laboratory device for testing depth perception in infants and young animals

a time during early postnatal life when the visual system (and other sensory functions) matures and develops within mammals
- usually first 5-6 years of life

a type of vision in which an animal has two functioning eyes capable of facing the same direction to perceive a single 3D image of its surroundings

difference in the direction of eyes

depth cues, such as retinal disparity, that depend on the use of two eyes

a binocular cue for perceiving depth
- by comparing images from the retinas in the two eyes, the brain computes distance - the greater the disparity (difference) between the two objects, the closer the object

depth cues, such as interposition and linear perspective, available to either eye alone
the way in which each of your eyes takes in visual information
- is used to judge distance, depth, and 3D space

higher objects are perceived as further away

if we know that two objects are the same size, we perceive the one that is furthest away as being smaller than the other

our tendency to experience difficulty naming a physical color when it is used to spell the name of a different color

in vision, the ability to adjust to an artificially displaced or even inverted visual field

perceive objects as having a constant size, even while our distance from them varies

perceive the form of familiar objects as constant even while our retinas receive changing images of them

we perceive an object as having a constant brightness even while its illumination varies
- depends on context

perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object

the ability to recognize objects without being deceived by retinal changes (color, brightness, shape, size, distance, or angle)

an illusion of movement created when two or more adjacent lights blink on and off in quick succession

continuous movement in a rapid series of slightly varying images

shading can produce the perception of depth or elevation

an object's motion/speed with respect to a particular point (any other object that is moving or stationary)

the sharper the angle of convergence (the more acute), the more distant it is

the object that blocks the other is perceived as closer

the sense or act of hearing

the amplitude of sound waves determines their loudness

the number of complete wavelengths that pass a point in a given time

a tone’s experienced highness or lowness, depends on frequency

low,low

measurement of sound, increase in tenfold

• threshold = 0 decibels

semicircular canals that have nothing to do with our hearing
- associated with balance and body position

pinna and auditory canal

a tight membrane, which vibrates from the waves channeled through the auditory canal from the visible outer ear

the narrow 'funnel-like' passageway that connects the outer ear to the middle ear and sends traveling sound waves down to the eardrum

visible part of the ear

the chamber between the eardrum and cochlea containing 3 tiny bones (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window (membrane)

hammer, anvil, stirrup - 3 tiny bones that increase the vibrations from the eardrum and transmit them to the cochlea through the oval window

a connective tissue membrane opening, located at the end of the middle ear and the beginning of the inner ear
- where the stirrup connects to the cochlea

a coiled, bony, fluid-filled tube in the inner ear
- sound waves traveling through the cochlear fluid trigger nerve impulses

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs