Psych Ch. 4

color blindness

a genetic disorder that prevents an individual from distinguishing between certain colors deficiency in their cones most common - deficiencies in red-green system very rare to see no color at all

skin senses

skin is our largest organ protects internal organs, holds body fluids, produces sensations of touch, warmth, and cold, and provides essential info about pain

pupil

small opening in the middle of the iris changes sizes to let in different amounts of light

chemical senses

smell and taste - respond to chemical molecules rather than forms of energy such as light and sound waves smell and taste receptors are located near one another and often interact - can't separate the sensations

auditory canal

sound waves travel down and bounce into the ear drum

ganglion cells

specialized neurons that connect the bipolar cells bundled axons form the optic nerve

bipolar cells

specialized neurons that connect the rods and cones with the ganglion cells

feature detectors

specialized neurons that respond only to certain sensory info

cochlea

spiral-shaped, fluid filled structure that contains the basilar membrane and hair cells

signal detection theory

states that sensation depends on the characteristics of the stimulus, the background stimulation, and the detector selective attention enables you to filter out and focus on only selected sensory messages

oval window

stirrup transmits the amplified vibrations to the oval window smaller membrane separating the middle ear from the inner ear relays vibrations to the cochlea

depth perception

the ability to perceive 3-D space and to accurately judge distance

frequency theory

the basilar membrane vibrates at the same frequency as the sound wave explains how low-frequency sounds are transmitted to the brain

gate-control theory of pain

the brain regulates pain by sending signals down the spinal cord that either open or close sensory pathways if the brain signals the gates to open, pain is experienced if the brain signals the gates to close, pain is reduced anxiety and fear can intensify pain laughter can minimize pain

accommodation

the change in the curvature of the lens that enables the eye to focus on objects at various distances

convergence

the closer the object, the more the eyes converge, or turn inward

selective attention

the cognitive process of selectivity concentrating on one or more aspects of the environment while filtering out or ignoring other info

cochlea

the coiled, snail-shaped structure in the inner ear containing receptors for hearing

sensory adaptation

the decline in sensitivity to a constant stimulus

pinna

the flap of skin and cartilage attached to each side of our head catches sound waves and channels them into the auditory canal

figure-ground theory

the human tendency to distinguish between figure and ground is the most fundamental Gestalt principle or organization figure - main element of a scene that clearly stands out ground - less distinct background of the scene

pain

the unpleasant sensation of physical discomfort or suffering plays a key survival role by warning about potential or actual injuries

afterimage

the visual experience that occurs after the original source of stimulation is no longer present

law of closure

there is a tendency to fill in the gaps in an incomplete image

law of proximity

there is a tendency to perceive objects that are physically close to one another as a single unit

law of similarity

there is tendency to perceive objects of a similar size, shape, or color as a unit

taste

tongue is covered with bumps called papillae papillae are in turn covered with taste buds tastte buds are also found in the palate and the back of the throat 4 major taste sensations - sweet, sour, salty, and bitter umami - associated with the taste of protein found in meats and meat broths

Gustav Fechner

experimental psychologist demonstrated that mental processes can be measured

gate-control theory

explains how the nervous system blocks or allows pain signals to pass to the brain

Gestalt principles of organization

founded by Max Wertheimer we actively process our sensations according to consistent perceptual rules rules create full perceptions or gestalts that are meaningful, symmetrical, and as simple as conditions will allow

opponent-process theory

ganglion cells process color in opposing pairs of red or green, black or white, and blue or yellow

auditory system

hearing plays a vital role in language development and social interactions transducer sound waves into neural messages that the brain the processes into what we consciously hear

relative size

if 2 or more objects are assumed to be similar size, the object that appears larger is perceived as being closer

cornea

light waves from the outside first enter the eye here a clear membrane covering the visible part of the eye protects eye and helps gather and direct incoming light waves

retina

light-sensitive membrane at the back of the eye contains millions of sensory receptors for vision transduction of light waves happens here

David Hubel

neurophysiologist researched feature detectors and helped demonstrate the presence of specialized neurons in the occipital lobe's visual cortex that have the ability to respond to specific features of an image

Torsten Wiesel

neurophysiologist who collaborated with Hubel expanded scientific knowledge of sensory processing and perception

linear perspective

parallel lines appear to converge toward a vanishing point as they recede into the distance

body senses

provide essential info about your position and orientation in space

vestibular sense

provides sense of balance and equilibrium the inner ear contains receptors that are especially important for maintaining balance the semicircular canals are filled with fluid and lined with hairlike receptor cells that shift in response to motion they provide the brain with important info about the body's posture and head position

touch

receptors are not evenly distributed among the different areas of our body helps us communicate feelings of support, conformity, and love

binocular depth cues

require the use of both eyes to process distance or depth cues

monocular depth cues

require use of only one eye to process distance or depth cues

basilar membrane

runs the length of the cochlea holds the hair cell receptors for hearing

selection

selecting where to direct our attention is the first step in perception selective attention and feature detectors help explain why we pay attention to some stimuli in our environment and not to others

hair cells

sensory receptors embedded in the basilar membrane transducer the physical vibration of the sound waves into neural impulses

hammer, anvil, stirrup

3 tiny bones in middle ear joint action doubles the amplification of sound

trichromatic

3-color theory 3 primary colors - red, green, blue Hermann von Helmholtz color receptors that correspond with 3 primary colors

visual cliff experiment

Eleanor Gibson placed infants on a Plexiglas-topped table on one side, there was a sheet of high-contrast red-and-white-checkered cloth flush against the underside of the glass on other end she placed the fabric 4 feet under the table to create a visual cliff infants usual refused to go beyond the visual cliff depth perception is innate

middle ear

amplifies waves

motion parallax

as you move, you use the peed of passing objects to estimate the distance of the objects

color vision

can identify about 7 million different color combinations

auditory nerve

carries the neural messages to the thalamus and then to the temporal lobe's auditory cortex

nerve deafness

caused by damage to the cochlea, hair cells, or auditory nerve exposure to noises such as headphones playing at full blast can damage hair cells and cause permanent hearing loss hearing aids cannot help

conduction deafness

caused when the tiny bones in the middle ear are damaged and cannot transmit sound waves to the inner ear hearing aids can amplify sound and help overcome it

outer ear

collects sound waves

visual system

most complex and most important sense transducer light waves into neural messages that the brain then processes into what we consciously see

receptors

detect and then convert light waves, sound waves, chemical molecules, and pressure into neural impulses that are transmitted to the brain

place theory

different frequencies excite different hair cells at different locations along the basilar membrane high-frequency sounds cause maximum vibrations near the stirrup end of the basilar membrane lower-frequency sounds cause maximum vibrations at the opposite end

Ernest Heinrich Weber

discovered just noticeable difference (JND) and Weber's Law

aerial perspective

distant objects often appear hazy and blurred compared to close objects

tympanic membrane

eardrum tightly stretched membrane located at the end of the auditory canal vibrates when hit by sound waves vibrations of the eardrum match the intensity and frequency of the incoming sound waves

rods

the long, thin visual receptor cells in the retina that are highly sensitive to light, but not to color responsible for peripheral vision and black-and-white vision

difference threshold

the minimal difference needed to notice a stimulus change aka just noticeable difference

absolute threshold

the minimum intensity at which a stimulus can be detected at least 50% of the time

smell

the mucous membrane at the top of each nostril contains receptor cells that absorb airborne chemical molecules olfactory receptors can detect over 10,000 different smells communicate neural messages to the olfactory bulb

visual cortex

the optic nerve carries visual info to the brain's visual cortex lies in the occipital lobe at the back of the brain

blind spot

the point at the back of the retina where the optic nerve leaves the eye

sensation

the process by which our sensory receptors respond to light, sound, odor, textures, and taste and transmit that info to the brain eyes, ears, nose, tongue, and skin create a sensory system that receives and processes info from the environment

transduction

the process by which sensory receptors convert the incoming physical energy of stimuli, such as light waves, into neural impulses that the brain can understand

perception

the process by which the brian actively selects, organizes, and assigns meaning to incoming neural messages sent from sensory receptors

pitch

the relative highness or lowness of a sound

retinal disparity

the separation of the eyes causes different images to fall on each retina when 2 retinal images are very different, we interpret the object as being close by when two retinal images are more nearly identical, the object is perceived as being farther away a person with only one eye lacks retinal disparity and would have difficulty climbing an irregular set of stairs

cones

the short, thick visual receptor cells, concentrated near the center of the retina, responsible for color vision and fine detail

Weber's Law

the size of the JND is proportional to the strength of the original stimulus

signal detection theory

traditional - assumed that if a signal were intense enough to exceed one's absolute threshold, it would be sensed; didn't take into account the characteristics of the perceiver new - no single absolute threshold; detection depends on a combination of stimulus intensity, background noise, and a person's physical condition, biases, and level of motivation psychologists must sort traits into one of the 4 categories hit or miss - whether or not the signal is present

inner ear

transducer sound waves into neural messages

lens

transparent structure located behind the pupil that actually focuses and bends light as it enters the eye

sensory adaptation

when a constant stimulus is presented for a length of time receptors fire less frequently and the same sensation often fades or disappears does nor affect vision

nearsightedness

when the cornea and lens focus on an image in front of the retina can't see far objects

farsightedness

when the cornea and the lens focus an image behind the retina can't see close objects